JPH01263131A - Silica for filling sealing resin - 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 [Industrial Application Field] The present invention relates to silica for filling an IC sealing resin, and particularly to silica having excellent filling properties and fluidity for thermosetting resins.
This invention relates to silica for C sealant filler.

[Prior Art] Conventionally, crushed or spherical silica with an average particle size of 7 to 30 μs has been generally used as this type of silica for filling the sealing resin.

However, when crushed or spherical silica having such a particle size is filled into a resin as a filler,
Approximately 20% by volume of interparticle voids of 3 or less size exist, and the filler filling rate in this resin is inevitably limited to 80% by volume or less. Because the compound of resin and silica does not have good fluidity, it is not possible to add silica at a high addition rate. It becomes difficult to improve sexual performance.

In addition, 20 to 97% by weight of fused silica powder with an average particle diameter of 1 p or more and 80 to 97% by weight of spherical silicic powder with an average particle diameter of 10 to 800 mμ
It has also been proposed to mix 3% of the amount
-204, No. 633), specifically, as an example thereof, fused quartz powder with an average particle size of 25p and an average particle size of 20mμ
It is being used in combination with Aerosil (spherical silicic acid powder).

However, even in this method, the average particle size is 20Tr.
Since the particle size of Lμ Aerosil is small, the influence of the Noanderthal force acting between these fine particles becomes large, which inevitably reduces the filling property. Because of the manufacturing method, particles with a particle size of 100 mμ or more cannot be obtained.

By the way, when using crushed silica as the filling silica, it is possible to obtain a certain amount of filling ft by appropriately mixing silica with different degrees of pulverization and adjusting the particle size, but even in this case, the filling ft can be sufficiently satisfied. It wasn't something.

[Problem to be solved by the invention J] As a result of extensive research in view of the above, the present inventors have selected silica having a specific particle size distribution and particle shape as the silica for filling with Murakami resin. It was discovered that the filling properties and fluidity in resins, especially thermosetting resins, can be significantly improved by this method, and the present invention was achieved based on this finding.

Therefore, an object of the present invention is to provide a silica for sealing that has filling properties and fluidity superior to sealing resins.

[Means for Solving the Problems] That is, the present invention provides crushed or spherical coarse-grained silica having an average particle diameter of 7 to 30 mm, and an average particle diameter d of 0.1.
Monodisperse spherical fine grain silica in the range of ~31U
The seal consisting of 0% pits) is 1 fat-filling silica.

The coarse silica used in the present invention may be pulverized silica or spherical silica, but its average particle diameter is 7 to 30, preferably 8 to 1.
If the average particle size is smaller than 7mm, the fluidity of the resin compound will decrease rapidly;
Beyond the cape, this coarse silica forms the surface of the object to be sealed (!!-
It is easily damaged, and especially in the case of IC sealing, the fine pattern of the IC can be damaged by the corners of the silica particles, which may cause the wire of the honding wire to come loose or open. In the case of pulverized silica, it is possible to achieve a filling property to the extent that the particle size is adjusted as described above, but in the case of spherical silica, such particle size adjustment is difficult. effect will be more effectively demonstrated.

The monodisperse spherical fine particle silica to be blended with such coarse particle silica having an average particle diameter D (7 to 30/ffi>) has an average particle diameter d in the range of 0.1 to 3 μs, preferably 0.2 to 111R. The blending ratio is 5 to 40% by weight, preferably 10 to 30% by weight of the total.If the average particle diameter d is smaller than 0.1 cape, there is a tendency for fine particles to agglomerate. On the other hand, if the average particle diameter d is larger than 3 μs, the voids become larger than the voids formed by the coarse silica, and the void filling effect is impaired. If the blending ratio is less than 40% by weight, the amount is insufficient to fill the voids in the coarse silica, and on the other hand, if the blending ratio exceeds 40% by weight, there will be a problem that the amount will be more than necessary compared to the voids in the coarse silica.

Furthermore, in the present invention, in order to achieve even higher filling properties and higher fluidity, the difference between the average particle size of the coarse silica and the average particle size d of the fine silica is 0.02D<d< 0.
1D relationship, more preferably 0.03D<d<0.07
It is preferable that a relationship of 0 exists. By using coarse silica and fine silica, which have such a relationship, and selecting their blending ratio within the above range, the voids formed when filling the coarse silica can be filled with monodispersed spherical fine silica. silica can be filled in the encapsulating resin, preferably a thermosetting resin, as a filler for an IC encapsulating material at a high density, and the resulting compound can have high fluidity. I can do it.

In addition, it may be possible to use irregularly shaped crushed fine silica for the purpose of filling voids, but its filling properties are inferior to monodispersed spherical fine silica, and even with the same spherical fine silica, silica with a wide distribution may be used. Although it is conceivable to do so, it becomes difficult to determine the optimum blending ratio with coarse silica due to the particle size control 5.

