JP3191243B2 - Method of manufacturing conductive resin paste and semiconductor device - Google Patents

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, and more particularly to a conductive resin paste suitable for bonding a semiconductor element to a support member and a method of manufacturing a semiconductor device using the same.

[0002]

2. Description of the Related Art Heretofore, as a method for joining a semiconductor element to a support member such as a lead frame, there are known (1) Au-Si eutectic method, (2) soldering method, and (3) resin paste method. . However, since the method (1) uses gold,
The cost is high and the working temperature is as high as about 400 ° C. The method (2) is cheaper than the method (1), but has a drawback that a gold thin film must be provided on the back surface of the semiconductor element, and the formation of the gold thin film is costly. The method (3) uses a resin paste obtained by mixing silver powder as a filler with a base resin of an epoxy resin or a polyimide resin, and is a cheaper method than the methods (1) and (2). At present, this resin paste method has become mainstream because of its advantages such as its ability to be used at a temperature of not more than ° C.

[0003]

However, the conventional resin paste is heated in an oven at 150 to 200 ° C. for 1 to 2 times.
There is a disadvantage that it is difficult to rationalize the semiconductor assembly process by in-line since it is necessary to heat and cure for a long time.
In addition, when curing within 1 minute is enabled, problems such as short shelf life, low bonding strength, particularly when heated to 200 to 350 ° C., and low generation of voids are also encountered. there were.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a conductive resin paste excellent in adhesive strength and workability when heated at 200 to 350 ° C. and a method of manufacturing a semiconductor device using the same. Is to provide.

[0005]

The present invention provides (A) a mixed epoxy resin comprising a phenol novolak type epoxy resin and an epi-bis type epoxy resin, (B) a phenol novolak resin and / or a phenol aralkyl resin, and (C) Organic borate salt, (D) a diluent containing at least one silane compound having one glycidyl group as a component, and (E) a conductive resin paste containing conductive metal powder, and a method for manufacturing a semiconductor device using the same About.

[0006] The mixed epoxy resin (A) used in the present invention is a mixture of a phenol novolak type epoxy resin and an epi-bis type epoxy resin. (Phenol novolak type epoxy resin / epi-bis type epoxy resin) is preferably in the range of 20/80 to 95/5.

A phenol novolak type epoxy resin is
A glycidyl ether of a phenol novolak resin or a cresol novolak resin, for example, DEN-438 (trade name, manufactured by Dow Chemical Company, YDC, manufactured by Toto Kasei Co., Ltd.)
N-701 and 702.

The epi-bis type epoxy resin is a condensate of bisphenol A, bisphenol AD, bisphenol F, bisphenol S, alkylated bisphenol A or halogenated bisphenol A with epichlorohydrin. Product name EP-
828, EP-1001, EP-1004, trade names YDF-170 and YDB-340 manufactured by Toto Kasei Co., Ltd., and trade name R-710 manufactured by Mitsui Petrochemical Co., Ltd.

The phenol novolak resin (B) used in the present invention is used as a main curing agent for an epoxy resin,
Examples include Meiwa Kasei's trade name H-1 and Hitachi Chemical's trade name Hp-607N. The phenol aralkyl resin used in the present invention is α, α′-dimethoxy-
A resin obtained by polycondensing p-xylene and phenol monomer with a Friedel-Crafts catalyst, and is used as a curing agent for the epoxy resin. Examples of commercially available products include XL-225 (trade name, manufactured by Mitsui Toatsu Chemicals, Inc., XYLOK-225, trade name, manufactured by Albright & Wilson Co., Ltd.). The amount of the phenol novolak resin and / or the phenol aralkyl resin (B) is determined based on the equivalent of the epoxy group of the mixed epoxy resin (A) from the viewpoint of curability and cured product properties.
Alternatively, the phenol aralkyl resin (B) has a hydroxyl group of 0.1.
It is preferable to use so as to be in the range of 6 to 1.5 equivalents.

The organic borate salt (C) used in the present invention
Is used as a curing accelerator, for example, tetraphenylphosphonium / tetraphenylborate salt (manufactured by Hokuko Chemical), 1,8-diazabicyclo (5,4,0) undecene-7.tetraphenylborate salt (manufactured by San Apro), 2-ethyl-4-methylimidazole tetraphenylborate salt (manufactured by Hokko Chemical Co., Ltd.). The amount of the organic borate salt (C) to be added is preferably 0.1 to 100 parts by weight of the total amount of the mixed epoxy resin (A) and the phenol novolak resin and / or the phenol aralkyl resin (B) from the viewpoint of curability and storage stability. It is preferable to use 1 to 30 parts by weight.

