Note: Descriptions are shown in the official language in which they were submitted.
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Photopolymerizable thermosetting resin composition
This invention relates to a photosensitive thermosetting resin composition,
more specifically
to a novel photosensitive thermosetting resin composition which is useful as a
solder resist
for a printed wiring board, and a process for forming a solder resist pattern
by coating the
photosensitive thermosetting resin composition, carrying out drying by a dryer
at a constant
temperature, exposing the composition selectively through a film on which a
predetermined
pattern is formed, with active rays, developing an unexposed portion and
further carrying
out heating.
The present invention relates to a photosensitive thermosetting resin
composition which is
suitable as a solder resist having excellent adhesion property, water-soluble
flux resistance,
water resistance, moisture resistance, electric characteristics,
photosensitivity, resolution
property, soldering resistance, chemical resistance, solvent resistance and
whitening
resistance and also has adhesion property on a rust preventive used for
protecting the
circuit of a printed wiring board.
According to the present invention, it becomes possible to cope with
attachment of gas to
surrounding apparatuses caused by gas generation which is a problem when a
printed
wiring board is produced, and environmental problems, etc. caused by gas
generation.
In general, a printed wiring board has been used frequently for incorporating
electronic
parts compactly. The printed wiring board is obtained by etching a copper foil
clad on a
laminate along a circuit wiring, and electronic parts are arranged at
predetermined places
and soldered. A solder resist is used in a step prior to soldering of
electronic parts to such a
printed wiring board, and a film is formed on the entire surface of a circuit
conductor except
portions on which electronic parts are to be soldered. Such a film not only
functions as an
insulating film which prevents soldering from being attached to unnecessary
portions when
soldering is carried out, but also functions as a protective film which
prevents corrosion
caused by oxidation and moisture when a circuit conductor is exposed directly
to air, so that
the film is indispensable. In the prior art, such solder resists have been
formed by screen
printing them on substrates and setting them by UV rays or heat. These solder
resists for
industrial use have been disclosed in, for example, Japanese Patent
Publication No.
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14044/1976.
As a material for public welfare obtained by paying attention to productivity,
a rapid-setting
UV ray-setting type material as disclosed in, for example, Japanese Patent
Publication No.
48800/1986 has been used mainly. However, for the purpose of realizing high
density, a
printed substrate has tended to be made finer and larger in quantity and made
into one
board, its level has been heightened at remarkable speed, and a mounting
system has
been shifted to surface mounting technology (SMT). Accompanied with a finer
printed
substrate and SMT, also in a solder resist, demands for high resolution
property, high
precision and high reliability have been increased, and there have been
proposed from a
screen printing method to a liquid photoresist method which is excellent in
positional
precision and coating property of a conductor edge portion, for both of a
substrate for public
welfare and a substrate for industrial use.
For example, in Japanese Unexamined Patent Publication No. 55914/1982, there
have
been disclosed dry film type photo-sensitive solder resists which comprise
urethane
di(meth)acrylate, a specific linear high molecular weight compound and a
sensitizer. When
these dry film type photo-sensitive solder resists are used for a high density
printed wiring
board, soldering resistance and adhesion property are not sufficient.
As an active energy ray-setting material which can be developed with alkali,
there have
been disclosed materials using, as a base polymer, a reaction product obtained
by reacting
an epoxy resin with an unsaturated monocarboxylic acid and further adding a
polybasic acid
anhydride thereto in Japanese Patent Publication No. 40329/1981 and Japanese
Patent
Publication No. 45785/1982. In Japanese Unexamined Patent Publication No.
243869/1986, there has been disclosed a liquid solder resist composition which
uses a
novolak type epoxy resin, has good heat resistance and chemical resistance and
can be
developed with a dilute alkaline aqueous solution. However, in the above
solder resist
composition, depending on a combination of a polybasic acid anhydride, an
epoxy resin and
an epoxy resin-setting agent to be reacted to make the composition soluble in
an alkaline
developing solution, thermosetting proceeds at the time of drying after
coating a resist,
whereby development failure occurs, or electrolytic corrosion and
discoloration of a copper
foil surface are caused. Further, there are limitations that electric
characteristics are bad
due to influence by a carboxylic acid generated by reacting a polybasic acid
anhydride, heat
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resistance and adhesion property are poor when the amount of an epoxy resin
which is a
thermosetting component used for obtaining characteristics as a solder resist
is small, and it
is difficult to carry out development with a dilute alkaline aqueous solution
when the above
amount is large. Moreover, the above solder resist composition has problems
that setting
by UV rays is slow to require a long exposure time, and sufficient soldering
resistance has
not yet been obtained.
In order to solve these problems, in Japanese Unexamined Patent Publication
No.
50473/1995 and Japanese Patent Publication No. 17737/1995, there have been
disclosed
solder resist compositions comprising a novolak type epoxy resin, particularly
a cresol
novolak epoxy resin-esterified acid adduct, a sensitizer, an epoxy compound,
an epoxy-
setting agent, etc. However, these solder resists have poor photosensitivity,
so that for the
purpose of improving photosensitivity, the amount of a polymerizable vinyl
monomer is
increased, or the amount of a photopolymerization initiator is increased. In
the former case,
tackiness is worsened, so that sticking of a film and attachment of a resist
occur to cause
peeling. In the latter case, although photosensitivity is improved by
increasing the amount
of a photopolymerization initiator to be added, there is a problem that an
unreacted
substance is sublimated at the time of exposure or postcure to foul a
substrate or pollute
environment. For the purpose of protecting the environment of the earth, a
method in which
various kinds of parts are soldered on a printed wiring board and then washed
has come
into question. From the point of protecting environment, a flux to be used for
solving these
problems is subjected to washing with water in place of washing with a
solvent, and water-
soluble fluxes and non-washing type fluxes have been used. Many of these
fluxes are
strongly active and have caused a problem in soldering resistance of a solder
resist, so that
improvement of resistance of the resist has been demanded. Further, surface
mounting is
used in a soldering method, and electroless gold plating is carried out or
rust preventive
treatment is carried out for the purpose of preventing oxidation of a printed
wiring board.
There is a problem of peeling of a resist, caused by these treatments carried
out before
coating a resist or after forming a resist. Further, since a printed wiring
board has high
density, the surface treatment method of a substrate has been shifted
gradually from
mechanical polishing to chemical polishing, so that a demand for adhesion
property on rust
preventive treatment has been increased. With respect to characteristics of a
resist, due to
a demand for high density of a printed substrate, there have been higher
demands for
resolution property, electric characteristics, etc. Existing solder resists
which comprise a
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cresol novolak type epoxy-modified resin as a main component are not
sufficient and also
have a problem in reliability.
With the aim of solving the problem mentioned above, Japanese Patent Kokai Hei
8-41150
has disclosed a solder resist composition comprising an unsaturated group-
containing resin,
a sensitizer, a monomer, a polymerizable prepolymer, an epoxy resin and an
epoxy curing
agent. However, this type of solder resist gives a hard coating film after
cure and is inferior
in adhesiveness. In the gazette mentioned above, a flexible resin such as
polyester polyol
acrylate or polyether polyol acrylate is added in order to improve the
adhesiveness.
However, these materials are hygroscopic and make troubles such as decrease in
developability and appearance of tackiness, so that the good characteristic
properties which
the unsaturated group-containing resin originally has, such as water
resistance,
photosensitivity and heat resistance, are deteriorated by their addition.
Further,
adhesiveness decreases after boiling in water or after thermal hysteresis, so
that
mechanical processability is not good. Further, the composition has a problem
concerning
stability of quality when made into an ink. Thus, although no problem arises
in the initial
stage of use, these compositions exhibit a gradual decrease of developability
when
standing after preliminary drying or show a phenomenon of gelation due to
reactivity after
being made into an ink, so that these compositions cannot be said to be
satisfactory as a
solder resist.
The present invention provides a
photosensitive resin composition which is useful as a liquid photoresist and
can be
developed with a dilute and weakly alkaline aqueous solution, in which with
respect to
operating properties, coating property, drying property, tackiness,
photosetting property,
developability, thermosetting property, a pot life, a shelf Iffe, etc. are
excellent and a printed
wiring board can be formed in a short time, and with respect to
characteristics, soldering
resistance, solvent resistance, chemical resistance, adhesion property,
electric insulating
property, electrolytic corrosion resistance, electric characteristics under
humidification,
plating resistance, adhesion property on a substrate subjected to rust
preventive treatment,
etc. are excellent, all of which are required for a solder resist.
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The present inventors have found that all the problems mentioned above
can be solved or at least mitigated by using
a photopolymerizable thermosetting resin composition which is a compounded
mixture of an
active energy ray-setting resin (a) and a photosensitive prepolymer (b) having
an acid value
of 40-160 mg KOH/g, wherein said ingredient (a) is (i) an unsaturated resin (a-
1) obtained by
reacting an unsaturated monobasic acid copolymer resin with a cycloaliphatic
epoxy group-
containing unsaturated compound or (ii) an unsaturated resin (a-2) obtained by
reacting a
cycloaliphatic epoxy group-containing copolymer resin with an acid group-
containing
unsaturated compound, and said ingredient (b) is selected from the group
consisting of (i) a
prepolymer (b-1) obtained by esterifying a novolak type epoxy compound with an
a,p-
unsaturated carboxylic acid to form a total epoxy groups-esterified product,
followed by
reacting the total epoxy groups-esterified product thus obtained with a
saturated or
unsaturated polybasic acid anhydride, (ii) a prepolymer (b-2) obtained by
esterifying a
novolak type epoxy compound with an a,a-unsaturated carboxylic acid to form a
partial
epoxy groups-esterified product, followed by reacting the partial epoxy groups-
esterified
product thus obtained with a saturated or unsaturated polybasic acid
anhydride, and (iii) a
prepolymer (b-3) obtained by reacting a diisocyanate with a (meth)acrylate
having one
hydroxyl group in one molecule to form a reaction product, followed by
reacting the reaction
product thus obtained with the secondary hydroxyl groups of the above-
mentioned total
epoxy groups-esterified product to form a reaction product, and then reacting
the reaction
product thus obtained with a saturated or unsaturated polybasic acid
anhydride; and the
ingredients (a) and (b) are compounded together at a compounding ratio of 5-
100 parts by
weight of (b) per 100 parts by weight of (a). Based on this finding, the
present invention has
been accomplished.
Thus, the photopolymerizable thermosetting resin composition of the present
comprises
(A) a mixture of an active energy ray-setting resin (a) and a photosensitive
prepolymer (b) having an acid value of 40-160 mg KOH/g,
(B) a diluent,
(C) a photopolymerization initiator,
(D) a setting adhesion-imparting agent and
(E) an epoxy group-containing compound,
wherein said active energy ray-setting resin (a) is selected from the group
consisting of (i) an
unsaturated resin (a-1) obtained by reacting an unsaturated monobasic acid
copolymer resin
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with a cycloatiphatic epoxy group-containing unsaturated compound and (ii) an
unsaturated
resin (a-2) obtained by reacting a cycloaliphatic epoxy group-containing
copolymer resin with
an acid group-containing unsaturated compound;
said photosensitive prepolymer (b) is selected from the group consisting of
(i) a prepolymer
(b-1) obtained by esterifying a novolak type epoxy compound with an a,o-
unsaturated
carboxylic acid to form a total epoxy groups-esterified product, followed by
reacting the total
epoxy groups-esterified product thus obtained with a saturated or unsaturated
polybasic acid
anhydride, (ii) a prepolymer (b-2) obtained =by esterifying a novol"ak type
epoxy compound
with an a,a-unsaturated carboxylic acid to form a partial epoxy groups-
esterified product,
followed by reacting the partial epoxy groups-esterified product thus
obtained.with a
saturated or unsaturated polybasic acid anhydride, and (iii) a prepolymer (b-
3) obtained by
reacting a diisocyanate with a (meth)acrylate having one hydroxyl group in one
molecule to
obtain a reaction product, followed by reacting the reaction product thus
obtained with the
secondary hydroxy groups of the above-mentioned total epoxy groups-esterified
product to
obtain a reaction product, and then reacting the reaction product thus
obtained with a
saturated or unsaturated polybasic acid anhydride;
and the ingredients (a) and (b) are compounded at a compounding ratio of 5-100
parts by
weight of (b) per 100 parts by weight of (a).
