JPH04314725A - Resin composition - Google Patents

Abstract

PURPOSE:To prepare a semiconductor-sealing resin compsn. excellent in resistance to soldering heat and humidity by compounding an epoxy resin, a specific phenol novolac curative, a cure accelerator, and an inorg. filler. CONSTITUTION:A resin compsn. which comprises an epoxy resin, a phenol novolac curative contg. 30-100wt.% phenol novolac curative of the formula [wherein 0.05<=n/(1+m+n)<=0.5] having an imide ring and a naphthalene ring, a cure accelerator, and an inorg. filler. An epoxy resin contg. a minimized amount of ionic impurities, such as Na<+> or Cl<-> is pref. The curative gives the compsn. not only favorable properties for a high resistance to soldering heat, i.e. a low water absorption, a high toughness, and a good adhesion to metal, but also a high Tg and a high curability. Any accelerator which increases the rate of reaction between epoxy groups and phenolic hydroxyl groups may be used.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having excellent solder heat resistance and suitable for use as a resin composition for encapsulating highly integrated ICs.

0002

[Prior Art] Conventionally, electronic components such as diodes, transistors, and integrated circuits have been encapsulated with thermosetting resin, but especially for integrated circuits, 0-cresol novolac epoxy resin, which has excellent heat resistance and moisture resistance, has been encapsulated with novolac resin. Epoxy resin cured with phenolic resin is used. However, in recent years, as integrated circuits have become more highly integrated, chips have become larger and larger, and packages have changed from the conventional DIP type to surface-mounted small, thin flat packages, SOP,
They are changing to SOJ and PLCC.

That is, when a large chip is encapsulated in a small and thin package, problems such as the generation of cracks due to stress and a decrease in moisture resistance due to these cracks have been brought into focus. In particular, problems have arisen in that moisture resistance deteriorates due to cracking of the package and peeling of the resin and chip due to sudden exposure to high temperatures of 200° C. or higher during the soldering process.

It has been desired to develop a highly reliable sealing resin composition suitable for sealing these large chips. To solve these problems, in order to alleviate the thermal shock during soldering, thermoplastic oligomers are added (Japanese Patent Application Laid-Open No. 115849/1984) and various silicone compounds are added (Japanese Patent Application Laid-open No. 11585/1983). , 62-116
654 Publication, 62-128162 Publication), and silicone modification (Japanese Patent Application Laid-open No. 62-136860), but all of these methods cause cracks in the package during soldering, resulting in poor reliability. However, it has not been possible to obtain an epoxy resin composition for semiconductor encapsulation.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that has excellent soldering heat resistance and moisture resistance.

[0006]

[Means for Solving the Problems] In order to solve these problems, the present inventors conducted extensive research and discovered a resin composition having the following composition. Epoxy resin and the following formula (1
) A phenol novolac curing agent containing an imide ring and a naphthalene ring is blended in an amount of 30 to 100% by weight in the total amount of curing agent,

[0007]

##STR00002## The present inventors have discovered that a resin composition for semiconductor encapsulation that can improve the above-mentioned problems can be obtained by further blending a curing accelerator and an inorganic filler, leading to the completion of the present invention.

[0008] The epoxy resin as component (A) used in the present invention refers to any resin having two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, biphenyl type epoxy resin, novolak type epoxy resin, or modified products thereof are shown. It is desirable that these epoxy resins contain as few ionic impurities as Na+, Cl-, etc. as possible.

The imide ring- and naphthalene ring-containing phenolic novolak curing agent as component (B) used in the present invention has effective effects on soldering heat resistance, namely low water absorption,
In addition to having good toughness and adhesion to metals, Tg
It has the characteristics of high hardness and hardenability. This effect is due to the molecular structure. The side chain of the molecule contains naphthalene, which has a hydrophobic planar structure, which allows for good packing, resulting in low water absorption and toughness. Also, N of the imide ring,
The introduction of a polar structure by O also improves adhesion to metals, making it possible to achieve good soldering heat resistance and moisture resistance after soldering.

Furthermore, moldability and Tg are important parameters for resin compositions for semiconductor encapsulation, and this curing agent satisfies these requirements. The naphthalene ring and imide ring improve Tg and provide good curability. In the imide ring- and naphthalene ring-containing phenol novolak represented by formula (1), the value of n/l+m+n is 0.
．． 05 or more and 0.5 or less is desirable. When it is less than 0.05, the effect of the imide ring and naphthalene ring is small and the soldering heat resistance is insufficient. When it is larger than 0.5, the amount of phenolic OH is very small, resulting in a decrease in curability, Tg, etc.

The imide ring- and naphthalene ring-containing phenol novolak represented by formula (1) accounts for 3% of the total amount of curing agent.
It is necessary to account for 0 to 100% by weight. If it is less than 30% by weight, the above effects will not be sufficiently exhibited and the soldering heat resistance will decrease. The curing agent used in combination may be any curing agent as long as it has phenolic OH in its molecule, such as a phenol novolac curing agent.