As a method for producing such monodispersed spherical fine silica used in the present invention, for example, silicon alcoholate is hydrolyzed in an alcohol-water annealed solution,
A method of manufacturing by drying and firing the obtained spherical silica particles (Tober et al., J.

Co11oid Interface Sci,,Vo
l, 26. p62 (1968)), and by this method, an average particle size of 0.1 to 3 μm and a specific surface area of 30 rrt/
Monodispersed spherical fine silica with a size of q or less! j can be reported. The monodispersed spherical fine-grained silica obtained in this way still has a porosity of about 25% even if it is hexagonally close-packed, and high packing properties cannot be obtained, but it cannot be obtained with coarse-grained silica. Excellent filling properties and fluidity can be obtained by blending fine silica in an appropriate proportion, that is, 5 to 40 ant% of coarse silica.

In addition, when mixing the above-mentioned coarse-grained silica and monodispersed spherical fine-grained silica, a ball mill or a Henschelmigisser is suitable; Requires the use of a brass stick ball.

The filling silica of the present invention can be blended into various resins such as epoxy resins and polyimide resins as fillers for IC encapsulants. As with silica, a method of kneading using means such as heated rolls can be employed.

[Examples] The present invention will be specifically described below based on Examples and Comparative Examples.

Examples 1 to 6 and Comparative Examples 1 and 2 Orthocresol nophorac epoxy resin with an epoxy equivalent of 200 (epoxy resin A > 80 parts by weight, brominated phenol nophorac epoxy resin (epoxy resin B) 20 parts by weight, phenol equivalent of 105 Phenol novolak resin (curing agent>50 parts by weight, 2-methylimidazole (hardening accelerator) 0.5 parts by weight, carnauba wax (mold release agent)
1 part by weight, 4 parts by weight of antimony trioxide (flame retardant), γ-
1 part of glycidoxypropyltrimethoxysilane (coupling agent) and 1 part of carbon black (coloring agent), crushed silica (Silica A) with an average particle size of 16 μm, crushed silica (Silica B) with an average particle size of 7 μm. ), average particle size 1.0
Monodisperse spherical silica (Silica C) of μm and average particle size of 0.
Two types of monodispersed spherical silica (Silica D) were blended in the proportions shown in Table 1, kneaded with heated rolls, cooled, and crushed to give 1 q of the epoxy resin compositions of each example and comparative example. .

The spiral flow and gel time of the epoxy resin compositions of these Examples and Comparative Examples were measured.
The filling properties of silica into fat and the fluidity of the obtained epoxy resin composition were evaluated. The results are shown in Table '1.

Incidentally, the spiral flow was measured according to the 1-1-66 method, and the gel time was measured at 175°C according to the Tsuki SK-6911 method.

Examples 1 and 3 are cases where coarse silica with an average particle size of 16/711+ is blended with monodispersed spherical fine silica with an average particle size of 1 μm, and the spiral flow is longer than in Comparative Example 1, but in Example 2, the blend Because the monodispersed spherical fine silica particles are too small, the effect is low.

Further, in Example 4, monodispersed spherical fine silica with an average particle size of 1 μm is blended with coarse silica with an average particle size of 7 μm, and the fine silica particles are too large to have little effect. In Examples 5 and 6, coarse silica with the same average particle size of 7 μm was mixed with an average particle size of 0.
Although the monodispersed spherical fine silica of 3 Misaki is blended, the fluidity is improved compared to Comparative Example 2. The improvement in fluidity is due to the improvement in the filling properties of silica.

In addition, various combinations of coarse silica, ie, silica A and silica B, and monodispersed spherical fine silica, ie, silica C and silica D, were blended to see if the blend had an effect on improving fluidity. The results are shown in Table 2. In Table 2, cases where there is a flowability improvement effect due to blending are expressed as ◯, and cases where there is little are expressed as △.

[Effect of the invention 1] The silica for filling a sealing resin of the present invention has a remarkable improvement in the filling property into the sealing resin and the fluidity during molding of the sealant prepared using the silica (potassium composition). and by this unfilled,
It is possible to solve moldability problems such as void generation, and it is also possible to reduce thermal expansion coefficient and water absorption due to high density packing of silica, and solve problems of thermal stress and moisture.

Applicant: Nippon Steel Chemical Co., Ltd.

Claims (2)

[Claims] (1) 5 to 40% by weight of the total monodispersed spherical fine silica with an average particle diameter d of 0.1 to 3 μm is mixed with crushed or spherical coarse silica with an average particle diameter D of 7 to 30 μm. A silica for filling a sealing resin characterized by: (2) The silica for sealing resin filling according to claim 1, wherein there is a relationship of 0.02D<d<0.1D between the average particle diameter D of the coarse silica and the average particle diameter d of the monodispersed spherical fine silica. .