JPS61221223A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:The titled composition excellent in heat shock resistance and moisture resistance, comprising a specified epoxy resin, a novolak phenolic resin, PS or a styrene/vinyl compound copolymer and an organic phosphine compound. CONSTITUTION:100pts.wt. epoxy resin (A) having at least two epoxy groups in the molecule (e.g., bisphenol A diglycidyl ether) is melt-kneaded with 40-65 pts.wt. novolak phenolic resin (B) of a softening point of 60-120 deg.C and a hydroxyl equivalent of 100-150, 1-20pts.wt. PS or styrene/vinyl compound (e.g., acrylonitrile) copolymer (C) of an average particle diameter of 0.2-30mum and 0.01-20 pts.wt. organic phosphine compound (D) (e.g., trimethylphosphine).

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an epoxy resin composition for encapsulating a semiconductor device, and more specifically, an epoxy resin composition for encapsulating a semiconductor having excellent thermal shock resistance and moisture resistance. It is related to.

[Technical background of the invention and its problems]

In recent years, in the field of encapsulation of semiconductor devices, as semiconductor devices have become highly integrated, various functional units on the devices have become finer and the device pellets themselves have become larger. Due to these changes in element pellets, conventional encapsulating resins are no longer able to satisfy requirements such as thermal shock resistance. Conventional.

Epoxy resin compositions cured with phenol zumerank resin, which are used as sealing resins for semiconductor devices, have excellent hygroscopicity, high-temperature electrical properties, moldability, etc., and have become the mainstream resin for molding.

However, when this type of resin composition is used to seal a large device pellet with a fine surface structure, phosphosilicate glass (PSG), which is a coating material to protect the aluminum (AJ) pattern on the surface of the device pellet, is sealed. ) film or silicon nitride (SiN) film, or cracks in the element pellet.

This tendency is particularly significant when a thermal cycle test is performed. As a result, defects such as defects in element characteristics due to pellet cracking and defects due to corrosion of the AJ pattern due to cracks in the protective film occur.

As a countermeasure, the stress on the internal encapsulation of the encapsulation resin should be reduced, and the P2O film or SiN film on the encapsulation resin and the element should be
It is necessary to increase the adhesion with glass films such as membranes.

Furthermore, in order to prevent corrosion of the Al/4' turns on the element surface as much as possible, the cured product contains hydrolyzable halodan compounds, especially low chlorine concentration, and high electrical insulation performance during moisture absorption and high temperatures. need to be kept at the level. Yosi,
Conceivable measures include lowering the elastic modulus of the sealing resin, lowering the coefficient of thermal expansion, increasing the glass transition point, and lowering the molding shrinkage rate. For example, JP-A-59-75922 describes a method of reducing the strain stress of a resin by using a styrenic block copolymer.

[Object of the Invention] An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that solves the above-mentioned problems and has excellent thermal shock resistance and moisture resistance.

[Summary of the invention]

In order to achieve the above object, the present inventors, as a result of intensive research, discovered that by adding polystyrene or styrene to an epoxy resin having at least two epoxy groups in one molecule as a curing agent, An epoxy resin composition containing a copolymer of a vinyl compound and an organic phosphine compound as a curing accelerator has excellent thermal shock resistance and moisture resistance, and can be used as a sealing material for semiconductor devices.

They found that it was good and completed the present invention.

That is, the present invention relates to an epoxy resin composition for semiconductor encapsulation characterized by comprising the following components.

(4) 100 parts of epoxy resin having at least two epoxy groups in one molecule (B: 40 to 65 parts by weight of novolak type phenol resin; 0 to polystyrene or 1 to 20 parts by weight of copolymer of styrene and a vinyl compound; [F] organic Phosphine compound 0.01 to 20 parts by weight The epoxy resin (4) according to the present invention may be any resin as long as it contains at least two epoxy groups in the molecule, for example, bisphenol Ao diglycidyl. Ether, putasoene diepoxide, 3,4-epoxycyclohexylmethyl-(3,4-epoxy)cyclohexanecarxylate, vinylcyclohexane dioxide, 4.4'-y(l,2-epoxyethyl)diphenyl ether, 4. 4'-(1,2-epoxyethyl)biphenyl, 2,2-bis(3,4-epoxycyclohexyl)propane, glycidyl ether of resorcinol, soglycidyl ether of phloroglucin, diglycidyl ether of methylfuro-tetraglucin, bis- (2,3-epoxycyclobentyl)ether, 2-(3,4-epoxy)cyclohexane-5,5-spiro(3,4-epoxy)-cyclohexane-m-dioxane, bis-(3,4
-epoxy-6-methylcyclohexyl) asbate,
N, N'-m-phinyl bis(4,5-epoxy-1
, 2-cyclohexane) difunctional epoxy compounds such as socarpoxiimide, triglycisol ether of para-aminophenol, polyallyl glycidyl ether, 1
, 3.5-tri(l,2-epoxyethyl)benzene,
2, 2'.

