Note: Descriptions are shown in the official language in which they were submitted.
2177986
`~ --
The present invention relates to capacitive
and/or resistive components of the stacked type, as
well as to a process for fabricating a component of the
stacked type.
The invention will more particularly be
described for the fabrication of capacitors of the
stacked type. However, as will be indicated hereafter,
the invention also relate8 to the fabrication of
resistors .
Capacitors of the stacked type can be
fabricated in various ways. One of these ways consists
in using metallized flexible plastic films.
The flexible plastic films then generally have
a me~l l; 7e~ zone and an unmetallized side margin and
are obtained by cutting a wide reel of metallized
f lexible plastic f ilm.
One of the steps of the fabrication process
consists in winding at least one pair of metallized
flexible plastic films on a wheel which has a large
diameter. The winding is carried out in such a way that
the unmetallized margins of two films which are
superposed lie on opposite sides.
This produces a capacitive strip of desired
thickness according to the number of turns made. Each
of the flanks of the capacitive strip is then covered
with a metal or metal alloy.
This is the shooping operation intended to
create the output plates of the future capacitors. The
capacitor strip thus obtained is called a mother
capacitor. The mother capacitor is then cut into
unitary blocks called semifinished capacitors.
3 5 Another way of producing capacitors of the
stacked type consists in assembling metallized
dielectric sheets . The me~1 1 i 7e~1 dielectric sheets are
assembled by sintering af ter the sheets have been
" 2177~8~
stacked flat on one another.
It is then nprp~s~ry to cut the assemblies thus
constituted and to produce the plates of the elementary
capacitors .
It is also known to produce capacitors on a
glaæs substrate, these capacitors consisting of two
metal electrodes framing a dielectric layer formed in a
discharge plasma.
The drawback of such procesæes consist9, on the
one hand, in their large number of steps and, on the
other hand, in that the rr~mrrnPnt~ obtained have
relatively limited capacitances per unit volume because
of the nature and the thickness of the dielectrics
used .
By way of example, the dielectrics used for
producing the plastic films involved in the composition
of capacitors with metallized flexible plastic films
are polyester, polycarbonate, phenylenepolysulphide or
else polypropylene The capacitance per unit volume
obtained does not exceed lO nanofarads per cubic
millimetre .
The invention does not have these drawbacks.
The present invention relates to a novel
capacitor ~tructure with high capacitance per unit
volume. As will become apparent hereafter, it is
unexpectedly possible to orm resistors of the stacked
type by modifying this novel structure.
The invention thereore proposes a capacitor of
the stacked type, consisting of an alternation Qf
dielectric layers of odd and even rank and of
conductive layers of odd and even rank, the said
stacked capacitor constituting a structure having two
opposite side faces covered with conducting materLal,
characterized in that t~e ~l;plPr~ric layers are
obtained by thin-film deposits of dielectric elements
and the conductive layers are obtained by thin-film
deposits of conducting Pl PmPn~, the covering of a
first side face with conducting material being obtalned
by the said deposits of conducting elements so as to
" 2177~8~
3 -
connect together electrically the conductive layers of
even rank, and the covering of the side face opposite
the said first face with conducting material being
obtained by the said deposits of conducting elements so
5 as to connect together electrically the conductive
layers of odd rank.
The invention also proposes a resistor,
characterized in that it i9 formed by the successive
stacking of dielectric thin films and conductive thin
10 films, the conductive thin films constituting
superposed elementary resistive element6 connected in
series with one another during the stacking.
More precisely, the resistor according to the
invention is characterized in that it consists of an
15 alternation of dielectric layers of odd and even rank
and of conductive layers of odd and even rank, the said
alternation constituting a structure having two
opposite side faces covered with conducting material,
the dielectric layers being obtained by thin-film
20 deposits of dielectric elements and the conductive
layers being obtained by thin-film deposits of
conducting elements, each conductive layer having a
first end located on a first side face and a second end
located on a second side face, opposite the first side
25 face, a conductive layer of odd rank having its first
end electrically connected to the first end of the
conductive layer of even rank immediately above r and a
conductive layer of even rank having its second end
electrically connected to the second end of the
30 conductive layer of odd rank immediately above, the
electrical connections between the said ends being
produced during the deposition of the conductive
layers .
