JPH0442860A - Black aluminum nitride sintered product - Google Patents

Abstract

PURPOSE:To provide a black Al sintered product having excellent strength, density, thermal conductivity and light-shielding property by adding a rare earth element compound, W (compound) or/and Mo (compound) and Zr (compound) to Al powder, and subsequently calcining the mixture. CONSTITUTION:(A) Aluminum nitride powder is mixed with (B) a rare earth element compound (e.g. Y2O3), (C) at least one selected from tungsten, tungsten compounds (e.g. WO3), molybdenum and molybdenum compounds (e.g. MoO3) and (D) at least one selected from zirconium and zirconium compounds (e.g. ZrO2). The mixture powder is sintered to prepare a black aluminium nitride sintered product which is free from irregular sintering, irregular color, etc., has black color and is suitably used for insulated substrates, semiconductor device package materials, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention has high strength, high density, high thermal conductivity, and excellent light shielding properties, and is suitable as an insulating substrate, a heat sink material, a semiconductor package material, etc. The present invention relates to the black aluminum nitride sintered body used.

[Problems to be solved by conventional techniques and inventions] In recent years,
As LSIs become more highly integrated and densely packed, the amount of heat generated per package is increasing. For this reason, the heat dissipation properties of substrate materials are considered important, and aluminum nitride substrates, which have excellent thermal conductivity and can ensure good heat dissipation properties, are attracting attention as an alternative to conventional alumina substrates.

Aluminum nitride sintered bodies have high thermal conductivity, high strength, and excellent electrical properties, and have a thermal expansion coefficient close to that of silicon, allowing good bonding with silicon, making them ideal for use in semiconductor devices, etc. Although aluminum nitride is suitable as a material for a flexible substrate, it is difficult to obtain a dense sintered body because it has strong covalent bonding properties and is a de-sintered material.

Therefore, in order to obtain a dense nitrogen-aluminum sintered body, a method of adding a sintering aid such as a rare earth oxide or a method of sintering aluminum nitride using a hot press method has been proposed. However, the sintered bodies obtained by these methods have high density.

It has the disadvantage of poor thermal conductivity.

Further, when an aluminum nitride sintered body is used as a packaging material for a semiconductor device, etc., it is required to have good light-shielding properties in order to prevent harmful effects such as soft errors on the IC memory due to the transmission of ultraviolet rays.

Conventionally, a method of adding tungsten oxide or molybdenum oxide to aluminum nitride powder has been known as a method of obtaining a black aluminum nitride sintered body having light-shielding properties.

However, the sintered body obtained by this method has poor thermal conductivity. A method of adding tungsten oxide or molybdenum oxide together with a rare earth compound has also been proposed (Japanese Patent Application Laid-Open No. 162576/1983). However, in this case, although the thermal conductivity is relatively improved, the resulting sintered body is inferior in strength.

As described above, the current situation is that aluminum nitride sintered bodies having sufficient strength, density, thermal conductivity, and light-shielding properties to be used as insulating substrates, heat sink materials, packaging materials for semiconductor devices, etc. have not been obtained.

The present invention was made in view of the above circumstances, has high strength, high density, high thermal conductivity, and excellent light shielding properties, and can be suitably used as an insulating substrate, a heat sink material, a packaging material for semiconductor devices, etc. The purpose is to provide a black aluminum nitride sintered body.

[Means and effects for solving the problem] As a result of intensive studies to achieve the above object, the present inventors added tungsten and tungsten compounds, molybdenum and molybdenum together with rare earth compounds as additives to aluminum nitride powder. By firing one or more selected compounds and one or more selected from zirconium and zirconium compounds, high strength, high density, and high thermal conductivity, for example, 180 W/m- can be obtained. The present invention was completed based on the discovery that a black aluminum nitride sintered body having the above thermal conductivity can be obtained.

Therefore, the present invention provides aluminum nitride powder with one or two selected from rare earth compounds, tungsten and tungsten compounds, and molybdenum and molybdenum compounds.
Provided is a black aluminum nitride sintered body characterized by adding one or more types selected from zirconium and zirconium compounds and firing the mixture.

The present invention will be explained in more detail below.

