JPH10195408A - Conductive resin paste composition and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition comprising a liquid aromatic group- containing epoxy resin, an epoxidized polybutadiene, an allylated phenolic resin and a conductive filler, capable of preventing the expansion of a package due to the steep expansion of water, when reflowed and soldered, and not generating reflow cracks. SOLUTION: This conductive resin paste composition comprises (A) an aromatic group-containing epoxy resin liquid at 20 deg.C (preferably a bisphenol F type epoxy resin), (B) an epoxidized polybutadiene [preferably a compound of formula I (R<1> , R<2> are each H, OH)], (C) an allylated phenolic resin preferably a resin of formula II [(m) is >=1]}, and (D) a conductive filler (preferably silver). Therein, the component B is added in an amount of 30-100 pts.wt. per 100 pts.wt. of the component A, and the component C is added in an amount of 10-30 pts.wt. per 100 pts.wt. of the total amount of the components A and B. The component D is also preferably added in an amount of 50-80 pts.wt. based on the amount of the composition. The average particle diameter of the component D is preferably <=10μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive resin paste composition suitable for bonding a semiconductor element such as an IC or an LSI to a lead frame, a glass epoxy substrate or the like, and a semiconductor device using the same.

[0002]

2. Description of the Related Art The mounting method of a semiconductor device has shifted from the conventional pin insertion method to the surface mounting method in terms of high-density mounting. Soldering is used, and the semiconductor device is 2
Because it is exposed to a high temperature of 00 ° C or higher,
In particular, there is a problem that a crack called a reflow crack occurs due to rapid vaporization and expansion of water contained in the adhesive layer or the sealing agent, and the reliability of the semiconductor device is greatly reduced.

[0003]

SUMMARY OF THE INVENTION The first aspect of the present invention provides a conductive resin paste composition which suppresses swelling of a package due to rapid vaporization and expansion of water during reflow soldering and does not generate reflow cracks. Things. The second aspect of the present invention provides a conductive resin paste composition which has an effect of reducing stress in addition to the effect of the first aspect of the present invention, and is excellent in an effect of suppressing reflow cracks. The third aspect of the present invention is to provide a semiconductor device which suppresses swelling of a package due to rapid vaporization and expansion of water during reflow soldering and does not generate reflow cracks.

[0004]

According to the present invention, (A) a temperature of 20 ° C.
The present invention relates to a conductive resin paste composition comprising an epoxy resin having an aromatic group which is liquid and having (B) an epoxidized polybutadiene, (C) an allylated phenol resin, and (D) a conductive filler. In the present invention, the epoxidized polybutadiene (B) preferably has the general formula (I)

Embedded image (Wherein R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group). Furthermore, the present invention relates to a semiconductor device formed by bonding a semiconductor element and a substrate using the conductive resin paste composition, and then sealing the substrate.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin (A) used in the present invention is a liquid epoxy resin at 20 ° C. (room temperature) and has an aromatic group. As the resin liquid at 20 ° C., a resin having a viscosity of 50 poise or less (20 ° C.) is preferable. Other epoxy resins have poor reflow resistance. As the epoxy resin, those having a low viscosity, specifically, those having a viscosity of 20 poise or less (20 ° C.) are preferable from the viewpoint that the diluent can be reduced. Further, from the viewpoint of curability, those having two or more epoxy groups in one molecule are preferable.

Examples of the epoxy resin having an aromatic group such as a benzene ring which is liquid at 20 ° C. include bisphenol A type epoxy resin (AER-X8501 (manufactured by Asahi Kasei Kogyo Co., Ltd.)) and bisphenol F type epoxy resin ( YDF-170 (manufactured by Toto Kasei Co., Ltd.), bisphenol AD type epoxy resin (R-1710 (manufactured by Mitsui Petrochemical Co., Ltd.)), aromatic glycidylamine type epoxy resin (ELM-100 (Sumitomo Chemical) Etc.), resorcinol-type epoxy resin (Denacol EX-201 (manufactured by Nagase Kasei Co., Ltd.), etc.), and the structural formula is the following general formula (II)

Embedded image (Where n is an integer of 0 to 5) (e.g., E-XL-24, E-XL-3L (all manufactured by Mitsui Toatsu Chemicals, Inc.)). These epoxy resins may be used in combination of two or more.

