JPH07321466A - Production of multilayer ceramic board - Google Patents

Abstract

PURPOSE:To produce a multilayer ceramic board efficiently while enhancing the overall mechanical strength and the dimensional accuracy. CONSTITUTION:A ceramic powder, a binder, a solvent, a plasticizer, and the like, are mixed to produce a slurry for forming green sheets 1, 1a. A pattern of a conductor paste is then printed on the surface each of the green sheets 1, 1a. Normally, the temporary press process following the pattern printing process is not eliminated but the drying operation for decreasing the plasticizer in time green sheets 1, 1a lower than 10wt.% of the initial compounding quantity is continued just before a lamination process. Subsequently, lamination, temporary firing, and main firing processes are carried out thus producing a multilayer ceramic board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer ceramic substrate.

[0002]

2. Description of the Related Art As a multilayer substrate for mounting ICs, LSI chips and the like, various types have been proposed so far. Especially in recent years, for the purpose of protecting highly integrated and highly functional electronic components from thermal damage,
A multilayer ceramic substrate using a ceramic material having good thermal conductivity has been manufactured.

A multilayer ceramic substrate is produced by using a slurry obtained by adding and kneading a binder, a sintering aid, a plasticizer, etc. to ceramic powder as a starting material. The slurry is formed into a sheet by a doctor blade method or the like. The green sheet obtained by the molding process,
Through-hole forming holes, positioning holes, and the like are provided as needed. On the green sheet that has undergone the perforation process,
The conductor paste is printed. A plurality of green sheets that have undergone the pattern printing process are stacked on a pressing jig and thermocompression bonded by a laminating process. The laminated body obtained by the laminating step becomes a sintered body through the steps of degreasing, calcination and main calcination.

By the way, in the case of the green sheet obtained by the conventional method, since the laminating step is carried out in a state in which a large amount of the plasticizer is contained, volatile gas is easily generated and swelling between layers (so-called delamination) is likely to occur. . And this has been a cause of deterioration of dimensional accuracy and lot out. Further, as the delamination progresses, the adhesion strength between layers deteriorates, and as a result, the mechanical strength of the entire substrate may decrease.

Therefore, conventionally, the step of pressing the green sheet on which the conductor pattern is formed with a predetermined pressing force (so-called temporary pressing step) has been carried out between the pattern printing step and the laminating step. That is, the conductor pattern is embedded in the green sheet by the temporary pressing process,
By flattening the pattern printing surface, the adhesion strength between the sheets is ensured.

[0006]

However, in the case of the prior art, when the pressure and time for temporary pressing are insufficient, volatile gas is likely to accumulate around the conductor pattern, so that delamination or the like is reliably prevented. Can not do. Therefore, in the past, a considerable pressing pressure (80
It was necessary to carry out temporary pressing for a predetermined time at (kgf / cm ² or more). As a result, the operating efficiency of the equipment is deteriorated, and as a result, the amount of substrates that can be manufactured in one day is reduced. Moreover, it has been known that the above-mentioned insufficient temporary press pressure becomes a serious problem when manufacturing a narrow pitch product, a product having a large number of products, a product having a high pattern printing rate, and the like.

Further, when a large press pressure is set, residual stress and dimensional variation are generated, which makes it difficult to obtain a substrate having excellent dimensional accuracy.

The present invention is intended to solve the above problems, and an object of the present invention is to improve the mechanical strength and dimensional accuracy of the entire substrate and to manufacture a multilayer ceramic efficiently. It is to provide a method for manufacturing a substrate.

[0009]

In order to solve the above problems, according to the invention of claim 1, a ceramic powder,
Forming step of forming a green sheet from a slurry formed by mixing a binder, solvent, plasticizer, etc., pattern printing step of printing a conductor paste on the surface of the green sheet, temporary pressing step of flattening the surface on which the conductor pattern is printed A laminating process in which green sheets are laminated and thermocompression-bonded,
In a method for manufacturing a multilayer ceramic substrate including a calcination step and a main calcination step for a laminate, instead of omitting the tentative pressing step, a plasticizer in the green sheet is dried to 10% by weight or less of an initially blended amount. The gist is a method of manufacturing a multilayer ceramic substrate, which is performed before the laminating step.

According to a second aspect of the present invention, in the manufacturing method according to the first aspect, pressure is applied with a cushioning material arranged between the pair of pressing jigs used in the laminating step and the green sheet. It is carried out. According to the invention of claim 3, in the manufacturing method of claim 1 or 2, the cushioning material is a resin plate having elasticity.

