JP2000319633A - Silica filter for epoxy resin sealing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silica filler which can give a sealing material having improved flowability and realizing reduction in burr formation, etc., which filler comprises spherical amorphous silica microparticles having a mean particle diameter in a specified range. SOLUTION: This filler comprises spherical amorphous silica microparticles having a mean particle diameter of 8-65 nm. Desirably, the filler comprises spherical amorphous silica microparticles (A) having a mean particle diameter of 8-65 nm and silica particles (B) having a mean particle diameter of 0.5-40 μm. Desirably, the mixing ratio of component A to component B is such that (A)/[(A)+(B)]=0.01-0.5 by mole. Amorphous silica microparticles A are properly spherical amorphous microparticles produced by a DC arc plasma process and produced by oxidizing silicon in a plasma state and cooling the product and has a specific surface area in a range of 45-300 m2/g (as measured by the BET method).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silica-based filler for an epoxy resin-based sealing material used for a surface-mounted resin-sealed semiconductor device of a semiconductor chip or a thin package.

[0002]

2. Description of the Related Art Conventionally, a resin-encapsulated semiconductor device which has been developed to be called rice in the industry has a glass transition point Tg after molding and curing of 150 to 180 ° C., and natural crystalline silica particles as an inorganic filler. Alternatively, an epoxy resin-based sealing material containing 50 to 85% by weight of fused silica particles or a mixture of these fillers is used. The compounding ratio of the inorganic filler is 5
If the amount is less than 0% by weight, the effect of reducing the coefficient of linear expansion is small.
If the content is more than 10% by weight, there is a problem that the viscosity of the resin composition increases and the fluidity decreases. Further, silica fine particles having a large specific surface area such as Aerosil obtained by a high-temperature hydrolysis method (gas phase method) of silicon tetrachloride in an oxyhydrogen flame have a large specific surface area such as 100 to 300 m ² / g. Several percent is added as a deburring measure. However, the use of silica fine particles having a large specific surface area according to the above-mentioned production method has a drawback that the fluidity is significantly reduced.

[0003] In particular, since semiconductor packages tend to be thinner in order to cope with higher packaging densities, there is a need for a oxy-resin-based sealing material that has a high fluidity of the sealing material and less burrs. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made as a result of intensive studies to solve the conventional problems.
It has been found that the use of amorphous silica fine particles of up to 65 nm improves the fluidity of the sealing material and provides an epoxy resin-based sealing material that can reduce burrs and the like.

[0005]

That is, the present invention provides (A) an amorphous silica fine particle having an average particle size of 8 to 65 nm in a silica filler used for an epoxy resin sealing material. Characteristic silica filler for epoxy resin-based sealing materials.

Further, the present invention relates to a silica-based filler used for an epoxy resin-based sealing material, wherein (A) amorphous silica fine particles having an average particle size of 8 to 65 nm and (B) average particle size of 0.5 to 65 nm. A silica-based filler for an epoxy resin-based sealing material, characterized by using silica particles of 40 μm.

The above-mentioned (A) amorphous silica fine particles having an average particle diameter of 8 to 65 nm are produced by a DC arc plasma method, and are spheric non-spherical particles produced by oxidizing and cooling silicon in a plasma state. A crystalline fine particle having a specific surface area (BET method) of 45 to 300 m ² / g.

In the DC arc plasma method described above, a silicon material is used as a consumed anode electrode, a plasma flame of argon gas is generated from a cathode electrode, the silicon material is heated and evaporated, and silicon in the plasma state is oxidized and cooled. In this method, spherical amorphous silica fine particles having an average particle diameter in the range of 8 to 65 nm can be manufactured. If the average particle diameter is less than 8 nm, the production efficiency is deteriorated, and if the average particle diameter is more than 65 nm, the possibility of forming coarse particles is increased, which is not preferable. The spherical amorphous silica fine particles produced by this method have a feature that dispersion treatment is easy because they are extremely loosely aggregated. The measurement of the average particle diameter was calculated by a specific surface area method.

