JP2005171170A - Resin paste for semiconductor and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin paste for semiconductor that has high thermal conductivity and is excellent in storage properties and adhesive strength. <P>SOLUTION: The resin paste for semiconductor is an electroconductive paste comprising (A) an epoxy resin, (B) an acid anhydride, (C) an imidazole compound, (D) a silver powder and (E) a solvent wherein the amount of the component (B) is 50-150 pts.wt., the amount of the component (C) is 0.1-10 pts.wt., the amount of the component (D) is 800-4,000 pts.wt., and the amount of the component (E) is 10-200 pts.wt., each based on 100 pts.wt. of the component (A). A semiconductor device is fabricated by using the resin paste. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin paste for semiconductor and a semiconductor device using the same.

  Recent advances in the electronics industry have evolved into transistors, ICs, LSIs, and super LSIs. The integration of circuits in these semiconductor devices has increased rapidly, enabling mass production, and semiconductors using these. With the spread of products, improvement in workability and cost reduction in mass production have become important problems. Conventionally, a semiconductor element is usually bonded to a conductor such as a metal frame by an Au-Si eutectic method and then sealed with a hermetic seal to obtain a semiconductor product. However, from the viewpoint of workability and cost during mass production, a resin sealing method has been developed and is now generalized. Along with this, a method using a solder material or a resin paste, that is, a mounting resin, has been taken up as an improvement of the Au-Si eutectic method in the mounting process.

  However, the solder method is disadvantageous in that it has low reliability and is likely to cause contamination of the electrode of the element, and its use is limited to power transistor and power IC elements that require high thermal conductivity. On the other hand, the mounting resin is superior in terms of workability and reliability as compared with the solder method, and its demand is rapidly increasing.

  In recent years, with the miniaturization of semiconductor devices, it has become important to increase the amount of heat generated from the devices and quickly release the heat to the surroundings, and the demand for resin pastes for semiconductors having high thermal conductivity has increased greatly.

Traditionally, thermosetting resins used in semiconductor resin pastes have low thermal conductivity, so the use of metals such as silver, copper, nickel, and aluminum as fillers and inorganic materials such as silica increases the thermal conductivity. This is described in, for example, Patent Documents 1 to 3, but is insufficient to satisfy the current requirements.
JP 2003-138244 A Japanese Patent Application Laid-Open No. 2002-241587 JP 2002-12738 A

  An object of the present invention is to provide a resin paste for semiconductors having high thermal conductivity and excellent storage stability and adhesive strength.

  The present invention is a conductive paste comprising (A) an epoxy resin, (B) an acid anhydride (C) imidazole compound, (D) silver powder, and (E) a solvent. B) is 50 to 150 parts by weight, component (C) is 0.1 to 10 parts by weight, component (D) is 800 to 4000 parts by weight, and component (E) is 10 to 200 parts by weight. This is a resin paste for semiconductors. In addition, the semiconductor device is manufactured using the above-described semiconductor resin paste.

  The resin paste for semiconductors of the present invention has high thermal conductivity, excellent storage stability and adhesive strength, and can be used for power transistor and power IC devices that require high thermal conductivity.

  The epoxy resin (A) used in the present invention is not particularly limited. For example, polyglycidyl ether, butanediol diglycidyl ether obtained by reaction of bisphenol A, bisphenol F, phenol novolac, cresol novolaks and epichlorohydrin, Aliphatic epoxy such as neopentyl glycol diglycidyl ether, heterocyclic epoxy such as diglycidyl hydantoin, alicyclic epoxy such as vinylcyclohexenedioxide, dicyclopentadiene dioxide, alicyclic diepoxy adipate, reactivity Diluent n-butyl glycidyl ether, versatic acid glycidyl ester, styrene oxide, ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl Ether, there is butylphenyl glycidyl ether monofunctional epoxy, which may be used singly or in combinations of two or more.

The acid anhydride (B) used in the present invention is used as a curing agent for epoxy resins.
Examples of the acid anhydride (B) used in the present invention include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, maleic anhydride, succinic anhydride, dodecynyl succinic anhydride, dichlorosuccinic anhydride, Methyl nadic acid anhydride, pyromellitic anhydride, methyl hexahydrophthalic anhydride, methylcyclohexene dicarboxylic acid anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, alkylstyrene- Examples include maleic anhydride copolymer, tetrabromophthalic anhydride, polyazeline acid anhydride, chlorendic acid anhydride, benzophenone tetracarboxylic anhydride, and the like. These may be used alone or in combination.

The compounding quantity of an acid anhydride (B) is 50-150 weight part with respect to 100 weight part of epoxy resins (A), More preferably, 60-130 weight part is used. If it is less than the lower limit, there is a problem that the adhesiveness and moisture resistance are inferior, and if it exceeds the upper limit, the storage stability is lowered.
The imidazole compound (C) used in the present invention is used as a catalyst for promoting the reaction between a curing agent or an epoxy resin and an acid anhydride. Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 2-phenyl-4. , 5-dihydroxy methyl imidazole, 2-C ₁₁ H ₂₃ - adds a generic imidazole or triazine and isocyanuric acid such as imidazole, to impart storage stability of 2,4-diamino-6- {2-methylimidazole - (1)}-Ethyl-S-triazine, or its isocyanate adduct, and the like can be used, and these can be used alone or in combination.

  The imidazole compound (C) is used in an amount of 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the epoxy resin (A). If it is less than the lower limit, accelerated curing is insufficient, and if it is more than the upper limit, curing is not accelerated so much, but the storability may be lowered.

