JP4785945B2 - Unsintered multilayer ceramic substrate and method for manufacturing multilayer ceramic substrate - Google Patents

Description

  The present invention relates to an unsintered multilayer ceramic substrate and a method for manufacturing a multilayer ceramic substrate, and more particularly, when a multilayer ceramic substrate is manufactured by a non-shrink process, the protrusion of a via electrode connecting interlayer circuits is prevented and the periphery of the via hole The present invention relates to an unsintered multilayer ceramic substrate capable of suppressing the formation of pores and a method for manufacturing the multilayer ceramic substrate.

  In general, a multilayer ceramic substrate using a glass-ceramic has high design flexibility because an interlayer circuit having a three-dimensional structure can be realized. In recent years, the utilization of multilayer ceramic substrates has gradually increased in the market for high-frequency components that are becoming smaller and more functional. As the structure of the multilayer ceramic substrate is compounded and refined due to such a requirement, the design margin of the internal pattern and via structure gradually decreases, thereby suppressing the shrinkage in the lateral direction of the multilayer ceramic substrate. Is required.

  For this reason, mainly the method of suppressing the shrinkage | contraction of an xy direction by joining the soluble green sheet | seat of the hardly sinterable raw material which is not baked with the baking temperature of a ceramic substrate material to the one or both surfaces of a non-sintered ceramic laminated body. in use.

  However, in such a non-shrinking process method, in a multilayer ceramic substrate manufactured by laminating a plurality of ceramic green sheets, a plurality of via holes are formed for electrical connection of each interlayer circuit, and the inside is electrically conductive. Filled with conductive electrode material.

  At this time, since the via electrode is composed of the conductive metal powder, the organic binder, and the solvent, the volume of the via electrode shrinks during the firing process. Since the conductive metal powder has a larger volume shrinkage than ceramic, even if the conductive electrode material is filled 100% in volume before firing, the via hole and the via electrode are separated due to the difference in firing shrinkage rate. Large pores may be generated inside the via hole.

  In particular, in the non-shrinkage firing, the shrinkage-suppressing green sheet for the unsintered ceramic laminate has a low shrinkage-suppressing effect, so that it shrinks in the main surface direction, and the shrinkage in the thickness direction is reduced accordingly. As a result, the height of the via electrode after firing becomes higher than the via hole and protrudes to the outside, and pores may be generated around the via hole.

  In order to prevent pores around the via hole generated after firing as described above, if the via hole is filled with an excessive amount of conductive electrode material exceeding the volume of the via hole in the green state, the via hole was not filled during the lamination process or the pressurizing process. The conductive electrode material spreads around the entrance of the via hole, which may cause a short circuit between layers of the substrate or a defect such as a layer peeling phenomenon, resulting in poor product yield.

  FIG. 1 is a cross-sectional view showing a type of via electrode defect generated after non-shrinkage firing in the production of a non-shrink multilayer ceramic substrate according to a conventional method. Here, in the unsintered multilayer ceramic substrate, via holes are formed in the ceramic green sheets using punching and the like, and after filling the conductive electrode paste by a method such as screen printing, a plurality of such ceramic green sheets are laminated. It can be manufactured by post thermocompression bonding. At this time, a multilayer ceramic substrate is manufactured by joining shrinkage-suppressing green sheets composed of a hardly sinterable powder on both sides of an unsintered multilayer ceramic substrate and firing without shrinkage.

  Here, during the non-shrinkage firing, the portion where the via hole is formed in the ceramic green sheet is the conductive electrode paste, not the low-temperature co-fired ceramic material, because the continuity of the ceramic green sheet breaks and the material in contact with the shrinkage suppressing green sheet Therefore, the restraining force by the shrinkage-suppressing green sheet is weaker in and around the via hole in which the via electrode is buried than the side in contact with the ceramic green sheet. As a result, after firing, defects may be generated around the via hole due to a difference in shrinkage behavior in the main surface direction.