[0011]

According to the method of the present invention described in claims 1 to 3, the plasticizer, which is a source of residual gas, is sufficiently removed from the green sheet before the laminating step. For this reason,
Even if the temporary pressing step is not particularly performed, delamination of the green sheet due to escape of residual gas can be prevented.

In particular, according to the method of the present invention as defined in claim 2, since the cushioning material interposed between the pressing jig and the pressing member evenly applies pressure to the green sheet, delamination of the green sheet can be prevented more reliably. can do.

According to the method of the third aspect of the present invention, it is possible to more surely realize the uniform pressurization as compared with the case where, for example, a paperboard having no elasticity is used as the cushioning material. Moreover, since the resin plate has elasticity, it is unlikely to be deformed and can be repeatedly used.

The method of manufacturing the multilayer ceramic substrate of the present invention will be described in detail below in the order of steps. Examples of ceramic materials for forming the green sheet include aluminum nitride (AlN), alumina (Al ₂ O ₃ ), mullite (3Al ₂ O ₃ .2SiO ₂ ), and silicon carbide (Si).
Powders such as C) are used. Among them, AlN which can obtain a substrate excellent in electrical insulation and thermal conductivity among others.
It is desirable to select the powder of Next, a predetermined amount of binder, sintering aid, plasticizer, solvent, and the like are added to the ceramic powder selected from those listed above.

Among the above substances, the plasticizer and the solvent are volatile components, and the ceramic powder, the sintering aid and the binder are solid contents. Usually, the content of the volatile component is about 20 to 30% by weight of the solid content. The main component of the volatile component is the solvent. The content of the plasticizer is a fraction to one tenth of the content of the solvent. The boiling point of the plasticizer used is generally higher than that of the solvent in many cases.

By uniformly kneading the mixture,
A raw material slurry for producing a green sheet is obtained. Then, a green sheet is continuously formed from the raw material slurry by, for example, a doctor blade method. Here, drying is performed to such an extent that the raw material slurry loses fluidity and can retain the sheet shape, that is, about 80% of the volatile components (mainly solvent) in the green sheet are removed.

Hereinafter, the drying performed at this stage is referred to as "primary drying" for convenience of explanation. In addition, hereinafter, the term "green sheet" refers to a sheet-shaped ceramic molded body that has undergone primary drying. At this time, while the solvent is removed by the primary drying, the plasticizer is hardly removed. Therefore, the green sheet after the primary drying still has plasticity.

The green sheet that has undergone the primary drying is dried again after the contour cutting. Drying at this stage removes solvent but little plasticizer. Hereinafter, the drying performed at this stage is referred to as "secondary drying" for convenience of description. About 8 green sheets in the secondary drying process
It is dried at 0 ° C. for several hours.

The green sheet which has been subjected to the secondary drying is provided with through-hole forming holes and positioning holes through punching or the like. Further, a conductor paste containing a refractory metal as a main component is printed on the green sheet that has been subjected to the above-mentioned perforation step. Through the through-hole printing process, the through-hole forming holes are filled with the conductor paste, and as a result, the through-hole conductor circuit is formed. As the high melting point metal in the conductor paste, for example, tungsten (W), molybdenum (Mo), tantalum (Ta), niobium (Nb) or the like is used. Among these metals, it is desirable to select W powder having excellent cost performance, etc., in order to reduce the cost of the entire substrate.

After that, drying is performed for the purpose of removing the solvent in the printed paste. Hereinafter, the drying performed at this stage is referred to as “tertiary drying” for convenience of description.
However, the plasticizer in the green sheet is hardly removed even after the third drying. In this third drying process,
The green sheet is dried at around 70 ° C. for about 10 to 30 hours.

The above-described conductor paste is printed again on the surface of the green sheet which has been subjected to the third drying. Through such a pattern printing process, a conductor pattern is formed on the surface of the green sheet.

A plurality of green sheets having the conductor pattern formed thereon are placed on a pressing jig for lamination in a state of being stacked. It should be noted that another green sheet that does not contain a sintering aid is arranged in the outermost layer of the green sheet. Before or after stacking the green sheets, the green sheets are dried. Less than,
The drying performed at this stage is called "quaternary drying" for convenience of description. In the fourth drying process, the green sheet is 80 ° C-1
It is dried at 20 ° C. for 20 to 80 hours. The plasticizer remaining in the green sheet needs to be removed to 10% by weight or less of the initial blending amount by undergoing the fourth drying step. This is because unless the plasticizer is removed to the above degree, the amount of volatile gas generated cannot be reduced in the subsequent laminating step.

