JPS62143890A - Aluminum nitride sintered body with metallized surface - 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 an aluminum nitride sintered body, and more specifically, an aluminum nitride sintered body having a metallized surface with reliable and practical bonding strength. It is related to.

2. Description of the Related Art Semiconductor devices and devices and equipment using them generally include various active and passive elements, but these have the problem of heat generation. Therefore, in order to operate these elements stably and reliably, it is necessary to perform the best thermal design during mounting, which is extremely important in the design and manufacture of semiconductor devices and the like.

Furthermore, in recent years, there has been a major trend toward faster operation and higher integration of semiconductor devices, and in particular, there has been a remarkable increase in the integration density of LSIs and the like. Along with this, the amount of heat generated per package also increases significantly. For this reason, importance has been placed on the heat dissipation properties of substrate materials.

On the other hand, alumina has traditionally been used as ceramics for IC boards, but the thermal conductivity of conventional alumina sintered bodies is insufficient for heat dissipation, and it is no longer able to adequately cope with the increase in heat generation of IC chips. It's coming. Therefore, as an alternative to such alumina substrates, substrates or heat sinks using aluminum nitride, which has high thermal conductivity, have attracted attention, and many studies have been conducted to put them into practical use.

Aluminum nitride is a material that inherently has high thermal conductivity and high insulation properties, and unlike aluminum nitride, it is non-toxic, so it is viewed as a promising material in the semiconductor industry, especially as an insulating material and packaging material. There is.

Aluminum nitride (AIN) sintered bodies have high thermal conductivity, so as mentioned above, they are used as substrates for integrated circuits (ICs).
It is also attracting attention as a heat sink. However, while having such interesting properties, the HEIN sintered body has a problem in bonding strength with metals, glass, etc. By the way, this sintered body can be coated with a metallized layer by using a thick film method in which a commercially available metallizing paste is directly applied to the surface of the sintered body, or a thin film method in which a thin film of active metal or metal is formed by vapor deposition or other methods. It is generally used in the state where it is attached. However, it is not possible to obtain a bonding strength sufficient for practical use by such a method, and in reality, the surface is modified by some method before or during metallization, and other methods such as It is necessary to improve bondability with metals, etc.

As a conventional method for surface modification of such an AIN sintered body, a method is known in which the surface of the AIN sintered body is subjected to oxidation treatment or the like to form an oxide layer. That is, for example, AIN
SiO3, Al2O3, mullite, I'e on the surface of the sintered body
203, a method of forming an oxide layer such as CuO. However, the oxide layer as exemplified above is a glass layer,
Although it has a good affinity for the alumina layer and the like and forms a strong bond, it has a low affinity for the AIN sintered body itself and is considered to have a reliability problem.

Problems to be Solved by the Invention As mentioned above, since it has extremely good electrical insulation and thermal conductivity, it is expected to be used as an IC insulating substrate and heat sink material that requires good heat dissipation. The bodies are often used with their surfaces metallized, but there have been problems in terms of bonding strength to these. Therefore, various methods such as those described above have been considered, but all of them are insufficient, and no IN sintered body having a metallized surface sufficient for practical use has been obtained so far.

That is, good bonding strength could not be obtained by the conventional thick film method of applying a metallized paste (for example, a commercially available frit or chemical bond type) to an IN sintered body. This is because the conductive paste is originally for A1□03 and does not have good reactivity with the AIN layer.

Furthermore, oxide treatment of the surface of an AIN sintered body is known, in which a method is known in which metallization is performed while or after the oxide layer is formed. However, the above SiO2
, Δ1□03, mullite, FezO3, CuO, etc. The oxide layer i7 has poor reactivity with IN. Moreover, even if a reaction layer is formed, since the reaction layer is essentially similar to an oxide layer, the reactivity with the AIN surface will hardly be improved, and therefore the bonding with the AIN sintered body will be difficult. Strength is also not improved. Furthermore, this oxide treatment has problems in terms of density and film bonding strength. That is, the oxide treatment of the AIN surface is expressed, for example, by the following formula: 2AIN+-0□ → A1□03+N2 Nitrogen gas may be generated as a result of this reaction, and the resulting oxide film is extremely porous. It becomes a film of quality.

Further, it is difficult to expect sufficient bonding strength even by thick film methods or thin film methods using active metals.

In other words, even when active metals that are highly reactive with silicides are used, 8IN is extremely chemically stable, so sufficient bonding strength cannot be obtained between them, making bonding difficult. This seems to be due to the following.