In a more specific aspect, the invention provides a photopolymerizable,
thermosetting
resin composition, comprising: (A) a mixture of an active energy ray-setting
resin (a) and
a photosensitive prepolymer (b) having an acid value of 40-160 mg KOH/g; (B) a
diluent;
(C) a photopolymerization initiator; (D) a setting adhesion-imparting agent,
and (E) an
epoxy group-containing compound, wherein: said active energy ray-setting resin
(a) is
selected from the group consisting of (i) an unsaturated resin (a-1) obtained
by reacting
an unsaturated monobasic acid copolymer resin having an acid value of at least
15 mg
KOH/g with a cycloaliphatic epoxy group-containing unsaturated compound,
wherein the
unsaturated resin (a-1) has from 0.2 to 4.0 unsaturated groups per 1,000
molecular
weight, and wherein the unsaturated resin (a-1) has a molecular weight of from
1,000 to
100,000, and (ii) an unsaturated resin (a-2) obtained by reacting a
cycloaliphatic epoxy
group-containing copolymer resin with an acid group-containing unsaturated
compound;
said photosensitive prepolymer (b) is selected from the group consisting of
(i) a
prepolymer (b-1) obtained by esterifying a novolak type epoxy compound with an
a,p-
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unsaturated carboxylic acid to form a total epoxy groups-esterified product,
followed by
reacting the total epoxy groups-esterified product with a saturated or
unsaturated
polybasic acid anhydride, (ii) a prepolymer (b-2) obtained by esterifying a
novolak type
epoxy compound with an a,(3-unsaturated carboxylic acid to form a partial
epoxy groups-
esterified product, followed by reacting the partial epoxy groups-esterified
product with a
saturated or unsaturated polybasic acid anhydride, and (iii) a prepolymer (b-
3) obtained
by reacting a diisocyanate with a (meth)acrylate having one hydroxyl group per
molecule
to obtain a first reaction product, followed by reacting the first reaction
product with the
secondary hydroxy groups of the total epoxy groups-esterified product of (b-1)
to obtain a
second reaction product, and then reacting the second reaction product with a
saturated
or unsaturated polybasic acid anhydride; the ingredients (a) and (b) are
compounded at a
compounding ratio of 5-100 parts by weight of (b) per 100 parts by weight of
(a); and the
formulation ratio of (E) to (A) is at least 75: at most 25.
The preferred formulation ratio of the respective components is 30 to 70, in
particular 40 to
60 parts by weight of (A), 5 to 50 parts by weight of (B), 0.5 to 20, in
particular 3 to 10, parts
by weight of (C), 0.01 to 10, in particular 0..1 to 7, parts by weight of (D)
and 5 to 50, in
particular 10 to 30, parts by weight of (E).
The present invention also relates to the above photopolymerizable
thermosetting resin
compositions which are used as a solder resist.
Further, the present invention also relates to a process for forming a solder
resist pattem,
which comprises coating a printed circuit board with the above
photopolymerizable
thermosetting resin composition, preliminarily drying the coated printed
circuit board,
selectively exposing the coated printed circuit board through a photomask to
an active
energy ray to effect photopolymerization, developing the unexposed area with a
developing
liquid to form a resist pattern and then
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thermosetting the resist pattern by heating.
The coating film of the photosensitive thermosetting resin composition can be
formed by
any method, for example, coating the composition on the entire surface of a
printed wiring
board on which a circuit is formed, by a method using screen printing, a
curtain coater, a roll
coater or a spray coater, or forming the above composition into a dry film and
laminating the
dry film directly on a printed wiring board, or coating the composition in a
liquid state by the
above method and laminating a dry film thereon in a wet state or a dry state.
Thereafter,
the coating film is exposed by direct irradiation of laser rays or selectively
through a
photomask on which a predetermined pattern is formed, with active rays of a
high pressure
mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a
chemical lamp, a
xenon lamp or the like, and an unexposed portion is developed with a
developing solution to
form a resist pattern. Thereafter, the above epoxy compound is thermoset by
heating to
form a solder resist pattem.
In the case of a photosensitive thermosetting resin composition for a solder
resist, in which
a photosensitive prepolymer (a novolak type epoxy resin) is used in
combination of an
epoxy resin as a thermosetting component, there has been generally used an
epoxy resin
which is soluble in an organic solvent. When a photosensitive thermosetting
resin
composition is prepared by using such an epoxy resin, it is estimated that the
epoxy resin is
melted in a state that the epoxy resin is entangled with a photosensitive
prepolymer (a state
that chain length portions of the respective resins are entangled with each
other). As a
result, optical functional groups are settied in a skeleton, so that
photosensitivity is poor,
and time is required for exposure. Further, if a coating film becomes thick,
the
photosensitivity at the inner portion of the coating film is lowered to
enlarge an undercut,
whereby resolution property is poor. In order to improve the photosensitivity
of this type, the
amount of a photopolymerization initiator should be increased, or the amount
of a
photosetting vinyl monomer should be increased. Due to presence of the epoxy
resin, the
crosslinking density of the photosensitive prepolymer is not increased, and
yet the
photosensitive prepolymer is dissolved in a developing solution, so that there
are problems
that the coating film is eroded easily, and sensitivity is worsened.
Therefore, when
soldering is carried out by a water-soluble flux or the like, a white film-
like substance is
generated on the coating film to cause appearance failure. Particularly, a
modified type of
TM
novolak type epoxy resin is not provided with resistance to flux, although K-
183 (produced
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by Alpha-Metal Co.) has flux resistance. However, when operating properties
are ignored
and a vinyl monomer is used in a large amount, resistance is obtained, but
tackiness on
operation becomes strong to cause a problem that contact exposure cannot be
carried out.
There is a means of increasing the amount of a photopolymerization initiator,
a sensitizer or
the like, but an unreacted substance remains in the inner portion of a solder
resist set film to
cause a large number of problems that gas is generated at the time of setting,
a plating
bath is fouled, etc. Further, in order to carry out development with an
alkaline aqueous
solution, when a solder resist is prepared by using a novolak type epoxy-
modified resin,
particularly a cresol novolak type epoxy resin as a base due to influence of a
carboxyl
group, an ester group or the like, electric characteristics are worsened by
absorption of
water generated when development with an alkaline aqueous solution is carried
out, due to
water resistance of the novolak type epoxy resin. Particularly in a printed
substrate used for
vehicles, insulation resistance during humidification is measured, which
cannot be satisfied
by any printed substrate. The water absorption property of the set coating
film is different,
so that water resistance is bad. By these actions, an alkali development type
solder resist
has poor electric characteristics at the time of humidification.
Compared with the above, in an energy ray-setting resin of the present
invention,
particularly addition reaction of cycloaliphatic epoxy groups derived from an
cycloaliphatic
epoxy group-containing unsaturated compound and acid groups derived from an
acrylic
resin, and addition reaction of cycloaliphatic epoxy groups derived from an
cycloaliphatic
epoxy group-containing unsaturated resin and acid groups derived from an acid
group-
containing unsaturated compound proceed easily since the reactivity of ring
opening
reaction of the epoxy groups is high, so that unsaturated groups which can be
set with
active energy ray can be introduced into the resin.
The chemical bond generated by chemical reaction of the acid groups of the
acrylic resin
and the cycloaliphatic epoxy groups is a bond having relatively large steric
hindrance, so
that a film formed from the composition is chemically stable to a hydrolysis-
accelerating
substance (e.g. water, sea water, etc.), whereby remarkable effects which are
excellent in
durabilities such as water resistance, etc. can be obtained. Further, since a
large number of
hydrophobic groups are contained, there is observed an effect that the active
energy ray-
setting resin composition does not absorb water. By both of the effects, the
composition of
the present invention is extremely excellent in electric characteristics as
compared with a
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novolak type epoxy-modified resin. As compared with the sensitivity of a
novolak type
epoxy acrylate acid adduct composition, the sensitivity of the composition of
the present
invention is double or more, resolution property in the case of using a
substrate subjected to
blackening treatment of a multilayer printed wiring board is excellent, and
setting of a
coating film proceeds rapidly, whereby irradiation of UV rays after final
setting is not
required. Further, since setting property is excellent, soldering heat
resistance, particularly
water-soluble flux resistance is excellent.
However, the adhesiveness greatly decreases after boiling in water or after a
thermal
hysteresis. Although the composition has a good developability initially, the
developability
greatly decreases after the composition is allowed to stand at ambient
temperature for 2 or
3 days. It has also been found that an ink prepared therefrom becomes unusable
in one
month after preparation.
Contrariwise, a photosensitive prepolymer (a novolak type epoxy-acrylate acid
adduct) is
introduced into the composition of the present invention for the purpose of
making the best
use of the characteristic feature of the active energy ray-setting resin and
further improving
the properties of the composition. By using these materials in the form of a
mixture, the
problems of individual resins can be solved. Further, a setting adhesion-
imparting agent is
incorporated into the composition of the present invention, by which
adhesiveness can be
improved and the fault of the active energy ray-setting resin can be overcome.
That is, the greatest characteristic of the photosensitive thermosetting resin
composition of
the present invention resides in that a mixture of a specific active energy
ray-setting resin
and a photosensitive prepolymer (a novolak type epoxy-acrylate acid adduct) is
used, and
the setting adhesion-imparting agent is used in combination. A desired solder
resist pattern
for a printed wiring board, which is excellent in various characteristics can
be formed by
coating the composition, carrying out drying, exposure and development and
then
thermosetting the resin together with the epoxy compound by heating or
reacting it with the
photosensitive prepolymer.
In the following, the respective constituting components of the photosensitive
thermosetting
resin composition of the present invention are described.
The unsaturated monobasic acid copolymer resin to be used for preparing the
unsaturated
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resin (a-1) obtained by reaction of the unsaturated monobasic acid copolymer
resin and the
cycloaliphatic epoxy group-containing unsaturated compound of the present
invention is
preferably an acid group-containing acrylic resin. As said acid group-
containing acrylic
resin, there may be used a conventionally known copolymer obtained by
copolymerizing an
ethylenic unsaturated acid such as (meth)acrylic acid, 2-carboxyethyl
(meth)acrylate, 2-
carboxypropyl (meth)acrylate, maleic acid (anhydride), etc. with one or more
monomers
selected from esters of (meth)acrylic acid [e.g. methyl (meth)acrylate, ethyl
(meth)acrylate,
propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,
stearyl
(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate,
etc.], a lactone-
modified hydroxyalkyl (meth)acrylate [e.g. a compound obtained by modifying a
2-
hydroxyalkyl (meth)acrylate such as 2-hydroxyethyl (meth)acrylate, 2-
hydroxypropyl
(meth)acrylate, 2-hydroxybutyl (meth)acrylate, etc. with S-valerolactone, e-
caprolactone or
the like], a vinyl aromatic compound [e.g. styrene, a-methylstyrene,
vinyltoluene, p-
chlorostyrene, etc.], an amide type unsaturated compound [e.g.