Each green sheet that has undergone the quaternary drying is directly subjected to the laminating step without passing through the usual temporary pressing step. The green sheets are thermocompression-bonded to each other in the laminating process to form a laminate.

The laminating step mainly consists of vacuuming the inside of the laminating apparatus and pressing the green sheet.
When applying pressure to the green sheet, it is desirable to dispose a cushioning material between the pair of pressing jigs and the green sheet. In this case, a plate material having a certain thickness and made of a material that is at least softer than a jig made of metal or a green sheet made of ceramics (for example, a resin plate or paperboard) is used as the cushioning material.

The substance used as the cushioning material is at least the temperature at the time of lamination (about 100 ° C.
It is preferably capable of withstanding 150 ° C.) and pressure (70 kg / cm ^{2 to} 90 kg / cm ² ) for a predetermined time.

Examples of the resin plate include natural rubber, silicone rubber, urethane rubber, polysulfide rubber, fluororubber,
There are sheets of resin having elasticity such as synthetic rubber such as diene rubber, olefin rubber, and vinyl rubber.
Examples of paperboard include corrugated cardboard, white paperboard, yellow paperboard,
There are papers that are somewhat thicker than Western paper, such as colored balls and construction paper. In this case, it is preferable to select a resin plate having elasticity rather than a paperboard having no elasticity, and it is also preferable to select a silicone rubber having excellent heat resistance among the resin plates.

The thickness of the cushioning material is preferably 0.1 mm to 10 mm, and particularly preferably 0.5 mm to 3 mm. If the cushioning material is too thin, pressure equalization may not be sufficiently achieved. On the other hand, if the cushioning material is too thick, heat may be difficult to transfer from the pressing jig side. A release paper having a thickness of about several tens of μm, which is commonly used, does not satisfy the condition of the thickness, and therefore is not included in the concept of the cushioning material here.

After that, the laminated body obtained by the laminating step is further subjected to degreasing, calcination and main calcination under predetermined conditions to become a sintered body.

[0029]

EXAMPLE An example in which the present invention is embodied in a method for manufacturing a multilayer aluminum nitride substrate (multilayer AlN substrate) will be described in detail with reference to FIGS. Here, three methods (two of which correspond to the embodiment) are used.
Various kinds of samples were prepared and evaluated.

First, to 1000 g of AlN powder having an average particle diameter of 1.7 μm, 11 g of acrylic binder, 4.0 g of Y ₂ O ₃ as a sintering aid, and 30 g of butanol and ethanol as a solvent in total, and D as a plasticizer
OA [Dioctyl adipate, boiling point = 335 ° C (760 mmH
g)] was added. Then, by kneading this mixture uniformly with a ball mill, the green sheet 1
A uniform raw material slurry for preparation was prepared. Further, a raw material slurry was prepared by removing only Y ₂ O ₃ from the raw material slurry and used as the raw material slurry for producing the outermost green sheet 1a.

Next, a 0.4 mm thick green sheet 1 and the outermost green sheet 1a were continuously formed from the two kinds of raw material slurry by the doctor blade method. About 80% of the solvent in the green sheets 1 and 1a was removed by the primary drying performed in the drying furnace of the sheet forming machine.

Further, the obtained green sheets 1, 1a
After cutting the outer shape to 200mm square, green sheet 1,
Secondary drying was performed on 1a at 80 ° C. for 5 hours. By this secondary drying, the solvent in the green sheets 1 and 1a was almost completely removed, and the plasticizer DOA was reduced to about 90% by weight of the initial blending amount.

Then, after sticking an adhesive film (not shown), the through-hole forming hole 2 and the positioning hole 2a were formed by punching predetermined coordinates on the green sheet 1 by punching. By the same procedure,
Positioning holes 2a were also formed in the outermost green sheet 1a.

Next, the green sheet 1 which has undergone the perforating step
Was set in a screen printing machine, and the W paste 10 was screen printed on the green sheet 1. Through the through-hole printing process, the through-hole conductor circuit 3a was formed inside the through-hole forming hole 2 as shown in FIG. Here, 2,000 g of W powder having an average particle diameter of 3.4 μm was mixed with 1.9% by weight of an acrylic binder, 2.7% by weight of α-terpineol as a solvent and 0.1% by weight of a dispersant. Then, the W paste 10 was used after being uniformly mixed.

