JP2009182146A - Manufacturing method of insulating sheet substrate, and manufacturing method of multilayer circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the manufacturing method of an insulating sheet substrate in which working precision of a pattern formed using droplets is improved, and the manufacturing method of a multilayer circuit board. <P>SOLUTION: A carrier sheet 45 is used which has, on a coating surface 45a, a pattern 45P for transfer corresponding to a liquid pattern, ceramic slurry CS is supplied onto the coating surface 45a of the carrier sheet 45 to form the drawing surface of a ceramic green sheet 32 on the coating surface 45a of the carrier sheet 45, and the ceramic green sheet 32 is peeled from the carrier sheet 45 to form a protective pattern enclosing a drawing area on the drawing surface of the ceramic green sheet 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an insulating sheet substrate and a method for manufacturing a multilayer circuit board.

  Low temperature co-fired ceramics (LTCC) technology enables the simultaneous firing of ceramic powder and metal fine particles, and thus can implement an element-embedded substrate incorporating various passive elements between ceramic layers. In the system-on-package (SOP) mounting technology, this element-embedded substrate (hereinafter simply referred to as an LTCC multilayer substrate) is used in order to reduce the parasitic effects that occur in the combination of electronic components and surface-mounted components. Manufacturing methods related to this have been intensively developed.

  In the manufacturing method of the LTCC multilayer substrate, a drawing process of drawing patterns such as passive elements and wirings on a plurality of green sheets containing ceramic powder and an organic binder, and a lamination process of laminating a plurality of green sheets having the patterns And a firing step of firing the laminate at once.

In the drawing process, in order to increase the density of various patterns, a so-called ink jet method has been proposed in which a liquid containing conductive fine particles (hereinafter simply referred to as conductive ink) is discharged as fine droplets. (For example, Patent Document 1). The ink jet method uses droplets of several picoliters to several tens of picoliters and changes the ejection position of the droplets, thereby enabling a fine pattern and a narrow pitch.
JP 2005-57139 A

  FIG. 10A is a plan view of the pattern 101 in the drawing process, and FIG. 10B is a cross-sectional view taken along line AA of FIG. Fig.11 (a) is a top view of the pattern 101 in a lamination process, FIG.11 (b) is AA sectional drawing of Fig.11 (a).

  The conductive ink used in the ink jet method is a dispersion system of conductive fine particles, and the particle diameter of the conductive particles is generally from several nanometers to several tens of nanometers. As shown in FIGS. 10A and 10B, a pattern 101 is formed in the drawing area 104 on the main surface (drawing surface 103a) of the green sheet 103 through a drawing process. The pattern 101 is an aggregate of the conductive fine particles 102 and keeps the state until it is fired by the firing process.

  In the laminating step, the plurality of green sheets 103 are pressed with a predetermined pressure so as to sandwich the pattern 101. The conductive fine particles 102 before firing are easily crushed by the pressing during lamination as shown in FIGS. 11 (a) and 11 (b) because the adhesion strength with the green sheet 103 and the bonding strength between the particles are weak. End up. As a result, in the stacking step, the pattern 101 is deformed so as to extend along the drawing surface 103a of the green sheet 103, and protrudes from a desired drawing region 104 (two-dot chain line in FIGS. 10 and 11). There was a problem of short-circuiting due to contact with the pattern 101.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to produce an edge sheet substrate with improved processing accuracy of a pattern formed using droplets, and to produce a multilayer circuit board. Is to provide a method.

  The method for manufacturing an insulating sheet substrate according to the present invention includes a main surface that receives liquid droplets made of a liquid material containing conductive fine particles, and the main surface is made of the liquid material by receiving the liquid droplets on the main surface. A method for manufacturing an insulating sheet substrate that enables a liquid pattern to be formed, wherein a transfer substrate on which a concave transfer pattern corresponding to the liquid pattern is formed is used, and a sheet material is formed on the surface of the transfer substrate. To form the main surface of the insulating sheet substrate on the surface of the transfer base material, and to peel the insulating sheet substrate from the transfer base material, so that the outside of the liquid pattern formation region on the main surface Further, a convex protective pattern corresponding to the liquid pattern is formed.

  According to the method for manufacturing an insulating sheet substrate in the present invention, a convex protective pattern corresponding to the liquid pattern can be formed when the main body of the insulating sheet substrate is formed. Therefore, according to this method for manufacturing an insulating sheet substrate, the protective pattern protrudes outside the liquid pattern, so that the pattern made of conductive fine particles can be prevented from being crushed. Therefore, according to this method for manufacturing an insulating sheet substrate, the processing accuracy of a pattern formed using droplets can be improved.