In the present invention, examples of the rare earth compound added to the aluminum nitride powder include oxides, borides, carbides, halogen compounds, and nitrides of rare earth elements such as Sc, Y, La, and Dy+Ce, but in particular, YzOi, I ))'
Z○1 etc. are preferably used. The amount of this rare earth compound added is 0.01 to IS% (weight %, the same below) based on aluminum nitride (the same applies below) in terms of the weight of the rare earth element.
In particular, it is preferably 0.1 to 10%. If this amount is less than 0.01% or more than 15%, it may not be sufficiently densified and the thermal conductivity may decrease.

The black aluminum nitride sintered body of the present invention is produced by adding tungsten (W) to aluminum nitride powder together with the above rare earth compound.
) and W compounds, and one or more selected from molybdenum (MO) and MO compounds and zirconium (Z
Zr) and one or more selected from Zr compounds are added and fired, and compounds of these metals include oxides, borides, carbides, halides, nitrides, etc. .

The blending amounts of these additives are W and/or M) and Zr.
0.01 to 15%, especially 0°1 to 15% in terms of weight.
It is preferable to set the amount to 10%; if the blending amount is less than 0.01%, color unevenness may occur in the sintered body;
%, the growth of crystal grains becomes noticeable, which may result in a decrease in density, and may further result in a decrease in thermal conductivity.

Here, W or a W compound and Zr or a Zr compound are used to provide a uniform black color without uneven baking or uneven coloring, and also to provide Zr.
The r or Zr compound each contributes to dramatically improving the strength of the sintered body. Furthermore, when W and/or MO and Zr are used as metal powders, mechanical strength is particularly improved, and furthermore, it is a sintered material that has excellent properties as a structural material, etc. with excellent thermal properties and good leakage with metal. Solids can be obtained, and when these metals are used as oxides, the volume resistivity value increases dramatically, and excellent electrical I1 is obtained.
1! It is possible to obtain a sintered body that has excellent characteristics as an insulating substrate material for hybrid ICs, etc., which exhibits high heat resistance and excellent thermal characteristics. Therefore, by appropriately adjusting the types and amounts of these additives, it is possible to impart properties to the sintered body depending on the intended use.

Note that the raw material aluminum nitride powder is not particularly limited, but it is preferable to use one having an average particle size of 5 μm or less, particularly 2 μm or less.

Moreover, the above-mentioned rare earth element compounds, W, and Mo.

The average particle size of Zr and its compounds is preferably as fine as 10 μm or less, particularly about 5 μm.

The black aluminum nitride sintered body of the present invention is obtained by adding these additives and the above-mentioned rare earth compounds to aluminum nitride powder and firing the mixture. In this case, the firing temperature was 16oO
It is preferable to set it as -2100 degreeC, especially 1650-2000 degreeC, and sintering may not progress sufficiently at less than 1600 degreeC.

On the other hand, if the temperature exceeds 2100°C, decomposition of aluminum nitride itself may occur. Further, the atmosphere during firing can be a nitrogen atmosphere.

〔Effect of the invention〕

The black aluminum nitride sintered body of the present invention has high strength, high density, and high thermal conductivity, exhibits a uniform black color without uneven firing or coloring, and has excellent light shielding properties, and can be used as an insulating substrate. It is suitably used as a heat sink material, a package material for semiconductor devices, etc.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

[Example, comparative example]

The first powder was added to aluminum nitride powder with an average particle size of 1.40 μm.
The sintering aids shown in the table were added and mixed well, and the mixture was sintered under the conditions shown in the table under a nitrogen gas atmosphere to obtain a sintered body of aluminum nitride.

Regarding the obtained sintered body, its appearance, density, bending strength,
The volume resistivity and thermal conductivity were investigated.

The results are also listed in Table 1.

Note that the amounts of each sintering aid in Table 1 are all weight %.

As is clear from the results shown in Table 1, the aluminum nitride sintered body of the present invention exhibits excellent thermal conductivity, is black and has excellent light shielding properties, is dense and has high density, and has excellent mechanical strength and It has excellent electrical properties.

Applicant: Shin-Etsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A rare earth compound, one or more selected from tungsten and tungsten compounds, molybdenum and molybdenum compounds, and one or more selected from zirconium and zirconium compounds are added to aluminum nitride powder, and fired. A black aluminum nitride sintered body characterized by: