Note: Descriptions are shown in the official language in which they were submitted.
~A
CfO 8175 t~
205961'
- 1 -
1 Method for Manufacturing an Ink ,let Recording Head
and A Recording Head Manufactured Thereby
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an ink -
jet recording head and a method for manufacturing w
the recording head. More particularly, the invention
relates to a recording head having a discharging
port formation member (herein-after also referred
to as "orifice plate") with discharging ports formed
therein.
Related Background Art
As an example of the ink jet apparatus which
discharges ink from its recording head to perform
a desired recording, there is an ink jet recording
apparatus which utilizes thermal energy to cause
the state of ink to be changed and discharges ink
by the pressure which is exerted at that time.
The head used for this apparatus has many
numbers of discharging ports for discharging ink,
ink passes connected to be respective discharging
ports, and a common ink chamber which reservoirs
ink to be supplied to the ink passes.
The recording head is formed by coupling
a plate member called a discharging port plate with
the discharging ports formed therein and the head
2~~~61~
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1 main body in which the ink passes are arranged by
positioning each of the ink passes and each of the
discharging ports.
The discharging ports are formed in the
discharging port plate by a perforative press or
perforative etching or by utilizing a photosensitive.
resin.
However, it is quite difficult to enhance
the precision with which the discharging ports and
ink passes are positioned, and as they are coupled
for the mounting, it is also difficult to improve
the system reliability.
Accordingly, by integrating a grooved
ceiling plate which constitutes the ink passes and
the discharging port plate; an integrated member
of the grooved ceiling plate and charging port plate
is proposed to eliminate the complicated positioning
of the ink passes and discharging ports.
Because of this integration of the discharging
port plate and the grooved ceiling plate, the
discharging port formation method hitherto adopted
can no longer be employed. Therefore, a method
for forming the discharging ports by utilizing a
laser light is proposed by the applicant hereof.
With such a method proposed anew, it is possible
to produce all the discharging ports uniformly just
by a one-time laser irradiation. Moreover, there
~o~~sl7
- 3 -
1 is no need of the complicated positioning. Thus,
with this method, the manufacturing process becomes
easier and more suitable for a large scale production.
On the other hand, the surface of the discharging
port plate should desirably be provided with ink
repellency against the discharging ink. In
other words, the discharged ink adheres to the
circumference of the discharging ports and remains
solidified thereon or the discharging orientation
of the discharged ink is deviated due to the aggregated
ink around the discharging ports. A problem of the
kind must be solved far an improved operation, thus
necessitating the design of the ink repellency on
the plate surface.
Therefore, the surface of the discharging
port plate is formed with a water repellent material
so that on the discharging port formation plane
or at least around the discharging ports, the water
repellency is provided. In other words, a water
repellent resin is coated over the orifice plate.
Then, the resin coating is hardend by a photo ,
or thermal treatment to form a water repellent
layer on the discharging port formation plane.
Also, depending on the material to be used, a material
layer is formed by evaporating by a thermal treatment
the solvent which dissolves the particular material
or the dispersion medium which disperses it to produce
2fl~96~.7
- 4 -
1 the water repellent layer on the face plane. In
such a case of thermal treatment, heating is given
at temperatures higher than the glass transition
point Tg or fusion point Tmp. In some cases, the
structure is arranged so that the discharging port
formation member itself is produced by a material -
having a water repellency. -
This water repellence treatment is performed
as a preperatory process before the laser perforation
to be given because there is a possibility that if
the perforation process is given after this water
repellence treatment, the water repellent agent
used for the treatment is allowed to get into the
discharging ports thus formed and clog them or change
the diameter of the discharging ports.
Now, in this respect, there have been many
proposals made more than ever, for example, in
Japanese Patent Application Laid-Open No. 56-89569,
Japanese Patent Application Laid-Open No. 62-55154,
Japanese Patent Application Laid-Open No. 2-153744,
and others to solve the above-mentioned problem
by forming an ink repellent layer 20 at least along
the circumferential portion of the orifice 14 by
giving the so-called water repellence treatment.
For the water repellent agents used for this water
.. -.
repellence treatment, silicon polymer or oligomer,
or further, fluorine polymer or oligomer or many
2~05~61'~
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1 others can be named.
The water repellence treatment layer 20
to be formed for the ink jet recording head should
be not only effective enough in the water repellency,
but also good enough in the durability of the water
repellence treatment layer itself when a usual ink
jet recording is performed, Otherwise, it cannot
be employed in practice. Hereunder, the description
will be made of its durability.
When the ink jet recording method is applied,
the circumferential portion of the orifice is always
in contact with the recording liquid even if the
water repellence treatment is given to the circum-
ferential portion of the orifice. Accordingly,
the orifice surface is generally wiped by an abosobent
such as polyurethane foam to absorb the ink which
has adhered thereto as a normal recovery operation.
Therefore, the water repellence treatment layer
is required to have an abrasion resistance and other
properties good enough to maintain its adhesiveness
even if rubbed by the abosobent or not allow the
layer to be damaged thereby. If this resistivity
is not sufficient, the water repellence treatment
layer is gradually ripped or dropped off to loose
its water repelling effect while the head is in
use although it works properly in the initial stage.
As a result, a stable discharging printing can no
2~~~~~~
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1 longer be expected.
Meanwhile, however, if the rigidity of the
water repellence treatment layer is extremely high
and the adhesiveness to the circumferential portion
of the orifice is low, the ripping is caused to
occur at the interface of the water repellence treat~ent
layer and the orifice circumferential portion. ..
For the durability thus required for the
ink jet recording head, the water repellence treatment
layers formed by the conventional water repellent
agents have not been effective enough in some cases.
Moreover, in such a case where the members
surrounding the orificies are made of different
materials, it is necessary to prepare a water repellence
treatment layer which has an excellent adhesiveness
to any one of such different materials. In this
particular point, the water repellence treatment
layers formed by the conventional water repellent
agents are found to be unsatisfactory in some cases.
For example, there has been proposed a water
repellence treatment layer which is provided by
a surface 03(Ozone) treatment process as disclosed
in Japanese Patent Application Laid-Open No. 61-141565.
However, there is still a room for improvement with
respect to its durability against wiping because
the coupling between the 03 treatment layer and
the water repellence treatment layer can hardly be
2D~~6~7
_,_
1 good enough.
Also, in Japanese Patent Application Laid-Open No.
61-291148, there is disclosed a water repellence
treatment layer for which a fluorine coating is
given after the treatment by a silane coupling agent.
With this, however, the silane coupling agent is
not strongly coupled to the surface of the processed
component and the durability against wiping is still
insufficient.
Tt is an object of the present invention
to provide a manufacturing method for an ink jet
recording head capable of maintaining a desirable
ink discharging condition for an excellent printing
quality by attaining a water repellency having an
excellent durability against wiping as well as
sufficient water repellent maintainability over
a long period of time, and a head manufactured by
such a method.
Now, the machining of the discharging ports
by laser is performed in such a way that a laser
beam is irradiated onto the orifice plate haying
the water repellency over its discharging port plane
by the above-mentioned treatment, and then the
discharging ports are formed. However, it is found
in reviewing the manufacturing method for the ink
jet recording head that when the discharging ports
are formed on the orifice surface by the application
2o~~s~~
_$_
1 of the laser beam, there occurs a phenomenon that
a by-product due to the orifice machining adheres
to the vicinity of the discharging ports.
In other words, when the laser beam is
irradiated to remove the portion of the material
where the discharging ports are formed, the,materia~..
is dissolved and a part thereof becomes carbon, --
for example, and is deposited on the circumference
of the irradiated portion. Using the ceiling plate
thus prepared, the recording heads are fabricated.
Then, various printing durability tests are conducted
with the results that in some cases, the aforesaid
carbon layer is striped off the ceiling plate to
fly, and eventually, the discharging ports are clogged
by the carbon particles to cause the defective
discharging or disabled discharging, leading to
defective printings.
Further, a part of carbon is also deposited
on the circumferential portion which should become
the discharging ports, and it is observed that when
printings are performed under such circumstances,
the following problem is encountered.
If a deposited substance such as mentioned
above is present on the surface of the discharging
port plate, the physical property of the portion
where such substance is deposited and where it is
not deposited, particularly the wetting condition
- 20596.7
1 with respect to ink, is caused to change. Generally,
the surface of the discharging port plate should
desirably be even so that unnecessary ink puddles
are not present thereon. Despite this consideration,
the ink puddles exist in the circumference of the
discharging ports where the deposit substance is -
present in the recording head processed by the laser --
machining. Because of an ink puddle of the kind,
the flying orientation is not stable liquidly, which
makes it impossible to perform a desirable printing.
Also, if the ink puddles become great, the droplet
discharging becomes disabled to cause the recording
to be discontinued eventually.