The method for manufacturing the insulating sheet substrate may be a plurality of convex portions in which the protective pattern is discretely disposed outside the liquid pattern forming region.
According to this method for manufacturing an insulating sheet substrate, since the protective patterns are arranged in a discrete manner, the degree of freedom in designing the liquid pattern can be ensured. As a result, even in a pattern having a complicated shape, the processing accuracy can be improved.

  In this method of manufacturing an insulating sheet substrate, the main surface of the insulating sheet substrate is virtually divided into a plurality of lattices for defining whether or not to discharge the droplets, and each of the plurality of convex portions May be selectively disposed on the lattice.

  According to this method for manufacturing an insulating sheet substrate, since a plurality of protective patterns are arranged for each lattice that regulates the ejection and non-ejection of droplets, the degree of freedom in designing a liquid pattern can be further improved. . As a result, even in a pattern having a complicated shape, the processing accuracy can be improved.

  In this method of manufacturing an insulating sheet substrate, the sheet material is a slurry containing ceramic particles and a binder, the insulating sheet substrate is a ceramic green sheet, and the slurry is applied to the surface of the transfer substrate. The main surface of the ceramic green sheet may be formed on the surface of the transfer substrate by drying the coating film made of the slurry.

  According to this method for manufacturing an insulating sheet substrate, since the protective pattern is formed using the fluid, the shape of the protective pattern more reliably becomes a shape corresponding to the liquid pattern. Therefore, this method for manufacturing an insulating sheet substrate can more reliably improve the processing accuracy of the liquid pattern in the ceramic green sheet because the shape of the protective pattern can be formed in a shape corresponding to the liquid pattern.

The method for manufacturing the insulating sheet substrate may be a carrier sheet on which the transfer base material conveys the coating film.
According to this method for manufacturing an insulating sheet substrate, a protective pattern is formed on a carrier sheet that conveys a coating film, so that the shape of the protective pattern can be more reliably compared to the case where a transfer substrate is used separately. It can be formed in a shape corresponding to the liquid pattern.

  The method for producing a multilayer circuit board according to the present invention comprises a step of forming an insulating sheet substrate made of an insulating sheet material, and a droplet made of a liquid containing conductive fine particles on the main surface of the insulating sheet substrate. A step of drawing a liquid pattern made of the liquid on the surface of the insulating sheet substrate, a step of drying the liquid pattern to form a dry pattern, and a plurality of the insulating sheet substrates having the dry pattern. Forming a multilayer circuit board by laminating and press-bonding, wherein the step of forming the insulating sheet substrate includes a concave transfer pattern corresponding to the liquid pattern Is used to form a main surface of the insulating sheet substrate on the surface of the transfer substrate by supplying a sheet material to the surface of the transfer substrate. The step of forming the convex protective pattern corresponding to the liquid pattern on the outside of the liquid pattern forming region on the main surface by peeling the insulating sheet substrate from the base material and drawing the main pattern The liquid pattern is drawn by discharging the droplets onto the surface formation region.

  According to the method for manufacturing a multilayer circuit board in the present invention, a convex protective pattern corresponding to the liquid pattern can be formed when the main body of the insulating sheet substrate is formed. Therefore, according to this method for manufacturing a multilayer circuit board, the protective pattern protrudes outside the liquid pattern, so that the pattern made of conductive fine particles can be prevented from being crushed. Therefore, according to this method for manufacturing a multilayer circuit board, the processing accuracy of a pattern formed using droplets can be improved.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a circuit module having a multilayer circuit board. In FIG. 1, a circuit module 10 includes a low temperature co-fired ceramics (LTCC) multilayer substrate 11 as a multilayer circuit substrate, and a semiconductor chip 12 connected to the LTCC multilayer substrate 11.

  The LTCC multilayer substrate 11 has a plurality of LTCC substrates 13 stacked. Each LTCC substrate 13 is a sintered body of a green sheet and has a thickness of several tens of micrometers to several hundreds of micrometers. Between the layers of each LTCC substrate 13, various internal elements 14 such as a resistance element, a capacitive element, and a coil element, and an internal wiring 15 electrically connected to each internal element 14 are incorporated. Are formed with via wirings 16 each having a stacked via structure or a thermal via structure. The internal element 14 and the internal wiring 15 are each a sintered body of conductive fine particles, and are formed by an inkjet method using a liquid material containing conductive fine particles.