Of these, bisphenol F type epoxy resin and bisphenol AD type epoxy resin are preferable because of their low viscosity and excellent reflow resistance. Bisphenol F is a compound in which a group connecting two hydroxyphenyl groups is a methylene group, and bisphenol AD is a compound in which a group connecting two hydroxyphenyl groups is a 1,1-ethylene group.

The epoxidized polybutadiene (B) used in the present invention has a structure in which an epoxy group has been introduced into polybutadiene.
B3600, PB4700 (all manufactured by Daicel Chemical Industries, Ltd.), Nisseki polybutadiene E-1000-3.
5 (manufactured by Nippon Petrochemical Co., Ltd.), R-15EP1, R-
45EP1 (all manufactured by Idemitsu Petrochemical Co., Ltd.). These epoxidized polybutadienes may be used in appropriate combination.

These epoxidized polybutadienes (B)
In the formula, the following general formula (I)

Embedded image (However, R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group). Epoxidized polybutadiene represented by the following formula ( ¹ ) is preferred because of its high effect of reducing stress and excellent reflow resistance. The epoxidized polybutadiene of the formula, Epolead PB3600 (R1 and R2 are hydrogen atoms in the formula), Epolead PB4700 (R ¹ and R ² are hydroxyl groups in the formula) (all manufactured by Daicel Chemical Industries, Ltd.) Is mentioned. The amount of the epoxidized polybutadiene (B) can be adjusted according to the epoxy resin (A) 10 in view of reflow resistance and the like.
5 to 200 parts by weight, preferably 20 parts by weight,
-150 parts by weight is more preferable, and 30-100 parts by weight is particularly preferable.

The allylated phenolic resin (C) used in the present invention is a phenolic resin having an allyl group, and by using this, it is possible to improve the reflow resistance and the like. As the allylated phenol resin (C), general formula (III)

Embedded image (Where m is an integer of 1 or more) is preferable, and as a commercially available product, AL-VR-9300
(Manufactured by Mitsui Toatsu Chemicals, Inc.). In the general formula (III), m representing the number of repetitions is preferably an integer of 10 or less. The amount of the allylated phenol resin (C) is preferably 5 to 100 parts by weight, preferably 1 to 100 parts by weight, based on the total amount of the epoxy resin (A) and the epoxidized polybutadiene (B) from the viewpoint of reflow resistance and the like.
0 to 50 parts by weight is more preferable, and 10 to 30 parts by weight is particularly preferable.

The conductive filler (D) used in the present invention
The material is not particularly limited, and various materials may be used. Examples thereof include powders of metals such as gold, silver, copper, nickel, iron, aluminum, and stainless steel. Among these, silver having excellent conductivity and little ionic impurities is preferable. The shape of the conductive metal powder is flaky, dendritic,
There are a spherical shape and an irregular shape, and there is no particular limitation. The number average particle size is not particularly limited, but is preferably 50 μm or less, more preferably 10 μm or less from the viewpoint of conductivity and the like. Examples of such silver powder having an average particle diameter of 10 μm or less include, for example, TCG-1 (average particle diameter 2 μm, manufactured by Tokurika Chemical Laboratory Co., Ltd.) and TCG-7-6 (average particle diameter 3 μm, Tokuriki Chemical Co., Ltd.) Laboratories). Two or more types of silver powder may be used in appropriate combination. The average particle size can be measured by a master sizer (manufactured by Malvern) or the like. The compounding amount of the conductive filler (D) is preferably from 10 to 95 parts by weight based on the conductive resin paste composition from the viewpoints of adhesiveness, conductivity, and the like.
~ 80 parts by weight is more preferred.

