JPS6185704A - Manufacture of metalized paste for ceramics - 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 (Field of Industrial Application) The present invention relates to a method for producing a metallized paste for ceramics that provides a metallized layer that is dense, has high adhesive strength to ceramics, and has a smooth surface.

For forming fine wiring or attaching various parts to the surface of ceramic substrates used for semiconductor integrated circuit boards, electronic circuit boards, etc., a metalized layer with high adhesive strength to ceramics and a dense and smooth surface is used. is necessary.

(Prior art and its problems) Conventionally, methods for forming such a metallized layer include M□,
M□-pJIH metallization method, W metallization method, Ag, P
d.

There is a thick film method that uses a thick film paste that is a mixture of noble metal powder such as Au and glass powder. In these methods, M
Mn in metal powders such as o, W, Ag, Pd, and Au.

It is common to add an inorganic binder powder such as glass powder, an organic binder, and a solvent, and make it into a paste using a sieve machine or a three-roll mill. However, since pasting is carried out under conditions of high viscosity, it is difficult to sufficiently convert the agglomerated powder into primary particles. It is also difficult to obtain a good mixing dispersion. When a metallized layer is formed using such a paste with insufficient mixing and dispersion, there are disadvantages in that a dense metallized layer with a smooth surface cannot be obtained, and the adhesive strength is low and variations are large. .

(Objective of the Invention) It is an object of the present invention to solve the above-mentioned drawbacks of the prior art, to fully disintegrate metal powder and inorganic binder powder into single particles in an organic binder solution, and to The present invention provides a method for producing a uniformly dispersed metallizing paste for ceramics.

(Structure of the Invention) The present invention provides a method for producing a metallizing paste for ceramics in which a metal powder, an inorganic binder powder, an organic binder, and a solvent are mixed. The viscosity of the metal powder and the inorganic binder powder are below the level that does not prevent the disintegration of the metal powder and the inorganic binder powder, and an amount of the organic binder is added that prevents the disaggregated particles from coming into direct contact with each other.
Mix and disintegrate the metal powder and inorganic binder powder until they become single particles, and then remove the solvent to obtain a mixed powder in which the surfaces of the metal powder and inorganic binder powder are coated with an organic binder9.
Next, the present invention relates to a method for producing a metallizing paste for ceramics, which involves adding and mixing a solvent in an amount necessary for forming a paste.

In the present invention, metal powders include high melting point metal powders such as Mo and Wl, and noble metal powders such as Ag@pal Au.

Powders of base metals such as Cu and N1 are used, and there are no particular limitations, but it is preferable to use powders of relatively hard and low ductile high-melting metals such as Mo and W. In addition, as an inorganic binder powder,
Mn powder, alumina, silica, magnesia, calcia oxides, glass powders made of one or more of these oxides, and silicic acid-based oxides.

Zinc-lead glass may be used, and there are no particular limitations.

The selection may be made depending on the type of metal powder used and the type of ceramic forming the metallized layer.

In the present invention, ethyl cellulose, nitrocellulose, acrylic resin, butyral resin, etc. are used as the organic binder, and if necessary, a beautifying agent such as phthalate ester or triethylene glycol may be added. Ethyl acetate as the solvent.

hH7'fl, tI) Chlorethylene, toluene.

One or more mixed solvents such as xylene, methyl ethyl ketone, ethanol, and methanol are used.

The viscosity of the mixture of metal powder, inorganic binder powder, organic binder, and solvent is preferably 20P (voids) at maximum, and more preferably in the range of IP to 5P. Further, the amount of the organic binder added is preferably 0.5 to 6 parts by weight, more preferably 1 to 4 parts by weight, per 100 parts by weight of the metal powder.

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

Example 1 Mo powder 100 with an average particle size of 0.63 μm as metal powder
Average particle size of inorganic binder powder is 1.5μ per part by weight.
1 part by weight of Mn powder, 3 parts by weight of glass powder consisting of alumina, silica, magnesia, and calcia, 2 parts by weight of ethyl cellulose and 2 parts by weight of nitrocellulose as organic binders, and 1:1 of ethyl acetate and toluene as solvents.
200 parts by weight of the mixed solution were mixed in a ball mill for 20 hours to fully disintegrate the metal powder and inorganic binder powder into single particles.
of slurry was obtained. Next, the slurry was dried while being heated and mixed in a sieve machine, and the solvent was removed to obtain a mixed powder in which the surfaces of the whole area powder and the inorganic binder powder were coated with an organic binder.

Next, based on 108 parts by weight of the mixed powder obtained above.

40 parts by weight of terpineol was added as a solvent.

After mixing for 2 hours in a milling machine, the mixture was made into a paste in a three-roll mill to obtain a metallized paste for ceramics.