All of the various attempts to achieve a bond strength sufficient for practical use between the AIN sintered body and the metallized layer as described above have all failed.

Therefore, elements or compounds that have an affinity for both the metal layer or metal oxide, etc. and the AIN sintered body have been developed to ensure the bond between the metallized layer and the AIN sintered body.
The development of new technology that can improve the bonding strength of sintered bodies is strongly desired.

Therefore, an object of the present invention is to improve the bonding strength between a metallized layer and an AIN sintered body, which has poor insulation and heat dissipation properties. That is, the object is to provide an IN sintered body having excellent bonding strength and a highly reliable metallized surface.

Means to Solve the Problems In view of the current state of the above-mentioned conventional methods for improving the bonding strength between the metallized layer and the AIN sintered body, the inventors have conducted various studies and research to develop new techniques. As a result, it was found that it is effective to provide an intervening layer of a specific material between the AIN sintered body and the metallized layer, or to mix a specific material into the metallized layer in advance, and The present invention was completed based on new findings.

That is, according to one embodiment, the AIN sintered body having a metallized surface of the present invention comprises an AIN sintered body, a metallized layer thereon, and boron (B) or a compound thereof between the AIN sintered body and the metallized layer thereon. It is characterized by comprising an intervening layer containing.

According to another aspect of the present invention, the AIN sintered body having a metallized layer of the present invention includes an AIN sintered body and a metalized layer provided thereon to which B or a compound thereof is added/mixed. ,
It is characterized by being composed of an intervening layer containing B or a compound thereof formed between these.

In the first aspect of the present invention, the metallized layer material is gold (Au), gold (80)-platinum (Pt), platinum (Pt
), silver (Ag) or Ag-palladium (Pd) thick film paste (first group), or also copper (Cu), tungsten (W) or molybdenum (Mo), molybdenum. )-Manganese (Mn) thick film paste (second group) can be cited as a preferable example. For the first group, these materials can be made into a metallized layer by first applying the thick film paste in an air atmosphere, in an acidic gas stream, or in a nitrogen atmosphere, and then firing. A metallized layer can be obtained by similarly applying a thick film paste under a non-oxidizing atmosphere, a weakly reducing atmosphere, or a humid atmosphere (humidity 10% or less) and firing it.

In this case, the intervening layer formed consists of B or a compound thereof and the metallized layer-forming material and/or A for the sintering operation.
It may be present as a reaction layer with the IN substrate and/or as a diffusion layer and/or as a mixed layer, or as a layer of B or a mixture alone during production.

Further, the metallized layer is formed by forming B or a compound thereof on the surface of the IN sintered body, and then forming active metals such as titanium (TI), zirconium (Zr), or hafnium 01r) with high affinity for B (from the periodic table). Group IVa elements) as the innermost layer, followed by MO, nickel (Ni), or T
It can also be obtained by depositing i or Zr, then Pt, and then ^U by a thin film formation method. In this case, there are no particular restrictions on the thin film forming method, such as vacuum evaporation,
The method can be appropriately selected from chemical vapor deposition (CVD), plasma CVD, sputtering, ion plasma noting, J-on evaporation thin film formation (IVD), etc., depending on the material, type, etc.

In the first embodiment described above, B or its compound can be formed on the surface of the AIN sintered body by a thick film method or a thin film method. More specifically, B alone or a compound thereof can be deposited by a spray method, screen printing method, vacuum deposition method, chemical vapor deposition method, physical vapor deposition method, ion implantation method, etc., and the thickness is not particularly limited. Preferred examples of the B compound include boron oxide, aluminum boride, boron nitride, aluminum borate, titanium boride, and zirconium boride. These can be used as a mixture, and of course can also be used alone or in combination.

According to another aspect of the invention, the metallization layer material may be U18U-Pt, Pt, Hemi or Ag-
Pd thick film paste and C's W, Mo or Mo
Preferred examples include Mn thick film paste. These materials contain B or its compound in an amount of 0.01 of the total metal weight in the paste.
It is preferably 10% by weight. The thick film paste containing B or its compound is directly applied onto the surface of the 1N sintered body and then fired to form a two-layer structure.

However, in reality, B or its compound diffuses and reacts during firing of the thick film paste, and an intervening layer is formed as a diffusion layer and/or reaction layer containing B or its compound, and in reality, three layers are formed. It becomes a structure. Furthermore, in this embodiment as well, it is of course possible to apply B or its compound to the AIN surface in advance as in the first embodiment, and then apply a paste containing this thereon and then bake it.

