JP2002064111A - Resin paste for semiconductor and semiconductor device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide resin paste where the modulus of elasticity of a curing object is small, the warpage of a semiconductor device after curing is small, and bonding strength in heating of the bonding layer between the semiconductor element and a metal frame is not reduced. SOLUTION: This resin paste for a semiconductor is shown by a general expression (1) where (n) is an integer being equal to or more than 1, and comprises long-chain alicyclic epoxy resin having at least four carbon atoms between cyclohexanoxide groups, acetyleacetonate, a phenol compound, a low- stress agent, and silver powder. The semiconductor device is manufactured by the resin paste for a semiconductor.

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, and a semiconductor device.

[0002]

2. Description of the Related Art Recent remarkable developments in the electronics industry have evolved into transistors, ICs, LSIs, and ultra-LSIs. These semiconductor devices have rapidly increased the degree of circuit integration and have enabled mass production. With the widespread use of semiconductor products using semiconductor devices, improvements in workability and cost reduction in mass production have become important issues. Conventionally, it has been common practice to join 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 device. However, from the viewpoints of workability during mass production, cost, and the like, a resin sealing method has been developed and is now generally used. Accordingly, a method using a solder material or a resin paste has been adopted as an improvement of the Au-Si eutectic method in the mounting step.

However, the solder method has drawbacks such as low reliability and easy contamination of the electrodes of the semiconductor element. Power transistors which require high thermal conductivity are disadvantageous.
It is used only for power IC elements. On the other hand, resin paste is superior in workability, reliability, etc. as compared with the solder method, and its demand is rapidly increasing. However, in general, resin paste has a large elastic modulus of a cured product, resulting in warpage. And the damage to the semiconductor element tends to increase, and a resin paste having a small elastic modulus after curing is required. With the diversification of semiconductor elements, there are various sizes of semiconductor elements. Particularly, in the case of large semiconductor elements, if the elasticity of the cured product of the resin paste is large, the semiconductor paste may be broken. Conventionally, a technique for reducing the elastic modulus by adding a low-stress agent such as a rubber-based material and reducing warpage is known. There is a possibility that the viscosity may increase and the adhesive strength at the time of heating may decrease, and a resin paste containing a resin capable of imparting a low elastic modulus has been required.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a cured product of a resin paste has a low modulus of elasticity, and when a semiconductor element is bonded to a metal frame or the like using this, the warpage of the semiconductor element is small, It is to provide a resin paste whose strength does not decrease.

[0005]

The present invention comprises (A) a long-chain alicyclic epoxy resin represented by the general formula (1), (B) a metal complex represented by the general formula (2), and (C) phenol. The compound, (D) a low stress agent and (E) silver powder are essential components, and the component (B) is added in an amount of 0.2 to 100 parts by weight of the component (A).
２０20 parts by weight, component (C) 3-20 parts by weight, component (D) 5-30 parts by weight, component (E) 150-800
A resin paste for a semiconductor characterized by being a weight part, and a semiconductor device manufactured by using the resin paste.

Embedded image (N is an integer of 1 or more)

[0006]

Embedded image (M is an I-III valent metal atom)

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The general formula (1) used in the present invention
The long-chain alicyclic epoxy resin represented by has four or more carbon atoms between the cyclohexene oxide groups,
By using the resin paste, the elastic modulus of the cured resin paste is reduced, and as a result, the warpage of the semiconductor element is reduced, and further, the adhesive strength at the time of heat of the adhesive layer between the semiconductor element and the metal frame is not reduced. Have. It can be used in combination with other epoxy resins as long as the properties of the long-chain alicyclic epoxy resin represented by the general formula (1) are not impaired. The epoxy resin to be used in combination is not particularly limited. For example, styrene oxide, vinylcyclohexene dioxide, dicyclopentadiene dioxide, alicyclic diepoxy-adipate, or bisphenol A, bisphenol F, phenol novolak resin, cresol novolak Polyglycidyl ether obtained by reaction of resin and epichlorohydrin, aliphatic epoxy such as butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, heterocyclic epoxy such as diglycidyl hydantoin,
Celloxide 2021 (Daicel Chemical Industries, Ltd.) and the like. In order to maximize the characteristics of the long-chain alicyclic epoxy resin represented by the general formula (1), the total amount of the epoxy resin is preferably 25% by weight or more. These may be used alone or as a mixture. The long-chain alicyclic epoxy resin represented by the general formula (1) is commercially available from Daicel Chemical Industries, Ltd. as celloxide (2081, 2083).