(meth)acrylamide,
diacetonacrylamide, N-methylolacrylamide, N-butoxymethylacrylamide, etc.], a
polyolefin
type compound [e.g. butadiene, isoprene, chloroprene, etc.] and other monomer
[e.g.
(meth)acrylonitrile, methyl isopropenyl ketone, vinyl acetate, Beobamonomer (a
product of
Shell Chemical), vinyl propionate, vinyl pivalate, etc.].
In the above unsaturated monobasic acid copolymer resin, it is necessary to
impart
photosetting property to the resin by reacting a part of the acid groups of
said resin with the
epoxy groups of the cycloaliphatic epoxy group-containing unsaturated compound
to
introduce unsaturated groups into the resin. Therefore, it is necessary to
control the acid
value of the unsaturated monobasic acid copolymer resin suitably. The acid
value is in the
range of 15 or more, preferably 30 to 260. Further, as the cycloaliphatic
epoxy group-
containing unsaturated compound to be reacted with said resin, there may be
mentioned a
compound having one radical polymerizable unsaturated group and one
cycloaliphatic
epoxy group in one molecule, for example, a compound having an acroyloxy group
or an
acroyloxyalkyl (the carbon number of the alkyl group is 1 to 6) group on a
ring of an
cycloaliphatic epoxy compound, specifically 3,4-epoxycyclohexylmethyl
(meth)acrylate, 3,4-
epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexylbutyl (meth)acrylate
and 3,4-
epoxycycl oh exyl m ethyl aminoacrylate.
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The reaction of the unsaturated monobasic acid copolymer resin and the
cycloaliphatic
epoxy group-containing unsaturated compound is carried out by, for example,
reacting a
solution of the unsaturated monobasic acid copolymer resin in an inactive
organic solvent
(e.g. an alcohol type, ester type, aromatic hydrocarbon type or aliphatic
hydrocarbon type
solvent, etc.) with the cycloaliphatic epoxy group-containing unsaturated
compound at
about 20 to 120 C for about 1 to 5 hours. In the obtained resin having
unsaturated
groups, the number of the unsaturated groups per the molecular weight of 1,000
is in the
range of 0.2 to 4.0, preferably 0.7 to 3.5. If the number of the unsaturated
groups is less
than 0.2, the setting property of the film is insufficient, and thus adhesion
property to a
material to be coated, water resistance, etc. are poor. On the other hand, if
the number of
the unsaturated groups is more than 4.0, thickening or gelation might be
caused
undesirably during the addition reaction with the acid group-containing resin.
The number average molecular weight of the resin is in the range of 1,000 to
100,000,
preferably 3,000 to 20,000. If the molecular weight is more than 100,000, the
resin has
high viscosity, resulting in inconvenient handling, and also film-forming
property is worsened
undesirably to give a film having poor adhesion property to a materiai to be
coated. The
preferred acid value of the resin is 40 to 250 mgKOH/g, but when weak alkali
is used, the
resin having an acid value not in this range, but in the range of 10 to 250
mgKOH/g can be
used. Even if the acid value is 10 or less, development can be carried out by
using a
solvent, while if the acid value is 250 mgKOH/g or more, the water resistance
of the film
is poor undesirably.
As an cycloaliphatic epoxy group-containing copolymer resin component for
preparing the
unsaturated resin (a-2) by reaction of the cycloaliphatic epoxy group-
containing copolymer
resin and the acid group-containing unsaturated compound of the present
invention, there
may be mentioned a compound having one radical polymerizable unsaturated group
and
one cycloaliphatic epoxy group in one molecule [the above 3,4-
epoxycyclohexylmethyl
(meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3,4-
epoxycyclohexylbutyl
(meth)acrylate, 3,4-epoxycyclohexylmethyl aminoacrylate, etc.] and the above
copolymer
obtained by copolymerization with one or more acrylic or vinyl monomers. As
the acid
group-containing unsaturated compound to be reacted with the epoxy groups of
the
cycloaliphatic epoxy group-containing copolymer resin to introduce unsaturated
groups into
CA 02253242 2004-08-18
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-12-
the resin, there may be mentioned an ethylenic unsaturated acid such as
(meth)acrylic acid,
2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, maleic acid
(anhydride), etc.
As the cycloaliphatic epoxy group-containing copolymer resin ingredient used
for production
of the unsaturated resin (a-2) of the present invention obtained by reacting a
cycloaliphatic
epoxy group-containing copolymer resin with an acid group-containing
unsaturated
compound, there can be referred to copolymers obtained by using a compound
having one
radical-polymerizable unsaturated group and a cycloaliphatic epoxy group in
one molecule
such as the above-mentioned 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-
epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexyl-butyl (meth)acrylate,
3,4-
epoxycyclohexylmethylamino acrylate or the like and the above-mentioned acryl
or vinyl
monomer as essential ingredients and copolymerizing these monomers with one or
more
monomers selected from the same monomers as used in the preparation of the
above-
mentioned unsaturated monobasic acid copolymer resin such as (meth)acrylic
esters, vinyl
aromatic compounds or the like.
The reaction of the cycloaliphatic epoxy group-containing copolymer resin and
the acid
group-containing unsaturated compound is carried out by, for example, reacting
a solution
of the cycloaliphatic epoxy group-containing copolymer resin in an inactive
organic solvent
with the cycloaliphatic epoxy group-containing unsaturated compound at about
20 to
110 C for about 1 to 7 hours. The preferred ranges of the molecular weight,
the number
of unsaturated groups, the acid value, etc. of the obtained resin having
unsaturated groups
are the same as in the case of the above unsaturated resin (a-1).
The resin represented by the following formula is one preferred example of the
active
energy ray-setting resin to be used in the present invention:
CA 02253242 2004-08-18
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-13-
iH3 ~ H3 ~ H3
CH2-C CH2-C CHz-C
COOH b COOCH3
O Oa
OH
RZ
1
O
O-l-e
Ri
(wherein Ri represents a hydrogen atom or a methyl group, R2 represents a
divalent
aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, and a, b and
c each
represent an integer of 0 to 10, provided that a represents at least 1.)
In the above formula, as R2, there may be mentioned a straight or branched
alkylene group,
for example, methylene, ethylene, propylene, tetramethylene, ethylethylene,
pentamethylene, hexamethylene, etc. With respect to the ratio of the above a,
b and c,
a:b:c = 5:3:2 is most preferred. Further, with respect to the ranges of an
acid value and a
molecular weight, the most stable composition having excellent characteristics
can be
obtained in the range of an acid value of 60 to 90 mgKOH/g and a molecular
weight of 400
to 6,000.
A preferred example of the active energy ray-setting resin of the present
invention is an
unsaturated resin obtained by adding epoxy groups of an cycloaliphatic epoxy
compound
substituted by acroyloxyalkyl groups to a part of carboxyl groups of a vinyl
copolymer
containing (meth)acrylic acid and lactone-modified hydroxyalkyl (meth)acrylate
as a
comonomer component, disclosed in Japanese Unexamined Patent Publication No.
TM
41 1 50/1 996. As such an unsaturated resin, ACA-250 produced by Daicel
Chemical
Industries, Ltd. is available.
In the active energy ray-setting type unsaturated resin composition of the
present invention,
the conventionally known photosensitive prepolymer (b-1), (b-2) or (b-3) may
be formulated
suitably depending on use and required coating film properties. These
photosensitive
CA 02253242 2004-08-18
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-14-
prepolymers may be formulated in the range of 50 parts by weight or less,
preferably 5 to
30 parts by weight based on 100 parts by weight of the resin solid content of
the active
energy ray-setting resin composition.
The photosensitive prepolymer (b-1) is a prepolymer having an acid value of 40
to 160
mgKOH/g, obtained by reacting a product in which an etirely esterified product
produced by
esterification reaction of a novolak type epoxy compound and an a,(3-
unsaturated carboxylic
acid, with a saturated or unsaturated polybasic acid anhydride.
The photosensitive prepolymer (b-2) is a prepolymer having an acid value of 40
to 160
mgKOH/g, obtained by reacting a product in which a partially esterified
product produced by
esterification reaction of a novolak type epoxy compound and an a,p-
unsaturated carboxylic
acid, with a saturated or unsaturated polybasic acid anhydride.
As the novolak type epoxy compound to be used in the above entirely esterified
or partially
TM TM TM
esterified product, there may be mentioned YDCN-701, YDCN-704, YDPN-638 and
YDPN-
TM TM TM
602 produced by Tobto Kasei Co.; DEN-431 and DEN-439 produced by Dow Chemical
Co.;
TM TM TM TM TM TM
EPN-1138, EPN-1 235 and EPN-1299 produced by Ciba Geigy AG.; N-730, N-770, N-
865,
w TM TM TM TM TM
N-665, N-673, N-695, VH-4150, VH-4240 and VH-4440 produced by Dainippon Ink &
Chemicals, Inc.; EOCN-120,n EOCN-104 and BRRN-1020 T
produced by Nippon Kayaku Co.,
TM TM TM TM
Ltd.; ECN-265, ECN-293, ECN-285 and ECN-299 produced by Asahi Chemical
Industry
Co., Ltd., etc. A part or all of the novolak type epoxy compound can be
replaced with a
bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, brominated
bisphenol
A type or glycidyl ether type epoxy compound such as amino group-containing,
TM TM
cycloaliphatic, polybutadiene-modified or the like, e.g. Epicoat 828, Epicoat
1007 and
TM TM TM TM
Epicoat 807 produced by Yuka Shell Co.; Epiculon 840, Epiculon 860, Epiculon
3050 and
Epiculon 830 produced by Dainippon Ink & Chemicals Inc.; DER-330, DER-337 and
DER-
36i produced by Dow Chemical Co.; Celloxide 2021 and Celloxide 3000 produced
by Dicel
TM TM
Chemical ldustris, Ltd.; TETRAD-X and TETRAD-C produced by Mitsubisfai.Gas
Chemical
TM TM TM TM
Co. Inc.; EPB-13 and EPB-27 produced by Nippon Soda Co. Ltd.; YD-1 16, YD-128,
YD-
TM TM TM TM TM TM TM TM
013, YD-020, YDG-414, ST-3000, ST-110, YDF-i 90, YDF-2004 and YDF-2007
produced by
TM TM TM TM
Tohto Kasei Co.; GY-260, GY-255 and XB-261 5 produced by Ciba Geigy AG.: DER-
332,
TM TM
DER-662 and DER-542 produced by Dow Chemical Co., etc. It is particularly
preferred to
CA 02253242 1998-10-26
WO 98/00759 PCT/EP97/03141
-15-
use a cresol novolak type epoxy compound as a solder resist for a printed
wiring board.
Next, as the above-mentioned unsaturated monocarboxylic acid, there may be
used acrylic
acid, methacrylic acid, R-styrylacrylic acid, P-furfurylacrylic acid, crotonic
acid, a-
cyanocinnamic acid, cinnamic acid, etc., and half esters of a saturated or
unsaturated
dibasic acid anhydride and a (meth)acrylate having one hydroxy group in one
molecule, or
half esters of a saturated or unsaturated dibasic acid and an unsaturated
monoglycidyl
compound, for example, a half ester obtained by reacting a saturated or
unsaturated
dibasic acid anhydride such as phthalic acid, tetrahydrophthalic acid,
hexahydrophthalic
acid, maleic acid, succinic acid, itaconic acid, chlorendic acid,
methylhexahydrophthalic
acid, methyl-end methylenetetrahydrophthalic acid, methyltetrahydrophthalic
acid, etc. with
hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate,
polyethylene glycol
monoacrylate, glycerin acrylate, trim ethylolpropan e diacrylate,
pentaerythritol triacrylate,
dipentaerythritol pentaacrylate, diacrylate of triglycidyl isocyanurate or a
methacrylate
corresponding to the above acrylate, or the above saturated or unsaturated
dibasic acid
with glycidyl (meth)acrylate at an equimolar ratio according to a conventional
method, etc.,
singly or as a mixture, and acrylic acid is particularly preferably used.