SUMMARY OF THE INVENTION
It is an object of the present invention.
to solve the above-mentioned problems and obtain
a highly reliable recording head having no ink
puddles on the surface of the discharging port plate
by removing the carbon layer completely in order
to avoid any clogging up of the discharging. ports
by the carbon particles.
It is another object of the present invention
to provide means to contribute to a further improvement
of the recording quality of a recording head.
In a manufacturing method for an ink jet
head having discharging ports, ink passes connected
~0~0~~7
_ l~ _
1 to the discharging ports, and energy generating
members arranged in the ink passes to generate the
energy which is utilized for discharging ink, it
is still another object of the present invention
to solve the above-mentioned problem and provide a
manufacturing method for a head including the steps
of processes to give a hydrophilic property to the
discharging port formation surface side of the
workpiece which constitures the discharging ports
and to produce a water repellence layer which gives
a water repellency to the upper layer of the
intermediate layer.
Also, in a manufacturing method for an ink
jet head having discharging ports, ink passes connected
to the discharging ports, and energy generating
members arranged in the ink passes to generate the
energy which is utilized for discharging ink, it
is still another object of the present invention
to provide a manufacturing method for a head including
the steps of processes to give an oxidation treatment
to the surface of the discharging port formation
side of the workpiece which constitutes the discharging
ports, to provide an intermediate layer having a
coupling agent containing Si on the oxidized surface
of the discharging port formation side, and to provide
a layer having a polymer containing a fluorine-
containing heterocyclic structure in its principal
- 11 - 205961'
1 chain on the upper layer of the aforesaid intermediate
layer for giving a water -repellency.
Further, in a manufacturing method for an
ink jet head having discharging ports, ink passes
connected to the discharging ports, and energy
generating members arranged in the ink passes to
generate the energy which is utilized for discharging
ink, it is a further object of the present invention
to provide a manufacturing method for a head including
the steps of processes to give an oxidation treatment
to the surface of the discharging port formation
side of the workpiece which constitutes the discharging
ports, to provide an intermediate layer containing
an organometallic compound on the oxidized surface
of the discharging port formation side, and to provide
a layer having a polymer containing a fluorine-
containing heterocyclic structure in its principal
chain on the upper layer of the aforesaid intermediate
layer for giving a water repellency.
2d Furthermore, in a manufacturing method for
an ink jet head having discharging ports, ink~passes
connected to the discharging ports, and energy
generating members arranged in the ink passes to
generate the energy which is utilized for discharging
ink, it is also another object of the present invention
to provide a manufacturing method for a head including
the steps of processes to give an oxidation treatment
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12 -
1 to the surface of the discharging port formation
side of the workpiece which constitutes the discharging
ports, to provide an intermediate layer having an
aluminum resin on the oxidized surface of the
discharging port formation side, and to provide
a layer having a polymer containing a fluorine-
containing thermal plastic resin in its principal w
chain on the upper layer of the aforesaid intermediate
layer for giving a water repellency.
Also, in a manufacturing method for an ink
jet head having discharging parts, ink passes connected
to the discharging ports, and energy generating
members arranged in the ink passes to generate the
energy which is utilized for discharging ink, it
is still another object of the present invention
to provide a manufacturing method for a head including
the steps of processes to give an oxidation treatment
to the surface of the discharging port formation
side of the workpiece which constitutes the discharging
ports, to provide an intermediate layer having an
aluminum hardening resin on the oxidized surface
of the discharging port formation side, and to provide
a layer having a polymer containing a fluorine-
containing thermal plastic resin in its principal
chain on the upper layer of the aforesaid intermediate
layer for giving a water repellency.
With a preparatory process given to a water
2~5~~~.'~
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1 repellent material with respect to the basic member,
the adhesiveness is enhanced to secure a long-time
stability of the water repellency, thereby to attain
a better durability against the cleaning performed
by a blade or the like for the improvement of the
discharging characteristics.
The present invention is designed to solve
the above-mentioned problems present in the
conventional art, and it is an object thereof to
provide a recording head capable of preventing the
degradation of the printing quality and a manufacturing
method therefor in such a manner that subsequent
to having performed an orifice machining by irradiating
a pulse laser onto the orifice plate which has a
water repellence layer on its discharging port surface
or which is itself composed of a water repellent
agent, the by-product having strong hydrophilic
property, which has deposited adhesively on the
vicinity of the orifice, are removed or a predetermined
process is given thereto in order to recover the
water repellency around the orifice, thus preventing
the ink adhesion to the vicinity of the orifice.
To achieve this in an ink jet recording
head having an orifice plate, it is an object of
the present invention to provide a head having a
recovered water repellency in the vicinity of the
orifice by giving the following treatments to the
205617
- 14 -
1 orifice plate which has a water repellence layer
on .its discharging port surface or the orifice plate
which is composed itself of a water repellent material
after having removed the by-product adhesively
deposited on the vicinity of the discharging ports
when they are machined by irradiating a,pulse laser -
or for an orifice plate having the by-product part --
adhesively deposited on the circumference of the
discharging ports when the discharging ports are
machined:
1) heating process treatment
2) cleaning process by ultrasonic
3) cleaning by ultrasonic water flow
4) cleaning by high pressure water flow
5) repeated application and removal of
tapes having adhesive layer
6) plural combinations of the above treatments,
and others
With the structure mentioned above, it is
possible to obtain a recording head capable of
preventing the degradation of the printing quality
by the ink wetting around the discharging ports
as well as of performing a stable printing despite
a change with the passage of time by removing or
changing the state of the hydrophilic part produced
in the vicinity of the discharging ports as a result
of the laser machining.
2~~~6~~
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1 Particularly, when the heating treatment
is given to the by-product generated at the time
of the laser machining, there will result the
enhancement of adhesiveness of the water repellence
layer which is the base of the water repellent by-
product, thus making it possible to obtain an ink -
jet recording head capable of performing stable w
printings notwithstanding a change with the passage
of time.
In the manufacturing method for an ink jet
recording head which can be obtained by machining
perforation to an orifice plate portion of a ceiling
plate formed integrally with a liquid chamber, flow
passes, orifice surface (hereinafter referred to
as orifice plate) so that the flow passes and the
head are conductively connected, the present invention
is designed on the basis of the knowledge that the
prevention of the adhesion of the adhesives is
possible in machining the orifice by the use of
an assist gas blowing together with the irradiation
of laser light when the discharging ports are machined.
The present invention is designed on the
basis of the above-mentioned knowledge, and in the
manufacturing method for an ink jet recording head
provided with a substrate having energy generating
elements for generating energy used for discharging
ink, a ceiling plate having concavities for the
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1 formation of the ink passes in the locations where
the aforesaid energy generating elements are arranged
by coupling it to the aforesaid substrate, and a
discharging port formation member formed discharging
ports thereon for discharging ink by connecting
them conductively with the aforesaid ink passes,
it is an object of the present invention to provide
a manufacturing method for a head which forms the
aforesaid discharging ports by providing processes
to irradiate an excimer laser light and blow a
helium gas for the aforesaid discharging port
formation member.
Also in the manufacturing method for an
ink jet re-recording head provided with a substrate
having energy generating elements for generating
energy used for discharging ink, a ceiling plate
having concavities for the formation of the ink
passes in the locations where the aforesaid energy
generating elements are arranged by coupling it
to the aforesaid substrate, and a discharging port
formation member formed discharging ports thereon
for discharging ink by connecting them conductively
with the aforesaid ink passes, it is an object of
the present invention to provide a manufacturing
method for a head for which the aforesaid discharging
ports are formed by providing the proccesses to
irradiate an excimer laser light and blow an
'\
20~~6~.'~
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1 ionized air.
On the surface of the orifice of the orifice
plate of the ceiling plate thus obtained by the
above-mentioned means, no removals at the time of
machining remain adhesively and there exist no ink
puddles on the orifice plate, hence enabling a desired
discharging of droplets.
In the manufacturing method for an ink jet
recording head provided with a substrate having
energy generating elements for generating energy
used for discharging ink, a ceiling plate having
concavities for the formation of the ink passes
in the locations where the aforesaid energy
generating elements are arranged by coupling it
to the aforesaid substrate, and a discharging port
formation member formed discharging ports thereon
for discharging ink by connecting them conductively
with the aforesaid ink passes, it is an object of
the present invention to provide a manufacturing
20- method for a head including the steps o'f processes
to form a film at least on a part of the integral
member produced by the aforesaid ceiling member
and discharging port formation member, to form the
aforesaid discharging ports by irradiating a laser
Light, and to remove the aforesaid film.
Here, the aforesaid ceiling plate has
concavities for the formation of the aforesaid liquid
2~~~~3 ~
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1 passes, and it is possible to form the aforesaid
discharging ports by irradiating an excimer laser
light from the aforesaid concavity side.
Then, it is possible for the aforesaid part
to include the location where the carbon adheres
by the aforesaid discharging port formation process-
by the laser light.