The metal complex (B) represented by the general formula (2) used in the present invention is acetylacetonate, which acts as a curing accelerator. Specifically, nickel (I) acetylacetonate, aluminum acetylacetonate, beryllium acetylacetonate, chromium (III) acetylacetonate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, copper (II) ) Acetylacetonate, indium (III) acetylacetonate, iron (II) acetylacetonate, lithium (I) acetylacetonate, magnesium (II) acetylacetonate, manganese (II)
Examples include acetylacetonate and zinc (II) acetylacetonate. Aluminum acetylacetonate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, zinc (I
I) acetylacetonate and the like. The amount of the metal complex (B) represented by the general formula (2) is preferably 0.2 to 20% by weight based on 100 parts by weight of the component (A). If it is less than 0.2% by weight, the effect of accelerating curing is insufficient, and 20% by weight.
Exceeding the viscosity is not preferable because the viscosity of the resin paste may increase despite the fact that the curing acceleration effect is not so large.

[0009] The phenolic compound (C) used in the present invention acts as a curing agent for the epoxy resin and improves the adhesiveness and moisture resistance. The phenol compound (C) preferably has two or more active hydrogen groups per molecule which react with an epoxy group and contribute to crosslinking. For example, bisphenol A, bisphenol F, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, dihydroxydiphenyl ether, dihydroxybenzophenone, o-hydroxyphenol, m-hydroxyphenol, p-hydroxyphenol, biphenol, tetramethylbiphenol, ethylidenebisphenol, methylethylidenebis (methylphenol), cyclidene hexylidene An initial condensate obtained by reacting bisphenol or a phenol such as phenol, cresol, xylenol and formaldehyde with an acid catalyst; And acrolein, an initial condensate obtained by reacting a polyfunctional aldehyde such as glyoxal under an acid catalyst, or an initial condensate obtained by reacting a phenol such as resorcinol, catechol and hydroquinone with formaldehyde aldehyde under an acid catalyst. Condensates and the like may be mentioned, and these may be used alone or as a mixture. The blending amount of the phenol compound (C) is preferably 3 to 20% by weight based on 100 parts by weight of the component (A) from the viewpoint of adhesiveness and moisture resistance. If it is less than 3% by weight, the curability is insufficient, and sufficient adhesive strength under heat cannot be obtained. If it exceeds 20% by weight, the viscosity of the resin paste may increase, which is not preferable.

[0010] The low stress agent (D) used in the present invention has an effect of reducing the elastic modulus of the cured resin paste,
Although not particularly limited, for example, polyisoprene, polybutadiene, 1,2-polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polychloroprene, poly (oxypropylene), poly (oxytetramethylene) glycol, polyolefin glycol,
Examples thereof include poly-ε-caprolactone, silicone rubber, polysulfide rubber, and fluoro rubber. The amount of the low stress agent (D) is 5 parts per 100 parts by weight of the component (A).
The content is preferably from 30 to 30% by weight from the viewpoint of lowering the elastic modulus. If it is less than 5% by weight, the modulus of elasticity increases,
If the amount exceeds the weight percent, the viscosity of the resin paste increases extremely,
Further, the adhesive strength upon heating is undesirably reduced.

The silver powder (E) used in the present invention imparts conductivity, and the content of ionic impurities such as halogen ions and alkali metal ions is preferably 10 ppm or less. The shape of the silver powder may be flakes, dendrites, spheres, or the like. The particle size of the silver powder to be used varies depending on the viscosity of the required resin paste, but usually the average particle size is preferably 2 to 10 μm, and the maximum particle size is preferably about 50 μm. In addition, a mixture of a relatively coarse silver powder and a fine silver powder may be used, and various shapes may be appropriately mixed and used. The amount of the silver powder (E) is preferably 150 to 800 parts by weight based on 100 parts by weight of the component (A). If it is less than 150 parts by weight, the conductivity is insufficient, and if it exceeds 800 parts by weight, the viscosity of the resin paste may increase, which is not preferable.

In the resin paste of the present invention, if necessary, additives such as a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a pigment, a dye, a defoaming agent, a surfactant, and a solvent can be used. . As a method for producing the resin paste in the present invention, for example, there is a method in which each component is premixed, a paste is obtained using a three-roll or the like, and the paste is defoamed under vacuum.