The invention also relates to the combination
3 5 in series or in parallel of at least one resistor and
of at least one capacitor such as those mentioned
above.
The invention also relates to a process for the
fabricating of a capacitor of the stacked type,
217~7981~
consisting of a succession of dielectric layers and
conductive layers, characterized in that the dielectric
and conductive layers are made respectively by thin-
film deposition of dielectric elements and by thin-film
deposition of ~onducting elements.
An important advantage of this process for
fabricating a capacitor is that it makes it possible,
during the deposition of the conducting elements, to
cover with conducting material the two opposite side
faces intended to become the plates of the capacitor.
The invention also relates to a process for
fabricating a resistor, characterized in that it
consists in forming a succession of dielectric layers
and of conductive layers by respective thin- f ilm depo-
sitions o~ dielectric eleménts and thin-film depo-
sitions of conducting elements.
An important advantage of this process of
fabricating a resistor is that it makes it possible to
connect the t~nnr7l7n7-;ve layers in series with one
another during the deposition of the conducting
elements .
According to the preferred Pmhn~7imF~n~ of the
invention, the dielectric and conductive thin films are
deposited in the presence of a re~mote nitrogen plasma,
the dielectric layers are then deposited by poly-
merization of elements resulting from the remote
nitrogen plasma dissociation of an organosilicon or
organogermanium gas, and the conductive layers are
produced by depositing conducting elements resulting
from the remote nitrogen plasma dissociation o~ a
precursor gas of these conducting elements. I~he
precursor gas of the conducting elements may be a metal
complex or else hydrogen sulphide or sulphur
dichloride .
According to an important aspect of the
invention, the process for depositing the alternately
dielectric and conductive thin films is implemented in
a reactor which comprises at least two deposition
cavities: one is reserved for the deposition of
`. 21779~
5 -
dielectric layers and the other is reserved for the
deposition of conductive layers, the deposition
operations being carried out simultaneously on the same
substrate advancing cyclically through the two
5 cavities.
Other characteristics and advantages of the
invention will emerge on reading a preferred embodiment
given with reference to the appended figures, in which:
- Figure 1 is an outline representation of a
10 flowing discharge plasma as employed according to the
invention;
- Figure 2 is a block diagram of the device
according to the invention;
- Figure 3 is a detail view of the block
diagram in Figure 2;
- Figure 4 is a sectional view of a capacitive
structure obtained according to the invention;
- Figure 5 is a sectional view of a resistive
structure obtained according to the invention;
- Figure 6 is a sectional view of a resistive
and capacitive structure obtained according to the
invention;
- Figure 7 is a sectional view of a masking
device used according to the invention.
25 -The same references denote the same Pl~--^ntq
throughout the f igures ~
Figure 1 is an outline representation of a
f lowing discharge plasma as employed according to the
invention .
A nitrogen supply source 2 i6 sent via a tube 3
into a microwave cavity 4.
The nitrogen pressure inside the tube 3 is
between 1 and 20 hPa. Under the effect c~f the wave
generated by the microwave generator, a discharge is
sustained in the cavity 4. The frequency of the wave
output by the microwave generator 5 is~ for example,
equal to 2450 MHz, to 433 MHz or to 915 MHz. The flow
produced by a vacuum pump (not represented in Figure 1)
is established along the z axis. The hatched zones
2177~8~
6 -
symbolically represent the distribution of ions and
electrons present i~ the discharge plasma exit zones
situated between the output of the discharge cavity and
the vacuum pump.
Zone Z1 ie a first post-discharge zone in which
the concentration of ions and electrons decreases
continuously between the output of the discharge cavity
and a highly localized extinction zone represented by
the point P.
The zone Z2, which follows zone Zl, is a second
ion post-discharge zone in which the concentration of
ions and electrons is not negligible. It i8 more
extended than zone Z1.
The zone Z3, which follows zone Z2, is a zone
intermediate between zone Z2 and zone Z4, which
contains subst~nt~ally no electrons and ions. The con-
centration of ions and electrons decreases continuously
between the second part of zone Z2 and zone Z4.
Zone Z4 is a post-discharge zone which may have
a wide spatial extent.
