JPH0746540B2 - Method for manufacturing glass-ceramic substrate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a hybrid I
The present invention relates to a method for manufacturing a glass ceramic substrate used for C, a multi-chip module, or the like.

[0002]

2. Description of the Related Art Heretofore, a ceramic multilayer substrate has been manufactured by using alumina as an insulating layer, using tungsten or molybdenum as a conductor, and simultaneously firing the insulating layer and the conductor at a temperature of about 1600.degree. In recent years, a glass ceramic substrate has been developed as a ceramic multilayer substrate for low temperature firing. This substrate is made of glass as an insulating layer.
A paste such as gold, silver, or copper that is used as a conductor in a normal thick-film method after forming a green sheet with a doctor blade by adding a binder and a solvent to alumina-based or crystallized glass-based powder, etc. It is obtained by stacking the layers prepared by printing and firing at 800 to 1100 ° C.

[0003]

However, when the above laminate is fired, it shrinks by 10 to 20%. This shrinkage rate changes depending on the composition of the raw material, the particle size, the firing temperature, the firing time, the density of the molded body, etc., and each variation appears as a final variation in the shrinkage rate, making it difficult to control the dimensions. Since the product does not satisfy the prescribed standard dimensional accuracy, there is a problem that the yield decreases. The present invention has been proposed in view of the above problems, and it is an object of the present invention to provide a method for manufacturing a glass-ceramic substrate capable of obtaining a product with high dimensional accuracy by reducing the shrinkage ratio during firing as much as possible. To aim.

[0004]

In order to achieve the above-mentioned object, the method for producing a glass lamic substrate according to the present invention is
A glass ceramic layer is constrained by a refractory powder layer that does not substantially sinter at a temperature of 100 ° C. or less to reduce the firing shrinkage in the surface direction of the substrate as much as possible to improve the dimensional accuracy of the product. It is the one. That is, the method for producing a glass lamic substrate according to the present invention includes at least a step of forming a green sheet using glass ceramic powder as a raw material, a step of forming a green sheet using refractory powder as a raw material, and the above glass ceramic powder. A step of sandwiching both sides of one or more green sheets made of the above-mentioned green sheets with the green sheets made of the refractory powder as a raw material, press-molding, and firing the formed body at a temperature of 1100 ° C. or lower; And a step of removing refractory powder from the fired body.

[0005]

In the present invention, the glass ceramic powder is 11
Any glass powder that can be sufficiently fired at 00 ° C or lower may be used, and examples of the glass powder include borosilicate glass as a base, which contains lead oxide, zinc oxide, an oxide of an alkaline earth metal, and the like and has a softening point of 600 to 800 ° C. Crystalline glass powder, or 60
Crystallized glass that crystallizes at 0 to 1100 ° C. can be used, and a ceramic filler such as alumina, zircon, mullite, cordierite, anorthite, or silica may be mixed therein. The mixing ratio of the glass powder and the ceramic filler is adjusted in consideration of the bending strength, dielectric constant, denseness, etc. of the glass ceramic substrate, but it is generally used at a weight ratio of about 1: 1. Many.

On the other hand, the refractory powder is selected on the condition that it does not substantially sinter at a temperature of 1100 ° C. or lower and that no harmful chemical reaction with the glass ceramic powder occurs.
The reason is that when the refractory powder is sintered or chemically reacts with the glass ceramic powder in the firing step, the refractory layer cannot be easily removed from the glass ceramic layer. As the above refractory powder, for example, alumina, zirconium oxide, aluminum nitride, boron nitride, mullite, magnesium oxide, silicon carbide, etc. can be used. The larger the particle size of the refractory powder is, the easier it is to remove after firing. However, if the particle size is too large, the surface of the glass ceramic substrate becomes rough.

Samples of the above-mentioned glass-ceramic powder and refractory powder are mixed with a binder, a plasticizer, and a solvent to form a slurry, and each of them is formed into a green sheet by a doctor blade method or the like. For example, polyvinyl butyral, methacrylic polymer, acrylic polymer and the like can be used. Further, as the plasticizer, for example, a derivative of phthalic acid can be used, and as the solvent, for example, alcohols, ketones, chlorine-based organic solvents and the like can be used.

The thickness of the green sheet of glass-ceramic powder is appropriately adjusted in consideration of the bending strength of the glass-ceramic substrate to be produced, and is, for example, 30 to 200 μm.
Mold to about m. If the thickness of the green sheet of refractory powder is too thin, the strength of the film is weak and handling is poor, and if it is too thick, the amount of refractory material used increases and it is uneconomical.

