JPH03210A - Manufacture of epoxy resin forming material - Google Patents

Abstract

PURPOSE:To make it possible to manufacture epoxy resin forming material, which highly contains inorganic filler, has low viscosity and is excellent in formability with small generation of thin fin by a method wherein resin composition is again heated, melted and kneaded after the subsequent addition of hardening assistant and, after that, cooled and ground. CONSTITUTION:Resin composition, which consists of epoxy resin (a), phenol- novolak setting agent (b) and inorganic filler, is heated, melted and kneaded and, after that, cooled and ground into particulates. Hardening assistant is dispersed in the resultant particulates and again heated, melted and kneaded and finally cooled and ground. From five to ten pts.wt. of phenol-novolak setting agent (b) is used with respect to 10-20 pts.wt. of the epoxy resin (a). As the inorganic filler, 400-1000 pts.wt. of powder singly such as crystal silica, fused silica or the like or their combination is used with respect to 100 pts.wt. of the sum of the components (a) and (b). As the setting assistant, imidazoles, tertiary amine or the like is preferable and 0.05-5 pts.wt. of the hardening assistant is used with respect to 100 pts.wt. of the sum of the components (a) and (b). Further, the particulate is preferably a finely divided particle having a particle diameter below 100 mesh.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an epoxy resin molding material useful for semiconductor encapsulation used for the purpose of protecting semiconductor elements.

[Conventional technology]

In recent years, in the semiconductor field, demands for higher integration, higher functionality, higher speed, and higher output have been increasing year by year.

Accordingly, there are demands for encapsulating materials for encapsulating semiconductor devices to have not only moisture resistance but also low stress and high thermal conductivity. For this reason, there is an increasing need to increase the amount of inorganic filler. However, it has not been possible to ensure low viscosity of the molding material when the inorganic filler is highly filled in order to achieve low stress and high thermal conductivity. Therefore, due to the high viscosity of the molding material, wires within the semiconductor device 1 may be deformed or cut, and furthermore, there may be problems such as unfilling or voids in the semiconductor device as a molded product, which is harmful to moisture resistance. . In addition, in order to form a molding material by blending each component at once and heating, melting, and cross-wiring, the wetting of the resin and inorganic filler cannot be achieved sufficiently in order to achieve an appropriate degree of curing of the resin. There was a problem in that a lot of thin flakes were generated around the product and it was very difficult to remove them.

(Problems to be Solved by the Invention) To provide a method for manufacturing an epoxy resin molding material that is highly filled with inorganic fillers, has low viscosity, has excellent moldability, and has less flakiness generated around molded products. be.

[Means to solve the problem]

In order to solve the problem, the present inventors have discovered that by thoroughly kneading and wetting the inorganic filler and resin without allowing the resin to harden much before molding, the viscosity of the molding material can be reduced. Furthermore, it was discovered that the resin and the inorganic filler exhibit the same behavior, thereby reducing thin flakes, leading to the present invention. That is, the present invention provides (a) an epoxy resin, (
B) After heating, melting and kneading a resin composition consisting of a phenol novolak curing agent, (c) and an inorganic filler, (d) curing aid is dispersed in the cooled and pulverized powder, and heated again. An object of the present invention is to provide a method for producing an epoxy resin molding material, which comprises melting, kneading, cooling, and pulverizing.

The invention described above will be explained below. First, as the epoxy resin (a) of the present invention, any known resin known to have good properties such as moisture resistance and heat resistance can be used as appropriate. Examples of such epoxy resins include novolak epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, alicyclic epoxy resins, and halogenated epoxy resins.

Preferred examples of the phenol novolak curing agent (b) include phenol novolak type resins having two or more phenolic hydroxyl groups in one molecule, including conventionally used phenol novolak resins and cresol novolak resins. , xylenol novolac resin, etc., to 10 to 20 parts by weight of epoxy resin.
It can be used in a range of 10 parts by weight.

As the inorganic filler (c), commonly used powders such as crystalline silica, fused silica, alumina, silicon nitride, titanium oxide, carbonate, etc. can be used alone or,
In combination, 400 to 1000 parts by weight can be used based on 100 parts by weight of the total amount of components (a) and (b).

In particular, highly pure crystalline silica, fused silica, alumina, and silicon nitride are preferred, and the particle size of these inorganic fillers is preferably less than 100 μm because they do not clog the gate of the mold. In order to improve wetting between the inorganic filler and the resin, these inorganic fillers are coated with a coupling agent,
For example, it can also be treated with epoxysilane, aminosilane, etc.

As the curing aid (2), imidazoles, tertiary amines, etc. are desirable, and the amount used is 0.05 to 5 parts by weight per 100 parts by weight of the total amount of components (a) and (b). I can do it. Since the curing aid is added later, it is preferably solid, and the particle size is preferably less than 100 mesh in order to prevent clogging of the mold gate and to ensure uniform dispersion.

In addition, commonly used mold release agents include carnauba wax, stearic acid, and metal salts of stearic acid, and dyes and pigments include carbon black, titanium oxide, and black organic dyes of azo metal-containing compounds. Antimony dioxide, aluminum hydroxide, etc. are used as flame retardants as necessary.

When blending the above ingredients to make a molding material, heating, melting, and kneading can be performed using heated rolls or a kneader, and dispersion, cooling, and pulverization can also be performed using ordinary equipment used in the production of molding materials. can be used. Using these devices, component (a) epoxy resin, component (b) phenoltuborac curing agent, component (c) inorganic filler and mold release agent, dyes and pigments, flame retardants, etc. The powder is blended as necessary and passed through a mixing/dispersing machine.
It is heated, melted, and kneaded using hot rolls to form a sheet, hardened using a cooling machine, and made into powder using a pulverizer.

