JPS60109292A - Method of producing nonoxide ceramic circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a non-oxide ceramic wiring board (hereinafter referred to as wiring board).

Ceramic metallization methods include a thick film method, a thin film method, a plating method, and a high melting point metal baking method. Examples of metallization methods for oxide ceramics include gold, gold-platinum, silver,
It has been common practice to apply metallization paste, which is made by adding glass, a binder, and a solvent to precious metal powder such as silver-platinum or silver-palladium powder, onto ceramics and then bake it in air. However, when metallizing physically and chemically stable non-oxide ceramics using the above paste and the method shown above, bubbles etc. will occur in the conductor part and the conductor part and the substrate will become disconnected. Satisfactory adhesive strength and airtightness cannot be obtained. The surface solderability and bonding properties were still unsatisfactory.

The present invention has been made in view of the above points.

The object of the present invention is to provide a wiring board that does not generate bubbles or the like in conductor parts, has good adhesive strength and airtightness, and is satisfactory in terms of solder resistance and bonding properties.

The present invention is a non-oxide ceramic sintered body (hereinafter referred to as a sintered body) in which 100 parts by weight of noble metal powder with a particle size of 0.2 to 8 μm is mixed with 0.2 to 5 parts of glass powder with a softening point of 400 to 900°C. The present invention relates to a method for producing a wiring board, in which a metallizing paste for non-oxide ceramics, which is made by adding parts by weight, a binder and a solvent, is applied and then fired.

In the present invention, silicon carbide sintered bodies, silicon nitride sintered bodies, etc. are used as the non-oxide ceramic sintered bodies, and examples of the noble metal powders include gold powders and gold-platinum powders.

Silver powder, silver-platinum powder, silver-palladium powder, etc. are used, and although there are no particular restrictions, the particle size must be in the range of 0.2 to 8 μm, preferably 0.5 to 5 μm. If the particle size of the noble metal powder is less than 0.2 μm, bubbles etc. will be generated during firing and the adhesive strength will be weak, and if it exceeds 8 μm, sintering will not proceed much and the adhesive strength will also be weak.

There are no particular restrictions on the composition of glass powder, but? Now silicic acid system,
It is preferable to use zinc-lead glass or glass containing an oxide such as zirconia, alumina, or silica. However, its softening point must be in the range of 400-900°C, preferably 500-800°C. Softening point is 40
If the temperature is less than 0°C, blistering etc. will occur, and if it exceeds 900°C, the adhesive strength will become weak. Furthermore, the coefficient of thermal expansion is 2 to 6 x 1
It is preferable to use a glass powder of 0-6/6c because stable adhesive strength can be obtained.

The amount of glass powder added must be 0.2 to 5 parts by weight; if it is less than 0.2 parts by weight, the adhesive strength will be very weak, and if it exceeds 5 parts by weight, bubbles and blisters will occur. , the adhesive strength is weak.

9 In the present invention, examples of the binder include ethyl cellulose, nitrocellulose, and acrylic fljBW.

Epoxy resins and the like are used as solvents such as terpineol and carpitol acetate.

There are no particular restrictions on the composition, amount, etc. of these.

The paste is applied by a screen printing method, a square coating method, etc., and there are no particular restrictions on the firing conditions, but the paste must be fired at a temperature of 750 to 1050°C in an N9 atmosphere or in an air atmosphere. is preferred.

The present invention will be explained below with reference to Examples.

Example 1 0 to 10 parts by weight of various glass powders shown in Table 1 were added to a mixed powder of 80 parts by weight of silver powder having different particle sizes shown in Table 1 and 20 parts by weight of palladium powder having different particle sizes.

Furthermore, 6M ethyl cellulose and 40 parts by weight of terpineol were added as binders, and the mixture was uniformly mixed in a sieve machine to obtain a metallized paste.

Next, the metallization paste obtained above was screen printed on a silicon carbide sintered body (relative density of 90% or more) and a silicon nitride sintered body (relative density of 90% or more).

Then, the wiring board of the present invention was obtained by firing at a temperature in the range of 750 to 1100°C. Thereafter, a tin-plated lead wire was soldered to a copper wire having a diameter of 0.8 mm, and the lead wire was peeled off to conduct an adhesive strength test.

The external appearance was also observed. The test results are also shown in Table 1. In Table 1, the appearance refers to the microscopic observation of the metallized portion after firing.

υ, lower margin Example 2 1.0 to 7.0 parts by weight of the various glasses shown in Table 2 were added to 100 parts by weight of gold powder with different particle sizes shown in Table 2, and the same composition as in Example 1 was prepared. A metallized paste was obtained with the same composition and method.

Next, the metallization paste obtained above was screen printed on a silicon carbide sintered body (relative density of 90% or more) and a silicon nitride sintered body (relative density of 90% or more).

Then, the wiring board of the present invention was obtained by firing at a temperature in the range of 750 to 1100°C. Thereafter, an adhesive strength test and appearance 1 were observed in the same manner as in Example 1. The test results and the results of appearance observation are also shown in Table 2.

As can be seen from Tables 1 and 2, it can be seen that the wiring board of Example 1 of the present invention has good adhesive strength and appearance.

The wiring board of the present invention includes a sintered body mixed with 100 parts by weight of noble metal powder with a particle size of 0.2 to 8 μm, 0.2 to 5 parts by weight of glass powder with a softening point of 400 to 900°C, a binder, and a solvent. Since the metallizing paste for non-oxide ceramics is applied and then fired, no bubbles are generated in the conductor part, and it has good adhesive strength and airtightness, and also satisfies IT solderability and bonding properties. Become a kimono.

Claims (1)

[Claims] 1. Particle size of non-oxide ceramic sintered body is 0.2~8μ
100 parts by weight of noble metal powder with a softening point of 400 to 900°C
1. Production of a non-oxide ceramic wiring board characterized by applying a non-oxide ceramic metallizing paste made by adding and mixing 0.2 to 5 parts by weight of glass powder, a binder and a solvent, and then firing it. Law.