As the above-mentioned saturated or unsaturated polybasic acid anhydride,
there may be
used an anhydride of phthalic acid, tetrahydrophthalic acid, hexahydrophthalic
acid, maleic
acid, succinic acid, itaconic acid, chlorendic acid, methylhexahydrophthalic
acid, methyl-end
methylenetetrahydrophthalic acid, methyltetrahydrophthalic acid, trimellitic
acid, pyromellitic
acid, benzophenonetetracarboxylic acid, etc., particularly preferably
tetrahydrophthalic acid
anhydride or hexahydrophthalic acid anhydride.
The photosensitive prepolymer (b-3) is a prepolymer having an acid value of 40
to 160
mgKOH/g, obtained by reacting a reaction product obtained by reacting a
reaction product
of a diisocyanate and a (meth)acrylate having one hydroxy group in one
molecule with
secondary hydroxy groups of the above entirely esterified product, with a
saturated or
unsaturated polybasic acid anhydride.
As the above diisocyanate, there may be used tolylene diisocyanate, xylylene
diisocyanate,
hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone
diisocyanate,
diphenylmethane diisocyanate, toluidine diisocyanate, lysine diisocyanate,
etc., particularly
CA 02253242 1998-10-26
WO 98/00759 PCT/EP97/03141
-16-
preferably tolyiene diisocyanate or isophorone diisocyanate.
Next, as the above (meth)acrylate having one hydroxy group in one molecule,
there may be
used hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate,
polyethylene
glycol monoacrylate, glycerin diacrylate, trimethylolpropane diacrylate,
pentaerythritol
triacrylate, dipentaerythritol pentaacrylate and diacrylate of
tris(hydroxyethyl) isocyanate or
methacrylates corresponding to the above acrylates, etc., particularly
preferably
hydroxyethyl acrylate or pentaerythritol triacrylate.
The entirely esterified product and the saturated or unsaturated polybasic
acid anhydride to
be used for preparing the photosensitive prepolymer (b-3) are the same as
those to be used
for preparing the photosensitive prepolymer (b-1).
As the diluent (B) to be used in the present invention, there may be mentioned
a
photopolymerizable vinyl type monomer and/or an organic solvent.
Representative
examples of the photopolymerizable vinyl type monomer are hydroxyalkyl
acrylates such as
2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, etc.; mono- or diacrylates
of glycols such
as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol,
propylene glycol, etc.;
acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide, etc.;
aminoalkyl
acrylates such as N,N-dimethylaminoethyl acrylate, etc.; polyvalent acrylates
of polyvalent
alcohols or ethylene oxide or propylene oxide adducts thereof such as
hexanediol,
trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl
isocyanurate, etc.;
phenoxy acrylate, bisphenol A diacrylate and acrylates of ethylene oxide or
propylene oxide
adducts of these phenols, etc.; acrylates of glycidyl ethers such as glycerin
diglycidyl ether,
trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc.; and
melamine acrylate,
and/or methacrylates corresponding to the above acrylates, etc.
On the other hand, as the organic solvent, there may be mentioned ketones such
as ethyl
methyl ketone, cyclohexanone, etc.; aromatic hydrocarbons such as toluene,
xylene,
tetramethylbenzene, etc.; glycol ethers such as methyl cellosolve, butyl
cellosolve,
methylcarbitol, butylcarbitol, propylene glycol monomethyl ether, dipropylene
glycol
monoethyl ether, triethylene glycol monoethyl ether, etc.; esters such as
ethyl acetate, butyl
acetate and esterified products of the above glycol ethers; alcohols such as
ethanol,
propanol, ethylene glycol, propylene glycol, etc.; aliphatic hydrocarbons such
as octane,
CA 02253242 1998-10-26
WO 98/00759 PCT/EP97/03141
-17-
decane, etc.; a petroleum type solvent such as petroleum ether, petroleum
naphtha,
hydrogenated petroleum naphtha, solvent naphtha, etc. and others. The organic
solvent is
used for the purpose of diluting the resin so as to be coated easily.
The diluents (B) as described above are used singly or as a mixture of two or
more of them.
The suitable range of an amount to be used is 20 to 300 parts by weight,
preferably 30 to
150 parts by weight based on 100 parts by weight of the above active energy
ray-setting
resin (A).
The purpose of using the above diluent is to dilute the active energy ray-
setting resin so as
to be coated easily and also to strengthen photopolymerizability in the case
of the
photopoiymerizable vinyl type monomer, or to dissolve and dilute the
photosensitive
prepolymer, whereby the prepolymer can be coated in a liquid state and then
dried to form
a film in the case of the organic solvent. Therefore, depending on the diluent
used, an
exposure system of either a contact system in which a photomask is contacted
with the
coating film or a non-contact system is used.
As a representative example of the photopolymerization initiator (C) to be
used in the
present invention, there may be mentioned benzoins such as benzoin, benzyl,
benzoin
methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl
ether, benzoin
n-butyl ether, etc.; benzoin alkyl ethers; benzophenones such as benzophenone,
p-
methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-
dichlorobenzophenone,
4,4'-bisdiethylaminobenzophenone, etc.; acetophenones such as acetophenone,
2,2-
dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-
dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-[4-
(methylthio)phenyl]-
2-morpholino-l-propanone, N,N-dimethyiaminoacetophenone, etc.; thioxanthones
such as
2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-
diisopropylthioxanthone, etc.; anthraquinones such as anthraquinone,
chioroanthraquinone,
2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-
chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, etc.; ketals
such as
acetophenonedimethylketal, benzyldimethylketal, etc.; benzoates such as ethyl
4-
dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, ethyl p-
dimethylbenzoate, etc.;
phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether,
azobisisobutyronitrile,
tetramethylthiuram disulfide, etc. These photopolymerization initiators can be
used singly or
CA 02253242 2006-08-09
30392-5
- 18 -
in combination of two or more of them.
The suitable range of the amount of these
photopolymerization initiators C to be used is in the range
of 0.2 to 30 parts per weight per l00 parts by weight of
said mixture (A) consisting of active energy ray-setting
resin (a) and photosensitive prepolymer (b).
Further, for the purpose of accelerating
photopolymerization reaction by the above
photopolymerization initiator, a photosensitizer may be used
in combination. As a representative example of such a
photosensitizer, there may be mentioned, for example, known
photosensitizers including tertiary amines such as
triethylamine, triethanolamine, 2-dimethylaminoethanol,
etc., alkylphosphines represented by triphenylphosphine, and
thiols represented by (3-thioglycol.
Next, as the setting adhesion-imparting agent (D),
S-triazine compounds, for example, melamine,
ethyldiamino-S-triazine, 2,4-diamino-S-triazine,
2,4-diamino-6-tolyl-S-triazine,
2,4-diamino-6-xylyl-S-triazine and similar products thereof
are available, and there may be mentioned guanamines such as
guanamine, acetoguanamine, benzoguanamine,
3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl]
2,4,8,10-tetraoxaspiro[5.5]undecane, etc. This S-triazine
compund, etc. not only become a latent setting agent of the
epoxy resin, but also have effects of improving adhesive
strength of a resist substrate and also preventing
electrolytic corrosion and discoloration of copper.
As the imidazole derivative, there may be
mentioned 2HZ-2E4HZTM, C11ZTM, C17ZTM , 2PZTM, 1B2HZTM , 2HZ-CN TM
,
2E4HZ-CNTM, C11Z-CNTM, 2PZ-CNTM, 2P11Z-CNTM, 2HZ-CNSTM,
CA 02253242 2006-08-09
30392-5
- 18a -
2E4HZ-CNSTM, 2PZ-CNSTM, 2HZ-AZINETM, 2E4HZ-AZINETM,
C11Z-AZINETM, 2MA-OKTM, 2P4MHZT"', 2PHZTM , 2P4BHZT"', etc.
produced by Shikoku Chemicals Corporation which accelerate
setting adhesion.
Further, there may be mentioned polyamines such as
diaminodiphenylmethane, m-phenylenediamine,
diaminodiphenylsulfone, cyclohexylamine, m-xylylenediamine,
4,4'-diamino-3,3'-diethyldiphenylmethane,
diethylenetriamine, tetraethylenepentamine,
N-aminoethylpiperazine, isophoronediamine, dicyandiamide,
urea, a urea derivative, polybasic hydrazide, etc. and
organic acid salts and/or epoxy adducts thereof; an amine
complex of boron trifluoride; tertiary amines such as
trimethylamine, triethanolamine, N,N-dimethyloctylamine,
N,N-dimethylaniline, N-benzyldimethylamine, pyridine, N-
CA 02253242 2004-08-18
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-19-
methylpyridine, N-methylmorpholine, hexamethoxymethylmelamine, 2,4,6-
tris(dimethylaminophenol), N-cyclohexyldimethylamine, tetramethylguanidine, m-
aminophenol, etc.; organic phosphines such as tributylphosphine,
triphenylphosphine, tris-
2-cyanoethylphosphine, etc.; phosphonium salts such as tri-n-butyl(2,5-
dihydroxyphenyl)phosphonium bromide, hexadecyltributylphosphonium chloride,
etc.;
quaternary ammonium salts such as benzyltrimethylammonium chloride,
phenyltributylammonium chloride, benzyltrimethylammonium bromide, etc.; a
cationic
photopolymerization catalyst such as diphenyliodonium tetrafluoroborate,
triphenylsulfonium
hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate,
Irgacure 261
produced by Ciba Geigy AG, etc.; a styrene-maleic acid resin, a silane
coupling agent, etc.
It is sufficient that the amount of the setting adhesion-imparting agent (D)
as described
above to be used is a general quantitative rate. For example, when
dicyandiamide,
mercaptotriazole and a silane coupling agent are used with the active energy
ray-setting
resin of the present invention, since adhesion property to copper is
excellent, adhesion
property to a rust preventive used for preventing oxidation is improved. With
respect to the
ratio thereof, 0.5 to 5 % by weight of a mixture of the setting adhesion-
imparting agents at a
ratio of 1:1:0.5 is mixed based on 100 parts by weight of the active energy
ray-setting resin.
Next, as the compound (E) having epoxy groups, there may be used a solid or
liquid known
epoxy compound, and said epoxy compound is used depending on required
characteristics.