The two kinds of green sheets prepared as described above are cut and laminated to have appropriate outer dimensions. When the glass ceramic substrate is a multilayer substrate, a conductor paste may be added if necessary. Etc. are printed. Then, one or a required number of glass-ceramic green sheets are stacked, and the refractory green sheets are arranged on both sides of the green sheets, and they are pressed and heated by a hot press machine or the like to be integrated. The pressure at that time is, for example, 50 to 300 kg / cm ² , and the temperature is 6
About 0 to 90 ° C is preferable. The same effect can be obtained by a laminating method in which the respective layers laminated as described above are adhered using, for example, a glue prepared by dissolving polyvinyl butyral in alcohol.

Next, the above-mentioned laminated body is, for example, 450-60.
After heating to about 0 ° C. to remove organic substances, the substrate is manufactured by firing at 1100 ° C. or lower, for example, 800 to 1100 ° C. At this stage, since the refractory powder is adhered to both surfaces of the sintered glass ceramic layer, the refractory powder can be removed from the substrate by rubbing with a brush or the like. In this case, if the colors of the glass ceramic layer and the insulating layer are different,
Removal of refractory powder can be easily confirmed visually. As the coloring means, for example, Cr ₂ O ₃ or Co ₃ O ₄ may be mixed into the glass ceramic or refractory layer.

According to the method for manufacturing a glass-ceramic substrate according to the present invention, the glass-ceramic layer is constrained by the refractory layer and hardly shrinks in the surface direction of the substrate but only in the thickness direction. It is possible to obtain an excellent substrate.

[0012]

EXAMPLE As a glass ceramic powder, glass powder (average particle size: 2.2 μm) having the composition shown in Table 1 below and alumina powder were mixed in a weight ratio of 50:50.

The refractory powder has an average particle size of 1.3 μm.
Of zirconium oxide was used. The slurry was prepared by adding 9 parts by weight of polyvinyl butyral, 7 parts by weight of diisobutyl phthalate, 1 part by weight of oleic acid, 40 parts by weight of isopropyl alcohol, and 20 parts by weight of trichloroethane to 100 parts by weight of glass ceramic powder and refractory powder, respectively. It was made by mixing in a ball mill for 24 hours.

Next, the above-mentioned two kinds of slurries were each formed into a sheet by a doctor blade method to prepare a glass ceramic powder green sheet and a refractory powder green sheet. The thickness is 118 μm and 131 μm, respectively
Met. Eight sheets of the obtained glass-ceramic green sheets were laminated, and both sides were sandwiched by refractory green sheets of the same size, and pressure molding was performed under the conditions of 150 kg / cm ² and 85 ° C. The molded body was heated at 520 ° C. for 3 hours to remove organic substances, subsequently baked at 900 ° C. for 1 hour, and then rubbed with a brush to remove the refractory powder to obtain a substrate.

Further, the specific surface area of the alumina powder in the glass ceramic substrate was changed to measure the shrinkage ratio in the surface direction of the substrate, and as a comparative example, the case of using a normal firing method without sandwiching a refractory sheet and the above-mentioned book. The case according to the embodiment of the invention was compared. The results are summarized in Table 2 below.

[0016]

As is clear from the above results, according to the manufacturing method of the present invention, the shrinkage rate during firing can be reduced as much as possible. Even when the raw material powder was changed, the maximum and minimum fluctuations of the shrinkage ratio of 6.73% appeared in the comparative example. However, according to the present invention, there is only a fluctuation of 0.07%, and the raw material having the greatest influence. It has been found that high dimensional accuracy can be maintained even with powder changes.

[0018]

As described above, according to the method for manufacturing a glass ceramic substrate of the present invention, the shrinkage rate during firing can be reduced as much as possible and high dimensional accuracy can be obtained even when the composition of the raw material is changed. It is possible to maintain high temperature, and it is possible to mass produce high quality glass ceramic substrates with high yield.

Claims (4)

[Claims] 1. At least a step of forming a green sheet made of glass ceramic powder as a raw material, a step of making a green sheet made of refractory powder as a raw material, and one or more sheets made of the above glass ceramic powder as a raw material. The step of molding by sandwiching both sides of the green sheet with the green sheet made of the above refractory powder as a raw material
A method for manufacturing a glass ceramic substrate, comprising: a step of firing at a temperature of ℃ or less; and a step of removing refractory powder from the fired body. 2. The method for producing a glass ceramic substrate according to claim 1, wherein the glass ceramic powder contains at least one of an amorphous glass powder and a crystallized glass powder. 3. The refractory powder is alumina, zirconium oxide, aluminum nitride, boron nitride, mullite,
The method for producing a glass ceramic substrate according to claim 1, wherein the glass ceramic substrate is one or more selected from magnesium oxide and silicon carbide. 4. The method for manufacturing a glass ceramic substrate according to claim 1, wherein the glass ceramic and the refractory powder have different colors.