The ΔIN sintered body having the metallized surface of the present invention described above is
The structures are as shown in the attached FIGS. 1(a) and 1(b), respectively. FIG. 1(a) is a schematic cross-sectional view of the first embodiment of the present invention, that is, an example having a three-layer structure.
An AIN sintered body 1, a metallized layer 2, and a reaction layer and/or a diffusion layer and/or a reaction layer between an B element or a compound layer of B and a metallized layer and/or an IN substrate interposed therebetween.
Alternatively, it is formed with an intermediate intervening layer 3 composed of a mixed layer. On the other hand, according to the second aspect of the present invention, as shown in FIG. a third layer 3 different from the AIN sintered body 1 and the metallization layer 2''
' (interface layer) to ensure adhesion and compactness between them, and to guarantee the strength of the AIN sintered body.

Furthermore, the AIN sintered body as a substrate useful in the present invention can be produced by any conventionally known method;
Since the powder itself has extremely poor sinterability, the AIN sintered body obtained by sintering after powder compaction often has a large amount of pores and has poor thermal conductivity. This is because the heat conduction mechanism of insulating ceramics such as ΔIN sintered bodies is mainly based on phonon conduction due to anharmonic interaction between lattice vibrations because this AIN consists of ionic bonds and covalent bonds. This is due to the fact that when there are a large number of defects such as pores and impurities, phonon scattering is significant and only a low thermal conductivity can be obtained.

Therefore, it is preferable to use a material obtained by the method for producing a dense IN sintered material having good thermal conductivity developed by the present inventors. In this method, a solution of at least one selected from the group consisting of yttrium (Y) and cerium (Ce) alkoxides is added to AIN powder with an oxygen content of 1.8% by weight or less in terms of Y or Ce.
~10% by weight was added, mixed and decomposed, then molded, 170% by weight.
It consists of normal pressure sintering in a non-oxidizing atmosphere at a temperature within the range of 0 to 2200°C (see Japanese Patent Application No. 184635/1986). However, the material is not limited to this example, and is not particularly limited as long as it is dense and has good thermal conductivity.

Due to its excellent insulating properties and thermal conductivity, Xushi AIN sintered bodies are suitable for use in semiconductor devices, especially highly integrated IC chips, insulating substrates for high-speed operation, high-frequency operation, high heat generation elements, or semiconductors such as heat sinks. It was seen as a promising packaging material. However, this AIN sintered body is insufficient in terms of its bonding strength, and despite much research to improve this point, it is fully satisfied.
So far, nothing that can be put to practical use has been obtained.

By the way, the problem of the bonding strength of this AIN sintered body is that
This problem can be advantageously solved by devising the method of the present invention when metallizing the IN sintered body.

In general, metals have a high affinity for oxygen, but A
Since IN is obviously a nitride, when a metallized layer is provided on it, it is possible to interpose a metal/total oxide and a single element or a compound of an element having an affinity for nitrogen at the interface between the two. It is thought that it is possible to firmly combine the two. From this technical standpoint, the present inventors came to the conclusion that B or its compound is effective, and completed the present invention.

In other words, the known intervening layer on the AIN surface is almost always an oxide, and in this study, among those that have high chemical affinity for both metals/metal oxides and nitrides, B alone or its compounds are particularly important. B atoms or their ions are small compared to most atoms and ions, and are easily diffused and implanted into the metallization layer and into the substrate, and even react with the substrate material and the metallization layer material. This seems to ensure sufficient bonding strength between them.

There are two main methods to form the B compound on the interface of the AIN sintered body and the metallized layer. A strong bond is achieved by forming a layer of the element or its compound, through which a metallization layer is applied. Another method can be realized by adding and mixing B element or its compound into a metallized layer forming paste in advance, applying this directly to the IN sintered body, and firing it. In either case, the B in the B element or its compound diffuses into the AIN and/or the metallization layer and optionally reacts to form a diffusion layer and/or a reaction layer. As a result, the bond between the AIN sintered body and the metallized layer becomes strong, and an AIN sintered body substrate or the like having a metallized surface that is sufficiently suitable for practical use can be obtained.

In particular, in the thick film paste method using B or B compound-containing metallization paste, Ag is used as the paste material when firing in an atmospheric atmosphere.