In zone Z4, the effective lifetime of the
energy carriers, in particular vibrationally excited
nitrogen, iB advantageously long. Lifetimes of the
order of 10 seconds have been measured. Advantageously,
it is therefore the flowing remote plasma located in
this extended post-discharge zone which is used accor-
ding to the invention. By way of example, it has been
measured that the distance separating the output of the
cavity 4 from the start of zone Z4 may be greater than
3 o or equal to 1 metre .
Figure 2 is a block diagram of the device
according to the invention.
A dielectric substrate 1 is arranged on a drum
2 which rotates at angular velocity Q. This substrate,
the function o~ which is to serve as a support, may be
made of any material whose electrical characteristics
do not i~terfere with the electrical characteristics of
the components resulting from the process.
According to the prior art, discharge plasma-
" 21779~6
..
7 -
enhanced depositions are carried out on heated
substrates . Another advantage of deposition by f lowing
remote cold plasma i9 that it is not n~r~qpilry to heat
the substrate on which the deposits are made. The
5 mechanical cha~acteristics of the substrate are there-
fore not degraded and the reliability of the, ,-nl~nt~
resulting from the process of the invention is improved
compared to that of components resulting from processes
of the prior art.
According to the preierred embodiment of the
invention, the same portion of the dielectric material
1 successively faces a first masking device DM1, a
f irst cavity C1 in which the f irst dielectric
deposition takes place, a second masking device DM2, a
15 second cavity C2 in which the first conducting polymer
depo~ition takes place, a third masking device DM3, a
third cavity C3 in which the second dielectric
deposition takes place, a fourth masking device DM4,
and a fourth cavity C4 in which the second conducting
20 polymer deposition takes place.
The drum 2, cavities C1, C2, C3 and C4, as well
as the masking devices, are located inside the same
reactor 6.
The masks deposited by the masking devices DM1,
25 DM2, DM3 and DM4 will be described hereafter, as will
the masking devices themselves (cf Figures 3, 4 and
5) .
According to the preferred embodiment of the
invention, the dielectric layers deposited in the
30 cavities C1 and C3 are obtained by polymerization of
elements resulting from the remote nitrogen plasma
dissociation of a precursor gas of the deposit, such as
an organosilicon or organogermanium gas.
The remote plasma used is a flowing remote cold
35 plasma. The flowing remote cold plasma is obtained at a
pressure of a few hPa, by extraction and relaxation in
a reactor, outside the electric :Eield, of the active
species formed in a discharge plasma.
As previously described, the flowing remote
2177~
-- 8
cold plasma according to the invention ~-nnt~;nc
practically no electrons or ions~ The reactive species
are Pss~nt;~7ly atoms, free radicals and electrically
and vibrationally excited molecular species. Such a
5 remote cold plasma can only be obtained in regions
relatively far from the cavity 4. The result of this is
that the distance separating the output of the cavity 4
from the surface 1 where the depositions take place
should be selected accordingly. By way of example, this
10 distance may be greater than or equal to 1 metre.
In the present case, a nitrogen supply source 3
i8 sent into a microwave cavity 4, via a tube 19. The
nitrogen Fressure inside the tube 19 is between 1 and
20 hPa~ Under the effect o the wave generated by the
15 microwave generator 5, a discharge is sustained in the
cavity 4~ The frequency of the wave output by the
microwave generator 5 is, for example, equal to
2450 Mhz, 433 Mhz, or 915 MHz~ The nitrogen, excited at
the output of the microwave cavity 4, is sent via tubes
20 9 into cavities C1 and C3 where the dielectric
depositions are to take place. The percentage of
nitrogen dissociated is, by way of example, between 0 5
and 3 per cent.
The organosLlicon-containing or organo-
25 germanium-cnnr~;ning gas output by the source 1~7 is
introduced into the cavities Cl and C3 via a device 8,
the diagram of which will be detailed in Figure 3. The
f lared end 7 of the device 8 allows the gas to spread
over the surface on which the dielectric deposit is to
3 0 be made .
The excited nitrogen is therefore mixed with
the precursor gas .of the deposit in the zone situated
between the flared end 7 of the device 8 and the
surface where the polymerization takes place. This
35 flared e~d is situated in the ~oYt~nr~ nonionic post-
discharge zone of the 10wing nitrogen plasma. The flow
is produced using a vacuum pump 14. For reasons of
convenience, the vacuum pump 14 has been represented
symbolically in Figure 2. It is preferably arranged
21 77~
g
along a generatric of the drum 2 and is divided on
either s; (l.o of the flared end 7 . As mentioned above,
the precursor gas of the deposit may be an
organogermanium compound. It may also be an
5 organosilicon - compound chosen from alkoxysilanes,
siloxanes or s~ 1 A7:~n~ . According to the preferred
embodiment of the invention, it is
tetramethyldisiloxane .