Epoxy compounds having trifunctionality or higher are used, such as 4'-tetraglycidic benzophenone, polyglycidyl ether of phenol formaldehyde, triglycidyl ether of glycerin, and triglycidyl ether of trimethylolpropane. The above compounds are selected depending on the use and purpose.

Two or more types can also be used in combination.

The blending ratio of this component (2) is 1 part by weight,
It is preferable to mix up to 25 parts by weight of a flame-retardant epoxy resin to 100 parts by weight of the epoxy resin. Examples of the resin in this case include brominated epoxyl lac type resin, brominated bisphenol A type resin, and the like.

The nolac type phenolic resin of component (■) according to the present invention is:
Any compound having at least two phenolic hydroxyl groups in one molecule may be used.For example,
Phenolic resins include lac resin, ortho-cresol novolac resin, and meta-cresol novolac resin,
These may be used alone or in a mixed system of two or more.

Among the above novolac type phenolic resins, the softening point is 60-
Those having 120'Ct- are preferred, and those having 80 to 100'C&- are particularly preferred.

Those having a hydroxyl group of 11,100 to 150 are preferable,
Particularly preferred is one having a molecular weight of 100-110.

The blending ratio of component (1) is usually 40 to 65 parts by weight, preferably 45 to 55 parts by weight. If the blending ratio is less than 40 parts by weight and 115 S, the strength of the cured mineral resin product will be weakened, which is undesirable. On the other hand, if it exceeds 65 parts by weight and 1 part, the moisture resistance of the sealing resin will deteriorate, which is not preferred.

Examples of copolymers of styrene and vinyl compounds with zero components according to the present invention include styrene, α-methylstyrene, vinyltoluene, novinylbenzene, t-butylstyrene, tutadiene isoprene, ethylene, tstyrene, and acrylonitrile. Specific examples include Hymer S (Sanyo Kasei Co., Ltd. (2)), Fine Var 3000sp, or Fine Pearl 3000.
F (all manufactured by Sumitomo Chemical), etc.

(In terms of moldability, the average particle size of component 0 is 0.2 to 30 μm.
The thickness is preferably 1.0 to 1.2 μm.

The blending ratio of component 0 is 1 to 20 parts by weight, preferably 3 to 15 parts by weight. If the amount is less than 1 part by weight, sufficient thermal shock resistance cannot be obtained.

If the number of overlapping parts exceeds 20, a significant increase in viscosity will result.

The organic phosphine compound as component (2) according to the present invention is.

A curable epoxy resin curing accelerator using phenolic resin. Such an organic phosphine compound may be any compound that is normally used as a curing accelerator, such as trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tri(p-methylphenyl ) Phosphine.

selected from the group consisting of tri(nonylphenyl)phosphine, methyldiphenylphosphine, nophthylphenylphosphine, tricyclohexylphosphine, 1,2-bis(diphenylphosphine)ethane, bis(diphenylphosphine)methane, etc. 1 m or two or more types are used.

The blending needle of the above-mentioned organic phosphine compound is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 5 parts by weight, based on 10,011 parts of the epoxy resin. If the amount is less than 0.01 part, the curing speed will decrease, while if it exceeds 20 parts by weight, the heat resistance,
Moisture resistance and electrical characteristics deteriorate.

Next, a method for manufacturing the epoxy resin for semiconductor blocking of the present invention will be described.

The composition of the present invention can be prepared by melt-mixing the above-mentioned components using heated rolls, bath melt-kneading using a kneader, bath-melt kneading using an extruder, mixing using a special mixer after pulverization, or using any of these methods as appropriate. It can be easily manufactured by combining various combinations.

The composition of the present invention may optionally contain a curing accelerator such as imidazole or a derivative thereof, a tertiary amine derivative, a phosphine derivative, a cycloaminone derivative; turcon, silica, fused silica glass, alumina, hydroxide. aluminum, glass, quartz glass, calcium silicate,
Stone powder, calcium carbonate, magnesite, clay, kaolin, Merck, iron powder, copper powder, mica, asbestos, silicon carbide, boron nitride, molybdenum dioxide, lead compounds, lead oxide, zinc white, titanium white, carbon black, etc. fillers; release pieces such as higher fatty acids and waxes; coupling agents such as epoxysilane, vinylsilane, aminosilane, melan compounds, alkoxytitanate compounds, and aluminum chelate compounds; antimony, phosphorus compounds,
A known flame retardant containing bromine or chlorine may be blended.