  The silver powder (D) used in the present invention is used for imparting electrical conductivity and thermal conductivity, and the content of ionic impurities such as halogen ions and alkali metal ions is preferably 10 ppm or less. As the shape of the silver powder, a flake shape, a resin shape, a spherical shape, or the like is used. Although the particle size of the silver powder to be used varies depending on the required viscosity of the paste, it is usually preferable that the average particle size is 1 to 10 μm and the maximum particle size is about 50 μm. Moreover, a comparatively coarse silver powder and a fine silver powder can also be mixed and used, and various types of shapes may be appropriately mixed.

  The silver powder (D) is used in an amount of 800 to 4000 parts by weight, more preferably 1500 to 3000 parts by weight, based on 100 parts by weight of the epoxy resin (A). If it is less than the lower limit, there is a problem that the conductivity is inferior, and if it exceeds the upper limit, the viscosity increases.

The solvent (E) used in the present invention is used for adjusting the viscosity.
Examples of the solvent (E) used in the present invention include cellosolve acetate solvents such as methoxyethyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate and butyl cellosolve acetate, alcohol solvents such as ethyl alcohol, isopropyl alcohol and n-propyl alcohol, methoxy Cellosolve solvents such as alcohol and ethoxy alcohol, carbitol solvents such as methoxyethoxyethanol, diethoxyethanol and butoxyethoxyethanol, ester solvents such as ethyl acetate, butyl acetate, methyl methoxypropionate and ethyl lactate, methoxyethoxyethyl Carbitol acetate solvents such as acetate and diethoxyethyl acetate, ethylene glycol dimethyl ether, diethylene glycol dimethyl Ether solvents such as ether and tetrahydrofuran, aprotic amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone, lactone solvents such as γ-butyrolactone, toluene, Organic solvents such as aromatic hydrocarbon solvents such as xylene and aliphatic hydrocarbon solvents such as n-heptane, n-hexane, and n-octane.
The solvent (E) used in the present invention is used in an amount of 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, based on 100 parts by weight of the epoxy resin (A). If it is less than the lower limit, the viscosity is too high, and if it exceeds the upper limit, there is a problem that the viscosity is lowered.

In the resin paste in the present invention, additives such as a silane coupling agent, a titanate coupling agent, a pigment, a dye, an antifoaming agent, and a surfactant are used as long as the characteristics according to the use are not impaired as necessary. Can do.
As the production method of the present invention, for example, the respective components are premixed and kneaded using a three-roll or the like to obtain a paste and then dehydrated under vacuum.

The semiconductor device manufactured using the resin paste for semiconductors of the present invention has high thermal conductivity, excellent storage stability and adhesive strength, and is also used for power transistors and power ICs that require high thermal conductivity. It can be used.
A known method can be used as a method of manufacturing a semiconductor device using a resin paste for semiconductor.

The present invention will be specifically described with reference to examples. The blending ratio of each component is parts by weight.
<Examples 1-9 and Comparative Examples 1-8>
Each component of the composition shown in Table 1 and Table 2 was blended and kneaded with three rolls to obtain a resin paste. The resin paste was defoamed at 2 mmHg for 30 minutes in a vacuum chamber, and various performances were evaluated by the following methods. The evaluation results are shown in Tables 1 and 2.

<Used raw material components>
Liquid epoxy resin (A): RE-403S (Nippon Kayaku Co., Ltd., epoxy equivalent 165)
Acid anhydride (B): MH-700 (manufactured by Shin Nippon Rika Co., Ltd., acid anhydride equivalent 163.5)
Imidazole compound (C): 2MZ-A (manufactured by Shikoku Kasei Co., Ltd.)
・ Silver powder (D): Flakes with a particle size distribution of 0.1 to 50 μm and an average particle size of about 3 μm ・ Solvent (E): Butyl cellosolve acetate (BCSA)

<Evaluation method>
Viscosity and life: Using an E-type viscometer (3 ° cone), the value at 25 ° C. and 2.5 rpm was measured to obtain the viscosity. About the life, the viscosity after leaving the resin paste for 72 hours in a 25 degreeC thermostat was measured.
Adhesive strength: A 2 × 2 mm silicon chip was mounted on a silver frame using a paste, cured in an oven for 200/60 minutes, and the strength at room temperature was measured.
・ Thermal conductivity: The paste was prepared by ramp-up curing at room temperature to 200 ° C / 3 hours + 200 ° C / 2 hours, adjusted to a disk shape with a diameter of 1 cm and a thickness of 1 mm, and a laser flash method thermal conductivity meter Measured with

  In Examples 1 to 9, an excellent paste having high thermal conductivity and adhesive strength and high storage stability can be obtained, but Comparative Example 1 has low adhesive strength because there are few acid anhydride curing agents. Comparative Example 2 had a short life because of too much acid anhydride curing agent. Comparative Example 3 had low adhesive strength due to low imidazole, and Comparative Example 4 had short life due to too much imidazole. Comparative Example 5 had too little silver powder and low thermal conductivity, and Comparative Example 6 had high viscosity because of too much silver powder. Comparative Example 7 had a high viscosity due to too little solvent, and Comparative Example 8 had a low viscosity because of too much solvent.

  The resin paste for semiconductors of the present invention has high thermal conductivity, excellent storage stability and adhesive strength, and can be used for power transistor and power IC devices that require high thermal conductivity.

Claims (2)

(A) An epoxy resin, (B) an acid anhydride, (C) an imidazole compound, (D) silver powder, and (E) a conductive paste comprising a solvent. For semiconductor, wherein component (C) is 0.1 to 10 parts by weight, component (D) is 800 to 4000 parts by weight, and component (E) is 10 to 200 parts by weight Resin paste. A semiconductor device manufactured using the semiconductor resin paste according to claim 1.