Also, aforesaid film is made of a material
having a liquid repellency, and the film made of
such a material should be formed at least in the
aforesaid location and in the circumference of the
surface where the aforesaid discharging ports are
arranged. Then, in the aforesaid removal process,
only the film in the aforesaid locations can be
removed selectively.
According to the present invention, the
deposition layer of the carbon generated by the
irradiation of the excimer laser, for example, can
be removed completely by providing the film removal
process. Therefore, there is no dropping off of
the carbon particles in using the recording head,
thereby to make it possible to provide an ink jet
head which satisfies a long-term reliability because
there are no ink discharge and others affected by
such a clogging caused thereby.
Also, it is possible to perform a liquid
repellence treatment process in the circumference
- 19 -
1 of the discharging ports simultaneously.
Also, in the manufacturing method for an
ink jet recording head provided with discharging
ports, ink passes connected conductively to the
aforesaid discharging ports, energy generating
elements arranged in the aforesaid ink passes for
generating energy used for discharging ink, it is w
an object of the present invention to provide a
manufacturing method for a head, comprising:
a process to give a hydrophilic property
to the discharging port formation side of the workpiece
which constitutes the aforesaid discharging ports;
a process to provide an intermediate layer
having a coupling agent containg Si on the plane
to which the aforesaid hydrophilic property is given;
a process to provide a water repellence
layer for givining a water repellency to the ugper
layer of the aforesaid intermediate layer;
a process to form discharging ports by
irradiating a pulse laser beam; and
a process to give a heat treatment to the
by-product deposited adhesively on the circumference
of the discharging ports at the time of the orifice
machining or the orifice plate with the by-product
25, which adhered to the circumference of the discharging
ports thereof.
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1 BRIEF DESCRIFTTON OF THE DRAWINGS
Fig. 1 is a perspective view illustrating
the external appearance of an ink jet recording
head;
Fig. 2 is a schematic view illustrating
the external appearance of a grooved ceiling plate
integrally formed with a discharging port plate
according to the present invention;
Fig. 3 is a view showing the state that
the discharging ports are being formed on the ceiling
plate by a laser beam machining;
Figs. 4A and 4B are a perspective view and a
plan view schematically showing the durability tests
performed for ink jet recording heads of the present
embodimet and a comparison example, respectively;
Fig. 5 is a partial enlargement showing
a state of the by-product adhesion immediately after
a discharging port has been formed on the discharging
part plate by the laser beam machining;
Fig. 6 is a partial enlargement showing
a part of the discharging port plate subsequent
to having completed the by-product removal process;
Fig. 7 is a diagram showing the characteristics
of heating temperatures and times with respect to
a heat treatment apparatus according to the present
invention;
Fig. 8 is a schematic view showing an He
24~~~~.~
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1 gas discharging means provided at the time of laser
beam machining;
Figs. 9A and 9B are cross-sebtional side
views showing the states of the coating layer of
the grooved ceiling plate integrally formed with
the discharging plate before and after a cleaning -
process, respectively;
Fig. 10 is a schematic view showing an
example of the ceiling plate after machining when
its coating layer is formed with a water repellent
agent; and
Fig. 11 is a view schematically showing
an ink jet recording apparatus in,which a recording
head of the present invention can be mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, with conjunction to the
accompanying drawings, the present invention will
be described.
At first, the description will be made of
the schematic structure of an ink jet head to which
the present invention is applicable.
An ink jet recording head shown in Fig.
1 is provided with a recording head main body (not
shown) which is structured by combining a ceiling
plate having concavities (hereinafter referred to
as grooves) constituting ink passes and a common
- 22 -
1 liquid chamber, which is further formed integrally
with an orifice plate 10, with a substrate (herein-
after referred to as heater board) on which electro-
thermal converting elements (hereinafter referred
to as discharging heater) and AI wirings for supplying
electric signals to the discharging heaters are
formed on an Si substrate.
Also, in Fig. 1, a reference numeral 600
designates a sub-ink tank which is arranged adjacent
to the recording head main body. This sub-ink tank
600 and the aforesaid main body are supported by
a cover 300. Further, reference numeral 1,000
designates a cartridge main body and 1;100, a
covering member of the cartridge main body. In
the inside of the cartridge main body, an ink tank
is incorporated to supply ink to the sub-ink tank
600 appropriately.
Fig. 2 is a view schematically showing a
structural example of the grooved ceiling plate
integrally formed with a discharging plate (herein-
after referred simply to as ceiling plate in..some
cases) 7 which constitutes the aforesaid head.
The ceiling plate 7 according to the present
example has ink pass grooves 14 and ink discharging
ports 11 formed on an orifice plate 10 corresponding
to the ink pass grooves in a number as desired (in
Fig. 2, two pieces being shown for simplification),
20596~."~
- 23 -
1 and is structured with a discharging port plate
which is integrally arranged with the ceiling
plate.
Then, in the structural example shown in
5 Fig. 2, the ceiling plate 7 is molded integrally
with the orifice plate 10 simultaneously in a metallic
mold using a resin having an excellent ink resistivity
such as polysulfone, polyether sulfone, polyphenylene
oxide, and polypropylen.
10 Now, the description will be made of a method
for forming the ink pass grooves 14 and orifice
11. For the ink pass grooves, it is possible to
form the liquid pass grooves 14 by a resin which
is formed by a method using a technique to cut the
fine grooves having a pattern opposite to the ink
pass grooves or the like, thus enabling the formation
of the liquid pass grooves 14 on the ceiling plate
7.
The discharging ports on the orifice plate
of the ceiling plate 7 can be formed as given below.
Fig. 3 illustrates a state where the orifice
is being machined by irradiating an excimer laser
light from the ink pass side to the orifice plate
which is formed integrally with the ceiling plate,
25~ in which the same reference signs are given to the
same elements appearing in Fig. 1. In Fig. 3, a
reference numeral 1 designates a laser oscillator
- 24 -
1 for oscillating KrF excimer laser light; 2, a pulse
laser beam having a wavelength of 248 nm or 365 nm
with a pulse width of approximately 15 nsec emitted
from the laser oscillator 1; 3, a synthesized quarts
lens for converging the laser beam 2; and 4, a
projection mask which shields the laser beam 2 with-
a deposition of aluminum and constructs an orifice
pattern with a plurality of holes of 133 um diameter
arranged at pitches of 212 um.
Embodiment 1
Using the laser beam having a wavelength
of 248 nm, a hydrophilic oxidation treatment layer
is produced at least on the circumference of a portion
where the orifice is expected to be formed on the
ceiling plate having the aforesaid orifice plate
by the oxidation using an oxidizing agent or by
cleaning with UV/03 or the like.
Subsequently, this ceiling plate is dipped
in an amino silane coupling agent (for example,
A1110Y - aminopropyl trimetoxylen: Nippon Unika -).
Then, excessive silane coupling agent is removed
in a pure water to form a single molecular layer
of silane coupling agent on the orifice circumference
uniformly.
Then, after an air drying, a water repellence
treatment is given. For the water repellence
treatment agent, there is used a dilution prepared
- 25 -
1 by diluting the solution (5 weight ~) of CTX-805A
(Asahi Glass Inc.) and CTX-105A (Asahi Glass Inc.)
by CT-Solve 100: CT-Solve 180 (boiling point being
100°C and 180°C respectively: this ceiling plate is dipped
by Asahi Glass Inc.) in a ratio of 4 . 1. As to
the density, while it is possible to adopt a range
of 0.01 weight ~ to 5.0 weight ~, particularly,
the range of 0.1 to 0.7 weight ~ is best suited.
As a method for coating the agent to the head, a
brush coating, casting method, or the like can be
adopted. Then, a thermal drying treatment is given
for an hour at 150°C. Subsequently, a laser
perforation is performed to form the discharging
orifice, and a substrate having discharging pressure
generating elements is bonded thereto adhesively.
The head thus fabricated is prepared as sample 1.
As an example of the water repellent agent
used for the present invention, a fluorine-containing
heterocyclic agent can be named. The fluorine-
Containing heterocyclic structure means an organic
substance of five to eight rings containing one
to two heteroatoms in a chemical constitution formula.
The heteroatoms are the atoms other than carbon
(C). More specifically, oxygen (O), nitrogen (N),
sulfur (S), phosphorus (P), and others are used.
Particularly, oxygen (O) is suitably used from the
viewpoint of its chemical stability and safety.
- 26 -
1 Tn the present invention, the fluorine-
containing polymer having the heterocyclic structure
should have a fluorine content ratio of 10 weight
~ or more from the viewpoint of the ink repellency
(contact angle), and it should preferably be 25
weight ~ or more and further preferably be 50 weight
~ or more, w
Also, the ratio of the cyclic structure
in the principal chain should be 10~ or more in
consideration of the strength of an object film
or its solvency to the solvent or from the viewpoint
of its adhesiveness to the substrate or the like,
and it should preferably be 20~ or more and further
preferably be 30$ or more.