  Therefore, as illustrated in FIG. 1A, the conductive electrode paste buried in the via hole occupies 50% or more of the volume of the binder and various solvents. In some cases, the via electrode shrinks more than the ceramic green sheet after firing and a part of the via hole remains as pores A after firing. Furthermore, since the via electrode in the via hole is not strongly subjected to the restraining force by the shrinkage suppressing green sheet and contracts in the main surface direction, a huge pore A may be generated in the via hole. At the same time, as the via electrode shrinks in the peripheral direction, the shrinkage in the thickness direction becomes small, and therefore, the thickness becomes relatively thicker than that of the multilayer ceramic substrate after firing, and a defect that the via electrode protrudes B on the substrate occurs. Sometimes.

  As another type, as shown in FIG. 1B, by adding a non-sinterable powder that suppresses the shrinkage of the via electrode in the via hole, the shrinkage of the volume of the via electrode itself is suppressed. The generation of pores due to the shrinkage of the via electrode can be prevented, but the via electrode itself is not dense due to the organic binder and solvent added to the conductive electrode paste because the shrinkage of the via electrode is suppressed by the hardly sinterable powder. There is a disadvantage C.

  As another type, as shown in FIG. 1 (c), the metal powder content in the conductive electrode paste was increased in order to improve the generation of pores in the via hole. When the content of C is excessively increased, there is a limit that the content of the organic binder becomes too low and printability is lowered. Therefore, there is a problem that the via hole is sintered in a state D in which the conductive electrode paste is insufficiently filled.

US Patent Publication US63335077

  In order to solve the above-mentioned problems of the prior art, the object of the present invention is to use an aerosol deposition method that can form a high-density film in the production of a multilayer ceramic substrate through non-shrinkage firing. By forming a dense via electrode in a non-sintered multi-layer ceramic substrate and a multi-layer ceramic that can prevent the formation of pores inside the via hole due to the shrinkage of the via electrode after non-shrinkage firing, and suppress the protrusion of the via electrode It is to provide a method for manufacturing a substrate.

  In order to solve the above technical problem, an unsintered multilayer ceramic substrate according to one aspect of the present invention includes a ceramic green sheet in which at least one via hole is formed, and a polymer formed on one surface of the ceramic green sheet. A ceramic laminate having a resin layer and a via electrode supported by the polymer resin layer and formed of a conductive metal powder inside the via hole, and for shrinkage suppression disposed on one or both sides of the ceramic laminate A green sheet is included, and the height of the via electrode is lower than the height of the via hole.

  At this time, the height of the via electrode is 50% to 60% with respect to the height of the via hole in consideration of the contraction degree of the ceramic laminate, and the conductive metal powder includes Ag, Cu, Ni, Au and It is preferably any one of AgPd.

  The polymer resin layer is made of a thermally decomposable polymer that is decomposed and removed at a temperature lower than the temperature at which the ceramic laminate is sintered. The thermally decomposable polymer is made of polyvinyl alcohol (polyvinyl alcohol), polyvinyl butyral ( Polyvinyl butyral, vinyl resin including polyvinyl chloride, methyl cellulose, ethyl cellulose, cellulose poly ester including polyethyl acrylate, and polymethyl acrylate. (Polymethyl methacrylate: It is preferably at least one resin selected from the group consisting of an acrylic resin containing MMA).

The shrinkage-suppressing green sheet is composed of a hardly sinterable powder having a sintering temperature higher than the temperature at which the ceramic laminate is sintered, and the hardly sinterable powder is alumina (Al ₂ O ₃ ). , Cerium dioxide (CeO ₂ ), zincation (ZnO ₂ ), zirconia (ZrO ₂ ), magnesia (MgO), and boron nitride (BN) are preferred.

  Meanwhile, a method for manufacturing a multilayer ceramic substrate according to another aspect of the present invention includes the steps of forming at least one via hole and an electrode pattern in at least one ceramic green sheet among the plurality of ceramic green sheets, and forming the via hole. Bonding a polymer resin layer to one side of the ceramic green sheet, and applying a via electrode to a height lower than the height of the via hole using an aerosol deposition method in an area of the polymer resin layer exposed by the via hole; Forming a ceramic laminate by laminating the ceramic green sheets, and bonding a shrinkage-suppressing green sheet to one or both sides of the ceramic laminate to form an unsintered multilayer ceramic substrate. And sintering the green multilayer ceramic substrate. No.

