JPH0214237A - Resin composition for sealing - Google Patents

Abstract

PURPOSE:To provide a sealing resin composition containing an epoxy resin, a novolak phenolic resin, a saturated thermoplastic elastomer and an inorganic filler as essential components, having low residual stress and excellent crack resistance and useful for the sealing of electronic and electrical parts. CONSTITUTION:The objective sealing resin composition contains (A) an epoxy resin (e.g., cresol novolak resin), (B) a novolak phenolic resin (e.g., epoxidized novolak phenolic resin), (C) a saturated thermoplastic elastomer (e.g., Toughtec(R) a product or Asahi Chemical Ind.) and (D) an inorganic filler, preferably silica powder or alumina, as essential components, wherein the amounts of the components C and D are 0.15-5wt.% and 25-90wt.% based on the whole composition, respectively, and the equivalent ratio of the epoxy group of the component A to the phenolic OH of the component B is 0.1-10. The composition can be produced e.g., by thoroughly mixing the above components with a mixer, etc., to form a homogenous mixture, melting and mixing the mixture with a hot roll, etc., cooling the molten mixture and crushing the solidified material.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a sealing resin composition that is low stress and has excellent crack resistance and is used for sealing electronic and electrical components.

(Prior Art) Conventionally, methods have been used to seal electronic components such as diodes, transistors, and integrated circuits using thermosetting resins. This resin sealing is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use. Among thermosetting resins used as sealing resins, epoxy resins are most commonly used. Hardening agents such as acid anhydrides, aromatic amines, and novolak-type phenolic resins are used in epoxy resins. Among these hardening agents, epoxy resins using novolac type phenolic resin as hardening agents are
Compared to materials using other curing agents, it has excellent moldability and moisture resistance, is non-toxic, and is inexpensive, so it is widely used as a semiconductor encapsulation material.

(Problems to be Solved by the Invention) In recent years, in the fields of semiconductors and integrated circuits, there has been an increase in the degree of integration of elements and the increase in the size of pellets. The epoxy resin used for this purpose shrinks during molding and puts stress on the semiconductor element.
The drawback is that it is less reliable. When performing hot and cold cycle tests on molded products (sealed products) using these resins,
There was a drawback that open bonding wires, resin cracks, and pellet cracks occurred, making it impossible to achieve Re5 as an electronic/electrical component.

The present invention was made to eliminate these drawbacks, and is low stress and has excellent crack resistance.It does not apply stress to semiconductor elements, etc., and has "reliability" that does not cause wire opens or cracks. The purpose of the present invention is to provide a sealing resin composition with a high

[Structure of the Invention] (Means for Solving the Problems) As a result of intensive research aimed at achieving the above object, the present inventors have discovered that by introducing a saturated thermoplastic elastomer, the The present invention was completed based on the discovery that a resin composition with low shrinkage, low stress, and excellent crack resistance can be obtained. That is, the present invention includes (A>epoxy resin, ([3) novolak phenol resin, (C) saturated thermoplastic elastomer, and (D) inorganic filler] as essential components, and with respect to the entire resin composition, Said (C
) 0.1-5% by weight of saturated thermoplastic elastomer,
Moreover, it is a resin composition for sealing characterized by containing 25 to 90@% of the inorganic filler of the above (D). For sealing, the equivalent ratio [(a)/(b)] between the epoxy group (a) of the epoxy resin and the phephenolic hydroxyl group (b) of the novolac type phenolic resin is within the range of 0.1 to 10. It is a resin composition.

As long as the epoxy resin (A) used in the present invention is a compound that has at least two epoxy groups in its molecule, There are no particular restrictions on the composition or molecular weight, and a wide range of materials commonly used for sealing materials can be included. Examples include aromatic resins such as bisphenol type, alicyclic resins such as cyclohexane derivatives, and epoxy novolak resins represented by the following general formula.

(However, in the formula, R1 represents a hydrogen atom, a halogen atom, or an alkyl group, R2 represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins may be used alone or in combination of two or more. use.

The novolak phenol resin (B) used in the present invention includes novolak phenol resins obtained by reacting phenols such as phenol and alkylphenols with formaldehyde or paraformaldehyde, and modified resins thereof, such as epoxidized or gtylated resins. Examples include boratsuya phenol resin. These resins may be used alone or in combination of two or more.

The blending ratio of the novolac type phenolic resin is as described above in <A>.
It is desirable that the equivalent ratio [(a)/(b)] between the epoxy % (a) of the epoxy resin and the phenolic hydroxyl group (b) of the (13) novolac type phenolic resin is within the range of 0.1 to 10. If this equivalent ratio is less than 0.1 or more than 10, the moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, and either case is unfavorable. Therefore, it is limited within the above range.

Examples of the saturated thermoplastic elastomer (C) used in the present invention include Tafdzuku (manufactured by Asahi Kasei Kogyo Co., Ltd., trade name), which may be used alone or in combination of two or more. The blending ratio of saturated thermoplastic elastomer is
The content is preferably 0.1 to 10% by weight based on the entire resin composition.

If the proportion is less than 0.1% by weight, it will not be effective in reducing stress;
Moreover, if it exceeds 10% by weight, the thickening effect becomes significant, making it unsuitable for practical use.