The hardening aid of component (d) is added to this powder and granules afterward, and the powder and granules are homogeneously dispersed using a mixing and dispersing machine.Then, the powder and granules are again heated, melted, and kneaded with hot rolls to form a sheet, and then solidified with a cooling machine. (death,
The epoxy resin molding material is manufactured in the form of powder using a pulverizer.

〔Example〕

Example 1 Orthocresol novolak epoxy resin (epoxy equivalent: 220, softening point: 64°C) was used as an epoxy resin at 14
Part by weight, phenol novolak resin (OH
7 parts by weight of N110, softening point 80''
．． 5 parts by weight, 0.4 parts by weight of carnauba wax as a mold release agent, and 0.4 parts by weight of carbon black as a pigment.After uniformly dispersing these components, they were heated, melted, and kneaded with a hot roll at 100'C. The process was repeated 20 times, then cooled and pulverized to form a powder, and as a hardening agent, 2-methylimidazole with a particle size of less than 100 mesh was added to the powder.
．． Add 1 part by weight, uniformly disperse and mix, and add 100% by weight again.
The mixture was thoroughly heated, melted, and kneaded 5 times using a hot roll of 'C', and then cooled and crushed to form a powder into an epoxy resin molding material.

Example 2 The particle size of the hardening aid 2 methylimidazole in Example 1 was changed to 10
Except for using 2-methylimidazole with a mesh size of 0 or more,
An epoxy resin molding material was prepared in exactly the same manner as in Example 1.

Comparative Example 1 The ingredients were the same as in Example 1' except for the amount of curing aid, and the components except for the curing aid were first uniformly dispersed, and then heating, melting, and cross-wiring were repeated 20 times with a heated roll at 100°C. After cooling and pulverizing the thoroughly processed material, 0.15 parts by weight of 2-methylimidazole with a particle size of less than 100 mesh is added as a hardening agent, and the mixture is uniformly dispersed and mixed to form epoxy resin. It was used as a material.

Comparative Example 2 With the same component composition as in Example 1, the hardening aid 2-methylimidazole was uniformly dispersed from the beginning together with other components, and then 1
The mixture was heated, melted, and kneaded six times using a hot roll at 00°C, then cooled and pulverized to obtain a granular epoxy resin molding material. In addition, if the same compounded product is heated, melted, and kneaded 12 times with a heated roll at 100°C, then cooled and crushed to form a powdered epoxy resin molding material, it is not possible to mold it. It had hardened to the point where it could not be done.

Using each of the epoxy resin molding materials obtained above, the melt viscosity was measured using a Shimadzu Koka type flow tester (nozzle shape φ1 m*, thickness 2 m, pot temperature 150°C, load 30 kg) as a substitute for the moldability of the molding material. /cd), and the mold temperature is 170° according to EMM■.
C, the gel time was measured using a JSR model Curelastometer (mold temperature 170'C), and these values are shown in Table 1.

In addition, for actual moldability, after molding the lead frame mounting the aluminum wiring TEG element by 16DIP nitrogen transfer molding, the variflow was
The length of the thin strip formed in the air vent with a thickness of μ was actually measured, wire deformation was determined by observing the degree of deformation of the φ25 μ gold wire with soft X-rays, and the appearance of the 16 DIP molded product was observed for unfilled parts. These results are also shown in Table 1.

In contrast to Comparative Examples 1 and 2, Examples 1 and 2 were made with powder and granules obtained by post-adding a hardening aid with almost the same composition, heating, melting, and kneading, and then cooling and pulverizing. By doing so, it was possible to reduce the melt viscosity and increase the spiral flow even though the gel time was almost the same.
In actual molding of 6DIP, not only the effect of lowering the viscosity but also the reduction of burr flow, which indicates improved wetting of the resin and the inorganic filler, is observed.

As shown in Example 2, if the post-added curing aid contains particles of 100 mesh or more, uniform dispersion may be impaired, resulting in variations in property evaluation values, or mold gate clogging, resulting in poor molding. This is not desirable as it may cause unfilled items.

〔Effect of the invention〕

As mentioned above, by adding the curing aid of the present invention later, heating, melting, kneading, and then cooling and pulverizing, the inorganic filler can be highly filled, while the viscosity is low and there is little occurrence of thin flakes. This makes it possible to produce an epoxy resin molding material with excellent moldability.

Patent applicant Matsushita Electric Works Co., Ltd.

Claims (3)

[Claims] (1) After heating, melting, and kneading a resin composition consisting of (a) an epoxy resin, (b) a phenol novolac curing agent, (c), and an inorganic filler, cooling and grinding the resulting powder into powder and granules, ) A method for producing an epoxy resin molding material, which comprises dispersing a curing aid, heating, melting, and kneading it again, followed by cooling and pulverizing. (2) Claim 1, wherein the curing aid is a solid powder composed of particles of less than 100 mesh.
A method for manufacturing the epoxy resin molding material described. (3) 10 to 20 parts by weight of the epoxy resin as the component (a) and 5 to 20 parts by weight of the phenol novolak curing agent as the component (b).
10 parts by weight, the inorganic filler of component (c) is 400 to 10 parts by weight per 100 parts by weight of the total amount of components (a) and (b).
00 parts by weight, and also 0.00 parts by weight of the curing aid, component (2).
Claim 1 or 2, wherein the composition is blended in a proportion of 0.05 to 5 parts by weight.
A method for manufacturing the epoxy resin molding material described.