JPH03146488A - Production of aluminum nitride sintered body with metallizing layer - Google Patents

Abstract

PURPOSE:To firmly adhere an AlN sintered body and to produce the title sintered body with a metallizing layer having superior air tightness by applying and sintering specified metallizing paste to form the metallizing layer when the title sintered body is produced. CONSTITUTION:When the title sintered body is produced, the metallizing layer is formed by applying and sintering W-based metallizing paste contg. one or more kinds (e.g. nickel acetate powder) selected among Ni, Fe, Co, an Ni-Fe-Co alloy and compds. of these metals, one or more kinds (e.g. yttrium oxide powder) selected among Y, Gd and Ce compds., a mixture of these compds. and a Y-Gd- Ce compd. and an Al compd. (e.g. aluminum oxide powder).

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an aluminum nitride sintered body, which is attracting attention in many fields including IC insulating substrates, and particularly to a method for manufacturing an aluminum nitride sintered body having a metallized layer.

[Conventional technology]

Aluminum nitride (AIN) sintered body has thermal conductivity,
Due to its excellent electrical insulation and mechanical strength,
It is attracting attention in many fields including IC insulating substrates. However, the AIN sintered body has poor wettability with metal, and it is a problem to obtain a metallized layer with sufficient adhesion strength. Methods for forming the metallized layer include thick film firing method, DBC (Direct Bond Copper)
) method, thin film method, etc., and there are many successful examples. In addition, there are also successful cases of a simultaneous firing method in which a metallized paste is applied to an AIN sintered body and fired in a non-oxidizing atmosphere, and several cases have been reported. An example thereof is a composition and method for metallizing non-oxide ceramic bodies (Japanese Patent Publication No. 82-27037). This document discloses a composition that can provide strong adhesion that can be plated or brazed, as well as a metal surface finishing method using the same.In the case of AIN ceramic bodies, tungsten ( W) A metallizing composition containing, in addition to molybdenum (Mo), a constituent material of non-oxide ceramics, that is, AIN, and a metal or a metal oxide, and applying the paste to the AIN green body. , describes a simultaneous firing method in which firing is performed in a non-oxidizing atmosphere. There have been some reports of other examples, but satisfactory performance has not yet been achieved, such as poor airtightness. On the other hand, as a method for metallizing aluminum oxide (AlzOz) sintered bodies, W or molybdenum-manganese (M
o - M n ) metallized paste was applied and heated at 130° C. in a humidified hydrogen or humidified forming gas atmosphere.
The Telefunken method, which involves firing at a temperature of 0 to 1750"c, is widely known. The feature of this method is that it is fired in a humidified atmosphere to a temperature at which the glass phase in the Al2O3 sintered body softens. The surface of W and Mo is oxidized by firing, which not only promotes sintering of W or Mo particles, but also dissolves these oxides into the glass phase of the sintered body and improves the fluidity of the glass. The glass phase moves into the porous metallized layer.Furthermore, oxides generated by firing, especially MnO, form a glass phase near the interface between the metallized layer and the Al2O3 sintered body, so the metalized layer moves into the porous metallized layer. and Al2
The O3 sintered body is mechanically strongly bonded. [Problems to be Solved by the Invention] In view of the above circumstances, an object of the present invention is to provide an AtN sintered body having a metalized layer that firmly adheres to the AtN sintered body and has a high airtightness. It is something to do. [Means for Solving the Problems] In the production of an aluminum nitride sintered body having a metallized layer, the present invention provides that the metallized layer contains tungsten as a main component, nickel, iron, cobalt, their alloys, and their alloys. Obtained by applying and sintering a metallized paste containing one or more from the group consisting of compounds, one or more from the group consisting of yttrium compounds, cadrinium compounds, cerium compounds, mixtures thereof, and compounds and an aluminum compound. A method for producing an aluminum nitride sintered body having a metallized layer. That is, as a result of intensive studies to obtain an AtN sintered body having a metalized layer with high airtightness, the present inventors found that Wl:N