It is preferable to use Pt5Au-Pt, Au, Ag-Pd pastes, W, lAo, Mn for firing under a humidified hydrogen cloud atmosphere, and Cu for nitrogen S snow surroundings.
Preferably, a paste is used. In this case, the amount of B or its compound added to the paste is preferably 0.01 to 10% by weight of the total metal weight present in the paste as described above. This is because if the amount of B or its compound exceeds 10% by weight of the total metal weight, there will be no problem in terms of adhesive strength between the AIN sintered body and the metallized layer, but there will be problems in other respects such as wire bondability. This is because the interesting properties of high insulation and high thermal conductivity cannot be utilized. On the other hand, if the content is less than the lower limit of 0.01% by weight, the desired sufficient bonding strength cannot be obtained.

Thus, various advantages can be obtained by interposing B alone or a compound thereof between the AIN sintered body and the metallized layer as in the present invention. That is, first, they provide a uniform, dense, and strong bond between the two. This is because B or the B compound provides good wettability to AIN as well as metals, oxides, glass, etc., and as a result, high adhesive strength is obtained.

Therefore, the AIN sintered body having a metallized surface of the present invention can be applied to all fields that require the use of a material that has both high heat dissipation and high insulation properties, and is particularly applicable to insulating substrates for ICs, etc. It can be used advantageously for heat 7 tanks, etc.

EXAMPLES Hereinafter, the ΔIN sintered body having a metallized layer of the present invention will be explained in more detail and its usefulness will be demonstrated using examples, but the sintered body of the present invention is not limited in any way by the following examples. .

Example 1 After coating 8203 with a thickness of 1.5 μm on the surface of an IN substrate by a powder spray method, it was baked at 800° C. for 30 minutes in an air atmosphere. Next, a 3-Pd, 83 conductor paste was applied to the surface by screen printing on a 1-layer square U1 of about 25 μm, and then baked at 920° C. for 10 minutes in an oxygen stream. The thus obtained AIN with metallized surface
A wire (copper wire 1 mmφ) was welded to the sintered body by soldering, and the tensile strength at that time was measured.

The results were as follows.

8. Haste 2.2
Kg/mm28g-Pd paste
2.4Kg/mm28g paste
2.0Kg 7mm2 For comparison, apply the paste directly on the ΔIN board as above,
When fired, the tensile strength was 0.
4Kg/mm2, Ag-Pd paste: 0.5Kg
/mm2, and the Ag paste was 0.2Kg/mm2.

Example 2 Sumitomo Metal Mining Co., Ltd. 8g-Pd Pace) (ttC
1160) was added with 1% B metal or 3% B2O3 by weight and mixed thoroughly.

The thus obtained B-containing paste was applied to a thickness of about 15 μm on a AIN sintered body substrate, and then fired at 930° C. for 10 minutes in an oxygen stream to obtain an AIN sintered body having a metallized surface according to the present invention. Ta. The tensile strength measured in the same manner as in Example 1 was as follows.

1% B-containing paste 2. IKg 7mm23%
B2O3 containing paste 2.4Kg 7mm2 Meanwhile, A
The above Δg- which does not contain B or its compound on the IN substrate
The tensile strength of the product obtained by directly applying Pd paste and firing was 0.6 Kg/mm2.

Example 3 B and Ti were applied to the surface of the IN substrate using the ion plate ink method.
, Mo and N1 respectively 0.5.1.1, in this page introduction.
It was coated to a film thickness of about 0.8 and 1.9 μm.

The tensile strength of the IN sintered body having the metallized surface thus obtained was similarly measured and found to be 4.8 kg and 7 mm2. Furthermore, the following products were produced in the same manner and their tensile strengths were measured.

B/Ti/Pt/ΔuO05,1,1,0,7 and 1
．． 8 μm (4,9Kg/mm2)B/Zr/Mo/
NiO, 4,1,3,0,8 and 1.9 pm (
4,2Kg/mm2)B'/Iff/Mo/NiO,
4,1,2,0,8 and 1.7 μm (2,9Kg
/mm2)B/Iff/Pt/Au O,4,1,1,
0.7 and 1.8 μm (2.5Kg/mm2) On the other hand, B, Zr, Pt and 8u were similarly prepared in this order with film thicknesses of 0.4.1, 3.1.0 and 2.1 μm, respectively. When the tensile strength of the resulting product was measured, it was found to have a good strength of 3.9 kg and 7 mm2. For comparison, coatings with the following configuration were applied and the tensile strength was measured in the same manner.