For example, when plating resistance is to be improved, a liquid epoxy resin
is used, and
when water resistance is required, an epoxy resin having a large number of
methyl groups
on a benzene ring or a cyclo ring. As a preferred epoxy resin, there may be
mentioned a
TM
bisphenol S type epoxy resin such as BPS-200 produced by Nippon Kayaku Co.,
Ltd., EPX-
TM fM
30 produced by ACR Co., Epiculon EXA-1 514 produced by Dainippon Ink &
Chemicals Inc.,
TM
etc.; a diglycidyl phthalate resin such as Blemmer DGT produced by Nippon Oil
and Fats
TM
Co., Ltd., etc.; a heterocvclic epoxy resin such as TEPIC produced by Nissan
Chemical
TM
Industries, Ltd., Araldite PT810 produced by Ciba Geigy AG., etc.; a bixylenol
type epoxy
TM
resin such as YX-4000 produced by Yuka Shell Co., etc.; a bisphenol type epoxy
resin such
TM
as YL-6056 produced by Yuka Shell Co., etc.; a tetraglycidyl xylenoylethane
resin such as
ZX-1063 produced by Tohto Kasei Co., etc.; a novolak type epoxy resin such as
EPPN-201;M
EOCN-103,A EOCN-1020,~ EOCN-1025 and BRRN produced by Nippon Kayaku Co., Ltd.,
TM TM TM
ECN-278, ECN-292 and ECN-299 produced by Asahi Chemical Industry Co., Ltd.,
ECN-
CA 02253242 2004-08-18
30392-5
-20-
TM TM TM TM TM
1273 and ECN-1299 produced by Ciba Geigy AG., YDCN-220L, YDCN-220HH, YDCN-702,
YDCN-704, YDPN-601Mand YDPN-602 produced by Tohto Kasei Co., Epiculon-673, N-
680,
N-695, N-770 and N-775 produced by Dainippon Ink & Chemicals Inc., etc.; a
novolak type
epoxy resin of bisphenol A such as EPX-8001,A EPX-8002,mEPPX-8060 and EPPX-
8061M
TM
produced by Asahi Chemical Industry Co., Ltd., Epiculon N-880 produced by
Dainippon Ink
TM TM
& Chemicals Inc., etc.; a chelate type epoxy resin such as EPX-49-69 and EPX-
49-30
produced by Asahi Denka Kogyo K.K., etc.; a glyoxal type epoxy resin such as
YDG-414M
produced by Tohto Kasei Co., etc.; an amino group-containing epoxy resin such
as YH-
1402 TM TM produced by Tohto Kasei Co., YL-931 and YL-933 produced by Yuka
Shell Co., etc.; a rubber-modified epoxy resin such as Epiculon TSR-601
produced by
Dainippon Ink & Chemicals Inc., EPX-84-2 and EPX-4061Mproduced by Asahi Denka
Kogyo
TM
K.K., etc.; a dicyclopentadiene phenolic type epoxy resin such as DCE-400
produced by
Sanyo-Kokusaku Pulp Co., Ltd., etc.; a silicone-modified epoxy resin such as X-
1359 TM
produced by Asahi Denka Kogyo K.K., etc.; an E-caprolactone-modified epoxy
resin such as
TM
Plaaue G-402 and G-710 produced by Dicel Chemical Industries, Ltd., etc. and
others.
Further, partially esterified compounds by (meth)acrylates of these epoxy
compounds can
be used in combination.
The formulation ratio of the compound (E) having epoxy groups to the mixture
of the active
energy ray-setting resin and said photosensitive prepolymer (A) is 75 or
more:25 or less,
preferably 80 or more:20 or less in terms of weight ratio. If the ratio of (E)
exceeds 25, the
solubility of an unexposed portion with a developing solution is lowered to
give an
undeveloped portion easily in the case of alkali development, and the coating
film is eroded
to cause falling or blistering of the coating film easily in the case of
solvent development,
which makes practical use difficult.
The carboxyl groups of the active energy ray-setting resin (A) and the epoxy
groups of the
epoxy compound (E) are reacted by ring opening polymerization, and when a
particulate
epoxy resin is used, it is necessary to use a setting agent in combination.
When the setting
adhesion-imparting agent (D) is used in combination at the above formulation
ratio,
sufficient crosslinking is effected to improve water resistance and heat
resistance,
particularly water-soluble flux resistance and electroless gold plating
resistance. Therefore,
the composition maintains characteristics which are not possessed by a novolak
type epoxy
resin-modified solder resist and functions as an excellent solder resist
sufficiently.
CA 02253242 2004-08-18
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-21-
In the photosensitive thermosetting resin composition of the present
invention, for the
purpose of improving characteristics such as adhesion property, hardness,
etc., if
necessary, there may be used a known inorganic filler such as barium sulfate,
barium
titanate, silicon oxide powder, particulate silicon oxide, amorphous silica,
talc, clay,
magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide,
mica
powder, etc. Its formulation ratio is 0 to 60 % by weight, preferably 5 to 40
% by weight of
the photosensitive thermosetting resin composition.
Further, if necessary, there may be used known additives such as a known
coloring agent
such as Phthalocyanine Blue, Phthalocyanine Green, Iodine Green, Disazo
Yellow, Crystal
Violet, titanium oxide, carbon black, naphthalene black, etc., a known
thermopolymerization
inhibitor such as hydroquinone, hydroquinone monomethyl ether, tert-
butylcatechol,
pyrogallol, phenothiazine, etc., a known thickener such as asbestos, orbene,
bentone,
montmorillonite, etc., a silicone type, fluorine type or high molecular weight
type defoaming
agent and/or a leveling agent and an antioxidant.
A diallyl phthalate prepolymer or a diallyl isophthalate prepolymer which is
an allyl
compound can be added as an organic filler, and by addition of these
prepolymers,
chemical resistance can be improved. The amount to be added is up to 30 parts
by weight,
preferably up to 20 parts by weight based on 100 parts by weight of the active
energy ray-
rM TM
setting resin. As said prepolymer, Daiso-Dap and Daiso-isodap produced by
Osaka Soda
Co., Ltd., etc. are available, and a prepolymer having an average molecular
weight of 2,000
to 30,000 is used. A diallyl isophthalate prepolymer having an average
molecular weight of
5,000 to 20,000 is particularly preferred.
For the purpose of increasing impact resistance of a set coating film, there
may be used
copolymers of ethylenic unsaturated compounds such as acrylates, etc., a known
binder
resin such as polyester resins synthesized from a polyvalent alcohol and a
saturated or
unsaturated polybasic acid compound, etc., and a known photosensitive oligomer
such as
polyester (meth)acrylates synthesized from a poiyvalent alcohol, a saturated
or unsaturated
polybasic acid compound and glycidyl (meth)acrylate, and urethane
(meth)acrylates
synthesized from a polyvaient alcohol, a diisocyanate and a hydroxy group-
containing
(meth)acrylate, etc. in the range which does not exert influence on various
characteristics
CA 02253242 2004-08-18
30392-5
-22-
as a solder mask. However, among the above components, with respect to the
copolymers
of ethylenic unsaturated compounds such as acrylates, etc. and the binder
material such as
polyester resins, etc., if the amount of the copolymers and the known binder
resin having no
photosensitive group to be used is large, there are problems that
developability and
sensitivity are worsened, etc., so that the amount to be used is desirably 10
% by weight or
less based on the active energy ray-setting resin (about 5 % by weight or less
of the whole
composition).
The developing solution for forming a solder resist pattern after-exposing the
photosensitive
thermosetting resin composition of the present invention through a photomask
varies
depending on selection of the active energy ray-setting resin, but as the
organic solvent,
there may be used an organic solvent such as cyclohexanone, xylene,
tetramethylbenzene,
butyl cellosolve, butylcarbitol, propylene glycol monomethyl ether, cellosolve
acetate,
propanol,.propyiene glycol, trichloroethane, trichioroethylene, modified
trichloroethane
TM TM
(Ethana IR produced by Asahi Chemical Industry Co., Ltd., Three One EX-R
produced by
T,,,
Toa Gosei Chemical Industry Co., Ltd., Kandentriethan SR-A produced by Kanto
Denka
TM
Kogyo Co., Ltd. and Resi Solve V-5 produced by Asahi Glass Company, Limited),
etc.,
and/or an alkaline aqueous solution of potassium hydroxide, sodium hydroxide,
sodium
carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia,
amines or
the like, and/or an aqueous surfactant solution, etc.
The photosetting thermosetting resin composition of the present invention is
coated on a
substrate so as to have a desired thickness and then heated at 60 to 80 C for
15 to 60
minutes to volatilize the organic solvent. Then, a desired pattern in which an
image portion
is transparent is placed in a contacted state on the coating film of the
substrate, and the
desired pattern is exposed selectively by irradiating UV rays. By exposure,
the composition
in the exposed region of the coating film generates crosstinking to become
insoluble. Next,
by removing the unexposed region with a dilute alkaline aqueous solution, the
coating film
is developed. The dilute alkaline aqueous solution to be used here is
generally a 0.5 to 5 %
by weight aqueous sodium carbonate solution. As a matter of course, other
alkali can be
also used. In order to improve heat resistance, it is desired to apply UV
rays, heat at 100 to
200 C or far infrared rays later to the pattern thus obtained to effect
secondary setting.
CA 02253242 1998-10-26
WO 98/00759 PCT/EP97/03141
-23-
In the following, the present invention is described specifically by referring
to Preparation
examples, Examples and Comparative examples, but the present invention is not
limited
thereto. "Part" and "%" are all based on weight unless otherwise indicated.
Preparation example 1 (unsaturated resin)
A mixed solution comprising 20 parts by weight of methyl methacrylate, 20
parts by weight
of styrene, 25 parts by weight of methyl acrylate, 15 parts by weight of 2-
hydroxyethyl
methacrylate, 20 parts by weight of acrylic acid and 5 parts by weight of
azobisisobutyronitrile was added dropwise over 3 hours to 60 parts by weight
of butyl
cellosolve in a reactor maintained at 105 C under nitrogen gas atmosphere.
After
dropwise addition, the mixture was aged for 1 hour. A mixed solution
comprising 1 part by
weight of azobisdimethylvaleronitrile and 7 parts by weight of butyl
cellosolve was added
dropwise over 1 hour to the mixture, and the resulting mixture was further
aged for 5 hours
to obtain a high acid value acrylic resin (acid value: 150) solution. Next, to
this solution
were added 25 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate and
0.06 part by
weight of hydroquinone, and the mixture was reacted at 80 C for 5 hours while
blowing air
into the mixture to obtain a solution of an unsaturated resin (acid value: 60,
the number of
unsaturated groups: 1.1/molecular weight of 1,000, number average molecular
weight:
10,000).
Preparation example 2 (unsaturated resin)
A mixed solution comprising 30 parts by weight of styrene, 35 parts by weight
of butyl
acrylate, 35 parts by weight of acrylic acid and 3 parts by weight of
azobisisobutyronitrile
was added dropwise over 3 hours to 60 parts by weight of diethylene glycol
dimethyl ether
in a reactor maintained at 110 C under nitrogen gas atmosphere. After
dropwise addition,
the mixture was aged for 1 hour. A mixed solution comprising 1 part by weight
of
azobisdimethylvaleronitrile and 20 parts by weight of diethylene glycol
dimethyl ether was
added dropwise over 1 hour to the mixture, and the resulting mixture was
further aged for 5
hours to obtain a high acid value acrylic resin (acid value: 260) solution.
Next, to this
solution were added 65 parts by weight of 3,4-epoxycyclohexylmethyl
methacrylate and
0.14 part by weight of hydroquinone monomethyl ether, and the mixture was
reacted at 80
C for 5 hours while blowing air into the mixture to obtain a solution of an
unsaturated resin
(acid value: 40, the number of unsaturated groups: 1.4/molecular weight of
1,000, number
average molecular weight: 13,000).