  Next, a method for manufacturing the LTCC multilayer substrate 11 will be described with reference to FIGS. FIG. 2 is a flowchart showing a manufacturing method of the LTCC multilayer substrate 11, and FIG. 3 is a process diagram showing a drawing process in the manufacturing method of the LTCC multilayer substrate 11. 4A is a plan view showing a drawing surface 32a of the ceramic green sheet 32, and FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A. FIG. 5 is a process diagram showing a lamination process in the manufacturing method of the LTCC multilayer substrate 11.

  In FIG. 2, in the manufacturing method of the LTCC multilayer substrate 11, first, a drawing process (step S <b> 11) for drawing a liquid pattern on a green sheet as an insulating sheet substrate that is a precursor of the LTCC substrate 13 is executed. Next, a drying step (Step S12) for drying the liquid pattern, a lamination step (Step S13) for laminating a plurality of green sheets, and a firing step (Step S14) for firing the laminate are sequentially performed.

In FIG. 3, a droplet discharge device 20 is used in the drawing process. The droplet discharge device 20
A stage 21 that holds an ejection target, an ink tank 22 that stores a liquid containing conductive fine particles (hereinafter simply referred to as conductive ink Ik), and a droplet D of conductive ink Ik from the ink tank 22. And a discharge head 23 that discharges to a discharge target.

  The conductive ink Ik is a dispersion system of the conductive fine particles S in which the conductive fine particles S are dispersed in the dispersion medium F. The viscosity of the conductive ink Ik is adjusted to 20 cP or less in order to enable the discharge of minute droplets D. Yes. The conductive fine particle S is a fine particle having a particle size of several nanometers to several tens of nanometers. For example, gold, silver, copper, platinum, palladium, rhodium, osmium, ruthenium, iridium, iron, tin, cobalt, nickel, A metal such as chromium, titanium, tantalum, tungsten, or indium, or an alloy thereof can be used. The dispersion medium F may be any material that uniformly disperses the conductive fine particles S. For example, water, an aqueous solution containing water as a main component, or an organic solvent containing an organic solvent such as tetradecane as a main component can be used. .

  The ejection head 23 includes a cavity 24 that communicates with the ink tank 22, a nozzle 25 that communicates with the cavity 24, and a pressure generating element 26 that is coupled to the cavity 24. The cavity 24 receives the conductive ink Ik from the ink tank 22 and supplies the conductive ink Ik to the nozzle 25. The nozzle 25 is a nozzle having an opening of several tens of micrometers, and forms a gas-liquid interface (meniscus) in the opening using the conductive ink Ik from the ink tank 22. The pressure generating element 26 is a piezoelectric element or a capacitive element that changes the volume of the cavity 24, or a resistance heating element that changes the temperature of the cavity 24, and generates a predetermined pressure inside the cavity 24. When the pressure generating element 26 is driven, the nozzle 25 vibrates the meniscus made of the conductive ink Ik and discharges the conductive ink Ik into droplets D of several picoliters to several tens of picoliters.

  The discharge target in the present embodiment is a laminated sheet 33 including a support sheet 31 and a ceramic green sheet 32 laminated on the support sheet 31. The support sheet 31 is a sheet for supporting the ceramic green sheet 32 in the drawing process and the drying process, and is made of a polymer material having releasability from the ceramic green sheet 32 and excellent in mechanical resistance in the drawing process. As the support sheet 31, for example, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyethylene film, or a polypropylene film can be used.

  The ceramic green sheet 32 is a sheet made of a glass ceramic composition containing glass ceramic powder, an organic binder, and the like. The film thickness of the ceramic green sheet 32 is several tens of micrometers when the capacitor element is formed as the internal element 14, and the other layers are formed with a thickness of 100 to 200 micrometers.

The glass ceramic powder is a powder having an average particle diameter of 0.1 to 5 micrometers. For example, a glass composite ceramic obtained by mixing borosilicate glass with ceramic powder such as alumina and forsterite can be used. As the glass ceramic powder, a crystallized glass ceramic using a crystallized glass of ZnO—MgO—Al ₂ O ₃ —SiO ₂ type, BaO—Al ₂ O ₃ —SiO ₂ type ceramic powder, Al ₂ O ₃ — Non-glass ceramics using CaO—SiO ₂ —MgO—B ₂ O ₃ ceramic powder or the like may be used.

