JP2001261939A - Liquid resin composition and semiconductor device by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid resin composition with high reliability, exhibiting good reflow resistance even if a reflow temperature is changed to 260 deg.C according to the trend directed to lead-free state, and further to provide a package with the high reliability by using the liquid resin composition. SOLUTION: This liquid resin composition comprises a filler (A), a liquid epoxy resin (B), a bismaleimide compound and/or a prepolymer thereof (C), and a curing agent (D), regulated so that the amount of the component (C) may be 4-35 pts.wt. based on 100 pts.wt. epoxy resin (B). The semiconductor device is obtained by using the liquid resin composition as a die attach paste.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid resin composition for bonding a semiconductor element such as an IC or an LSI to a metal frame or the like.

[0002]

2. Description of the Related Art With an increase in awareness of environmental issues in recent years, studies have been actively conducted to replace solder used in a process of mounting a semiconductor product on an organic substrate with lead-free solder. For this reason, the reflow temperature also needs to be changed from the conventional 220 ° C. or 240 ° C. to 260 ° C., and the reflow resistance at a higher temperature has also been required for semiconductor product components. However, the conventional die attach material can be used at a reflow temperature of up to 240 ° C., but none of them can withstand 260 ° C. reflow.

[0003]

SUMMARY OF THE INVENTION The present invention provides a highly reliable liquid resin composition exhibiting good reflow resistance even when the reflow temperature is changed to 260 ° C. with the trend of lead-free. An object of the present invention is to provide a highly reliable package by using the liquid resin composition of the present invention.

[0004]

The present invention provides a filler (A), a liquid epoxy resin (B), a bismaleimide compound represented by the general formula (1) and / or a prepolymer (C) thereof, and a curing agent (D). And the amount of (C) is 4 to 35 parts by weight based on 100 parts by weight of the liquid epoxy resin.

Embedded image

Further, there is provided a semiconductor device manufactured by using the above liquid resin composition as a die attach material.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The filler used in the present invention is desirably used in semiconductor applications in an amount of 10 ppm or less of ionic impurities such as halogen ions and alkali metal ions. In addition, depending on the required characteristics, metal fillers such as silver, gold, copper, and nickel, inorganic fillers such as silica, aluminum nitride, and boron nitride, or calcined phenol particles,
Organic fillers such as polyimide particles can be used alone or in combination.

[0007] Flakes, fibers, resins, amorphous or spherical shapes can be used alone or in combination. Further, with respect to the particle size, usually, the average particle size is preferably 2 to 10 μm and the maximum particle size is preferably about 50 μm, and a mixture of a relatively fine filler and a coarse filler may be used.

The epoxy resin used in the present invention is limited to a liquid one. However, if the epoxy resin is not liquid at ordinary temperature, a solvent is required for kneading with the filler. The solvent is not preferable because it causes bubbles and lowers the adhesive strength and thermal conductivity of the cured product. Here, the epoxy resin which is liquid at ordinary temperature includes, for example, an epoxy resin which is solid at ordinary temperature and shows a stable liquid at ordinary temperature by being mixed with the epoxy resin which is liquid at ordinary temperature. For use in semiconductor applications, the amount of hydrolyzable chlorine is desirably 1000 ppm or less.

The epoxy resin which satisfies these requirements is not particularly limited, but specific examples include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and 3,3'-diallylbisphenol A. Diglycidyl ether, polyglycidyl ether obtained by reaction of phenol novolak or cresol novolaks with epichlorohydrin, 1,
6-dihydroxynaphthalenediglycidyl ether,
There are N, N-diglycidylamino-1,3-glycidylphenyl ether and the like, and these may be used alone or in combination. Further, n-butyl glycidyl ether, glycidyl versatate, styrene oside, ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether,
Some are used as ordinary diluents for epoxy resins, such as butylphenyl glycidyl ether and the like, and these may be used as a mixture.

[0010] The bismaleimide compound represented by the general formula (1) used in the present invention is obtained by further dehydrating and ring-closing bismaleamic acid obtained by reacting a diamine with maleic anhydride. A prepolymer can be obtained by further reacting this bismaleimide with an aromatic diamine at a temperature of 200 ° C. or less. The bismaleimide and / or its prepolymer obtained in this way are excellent in heat resistance, and it is possible to use two or more kinds in combination.

The bismaleimide compound used in the present invention is not particularly limited as long as it is represented by the general formula (1).
(4,4'-diphenylmethane) bismaleimide, bis (3-ethyl-4-maleimidophenyl) methane, bis (3,5-dimethyl-4-maleimidophenyl) methane, bis (3,5-diethyl-4-maleimide) Phenyl) methane, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-tert-butyl -5-methyl-4- (4-
Maleimidophenoxy) phenyl] propane, 2,6-
Bis [2- (4-maleimidophenyl) propyl] benzene, etc., which may be used alone or in combination.

[0012] The liquid resin composition of the present invention comprises a filler of component (A), a liquid epoxy resin of component (B), and a component (C).
A bismaleimide compound and / or a prepolymer thereof,
It is composed of the curing agent of the component (D). The component (C) is preferably 4 to 35 parts by weight, more preferably 5 to 30 parts by weight, based on 100 parts by weight of the liquid epoxy of the component (B). More preferred. In order to improve the reflow resistance at 260 ° C., high heat resistance is required in order to suppress a decrease in physical properties at high temperatures, but when (C) is less than 4 parts by weight with respect to (B),
Effects such as an increase in Tg and an improvement in adhesive strength during heating are poor, and a viscosity exceeding 35 parts by weight significantly increases,
It is not preferable because the workability is deteriorated.