The diluent (D) used in the present invention contains a silane compound having one glycidyl group as one component. As this silane compound, for example, γ-glycidoxypropyltrimethoxysilane (KBM manufactured by Shin-Etsu Chemical Co., Ltd.)
-403), γ-glycidoxypropylmethyldimethoxysilane (TSL-8355 manufactured by Toshiba Silicone), γ
-Glycidoxypropylpentamethyldisiloxane (TSL-9905 manufactured by Toshiba Silicone), γ-glycidoxypropylmethyldiethoxysilane (manufactured by Chisso), γ-
Glycidoxypropyldimethylethoxysilane (manufactured by Chisso), (γ-glycidoxypropyl) -bis- (trimethylsiloxy) methylsilane (manufactured by Chisso), and the like. It is preferable that the content is 20 to 100% by weight based on the total amount of (D).

The diluents other than the silane compound include, for example, ethyl cellosolve, butyl cellosolve, cellosolve acetate, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, butyl carbitol, butyl carbitol acetate, α-terpineol and the like having a boiling point of 100. Organic solvent above ℃, phenyl glycidyl ether, cresyl glycidyl ether, p
-(T-butyl) phenyl glycidyl ether, p-
A reactive diluent having one or two epoxy groups in one molecule such as (sec-butyl) phenyl glycidyl ether and butanediol diglycidyl ether is used.

The diluent (D) is used for adjusting the viscosity of the conductive resin paste and improving the workability. The diluent (D) imparts a coupling effect by using the silane compound, and has a conductive property at 200 to 350 ° C. Adhesive strength of the cured resin paste when heated can be improved. The mixing amount of these diluents is 100 parts by weight based on the total amount of the mixed epoxy resin (A) and phenol novolak resin and / or phenol aralkyl resin (B) from the viewpoint of workability and stability of the conductive resin paste. It is preferably from 5 to 800 parts by weight.

The conductive metal powder (E) used in the present invention
Is for imparting conductivity to a conductive resin paste, and conductive powder such as silver, gold, copper, nickel, iron, and stainless steel is used. For example, TCG-1 (trade name, manufactured by Tokuri Chemical Co., Ltd.) as silver powder, TA-1 (trade name, manufactured by Tokuri Chemical Co., Ltd.) as gold powder, and CE- (trade name, Fukuda Metal Foil Powder) as copper powder.
115, Nickel powder is a product name of Type manufactured by Inco
-123, as iron powder, trade name Fe- manufactured by Fukuda Metal Foil Powder Co., Ltd.
As S-100 and stainless steel powder, there is SUS304L (trade name, manufactured by Fukuda Metal Foil Powder Co., Ltd.). Among them, silver is preferable from the viewpoints of oxidation resistance and conductivity. The conductive metal powder (E)
Is 100 to 1000 parts by weight based on 100 parts by weight of the total amount of the mixed epoxy resin (A) and the phenol novolak resin and / or the phenol aralkyl resin (B).
A range of parts by weight is preferred.

[0015] The conductive resin paste according to the present invention includes an adhesion enhancer such as a silane coupling agent and a titanium coupling agent, a wetting enhancer such as a nonionic surfactant and a fluorine surfactant, and silicone oil. Can be added as appropriate.

The conductive resin paste according to the present invention may be prepared, for example, by diluting a predetermined amount of a phenol novolak type epoxy resin, an epi-bis type epoxy resin and a phenol novolak resin and / or a phenol aralkyl resin into a diluent. Mix with a fixed amount, mix and stir with heating if necessary, dissolve by stirring, obtain a predetermined amount of varnish and a curing accelerator, diluent, conductive metal powder, and a coupling agent to be added as necessary And the like, are added in a lump or dividedly, and kneaded or dissolved by appropriately combining dispersers such as a stirrer, a grinder, a three-roller, and a ball mill.

A semiconductor device is obtained by joining a semiconductor element to a support member using the conductive resin paste according to the present invention. For example, a conductive resin paste according to the present invention is applied to a support member, and a semiconductor element is placed on the support member, pressed and heated to cure the paste, and the semiconductor element is joined to the support member to obtain a semiconductor device.

The conductive resin paste according to the present invention comprises I
It is suitable as a joining material for joining a semiconductor element such as a C or LSI to a support member such as a lead frame, a ceramic wiring board, or a glass epoxy wiring board, and joining a tantalum capacitor chip to a lead frame.

[0019]

The present invention will be described below with reference to examples. Examples 1 to 9 and Comparative Examples 1 to 4 DEN-438, EP-1001, H-1, XL-2 having the respective compositions shown in Table 1.
25, KBM-403 and butyl cellosolve in 100
A varnish is prepared by dissolving the mixture under heating at 400 ° C.
G-1 was kneaded with a grinder to prepare a conductive resin paste, and its properties were measured by the following methods.
It was shown to.