The organic binder is a polymer material that functions as a binder for the glass ceramic powder and can be easily removed by decomposition in the firing step. As the organic binder, for example, an organic binder resin such as butyral, acrylic, or cellulose can be used. As the acrylic organic binder resin, for example, a homopolymer of a (meth) acrylate compound such as alkyl (meth) acrylate, alkoxyalkyl (meth) acrylate, polyalkylene glycol (meth) acrylate, cycloalkyl (meth) acrylate, or the like is used. be able to. In addition, the acrylic organic binder resin may be a copolymer obtained from two or more of the (meth) acrylate compounds, or other copolymerizable monomers such as (meth) acrylate compounds and unsaturated carboxylic acids. The resulting copolymer can be used. The organic binder may contain a plasticizer such as adipic acid ester plasticizer, dioctyl phthalate (DOP), dibutyl phthalate (DBP) phthalic acid ester plasticizer, glycol ester plasticizer.

  A circular hole or a conical hole (hereinafter, simply referred to as a via hole 32h) having a hole diameter of several tens to several hundreds of micrometers is formed through the ceramic green sheet 32 by punching or laser processing. The via hole 32h is filled with a conductive material such as silver, gold, copper, or palladium in the previous step by a squeegee method using a conductive paste or an inkjet method using a conductive ink.

  4A and 4B, a protective pattern 32P as a protruding portion protruding from the drawing surface 32a is formed on the upper surface of the ceramic green sheet 32 (hereinafter simply referred to as the drawing surface 32a). The protection pattern 32P is a convex pattern on the drawing surface 32a, and has a shape corresponding to the liquid pattern formed in the drawing process.

  The protective pattern 32P in the present embodiment is formed outside a liquid pattern region (two-dot chain line in FIG. 4A: hereinafter simply referred to as a drawing region PS as a forming region) formed in the drawing process. Yes. The protective pattern 32P is formed at a position away from the drawing area PS by a predetermined distance so as to surround the drawing area PS. The protective pattern 32P is separated from the drawing area PS by a predetermined distance, thereby suppressing contact with the droplets D ejected to the drawing area PS. When the conductive ink Ik has high wettability with respect to the protective pattern 32P, the conductive ink Ik protrudes from the drawing region PS by the distance between the conductive ink Ik and the protective pattern 32P. Can be avoided. When the protective pattern 32P is formed along the outer edge of the drawing region PS, the conductive ink Ik flows along the protective pattern 32P, and thus the conductive ink Ik is likely to be unevenly distributed in the drawing region PS. . That is, the conductive ink Ik tends to protrude from the drawing area PS, and there is a possibility of causing a short circuit between the adjacent drawing areas PS.

  In the drawing process, the laminated sheet 33 and the ejection head 23 move relatively along the surface direction of the drawing surface 32a, and a plurality of droplets D from the nozzles 25 land on the drawing region PS on the drawing surface 32a. The plurality of droplets D that land on the drawing area PS are united inside the drawing area PS, and form a liquid pattern PL surrounded by the protective pattern 32P on the drawing surface 32a.

  In the drying process, the laminated sheet 33 after the drawing process is carried into a drying apparatus such as a drying furnace and heated to the drying temperature in a state having the liquid pattern PL. As a result, most of the dispersion medium F contained in the liquid pattern PL is evaporated, and the dry pattern PD made of the aggregate of the conductive fine particles S is formed so as to be surrounded by the protective pattern 32P. If the drying temperature is excessively high, the support sheet 31 and the ceramic green sheet 32 are thermally deformed, and the positional accuracy with the other laminated sheets 33 during the lamination process is impaired. Therefore, the drying temperature is, for example, 40 ° C. to 80 ° C., and is appropriately selected according to the composition of the laminated sheet 33 and the composition of the conductive ink Ik so as to ensure positional accuracy during the lamination process.

In FIG. 5, in the laminating step, first, the support sheet 31 is peeled off from each of the plurality of laminated sheets 33. Each of the plurality of ceramic green sheets 32 is sequentially stacked in a state having the dry pattern PD to form a stacked body including the plurality of ceramic green sheets 32. The laminated body composed of the plurality of ceramic green sheets 32 is pressure-bonded by using an isostatic pressing method or the like. At this time, each dry pattern PD can suppress the stress deformation associated with the pressure bonding by the amount surrounded by the protection pattern 32P. That is, since each dry pattern PD can suppress crushing along the surface direction of the ceramic green sheet 32, it is possible to prevent disconnection, short circuit between lines, and the like due to crimping.