The use of a remote plasma in the F~ n~l~d
10 post-discharge zone is an advantage of the invention.
Indeed, in comparison with conventional discharge or
post-discharge plasmas, remote plasmas in the extended
post-discharge zone are active media deprived of
electrQns and free of energetic radiation over a large
15 spatial extent . The absence of an electric f ield
promotes the deposition of heavy elements on the
conductive layers and improves the deposition rate.
Furthermore, as already mentioned above, the effective
lifetime of the energy carriers is advantageously long
2 0 therein
According to the preferred embodiment of the
invention, the devices 8 for injecting the gaseous
organosllicon compound are connected to the same oxygen
source 11. The introduction of oxygen into the cavities
25 C1 and C3 at the same time as the organosilicon
compound advantageously accelerates the rate of
formation of the dielectric layer on the conductive
layer. Another advantage of the presence Qf oxygen is
the i~Qrmation of polar groups, guch as OH groups, in
30 the dielectric layers deposited. This results in an
improvement of the dielectric constant of the material.
The oxygen content is of the order of a few per cent of
the gas mixture present in the cavities C1 and C3. It
may reach values of lD to 15~ for large deposition
3 5 chambers .
Another dopant 12 may be introduced into the
reactor by the injection devices 3. This may, for
example, be a gas from the tetrakisdialkylamidotitanium
Iv family. This second dopant then makes it possible to
1 0
formation of polar group6. In this case, the polar
groups are based on titanium oxide.
An advantage of the invention is the deposition
of a dielectric layer which has excellent qualities of
5 adhe6ion and homogeneity and the thickness of which
obtained can vary, as required, from 0 . 05 micron to a
f ew mi cror s
The organosilicon compounds introduced into the
reactor may be: -
an alkoxysilane of formula
Rl
I
o
Rl-O- [Si-O] n~R3 with n less than or equal to 5
H
a siloxane of formula
R2
I
R - [Si-O] -R with n less than or equal to 4
l n 3
H
or s;l~37~nPq of formula
3 0 R2 R2
Rl- [Si-NH]n-Si-Rl with n less than 4
H H
The relative dielectric constant of the
deposits obtained may reach values of more than 30.
According to the in~enti~n, the oxygen source ll or the
dopant of the precursor gas 12 may contain titanium
` ~ 217~
1 1 --
oxide, for example titanium (IV) isopropylate, in order
to enhance further the value of the relative dielectric
constant of the deposit. It is a priori already known
to the person skilled in the art that dielectrics
5 having high relative dielectric constants of ten have
high losses, as well as poor thermal stability.
In the present case, it was observed that the
dielectric deposit accordins to the invention did not
have these drawbacks.
The thermal stability is improved, and the
maximum working temperature may reach of the order of
300OC.
The breakdown voltages of the dielectrics are
also greatly improved and may reach, for e~campler 2, 000
15 volts per micro.
In general, the process according to the
invention relates to variou~3 precursor gase~3 of the
deposit (organogermanium, alkosysilane, siloxane or
silazane compound).
The process accordlng to the invention thus
makes it possible advantageously to polymerize various
dielectrics on the conductive layers.
sy way of example, when a silazane is
introduced into the cavities Cl and C3, a dielectric
layer formed by the following compounds is obtained:
-si -NH-Si
-si -o -si
-si-c -si
When a siloxane is introduced, a dielectric
layer formed by the following compounds is obtained:
crosslinked (Si-o-Si) polymer
-Si- (CH3)
-Si -OH
-Si-NH-Si
for a very low oxygen content
217798~
- 12 -
or else:
crosslinked (Si-O-Si~ polymer
-Si- (CH3) 2
-Si- (CH3) 2
-Si -OH_
-SI -NH-Si
for a higher oxygen content.
According to the preferred embodiment of the
invention, the dopant gas is oxygen. According to other
embodiments, it may, more generally, be a gaseous
compound rrnt~; n; nr oxygen .