Further, a curing accelerator can be added to the conductive resin paste composition of the present invention, if necessary. As a curing accelerator, dicyandiamide, an organic boron salt [EMZ · K, TPP (manufactured by Hokuko Chemical Co., Ltd.)
Tertiary amines and salts thereof [DBU, U-CAT1
02, 106, 830, 840, 5002 (all manufactured by Sun Apro Co., Ltd.), imidazoles (Cureazole 2P4MHZ, C17Z, 2PZ-O (all manufactured by Shikoku Chemicals Co., Ltd.)), acetylacetone metal salt (Al as metal) , Cu, Co, Ni, Zn, etc.). The curing accelerator added as needed may be used alone, or a plurality of curing accelerators may be used in appropriate combination. When these are used, the amount is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the epoxy resin (A).

A diluent may be added to the conductive resin paste composition according to the present invention, if necessary, in order to improve the workability in preparing the paste composition and the workability in applying the paste composition in use. it can. These diluents include:
Organic solvents having a relatively high boiling point, such as butyl cellosolve, carbitol, butyl cellosolve acetate, carbitol acetate ethylene glycol diethyl ether, α-terpineol, PGE (manufactured by Nippon Kayaku Co., Ltd.), PP-101
(Toto Kasei Co., Ltd.), ED-502, 503, 50
9 (manufactured by Asahi Denka Co., Ltd.), YED-122 (manufactured by Yuka Shell Epoxy Co., Ltd.), KBM-403, LS-797
0 (Shin-Etsu Chemical Co., Ltd.), TSL-8350, T
Reactive diluents having 1-2 epoxy groups in one molecule, such as SL-8355 and TSL-9905 (manufactured by Toshiba Silicone Co., Ltd.). From the viewpoint of reflow resistance, these are preferably small, and specifically, are preferably 10% by weight or less in the conductive resin paste composition.

The conductive resin paste composition according to the present invention may further contain, if necessary, an adhesion enhancer such as a silane coupling agent and a titanium coupling agent, a nonionic surfactant, a fluorine-based surfactant, and the like. A wetting improver, an antifoaming agent such as silicone oil, an ion trapping agent such as an inorganic ion exchanger, and the like can be appropriately added.

In order to produce the conductive resin paste of the present invention, the components (A), (B), (C) and (D), and a curing accelerator, a diluent, and various additives used as necessary. Add the agent or the like to the dispersion or dissolving device such as a stirrer, triturator, three rolls, planetary mixer, etc. or a combination thereof as appropriate, and heat and mix and dissolve as necessary. It may be pulverized, kneaded or dispersed to form a uniform paste.

In the present invention, a semiconductor device can be obtained by bonding a semiconductor element and a substrate using the conductive resin paste composition produced as described above, and then sealing it. In order to adhere a semiconductor element to a substrate such as a lead frame using the conductive resin paste composition of the present invention, first, a conductive resin paste composition was applied on a substrate by a dispensing method, a screen printing method, a stamping method, or the like. Thereafter, the semiconductor element can be press-bonded, and then heat-cured to, for example, 120 to 250 ° C. using a heating device such as an oven or a heat block. Further, after a wire bonding step, a completed semiconductor device can be obtained by sealing with a usual method, for example, using various sealing agents.

[0017]

Next, the present invention will be described in detail with reference to examples. 1) Preparation of phenol resin solution used in comparative example 1 part by weight of phenol novolak resin (manufactured by Meiwa Kasei Co., Ltd., trade name H-1, OH equivalent = 106) and alkylphenyl glycidyl ether (manufactured by Toto Kasei Co., Ltd.) as a diluent , Trade name PP-101, epoxy equivalent = 23
0) Heat 2 parts by weight to 100 ° C. and continue stirring for 1 hour,
A homogeneous phenolic resin solution was obtained. 2) Preparation of conductive resin paste composition Epoxy resin, epoxidized polybutadiene, allylated phenol resin which is liquid at 20 ° C. (room temperature) in the proportions shown in Table 1, and p-tertiary phenyl glycidyl ether (Toto Kasei) as a diluent Co., Ltd., PP-10
1), 2-phenyl-4-methyl-5 as a curing accelerator
-Hydroxyimidazole (2P, manufactured by Shikoku Chemicals Co., Ltd.)
4MHZ) and silver powder (TCG-7-6, manufactured by Tokurika Kagaku Kenkyusho Co., Ltd.) as a conductive filler, and kneaded using a three-roll mill, followed by defoaming at 5 Torr or less for 10 minutes. Then, a conductive resin paste composition was obtained.