  In the firing step, the laminate obtained in the lamination step is carried into a predetermined firing furnace and fired. The firing temperature is, for example, 800 ° C. to 1000 ° C., and is appropriately changed according to the composition of the ceramic green sheet 32. In the firing step, the organic binder is decomposed and removed from the ceramic green sheet 32. Further, the glass ceramic powder in the ceramic green sheet 32 is sintered together, and the conductive fine particles S in the dry pattern PD are sintered together. Then, the space between the dry pattern PD and the protective pattern 32P is reduced or disappears according to the difference between the shrinkage rate of the ceramic green sheet 32 and the shrinkage rate of the dry pattern. In addition, when using Cu as dry pattern PD, in order to prevent the oxidation of Cu, baking in a reducing atmosphere is preferable. When silver, gold, platinum, palladium or the like is used, it may be fired in the air. In the firing step, the laminate may be fired while being pressed at a pressure smaller than the hydrostatic pressure in the lamination step. According to this, the flatness of the LTCC multilayer substrate 11 is improved, and warpage and peeling of each ceramic green sheet 32 can be prevented.

  Next, a method for manufacturing the ceramic green sheet 32 will be described with reference to FIGS. FIG. 6 is a diagram schematically showing a green sheet manufacturing apparatus, and FIG. 7 is a plan view showing a coated surface of the carrier sheet.

  In the method for manufacturing the ceramic green sheet 32, first, a coating process for forming a coating film that is a precursor of the ceramic green sheet 32 is executed. Next, a drying process for drying the coating film and a peeling process for peeling the dried coating film from the carrier sheet are sequentially performed.

  In FIG. 6, the ceramic green sheet manufacturing apparatus 40 includes a transport system 41, a coating unit 42, a drying unit 43, and a peeling unit 44. The transport system 41 includes a pair of transport rollers 46 for transporting a carrier sheet 45 as a transfer substrate, and a pair of support rollers 47 for supporting the carrier sheet 45. The conveyance system 41 feeds the carrier sheet 45 from one conveyance roller 46 toward the support roller 47, and the carrier sheet 45 stretched between the pair of support rollers 47 is wound around the other conveyance roller 46 in order. That is, the conveyance system 41 conveys the carrier sheet 45 fed from the pair of conveyance rollers 46 in the order of the coating unit 42, the drying unit 43, and the peeling unit 44.

  In FIG. 7, a carrier sheet 45 is a flexible sheet formed in a strip shape made of polyethylene terephthalate or the like. A plurality of transfer areas 45S are virtually divided on the surface of the carrier sheet 45 (hereinafter simply referred to as a coating surface 45a), and each transfer area 45S surrounds a virtual area IS corresponding to the drawing area PS. Thus, a transfer pattern 45P is formed. Each transfer pattern 45P is a concave pattern on the coating surface 45a, and is formed to have approximately the same size as the protective pattern 32P used in the drawing process. When the transfer pattern 45P receives the slurry from the application portion 42, the slurry is applied to the entire outer surface of the transfer pattern 45P.

The application unit 42 includes a slurry tank 42a and an application head 42b. The slurry tank 42a accommodates therein a ceramic slurry CS obtained by slurrying the glass ceramic composition. The slurry tank 42a supplies the ceramic slurry CS to be stored to the coating head 42b with a predetermined pressure. The coating head 42 b has a coating port that is separated from the coating surface 45 a of the carrier sheet 45 by a predetermined distance. The coating head 42b is a slurry tank 4
The ceramic slurry CS from 2a is received, and the ceramic slurry CS from the slurry tank 42a is applied to the application surface 45a of the carrier sheet 45 to form a coating film FL having a predetermined thickness.

  The drying unit 43 has a heater for heating the coating film FL formed on the coating surface 45 a of the carrier sheet 45. The drying unit 43 dries the coating film FL transported from the coating unit 42 side to a state where it can be handled. The peeling unit 44 has a cutting blade or the like for cutting the dried coating film FL, and adsorbs the cut coating film FL (ceramic green sheet 32) to peel it from the carrier sheet 45.

  That is, the ceramic green sheet manufacturing apparatus 40 drives the coating unit 42 and the drying unit 43 to form the coating film FL made of the ceramic slurry CS on each transfer region 45S, and drives the peeling unit 44. Then, the coating film FL is peeled off from each transfer region 45S. Thus, the ceramic green sheet manufacturing apparatus 40 transfers the transfer pattern 45P to the lower surface of the coating film FL, and forms the drawing surface 32a and the protective pattern 32P on the lower surface of the coating film FL. The laminated sheet 33 can be formed by attaching the support sheet 31 to one side surface of the ceramic green sheet 32 that faces the protective pattern 32P.