In the present invention, it is preferably
to use particularly a noncrystalline polymer among
the fluorine-containing polymers having the heterocyclic
structure. The noncrystalline polymer is excellent
in its film strength, adhesiveness to the substrate,
film uniformity, and the like. Therefore, with
this polymer, the effects of the present invention
can be more prominently displayed.
As the fluorine-containing polymer having
the heterocyclic structure in the principle chain
in the present invention, it is preferable to use
those disclosed in the specification of the U.S.
Patent No. 3,418,302, the specification of the
- 27 -
1 U.S. Patent No. 3,978,030, Japanese Patent Laid-
Open Application No. 63-238111, Japanese Patent Laid-
Open Application No. 63-238115, Japanese Patent Laid-
Open Application No. 1-131214, Japanese Patent Laid-Open
Application No. 1-131215, and others, for example.
Among the polymers having the heterocyclic -
structures mentioned above, those given below are
typical ones. It is to be understood, however,
that the contents of the present invention are not
confined only to those mentioned here.
2~~~1'~
- 28 -
1. 0 _
/ C\s
CF CF
I I
O O
\ /
C F=
/ CFa\
-.- C F C F
I
O O
\ /
CF2 CFa
CF-CF
/ \
O O
\ /
CFi GFa
cFa
/ \
CF CF
I I
O CFa
- 29 -
1
CF--CF
O CFZ
cF~
CFy
/ \
CF CF
I l
O CFZ
\ /
CF~
Futhermore, in order to enhance the
adhesiveness to the substrate or to control the
solubility to Tg and solution, it may be possible
to introduce the following structure into the
principal chain:
R3 R4
C - C
I I
R5 X
2059G1'~
- 30 -
1 (where R3, R4, and R5 are H, F, C1, and Rf (fluorine-
containing alkyl), and X is H, F, C1, Rf3, and Rf4.
However, Rf3 is a fluorine-containing organic
substituent having acid, ester, alcohol, amine,
amide, and other functional group at its terminal
Rf4 is a fluorine-containing alkyl and,fluorint- -
containing ether.) These constructions can be obtained --
by copolymerizing the comonomers given below.
CF2 = CF-O-CF2CF(CF3)-O-CF2CF2S02F,
CF2 = CF-O-CF2CF2CF2COOCH3,
CF2 = CF-CF2CF(CF3)-O-CF2CF2S02F
Embodiment 2
In the embodiment 1, a head fabricated without
cleaning in a pure water is prepared as sample 2.
Embodiment 3
In the embodiment 1, a head fabricated with
the wavelength of laser being 365 nm is prepared
as sample 3 .
Comparison example 1
An ink jet recording head is fabricated
in the same manner as the first embodiment except
that no treatment with silane coupling agent is
performed. A head of the kind is prepared as sample
4.
2~~~6~'~
- 31 -
1 Evaluation of durability
Friction durability tests are conducted
as given below on the samples 1 through 4 of the
ink jet recording heads fabricated in the embodiments
1, 2, and 3, and the comparison example 1.
Figs. 4A and 4B are a perspective view and a_
plan view to illustrate respectively such a friction
durability testing briefly.
As shown in Figs. 4A and 4B, when a silicone
rubber plate 21 structured in the same manner as
a cleaning blade is caused to rotate by the rotation
of a member 22, the surface treatment layer 20 of
the ink jet recording head 1 is slidably rubbed
by the silicone rubber plate 21 under a pressure
of approximately lOg/cm2. Also, in order to condition
the slidable rubbing as close as to the actual state
in use, the ink droplets 25 of a water color ink
are sprayed from an ink spraying device 24 over
the portion slidably rubbed.
Using this apparatus, the durability test
is conducted for 1,000 to 20,000 times with the
frequency of the ink spraying being once in ten
seconds. During this test, the head is removed
each at 1,000, 5,000, 10,000, and 20,000 times of
the slidable rubbings, and used for printing for
the observation. The results are stated in Table
1. In this respect, each of the marks appearing
~0~J61'~
- 32 -
1 in the Table 1 indicates the printing condition
I which has been obtained, and a mark o shows desirable
printing condition, Q , ordinary printing condition,
and X, inferior printing condition, respectively.
The desirable or inferior printing condition is
determined both by measuring the amount of the .
deviated dots from the impact points and an
organoleptic test by eye-sight. The averaged evaluation
for each of the samples tested is stated in Table 1. w
Table 1
Sample Sample Sample Sample 4
1 2 3
1,000 Q ~ O o 0
5.000 0 0 o X
10,000 0 0 0 -
20,000 0 ~ o -
o... desirable (~ ... ordinary X ... inferior
As clear from the results shown in the Table 1,
the recording head (Sample 4) fabricated by the
comparison example 1 shows an inferior printing
condition at 5,000 slidable rubbings. This is caused
by the separation of the surface treatment layer.
As compared with the sample 4, the heads (Samples
1, 2, and 3) fabricated by the embodiments 1, 2,
~~5~f~~.'~
- 33 -
1 and 3 show the desirable or ordinary printing conditions
until 20,000 slidable rubbings. Particularly, as a
result of the comparison among them, it is observed
that the quality of the samples 1 and 3 is stable
after 20,000 slidable rubbings because of the water
treatment given to each of them.
In the present invention, it may be possible .-
to attain a strong bonding state between the substrate
and water repellent agent by providing a layer containing
not only Si coupling agent as an intermediate layer
but an organometallic compound, amine resin, amine
hardening resin also as the intermediate layer.
On the grooved ceiling plate 7 formed integrally
with the discharging port plate thus fabricated, the
by-product generated by the laser perforation adheres
to the circumference of the discharging ports. Now,
hereunder, various methods for removing this by-product
or removing any adverse effects produced thereby will
be disclosed.
Embodiment 4 - Heating treatment method -
The grooved ceiling plate integrally..formed
with the discharging port plate, for which a water
repellence treatment has been processed by the method
shown in the embodiment 3, is mounted on a laser
perforation apparatus shown in Fig. 3 (manufactured
by L'Monix) to from discharging ports by irradiating
a laser light of 365 nm (for two seconds) with 200
~05~f 17
1 pulses per second.
There is shown in Fig. 5 a partial enlargement
of the discharging port plate immediately after the
formation of the discharging ports by the irradiation
of the laser light. In Fig. 5, a reference numeral
2 designates an excimer laser beam; 10, an orifice
plate; 6, a water repellence layer; 11, the dischanging ..
opening formed by the discharging port machining device
shown in Fig. 2; and 8, the by-product generated
bY the orifice machining, which has adhered to the
vicinity of the discharging port. In the present
embodiment, the incidence of the laser beam 2 is given
to form the discharging opening 11 from the plane
of the discharging port plate 10 where no water
repellence layer has been provided.
The discharging plate with the adhesive
deposition of the by-product on the vicinity of its
discharging openings due to a discharging port machining
of the kind is processed by heating under the conditions
given below in order to obtain an optimal value of
the heating treatment process.
The heating device used is a clean oven (Model
No. Yamato DE-42). The heating temperatures are set
at 90°C t 2°C, 120°C~2°C, 150°C~2°C,
and 170°C~2°C.
The heating times are set for 0.5 hour, 1.0 hour,
2.0 hours, and 4.0 hours. After the treatment processes
given in these combinations, the grooved ceiling plates
~~~~~'~'l
- 35 -
1 integrally formed with the discharging port plate,
which have been treated by the heating process, are
immersed in an ink of 60°C (for an extremely short
period of time or only dropping of ink droplets
(represented as initial), 40 hours, and 100 hours)
and then the ink wetting conditions around the
discharging ports are observed by a metallurgical ..
microscope. Here, seven samples are observed for
each. The results are stated in Table 2 given below.
15
25
20~9G1?
- 36 -
1 -
~ ~ d' N er M
G"'~ M lf7
N
r ~ M M
O +~
O
w
O
U7 ~' ~ O O p O
~~I
N
o o O O
~ X
~
U ~ .1~ ~ ~-I N N
o rl
o wo
O
u, x ~ M vo u~ ~r
~r
a
0 0 0
U .rl
o .~.~ a o O O O
o .~ ..
~o G
H l~ l~ l~ n
~
N w
,
O O O O
O
~
~ o O O O
.-~
N
x ~p ~ M M
N S-1
1.1
U ~ N ~ ,",~ O ~i, d'
.t;
o +.~
o -~ w
o
N ~ O O O O O
d'
N .a x
0 0 0 0
~ .~,
.'.,
~ U +t ~ M ~-I o r-1
o -.i
ro H o
N~ X
~ Q
X
I I
~
w ~ o
x
w
V ~ ,~p O O o
O C
w0 t-c O O O O O
N ,f; .~', ~" .C:
S.1
~
p, w n o o O
.