3) Evaluation of Properties The properties (viscosity, adhesive strength, peel strength and reflow resistance) of this conductive resin paste composition were examined by the following methods. Table 1 shows the results. (1) Viscosity: The viscosity (Pa · s) at 25 ° C. was measured using an EHD type rotational viscometer (manufactured by Tokyo Keiki Co., Ltd.). (2) Adhesive strength: About 200 μg of the conductive resin paste composition was applied on a copper frame with Ag plating, and 2 mm was applied thereon.
A 2 mm Si chip (approximately 0.4 mm in thickness) was crimped, placed on a heat block set at 200 ° C., and heated for 60 seconds. Using an automatic adhesive strength tester (Micro tester, manufactured by Dege), the shear adhesive strength at room temperature (kg /
Chip) was measured. (3) Peel strength: about 3.2 mg of a conductive resin paste composition was applied on 42 alloy, and 8 mm × 8 mm of S
The i-chip (0.4 mm in thickness) was crimped, placed on a heat block set at 200 ° C., and heated for 60 seconds. This is an automatic adhesive device (manufactured internally by Hitachi Chemical Co., Ltd.)
Was used to measure the peel strength (kg / chip) at 240 ° C.

(4) Reflow Resistance Using the conductive resin paste compositions obtained in Examples and Comparative Examples, a 42 alloy lead frame and a silicon chip (chip size: 8 mm × 10 mm) were heated to 180 ° C. in 30 minutes. The mixture was cured and adhered under curing conditions of raising the temperature and curing at 180 ° C. for 6 hours. Thereafter, the package was sealed with an epoxy sealing material (CEL-4620, manufactured by Hitachi Chemical Co., Ltd.) to obtain a package for a solder reflow test. The package is QFP and has a size of 14 mm × 20 mm × 2 mm.
Temperature and humidity are 85 ° C and 85 ° C respectively.
% In a constant temperature / humidity chamber set for 96 hours. Thereafter, solder reflow was performed under reflow conditions of 240 ° C./10 seconds, and the number of external cracks generated in the package was observed with a microscope (magnification: 15 times). The number of cracked samples is shown for five samples.

[0020]

[Table 1]

From the results in Table 1, it can be seen that Comparative Example 1 in which the epoxidized polybutadiene and the allylated phenol resin were not used.
In this case, external cracks occur in all the packages, and in Comparative Examples 2 and 3, which do not use either one, external cracks occur in the packages at a high rate, which leads to a decrease in the reliability of the semiconductor device. On the other hand, in Examples 1 and 2, it was confirmed that the occurrence of external cracks in the package was suppressed, and a highly reliable package was obtained.

[0022]

According to the present invention, the conductive resin paste composition suppresses swelling of the package due to rapid vaporization and expansion of water during reflow soldering, and does not cause reflow cracks. The conductive resin paste composition according to the second aspect has the effects of the invention according to the first aspect, has an effect of reducing stress, and has an excellent effect of suppressing reflow cracks. In the semiconductor device according to the third aspect, the package is prevented from swelling due to rapid vaporization and expansion of water during reflow soldering, and reflow cracks do not occur. Therefore, the semiconductor device has high reliability.

Continued on the front page (72) Inventor Mitsuo Yamazaki 4-3-1-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Development Center, Semiconductor & LCD Materials Division, Hitachi Chemical Co., Ltd. (72) Inventor Chiaki Okada Higashimachi, Hitachi City, Ibaraki Prefecture 4-13-1 Hitachi Chemical Co., Ltd. Semiconductor & LCD Materials Division Development Center

Claims (3)

[Claims] 1. An epoxy resin having an aromatic group which is liquid at 20 ° C., (B) an epoxidized polybutadiene,
A conductive resin paste composition comprising (C) an allylated phenol resin and (D) a conductive filler. (B) The epoxidized polybutadiene is represented by the general formula (I): The conductive resin paste composition according to claim 1, wherein R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group. 3. A semiconductor device obtained by bonding a semiconductor element and a substrate using the conductive resin paste composition according to claim 1 and sealing the substrate.