JPH03211A - 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 and, at the same time, has low viscosity and is excellent in formability by a method wherein setting assistant is added subsequently. 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. From ten to twenty pts.wt. of the epoxy resin (a) is used. As the phenol-novolak setting agent (b), 5-10 pts.wt. of setting agent such as phenol-novolak resin, cresol-novolak resin, xylenol-novolak resin or the like is used. 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 setting 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 (Field of Industrial Application) 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 loading of non-Ill award fillers. 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, the high viscosity of the molding material leads to wire deformation and breakage within the semiconductor package, and furthermore, there are problems in that the semiconductor device as a molded product is unfilled or voids, which are harmful to moisture resistance.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing an epoxy resin molding material that is highly filled with an inorganic filler, has a low viscosity, and has excellent moldability.

(Means for Solving the Problems) In order to solve the problems, the present inventors have discovered that, before molding, the inorganic filler and the resin are thoroughly kneaded and wetted without substantially progressing the curing of the resin. It was discovered that the viscosity of the molding material can be lowered by using it as a molding material, and the present invention was developed based on this discovery. That is,
The present invention provides (a) an epoxy resin, (b) a phenol novolak curing agent, (c) and
The gist of this article is a method for producing an epoxy resin molding material, which comprises heating, melting, and kneading a resin composition made of an inorganic filler, and then cooling and pulverizing the powder to disperse (d) a curing aid therein. .

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 novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, alicyclic epoxy resins, halogenated epoxy resins, etc., and 10 to 20 parts by weight. It can be used within the range of.

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 Talesol. Novolac resin, xylenol novolank resin, etc. can be used in an amount of 5 to 10 parts by weight.

As the inorganic filler (c), commonly used powders such as crystalline silica, fused silica, alumina, silicon nitride, titanium oxide, calcium carbonate, etc. may be used alone or in combination, and the total amount of components (a) and (b) may be used. 400 to 1000 parts by weight can be used per 100 parts by weight. In particular, high-purity crystalline silica, fused silica, alumina, and silicon nitride are desirable, and the particle size of these inorganic fillers is
A material of less than 100μ is preferable because it does not clog the gate of the molding mold, and it also allows for good wetting of the inorganic filler and the resin.
Coupling agents are added to these inorganic fillers in order to
For example, it can also be treated with epoxysilane, aminosilane, etc.

As the curing aid (d), imidazoles, tertiary amines, etc. are desirable, and the amount used is 0.05 to 5 parts by weight based on the total of 11,100 parts by weight of components (a) and (b). can. 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.

Other 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. is used, and 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) phenol novolak curing agent, component (c) inorganic filler and mold release agent, dyes and pigments, flame retardants, etc.
The ingredients were blended as necessary, and the powder that was applied to a mixing and dispersing machine was formed into a sheet using a hot roll, hardened using a cooling machine, and made into powder using a pulverizer. The hardening aid component (d) is added to this powder and granular material afterward, and the mixture is uniformly dispersed using a mixing and dispersing machine to produce an epoxy resin molding material.

〔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 novolac resin (○H) as curing agent
100 parts by weight of crystalline silica was used as an inorganic filler, and 0.0% of an epoxy silane coupling agent was used to modify the surface of the crystalline silica.
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 heated roll at 100°C. The process was repeated 25 times, then cooled and crushed to form powder, and as a hardening agent, 0.1% of 2-methylimidazole with a particle size of less than 1001791 was added.
Parts by weight were added, uniformly dispersed, and mixed to obtain an epoxy resin molding material.

Example 2 An epoxy resin molding material was prepared in exactly the same manner as in Example 1, except that the blending ratio of the hardening aid 2-methylimidazole in Example 1 was changed to 0.2 parts by weight.

Example 3 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 With the same component composition as in Example 1, the hardening aid 2-methylimidazole was uniformly dispersed from the beginning along 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, molding is prohibited. The hardening had progressed to the point where it could not be removed.

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, load 30 kg/cd, bot temperature 150°) as a substitute for the moldability of the molding material. In C), the spiral flow was performed according to EMM r at a mold temperature of 170°C,
Measure the gel time using a JSR type Curelastometer (mold temperature 1).
70'C), and these values are shown in Table 1. In addition, as for actual formability, aluminum wiring T
After molding the lead frame with the EG element mounted on it using 16DIP transfer molding, wire deformation was determined by observing the degree of deformation of the φ25μ gold wire using soft X-rays, and voids were determined by observing the appearance of the 16DIP molded product. If there is a hole with a diameter of 0.3 or more, it will be judged as ×, and if it is not filled, it will be judged as 16.
The appearance of the 0IP molded product was observed and judged, and the results are also shown in Table 1.

In Example 1, compared to Comparative Example 1, by changing the timing of addition of the curing aid with the same formulation, the melt viscosity was significantly reduced,
Spiral flow can be greatly increased, 16
Good results have also been shown in actual DIP molding. Also,
Although Example 2 had the same gel time as Comparative Example 1, by changing the timing of addition of the curing aid, the melt viscosity was significantly lowered and the spiral flow was significantly increased. It also shows good moldability when molded. However, as shown in Example 3, when the post-added curing aid contains particles of 100 mesh or more,
It is undesirable that uniform dispersion is impaired, resulting in variations in the characteristic evaluation values, or that the gate of the mold is clogged, resulting in unfilled molded products.

〔Effect of the invention〕

As described above, by adding the curing aid of the present invention later, it is possible to manufacture an epoxy resin molding material that is highly filled with inorganic fillers, has low viscosity, and has excellent moldability. It is.

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. (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.