As mrntirnPri above, the same portion of
material is subjected to a deposition of conducting
elements after having been subjected to a dielectric
deposition. This deposition of conducting elements
takes place in cavities C2 and C4.
According to a f irst embodiment of the
invention, the conducting elements are conducting
polymers deposited by polymerization of e~mf~ntq
resulting from the remote nitrogen plasma dissociation
o~ a precursor gas of the deposit, such as hydrogen
sulphide or sulphur dichloride. By radical
recombination of the SN radical, the conducting
polymers are -sulphur polynitrides of chemical formula
S4Nq or (SN) x, x being an integer greater than 4 .
According to another embodiment of the
invention, the conducting elements deposited result
from the remote nitrogen plasma dissociation of a metal
compl ex .
This metal complex may be a ~netal carbonyl such
as, f or e~ample, iron carbonyl or nickel carbonyl, or
else an acetyl acetonate or a fluroacetyl acetonate.
The remote plasma is a flowing remote cold
plasma analogous to that produced for the deposition of
3 5 the dielectric .
A nitrogen supply source 15 18 sent into a
cavity 16 via a tube 20. The nitrogen pressure inside
the tube 20 is between 1 and 20 hPa. Under the effect
Qf the wave generated by the microwave generator 17, a
` 2177~8&
- 13 -
discharge iB sustained in the cavity 16. The frequency
of the wave output by the microwave generator 17 is,
for e~ample, equal to 2450 MHz, 433 MHz or 915 MHz. The
nitrogen, excited at the output of the microwave cavity
16, i3 sent via tubes 28 into the cavities C2 and C~
where the conducting polymers are to be deposited. The
quantity of sulphur is preferably slightly in excess
relati~e to the quantity of nitrogen, so that the
conducting polymer has better conductivity
10 performances.
The hydrogen sulphide or sulphur dichloride
produced by the source 13 is introduced into the
cavities C2 and C4 via a device a, the diagram of which
will be rlPt~ in Figure 2. The flared end 7 of the
device 8 makes it possible for the gas to spread over
the surface where the conducting polymer is to be
deposited .
The exc~ted nitrogen is therefore mixed with
the precursor gas of the deposit in the zone situated
between the flared end 7 of the device 8 and the
surface where the polymerization is to take place. This
flared end is sltuated in the nonionic P~t,~nr~Pr~ post-
discharge zone o~ the flowing nitrogen plasma. The flow
is produced using a vacuum pump 14.
Advantageously, the process according to the
invention makes it possible to produce conducting
polymer layers having smaller thicknesses. These
thicknesses may actually be of the order of ~ . 05 llm.
According to the preferred ~ n~ described
in Figure 2, two dielectric layers and two conducting
polymer layers are depos~ted on each revolution of the
drum 2.
The invention relates, however, to other
embodiments, ~or example tEle embodiment in which a
single dielectric layer and a single conductive layer
are deposited, and also the embodiments in which more
than two dielectric layers and more than two conducting
polymer layers are depoelted. The dielectric layers, as
well as the conducting polymer layers, may then be of
~ ~ - 14 - 2~7798~i
different nature. To this end, it is suficient to
increase the number of deposition cavities according to
the deposits desired.
Figure 3 is a detailed view of the block
diagram in Figure 2.
This view represents the injection device 8. A
set of inj ection tubes 22 is contained in a sleeve 21
which comprises a flared part 7 at its end. Each
injection tube 22 opens into an orifice 23 in the
flared part of the sleeve.
As mF~nt;~n~ above, the injection devices s are
used both for the deposition o~ dielectrics and for the
deposition of conducting polymers.
Thus, the injection tubes 22 which are
connected to the sources 10, 11 and 12 convey gases
required for depositing the dielectric layers.
Similarly, the injection tubes 22 which are connected
to the source 13 convey the gas required or depositing
the conducting polymer layers.
Figure 3 represents the injection device 8
according to the pref erred embodiment . In general, the
injection device 8 may be any system which is known to
the person skilled in the art and makes it possible to
distribute the precursor gases of the deposit uniformly
over the sur~ace where the deposition takes place.
