JPH0697324A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the cracks of sealing resin and the separation on the boundary between the sealing resin and a semiconductor element by using thermohardening resin in which polymaleimide compounds are contained as a main substance for a sealing resin composition. CONSTITUTION:Thermohardening resin in which polymaleimide compounds are contained as a main substance is used to obtain the characteristic of sealing resin component that a bending strength is not less than 4kg/mm<2> at 240 deg.C. For the polymaleimide compounds, a compound having not less than two maleimide radicals in one molecule and shown with a formula is used. Also, in order to obtain the characteristic that an elastic modulus for bending is 1400kg/mm<2> at 25 deg.C, polyorganosiloxane compounds are used to uniformly diffusing them into a sealing resin composition. Inorganic filler, silicone oil, fatty acid and the like are mixed and the sealing resin is composed of the mixture and the like. Thereby, the generation of cracks and separation due to the thermal stress at the time of mounting may be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed semiconductor device, and more particularly to a surface-mounted resin-sealed semiconductor device to which a reflow or flow soldering method is applied when mounting on a printed wiring board. is there.

[0002]

2. Description of the Related Art Conventionally, a resin-encapsulated semiconductor device has mainly been an insertion mounting type semiconductor device represented by a dual in-line package (hereinafter referred to as a DIP). There is a rapid transition to surface mounting type semiconductor devices such as a package (hereinafter referred to as SOP), a small outline J-lead package (hereinafter referred to as SOJ), and a quad flat package (hereinafter referred to as QFP).

In the conventional insertion-mounting type semiconductor device, only the lead portion of the semiconductor device is dipped in solder when it is mounted on a printed wiring board, but in the surface-mounting type semiconductor device, it is mounted by whole heating such as reflow or flow method. It In such a total heating mounting method, the entire semiconductor device is
Since the semiconductor device is exposed to a high temperature of 0 ° C. or more, moisture that has been absorbed particularly during storage of the semiconductor device causes a rapid thermal stress, which causes cracks in the encapsulating resin portion or the semiconductor element and the encapsulating resin. Separation may occur at the interface of the semiconductor device, which is a fatal problem for the reliability of the semiconductor device.

[0004]

With respect to the above problems,
The glass transition temperature of the sealing resin mainly composed of epoxy resin, which has been the mainstream in the past, is much lower than the soldering temperature, and it is not possible to obtain sufficient strength to overcome the thermal stress during mounting. In recent years, there has been a tendency for the inorganic filler to be highly filled in order to reduce the coefficient of thermal expansion of the encapsulating resin, which causes the elastic modulus of the encapsulating resin to increase, increasing residual stress during molding, and increasing the mounting time. It is a factor that promotes the occurrence of peeling at the interface between the semiconductor element and the sealing resin due to the thermal stress.

An object of the present invention is to prevent the sealing resin from cracking and peeling from the interface between the sealing resin and the semiconductor element during mounting by increasing the strength of the sealing resin at high temperature and decreasing the elastic modulus. , To provide a highly reliable resin-encapsulated semiconductor device.

[0006]

In order to achieve the above object, the present invention is characterized in that a semiconductor element is sealed with a resin composition having the following characteristics (A) and (B). . (A) The flexural strength of the cured product of the resin composition at 240 ° C. is 4 kg / mm ² or more. (B) The flexural modulus at 25 ° C. of the cured product of the resin composition is 1400 Kg / mm ² or less.

Generally, the sealing resin is mainly composed of a thermosetting resin such as an epoxy resin and an inorganic filler such as silica, and is used in manufacturing the resin-sealed semiconductor device of the present invention. The encapsulating resin composition also has a thermosetting resin and an inorganic filler as main components, but in order to satisfy the characteristics of (A) of the present invention, a thermosetting resin mainly containing a polymaleimide compound is used. It is necessary to use a resin. As the polymaleimide compound, any compound having two or more maleimide groups in one molecule can be used.
For example, general formula (1) [Chemical formula 1];

[0008]