,~ ~ .
~
+~ c o ~ N
a~
,~ ...i
~,
~ ro
~o~os~~
- 37 -
1 In this respect, the mark ~ in the Table
2 indicates that there are no wetting phenomenon
around the discharging ports; Q , slight wetting
around the discharging ports; and X, conspicuous
wetting around the discharging ports, respectively.
The numeral under each mark indicates the number of -
the samples showing the wetting phenomenon of the
corresponding mark.
Here, in the heating treatment process at
170°C~2°C, the ink wetting phenomenon is almost equal
to or better than the results obtained in observing
those processed at 150°C~2°C. However, there are
some samples which have been deformed because the
grooved ceiling plate integrally formed with the
discharging plate is made of a polysulfone whose
fusing point is 180°C.
Accordingly, an experiment to ascertain the
upper limit of the heating temperature is conducted
under the heating condition given to 170°C by raising
the temperatures from 150°C by 5°C each. Then, until
165°C, the samples have been obtained without -any
essential problems.
It is therefore preferable to set the heating
treatment temperature between 120°C or more and 165°C
or less or more preferably between 140°C or more and
165°C or less.
In the present embodiment, 150°C can be
- 38 -
1 selected as a most preferable temperature which produces
no adverse effect on polysulfone. Here, this temperature
depends on the material of the head and water repellent
agent to be used. Hence, 'the heating temperature
is arbitrarily selective by the materials to be used.
For the heating time, however, a sufficient -
effect is obtainable if only it is more than one hour.
The upper limit of the heating hour in the present
embodiment is four hours, which is considered long
enough, but it may be possible to make it longer.
Here, in the actual manufacturing process,
there are the rising time and falling time for the
temperature of the heating oven. As a result, the
grooved ceiling plate formed integrally'with the
discharging port plate should be left in the oven
for eight hours to twelve hours. However, the
temperature control must be carried out so that the
ceiling plate is held for more than one hour at least
at the optimal temperature of 150°C.
In other words, in the actual manufacturing
process, the oven which presents a temperature curve
as shown in Fig. 7 is adopted in condition that the
heating temperature is set at 150°C~2°C for the heating
time being one hour (at H in Fig. 7) with the oven
temperature being at 153°C, and during the heating,
the N2 flow rate is set for 20 1/min. In this respect,
the material should be~removed from the oven after
20~9~1'~
- 39 -
1 the temperature is lowered to 80°C or less.
In a heating treatment process such as the
present embodiment, the water repellent agent is affected
by the added heat to become fluid. Thus, it runs
out to cover the by-product generated by the laser
perforation, and eventually, the plate surface is _
entirely covered by the water repellent agent. In
this way, it is possible to produce the grooved ceiling
plate formed integrally with the discharging plate
having a desirable water repellency.
Embodiment 5
Now, an example of a cleaning by ultrasonic
in a water will be disclosed.
As described earlier, subsequent to the
machining of the discharging ports by the discharging
port machining device, a ultrasonic cleaning is given
to the orifice plate having the adhesively adhering
by-product on the circumference of the discharging
ports. For the discharging port plate 10, a polyether
sulfone film is used. Also, as the water repellent
agent, KP801 (Product name: Shinetsu Kagaku Inc.)
is used to coat the discharging port plate 10. Then,
the heating treatment process is given at 150°C for
one hour to form the water repellence layer 6. To
the discharging port plate 10 with the water repellence
layer 6 thus formed, a KrF excimer later beam is
irradiated from the plane opposite to the plane Where
- 40 -
1 the water repellence layer 6 has been formed. Hence,
the discharging ports 11 are formed. Then, the ultrasonic
cleaning is given in a water to the discharging port
plate 10 with the discharging ports 11 thus formed.
In this way, the by-product 8 generated at the time
of orifice machining is almost removed.
The orifice is machined as above. Then, the
ink jet recording head is fabricated with the orifice
plate, the by-product deposited on which has been
removed, and is mounted on a printer for the observation
of the discharging droplets as well as for the recording
onto a recording sheet. As a result, it is found
that the discharging orientation of the flying droplets
is stable as compared with the ink jet recording head
fabricated with an orifice plate which is not given
any ultrasonic cleaning, and that the resultant printing
is also desirable.
Embodiment 6
Subsequently, there will be disclosed an example
of a recording head fabricated in the same manner
as the embodiment 5 with the exception of the..use
of an XeCl excimer laser light as the laser light
source of the discharging machining apparatus. After
the discharging port plate has been machined as described
earlier, the discharging port plate having the by-
product adfiesively deposited on the circumference
of the discharging ports is cleaned by a ultrasonic
- 41 -
1 water flow. For the discharging port plate 10, a
polyimide film is used. Also, for the water repellent
agent, KP801 (Product name: Shinetsu Kagaku Inc.)
is used to coat the discharging port plate 10. Then,
the heating treatment process is given at 150°C for
one hour to form the water repellence layer 6. To -
the discharging port plate 10 with the water repellence
layer 6 thus formed, an XeCl excimer laser beam is
irradiated from the plane opposite to the plane where
the water repellence layer 6 has been formed. Hence,
the discharging ports 11 are formed. Then, the cleaning
by a ultrasonic water flow using a pure water is given
to the discharging port plate 10 with the discharging
ports 11 thus formed. In this way, the by-product
g generated at the time of orifice machining is almost
removed.
The discharging ports are machined as above
Then, the ink jet recording head is fabricated with
the orifice plate, the by-product deposited on which
has been removed, and is mounted on a printer for
the observation of the discharging droplets as well
as for the recording onto a recording sheet. As a
result, it is found that the discharging orientation
of the flying droplets is stable as compared with
the ink jet recording head fabricated with a discharging
port plate which is not given any cleaning by the
ultrasonic water flow, and that the resultant printing
is also desirable.
20~~G17
1 Embodiment 7
Now, hereunder, another embodiment will be
described.
After the aforesaid machining by the
discharging port machining device, the discharging
port plate having the by-product adhesively
deposited on the circumference of the discharging w
ports is cleaned by a high pressure water flow.
For the discharging port plate 10, a
polyether sulfone film is used. Also, for the
water repellent agent, Si-top (Product name: Asahi
Glass Inc.) is used to coat the discharging port
plate 10. Then, the heating treatment process is
given at 120°C for one hour to form the water
repellence layer 6. To the discharging port plate
10 with the water repellence layer 6 thus formed,
a KrF excimer laser beam is irradiated from the
plane opposite to the plane where the water
repellence layer 6 has been formed. Hence, the
discharging ports 11 are formed. Then, to the
discharging ports 11 thus formed on the discharging
port plate 10, a high pressure water flow produced
by discharging a pure water continuously under a
pressure of 200 kgf/cm2 from a sapphier nozzle of
50 microns is applied in the direction of the
discharging ports. Then, as shown in Fig. 6,
although the by-product 8 generated at the time
~~~~6~~
- 43 -
1 of orifice machining in a location where the high
pressure water flow has not reached cannot be
removed sufficiently, the by-produce due to the
laser machining which has adhered to the
circumference of the discharging ports of the
discharging port plate is removed. -
The discharging ports are machined as above.
Then, the ink jet recording head is fabricated with
the orifice plate, the by-product deposited on
which has been removed, and is mounted on a printer
for the observation of the discharging droplets as
well as for the recording onto a recording sheet.
As a result, it is found that the discharging
orientation of the flying droplets is stable as
compared with the ink jet recording head fabricated
with a discharging port plate which is not given
any cleaning by the high pressure water flow, and
that the resultant printing is also desirable.
Embodiment 8
Now, hereunder, still another embodiment will
be described.
After the aforesaid machining by the
discharging port machining device, the application
and removal of cellophane tapes are repeated five
times against the discharging port plate having the
by-product adhesively deposited on the
circumference of the discharging ports. For the
- 44 -
1 discharging part plate 10, a polyimide film is
used. Also, for the water repellent agent, KP801
(Product name: Shinetsu Kagaku Inc.) is used to
coat the discharging port plate 10. Then, the
heating treatment process is given at 150°C for one
hour to form the water repellence layer 6. To the-
discharging port plate 10 with the water repellence
layer 6 thus formed, an XeCl excimer laser beam is
irradiated from the plane opposite to the plane
where the water repellence layer 6 has been formed.
Hence, the discharging ports 11 are formed. Then,
the application and removal of the cellophane tapes
repeated five times each against both planes of the
discharging port plate 10 having the office 11 thus
formed. In this way, the by-product generated at
the time of discharging port machining is removed.
The discharging ports are machined as above.
Then, the ink jet recording head is fabricated with
the orifice plate, the by-product deposited on
which has been removed, and is mounted on a printer
for the observation of the discharging droplets as
well as for the recording onto a recording sheet.