The (B) silica particles having an average particle size of 0.5 to 40 μm are fillers such as fused silica, crystalline silica, spherical silica, and pulverized silica which have been conventionally used. Spherical silica particles obtained by pulverizing silica with a ball mill or the like and then melting and spheroidizing in a flame melting furnace with oxygen and flammable gas, and spherical silica particles obtained by the deflagration method have excellent fluidity. preferable.

The mixing ratio of the above-mentioned silica-based filler in the entire composition of the epoxy resin-based sealing material is 60 to 95% by weight.
It is preferable that the blending ratio of the spherical amorphous silica fine particles of the component (A) and the silica particles of the component (B) is (A) / [(A) + (B)] = 0.01 by weight ratio. The range of 0.5 to 0.5 is preferable. When the compounding ratio is less than 0.01, the effect of improving the fluidity is small, and even when the compounding ratio exceeds 0.5, the effect of improving the spherical amorphous silica fine particles of the component (A) is expensive. Tend to be smaller.

The epoxy resin used in the present invention includes bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl epoxy resin, resorcinol glycidyl ether epoxy resin and the like. it can.
Further, examples of the curing agent include phenolic compounds such as phenol novolak resins and phenol aralkyl resins, acid anhydrides such as pyromellitic anhydride and benzophenone anhydride, and amine compounds.

Further, various known and commonly used additives such as a flame retardant, a coloring agent, a release agent, a low stress additive, a curing accelerator, and a coupling agent may be appropriately added to the epoxy resin-based sealing material as needed. It can also be blended.

Next, in order to adjust the sealing material from the above-described components, an epoxy resin, a curing agent, (A) spherical amorphous silica fine particles, (B) silica particles, and, if necessary, curing acceleration After thoroughly mixing the ingredients, additives, etc., melt kneading,
After being cooled and pulverized, it is further molded into a tablet by a molding machine.

[0014]

According to the present invention, the (A) spherical amorphous silica fine particles having an average particle diameter of 8 to 65 nm used for the epoxy resin-based sealing material impart thixotropic properties to the epoxy resin-based sealing material. This has the effect of improving the fluidity and realizing the reduction of burrs and the like.

[0015]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Examples 1-4, Comparative Examples 1-2 Epoxy resin ("EOCN-102", manufactured by Nippon Kayaku Co., Ltd.)
67 parts by weight, curing agent (manufactured by Dainippon Ink and Chemicals, "T
D-2131 ") 33 parts by weight and a silica-based filler in the amount (parts by weight) shown in Table 1, 2 parts by weight of a silane-based coupling agent, 0.5 parts by weight of wax, 0.5 parts by weight of carbon black, The composition containing 1 part by weight of a curing accelerator was uniformly melt-kneaded with two rolls, cooled and pulverized to obtain six types of thermosetting resin compositions. These compositions were used in a mold conforming to the Spiral Flow EMM standard,
The spiral flow value was measured under the conditions of kg / cm ² , a temperature of 175 ° C. and 120 seconds.

[0017]

[Table 1]

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Claims (6)

[Claims] 1. An epoxy resin-based encapsulation, wherein (A) spherical amorphous silica fine particles having an average particle diameter of 8 to 65 nm are used as a silica-based filler used in an epoxy resin-based encapsulation material. Silica-based filler for materials. 2. A silica-based filler used in an epoxy resin-based encapsulant, wherein (A) spherical amorphous silica fine particles having an average particle size of 8 to 65 nm and (B) average particle size of 0.5 to 4
A silica-based filler for an epoxy resin-based sealing material, characterized by using silica particles of 0 μm. 3. The epoxy resin-based encapsulation according to claim 1, wherein the mixing ratio of the silica-based filler in the entire epoxy resin-based encapsulation material composition is 60 to 95% by weight. Silica-based filler for materials. 4. A mixing ratio of the spherical amorphous silica fine particles of the component (A) and the silica particles of the component (B) in a weight ratio of (A)
The silica-based filler for an epoxy resin-based sealing material according to claim 2 or 3, wherein /[(A)+(B)]=0.01 to 0.5. 5. The epoxy resin sealing material according to claim 1, wherein the spherical amorphous silica fine particles of the component (A) are produced by a DC arc plasma method. Silica-based filler. 6. An epoxy resin-based sealing material using the silica-based filler for an epoxy resin-based sealing material according to any one of claims 1 to 5.