CA 02253242 1998-10-26
WO 98/00759 PCT/EP97/03141
-24-
Preparation example 3 (unsaturated resin)
A mixed solution comprising 30 parts by weight of styrene, 35 parts by weight
of butyl
acrylate, 35 parts by weight of acrylic acid and 3 parts by weight of
azobisisobutyronitrile
was added dropwise over 3 hours to 50 parts by weight of n-butanol and 40
parts by weight
of diethylene glycol dimethyl ether in a reactor maintained at 110 C under
nitrogen gas
atmosphere. After dropwise addition, the mixture was aged for 1 hour. A mixed
solution
comprising 1 part by weight of azobisdimethylvaleronitrile and 40 parts by
weight of
diethylene glycol dimethyl ether was added dropwise over 1 hour to the
mixture, and the
resulting mixture was further aged for 5 hours to obtain a high acid value
acrylic resin (acid
value: 260) solution. Next, to this solution were added 75 parts by weight of
3,4-
epoxycyclohexylmethyl methacrylate and 0.14 part by weight of hydroquinone
monomethyl
ether, and the mixture was reacted at 80 C for 5 hours while blowing air into
the mixture to
obtain a solution of an unsaturated resin (acid value: 20, the number of
unsaturated groups:
1.98/molecular weight of 1,000, number average molecular weight: 15,000).
Preparation example 4 (unsaturated resin)
A mixed solution comprising 40 parts by weight of butyl methacrylate, 35 parts
by weight of
butyl acrylate, 25 parts by weight of acrylic acid and 1 part by weight of
azobisisobutyronitrile was added dropwise over 3 hours to 90 parts by weight
of diethylene
glycol dimethyl ether in a reactor maintained at 110 C under nitrogen gas
atmosphere.
After dropwise addition, the mixture was aged for 1 hour. A mixed solution
comprising 1
part by weight of azobisdimethylvaleronitrile and 10 parts by weight of
diethylene glycol
dimethyl ether was added over 1 hour to the mixture, and the resulting mixture
was further
aged for 5 hours to obtain a high acid value acrylic resin (acid value: 184)
solution. Next, to
this solution were added 60 parts by weight of 3,4-epoxycyciohexylmethyl
methacrylate and
0.12 part by weight of hydroquinone, and the mixture was reacted at 80 C for
5 hours
while blowing air into the mixture to obtain a solution of an unsaturated
resin (acid value: 0,
the number of unsaturated groups: 2.07/molecular weight of 1,000, number
average
molecular weight: 30,000).
Preparation example 5 (unsaturated resin)
A mixed solution comprising 25 parts by weight of styrene, 23 parts by weight
of butyl
acrylate, 52 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate and 3
parts by
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30392-5
-25-
weight of t-butylperoxy-2-ethylhexynoate was added dropwise over 3 hours to 90
parts by
weight of butyl cellosolve in a reactor maintained at 110 C under nitrogen
gas
atmosphere. After dropwise addition, the mixture was aged for 1 hour. A mixed
solution
comprising 1 part by weight of t-butylperoxy-2-ethylhexynoate and 10 parts by
weight of
butyl cellosolve was added over 1 hour to the mixture, and the resulting
mixture was further
aged for 7 hours to obtain an cycloaliphatic epoxy group-containing acrylic
resin solution.
Next, to this solution were added 16 parts by weight of acrylic acid and 0.12
part by weight
of hydroquinone, and the mixture was reacted at 80 C for 7 hours while
blowing air into
the mixture to obtain a solution of an unsaturated resin (acid value: 0, the
number of
unsaturated groups: 1.8/molecular weight of 1,000, number average molecular
weight:
12,000).
Preaaration examr)le 6 (photosensitive prepolvmer)
TM
1090 parts of a cresol novolak type epoxy resin (YDCN-702 produced by Tohto
Kasei Co.)
having an epoxy equivalent of 215 was charged into a three-necked flask
equipped with a
stirrer and a cooling device and melted by heating at 90 to 100 C and
stirred. Next, to the
resin were added 390 parts of acrylic acid, 1.0 part of hydroquinone and 2.0
parts of
benzyldimethylamine. Next, the temperature of the mixture was elevated to 110
to 115 C,
the mixture was reacted under stirring for 12 hours, and the reaction mixture
was taken out
from the reaction apparatus and cooled to room temperature to obtain a product
entirely
esterified by acrylic acid of the novolak type epoxy compound having an acid
value of 3.0
mgKOH/g. 450 parts of this product, 125 parts of ethylcarbitol acetate and 125
parts of
TM
Ipsoi #150 (produced by Idemitsu Oil Co.) were charged into a reaction
apparatus and
dissolved by heating to 70 to 80 C. Next, the 1 hydroxy group equivalent of
the solution
was reacted with 0.5 mole of tetrahydrophthalic acid anhydride. A solution of
an acid
anhydride adduct of the product entirely esterified by acrylic acid of the
novolak type epoxy
compound having an acid value of 58 mg KOH/g in an organic solvent was
obtained.
Preparation example 7 (ahotosensitivepregolymer)
Reaction was carried out in the same manner as in Preparation example 6 except
that the
amount of acrylic acid was changed to 250 parts. A product partially
esterified by acrylic
acid of the novolak type epoxy compound having an acid value of 0.5 mgKOH/g
was
TM
obtained. 450 parts of this product, 125 parts of ethycarbitol acetate and 125
parts of Ipsol
#150 (produced by ldemitsu Oil Co.) were charged into a reaction apparatus and
dissolved
CA 02253242 2004-08-18
30392-5
-26-
by heating to 70 to 80 C. Next, the 1 hydroxy group equivalent of the
solution was reacted
with 0.5 mole of tetrahydrophthalic acid anhydride. A solution of an acid
anhydride adduct of
the product partially esterified by acrylic acid of the novolak type epoxy
resin having an acid
value of 58 mgKOH/g in an organic solvent was obtained.
Examole 1
The resin obtained in Production Example 1 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylofpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
isopropyithioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
CA 02253242 2004-08-18
30392-5
-27-
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
The above-mentioned ingredients were preliminarily blended and then twice
kneaded by
means of a tripie roll mill to prepare a photosensitive thermosetting resin
composition. The
composition had a particle size of 15 m or less. The composition obtained
herein was
coated onto whole surface of a copper through-hole printed circuit board by
the method of
screen printing, introduced into a hot air circulation oven and dried at 80 C
for 20 minutes,
and photo-cured by irradiating thereto an ultraviolet ray having a wavelength
of 365 nm
through an artwork at an integrated dose of 150 mJ/cm2 as measured with an
integrating
photometer manufactured by Orc Seisakusho Co. Then, development was carried
out in a
1% by weight aqueous solution of sodium carbonate as a developing solution at
a spray
pressure of 2.0 kg/cm2 for 60 seconds, and then heat-cure was carried out for
60 minutes in
a hot air circulation type curing oven kept at 150 C to form a solder resist
pattern.
Example 2
The resin obtained in Production Example 1 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 7 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 3.0 parts
Trimethylolpropane triacrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowien AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
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30392-5
-28-
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 m or less. A solder resist pattern was
prepared from this
photosensitive thermosetting resin composition by repeating the procedure of
Example 1,
except that the composition was coated on whole surface of a copper through-
hole printed
circuit board by the method of screen printing, and the coated matter was
introduced into a
hot air circulation type oven and dried at 80 C for 20 minutes.
CA 02253242 2004-08-18
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-29-
Example 4
The resin obtained in Production Example 2 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 um or less. A solder resist pattern was
formed from this
photosensitive thermosetting resin composition by repeating the procedure of
Example 1,
except that the composition was coated on whole surface of a copper through-
hole printed
circuit board by the method of screen printing, and the coated matter was
introduced into a
hot air circulation type oven and dried at 80 C for 20 minutes.
Examgle 5
The resin obtained in Production Example 3 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
CA 02253242 2004-08-18
30392-5
-30-
TM
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Siiane coupler 0.5 part
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 m or less. A solder resist pattern was
formed from this
photosensitive thermosetting resin composition by repeating the procedure of
Example 1,
except that the composition was coated on whole surface of a copper through-
hole printed
circuit board by the method of screen printing, the coated matter was
introduced into a hot
air circulation type oven and dried at 80 C for 20 minutes, and 1% by weight
solution of
potassium hydroxide was used as the developer.
am le 6
The resin obtained in Production Exampie 4 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
Irgacure 907 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
AerosilT~200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
CA 02253242 2004-08-18
30392-5
-31 -
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 m or less. A solder resist pattern was
formed from this
photosensitive thermosetting resin composition by repeating the procedure of
Example 1,
except that the composition was coated on whole surface of a copper through-
hole printed
circuit board by the method of screen printing, the coated matter was
introduced into a hot
air circulation type oven and dried at 80 C for 20 minutes, and cyclohexanone
was used as
the developer.
Example 7
The resin obtained in Production Example 5 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
Irgacure 907 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazo{e 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
CA 02253242 2004-08-18
30392-5
-32-
composition thus obtained was 15 m or less as measured with Grindmeter
manufactured
by Erichsen Co.. A solder resist pattern was formed from this photosensitive
thermosetting
resin composition by repeating the procedure of Example 1, except that the
composition
was coated on whole surface of a copper through-hole printed circuit board by
the method
of screen printing, the coated matter was introduced into a hot air
circulation type oven and
dried at 80 C for 20 minutes, and cyclohexanone was used as the developer.
Example 8
TM
Active energy ray-setting resin [ACA-250, manufd. by Daicel Chemical] 30.0
parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
lsopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 m or less as measured with Grindmeter
manufactured
by Erichsen Co.. A solder resist pattern was formed from this photosensitive
thermosetting
resin composition by repeating the procedure of Example 1, except that the
composition
was coated on whole surface of a copper through-hole printed circuit board by
the method
of screen printing.
CA 02253242 2004-08-18
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-33-
Example 9
TM
Active energy ray-setting resin [ACA-250, manufd. by Daicel Chemical] 30.0
parts
The resin obtained in Production Exampie 7 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethyiolpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy Co.) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 16.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) _ 1.0 part.
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, these ingredients were twice kneaded by means of
a triple roll
mill to obtain a photosensitive thermosetting resin composition. Particle size
of the
composition thus obtained was 15 um or less as measured with Grindmeter
manufactured
by Erichsen Co.. A solder resist pattern was formed from this photosensitive
thermosetting
resin composition by repeating the procedure of Example 1, except that the
composition was
coated on whole surface of a copper through-hole printed circuit board by the
method of
screen printing, and the coated matter was introduced into a hot air
circulation type oven and
driect at 80 C for 20 minutes.
CA 02253242 2004-08-18
30392-5
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Comparative Example 1
The resin obtained in Production Example 1 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 19.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
CA 02253242 2004-08-18
30392-5
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing and the coated matter
was
introduced into a hot air circulation type oven and dried at 80 C for 20
minutes.
Comparative Example 2
The resin obtained in Production Example 1 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
Irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
lsopropylthioxanthone 1.0 part
Barium sulfate 20.5 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing and the coated matter
was
introduced into a hot air circulation type oven and dried at 80 C for 20
minutes.
CA 02253242 2004-08-18
30392-5
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Comparative Example 3
The resin obtained in Production Example 2 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 19.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a- preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing, the coated matter
was introduced
into a hot air circulation type oven and dried at 80 C for 20 minutes, and a
1% by weight
solution of potassium hydroxide was used as the developer.
Comparative Example 4
The resin obtained in Production Example 3 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
Irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 19.0 parts
CA 02253242 2004-08-18
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Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing, the coated matter
was introduced
into a hot air circulation type oven and dried at 80 C for 20 minutes, and a
1% by weight
solution of potassium hydroxide was used as the developer.
Comparative Example 5
The resin obtained in Production Example 4 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 19.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil 1.0 part
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
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TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing, the coated matter
was introduced
into a hot air circulation type oven and dried at 80 C for 20 minutes, and
cyclohexanone
was used as the developer.