  At this time, the step of forming the via electrode is a step of forming a dense via electrode made of only the conductive metal powder through high-speed jetting of the conductive metal powder by the aerosol deposition method, and the conductive metal powder is Ag. , Cu, Ni, Au, and AgPd.

  In addition, the step of forming the via electrode may include forming a pattern mask on the ceramic green sheet so as to open only the region exposed by the via hole in the polymer resin layer before spraying the conductive metal powder. The method may further include arranging.

  The height of the via electrode is determined by the shrinkage rate of the ceramic green sheet, and the height of the via electrode is a height corresponding to the sintered ceramic green sheet in consideration of the shrinkage rate of the ceramic green sheet. It is preferable that

  The polymer resin layer is composed of a thermally decomposable polymer that is decomposed and removed at a temperature lower than the temperature at which the ceramic green sheet is sintered, and the thermally decomposable polymer is made of polyvinyl alcohol, polyvinyl butyral, or polyvinyl chloride. It is preferably at least one resin selected from the group consisting of vinyl resins including methyl cellulose, ethyl cellulose, cellulose resins including hydroxyethyl cellulose, and acrylic resins including polyacrylic esters and polymethyl methacrylate.

  The step of removing the resultant shrinkage-suppressing green sheet from the sintered multilayer ceramic substrate further includes the step of removing the shrinkage-suppressing green sheet from the sintered multilayer ceramic substrate. It is preferably carried out by any one of lapping, sandblasting, washing with water and high-pressure spraying.

Further, the shrinkage-suppressing green sheet is made of a hardly sinterable powder having a sintering temperature higher than a temperature at which the ceramic laminate is sintered, and the hardly sinterable powder includes alumina (Al ₂ O ₃ ), It is preferably one of cerium (CeO ₂ ), zincation (ZnO ₂ ), zirconia (ZrO ₂ ), magnesia (MgO), and boron nitride (BN).

  According to the present invention, during non-shrinkage firing, a via electrode is formed after firing by forming a via electrode by densely filling a conductive metal powder into the via hole formed in the ceramic green sheet using an aerosol deposition method. Since there is almost no shrinkage of the electrode, generation of pores in the via hole due to contraction in the main surface direction of the via electrode and defect of the via electrode protrusion can be prevented, and there is an effect of preventing interlayer short-circuit or open defect caused by via filling.

FIGS. 1A to 1C are cross-sectional views showing types of via electrode defects generated after non-shrinkage firing in the production of a multilayer ceramic substrate according to a conventional method. 1 is a cross-sectional view illustrating an unsintered multilayer ceramic substrate in which via holes are formed during a manufacturing process of a multilayer ceramic substrate according to an embodiment of the present invention. It is sectional drawing according to process for demonstrating the manufacturing method of the multilayer ceramic substrate by one Embodiment of this invention. It is sectional drawing according to process for demonstrating the manufacturing method of the multilayer ceramic substrate by one Embodiment of this invention. It is sectional drawing according to process for demonstrating the manufacturing method of the multilayer ceramic substrate by one Embodiment of this invention. It is sectional drawing according to process for demonstrating the manufacturing method of the multilayer ceramic substrate by one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for a clearer description.

  The aerosol deposition method used in the present invention is a method in which a fine solid-phase powder is sprayed onto a substrate and a dense high-density thin film is formed on the substrate by collision energy between the solid-phase powder and the substrate.

  Explaining a specific aerosol deposition method, the carrier gas flows into the aerosol chamber containing the solid phase powder, and the fine solid phase powder floating in the aerosol chamber is placed on the carrier gas to the substrate in the vacuum deposition chamber. Spray through nozzle. A high-density film is formed on the substrate by the collision energy between the injected fine solid-phase powder and the substrate.

  At this time, according to the aerosol deposition method, the film formation rate reaches several μm per minute, which is significantly faster than the existing thin film process. Therefore, the film formation thickness can be easily adjusted from submicron thickness to several tens of microns. can do.

  In particular, since the speed of the ejected particles is as high as several hundred meters per second, and the fine solid phase powder has the corresponding kinetic energy, it will collide with the substrate, so the contact between the substrate and the film Thus, a very strong bond can be formed, and a film can be uniformly formed at a desired position regardless of the form of the substrate and the position of film formation.