Next, the effect of 1st embodiment comprised as mentioned above is described below.
(1) In the first embodiment, the ceramic slurry CS is supplied to the application surface 45a using the carrier sheet 45 on which the transfer pattern 45P corresponding to the liquid pattern PL is formed on the application surface 45a. Then, the drawing surface 32a of the ceramic green sheet 32 is formed on the coating surface 45a, and the coating film FL is peeled off from the carrier sheet 45.

  Therefore, according to the method for manufacturing the ceramic green sheet, the protective pattern 32P protruding from the drawing surface 32a can be formed so as to surround the drawing region PS. As a result, in the laminating step, the dry pattern PD made of the conductive fine particles S is surrounded by the protective pattern 32P, so that the dry pattern PD can be prevented from being crushed. As a result, the processing accuracy of the internal element 14 and the internal wiring 15 in the LTCC multilayer substrate 11 can be improved.

  (2) Moreover, since the protective pattern 32P is formed using the ceramic slurry CS that is a fluid, the shape of the protective pattern 32P is more reliably changed to the shape corresponding to the transfer pattern 45P, that is, the liquid pattern PL. It becomes the shape according to. Therefore, by using this method for manufacturing the ceramic green sheet 32, the processing accuracy of the internal element 14 and the internal wiring 15 in the LTCC multilayer substrate 11 can be further improved.

  (3) In addition, since the protective pattern 32P is formed on the carrier sheet 45 that conveys the coating film FL, the outer edge of the ceramic green sheet 32 and the protective pattern 32P are smaller than when a transfer substrate is used separately. It is possible to improve the positional consistency of the. As a result, the processing accuracy of the internal element 14 and the internal wiring 15 in the LTCC multilayer substrate 11 can be further improved.

(4) The protection pattern 32P in the first embodiment is formed at a position away from the drawing area PS by a predetermined distance so as to surround the drawing area PS. Therefore, the protection pattern 32P can suppress contact between the droplet D discharged to the drawing area PS and the protection pattern 32P, and can prevent the conductive ink Ik from protruding from the drawing area PS. As a result, since the processing accuracy of the liquid pattern PL can be improved in the drawing process, the processing accuracy of the internal element 14 and the internal wiring 15 in the LTCC multilayer substrate 11 can be further improved.
(Second embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the protection pattern 32P in the first embodiment is changed. Therefore, in the following, the changes will be described in detail. Fig.8 (a) is the top view which looked at the lamination sheet 33 of 2nd embodiment from the drawing surface 32a, FIG.8 (b) is AA sectional drawing of Fig.8 (a). Fig.9 (a) is a top view which shows the lamination sheet 33 by which liquid pattern PL was drawn, FIG.9 (b) is AA sectional drawing of Fig.9 (a).

  In FIG. 8, on the drawing surface 32a of the ceramic green sheet 32, a plurality of dot pattern lattices 50 that prescribe ejection or non-ejection of droplets D are virtually divided. Each dot pattern lattice 50 is a lattice partitioned by the discharge pitch of the droplets D, and a desired pattern is drawn on the drawing surface 32a by discharging the droplets D to each of the selected dot pattern lattices 50. Is done.

  On the drawing surface 32a of the ceramic green sheet 32, a plurality of protective patterns 32P as convex portions are arranged discretely. Each of the plurality of protection patterns 32P is formed in a column shape protruding from the drawing surface 32a, and is disposed inside a dot pattern grid 50 (hereinafter simply referred to as a selection grid) that is selected in advance.

  In FIG. 9, a drawing region PS (region with gradation) is partitioned on the drawing surface 32 a of the ceramic green sheet 32 in order to discharge droplets D. The drawing area PS is an area composed of a plurality of dot pattern grids 50, and is set to an area of the protection pattern 32P, that is, an area excluding the selected grid. FIG. 9 shows a state in which the liquid pattern PL is formed in the drawing area PS.

  In the drawing process, the laminated sheet 33 and the ejection head 23 move relative to each other along the surface direction of the drawing surface 32a, and a plurality of droplets D from the nozzles 25 land on the respective dot pattern lattices 50 in the drawing region PS. The plurality of liquid droplets D that land on the drawing area PS are united inside the drawing area PS to form a liquid pattern PL surrounded by discrete protective patterns 32P.

  At this time, since the protection pattern 32P is disposed inside the dot pattern lattice 50 and discretely, the shape and size of the drawing region PS are not greatly affected. In other words, since the protection pattern 32P enables selection of the size and shape of the drawing area PS, the protection pattern 32P can correspond to a plurality of drawing areas PS and can secure a degree of freedom in designing the drawing area PS.