It has been found that an AtN sintered body having a metallized layer with extremely excellent airtightness can be obtained by adding one or more types from the group consisting of i5Fe, Co, alloys thereof, and compounds thereof. The above substance melts in a temperature range of 1600° C. or higher, where hermeticization of AIN occurs. Generally, in a reducing atmosphere, the sinterability of W is extremely poor because it does not involve mass transfer, but mass transfer occurs through these molten metals, and the sinterability of W is greatly promoted. , a dense metallization layer can be obtained. On the other hand, AIN has poor wettability with these molten metals, and a porous structure is formed near the interface between the metallized layer and the AtN sintered body. For this reason, it is not possible to obtain satisfactory values in terms of airtightness and adhesive strength between the metallized layer and the AtN sintered body. However, this problem could be solved by adding a substance with excellent wettability to both the metallized layer and the AtN sintered body. In particular, it has been found that the addition of one or more compounds selected from the group consisting of yttrium compounds, gadolinium compounds, cerium compounds, and mixtures and compounds thereof and an AI compound has a remarkable zero effect. An AtN sintered body having such a metallized layer is manufactured, for example, as follows. That is, first, an AIN green sheet is obtained by a conventional method. Thereafter, metallization paste is applied to predetermined portions of the AIN green sheet. This metallized paste has tungsten as its main component, and contains one or more of the group consisting of nickel, iron, cobalt, alloys thereof, and compounds thereof, and the group consisting of yttrium compounds, cadrinium compounds, cerium compounds, and mixtures and compounds thereof. It can be obtained by kneading a binder consisting of one or more of the above, an aluminum compound, a known binding agent such as ethyl cellulose, acrylic resin, or polyvinyl alcohol, and a known solvent such as α-terpineol or butyl calpitol. . By firing the green sheet coated with the metallization paste, sintering of AIN and formation of the metallization layer are performed simultaneously. The firing temperature at this time is preferably about 1600 to 2050°C. Further, as the atmospheric gas, nitrogen gas, dry forming gas, ammonia gas, etc. can be used, and it is also possible to mix hydrogen gas, helium gas, argon gas, -carbon oxide gas, etc. with this gas. As mentioned above, instead of applying the metallization paste to the AIN green sheet and then sintering the AIN and forming the metallization layer at the same time, which is the so-called simultaneous firing method, the metallization paste is applied to the AIN sintered body. It can also be applied to the so-called post-metallization method, in which a metallized layer is formed by coating and then firing. In this case, it is also possible to perform the firing in a vacuum. [Example] Next, Examples and Comparative Examples will be described. Example 1 AIN powder, yttrium oxide as a sintering aid, a mixture of polyvinyl butyral and polyvinyl alcohol as a binder, dibutyl phthalate (D, B, P
A mixture of benzyl butyl phthalate (B, B, P), menhenden fish oil as a deflocculant, a mixture of trichloroethylene, ethyl alcohol, and methyl ethyl ketone as a solvent, glycerin monooleate as a wetting agent, and an antifoaming agent were mixed in a ball mill. , a slurry was prepared. ′
This slurry was defoamed, and a green sheet of AIN was produced by a doctor blade method. On the other hand, a vehicle was prepared by mixing a binder such as polyvinyl alcohol, polymethyl methacrylate, and ethyl cellulose, and a solvent such as butylcarpitol and α-terpineol. After that, tungsten powder, nickel acetate powder, yttrium oxide powder, aluminum oxide powder and vehicle were polymerized at a polymerization ratio of 0: o, a: 10: 8.