Comparative Example 6
The resin obtained in Production Example 5 (unsaturated resin) 35.0 parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
lrgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 19.0 parts
Finely powdered talc 1.0 part
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
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printed circuited board by the method of screen printing, the coated matter
was introduced
into a hot air circulation type oven and dried at 80 C for 20 minutes, and
cyclohexanone
was used as the developer.
Comparative Example 7
TM
Active energy ray-setting resin [ACA-250, manufd. by Daicel Chemical] 35.0
parts
Dipentaerythritol hexaacrylate 15.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
lrgacure 369 (manufd. by Ciba Geigy) 3.0 parts
lsopropylthioxanthone 1.0 part
Barium sulfate - 19.0 parts
Finely powdered talc 3.0 parts
TM
Aerosil #200 (manufd by Japan Aerosil) 1.0 part
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
Mercaptotriazole 1.0 part
Silane coupler 0.5 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
After a preliminary blending, the above-mentioned ingredients were twice
kneaded by
means of a triple roll mill to obtain a photosensitive thermosetting resin
composition.
Particle size of the composition was 15 m or less as measured with Grindmeter
manufactured by Erichsen Co. A solder resist pattern was formed from the
photosensitive
thermosetting resin composition thus obtained by repeating the procedure of
Example 1,
except that the composition was coated onto whole surface of a copper through-
hole
printed circuited board by the method of screen printing and the coated matter
was
introduced into a hot air circulation type oven and dried at 80 C for 20
minutes.
Comparative Example 8
The resin obtained in Production Example 1 (unsaturated resin) 45.0 parts
Diallyl phthalate prepolymer (manufd. by Osaka Soda Co.) 5.0 parts
Cellosolve acetate 5.0 parts
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Trimethylolpropane triacrylate 4.0 parts
Triethyleneglycol diacrylate 3.0 parts
2-Methyl-1 -[4-(methylthio)phenyl]-2-morpholinopropan-1-one 3.0 parts
2,4-Diisopropylthioxanthone 2.5 parts
Clay 11.0 parts
Finely powdered talc 5.0 parts
Phthalocyanine Green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 12.0 parts
Dicyandiamide 2.0 parts
TM
2E4NZ-CNS (curing agent manufd. by Shikoku Kasei Kogyo Co.) 1.0 part
Total 100.0 parts
A photosensitive thermosetting resin composition was prepared by repeating the
procedure
of Example 1, except that the ingredients to be compounded were altered to
those
mentioned above. Particle size of the composition thus obtained was 25 m or
less. A
solder resist pattern was formed by repeating the procedure of Example 1,
except that the
photosensitive thermosetting resin composition obtained herein was coated onto
whole
surface of a copper through-hole printed circuit board by the method of screen
printing.
Comparative Examole 9
The resin obtained in Production Example 6 (photosensitive prepolymer) 30.0
parts
Butyl cellosolve 11.5 parts
Pentaerythritol tetraacrylate 5.0 parts
Hydroxycyclohexyl phenyl ketone 3.0 parts
N,N-Dimethylaminoacetophenone 1.0 part
Barium sulfate 10.0 parts
Finely powdered talc 4.0 parts
Phthalocyanine Green 0.5 part
TM
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
TM
EPX-30 (manufd. by Asahi Denka Kogyo) 15.0 parts
TM
2PHZJ 1.0 part
Total 82.0 parts
A photosensitive thermosetting resin composition was prepared by repeating the
procedure
of Example 1, except that the ingredients to be compounded were altered to
those
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mentioned above. Particle size of the composition thus obtained was 25 m or
less. A
solder resist pattern was formed by repeating the procedure of Example 1,
except that the
photosensitive thermosetting resin composition obtained herein was coated onto
whole
surface of a copper through-hole printed circuit board by the method of screen
printing.
Comparative Example 10
The resin obtained in Production Example 7 (photosensitive prepolymer) 35.0
parts
Carbitol* acetate 10.0 parts
Dipentaerythritol hexaacrylate 3.0 parts
Diethyleneglycol diacrylate 3.0 parts
Benzil dimethyl ketal 3.0 parts
N,N-Dimethylaminoacetophenone 1.5 part
Barium sulfate 10.0 parts
Amorphous silica 15.0 parts
Phthalocyanine Green 0.5 part
rm
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.5 part
rM
Araldite PT810 (manufd. by Ciba Geigy) 15.0 parts
Dicyandiamide 2.0 parts
2P4MHZ (curing agent manufd. by Shikoku Kasei Kogyo Co.) 0.5 part
Total 100.0 oarts
A light exposure type thermosetting resin composition was prepared by
repeating the
procedure of Example 1, except that the ingredients to be compounded were
altered to
those mentioned above. Particle size of the composition thus obtained was 20
m or less.
Using the light exposure type thermosetting resin composition obtained herein,
a solder
resist pattern was formed by repeating the procedure of Example 1=.
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Comparative Example 12
The resin obtained in Production Example 1 (unsaturated resin) 30.0 parts
The resin obtained in Production Example 6 (photosensitive prepolymer) 10.0
parts
Dipentaerythritol hexaacrylate 13.0 parts
Trimethylolpropane acrylate 4.0 parts
TM
Irgacure 369 (manufd. by Ciba Geigy) 3.0 parts
Isopropylthioxanthone 1.0 part
Barium sulfate 17.5 parts
Finely powdered talc 3.0 parts
TM
Aerosit #200 (manufd. by Japan Aerosil) 1.0 part
Phthalocyanine green 0.5 part
Flowlen AC-300 (manufd. by Kyoueisha Yushi Co.) 1.0 part
Dicyandiamide 1.0 part
TM
YX-4000 (manufd. by Yuka Shell Co.) 15.0 parts
Total 100.0 parts
A light exposure type thermosetting resin composition was prepared by
repeating the
procedure of Example 1, except that the ingredients to be compounded were
altered to
those mentioned above. Particle size of the composition thus obtained was 20
m or less.
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Using the light exposure type thermosetting resin composition obtained herein,
a solder
resist pattern was formed by repeating the procedure of Example 1.
The solder resist resin compositions obtained in Examples 1-10 and Comparative
Examples
1-12 were examined on characteristic properties. The results are shown in
Table 1 and
Table 2.
Each of the photosensitive solder resists prepared in Examples 1-10 and
Comparative
Examples 1-12 was coated up to a coating thickness of 30-40 m by the method
of screen
printing on the whole surface of a surface-treated and patterned copper-clad
laminate
board. Then, the coated laminate board was dried for 20 minutes in a hot air
circulation
type drying oven kept at 80 C. After intimately contacting a negative film of
desired pattern
with the resist, the resist was exposed to an ultraviolet ray having an
intensity of 25 mW/cm2
at a wavelength of 365 nm for a period of 10 seconds, until the integrated
dose of the
ultraviolet irradiation reached 150 mJ/cm2 as measured with integrating
photometer
manufactured by Orc Seisakusho Co., provided that Comparative Samples 9-11
were made
into test pieces by irradiating them at a dose of 750 mJ/cm2, because
characteristic
properties of these comparative samples could not be measured when made into
test
pieces on the same dose level as above. After development for 60 seconds using
a 1 % by
weight aqueous solution of sodium carbonate (in some experiments, 1% KOH
solution or
cyclohexanone was used as the developer), the developed test pieces were heat-
cured in a
hot air circulation type oven kept at 150 C for 60 minutes. On the samples
thus obtained,
dryness to the touch after the drying treatment, photosensitivity,
developability (the state of
coating film after development), adhesiveness, hardness of coating film, acid
resistance,
alkali resistance, solvent resistance, plating resistance, solder resistance,
K-183 flux
resistance, insulation resistance, insulation resistance in a humidified
atmosphere,
resolution property, water absorption rate, sensitivity, odor after exposure
to light, boiling
adhesiveness, re-heating adhesiveness, standing developability and time-
dependent
change were tested and evaluated.
Various properties in the following Tables 1 and 2 were tested, evaluated and
judged as
described below.
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1) Dry tackiness
After the composition was coated on a copper through etching circuit substrate
by screen
printing, the substrate was placed in a hot air-circulating type drying
furnace, and the
composition was dried at 80 C for 20 minutes. Then, the coating surface was
pushed
strongly with fingers to examine a sticking degree, whereby the state of the
coating film was
judged.
(5: Neither sticking nor fingerprint mark is observed.
0: Slight sticking and fingerprint marks are observed on the surface.
0: Remarkable sticking and fingerprint marks are observed on the surface.
X: The surface is absolutely sticky.
2) Photosensitivity test
The states of the coating films after UV rays having a wavelength of 365 nm
were irradiated
in exposed doses of 50 mJ/cm2, 100 mJ/cm2 and 150 mJ/cm2 by using the
integrating
photometer produced by Orc Seisakusho Co. and development was carried out with
a
developing solution for 60 seconds at a spray pressure of 2 kg/cm2,
respectively, were
judged visually.
: No change is observed.
0: The surface is slightly changed.
0: The surface is remarkably changed.
X: The coating is fallen.
3) Developability test
Test pieces were obtained by irradiating UV rays having a wavelength of 365 nm
in an
exposed dose of 150 mJ/cm2 by using the integrating photometer produced by Orc
Seisakusho Co. through a photomask, respectively. As comparative samples, test
pieces
irradiated in a dose of 750 mJ/cm2 were used. The states of removing unexposed
portions
after development was carried out with a developing solution for 20 seconds,
40 seconds
and 60 seconds at a spray pressure of 2 kg/cm2, respectively, were judged
visually.
: The test piece is completely developed.
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O: There is a thin undeveloped portion on the surface.
0: There are undeveloped portions entirely on the surface.
X: The test piece is almost not developed.
4) Adhesion property test
Test pieces were obtained by irradiating UV rays having a wavelength of 365 nm
in an
exposed dose of 150 mJ/cm2 by using the integrating photometer produced by Orc
Seisakusho Co. through a photomask, respectively. As comparative samples, test
pieces
irradiated in a dose of 750 mJ/cm2 were used. Test pieces were obtained by
carrying out
development with the respective developing solutions for 60 seconds at a spray
pressure of
2 kg/cm2 and then postcuring under the respective conditions. According to the
test
method of JIS D0202, checkered cross cuts were made, and the states of peeling
after a
peeling test using an adhesive tape were judged visually.
: 100/100, no peeling is observed.
0: 100/100, the cross cut portions are slightly peeled off.
0: 50/100 to 90/100
X: 0/100 to 50/100
5) Pencil hardness test
The hardnesses of the same test pieces as in the adhesion property test (4)
were measured
with a load of 1 kg according to the test method of J!S K5400, respectively.
6) Acid resistance test
The same test pieces as in the adhesion property test (4) were dipped in a 10
% by volume
aqueous sulfuric acid solution at 20 C for 30 minutes and then taken out,
respectively.
The states and adhesion properties of the coating films were judged and
evaluated
synthetically.
: No change is observed.
0: Slight change is observed.
0: Remarkable change is observed.
X: Blistering or swelling and falling of the coating film is/are observed.
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7) Alkali resistance test
A test and evaluation were carried out in the same manner as in the acid
resistance test (6)
except that the 10 % by weight aqueous sulfuric acid solution was replaced by
a 10 % by
weight aqueous sodium hydroxide solution.
8) Solvent resistance test
A test and evaluation were carried out in the same manner as in the acid
resistance test (6)
except that the 10 % by volume aqueous sulfuric acid solution was replaced by
acetone.
