JP2002009091A - Resin paste for semiconductor and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable resin paste for semiconductor which contains only a small quantity of chlorine ions in a material to be cured and can be cured at a high speed by an inline curing equipment. SOLUTION: The resin paste for semiconductor consists of epoxy resin, potential curing agent, 2-allyl-4,5-diphenylimidazole, and inorganic filler. The paste contains 5 to 10 pts.wt. of the 2-allyl-4,5-diphenylimidazole with respect to 100 pts.wt. of the epixy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin paste 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 The remarkable development of the electronics industry has evolved into transistors, ICs, LSIs, and super LSIs, and the degree of integration of circuits in these semiconductor devices has rapidly increased, and mass production has become possible. With the spread of used semiconductor products, improvement of workability and cost reduction in mass production have become important issues. Conventionally, it has been common practice to bond a semiconductor element to a conductor such as a metal frame by an Au-Si eutectic method, and then seal it with a hermetic seal to obtain a semiconductor product. However, from the viewpoint of workability and cost during mass production, a resin sealing method was developed,
It is now generalized. Along with this, a method using a resin paste, that is, a mounting resin, has been taken up as the improvement of the Au-Si eutectic method in the mounting process and has become mainstream.

Conventional mounting resin cures at 150-200 ° C
It was necessary to heat-treat in an oven for 1-2 hours. Recently, there has been an increasing demand for in-line curing within 3 minutes to streamline the semiconductor assembly process. As a one-pack type in-line technique, a method of using imidazole as a curing accelerator has conventionally been generally used, but there was a drawback that the chloride ion concentration of the cured product was increased. Chlorine ions in the cured product cause corrosion of aluminum wiring on an IC chip during long-term use, and may cause malfunction of an IC package.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin paste which can be cured in-line and which is fast and has a small amount of chlorine ions in the cured product.

[0005]

SUMMARY OF THE INVENTION The present invention provides a resin paste which is fast-curing capable of in-line curing and has a small amount of chlorine ions in the cured product.
It comprises (B) a latent curing agent, (C) 2 allyl-4,5 diphenylimidazole, and (D) an inorganic filler. Component (C) is 0.5 to 10 based on 100 parts by weight of component (A).
It is a resin paste for semiconductor which is a part by weight. Further, the present invention is a semiconductor device manufactured using the above-mentioned resin paste for a semiconductor.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin (A) used in the present invention comprises bisphenol A, bisphenol F, bisphenol AD, bisphenol S, phenol novolak, cresol novolaks, 4-aminophenol and 4-amino-m-cresol. Polyglycidyl ether obtained by reaction with epichlorohydrin, aliphatic epoxy such as butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, heterocyclic epoxy such as diglycidyl hydantoin, vinylcyclohexene dioxide, dicyclopentadiene dioxide, Cycloaliphatic epoxies such as alicyclic diepoxy-adipate, n-butyl glycidyl ether,
Versatic acid glycidyl ester, styrene oside, ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, butylphenyl glycidyl ether, etc.
It can be used in combination with one or more types. Further, those having a small molecular weight and being liquid at room temperature are preferable in view of workability at the time of compounding and viscosity after compounding.

The latent curing agent (B) used in the present invention is used as a curing agent for epoxy resins. It is a latent curing agent such as dicyandiamide. When a latent curing agent is used, the adhesive strength when heated becomes significantly higher than when cured with a phenol curing agent alone. Also, since the latent curing agent has a smaller equivalent weight than the phenolic curing agent, the viscosity is not so high when used in combination,
In addition, since it is latent, a paste having excellent storage stability can be obtained.

In the present invention, it has been found that by using diallyl-4,5 diphenylimidazole, it is possible to reduce the chloride ion in the cured product and achieve rapid curing. 2
The compounding amount of allyl-4,5 diphenylimidazole is preferably 0.5 to 10% by weight based on all epoxy resins. If it is less than 0.5% by weight, the adhesive strength at the time of heating is weak,
If it exceeds 10% by weight, the pot life is significantly shortened.