Examples of the DJ inorganic filler used in the present invention include silica powder, alumina, antimony dioxide, talc, calcium carbonate, titanium white, clay mica, red iron oxide, glass fiber, and carbon fiber, which may be used alone or in combination of two or more. Among them, silica powder and alumina are preferably used.The blending ratio of the inorganic filler is as follows:
25-90 f for the entire resin composition! If the proportion is less than 25% by weight, it will have no effect on moisture resistance, INI heat resistance, mechanical properties, and formability, and if it exceeds 90% by weight, the bulk will be large and the formability will be poor, making it impractical for practical use. Not suitable for

The sealing resin composition of the present invention may contain an epoxy resin, a novolak phenolic resin, a saturated thermoplastic elastomer, and an inorganic filler as essential components, or may contain, as necessary, e.g. natural waxes,
Static waxes such as synthetic waxes, metal salts of straight chain fatty acids, acid amides, Nisdels, paraffins, flame retardants such as chlorinated paraffins, bromotoluene, hexabromobenzene, antimony dioxide, carbon black, pen strength, Coloring agents such as, silane coupling agents, various curing accelerators, etc. can be added and blended as appropriate.

A general method for producing the sealing resin composition of the present invention as a molding material consists of epoxy resin, FC lac type rough henol resin saturated thermoplastic elastomer, inorganic filler, and other raw materials selected in a predetermined composition ratio. After mixing in the F direction using a mixer or the like, the mixture is further melt-mixed using hot rolls or mixed using a kneader or the like, then cooled and solidified, and pulverized to an appropriate size to form a molding material. The molding material thus obtained can be applied to sealing, covering, insulating, etc. electronic or electrical components.

(Function) In the sealing resin composition of the present invention, by blending the saturated (1) thermoplastic elastomer, flexibility can be imparted to the resin composition and stress can be relaxed to reduce stress.

(Examples) Next, the present invention will be specifically explained by examples, but the present invention is not limited by the following examples.
In the following Examples and Comparative Examples, "1%" means 1% by weight.
” means.

Example 1 Cresol novolak epoxy resin (epoxy t21
5) 18%, novolac type phenolic resin (phenol 41107), 9%, Toughtic 111041
(manufactured by Asahi Kasei Industries, trade name) 3%, fused silica powder 69
%, curing accelerator 0.3%, ester wax 0.3%
and 14% silane coupling agent O are mixed at room temperature,
The mixture was further kneaded at 90 to 95°C, cooled, and then ground to obtain a molding material. This molding material was transfer-injected into a mold heated to 170° C. and cured to produce a molded product (sealed product).

This molded article was tested for properties related to moisture resistance, stress, etc., and the results are shown in Table 1. Hff of the present invention
A positive effect was observed.

Example 2 Cresol novolac epoxy resin (epoxy equivalent weight 21
5) 18%, novolac type phenol resin (phenol 11107) 9%, Toughtic H1041 manufactured by Asahi Kasei Kogyo Co., Ltd. (trade name) 1.5%, silica powder 69%, curing accelerator 0.3%, Nisdel wax 0. 3% of the silane coupling agent and 0.4% of the silane coupling agent were mixed, kneaded, and pulverized in the same manner as in Example 1 to obtain a molding material. A molded article was also obtained in the same manner, and the molded article was tested for moisture resistance, stress, and other related properties in the same manner as in Example 1, and the results are shown in Table 1. The 2W effect of the present invention was observed.

Comparative example Talesol novolak epoxy resin (epoxy equivalent: 21
5) To 20%, add 10% novolac type phenolic resin (phenol 107), 69% silica powder, 0.3% curing accelerator, 0.3% ester wax and 0.4% silane coupling agent. The mixture was mixed, kneaded, and crushed in the same manner as in Example 1 to obtain a molding material.

This molding material was used to make a molded article, and the properties of the molded article were tested in the same manner as in Example 1. The results are shown in Table 1.

Table (Units) The number of cracks is 30x 25x A copper plate of 25x 25x 31 is embedded in the bottom of a 5111 molded product, and the temperature is -40℃.
The resin was placed in a constant temperature bath at 200° C. for 30 minutes each, and cracks in the resin were investigated after 15 cycles were repeated.

*2:1) Glue a commercially available strain gauge to the island part of the IP16-pin lead frame, and
Measure the strain after time curing.

[Effect of the invention 1] As is clear from the above explanation and Table 1, the sealing resin composition of the present invention has low stress and excellent crack resistance, so it does not cause open bonding wires, resin cracks, No pellet cracks occur, and stress caused by shrinkage during curing is low.

Therefore, by using this resin composition, electronic/electrical parts with high reliability can be obtained.

Claims (1)

[Scope of Claims] 1 (A) an epoxy resin, (B) a novolak type phenolic resin, (C) a saturated thermoplastic elastomer, and (D) an inorganic filler are essential components, and the above-mentioned components are added to the entire resin composition. (C)
A sealing resin composition comprising 0.1 to 5% by weight of the saturated thermoplastic elastomer and 25 to 90% by weight of the inorganic filler (D). 2 Equivalent ratio of the epoxy group (a) of the epoxy resin to the phenolic hydroxyl group (b) of the novolak type phenolic resin [(
a)/(b)] is within the range of 0.1 to 10.