Figure 4 is a sectional view of a capacitive
structure obtained according to the preerred
embodiment Qf the process, described in Figure 2
Figure 4 also symbolically represents the masks
MA1, MA2, MA3, MA4 associated with the respective
masking devices DMl, DM2, DM3, DM4.
The various masks MAi ( i = 1, 2, 3, 4 ) are
preerably produced by oil deposition on the zones
where the dielectric and conducting polymer depositions
are not allowed. The devices making it possible to
produce these masks will be described in Figure 7.
Mask MA1 is produced by oil depositions H1 on
the zones to be protected from dielectric deposition.
The oil produced by the masking device DM1 is deposited
` ,~ 2177986
- 15 -
along the surface 1 as a result of the rotation of the
drum 2. Each oil deposit H1 has a width 11 whose value
is preferably of the order of 50 to lOo ~m. The oil
deposlts H1 are arranged parallel to one another and
pre~erably equidistant. Their distance may, for
example, be of the order of 1 to 2 mm.
The mask MA2 is produced by oil deposits H2 on
the zones to be protected from the conducting polymer
deposition. The oil produced by the device DM2 is
o deposited according to the same principle as the one
described above. The width 12 of the oil deposits H2 is
greater than the above width 11. The width 12 is
. preferably greater than the width 12 by 20 to 30~. The
oil deposits Hl and H2 are produced along parallel
axes. The deposits H2 are thus arranged in such a way
that each of the axes defi~ed by a deposit H2 is
juxtaposed with an axis defined by a deposit H1, the
distance separating the axes defl~led by two
neighbouring deposits H2 being twice that separating
the axes defined by two neighbouring deposits H1.
The mask MA3 is produced by oil deposits H3.
This third mask MA3 is identical to the first mask MA1.
The oil deposits H3 are ;~ nti~-~l in width and in
position to the oil deposits H1.
The mask MA4 ic produced by oil deposits H4.
Each deposit H4 has a width ;~nt;~l to the width of
the deposits H2. Two neighbouring deposits H4 are
separated by the same distance as two neighbouring
deposit~ H2. However, the axis which a deposit H4
defines is not superposed with the axis which a deposit
H2 defines, but is equidistant between the axes defined
by two neighbouring deposits H2.
As mentioned above, the formation of the
capacitive structure according to the preferred
embodiment of the invention results from the
deposition, on each revolution of the drum 2, o~ two
dielectric layers and two conducting polymer layers.
The capacitive structure in Figure 4 comprises, for
reasons of convenient representation, six dielectric
" 2177986
16 -
layers and six conductive layers. This structure thus
corresponds to three revolutions of the drum 2. More
generally, the number of revolutions of the drum 2 may
be much larger and the number of layers may reach
5 several thousands.
The capacitive structure according to the
invention is in the form of a set o N elementary
capacitive structures Si (i = 1, 2, . . ., N) in parallel
These structures are advantageously separated from one
10 another by wells Pi (i = 1, 2, , N-l) . These wells
are as many zones as and make it possible to facilitate
the cutting of the capacitive structure into elementary
capacitive structures.
The cutting can then be ~arried out by any
means known to the person skilled in the art.
Advantageously, accordlng to the invention, it may also
be carried out by a cutting system compatible with the
masking devices, ag will be indicated hereafter (cf.
Figure 7 ) .
AccordLng to the invention, the side walls of
each elementary capacitive structure are conductive. It
is then sufficient either to pass each elementary
capacitive structure through a molten alloy wave or to
deposit a soldering alloy or soldering cream on the
side walls of each elementary capac~tive structure, in
order to produce the plates of the future capacitors.
The shooping operation which was necessary, according
to the prior art, for fabricating capacitors with
metalli~ ed plastic f ilm sheets is no longer necessary
according to the process of the invention.
More generally, the process of the invention
advantageously reduces the number o successive steps
making it possible to produce capacitors o the stacked
type .
3 5 Once the plates have been produced, the process
according to the invention comprises a step of cutting
the elementary capacitive structures in order to
produce elementary capacitors.
The capacitors thus produced are advantageously
17- 2~7~8~
~nmrnnF~l~tS with very small volume, the capacity per
unit volume of which may reàch, for example, 20, 000 nF
per mm3.
Figure 5 represents the sectional view of a
5 resistive 8tructure obtained according to the
invention .