As a result, it~is found that the discharging
orientation of the flying droplets is stable as
compared with the ink jet recording head fabricated
with a discharging port plate for which no
application and removal of the cellophane tapes are
- 45 -
1 conducted, and that the resultant printing is also
desirable.
Embodiment 9
As shown in Fig. 8, an excimer laser light is
irradiated from a laser device to the position
where the orifice should be formed from the ink
pass side of the orifice plate. The resin is thus
removed and evaporated so that the orifice 11 is
produced. When this excimer laser light is
irradiated, helium is blown as an assist gas for
machining. In the present implementation, a helium
gas 50 of 99.9999$ purity is continuously blown
from a helium blowing nozzle 51 as shown in Fig. 8
during the machining by the laser irradiation.
Z5 To the ceiling plate which is being machined
with the blowing helium gas in such a manner as
this, no removals by the laser light adhere to the
surface of the orifice plate,
Embodiment 10
Subsequently, the description will be made of
a second embodiment according to the present
invention.
In the present embodiment, too, the structure
of the head and the devices to be used for forming
2S the discharging ports are the same.
In the present embodiment, the blowing of the
helium gas is conducted in the direction toward the
2a5961'~
- 46 -
1 laser light with the ceiling and orifice plates
being sandwiched therebetween. When the helium gas
is blown in this direction, the helium gas is
allowed to reach the surface of the orifice plate
mare efficiently. As a result, it becomes more
difficult for the removals of the machining to
adhere to the surface thereof. Also, in this
method, the effect of the helium gas blowing is the
same if it is blown just before the portion of the
discharging ports to be formed is penetrated on the
way of the machining by the laser light
irradiation.
Embodiment 11
Now, as an embodiment according to the
present invention, the description will be made of
a method using an ionized air.
In the present embodiment, too, the structure
of the head and the device used for forming the
discharging ports are the same.
In the present embodiment, the ionized air
is produced by a device which ionizes air. .Such
a device is installed in the same manner as in the
first and second embodiments. When the device is
actuated, the ionized air is blown from the blowing
nozzle. While this air is being blown, the excimer
later light is irradiated onto the orifice plate
of the ceiling plate to perform the discharging
20596.'7
- 47 -
1 port formation machining. In the present
embodiment, the removals at the time of machining
do not adhere to the surface of the orifice plate,
either, as in the case of the previous embodiments.
Comparison example
The performance of the ink jet recording -
head obtained from the example embodying the --
present invention is examined and compared with
those of the conventional head. The results are
stated in Table 3 and Table 4.
Table 3
State of orifice
plate at the time
of recording
Conventional head large ink puddle observed
Embodiment 9 no ink puddle
Embodiment 10 no ink puddle
Embodiment 11 almost no ink puddle
Table 4
_-_____..___......._.........._.........._._......_...___....___.~
Irregularity in Recording result
flying direction
___.___._._..._.______ ___..__.-___-.________._ _
Conventional head _+10° fair
Embodiment 9 _+ 2° ~ good
Embodiment 10 ~ _+ 1° - Particularly
good
Embodiment 11 + 4° good
Embodiment 12
The present embodiment is such that during
the aforesaid fabricating process, a protection
2059617
- 48 -
1 coating layer is produced before the performance
of the laser perforation, and that the protection
coating layer is removed after the laser
perforation machining. Hereunder, the formation
process of the ceiling plate formed integrally with
the discharging port plate will be described
sequentially.
I. At first, regarding the ink pass grooves, resin
(polysulfone, polyether sulfone, polyphenylene
oxide, polypropylene, or the like) is formed by a
metallic mold prepared by a method of cutting or the
like to produce a fine groove pattern opposite to
the ink pass grooves, whereby to form the ink pass
grooves 14 on the ceiling plate material.
II. Then, the ceiling plate material having the
ink pass grooves 14 thus produced is immersed in
an organic solvent, for example, to give a coating
of the organic solvent thereon. For this organic
solvent, it is fundamentally possible to use any
type of organic solvents as desired if only it can
be removed in the following fabrication process.
In the present example, since the material of the
ceiling plate is resin, there is a possibility that
if an organic solvent is used in the removal
process, a solvent cracking or the like occurs.
Therefore, it is preferable to use a coating agent
which can be removed by a removal agent, water or
2~5~617
- 49 -
1 the like.
III. Subsequently, an excimer laser light is
irradiated from the laser device to the position
of the discharging ports to be formed from the
ink pass side of the orifice plate 10 to remove
locally and evaporate the resin of the ceiling -
plate for the formation of the discharging ports w
11.
As clear from Fig. 8, and Fig. 9, the excimer
laser light 2 is irradiated onto the orifice plate
10 from the ink pass side 14 through the aforesaid
mask 4. Also, the excimer laser light 2 is
converted in relation to the optical axis 13 at an
angle of one side A1 = 2° and is irradiated in the
direction perpendicular to the orifice plate 10
with an inclination of the optical axis 13 at an
angle of A2 = 10°.
By irradiating the laser light from the ink
pass side in such a manner as this, the cross-
sectional area of the orifice of a tapering shape
presents a shape which is gradually reduced in the
discharging direction.
Now, the description will be made of the
excimer laser light to be used for this example
embodying the present invention.
The excimer laser is a laser capable of
oscillating ultraviolet light and has a high
2~5~617
- 50 -
1 intensity, an excellent mon ochromaticity,
directivity, capability of short pulse oscillation,
capability of making energy density extremely great
by converging a lens, and other advantages.
The excimer laser oscillator is a device
capable of oscillating a short pulse (15 to 35 ns)-
ultraviolet light by the discharge excitation of a w
rare gas and halogen mixture, and Kr-F, Xe-C1, Ar-F
lasers are often employed therefor. The number of
these oscillating energies is 100 mJ/pulse and the
pulse repetition frequency is 30 to 1,000 Hz.
When a high luminance short pulse ultraviolet
light such as this excimer laser light is
irradiated onto the surface of a polymer resin, an
ablative photodecomposition (APD) process is
generated so that the irradiated portion is
instantaneously dissolved and splashed with the
accompanying plasma emission and impulsive sound.
Hence, with this process, the polymer resin can be
machined.
When comparing the machining precision by an
excimer laser of the kind and the one by some other
lasers in such a case that a laser as an excimer
laser and other YAG laser and C02 laser are
irradiated onto a polyimide (PI) film, it is found
that a clear perforation is obtainable by a KrF
laser because the light absorbing wavelength of PI
20~~617
- 51 -
1 is UV region whereas with the YAG laser which is
not in the UV region, the edge of the perforation
becomes rough although it is still obtainable, and
with the C02 laser which is infrared, a crater is
generated around the perforation formed.
Also, an SUS and other metals, opaque -
ceramics, Si, and others are not affected by an --
irradiation of the excimer laser in the aerial
atmosphere. Therefore, these can be used as a mask
material for the excimer laser machining.
IV. Subsequently, the ceiling plate with the
discharging ports thus provided is cleaned using an
appropriate solvent and others in order to remove
the carbon layer deposited on the coating layer.
Both of the carbon layer and coating layer are
removed together as if they are lifted off.
In Fig. 9A, there is schematically shown an
adhesive state of the carbon layer at the time of
the excimer laser machining subsequent to the
coating of an organic solvent. In Fig. 9A, a
reference numeral 16 designates the coating..layer
of an organic solvent and 17, the carbon layer
deposited thereon. In this respect, there is a
tendency that the carbon layer is most thickly
z5 deposited on the circumference of the discharging
ports 11 of the orifice plate 10 where the excimer
laser light is directly irradiated, and that the
~05~6~."~
- 52 -
1 deposition becomes thinner as it is further away
therefrom.
After this, an appropriate cleaning treatment
is given. Then, although the details will be
described later, it is possible to obtain a ceiling
plate 5 without any carbon layer 17 as illustrated-
in Fig. 9B.
Using the grooved ceiling plate formed
integrally with the discharging port plate
fabricated as described above, it is possible to
obtain a recording head main body in a cartridge
mode as shown in Fig. 1, and further, using this,
it is possible to construct an ink jet printer as
shown in Fig . 11.
Here, in Fig. 11, a reference numeral 180
designates a cartridge shown in Fig. 1. This
cartridge 180 is fixed on the carriage 151 by a
pressure member 181 so as to be shuttled in the
longitudinal direction along a shaft 121. Also,
the positioning of the carriage 151 is performed by
the nibs provided in a cover 1,300 and dowels or
the like arranged on the carriage 1 side. Also,
the electrical connection can be made by coupling
a connector of the carriage 151 to a connecting
pad provided on a wiring board.
The discharged ink from the recording head
reaches a recording medium 118, the recording
- 53 -
1 surface of which is controlled by a platen 119 with
a fine space provided between the platen and
recording head, to form an image on the recording
medium 118.