: 25 to prepare a metallized paste. The metallized paste thus produced is applied to an AIN green sheet by a method such as screen printing. Thereafter, the binder was removed and fired in an H2/N2 atmosphere to obtain an AIN sintered body having a metallized layer. When this metallized layer was then tested for helium leakage, the leakage rate was 1 x to-a ee a
It was confirmed that the airtightness was good at ta+/see or less. After that, 2ffla+ of the obtained sintered body
After applying nickel plating to the 0 part and annealing it at 835℃, we soldered the wire and conducted a tensile strength test, and the result was 5.5 to 6.2 kg/2m+o, a level that would pose no problem in practical use. Met. Example 2 A green sheet and vehicle of AIN were produced by the method shown in Example 1. Thereafter, tungsten powder, ferrous oxide powder, gadolinium oxide powder, aluminum oxide powder, and vehicle were mixed in a Wjl ratio of 100:2:9:5:25 to prepare a metallized paste. The metallized paste thus prepared was applied by the method shown in Example 1, and then the binder was removed in an N2 atmosphere, and the AIN was baked in a H2/Nz atmosphere. A sintered body was obtained. When a helium leak test and a tensile strength test were conducted according to the method shown in Example 1, lx 10'ac ats/
See or less was 4.9 to 5.8 kg/2av mouth, which was a level with no practical problems. Example 3 A green sheet and vehicle of AIN were produced by the method shown in Example 1. Thereafter, tungsten powder, cobalt powder, cerium oxide powder, aluminum lactate powder, and vehicle were mixed in a weight ratio of 100:0, s:5:25:28 to prepare a metallized paste. The metallized paste thus prepared was applied by the method shown in Example 1, and then baked in a vacuum in an Ar/Nz atmosphere to remove the binder. Obtained a body. When a helium leak test and a tensile strength test were conducted according to the method shown in Example 1, LX 1G11 cc atIl/s was obtained, respectively.
ee or less was 5.3 to 5.7 kg/2ssO, which was a level with no practical problems. Comparative Example 1 A green sheet and vehicle of AIN were produced by the method shown in Example 1. Thereafter, tungsten powder, cerium oxide powder, aluminum oxide powder and vehicle were mixed in a weight ratio of 100:
A metallized paste was prepared by mixing at a ratio of 5:10:25. The metallized paste thus prepared was applied by the method shown in Example 1, and then the binder was removed and fired in an N2 atmosphere to form an AIN layer with a metallized layer.
A sintered body was obtained. When a helium leak test and a tensile strength test were conducted according to the method shown in Example 1, the results remained at Ix to' cc atl/see, respectively.
It remained at an extremely low level of 0.8 to 1.7 kg/2IIm. Comparative Example 2 A green sheet and vehicle of AIN were produced by the method shown in Example 1. Thereafter, tanmethane powder, iron powder, aluminum oxide powder, and vehicle were mixed in a l1tl ratio of 100:3:
A metallized paste was prepared by mixing at a ratio of 3:23. The metallized paste thus prepared was prepared in Example 1.
After coating and binding using the method shown in 1., binder removal was performed in a H2/N2 atmosphere, and firing was performed in a Co/N2 atmosphere to obtain an AIN sintered body having a metallized layer. Example 1
When a helium leak test and a tensile strength test were conducted using the method shown in
Although it was at■/see, it was 1.3 to 1.9 kg7
It remained at an extremely low level of 2 mg+'. [Effects of the Invention] According to the present invention, it is possible to obtain an AIN sintered body having a strongly bonded and highly airtight metallized layer, which can be used as a substrate material or package material, especially multilayer wiring that requires heat dissipation properties. It is extremely useful as a substrate material.

Claims (1)

[Claims] In the production of an aluminum nitride sintered body having a metallized layer, the metallized layer contains tungsten as a main component, one or more from the group consisting of nickel, iron, cobalt, alloys thereof, and compounds thereof, and an yttrium compound, Cadolinium compounds and cerium compounds and mixtures thereof,
1. A method for producing an aluminum nitride sintered body having a metallized layer, the method comprising applying and sintering a metallized paste containing one or more compounds from the group consisting of aluminum compounds and an aluminum compound.