As mentioned above, the invention generally
relates to a process making it possible to deposit a
succession of dielectric layers and conducting polymer
10 layers on a rotating substrate.
The invention thus relates to a f abrication
process making it possible to produce a resistive
structure as represented in Figure 5. Like the
capacitive structure described above, the resistive
15 structure according to the invention is in the form of
a set of N elementary resistive structures Ri (i = 1,
2, ..., N) in parallel, separated from one another by
wel l s Pi ( i = 1 , 2 , . . ., N- l ) . Each elementary
resistive structure Ri has its side walls metallized
2 0 The succession of masks used to def ine such a structure
is then adjusted in such a way that the side walls of
the same elementary resistive structure are
electrically connected together and the side walls of
two neighbouring elementary structures are connected
together by at least one conducting polymer deposit.
As for the case of the capacitors described
above, the wells Pi are as nlany zones as make it
possible to facilitate the cutting of the resistive
structure into elementary resistive structures.
3 0 The process according to the invention then
comprises a step of cutting the elementary resistive
structures into elementary resistors.
According to the invention, the side walls of
each elementary resistive structure are conductive It
is then sufficient either to pass each el~ -~t~y
resistive structure through a molten alloy wave or to
deposit a soldering alloy or ~301dering cream on the
side walls of each elementary resistive structure in
order to produce the connections of the future
3 - 21 77~8~
resistors .
Figure 6 represents the sectional view of a
resistive and capacitive structure obtained according
to the invention. For reasons of convenience, only one
5 elementary resistive structure R and one elementary
r~r~r~;ve structure S have been represented. However,
the invention relates to structures composed of a
plurality of elementary capacitive structures and a
plurality of elementary resistive structures. The
10 elementary capacitive structure S is separated from the
elementary resistive structure R by a well Pu.
Figure 7 is a sectional view of a masking
device u6ed according to the invention.
An enclosure 25 contains oil in the liquid
15 phase 24. Heating elements (not reprPsented in the
figure) allow the oil to partially evaporate. The oil
in the vapour phase f ills the notches 27 of the
printing roller 26 integral with the enclosure 25. The
width of the notches 27 defines the width o the
20 masking zones such as 11 and 12 defined above. The
distance between two neighbouring notches def ines the
distance between the axes of two neighbouring masking
zones. The printing roller ls fixed. The oil is
deposited on the substrate which rotates at the angular
25 velocity n of the drum 2. This deposition is due to the
condensation of the oil on the substrate, the
temperature of which is lower than the temperature of
the oil.
In order to ensure optimum conditions fo~ the
3 0 deposition of oil on the substrate, the distance
6eparating the printing roller 26 from the substrate is
kept virtually constant, for example of the order of a
few microns, throughout the process. The quantity of
oil transferred is controlled by adjus~ing the heating
35 power of the heating elements.
In general, all ty~oes of patterns are
envisageable for producing the notches which define a
given mask.
The notches 27 which define a given mask are
- 19 - 2177g~
preferably aligned on the same generatrics of the
printing roller 26. It is then possible to define the
masking patterns o different masks on the same
printing roller. The masking patterns to be placed in
5 front of the_ substraté are then chosen simply by
rotating the printing roller.
Similarly, the notches 2'7 which define a given
mask can be adjugted in such a way that a structure
produced according to the process of the invention
10 consists of a succession of alternately capacitive and
resistive elementary structures. The subsequent cutting
of such a structure can then advantageously lead to the
fabrication of components consisting of a resistor and
a capacitor ~ n series .
The connections of such components are produced
in the same way as that described above for the
capacitors or the resistors.
Advantageously, a printing roller 26 can also
be used as a support for various cutting elements, so
20 as to make it possible to cut the capacitor structure
and/or the resistive structure into elementary
structures.
According to the process of the invention, the
roller 26 can also make it possible to mark various
25 logos on the components.
According to the prior art, discharge plasma-
enhanced depositions are carried out on heated
substrates. An advantage of deposition by flowing
remote cold plasma according to the invention is that
30 it is not necessary to heat the substrate on which the
dielectric and conducting deposits are made. The
mechanical characteristics of the substrate are
there~ore~ not degraded, and the reliability of the
con~ron~n~.~ produced by the process of the invention is
35 improved in comparison with that of components produced
by proce~ses of the prior art.