  Accordingly, the present invention forms a via electrode by filling the inside of a via hole with only a conductive metal powder without using a binder or a solvent by using such an aerosol deposition method, thereby firing with strong collision energy at the time of filling. A dense via electrode with few pores is formed before, and there is almost no shrinkage of the volume during firing, and a via electrode completely filled in the via hole is formed even after firing through a behavior close to non-shrink firing by itself. To be able to. At this time, since the present invention calculates the shrinkage rate of the multilayer ceramic substrate and determines the filling height of the via electrode, the height of the substrate and the height of the via electrode become the same after firing, and no defect due to the protrusion of the via electrode occurs. Can be.

  An unsintered multilayer ceramic substrate according to an embodiment of the present invention includes a ceramic green sheet having at least one via hole, a polymer resin layer formed on one surface of the ceramic green sheet, and the polymer resin layer. And a ceramic laminate having a via electrode formed of a conductive metal powder inside the via hole, and a shrinkage-suppressing green sheet disposed on one or both sides of the ceramic laminate, The height is lower than the height of the via hole.

  FIG. 2 is a cross-sectional view illustrating an unsintered multilayer ceramic substrate having via holes formed during the manufacturing process of the non-shrinkable multilayer ceramic substrate according to an embodiment of the present invention.

  As shown in FIG. 2, the unsintered multilayer ceramic substrate of the present invention includes a ceramic laminate 210 formed by laminating a plurality of ceramic green sheets 201 on which via holes 203 and electrode patterns (not shown) are formed, The ceramic laminate 210 is composed of a shrinkage-suppressing green sheet 230 for non-shrinkage firing. The unsintered multilayer ceramic substrate includes a polymer resin layer 205 that supports the conductive metal powder 207 filling the via hole 203 between the ceramic green sheets 201.

  Here, the via hole 203 is filled with only the conductive metal powder 207 by an aerosol deposition method without using a binder or a solvent. At the time of non-shrinkage firing, the substrate hardly shrinks in the main surface direction and shrinks only in the thickness direction, so that the thickness of the substrate after firing is reduced by about 40 to 50% compared to before firing. Therefore, the conductive metal powder 207 is preferably filled in the via hole by about 50% to 60% with respect to the total height of the via hole before firing in consideration of the height of the via hole shrinking together with the substrate.

  Meanwhile, a method of manufacturing a non-shrinkable multilayer ceramic substrate according to another embodiment of the present invention includes a step of forming at least one via hole and an electrode pattern in at least one ceramic green sheet among a plurality of ceramic green sheets; A step of bonding a polymer resin layer to one side of the formed ceramic green sheet, and using an aerosol deposition method in a region exposed by the via hole in the polymer resin layer, the height is lower than the height of the via hole. A step of forming a via electrode, a step of laminating the ceramic green sheets to form a ceramic laminate, and a non-sintered multilayer ceramic substrate by bonding a shrinkage-suppressing green sheet to one or both sides of the ceramic laminate And sintering the green multilayer ceramic substrate. It includes a floor, a.

  3 to 6 are cross-sectional views for explaining a method of manufacturing a non-shrinkable multilayer ceramic substrate according to an embodiment of the present invention.

  As shown in FIG. 3, via holes 203 and electrode patterns (not shown) are formed in a plurality of ceramic green sheets 201. Here, the ceramic green sheet 201 is manufactured through the following manufacturing process. First, a predetermined resin, a dispersant and a mixed solvent are added to the glass-ceramic powder. The glass-ceramic powder can be dispersed by adding a predetermined amount of a dispersant. An acrylic resin can be used as the resin, and toluene and ethanol can be used as the mixed solvent.

  Such a mixed liquid is formed into a ceramic green sheet having a desired thickness by using a doctor blade method through dispersion, slurrying, filtration and defoaming processes using a ball mill. The ceramic green sheet is cut into a certain size, and the same printed circuit pattern as the desired via hole and electrode pattern is formed.

