JPH11269302A - Filler for improving thermal conductivity of resin product and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a filler useful for improving thermal conductivity of a resin product such as a semiconductor sealing resin. SOLUTION: This filler for improving thermal conductivity of a resin product comprises AlN spherical sintered body having 10-200 μm average particle diameter. The filler is obtained by blending AlN powder with a molding adjuvant, wet-blending the obtained mixture, granulating the wet-blended materials by a spray drier to provide granules, mixing BN powder with the obtained granules and firing the obtained mixture in nitrogen stream at >=1,500 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler for improving the thermal conductivity of a resin product such as a resin for a semiconductor encapsulation resin, a heat radiation sheet for heat radiation bonding, and a heat radiation substrate.

[0002]

2. Description of the Related Art Fused silica has been mainly used as a conventional filler for semiconductor encapsulation resins.
This was inferior in thermal conductivity, and could not achieve the desired effect. However, in recent years, due to the increase in the density of heat-generating electronic components, demands for heat radiation of these components have been increasing.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a filler which meets such a demand and which is useful for improving the thermal conductivity of a resin product such as a semiconductor sealing resin.

[0004]

The present invention focuses on the characteristics of AlN (aluminum nitride), particularly on the thermal conductivity, and provides a method for solving the above-mentioned problem by forming it into a spherical sintered body. I found it.

That is, in the present invention, the average particle size is 10 to 20.
The AlN spherical sintered body of 0 μm is used as a filler for resin products.

[0006] The base material of each electronic component that requires heat dissipation, for example, a heat dissipation sheet, has a higher thermal conductivity as the thermal conductivity of the filler is higher and the amount of the filler added is greater. The properties required as a filler include high thermal conductivity, good fluidity, and the ability to be contained in a large amount in a resin or the like.AlN sintered bodies of the present invention have high thermal conductivity. Since it has and is spherical, it is rich in fluidity and can be added to other resins in a large amount. As a result, all of the above requirements are satisfied. The average particle size of the AlN spherical sintered body is 10 to 20.
It may be about 0 μm, but in order to improve the packing density, it is particularly preferably about 50 to 150 μm. If the particle size is too large, the fluidity is reduced, and it is difficult to disperse the resin at a high content.

[0007] Such an AlN spherical sintered body is obtained by mixing a molding aid with AlN powder, wet-mixing, granulating using a spray drier, and mixing BN powder with the obtained granule, and subjecting the mixture to a nitrogen stream. And by firing at a high temperature of 1500 ° C. or more.

For example, a molding aid is added to AlN powder alone or a mixture of a sintering aid (Y ₂ O ₃ , CaO, etc.) and wet-mixed, and the mixture is formed by a spray drier. BN is added to 100 parts by weight of the obtained granulated powder.
(Boron nitride) 1 to 30 parts by weight of powder may be mixed and fired at 1700 ° C. or higher and lower than 1950 ° C. in a nitrogen stream. As a molding aid, a resin such as a methylcellulose-based resin or polyvinyl butyral is added to the AlN powder in an amount of 1 to 10.
It is preferable to add about 10% by weight.

[0009] The reason for adding BN is to prevent the AlN granulated powder from burning together during firing. BN is useful because it is stable at high temperatures and has no reactivity with AlN. The particle size distribution of the granulated powder can be controlled by changing the granulation conditions.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to Examples. In the Examples, "parts" and "%" indicate "parts by weight" and "% by weight" unless otherwise specified. Example 1 Average particle size 0.8 μm, oxygen content 0.6
%, 97 parts of 98% pure AlN powder, average particle size 1.0μ
m ₂ of Y ₂ O ₃ powder were added. This mixed powder 100
55 parts of ethanol, 1 part of a dispersant and 1.5 parts of polyvinyl butyral were added to the mixture, and mixed with a pot mill for 24 hours. Next, the slurry thus prepared was granulated and dried with a rotating disk type spray drier. Thereafter, 100 parts of the AlN granules are mixed with 10 parts of BN, and the mixture is filled in an AlN crucible, and is placed in a nitrogen stream at normal pressure for 1800 minutes.
Calcination was performed at 4 ° C. for 4 hours. This baked product is ultrasonically dispersed in ethanol, and then filtered to separate and remove BN, and then dried,
An AlN spherical sintered body was obtained. This AlN spherical sintered body has an average particle size of 103 μm and a thermal conductivity of 170 to 220 W.
/ Mk. An example in which this spherical sintered body is blended as a filler with a novolak epoxy resin is shown in the following table in comparison with a conventional example (using fused silica as a filler).

[0011]

[Table 1]

Example 2 100 parts of AlN powder having an average particle diameter of 0.8 μm, an oxygen content of 0.6% and a purity of 98% were mixed with 50 parts of ethanol, 1 part of a dispersant, and 1.5 parts of polyvinyl butyral.
Was added and mixed on a pot mill for 24 hours.

After mixing, the slurry is granulated with a rotary disk type spray drier, dried, and 100 parts of the obtained AlN granules are mixed with 10 times of BN, filled into an AlN crucible, and filled with nitrogen under normal pressure. It was baked at 1800 ° C. for 4 hours in an air stream.
The fired product was ultrasonically dispersed in ethanol, filtered to remove BN, and dried to obtain an AlN spherical sintered body. The average particle size of this AlN spherical sintered body is 88 μm
And the thermal conductivity was 50 to 100 W / mk. An example in which this spherical sintered body is blended as a filler with biphenyl epoxy resin is shown in the following table in comparison with a conventional example (using fused silica as a filler).

[0014]

[Table 2]

[0015]

The filler of the present invention, which is a spherical sintered body, can be filled in a resin product at a high density and has a very high thermal conductivity, so that the thermal conductivity of the resin product can be significantly improved. And also significantly improves the heat dissipation.

Claims (2)

[Claims] 1. Al having an average particle size of 10 to 200 μm.
A filler for improving thermal conductivity of a resin product, comprising a N-sphere sintered body. 2. An AlN powder is mixed with a molding aid, and after wet mixing, BN powder is mixed with granules obtained by granulation using a spray drier, and the mixture is mixed in a nitrogen stream at 1500
A method for producing a filler for improving thermal conductivity of a resin product, wherein the filler is fired at a high temperature of not less than ° C.