9) Plating resistance test
The states of the coating films after the same test pieces as in the adhesion
property test
TM
(4) were plated by using "Autronex Cl" (a plating solution produced by
Cellulex Co. in
U.S.A.) at a liquid temperature of 30 C and a current density of 1 A/dm2 for
9 minutes to
precipitate gold with a thickness of 1.5 pm, respectively, were evaluated in
the same
manner as in the acid resistance test.
10) Soldering resistance test
The states of the coating films after the same test pieces as in the adhesion
property test
(4) were dipped in a soldering bath at 260 C for 10 seconds once and three
times
according to the test method of JIS C6481, respectively, were evaluated in the
same
manner as in the acid resistance test.
11) Strength resistance test
The states of the coating films after the same test pieces as in the adhesion
property test
(4) were dipped in a soldering bath at 260 C for 10 seconds once and three
times
according to the test method of JIS C6481, respectively, were evaluated in the
same
manner as in the acid resistance test. As a flux to be used, K-183 (produced
by Alpha-
Metal Co.) was coated, and the same test was carried out.
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12) Measurement of Insulation Resistance
Using a comb-form test pattern B of IPC-B-25, test pieces were prepared under
the same
conditions as in the Adhesion Property Test (4). According to the testing
method of iPC-
SH-840B, the insulating resistance in the ordinary state and the insulation
resistance under
the following conditions were measured: temperature cycle 25-65 C, relative
humidity 90%,
input direct current voltage 100V, period 7 days.
13) Measurement of Insulating Resistance in Humidified Atmosphere
Using a comb-form test pattern B of IPC-B-25, test pieces were prepared under
the same
conditions as in the Adhesion Property Test (4). Insulation resistance was
measured in a
chamber at a relative temperature of 85 C, a relative humidity of 92% and an
input direct
current voltage of 50V.
14) Measurement of Resolution Property
Test pieces were prepared by irradiating a sample of the present invention
with an
ultraviolet ray having a wavelength of 365 nm at an integrated dose of 150
mJ/cm2 as
measured with an integrating photometer manufactured by Orc Seisakusho Co.,
through
artworks of which line/space ratio ranged from 25 m to 300 m. On the other
hand, control
test pieces were prepared by irradiating comparative samples at a dose of 750
mJ/cm2.
After developing the irradiated test pieces with developing solutions for 60
seconds at a
spray pressure of 2 kg/cm2, the states of the lines remaining unerased after
the
development and the spaces formed by erasion of lines were visually examined
in the
exposed area.
15) Measurement of Water Absorption
Test pieces were prepared by irradiating a sample of the present invention
with an
ultraviolet ray having a wavelength of 365 nm at an integrated dose of 150
mJ/cm2 as
measured with an integrating photometer manufactured by Orc Seisakusho Co.,
through an
art work (in case of control samples, the dose was 750 mJ/cm2), developing the
exposed
sample with a developing solution at a spray pressure of 2 kg/cm2 for 60
seconds, and then
post-curing the deveioped sample at 150 C for 60 minutes. Ceramic board was
used as the
substrate in place of glass epoxy substrate (FR-4), because test pieces
prepared from FR-4
gave much dispersed results. Test pieces were prepared under the same
conditions as in
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the Adhesion Property Test (4) and allowed to stand in an atmosphere having a
temperature of 85 C and a relative humidity of 90% for 120 hours, after which
the change in
water absorption was measured.
16) Measurement of Sensitivity
A sample was irradiated with an ultraviolet ray having a wavelength of 365 nm
at an
integrated dose of 150 mJ/cm2 as measured with an integrating photometer
manufactured
by Orc Seisakusho Co., and developed in a developing solution for 60 seconds
under a
spray pressure of 2 kg/cm2, after which the state of coating film was visually
examined. As
the artwork, a step tablet manufactured by Stouffer Co. was used.
17) Measurement of Odor
Test pieces were prepared by irradiating samples of the present invention with
an ultraviolet
ray having a wavelength of 365 nm through an artwork at an integrated dose of
150 nm/cm2
as measured with an integrating photometer manufactured by Orc Seisakusho Co.,
provided that in case of control test pieces, the dose was 750 mJ/cm2. After
exposure to
light, the film was stripped off, and whether or not an odor was noticed at
this time was
checked. Further, after a post-cure at 150 C for 60 minutes in an oven, the
oven was
opened, and whether or not an odor was noticed at this time was also checked.
18) Boiling Adhesiveness Test
The same test piece as used in the Adhesion Property test (4) was dipped in
boiling water
at 100 C in a glass beaker for one hour, after which the test piece was
withdrawn. Then,
checkers were cut on the test piece according to JIS 0202, a peeling test was
carried out by
the use of a cellophane tape, and the state of peeling was examined visually.
: 100/100, no peeling at all
0: 100/100, slight peeling in cross-cut parts
A: 50/100 - 90/100
x: 0/100 - 50/100
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19) Re-heating Adhesiveness Test
The same test piece as used in the Adhesion Property Test (4) was additionally
cured at
150 C for 3 hours, after which checkers were cut according to JIS 0202,
peeling test was
carried out by the use of cellophane tape, and the state of peeling was
visually examined.
: 100/100, no peeling at all
0: 100/100, slight peeling in cross-cut parts
0: 50/100 - 90/100
x: 0/100 - 50/100
20) Standing Developability Test
A test piece was prepared by subjecting a sample to a preliminary drying at 80
C for 40
minutes, allowing the dried sample to stand under a yellow lamp in a
thermostatted
chamber kept at 23 C for 72 hours, and then irradiating the sample through an
artwork with
an ultraviolet ray having a wavelength of 365 nm at an integrated dose of 150
mJ/cm2 as
measured with an integrating photometer manufactured by Orc Seisakusho Co.,
provided
that Comparative Samples 9-11 were irradiated at a dose of 750 mJ/cmz to make
test
pieces. The test pieces were developed with developing solutions for 60
seconds at a
spray pressure of 2 kg/cm2, after which the state of elimination of the
unexposed area was
visually examined.
O: Completely developed
0: A thin undeveloped film left on surface
0: Undeveloped matter left on the whole
x: Scarcely developed
21) Time-dependent Change
A resist having passed one month after preparation of ink was used. Test
pieces were
prepared by irradiating the resist samples through an artwork with an
ultraviolet ray having a
wavelength of 365 nm at an integrated dose of 150 mJ/cm2 as measured with an
integrating
photometer manufactured by Orc Seisakusho Co., provided that Comparative
samples 9-11
were irradiated at a dose of 750 mJ/cm2 to make test pieces. After development
with a
developing solution for 60 seconds at a spray pressure of 2 kg/cmz, the state
of elimination
of the unexposed area was visually examined.
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00: Completely developed
0: A thin undeveloped film left on surface
A: Undeveloped matter left on the whole
x: Scarcely developed
On the samples thus obtained, dryness to the touch, photosensitivity,
developability (state
of coating film after development), adhesiveness after final cure, hardness of
coating film,
acid resistance, alkali resistance, solvent resistance, plating resistance,
solder resistance,
K183 flux resistance, insulation resistance, insulation resistance in
humidified atmosphere,
resolution property, water absorption rate, sensitivity, odor after exposure
to light, boiling
adhesiveness, re-heating adhesiveness and standing develop-ability were
evaluated. The
results are summarized in Table 1 and Table 2. Comparative Samples 9-11 were
exposed
at a dose of 750 mJ/cm2, because the resist surface of these samples underwent
a change
and properties thereof could not be compared when the dose was 150 mJ/cm2.
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Table 1
Performance Example
1 2 3 4 5 6 7 8 9 10
Dryness to touch 0 0 a 0
Photosensitivity
50 m.T/cm1 0 A 0 0 A 0 A 0 0 A
loo mJ/cm' 0 0 0 0 0 0 0 0 0
150 mJ/cm' OO cJ O 0
Developability
30 seconds A 0 0 0 A
60 seconds 0 0) 0
90 seconds
Adhesiveness
Pencil hardness 6H 6H 6H 6H 6H 6H 6H 6H 6H 6H
Acid resistance 0 0 0 0
Alkali resistance 0 0 0 O
Solvent resistance 0 O
Plating resistance 0 0 O
Solder resistance 0 0 0 0
K183 flux 0 0
resistance
Insulation 7E6 5E5 4E6 8E6 8E6 4E6 8E6 SE6 6E5 4E6
resistance (S2)
Resistance in 8E3 9E6 7E3 8E3 8E3 8E3 8E3 BE3 8E2 7E3
humidified
atmosphere (S2)
Resolution ( m) 25 50 50 25 25 25 25 25 50 50
Water absorption 0.08 0.09 0.20 0.08 0.09 0.18 0.08 0.08 0.09 0.18
M
Sensitivity (steps) 10 9 9 11 10 9 9 11 10 9
Odor after exposure
soiling 0 0
adhesiveness
Re-heating O
adhesiveness
Standing 0 0 0 0
developability
Time-dependent
change
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Table 2
Performance Comparative Example
1 2 3 4 5 6 7 8 9 10 11 12
Dryness to touch O 0 0 0 0 0 A OO
Photosensitivity
50 mi/cm' 0 0 0 A A A 0 A x x x 0
100 m.7/cni O 0 0 0 0 0 0 x x x 0
150 mJ/cm' A x x
Developability
30 seconds 0 0 A A A A x A
60 seconds O 0 0) 0
90 seconds 0
Adhesiveness A t~ A
Pencil hardness 6H 6H 6H 6H 6H 6H 6H 6H 6H 6H 7H 6H
Acid resistance A A A x A
Alkali resistance A 0 A A A
Solvent resistance A 0 0 0
Plating resistance A 0 A x A
Solder resistance 0 0 0 0
K183 flux O 0 a 0 x x x 0
resistance
Insulation 3E7 3E7 8E6 6E5 5E7 6E7 4E7 6E7 3E6 5E5 4E4 7E6
resistance (i2)
Resistance in 9E3 9E3 8E3 9E2 8E3 5E3 9E3 5E3 4E2 5E1 2E1 8E3
humidified
atmosphere (S2)
Resolution ( m) 25 25 75 50 75 100 25 100 100 150 200 25
Water absorption 0.05 0.06 0.05 0.10 0.10 0.07 0.05 0.08 0.5 1.0 2.0 0.08
(%)
Sensitivity (steps) 10 10 10 9 9 8 11 8 5 3 3 10
Odor after exposure x x 0 x
Boiling x x x X x x X X x x X X
adhesiveness
Re-heating x x x x x x x x A A A x
adhesiveness
Standing x x x x x x x x 0 A x a
developability
Time-dependent x x x x x x x x 0 0 0
change
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In the above Tables 1 and 2, El to 7 of insulation resistance and resistance
under
humidification each represent a multiplier portion of a resistance value. That
is, El, E2, E3,
E4, E5, E6 and E7 represent x 107, x 108, x 109, x 1010, x 1011, x 1012 and x
1013,
respectively. For example, 2E3 represents 2 x 109 U. Odor after exposure means
that
odor is generated when a film is peeled off after exposure.
The photopolymerizable thermosetting resin composition of the present
invention is
outstandingly excellent in the general properties required of a solder resist,
such as coating
characteristics, drying characteristics, tackiness, photo-setting property,
developability,
thermosetting property, pot life, shelf life, solder resistance, solvent
resistance, chemical
resistance, adhesion property, electrical insulating property, resistance to
electrolytic
corrosion, electrical properties in humidified atmosphere, plating resistance,
boiling
adhesiveness, re-heating adhesiveness, standing developability, adhesive
property to
rustproofed substrate, etc. Further, the composition of the present invention
can be
developed with dilute alkali solutions and weakly alkaline solutions and is
odorless, so that
the composition of the invention is excellent from the viewpoint of
environmental protection.