  Thereafter, the polymer resin layer 205 is bonded to the ceramic green sheet 201 in which the via hole 203 is formed. The polymer resin layer 205 is a layer that supports the conductive metal powder 207 so that the conductive metal powder 207 is injected and filled into the via hole 203.

  Such a polymer resin layer 205 is formed by coating a solution of a thermally decomposable polymer in a solvent on a carrier film. The thermally decomposable polymer is composed of vinyl resins such as polyvinyl alcohol, polyvinyl butyral and polyvinyl chloride, cellulose resins such as methylcellulose, ethylcellulose and hydroxyethylcellulose, and acrylic resins such as polyacrylic ester and polymethylmethacrylate. It can be at least one resin selected from the group. In addition, any compatible binder resin that can be used to process parts made of water-soluble binder resins or other ceramic green sheets can be used.

  Next, the conductive metal powder 207 is filled into the via hole 203 of the ceramic green sheet 201 to which the polymer resin layer 205 is bonded using an aerosol deposition method. As a result, a via electrode supported by the polymer resin layer 205 is formed. At this time, the conductive metal powder 207 filled in the via hole 203 may be one of a group including Ag, Cu, Ni, Au, AgPd, and the like. Any metal that can be applied to the ceramic package is possible.

  Here, the height of the conductive metal powder 207 filled in the via hole 203 can be freely controlled according to the design and deposition conditions, and the thickness of the ceramic substrate is 40 to 50% during non-shrinkage firing. In consideration of a decrease in the degree, about 50% to 60% is preferable with respect to the overall height of the via hole 203. The shrinkage rate of the non-shrinkable fired substrate can be accurately measured through a prior experiment, whereby the filling height of the conductive metal powder via hole can be precisely controlled.

  On the other hand, a pattern mask (not shown) may be used on the ceramic green sheet 201 so as to prevent the conductive metal powder from being sprayed to portions other than the via hole when the conductive metal powder is filled in the via hole.

  Therefore, as shown in FIG. 4, a plurality of ceramic green sheets 201 formed with via holes 203 filled with conductive metal powder 207 and electrode patterns (not shown) are laminated and then heat-pressed to form a ceramic laminate 210. Form.

Thereafter, as illustrated in FIG. 5, a shrinkage-suppressing green sheet 230 for suppressing shrinkage in the main surface direction is bonded to one surface or both surfaces of the ceramic laminate 201. The shrinkage-suppressing green sheet 230 is a soluble ceramic green sheet composed of a hardly sinterable powder that is not sintered at a normal LTCC firing temperature of 900 ° C. or less, and the shrinkage-suppressing green sheet is the ceramic laminate. It consists of a hardly sinterable powder having a sintering temperature higher than the temperature at which the material is sintered, and the hardly sinterable powder is alumina (Al ₂ O ₃ ), cerium dioxide (CeO ₂ ), zincation (ZnO ₂ ), zirconia It can be any one of (ZrO ₂ ), magnesia (MgO), and boron nitride (BN).

  In this way, the unsintered multilayer ceramic substrate on which the shrinkage-suppressing green sheet 230 is formed is sintered at a firing temperature of 870 ° C. for 1 hour, for example. At this time, the upper and lower portions of the ceramic laminate 210 are entirely restrained by the shrinkage-suppressing green sheet 230, and the via hole 203 in the ceramic laminate 210 is a via that has almost no shrinkage due to the densely formed conductive metal powder 207. An electrode is formed.

  Then, in the firing process, the polymer resin layer 205 in the ceramic laminate 210 is completely decomposed and vaporized at a calcination temperature of 400 to 500 ° C., and only the ceramic green sheet 201 remains and is densified.

  In addition, while the ceramic laminate 210 shrinks in the thickness direction, the conductive metal powder 207 filled in the via hole 203 is formed in a state of being already densely packed before firing by an aerosol deposition method. There is almost no shrinkage of volume during firing. Accordingly, the ceramic laminate 210 contracts to the height of the conductive metal powder 207 filled in the via hole 203.

  Therefore, as shown in FIG. 6, at the interface between the sintered ceramic body 270 and the via hole 250 after firing, there is almost no contraction of the via electrode, so that not only pores are not generated in the via hole 250 but also the via electrode does not protrude. The substrate 200 is completed.