To the recording head, discharging signals
corresponding to image data are supplied from an -
appropriate data supply source through a cable 116
and terminal connected therewith. One or plural
cartridges 180 (two in Fig. 11) can be provided
in accordance with the color or colors of ink to be
used and the like.
Now, hereunder, the description will be made
of the embodiments in which the adhesive states of
the carbon layer 17 of the ceiling plate 5 formed
in accordance with various coating processes (the
above-mentioned (II)) and removal processes (the
above-mentioned (IV)) are observed and at the same
time, the printing states of the recording head
fabricated using such a ceiling plate are
evaluated.
Embodiment 13
As a coating agent in the process (II), a
positive type liquid resist used for the so-called
photolithography (for example, a 5$ solution of
OFPR-800 manufactured by Tokyo Ohka Kogyo Inc.)
is employed, and in such a solution, the ceiling
plate material is immersed and dried naturally for
2059617
- 54 -
1 30 minutes after being lifted therefrom. Here,
the ceiling plate member is formed in the aforesaid
process (I) and polysulfone is used for its
material.
Then, in the process (III), the discharging
ports are machined and in the process (IV), the
discharging port plate is immersed in a development
(for example, NMD3: Tokyo Ohka Kogyo Inc.) for
a five-minute ultrasonic cleaning.
Embodiment 14
As a coating agent in the process (II), a
positive type liquid resist used for the so-called
photolithography (for example, a 5$ solution of OMR
83 manufactured by Tokyo Ohka Kogyo Inc.) is
employed as in the case of the embodiment 13, and
in such a solution, the ceiling plate material is
immersed and dried naturally for 30 minutes after
being lifted therefrom. In this respect,
polypropylene is used for its material.
Then, in the process (III), the discharging
ports are machined and in the process (IV),,.the
discharging port plate is immersed in xylene for
a five-minute ultrasonic cleaning.
Embodiment 15
As a coating agent in the process (II), a
polyvinyl alcohol (degree of polymerization 500 and
saponification degree 80~) is employed to prepare a
2059617
- 55 -
1 0.5~ water solution, and in such a solution, the
ceiling plate material is immersed and dried
naturally fpr 30 minutes after being lifted
therefrom. Here, polysulfone is used for the
material.
Then, after the discharging ports are -
machined likewise, the discharging port plate is w
immersed in a water as the process (IV) for a five-
minute ultrasonic cleaning.
Embodiment 16
Subsequently, the description will be made of
the embodiment in which a metallic film is used for
a film as a method for removing the carbon and
others deposited particularly on the surface of the
orif ice plate .
For the ceiling plate material, polyether
sulfone is used:
In the present embodiment, aluminum (AI)
is provided on the surface of the orifice plate for
a thickness of approximately 0.3 to 0.5 pm by
sputtering. Then; after the discharging ports are
machined in the process (III), the discharging port
plate is immersed in a phosphoric solution for a
three-minwte ultrasonic cleaning. The polyether
sulfone has a desirable chemical resistivity
against phosphoric acid, and as there rarely occurs
a crack in the ceiling plate, it is easier to remove
- 56 - 205961'
1 the film.
Comparison example 2
In order to compare the above-mentioned
embodiment, a ceiling plate is obtained by
machining discharging ports on the ceiling plate
material which has been prepared through the
process (I) but not through the process (II),
subsequent to which, the plate is immersed in a
water for a five-minute ultrasonic cleaning. Here,
polysulfone is used for the ceiling plate material.
As regards the above-mentioned embodiments 13
through 16 and the comparison example 2, the
processes thereof; the evaluation of the carbon
removal states of the ceiling plates, and the
evaluation of the printing conditions are tabulated
together and shown in Table 5.
5' - 2Q~~61~
U U
1 r-I ri
Q1
. ro W
+~
xro ~ro o 0 0 o x
a ~ a
~~
H , O
O ~1
01
wl ~1-~
Ol .4.~
rl
tn to o O o o x
.fl
~~ro~
o ~N
~ a ~
a~
U~ro+
U ~
ro
o x
ro s~ O O O
ro U
ro t~
a~ a~
U
~ C1
N
E
p 4a
t0 ~
G
fx o
r-i
.--
H
N
G G
W O U U w-1 U
U
i." U .S", ri r-I rl
r1 N -.~
c~ o o a o~ s~ ~ o~ c cr
x .~ a s~ s~
a
a -~ ~ o a a~ o a 0 ~ a~
a~ ro a~ o
0
~f'7 rl +~ O N fJ) rl fn N rl
-,-I ~ r-1 +~ w-f +~
..S"'.
rl
a-~~ro a~ro ~a~, ~oa~o roar.~+rroaro
~o ro M a~ ~, ro 3 s~ s~ ro
a~ ro x x ro 3
x N
~
a~ a A ~ +~ a~ +~ +~ a~
+~ s~ o a~
.~ o
~
.a ~ ow CEO E ~~ a ~~-a.a-~~ a
N a o
U U t0 z H ~ U rl ~ U ~ U ri
H -~-1 ~. -rl S~
U1
Q G
O t O -~-I
Z71 r-I O r~ rl S-a
r1
~
~ ~ .1-~ N G 1-1 .1~
i O a f-I
S.a
!-!
+~ .T' ~ ri :1 r~ N .i~
e-I N
N
N
ro
o a~ ro ~ ro ~ w a~
s~ ~
w
v ~ z z ro ~o cn
ro ~
~s
-~
rn ~., s~
+~
a .N ~ ow ~ a~
a
ri ~ w mn +~
~I O
0 0 0 3
O tnN
O
U t0
L1 U7
G ro
M dm n O O ~
--m --I ~-I .-1 .~--1 ro
-. -'I
c0 b +~ .1.~
x +~ +~ ~ o +~ +~ o
x m ~w c~
2 5 ~ O G ~ rl N ~ ~I t~
~ ,f'.,O U O
l
i
N N tn N ~C r1
rl W O O r ~ N
O ~ ao Sa r-1
~ N >, ~--I
O r
~ G' O
1-1 4d
+~ C wl w1 w1 r-I .-I ~ ,~
oo M .~ N N f,~,
O O w1 p
ro a~ ro ro ro ~ O ro O ~ s
t ~o ~ a~ a H
~ a~
o is o o o ~, U o ~ a~ .~
r~ ~ ~ s~ o ~ b
x x s~
U ro .n ~ .Q ~ ~ .~ a ~,
w r~ ~ rn n~ o x
o o
E E E O ~tS E O p.,
t=. ~ O N ro U p
E E-~ N
W W W W W ro W .r
O O U7 ro
v ~
2~59~1'~
- 58 -
1 As clear from this table, there is no
residual carbon recognized at all in each of the
embodiments 13 through 15 when the removal
conditions of the deposited carbon are observed by
a metallurgical microscope. On the other hand,
there are observed in the comparison example some -
cases where just a half of the carbon deposition
has been removed or no carbon has been removed at
all.
Also, actual printing durability tests are
conducted on the recording heads completed with the
ceiling plates thus obtained. Then, as shown in
Table 5, while there are some cases where a
disabled discharging occurs due to the clogging of
carbon particles in the comparison example, no
disabled discharging has taken place in each of the
embodiments 13 through 15 during the durability
test (up to 2,000 sheets of an A4-sized recording
medium) and the printing conditions are desirable
to the end. Also, there occur no ink puddles on
the surface of the orifice plate and a desirable
printing is performed with a stable flying
orientation of the ink droplets.
Embodiment 17 '
In the above-mentioned.embodiments, all the
coating layer is removed in the cleaning process so
that no residual carbon may remain at all.
- 59 -
1 However, it may also be possible to allow the
coating layer to remain unremoved from the location
where no carbon is present or the location where
the carbon is present but in a negligible quantity.
For example, in a case where a photoresist coating
is performed, it is possible to cause the coating -
layer to be removed or remain unremoved from a desired --
location selectively in the cleaning process by
conducting a selective light irradiation before
cleaning (for example, if a positive type resist is
used, the cleaning should be given subsequent to
the light irradiation locally to a portion where
the removal is desired, or if a negative type resist
is used, the cleaning should be given subsequent to
the light irradiation locally to the portion where
the coating is to remain unremoved).
This contributes not only to the reduction
of the cleaning liquid and cleaning time, but also
to the event given below in an ink jet recording head.
In other words, in the ink jet recording head,
a liquid repellence treatment is given to the plane
where the discharging ports are arranged (a
discharging port arrangement plane or orifice plate
surface in the above example) in some cases. This
treatment is given in consideration of the fact that
if the wettability of the discharging port arrangement
plane is high, a part of ink tends to remain on the
20596~.'~
- 60 -
1 discharging port arrangement plane when the meniscus
is returned after the ink discharging operation,
which results in drawing the ink to be discharged
next time thereby to twist its discharging direction.