The curing agent used in the present invention can use phenolic compounds, organic acid anhydrides, amine compounds and the like, except that it is preferable that ionic impurities are extremely small, and the structure is not particularly limited. If necessary, compounds known as curing accelerators such as tertiary amines, imidazoles, triphenylphosphine, tetraphenylphosphine tetraphenylborate and the like can also be added. , A coupling agent and the like can also be used.

The production method of the present invention includes, for example, preliminarily mixing the components, kneading them using a three-roll mill, kneading the mixture, and defoaming under vacuum to obtain a resin paste. A semiconductor device using the liquid resin composition of the present invention as a die attach material is a highly reliable semiconductor device. The semiconductor device can be manufactured by a conventionally known method.

[0015]

The present invention will be specifically described below with reference to examples. The mixing ratio is shown in parts by weight. <Examples 1 to 3> Diglycidylbisphenol A (epoxy equivalent: 180, liquid at room temperature, liquid: Bis-A epoxy), cresyl glycidyl ether (epoxy equivalent: 185), bis (3-ethyl-5-methyl-)
4-maleimidophenyl) methane, phenol novolak (hydroxyl equivalent 104, softening point 80-90 ° C.), dicyandiamide, and 2-ethyl-4-methylimidazole in the proportions shown in Table 1 and kneaded with a three-roll mill. A liquid resin composition was obtained. After defoaming this liquid resin composition in a vacuum chamber at 2 mmHg for 30 minutes, various performances were evaluated by the following methods.

Viscosity: The viscosity was measured by using an E-type viscometer (3 ° cone) at 25 ° C. and 2.5 rpm to determine the viscosity. Tg: A test piece of 4 × 20 × 0.4 mm was prepared (curing conditions: 150 ° C., 60 minutes), measured by TMA in a tensile mode, and the inflection point of the TMA curve was defined as Tg. (Measurement length: 1
0 mm, temperature range: -100 ° C to 300 ° C, heating rate:
(10 ° C / min)

Adhesive strength: A silicon chip of 6 × 6 mm was mounted on a copper frame plated with 42 alloy, copper and silver using a liquid resin composition, and cured in an oven at 150 ° C. for 60 minutes. After curing, the die shear strength under heat at 260 ° C. was measured using an automatic mount strength measuring device (DAGE PC-2400). The cured sample is 8
Water absorption treatment was carried out at 5 ° C for 85% for 72 hours, and the hot die shear strength at 260 ° C was measured. Calculate the retention by moisture absorption and calculate 8
A case of 0% or more was regarded as a pass.

Reflowability: A 9 × 9 × 0.38 mm silicon die is mounted using a liquid resin composition on a 14 × 20 × 2.0 mm QFP frame (42 alloy and silver plated copper frame, die pad: 9.5 × 9.5 mm), 150 After curing at 60 ° C. for 60 minutes, the resultant was molded with a biphenyl-based sealing material (filler content: 88 wt%). The package was subjected to IR reflow three times after being subjected to a moisture absorption treatment under conditions of 85 ° C. and 85% RH for 168 hours. Reflow temperature is 2
60 ° C. or more for 10 seconds, the package after the reflow treatment is observed for peeling by a transmission type ultrasonic flaw detector,
Those having a peel area of 5% or more of the die pad area were regarded as defective, and the number of defective packages in 10 packages was used as an index of reflow property.

Example 4 A liquid was prepared in the same manner as in Example 1 except that kerimide B601 (manufactured by Ciba-Geigy) was used instead of bis (3-ethyl-5-methyl-4-maleimidophenyl) methane. A resin composition was prepared and evaluated.

<Comparative Examples 1 to 3> Liquid resin compositions were prepared in the proportions shown in Table 1 in the same manner as in Example 1, and evaluated in the same manner as in Example 1.

Table 1 shows the evaluation results.

[Table 1] In Comparative Example 3, since the viscosity of the liquid resin composition was extremely high and the wet spreading property was deteriorated, a good test piece and package could not be produced.

[0022]

The liquid resin composition of the present invention has excellent adhesion to a metal frame even at a high temperature of 260 ° C., so that even when the reflow temperature is 260 ° C., peeling and cracking do not occur during soldering. It is a reliable liquid resin composition for bonding semiconductor elements.

Continued on the front page F-term (reference) 4J002 CD041 CD051 CD061 CD131 DA079 DF019 DJ019 EJ008 EL026 EU027 EU118 EW018 FD019 FD148 GQ05 5F047 AA11 BA23 BA34 BB11 BB16

Claims (2)

[Claims] 1. A composition comprising a filler (A), a liquid epoxy resin (B), a bismaleimide compound represented by the general formula (1) and / or a prepolymer (C) thereof, and a curing agent (D). A liquid resin composition having an amount of 4 to 35 parts by weight based on 100 parts by weight of the liquid epoxy resin. Embedded image 2. A semiconductor device using the liquid resin composition according to claim 1 as a die attach material.