  In the stacking step, as in the first embodiment, each of the plurality of ceramic green sheets 32 is sequentially stacked in a state having the dry pattern PD, and a stacked body including the plurality of ceramic green sheets 32 is formed. The laminated body composed of the plurality of ceramic green sheets 32 is pressure-bonded by using an isostatic pressing method or the like. At this time, the pressing force received by the dry pattern PD is dispersed by the discrete protective patterns 32P. As a result, the dry pattern PD can be prevented from being crushed along the surface direction of the ceramic green sheet 32, so that disconnection, short circuit between lines, and the like associated with crimping can be prevented.

  In the method of manufacturing the ceramic green sheet 32, the carrier sheet 45 on which the concave transfer pattern 45P corresponding to the protection pattern 32P is formed is used as in the first embodiment. When the transfer pattern 45P receives the slurry from the application portion 42, the slurry is applied to the entire outer surface of the transfer pattern 45P. Thereby, columnar protection patterns 32P protruding from the drawing surface 32a are discretely formed over the entire drawing surface 32a.

Next, the effect of 2nd embodiment comprised as mentioned above is described below.
(5) The protection patterns 32P in the second embodiment are discretely arranged outside the drawing area PS. Therefore, since the protective patterns 32P are arranged in a discrete manner, the degree of freedom in design can be ensured with respect to the shape and size of the drawing region PS. As a result, even in a pattern having a complicated shape, the processing accuracy can be improved.

  (6) In the second embodiment, the drawing surface 32a is virtually divided into a plurality of dot pattern lattices 50 that define whether or not to discharge the droplets D, and the protection pattern 32P is selected for each dot pattern lattice 50, respectively. Are arranged. Therefore, since the protection pattern 32P is arranged for each selected dot pattern grid 50, the dot pattern grid 50 can obtain the positional consistency between the protection pattern 32P and the drawing area PS. As a result, the processing accuracy can be improved even in a pattern having a complicated shape.

In addition, you may change the said embodiment as follows.
In the above embodiment, the transfer substrate is embodied in the carrier sheet 45. For example, a substrate having the transfer pattern 45P may be used as the transfer substrate. That is, the transfer substrate may be any substrate that has a concave transfer pattern on the surface and forms a protective pattern 32P corresponding to the transfer pattern on the surface by receiving the sheet material.

  In the first embodiment, the protection pattern 32P is formed outside the liquid pattern PL (drawing area PS) and surrounding the entire drawing area PS. However, the protection pattern 32P may be configured to surround a part of the drawing area PS. For example, the protective pattern 32P may have a configuration in which the line width is relatively narrow and only the drawing area PS of the isolated liquid pattern PL is surrounded. According to this, it is possible to reliably protect patterns that are easily deformed (easy to be crushed) during the stacking process, and it is possible to reduce the number of protective patterns 32P. That is, the protection pattern 32P may be a shape corresponding to the size, shape, and pitch of the liquid pattern PL.

  The protection pattern 32P in the second embodiment is discretely arranged outside the drawing area PS. The protection pattern 32P is not limited to this, and may have a configuration in which the line width is relatively thin and the protection pattern 32P is intensively disposed so as to surround only the drawing region PS of the isolated liquid pattern PL. Even in this configuration, it is possible to reliably protect patterns that are easily deformed during the stacking process, and to reduce the number of protection patterns 32P.

  Each protection pattern 32P in the second embodiment is formed inside one dot pattern grid 50, respectively. Not limited to this, the protection pattern 32 </ b> P may have a shape straddling a plurality of dot pattern lattices 50. In other words, the protection pattern 32P may be configured to be discretely arranged in the region partitioned by the dot pattern grid 50. Also in this configuration, the positional consistency between the protection pattern 32P and the drawing area PS is obtained by the dot pattern grid 50, so that the degree of freedom in designing the drawing area PS can be ensured.

  In the above embodiment, when the fluidity of the droplet D in the drawing area PS is low, the protective pattern 32P may be formed along the outer edge of the drawing area PS. According to this, since the uneven distribution of the conductive ink Ik in the drawing area PS is difficult to be caused, the protrusion of the conductive ink Ik from the drawing area PS is suppressed, and between the drawing area PS and the liquid pattern PL. The positional consistency of the is improved.

  In the above embodiment, the insulating sheet substrate is embodied as the ceramic green sheet 32. For example, a thermoplastic substrate (organic green sheet) made of polyimide resin or the like may be used as the insulating sheet substrate. The insulating sheet substrate receives droplets made of a liquid containing conductive fine particles. Any insulating sheet capable of forming a liquid pattern may be used.