In the present embodiment, a resin having
liquid repellency is coated in the process (.II) in
order to cope with such a situation as this, and
before the process (IV), there is performed a light
irradiation to or shield from the discharging port
arrangement plane which corresponds to the resist.
Fig. 10 is a view showing the ceiling plate
5A which is obtainable after cleaning subsequent to
the above processes and on the front face of the
orifice plate 10, a film 16A remains to serve as a
liquid repellence layer. According to the present
embodiment, there is no need of providing a liquid
repellence layer separately or any process in a
recording apparatus that may perform an automatic
coating or the like.
Here, in such a liquid repellence layer as
in the present embodiment, it may be possible. to
cause only the required portion in the circumference
of the discharging ports to remain or if desired, it
may be possible to cause such a layer to remain in
some other portion (a predetermined portion in the
reverse side of the orifice plate or in the ink pass).
In either case, it is possible to obtain remaining
- 61 -
1 portions as desired by controlling the irradiation
of light or shielding thereof.
Furthermore, in the above-mentioned example,
when the resin coating is given, the ceiling plate
material is immersed in a resist solution. However,
the present invention is capable of defining the kinds
of the functionable layer, the layer deposition or the w
location thereof as a matter of course and is not
limited to the example set forth above.
Others
In this respect, particularly among those
available ink jet recording methods, the present
invention is provided with means (for example,
electrothermal converting element, laser light, or the
like) for generating thermal energy as the energy
which can be utilized for discharging ink because with
the present invention not only it is possible to bring
about an excellent effect in a recording head or a
recording apparatus having such a method as generating
a change of state for ink by the aforesaid thermal
energy, but also it is possible to attain a higher
density as well as a higher precision of recording by
the use thereof.
For the typical structure and principle of
such a method for the implementation thereof, it is
preferable to adopt the fundamental principle
disclosed in the specifications of U.S. Patent 4723129
- 62 -
1 and U.S. Patent 4740796, for example. This method is
applicable both to the so-called on demand type and
continuance type. Particularly, in the case of the on
demand type, there is applied at least one driving
signal which gives a rapid temperature rise above the
nuclear boiling to a recording liquid (ink) in -
response to the recording information provided for the w
electrothermal converter arranged with respect to a
sheet or liquid pass in which a recording liquid (ink)
is held. Thus the electrothermal converter is caused
to generate thermal energy and a film boiling on the
thermo-active plane of the recording head. In this
way, the formation of bubble is made efficiently in
the recording liquid (ink) one to one in response to
such a driving signal. Then, the recording liquid
(ink) is discharged into the atmosphere through the
discharging ports by the active force generated in the
course of the growth and contraction of this bubble to
form at least one droplet. It is more preferable to
produce this driving signal in the form of pulses.
Then, the growth and contraction of the bubbles are
appropriately effectuated instantaneously to implement
the discharging of recording liquid particularly with
an excellent responsibility. For this type of pulse
driving signal, the one such as disclosed in the
specifications of U.S. Patent 4463359 and U.S. Patent
4345262 is suitably adoptable. In this respect, it is
- 63 -
1 possible to perform such an excellent recording still
better if the conditions referred to in the invention
on the temperature rise for the above-mentioned
thermo-active plane disclosed in the specification of
U.S. Patent 4313124.
As the structure of the recording head, the -
present invention includes a combination of the w
discharging port, liquid pass, electrothermal
converter (linear liquid pass or rectangular liquid
pass) such as disclosed in each of the above-mentioned
specifications as well as the structure having the
thermo-active portion arranged in the bending region
using the configuration disclosed in the
specifications of U.S. Patent 4558333 and U.S. Patent
4459600. In addition, the present invention is
effective when its structure is arranged on the basis
of the Japanese Patent Laid-Open Application No. 59-
123670 which discloses a.structure whereby to make a
common slit to be the discharging ports of the
electrothermal converters or of the Japanese Patent
Laid-Open Application No. 59-138461 which discloses a
structure whereby to arrange the discharging ports in
relation to the opening holes which absorb the ' '
pressurized waves of thermal energy. In other words,
this is possible because according to the present
invention, a recording can be performed assuredly and
efficiently irrespective of the modes of the recording
- 6 4 --
1 heads.
Further, as to the full-line type recording
head having a length corresponding to the maximum
width of the recording medium on which the recorder
can perform its recording, the present invention can
also be adopted effectively. For such a recording -
head, there may be a structure made either by
combining a plurality of recording heads or by an
integrally constructed single recording head to attain
such a recording length.
In addition, the present invention is
effectively applicable either to the above-mentioned
serial type recording head, the recording head fixed
to the main body of the recording apparatus, a freely
replaceable chip type recording head for which the
electrical connection to the main body of the
recording apparatus as well as the ink supply from the
main body of the recording apparatus become possible
when the chip is installed therein, or a cartridge
type recording head having the ink tank integrally
provided for the recording head itself.
Also, it is preferable to add a recovery
means, preliminarily auxiliary means, and the like
provided for the recording head as constituents of the
recording apparatus according to the present invention
because with these constituents, the effect of the
present invention becomes more stable. To mention
2~5~617
- 65 -
1 specifically, these constituents are a capping means
far the recording head, c.~eaning means, compression or
suction means, electrothermal converter or thermal
element independent thereof or preliminary heating
means provided by the combination thereof, and others.
Also, it is effective to provide a preliminary -
discharging mode which performs preliminary
discharging besides the recording.
Also, as to the kinds and numbers of the
recording heads to be mounted, it may be possible to
adopt those having a plurality of recording heads for
plural kinds of ink which are different in recording
colors or densities in addition to the one having only
one head for a single color ink, for example. In
other words, the present invention is extremely
effective when applied to an recording apparatus
provided with at least one of the respective recording
modes for compound colors by different colors or full
colors by color mixtures irrespective of whether the
recording head is constructed integrally for a single
head or by combination of plural heads for the
recording mode of the apparatus which is not confined
only to a major color such as black.
Furthermore, in the embodiments of the present
invention set forth above, while the description has
been made of the ink which is a liquid, it may be
possible to use the ink which is solidified at room
~~5961'~
- 66 -
1 temperature or less if only such ink can be softened
or liquefied at room temperature, or if only such ink
can be liquefied when a signal to use for recording is
given because in an ink jet method, it is generally
practiced that ink itself is kept within a temperature
range of 30°C or more and 70°C or less to maintain its
viscosity in a range of stable discharging. In
addition, the temperature rise to be caused by the
thermal energy is positively prevented by using such
energy for changing the state of ink from solid to
liquid, or for the prevention of ink evaporation, it
may be possible to use the ink which is solidified
when it is left intact but can be liquefied by
heating. In any event, the present invention is also
applicable to the ink which is liquefied in response
to the provision of the recording signals generated by
the thermal energy for discharging such a liquefied
ink, or the ink which has a property to be liquefied
only by the provision of thermal energy and which
already begins to be solidified just before reaching a
recording medium or the like. When an ink such as
this is used, it may be possible to adopt a mode in
which the ink is held in a state of liquid or solid in
concavities of a porous sheet or through holes so that
the ink is placed to face the electrothermal converter
as disclosed in Japanese Patent Laid-Open Application
No. 54-56847 or Japanese Patent Laid-Open Application
259617
- 67 -
1 No. 60-71260. In the present invention, the mode
which enables the implementation of the above-
mentioned film boiling method is the most effective
for each of the above-mentioned kinds of ink.
Moreover, as to the mode of the ink jet
recording apparatus to which the present invention -is
applicable, there may be those used for copying
machines in combination with readers, and facsimile
apparatuses having transmitter and receiver, or the
like in addition to the image output terminals for a
computer or other information processing apparatuses.
Now, as described above, in an ink jet
recording head according to the present invention,
there is formed in the circumference of the orifice a
water repellence treatment portion which is excellent
both in water repellency and durability. Hence, it is
possible to perform the stable discharging printings
at all times for obtaining desirable quality in
printing.
Also, as described above, by irradiating a
pulse laser onto the orifice plate having a water
repellence layer on its face or being constructed
itself with a water repellent agent for the orifice
machining and then by restoring the water repellency
in the vicinity of the orifice with the removal or a
treatment given to the removal of the by-product
having a great hydrophilic property adhesively
2 0 5'~ 6 ~.'~
- 68 -
1 deposited in the vicinity of the orifice, it is
possible to provide an ink jet recording head and
manufacturing method therefor capable of preventing
the adhesion of ink to the vicinity of the orifice and
the degradation of the printing quality as well.
In this respect, by using a water repellent-
film material for the utilization of the carbon w
removal and allowing such a film to remain
selectively, it is also possible for the present
invention to contribute to simplifying the
manufacturing processes because there is then no need
of performing any separate process for giving the
liquid repellence treatment to the discharging port
arrangement plane.
20