The curing accelerator as component (C) of the present invention may be any one as long as it promotes the reaction between the epoxy group and the phenolic hydroxyl group, and a wide variety of those commonly used in sealing materials may be used. For example, 3rd party such as BDMA etc.
Organic phosphorus compounds such as class amines, imidazoles, 1,8-diazabicyclo[5,4,0]undecene-7, and triphenylphosphine are used alone or in combination of two or more. Examples of the inorganic filler as component (D) of the present invention include crystalline silica, fused silica, alumina, calcium carbonate, talc, mica, glass fiber, etc.
These may be used alone or in a mixture of two or more. Among these, crystalline silica or fused silica is particularly preferably used.

[0013] In addition, mold release agents such as waxes, flame retardants such as hexabromobenzene, decabromo biphenyl ether, and antimony trioxide, carbon black,
A coloring agent such as red iron oxide, a silane coupling agent, a thermoplastic resin, etc. may be appropriately added and blended. A general method for producing the epoxy resin composition for semiconductor encapsulation of the present invention is to thoroughly mix raw materials in a predetermined blending ratio using a mixer, etc., and then melt-knead them using a roll, kneader, etc. It can then be easily produced by cooling, solidifying, and pulverizing into an appropriate size.

[0014]

[Examples] The present invention will now be specifically illustrated by Examples and Comparative Examples.

Example 1 0-cresol novolak type epoxy resin
90 parts by weight
(Softening point: 65°C, epoxy equivalent: 210)

Brominated bisphenol A type epoxy resin
(Softening point: 65°C, bromine content: 37%, epoxy equivalent: 370) 10 parts by weight Phenol novolak resin containing imide ring and naphthalene ring (d) 95
Part by weight: Crushed fused silica

300 parts by weight antimony trioxide

10 parts by weight Silane coupling agent
2
Part by weight Triphenylphosphine

2 parts by weight carbon black

3 parts by weight carnauba wax

Thoroughly mix 3 parts by weight at room temperature and further heat to 95-100℃
The mixture was kneaded using twin-screw rolls, cooled, and then ground to obtain a molding material, which was then made into tablets to obtain an epoxy resin composition for semiconductor encapsulation. This material was molded using a transfer molding machine (molding conditions: mold temperature 175°C, curing time 2 minutes), and the resulting molded product was post-cured at 175°C for 8 hours and evaluated. The results are shown in Table 1.

Example 2 95 parts by weight of the imide ring- and naphthalene ring-containing phenol novolak resin (2) of Example 1 were mixed with 60 parts by weight of the imide ring- and naphthalene ring-containing phenol novolak resin (2) and the phenol novolac resin (softening point 110). °C, O
Example 1 except that the H equivalent was changed to 110) 20 parts by weight.
An epoxy resin composition for semiconductor encapsulation was obtained in the same manner as above. Table 1 shows the evaluation results of this epoxy resin composition for semiconductor encapsulation.
Shown below.

Epoxy resin compositions for semiconductor encapsulation having the compositions shown in Table 1 were obtained in the same manner as in Examples 3 and 4 and Comparative Examples 1 to 4. The results are shown in Table 1.

[0018]

[Table 1] A. 0-Cresol novolac epoxy resin softening point 65
°C, epoxy equivalent 210 b. Biphenyl type epoxy compound Formula (2) Epoxy equivalent 195

[0019]

[C3] C. Brominated bisphenol A type epoxy resin softening point 65
°C, bromine content 37%, epoxy equivalent 370 n. Phenolic novolac resin containing imide and naphthalene rings
Formula (3) Softening point: 120°C, OH equivalent: 193

[0020]

[C4] E. Phenol novolac resin containing imide ring and naphthalene ring Formula (4) Softening point 110°C, OH equivalent 119

[0021]

[C5] f. Phenol novolac resin containing imide ring and naphthalene ring Formula (5) Softening point 148°C, OH equivalent 520

[0022]

[C6] to. phenolic novolak resin Softening point: 110℃, OH equivalent: 110

Evaluation method *1 After molding at 175°C for 2 minutes, 10 minutes after the mold opens
Bacall hardness of the molded product after seconds. *2 Measured using a Tensilon bending tester at 250°C and a loading rate of 10mm/min. Span 64mm, width 10
3-point bending with a thickness of 4 mm. *3 85℃ for 20 molded products (chip size 36mm2, package thickness 2mm)
After 72 hours of treatment under water vapor at 85% RH, IR reflow treatment at 240°C was performed, and the number of cracks generated is shown. *4 For 20 molded products (chip size 36mm2, package thickness 2mm), 215
After VPS treatment at ℃, 125℃, 100%R
The number of IC chips that failed after 500 hours of treatment under H water vapor is shown.

[0024]

[Effects of the Invention] The composition of the present invention has excellent soldering heat resistance and moisture resistance, and is extremely reliable as a resin composition for encapsulating highly integrated ICs.

Claims (1)

[Claims] Claim 1: (A) epoxy resin, (B) the following formula (
1) A phenol novolak curing agent containing an imide ring and a naphthalene ring containing phenol novolak curing agent [Chemical 1] from 30 to 100% by weight based on the total amount of curing agent, (C) a curing accelerator, and (D)
) An epoxy resin composition for semiconductor encapsulation characterized by containing an inorganic filler as an essential component.