[Chemical 1] (In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X ₁ represents —CH ₂ —, —CO—, —SO ₂ —, —S—, —O— or a cycloalkyl group. m represents 0 or 1.), more specifically, N, N '-(1,3-phenylene) bismaleimide, N, N'-[1,
3- (2-Methylphenylene)] bismaleimide, N, N '-(1,4-
Phenylene) bismaleimide, bis (4-maleimidophenyl) methane, bis (3-methyl-4-maleimidophenyl) methane, bis (4-maleimidophenyl) ether,
Examples thereof include bis (4-maleimidophenyl) sulfone, bis (4-maleimidophenyl) sulfide, bis (4-maleimidophenyl) ketone, and 1,4-bis (4-maleimidophenyl) cyclohexane. In addition, general formula (2) [Chemical formula 2];

[0009]

[Chemical 2] (Wherein, X ₂ represents a divalent organic group having at least one substituted or unsubstituted aromatic ring), more specifically, 1,3-bis (4-maleimide) Phenoxy) benzene, 1,3-bis (3-maleimidophenoxy) benzene, bis [4- (3-maleimidophenoxy)
Phenyl] methane, bis [4- (4-maleimidophenoxy)
Phenyl] methane, 1,1-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (3 -Maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (4-maleimidophenoxy) phenyl] ethane, 2,2-bis [4- (3-maleimidophenoxy) phenyl] propane, 2,2-bis [ Four
-(4-maleimidophenoxy) phenyl] propane, 2,2-
Bis [4- (3-maleimidophenoxy) phenyl] butane,
2,2-bis [4- (4-maleimidophenoxy) phenyl] butane, 2,2-bis [4- (3-maleimidophenoxy) phenyl]-
1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-
Maleimidophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4,4′-bis (3-maleimidophenoxy) biphenyl, 4,4′-bis (4-maleimidophenoxy) biphenyl, Bis [4- (3-maleimidophenoxy) phenyl] ketone, Bis [4- (4-maleimidophenoxy) phenyl] ketone, Bis [4- (3-maleimidophenoxy) phenyl] sulfide, Bis [4- (4-maleimide) Phenoxy) phenyl] sulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfoxide, bis [4- (4-maleimidophenoxy) phenyl] sulfoxide, bis [4- (3-maleimidophenoxy) phenyl] sulfone, bis [bis 4- (4-
Maleimidophenoxy) phenyl] sulfone, bis [4-
(3-Maleimidophenoxy) phenyl] ether, bis
[4- (4-maleimidophenoxy) phenyl] ether, 1,
4-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4- Screw
[4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy)-
α, α-Dimethylbenzyl] benzene, 1,4-bis [4- (4-
Maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1 , 4-Bis [4- (3-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy) -3,5-dimethyl- α, α
-Dimethylbenzyl] benzene and the like. Furthermore,
General formula (3) [Chemical formula 3];

[0010]

[Chemical 3] (Wherein, X ₃ represents a methylene group or a p-xylylene group, n represents a number of 0 to 5 not including 0), and more specifically, such a polymaleimide compound The maleimide compound is a polymaleimide compound obtained by subjecting polyamine, which is a reaction product of aniline and formaldehyde, or α, α′-dichloro-p-xylene, and maleic anhydride to a condensation / dehydration reaction under an acidic catalyst. . These bismaleimide compounds or polymaleimide compounds may be used alone or in combination of two or more.

Although the polymaleimide compound has excellent heat resistance, it has a problem in flexibility and moldability when used alone. Therefore, it may be used in combination with other resin to balance the moldability and heat resistance. it can. From this point of view, the combined use with an epoxy resin is particularly preferable, and any epoxy resin having at least two epoxy groups in one molecule can be used. These are illustrated below.
Phenols such as phenol, cresol, resorcinol, naphthol and formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde,
Novolak type epoxy resin derived from novolak resin, which is a reaction product with aldehydes such as gluoxal and alkanedials, and aralkyl type derived from aralkyl resin, which is a reaction product of the above phenols and aralkyl alcohol derivatives Epoxy resin is preferable in terms of heat resistance and electric characteristics.

In addition, epoxy resins derived from compounds having two or more active hydrogens in one molecule, such as bisphenol A, bisphenol F, resorcin, bishydroxydiphenyl ether, 4,4'-bishydroxy.
Polyhydric phenols such as -3,3 ', 5,5'-tetramethylbiphenyl, tetrabromobisphenol A, dihydroxynaphthalene; ethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diethylene glycol, polypropylene glycol, etc. Obtained by reacting polyamines such as ethylenediamine, aniline and bis (4-aminophenyl) methane with polycarboxylic acids such as adipic acid, phthalic acid and isophthalic acid and epichlorohydrin or 2-methylepichlorohydrin Examples thereof include epoxy resins, and one or more of these epoxy resins are used.