(1) Viscosity of conductive resin paste The viscosity at 25 ° C. was measured using an EHD type rotational viscometer manufactured by Tokyo Keiki. (2) Adhesive strength The obtained conductive resin paste was applied on a silver-plated copper lead frame, and then placed on a 2 mm × 2 mm silicon chip and pressed, and left on a heat block set at 250 ° C. for 30 seconds. And cured. The shear strength at room temperature and the shear strength at 350 ° C. of the cured sample were measured using a push-pull gauge (manufactured by Aiko Engineering Co., Ltd.). (3) Viscosity stability The viscosity of the conductive resin paste after leaving it to stand at 25 ° C. for 10 days was measured, and this viscosity was 0.8 to 1.2 of the initial viscosity.
Those within the doubled range were indicated by o, and those outside the range were indicated by x. The raw materials used in Table 1 are as follows. DEN-438: Phenol novolak type epoxy resin (trade name, manufactured by Dow Chemical Co., epoxy equivalent: 200) EP-1001: Epi-bis type epoxy resin (trade name, manufactured by Yuka Shell Epoxy Co., epoxy equivalent = 45)
0) XL-225: Phenol aralkyl resin (trade name, manufactured by Mitsui Toatsu Chemicals, hydroxyl equivalent: 185) H-1: Phenol novolak resin (trade name, manufactured by Meiwa Kasei Co., Ltd., hydroxyl equivalent: 106) KBM-403: Diluent (Shin-Etsu Chemical company's trade name, γ-glycidoxypropyltrimethoxysilane) butyl cellosolve: diluent (Kanto Chemical's trade name, reagent grade) TCG-1: conductive metal powder (Tokuriki Chemical's flake silver powder) TPP・ TPB: Curing accelerator (tetraphenylphosphonium / tetraphenylborate salt, manufactured by Hokko Chemical Co., Ltd.) 2E4MZ ・ TPB: Curing accelerator (2-ethyl-4-methylimidazole / tetraphenylborate salt, manufactured by Hokko Chemical Co.) DBU -TPB: curing accelerator (1,8-diazabicyclo (5,4,0) undecene-
7. Tetraphenylborate salt, manufactured by San Apro Co.) 2PZ-OK: curing accelerator (2-phenylimidazole / isocyanuric acid adduct, trade name, manufactured by Shikoku Chemicals)

[0021]

[Table 1]

From Table 1, it can be seen from Example 1 that a phenol novolak type epoxy resin and an epi-bis type epoxy resin were used in combination.
In Comparative Examples 3 to 3, the adhesive strength was higher than those in Comparative Examples 1 and 2 in which these epoxy resins were used alone, and in Comparative Example 3 in which the compound having one glycidyl group (KBM-403) was not added. In Comparative Example 4 in which the adhesive strength at a temperature of 0 ° C. was low and imidazoles were used as a curing accelerator,
Sufficient adhesive strength is obtained, but lacks viscosity stability.

[0023]

According to the conductive resin paste of the present invention,
Since a semiconductor element such as an IC or an LSI can be bonded to a support member for a lead frame, a ceramic wiring board, a glass epoxy board, or the like in a short time without lowering the adhesive strength when heated at 200 to 350 ° C. The joining process can be inlined, and the cost of the semiconductor device can be significantly reduced.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08K 5/5435 C08K 5/5435 C09J 163/00 C09J 163/00 H01L 21/52 H01L 21/52 E (72) Inventor: Kimihide Fujita Hitachi Chemical Industry Co., Ltd. Yamazaki Plant, Hitachi City, Ibaraki Pref. 4-1-1, Higashi-cho (72) Inventor Masao Kawasumi 4-3-1, Higashicho, Hitachi City, Ibaraki Prefecture, Hitachi Chemical Co., Ltd. Yamazaki Plant (56) References JP-A-1-189806 (JP, A) JP-A-59-172571 (JP, A) JP-A-64-60679 (JP, A) JP-B-63-4701 (JP, B2) Masaki Shinbo “Epoxy resin” Handbook ”(1st edition of the first edition issued on December 25, 1987) Nikkan Kogyo Shimbun, pages 19-21, 61-62 (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 63/00 -63/10 C08K 3/08 C08K 5/5435 C08G 59/38 C08G 59/62 C08G 59/68 C09J 163/00-163/10 H01L 21/52

Claims (2)

(57) [Claims] 1. A mixed epoxy resin comprising (A) a phenol novolak epoxy resin and an epi-bis epoxy resin, (B) a phenol novolak resin and / or a phenol aralkyl resin, (C) an organic borate salt, and (D) glycidyl. A conductive resin paste containing (E) a conductive metal powder and a diluent containing at least one silane compound having one group. 2. A method for manufacturing a semiconductor device, comprising joining a semiconductor element to a support member using the conductive resin paste according to claim 1.