Ti/Mo/Ni each 1.1.0.8.1.9 μm
(1.1Kg/mm2) Zr/P and U each 1.
2, 0.8, 1.9 μm (0.9Kg 7mm2
) Ti/Pt/8ul, 0.7 and 1.8 pm to L
(0.7Kg 7mm2) Zr/Mo/Ni 1.2
．． 0.8 and 1.9μm (0.6Kg/mm')H
f/Mo/Ni 1.2.0.8 and 1.9 μm (
0.4Kg/mm2)+1f/Pt/8u1,1.0.
7 and 1.8 μm (0.3 Kg/mm2) Example 4 After applying B metal with a thickness of 1.8 μm to the IN substrate, 9
Baking was performed at 50° C. for 10 minutes in a nitrogen atmosphere. Then, similar to Example 1, 5 types (Au, Δg-Pd) were applied to the surface.
A conductive paste of SPt, Au-Pt and Ag) was applied and fired at 800°C for 30 minutes. Each was measured using a wire bond (gold wire φ30 μm) method. 9, 8.11
．． It was 1.10.6.9.7.11.4g. Also,
As a comparative example, similar measurements were conducted on a product obtained by directly applying and firing the paste without applying B metal, and the following results were obtained.

Comparative example: Ishun-3.1g, 8g-Pd=2.9g, P
t=3.4g.

8u-Pt = 2.6g, 8g = 2.1g.

Note that this value is generally required to be 6 g or more for practical purposes.

Example 5 WSMo-Mn and Cu pastes were applied to a thickness of about 18 μm by screen printing on the surface of the IN substrate coated with Al82 in the same manner as in Example 1. These samples were then fired for 30 minutes at 1640, 1430 and 820° C., respectively, in a humidified hydrogen stream. The tensile strength of the obtained products is 1.4, 1.8 and 2.3 Kg / m, respectively
It was m,'. For comparison, each paste was directly applied and fired without using Al82. The tensile strength was as follows.

Comparative example: W=0.3Kg/mm2, Mo-Mn=0.
6Kg/mm2, Cu = 0.4Kg/mm2 Example 6 °rW pace manufactured by Sahi Chemical Research Institute Co., Ltd.) (ttWΔ-
1200> was added with B corresponding to 1.2% of its weight, and thoroughly mixed to obtain a B-containing W paste.

This paste was applied to the surface of the AIN green sheet in a single block of about 32 μm by screen printing, and then co-fired in a nitrogen atmosphere. Adhesion strength (tensile strength) is 2.
It was 4Kg and 7mm2. On the other hand, an example in which B was not used was also carried out, but the results were as shown in the above.

Comparative example: Adhesion strength 0.7Kg 7mm2゜Example 7 On the surface of the ΔIN substrate on which B was vapor-deposited to a thickness of 0.9 μm,
After implanting N+ by ion implantation at IXIO"1 ons/c, Ti, Mo and N1 were injected in this order at 1.
4. Deposited at thicknesses of 0.8 and 1.9 μm. Also,
An Ag-Pd paste was applied to the ion-implanted surface to a thickness of 24 μm by screen printing, and then baked at 910° C. for 10 minutes in an oxygen stream. The measured tensile strength of each sample was 6.1.2.8Kg 7mm2
Met. In addition, samples for comparison were obtained by processing in the same manner without using B, and the tensile strength was determined as shown below.

Comparative example; 8IN/T+/Mo/N+ 1.4.0.8.1.2
μm (1,1Kg/mm2) to IN/tog-Pd
(24μm) (0.4Kg/mm2) Example 8 B, BN, B2O3, A for 100 parts by weight of static coarse powder
I 20 s B 203, 8IB2, 8l B I
2. TiB2 or ZrB2 powder from 0.001 to
Add 20 parts by weight of ethyl cellulose as an organic binder to 100 parts by weight of these metal mixtures at a concentration of 5%.
A slurry-like Au paste prepared by adding and kneading a terpineol solution containing 20 parts by weight of The bonding strength with the metallized surface was determined by the wire bonding method (Au wire 30 mm φ), and the wire bonding property of the metallized surface was determined by wire bonding for the number of attempted wire bonds of the AU wire to the metallized surface. The number of samples obtained was expressed as a percentage and evaluated in three stages as shown in Table 1 below.

Example 9 Cu paste was added with 0.8 wt% of B1B2O3 or 8120. based on Cu metal powder.・After adding and mixing B2O3, this paste was applied to a thickness of about 14 μm on a 1N substrate using a screen printing method, and was printed in a nitrogen atmosphere for 61 hours.
It was baked at 5° C. for 10 minutes. Au plating was applied to the fired metallized surface to a thickness of about 1 μm, and the bonding strength was determined by the wire bonding method (AU wire 30 mmφ) in the same manner as in Example 8.