The obtained metallized paste for ceramics was screen printed on a SiC substrate (manufactured by Hitachi, Ltd., trade name 5C-101), and then fired at 1300° C. in a weakly reducing atmosphere to form a metallized layer on the 8iC substrate. The surface roughness of the obtained metallized layer was 3. With OpmBx, the adhesive strength with the SiC substrate is 4. It was more than Okgf/am1.

On the other hand, as a comparative example, fC,
1 part by weight and 3 parts by weight of Mn powder and glass powder, 2 parts by weight of ethyl cellulose and 2 parts by weight of nitrocellulose as organic binders, and 40 parts of terpineol as a solvent.
Parts by weight were weighed, mixed for 5 hours using a sieve machine, and then made into a paste using a three-roll mill without disintegrating the Kinmen powder and the inorganic binder powder into single particles. Using the obtained paste, a metallized layer was formed on a SiC substrate (manufactured by Hitachi, Ltd., trade name 5C-101) through the same steps as in Example 1. The surface roughness of the obtained metallized layer was 6
μm Adhesion strength FiZ between RZ and rough < , SiC substrate
Okgf/am'' was lower than that of Example 1, and the variation was large.

Example 2 To 100 parts by weight of W powder with an average particle size of 1.2 μm as gold powder, 1 part by weight of the glass powder used in Example 1 as inorganic binder powder, 1 part of ethyl cellulose 11 and nitro as organic binder. Weighed 1 part by weight of cellulose and 150 parts by weight of a 1:1 mixture of ethyl acetate and toluene as a solvent, mixed and granulated in the same manner as in Example 1, and obtained a uniformly dispersed viscosity of 4P. Got slurry. Next, the slurry was dried in the same manner as in Example 1, and the solvent was removed to obtain a mixed powder in which the surfaces of the metal powder and inorganic binder powder were seeded with an organic binder.

Further, based on 102 parts by weight of the mixed powder obtained above.

35 parts by weight of terpineol was added as a solvent and the mixture was made into a paste in the same manner as in Example 1 to obtain a metallized paste for ceramics.

On the other hand, 96 parts by weight of alumina, 1.5 parts by weight of magnesia powder as a sintering aid, 25 parts by weight of glue, 6 parts of butyral resin as an organic binder, 3 parts by weight of butylbenzyl phthalate as a plasticizer, and ethanol as a solvent. After adding 40 parts by weight of an azeotropic mixture of and trichlorethylene and mixing in a ball mill for 24 hours, tape casting was performed.

Ceraminoku green root was obtained.

The ceramic metallization paste obtained above was printed on the obtained ceramic green/sheet.

It was fired at 1,540° C. in a weakly reducing atmosphere to form a metallurgical layer on the alumina ceramics. The surface roughness of the obtained metallized layer was z5 μm 2, and the adhesive strength with alumina cerami and Nox was 7.0 kgf/an' or more.

In contrast, as a comparative example, 100 parts by weight of the W powder used in Example 2, 1 part by weight of the glass powder used in Example 1, and 11 parts by weight of ethyl cellulose as an organic binder. 1 part by weight of nitrocellulose and 35 parts by weight of terpineol as a solvent were mixed in a sieve machine for 5 hours to dissolve the metal powder and inorganic binder powder without disintegrating them into single particles. It was made into a paste using this roll.

The obtained paste was subjected to the same steps as in Example 2 to form a metallized layer on alumina ceramics. The surface roughness of the obtained metallized layer is as rough as 7 μm Rz, and the adhesive strength with alumina ceramics is 2.5 kg f10! In
', and the variation was wide.

In the embodiments of the present invention, the materials were mixed and pulverized using a ball mill, but similar effects can be obtained by using a miller or other mixing methods.

(Effects of the Invention) The present invention provides a method in which the viscosity of a mixture of metal powder, inorganic binder powder, organic binder and solvent is below a level that impedes disintegration of the metal powder and inorganic binder powder.

Add and mix an organic binder in an amount that prevents direct contact between the disintegrated particles, disintegrate the metal powder and inorganic binder powder until they become single particles, and then remove the solvent to form the metal powder. The surface of the inorganic binder powder is coated with an organic binder to form a mixed powder, and then the necessary amount of solvent is added and mixed to form a paste, resulting in a dense metal with high adhesive strength to ceramics and a smooth surface. A metallizing paste for ceramics can be produced that provides a hardening layer.

Claims (1)

[Claims] 1. In the method for producing metallized paste for ceramics, which mixes metal powder, inorganic binder powder, organic binder, and solvent, the viscosity of the mixture of metal powder, inorganic binder powder, organic binder, and solvent is that of metal powder. The metal powder and the inorganic binder powder are combined into single particles by adding and mixing an organic binder in an amount that does not interfere with the disintegration of the inorganic binder powder and prevents direct contact between the disintegrated particles. After that, the solvent is removed to obtain a mixed powder in which the surface of the metal powder and inorganic binder powder is coated with an organic binder, and then the amount of solvent necessary for making a paste is added and mixed. Features: A method for producing metallized paste for ceramics.