Next, the green sheet 1 was transferred into a dryer and subjected to tertiary drying at 70 ° C. for 3 hours to mainly remove the solvent in the W paste 10. Next, the green sheet 1 that had been subjected to the third drying was set again in the screen printing machine, and screen printing was performed using the W paste 10 described above.
As a result, as shown in FIG. 1, the conductor pattern 3b was formed on the surface of the green sheet 1. Further, as shown in FIG. 2, the solid pattern 3c for preventing W carbonization was formed on the entire one surface of the outermost green sheet 1a by screen printing using the same W paste 10. The processes up to this point are not particularly different from the three methods of producing samples.

As for the samples, the green sheets 1 and 1 are then attached to the upper surface of the pressing jig 4 having the guide pins 4a.
a was fixed, and the fourth drying (100 ° C., 30 hours to 40 hours) was performed on the green sheets 1 and 1a.
Then, after peeling off the adhesive film from the green sheets 1 and 1a for which the fourth drying was completed, a laminating step was performed under predetermined conditions.

However, regarding the lamination of the sample, as shown in FIG. 3, a silicone rubber 6 having a thickness of 2 mm and a release paper 5 having a thickness of 50 μm as a cushioning material are used as a pair of pressing jig 4 and green sheet 1a. Intervened between.
On the other hand, in the laminating of the sample, as shown in FIG. 5, only the release paper 5 having a thickness of 50 μm was interposed between the pressing jig 4 and the green sheet 1a as in the conventional case.

The green sheets 1 and 1a of the sample (that is, the comparative example) were immediately subjected to the laminating step without performing the fourth drying. Table 1 shows the residual amount (% by weight) of the plasticizer of each sample immediately before the laminating step.
It is shown. In the sample subjected to the fourth drying, the residual amount of the plasticizer was 10% by weight. On the other hand, in the sample which was not subjected to the fourth drying, the residual amount of the plasticizer was 9%.
It was 0% by weight. In the laminating process,
As with the sample, the surface pressure when applying pressure is 80 kg / cm
² was uniformly set the temperature of the pressurization to 130 ° C..

After carrying out the laminating step and the like under each of the conditions, the laminate 7 was degreased in an inert atmosphere and then calcined. Then, the occurrence rate (%) of delamination in the obtained calcined body was investigated by touch and sight. As shown in Table 1, the sample had no delamination, whereas the sample had an extremely high incidence of 72%.

[0040]

[Table 1]

Next, the calcined body was set in a hot press machine and subjected to main firing under predetermined conditions. Further, after the outer shape of the obtained sintered body 8 was cut, surface grinding and the like were performed.
As a result, as shown in FIG. 4, the final product, a multilayer AlN substrate 9, was obtained.

Samples Obtained as Above
Was used to perform a tensile test by a conventionally known method. Here, the adhesion strength between AlN and AlN (kgf / c
m ² ) and the adhesion strength between AlN and W (kgf / cm ² ) were measured. The results are shown in Table 2.

[0043]

[Table 2]

As a result, in both the adhesion strength between AlN and AlN and the adhesion strength between AlN and W, the sample was superior to the sample of the comparative example. In addition, comparing the samples, it was found that the sample using the silicone rubber 6 gives better results.

Further, in the sample, the fracture often occurred at the interface of the sheet, whereas in the sample, the fracture often occurred inside the sheet. Summarizing the above results, the following can be said. That is, according to the method of the embodiment, the plasticizer, which is a source of residual gas, can be sufficiently removed from the green sheets 1 and 1a before the laminating step. For this reason, it is possible to prevent delamination of the green sheets 1 and 1a due to the escape of the residual gas without performing the temporary pressing process. Therefore, the finally obtained multilayer AlN substrate 9 also has excellent mechanical strength. Further, according to this method, the temporary pressing step can be omitted,
The operating efficiency of the equipment will be better than before, and the number of layers A
The amount by which the 1N substrate 9 can be manufactured also increases. That is, multi-layer A
It becomes possible to efficiently manufacture the 1N substrate 9. Furthermore, since the problem of residual stress in the green sheets 1 and 1a is solved accompanying the non-execution of the temporary pressing step, the dimensional accuracy of the multilayer AlN substrate 9 is also improved. Of course, the elimination of the temporary pressing step is extremely advantageous in manufacturing narrow-pitch products, products with a large number of products, products with a high pattern printing rate, and the like.