  In the above embodiment, the multilayer circuit board is embodied as an LTCC multilayer board. For example, the multilayer circuit board may be a multilayer board in which thermoplastic substrates made of polyimide resin or the like are laminated.

Sectional drawing which shows a circuit module. The flowchart which shows the manufacturing method of a ceramic multilayer substrate. Process drawing which shows a drawing process. (A), (b) is the top view and sectional drawing which show the protection pattern of 1st embodiment, respectively. Process drawing which shows a lamination process. The figure which shows the manufacturing apparatus of a green sheet typically. The top view which shows the carrier sheet of 1st embodiment. (A), (b) is the top view and sectional drawing which show the protection pattern of 2nd embodiment, respectively. (A), (b) is the top view and sectional drawing which show the drawing area | region of 2nd embodiment, respectively. It is a figure which shows the drawing process of the manufacturing method of the multilayer circuit board of a prior art example, Comprising: (a) is a top view of a green sheet, (b) is sectional drawing of a green sheet. It is a figure which shows the lamination process of the manufacturing method of the multilayer circuit board of a prior art example, Comprising: (a) is a top view of a green sheet, (b) is sectional drawing of a green sheet.

Explanation of symbols

  CS: ceramic slurry as sheet material, D: droplet, FL: coating film, Ik: liquid containing conductive fine particles, PD: dry pattern, PL: liquid pattern, 11: LTCC multilayer substrate as ceramic multilayer substrate, 32 ... Green sheet as an insulating sheet substrate, 32a ... Drawing surface as a main surface, 32P ... Protective pattern constituting a convex portion, 45 ... Carrier sheet as a transfer substrate, 45a ... Coating as a surface of the transfer substrate Surface, 45P: Transfer pattern.

Claims (6)

An insulating sheet substrate having a main surface for receiving droplets made of a liquid containing conductive fine particles, and allowing the liquid pattern made of the liquid to be formed on the main surface by receiving the droplets on the main surface. A manufacturing method comprising:
Using a transfer substrate on which a concave transfer pattern corresponding to the liquid pattern is formed, a sheet material is supplied to the surface of the transfer substrate, and the main surface of the insulating sheet substrate is formed on the surface of the transfer substrate. Forming a convex protective pattern corresponding to the liquid pattern on the outside of the liquid pattern forming region on the main surface by forming a surface and peeling the insulating sheet substrate from the transfer base. A method for manufacturing an insulating sheet substrate. A method for producing an insulating sheet substrate according to claim 1,
The method for manufacturing an insulating sheet substrate, wherein the protective pattern is a plurality of convex portions discretely arranged outside the liquid pattern formation region. A method for manufacturing an insulating sheet substrate according to claim 2,
The main surface of the insulating sheet substrate is virtually divided into a plurality of grids for defining whether or not the liquid droplets are discharged, and each of the plurality of convex portions is selectively disposed on the grid. A method for manufacturing an insulating sheet substrate, characterized in that: It is a manufacturing method of an insulating sheet substrate given in any 1 paragraph of Claims 1-3,
The sheet material is a slurry containing ceramic particles and a binder,
The insulating sheet substrate is a ceramic green sheet;
An insulating sheet substrate characterized in that the main surface of the ceramic green sheet is formed on the surface of the transfer substrate by applying the slurry to the surface of the transfer substrate and drying the coating film made of the slurry. Manufacturing method. It is a manufacturing method of the insulating sheet substrate according to claim 4,
The method of manufacturing an insulating sheet substrate, wherein the transfer base material is a carrier sheet that conveys the coating film. Forming an insulating sheet substrate made of an insulating sheet material;
Drawing a liquid pattern made of the liquid material on the surface of the insulating sheet substrate by discharging droplets made of a liquid material containing conductive fine particles on the main surface of the insulating sheet substrate;
Drying the liquid pattern to form a dry pattern;
Forming a multilayer circuit board by laminating and press-bonding a plurality of the insulating sheet substrates having the dry pattern, and a method of manufacturing a multilayer circuit board,
The step of forming the insulating sheet substrate includes:
Using a transfer substrate on which a concave transfer pattern corresponding to the liquid pattern is formed, a sheet material is supplied to the surface of the transfer substrate, and the main surface of the insulating sheet substrate is formed on the surface of the transfer substrate. Forming a surface, and by peeling the insulating sheet substrate from the transfer base material, a convex protective pattern corresponding to the liquid pattern is formed outside the liquid pattern forming region on the main surface,
The drawing step includes
A method of manufacturing a multilayer circuit board, wherein the liquid pattern is drawn by discharging the droplets onto a formation region of the main surface.

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