  As described below, the conductive metal powder is sprayed using the aerosol deposition method corresponding to the conditions of the present invention to fill the inside of the via hole, and the shrinkage-suppressing green sheets are bonded to both surfaces of the ceramic laminate, and then fired. The process was carried out to produce a non-shrinkable multilayer ceramic substrate.

[Manufacture of ceramic laminates]
First, in order to manufacture a low dielectric constant ceramic green sheet constituting a multilayer ceramic substrate, 15 wt% of an acrylic binder and 0.5 wt% of a dispersant are added to 100% of glass-ceramic powder, and toluene and ethanol are mixed. After adding the solvent, it was dispersed using a ball mill.

  The slurry thus obtained was filtered through a filter and defoamed, and a ceramic green sheet having a thickness of 100 μm was formed using a doctor blade method. Thereafter, the ceramic green sheet was cut into a certain size and punched to form a via hole having a diameter of 120 μm.

  In order to fill the formed via hole with the conductive metal powder, a polymer resin layer was bonded to one surface of the ceramic green sheet. Thereafter, the conductive metal powder was filled into the via hole only to a certain height of the via hole in consideration of the shrinkage ratio of the ceramic green sheet by using an aerosol deposition method. Thereafter, a plurality of ceramic green sheets on which via holes and electrode patterns were formed were laminated and then heat-pressed to produce an integrated ceramic laminate.

[Bonding of ceramic laminate and green sheet for shrinkage suppression]
A green sheet for shrinkage suppression having a thickness of 200 μm cut to the same area as the ceramic laminate was bonded to both surfaces of the ceramic laminate. Then, the unsintered multilayer ceramic substrate integrated by thermocompression bonding was manufactured. This shrinkage-suppressing green sheet is bonded to both surfaces of the ceramic laminate, and suppresses the ceramic laminate from shrinking in the main surface direction during the firing process.

[Sintering]
An unsintered multilayer ceramic substrate having the shrinkage-suppressing green sheets bonded to both surfaces of the ceramic laminate was sintered at a firing temperature of 870 ° C. for 1 hour. The green sheet for shrinkage suppression was removed from the sintered body thus obtained. That is, after sintering the unsintered multilayer ceramic substrate, the green sheets for suppressing shrinkage on both sides of the sintered body remain unsintered. Therefore, it was removed from the surface of the sintered body by washing with water, ultrasonic cleaning, sand blasting, high pressure spraying or the like.

  As a result, as intended in the present invention, the upper and lower portions of the ceramic laminate are entirely constrained by the shrinkage-suppressing green sheets, and via electrodes filled only with conductive metal powder without a binder or solvent by an aerosol deposition method. Is a densified normal state that has almost no pores before firing, so that it hardly shrinks in the firing process and forms a via electrode that is completely filled in the via hole. Considering the shrinkage rate of the green sheet, it was filled only to a certain height, so that a multilayer ceramic substrate in which no pores were generated in the via hole after firing and the via electrode did not protrude was completed.

  The present invention is not limited by the above embodiments and the accompanying drawings, but is limited by the appended claims. Accordingly, various forms of substitutions, modifications and changes can be made by those having ordinary knowledge in the art without departing from the technical idea of the present invention described in the claims. Belongs to a range.

Claims (19)