Further, in the case of the sample manufacturing method, since the silicone rubber 6 is interposed between the pressing jig 4 and the green sheets 1 and 1a, the pressure is evenly applied to the green sheets 1 and 1a in the laminating step. be able to. Therefore, the green sheet 1, which is caused by the uneven pressure,
The delamination of 1a can be prevented more reliably. Further, since the silicone rubber 6 is adopted, it is possible to more surely realize the uniform pressurization as compared with the case where, for example, a paperboard having no elasticity is used as the cushioning material. Moreover, since the silicone rubber 6 is unlikely to be deformed, it has an advantage that it can be repeatedly used.

Next, a test conducted on the dimensional change of the conductor pattern 3b in addition to the above-mentioned test on the adhesion strength will be described with reference to FIGS. 6 (a) to 6
(C) conceptually shows how the dimensions change when the conductor pattern 3b is formed according to the conventional method. In FIG. 6A, the W paste 1 is formed on the surface of the green sheet 1.
The pattern printed 0 is shown. At this point, the printed W paste 10 has an elliptical cross-sectional shape. When the temporary pressing is performed by the pressing jig 11 for the temporary pressing, the W paste 10 is embedded in the green sheet 1 as shown in FIG. 6B. As a result, the pattern printing surface becomes flat. Then, when a laminating step is performed, a laminate 7 having a conductor pattern 3b having a cross-sectional shape as shown in FIG. 6C is obtained. That is, according to the conventional method, the conductor pattern 3b having a vertically asymmetrical shape with respect to the sheet interface is formed. This is because the pressing jig 11 is generally harder than the green sheet 1.

On the other hand, FIGS. 7A and 7A conceptually show how the dimensions change when the conductor pattern 3b is formed according to the method of the embodiment. Similar to FIG. 6A, FIG. 7A shows a state in which the W paste 10 is pattern-printed on the surface of the green sheet 1. When the laminating process is performed without performing the temporary pressing, the result shown in FIG.
A laminated body 7 having a conductor pattern 3b having a cross-sectional shape as shown in (b) is obtained. That is, according to the method of the embodiment, the conductor pattern 3b having a substantially saw-tooth cross section, which is substantially vertically symmetrical with respect to the sheet interface, is formed. It is speculated that this is because the lamination pressure is applied in the state where the green sheets 1 are present above and below the printed W paste 10. The conductor pattern 3b
The data showing the dimensional change of is shown in Table 3. In the table,
The data in the column "Before temporary press" is shown in Fig. 6 (a) and Fig. 7 (a).
Corresponds to the data of width w and thickness h. The data in the column “after provisional pressing” corresponds to the data of width w and thickness h in FIGS. 6B and 6C. "No temporary press"
The data in the column corresponds to the data of the width w and the thickness h in the case of FIG. 7B.

[0049]

[Table 3]

The present invention is not limited to the above embodiment, but can be modified as follows.
For example, (a) the ceramic powder may be other than AlN powder. The number of stacked green sheets 1 and 1a is also arbitrary.

(B) The release paper 5 arranged between the green sheet 1a and the silicone rubber 6 is not particularly essential. Instead of the above method, the surface of the silicone rubber 6 may be coated with a release agent or the like.

(C) When performing the fourth drying, the green sheets 1 and 1a do not necessarily have to be dried on the pressing jig 4. However, when it is desired to reduce the residual amount of the plasticizer to 10% by weight or less in the quaternary drying, there is an advantage that the handling property is not impaired if the drying is performed on the pressing jig 4. Further, it can be said that it is also preferable from the viewpoint of improving the handling property to perform drying with the adhesive film attached as in the example. Of course, this adhesive film can be omitted.

(D) Predetermined conditions (eg hardness, thickness,
Not only resin boards and paperboards, but also soft metal board materials, natural products typified by cotton and leather, and ceramic fiber papers can be used as cushioning materials as long as they satisfy conditions such as heat resistance. Is.

(E) When drying the green sheets 1 and 1a, the temperature and time of the third drying and the fourth drying can be arbitrarily changed. For example, a combination of 70 ° C, 2 hours of tertiary drying and 100 ° C, 40 hours of fourth drying, RT (room temperature), 20 hours of tertiary drying and 100 ° C, 5
It may be a combination with 0-hour quaternary drying or the like. Even in cases such as these, the plasticizer content of 10% by weight of the initial blending amount
It can be: However, if the time and temperature are set as in the embodiment, the total time required for the third drying and the fourth drying is the shortest.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments and other examples will be listed below together with their effects. (1) In claim 3, the cushioning material is a silicone rubber having a thickness of 2 mm to 3 mm. According to this method, it is possible to sufficiently achieve equalization of pressure, it is difficult for heat to be transferred from the jig side, and there is no fear that the cushioning material is deteriorated by heat during lamination.