Further, as a comparative example, the Cu paste was similarly damaged without adding anything, metallized, and the wire bond value was determined.

Effects of the Invention Thus, according to the AIN sintered body having a metallized surface of the present invention, since the bonding strength is insufficient, although it has interesting high thermal conductivity and high insulation properties, it has high heat dissipation. AI was insufficient for practical use as an insulating substrate or heat sink for highly integrated ICs, or as an insulating material for various types of high-frequency and high-speed operation devices.
It has become possible to improve the bonding strength of N sintered bodies to the point where they can almost be put into practical use. This is done by interposing B or its compound between the metallized layer and the AIN sintered body, or after adding or mixing these into the paste, and then applying the metallized layer by a thick film method or a thin film method. Due to AI
This is based on the fact that the N and/or metallized layer and the B or its compound layer are strongly bonded by forming a diffusion layer and/or a reaction layer.

Further, since the metallized surface of the aluminum nitride sintered body according to the present invention has excellent wire bonding strength, it is extremely suitable as a substrate for semiconductor devices, etc., and as an assembly and mounting component of the device.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are schematic cross-sectional views for explaining two preferred embodiments of the aluminum nitride sintered body having a metallized surface according to the present invention. (Main reference numbers) 1...IN substrate, 2.2'...metalized layer, 3.3"...intervening layer

Claims (12)

[Claims] (1) Nitriding with a metallized surface characterized by being composed of an aluminum nitride sintered body, a metallized layer thereon, and an intervening layer containing elemental boron or a compound thereof formed between the aluminum nitride sintered body Aluminum sintered body. (2) The metallized layer is formed by firing a thick film paste of gold, gold-platinum, platinum, silver, or silver-palladium in air, oxygen atmosphere, or nitrogen atmosphere. An aluminum nitride sintered body having a metallized surface according to claim 1. (3) The metallized layer is formed by firing a thin film paste of copper, tungsten, molybdenum, or molybdenum-manganese in a non-oxidizing atmosphere, a weakly reducing atmosphere, or a humidified atmosphere. An aluminum nitride sintered body having a metallized surface according to claim 1. (4) A patent claim characterized in that the metallized layer is formed by a thin film method in which the innermost layer is a group IVa element of the periodic table, followed by molybdenum and nickel, or platinum and gold in that order. An aluminum nitride sintered body having a metallized surface according to item 1. (5) The aluminum nitride sintered body having a metallized surface according to claim 4, wherein the Group IVa element is Ti or Zr. (6) The above-mentioned boron or its compound is formed on the surface of the aluminum nitride sintered body by a spray method, screen printing method, vacuum deposition method, chemical vapor deposition method, physical vapor deposition method, or ion implantation method. An aluminum nitride sintered body having a metallized surface according to any one of the ranges 1 to 5. (7) The boron compound is boron oxide, aluminum borate,
The aluminum nitride sintered material having a metallized surface according to any one of claims 1 to 6, characterized in that it is aluminum boride, boron nitride, titanium boride, zirconium boride, or a mixture thereof. Body. (8) An aluminum nitride sintered body having a metallized layer, the metallized layer containing elemental boron or a compound thereof, and boron or its compound formed between the metallized layer and the sintered body. An aluminum nitride sintered body having the metallized surface described above, characterized in that it has an intervening layer comprising: (9) Aluminum nitride having a metallized surface according to claim 8, wherein the metallized layer contains boron or a compound thereof in an amount of 0.01 to 10% by weight based on the weight of the total metal present. Sintered body. (10) The metallized layer is formed by applying gold, gold-platinum, platinum, silver, or silver-palladium thick film paste containing boron or its compound to the surface of the aluminum nitride sintered body, in air or oxygen atmosphere. Alternatively, the aluminum nitride sintered body having a metallized surface according to claim 9 is obtained by firing in a nitrogen atmosphere. (11) The metallized layer contains copper, tungsten, molybdenum or molybdenum containing boron or a compound thereof.
Claim 8, characterized in that it is obtained by applying a manganese thick film paste to the surface of the aluminum nitride sintered body and firing it in a non-oxidizing atmosphere, a weakly reducing atmosphere, or a humidified atmosphere. An aluminum nitride sintered body having a metallized surface according to item 1 or item 9. (12) Any one of claims 8 to 11, wherein the boron compound is boron oxide, aluminum borate, aluminum boride, boron nitride, titanium boride, zirconium boride, or a mixture thereof. An aluminum nitride sintered body having a metallized surface according to item 1.