A ceramic green sheet having at least one via hole formed thereon, a polymer resin layer formed on one surface of the ceramic green sheet, and a conductive metal powder supported by the polymer resin layer and formed in the via hole. A ceramic laminate having a via electrode, and a green sheet for shrinkage suppression disposed on one or both surfaces of the ceramic laminate,
The unsintered multilayer ceramic substrate, wherein a height of the via electrode is lower than a height of the via hole.   2. The unsintered multilayer ceramic substrate according to claim 1, wherein a height of the via electrode is 50% to 60% with respect to a height of the via hole in consideration of a contraction degree of the ceramic laminate.   The unsintered multilayer ceramic substrate according to claim 1 or 2, wherein the conductive metal powder is one of Ag, Cu, Ni, Au, and AgPd.   The unsintered body according to any one of claims 1 to 3, wherein the polymer resin layer is composed of a thermally decomposable polymer that is decomposed and removed at a temperature equal to or lower than a temperature at which the ceramic laminate is sintered. Multilayer ceramic substrate.   The thermally decomposable polymer is composed of a vinyl resin including polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, a cellulose resin including methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose, and an acrylic resin including polyacryl ester and polymethyl methacrylate. The green multilayer ceramic substrate according to claim 4, wherein the green multilayer ceramic substrate is at least one selected from the group described above.   The unsintered powder according to any one of claims 1 to 5, wherein the shrinkage-suppressing green sheet is composed of a non-sinterable powder having a sintering temperature higher than a temperature at which the ceramic laminate is sintered. Multi-layer ceramic substrate. The hardly sinterable powder is any one of alumina (Al ₂ O ₃ ), cerium dioxide (CeO ₂ ), zincation (ZnO ₂ ), zirconia (ZrO ₂ ), magnesia (MgO), and boron nitride (BN). The unsintered multilayer ceramic substrate according to claim 6, wherein Forming at least one via hole and electrode pattern in at least one ceramic green sheet of the plurality of ceramic green sheets;
Bonding a polymer resin layer to one surface of the ceramic green sheet in which the via hole is formed;
Forming a via electrode at a height lower than the height of the via hole using an aerosol deposition method in a region exposed by the via hole in the polymer resin layer;
Laminating the ceramic green sheets to form a ceramic laminate;
Bonding a green sheet for shrinkage suppression to one or both sides of the ceramic laminate to form an unsintered multilayer ceramic substrate;
Sintering the unsintered multilayer ceramic substrate.   The multilayer ceramic substrate according to claim 8, wherein forming the via electrode is a step of forming a dense via electrode made of only the conductive metal powder through high-speed injection of the conductive metal powder by the aerosol deposition method. Manufacturing method.   In the step of forming the via electrode, before spraying the conductive metal powder, a pattern mask is disposed on the ceramic green sheet so that only a region exposed by the via hole in the polymer resin layer is opened. The method of manufacturing a multilayer ceramic substrate according to claim 9, further comprising a step.   The method for producing a multilayer ceramic substrate according to claim 9 or 10, wherein the conductive metal powder is any one of Ag, Cu, Ni, Au, and AgPd.   The method for manufacturing a multilayer ceramic substrate according to claim 8, wherein the height of the via electrode is determined by a shrinkage rate of the ceramic green sheet.   The method of manufacturing a multilayer ceramic substrate according to claim 12, wherein the height of the via electrode is a height corresponding to a sintered ceramic green sheet in consideration of a shrinkage rate of the ceramic green sheet.   The multilayer ceramic substrate according to any one of claims 8 to 13, wherein the polymer resin layer is composed of a thermally decomposable polymer that is decomposed and removed at a temperature lower than a temperature at which the ceramic green sheet is sintered. Manufacturing method.   The thermally decomposable polymer is composed of a vinyl resin including polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, a cellulose resin including methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose, and an acrylic resin including polyacryl ester and polymethyl methacrylate. The method for producing a multilayer ceramic substrate according to claim 14, wherein the multilayer ceramic substrate is at least one selected from the group described above.   The method for producing a multilayer ceramic substrate according to any one of claims 8 to 15, further comprising a step of removing the shrinkage-suppressing green sheet from the sintered multilayer ceramic substrate.   The method of manufacturing a multilayer ceramic substrate according to claim 16, wherein the step of removing the shrinkage-suppressing green sheet from the sintered multilayer ceramic substrate is performed by any one of lapping, sandblasting, washing with water and high-pressure spraying. .   The multilayer ceramic according to any one of claims 8 to 17, wherein the shrinkage-suppressing green sheet is composed of a hardly sinterable powder having a sintering temperature higher than a temperature at which the ceramic laminate is sintered. A method for manufacturing a substrate. The hardly sinterable powder is any one of alumina (Al ₂ O ₃ ), cerium dioxide (CeO ₂ ), zincation (ZnO ₂ ), zirconia (ZrO ₂ ), magnesia (MgO), and boron nitride (BN). The method for producing a multilayer ceramic substrate according to claim 18, wherein

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