The inorganic filler (D) used in the present invention includes silver powder and silica filler. The inorganic filler preferably has an average particle size of 1 to 10 μm and a maximum particle size of about 500 μm. A mixture of a relatively coarse filler and a fine filler may be used, and various shapes may be appropriately mixed. The content of ionic impurities such as halogen ions and alkali metal ions is preferably 10 ppm or less.

[0010] In addition, an inorganic filler other than the present invention may be added to impart required properties.

In the resin paste of the present invention, a silane coupling agent, a titanate coupling agent, a pigment, a dye, a defoaming agent, a surfactant, a solvent and the like may be used as long as the properties according to the intended use are not impaired. Additives can be used. The production method of the present invention includes, for example, premixing each component, obtaining a paste using a three-roll or the like, and then defoaming under vacuum. A known method can be used for manufacturing a semiconductor device using a resin paste for a semiconductor.

[0012]

EXAMPLES The present invention will be specifically described with reference to Examples. The mixing ratio of each component is part by weight.

<Examples 1 to 3 and Comparative Examples 1 to 3> Each component having the composition shown in Table 1 and an inorganic filler were blended and kneaded with a three-roll mill to obtain a resin paste. After defoaming the resin paste at 2 mmHg for 30 minutes in a vacuum chamber, various performances were evaluated by the following methods. Table 1 shows the evaluation results.

<Raw materials used> Epoxy resin (A) Mixed epoxy resin (EP) consisting of 70 parts of bisphenol A type epoxy resin (viscosity 9000 mPa · s, epoxy equivalent 185) and 30 parts of phenyl glycidyl ether • Latent curing agent (B) Dicyandiamide (DDA)-Imidazole compound (C) 2-allyl-4,5-diphenylimidazole (IMZ-
A) 2-Methyl-imidazole (IMZ-B)-Inorganic filler (D) Silver powder, flakes having a particle size of 0.1 to 50 m and an average particle size of 3 m

<Evaluation method> Viscosity: 25 ° C. using an E-type viscometer (3 ° cone);
The value at 5 rpm was measured and defined as viscosity. Adhesive strength: A 2 × 2 mm silicon chip was mounted on a copper frame using a paste and cured on a hot plate at 200 ° C. for 60 seconds. After curing, use a mount strength measurement device.
The adhesive strength under heat at 250 ° C. and 250 ° C. was measured. Pot life: The number of days until the viscosity when the resin paste was allowed to stand in a thermostat at 25 ° C. increased to 1.2 times or more the initial viscosity was measured. Chlorine ion amount: The paste was cured at 200 ° C. for 60 minutes and then pulverized. 40 g of pure water was added to 2 g of the pulverized product, and hot water extraction was performed at 125 ° C. for 20 hours, and the chloride ion concentration was measured from the obtained extract by ion chromatography.

[0016]

[Table 1]

[0017]

[Table 2]

In Examples 1 to 3, a resin paste having a high adhesive strength, a long pot life, and a small amount of chlorine ions was obtained. In Comparative Example 1, however, the amount of IMZ-A added was small and the adhesive strength at heating was low. Was. In Comparative Example 2, the pot life was shortened because the amount of IMZ-A added was too large. In Comparative Example 3, the chloride ion concentration was high because IMZ-B was used.

[0019]

The resin paste for semiconductors of the present invention can be rapidly cured in an in-line device, and a highly reliable semiconductor device having a small amount of chlorine ions in a cured product can be obtained.

Claims (2)

[Claims] 1. An epoxy resin, (B) a latent curing agent, (C) 2 allyl-4,5 diphenylimidazole,
(D) A resin paste for a semiconductor, comprising an inorganic filler, wherein the component (C) is 0.5 to 10 parts by weight based on 100 parts by weight of the component (A). 2. A semiconductor device manufactured using the resin paste for a semiconductor according to claim 1.