The semiconductor device manufactured by using the semiconductor resin paste of the present invention has a low stress and therefore has little damage to the semiconductor element and is highly reliable. A known method can be used for manufacturing a semiconductor device using a resin paste for a semiconductor.

[0014]

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 5 and Comparative Examples 1 to 7 The components shown in Tables 1 and 2 were mixed with silver powder 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 material components used: A long-chain alicyclic epoxy resin represented by the general formula (1):
Celloxide 2081 (manufactured by Daicel Chemical Industries, Ltd.)
Viscosity 10 poise / 40 ° C., epoxy equivalent 200) Bisphenol F type epoxy resin: (viscosity 34 poise)
/ 25 ° C, epoxy equivalent 166)

A metal complex in which M in the general formula (2) is aluminum: aluminum acetylacetonate (manufactured by Kawaken Fine Chemical Co., Ltd.) bisphenol S butadiene-acrylonitrile rubber containing a terminal carboxyl group: CTBN-1008- SP (Ube Industries, Ltd.)
(Hereinafter referred to as CTBN) ・ Compound (elastomer) obtained by adding propylene oxide to bisphenol A: BP-5P (manufactured by Sanyo Chemical Industries, Ltd.) ・ Silver powder: 0.1 to 50 μm in average particle diameter 3μm flakes

Evaluation method Viscosity: 25 ° C., 2.5 using an E-type viscometer (3 ° cone)
The value at rpm was measured and defined as viscosity. Adhesive strength: Using a resin paste, a 2 × 2 mm silicon chip was mounted on a silver frame and placed in an oven for 200 hours.
Cured at 60 ° C. for 60 minutes. After curing, 85 ° C, relative humidity 85
% In a constant temperature bath for 72 hours, and the adhesive strength under heat at 250 ° C. before and after moisture absorption was measured using a mount strength measuring device. Warpage: A silicon chip of 6 × 15 mm was mounted on a silver frame using a resin paste having a thickness of 30 μm, and cured in an oven at 200 ° C. for 60 minutes. After curing, the warpage of the chip was measured. Elastic modulus: 1x1 cured in oven at 200 ° C for 60 minutes
The tensile strength of a 3 cm strip sample at room temperature was measured to determine the elastic modulus.

[0018]

[Table 1]

[0019]

[Table 2]

In Examples 1 to 5, excellent resin pastes having high adhesive strength when heated, low elastic modulus and small warpage were obtained.
In Comparative Example 1, since only the bisphenol F type epoxy resin was used, the warpage and the elastic modulus were high. In Comparative Example 2, warpage and elasticity were high due to a small amount of CTBN, and in Comparative Example 3, the viscosity was high and the hot adhesive strength was low due to a large amount of CTBN. In Comparative Example 4, since the amount of aluminum cetyl acetonate was small, the adhesive strength under heat was low.
Had a high viscosity because of the large amount of aluminum cetyl acetonate. In Comparative Example 6, the adhesive strength at the time of heating was low because the amount of bisphenol S was small, and in Comparative Example 7, the viscosity was high because the amount of bisphenol S was large.

[0021]

The semiconductor device manufactured by using the semiconductor resin paste of the present invention has a low elastic modulus and a small warpage, so that the semiconductor element is less damaged and has excellent reliability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 163/00 C09J 163/00 // (C08L 63/00 (C08L 63/00 21:00) 21:00 ) F-term (Reference) 4J002 AC032 AC042 AC062 AC072 AC082 AC092 BB202 BD122 CC033 CD021 CF192 CH022 CN022 CP032 DA078 EE046 EJ027 EJ037 FA018 FA088 FD118 FD143 FD147 FD156 FD202 GJ01 GQ04 FA03 DA044J05CA08 DA142 DC092 EC261 ED002 EJ022 EK032 HA066 HD41 KA32 LA06 LA09 NA20 5F047 BA34 BA35 BA53 BB11 BB16

Claims (2)

[Claims] (A) a long-chain alicyclic epoxy resin represented by the general formula (1), (B) a metal complex represented by the general formula (2), (C) a phenol compound, and (D) a low-stress agent. And (E) silver powder as an essential component, and for 100 parts by weight of component (A), 0.2 to 20 parts by weight of component (B), 3 to 20 parts by weight of component (C), and component (D). A resin paste for a semiconductor, comprising 5 to 30 parts by weight and 150 to 800 parts by weight of the component (E). Embedded image (N is an integer of 1 or more) (M is an I-III valent metal atom) 2. A semiconductor device manufactured by using the resin paste for a semiconductor according to claim 1.