(2) In a multilayer AlN substrate formed by laminating, degreasing, pre-baking and main-baking an AlN green sheet on the surface of which a W paste is printed in a pattern, a shape that is almost vertically symmetrical with respect to the sheet interface Multi-layer AlN with inner layer conductor pattern having a cross-section with a substantially saw-tooth shape
substrate. With this structure, a substrate having excellent electric characteristics can be obtained (?).

(3) In claims 1 to 3, after the through-hole printing step, the green sheet is subjected to tertiary drying at about 70 ° C. for 10 to 20 hours, then the pattern printing step is performed, and then 80 to the green sheet. Quaternary drying at 20 to 80 ° C for 20 to 80 hours. With this method, the plasticizer in the green sheet can be removed up to a predetermined amount in a relatively short time.

(4) In claims 1 to 3, the adhesive film is attached to at least one surface of the green sheet during the process from the perforating step to the laminating step. According to this method, the handleability of the green sheet can be improved.

For the technical purposes used in this specification
The word is defined as follows. "Ceramics substrate: Aluminum nitride (Al
N), boron nitride (BN), silicon carbide (SiC), etc.
Other than substrates made of non-oxide ceramics
For example, alumina (Al₂O₃), Beryllia (BeO), Mu
Light (3Al₂O ₃・ 2SiO₂), Glass ceramic
Cus (MgO-Al₂O₃-SiO₂And BaO-Al₂
O₃-SiO₂Etc.), forsterite (2MgO.S)
iO₂), Spinel (MgO ・ Al₂O₃) Etc.
It also means a substrate made of oxide-based ceramics, etc.
It "

[0060]

As described above in detail, according to the method for manufacturing a nitride ceramics substrate of claims 1 to 3, since delamination can be prevented without performing a temporary pressing step, the entire substrate can be prevented. The mechanical strength and dimensional accuracy can be improved, and the substrate can be efficiently manufactured. Further, according to the inventions of claims 2 and 3, since delamination can be prevented more reliably,
The mechanical strength of the entire substrate can be further improved.

[Brief description of drawings]

FIG. 1 is a partial schematic cross-sectional view showing a state in which a conductor pattern is printed on the surface of a green sheet.

FIG. 2 is a partial schematic cross-sectional view showing a state in which a solid pattern is printed on the surface of the outermost green sheet.

FIG. 3 is a cross-sectional view showing a state in which silicone rubber is arranged and pressure is applied to the green sheet in the laminating step.

FIG. 4 is a sectional view showing a multilayer AlN substrate.

FIG. 5 is a cross-sectional view showing a state in which pressure is applied to the green sheet without arranging silicone rubber in the laminating step.

6A to 6C are enlarged cross-sectional views conceptually showing the dimensional change of the conductor pattern in the conventional method.

7A and 7B are enlarged cross-sectional views conceptually showing the dimensional change of the conductor pattern in the method of the embodiment.

[Explanation of symbols]

1, 1a ... Green sheet, 3b ... Conductor pattern, 4 ...
A pressing jig, 6 ... Silicone rubber as a cushioning material, 7 ... Laminated body, 9 ... A multilayer aluminum nitride substrate as a multilayer ceramic substrate, 10 ... A tungsten paste as a conductor paste.

Claims (3)

[Claims] 1. A molding process for molding a green sheet from a slurry prepared by mixing ceramic powder, a binder, a solvent, a plasticizer, etc., a pattern printing process for printing a conductor paste on the surface of the green sheet, and a conductor pattern printed. In a method for manufacturing a multilayer ceramic substrate including a temporary pressing step for flattening a surface, a laminating step for laminating and thermocompressing green sheets, a temporary baking step for a laminate and a main baking step, instead of omitting the temporary pressing step. A method for manufacturing a multilayer ceramic substrate, wherein the plasticizer in the green sheet is dried to 10% by weight or less of the initial blending amount before the laminating step. 2. The method for producing a multilayer ceramic substrate according to claim 1, wherein pressure is applied in a state where a cushioning material is arranged between the pair of pressing jigs used in the laminating step and the green sheet. 3. The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein the cushioning material is a resin plate having elasticity.