〔Effect of the invention〕

The epoxy resin composition for encapsulating semiconductor devices of the present invention has excellent thermal shock resistance and moisture resistance, and has great practical value in applications such as highly integrated semiconductor devices.

The present invention will be further explained in detail by giving Examples and Comparative Examples below, which are extremely large. In addition, in Examples and Comparative Examples, all "parts" indicate "junior parts".

[Embodiments of the invention]

[Examples 1 to 6] Orthocresol novolac type epoxy resin (softening point 7
0°C, 100 parts of epoxy (1:216).

Brominated phenolic epoxy resin (bromine content 13096, softening point 287°C, epoxy ratio 285
) 14 parts, phenol novolak resin (softening point 90°C,
50 parts of hydroxyl group (1:104), 1.5 parts of curing accelerator triphenylphosphine, 1 part of carnauba wax as mold release agent.
．． 2 parts, 1.8 parts of carbon powder as a colorant, 405 parts of fused silica powder as a filler, 11i antimony trioxide powder as a flame retardant aid, and an epoxysilane coupling agent as a coupling agent between the filler and the resin. 4 parts were blended, and further polystyrene and polystyrene copolymer were added and blended according to the formulation table in Table 1. Next, the mixture was mixed with a two-wheeled roll at 65 to 110°C, cooled, and then crushed to form tablets to obtain the epoxy resin composition for semiconductor encapsulation of the present invention.

[Comparative Examples 1 to 3] The same composition as in Example except that 2.0 parts of 2-wandecylimidazole was used in place of 1.5 parts of triphenylphosphine, the curing accelerator in Example, and further the same composition as in Table I was used. Each ingredient in the recipe? An epoxy resin composition for sealing a balloon conductor was obtained by the same manufacturing method as in the example.

Using the compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 3, a low pressure transfer molding machine (175°C, 80K
f/d 180 seconds), a large pellet evaluation sample element (811II x 8 units) having an i-plane IcPsG layer was sealed. In addition, A on the surface without the Bassi Bakyon layer.
/Sealing was performed using elements of the same bullet size with wiring layers exposed.

The following tests were conducted to evaluate the thermal shock resistance and moisture resistance of the obtained sample element.

Thermal shock resistance test: Samples were subjected to cooling and heating cycles from -65°C to 1.50°C, and property defects were measured.

After measurement, the element having the PSG layer and the surface A/A# element molded product were molded using fuming nitric acid, and the resin was removed by bathing.
The presence or absence of cracks in the PSG layer and the A of the Al wiring layer, respectively.
1 movement was observed under a microscope.

Humidity deterioration test 2A! Sealed element fc2 for wiring corrosion measurement
It was exposed to saturated steam at 5 atm for each test period, and pass/fail was judged based on disconnection due to A corrosion.

In addition, as other properties of the resin, tests were conducted on volume resistivity, glass transition point, and flexural modulus.

Volume resistivity: 175°C according to JIS K-6911
× After cure after transfer molding for 3 minutes - 175
This was carried out using a sample treated with 9CX for 8 hours. The measurement conditions were as follows: DC 500V applied, volume resistivity measured at 150°C for 1 minute. The glass transition point was measured at an elevated temperature of 5° C. using a thermal dilatometer.

Bending elastic modulus: Tested according to JIS K-6911 using molded and processed samples similar to the above-mentioned edges.

[Results of the invention]

As is clear from the results in Table 2, the products of the present invention of Examples were clearly superior to the comparative products. For example, in thermal shock resistance tests, the number of defective products is extremely small.
The occurrence of G cracks is also slow, at least 6° cycles, and
There was almost no wiring movement.

In the moisture resistance test, the number of defective products was also very small.

In addition, it also showed good values for volume resistivity, glass transition point, and flexural modulus as a material for semiconductor encapsulation.

Claims (1)

[Claims] 1 (A) 100 parts by weight of an epoxy resin having at least two epoxy groups in one molecule (B) 40 to 65 parts by weight of a novolac type phenol resin (C) Polystyrene or a copolymer of styrene and a vinyl compound An epoxy resin composition for semiconductor encapsulation, comprising 1 to 20 parts by weight of a combination and 0.01 to 20 parts by weight of (D) an organic phosphine compound.