As the curing agent for the epoxy resin, known compounds such as phenols, amines and acid anhydrides can be used, but phenol resins are most preferably used. For example, novolak resin, which is a reaction product of phenols such as phenol, cresol, resorcinol, and naphthol with aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, gluoxal, alkanedial, and the above phenols and aralkyl alcohol derivatives. Examples thereof include aralkyl resins which are reaction products of, and one or more of these are used.

In the encapsulating resin composition of the present invention, when an epoxy resin is used in combination with the polymaleimide compound, the total amount of the epoxy resin and the curing agent is 10 to 500 parts by weight with respect to 100 parts by weight of the polymaleimide compound. Preferably 25-300
Parts by weight. Also, the ratio of epoxy resin and curing agent is
The curing agent is equivalent to the epoxy group of the epoxy resin.
It is in the range of 0.1 to 10, preferably in the range of 0.5 to 2.0.

In order to satisfy the characteristic (B) of the present invention, it is necessary to use a polyorganosiloxane compound. In particular, it is preferable to uniformly disperse the rubber-like polyorganosiloxane compound as particles in the sealing resin composition. Such a rubber-like polyorganosiloxane compound particle is a liquid having a low molecular weight before being introduced into the encapsulating resin composition, and is uniformly dispersed at the time of introduction, and then cured by an addition reaction to be cured into a rubber-like polyorganosiloxane compound. A substance to be particles or a polyorganosiloxane compound having a rubber-like particle form before introduction, which is uniformly dispersed in the encapsulating resin composition.

As a concrete example, the former is a liquid vinyl-modified polyorganosiloxane compound having a vinyl group in the molecule, a liquid hydrogen-modified polyorganosiloxane compound having an active hydrogen in the molecule, and a platinum catalyst as a curing catalyst. And becomes a rubber-like polymer by adding active hydrogen to the vinyl group. A commercially available example is SE1 from Toray Dow Corning Silicone Co., Ltd.
821, Shin-Etsu Chemical Co., Ltd. KE1204, Toshiba Silicone Co., Ltd. TSE3032, etc.

As a method for introducing these polyorganosiloxane compounds as particles into the encapsulating resin composition, all or part of the thermosetting resin mainly composed of the polymaleimide compound which has been heated and melted is stirred. Then, a mixture of a vinyl-modified polyorganosiloxane compound, a hydrogen-modified polyorganosiloxane compound and a platinum catalyst is introduced and reacted at 50 to 150 ° C. for 5 minutes to 6 hours,
Disperse uniformly as rubbery particles. By melt-mixing all or part of the thermosetting resin mainly composed of the polymaleimide compound in which the rubber-like particles are dispersed together with other raw materials, the particles of the rubber-like polyorganosiloxane compound are uniformly dispersed. It can be used as a sealing resin composition.

An example of the latter is a rubber-like polymer containing dimethyl siloxane as a main component, which is preliminarily formed into spherical or amorphous particles and has an average particle diameter of 1 to 100 μm.
The following are preferably used. As a commercially available example, there is the Trefil E series manufactured by Toray Dow Corning Silicone Co., Ltd.

The method of introducing the rubber-like particles into the encapsulating resin composition is to disperse and mix all or part of a thermosetting resin mainly composed of a polymaleimide compound which has been heated and melted in a high share. Disperse it evenly. By melt-mixing all or part of the thermosetting resin mainly composed of the polymaleimide compound in which the rubber-like particles are dispersed together with other raw materials, the particles of the rubber-like polyorganosiloxane compound are uniformly dispersed. It can be used as a sealing resin composition. The compounding amount of the particles of the rubber-like polyorganosiloxane compound is preferably 1 to 10% by weight in the encapsulating resin composition.

The encapsulating resin composition used to obtain the resin-encapsulated semiconductor device according to the present invention includes a thermosetting resin containing the polymaleimide compound as a main component, a thermal expansion coefficient and a thermal conductivity. From this point of view, the inorganic filler is the main component, but the inorganic filler used is an inorganic filler mainly composed of crushed and / or spherical fused silica powder. In addition to this, crystalline silica, alumina, silicon nitride, silicon carbide, talc, calcium silicate, calcium carbonate,
It is also possible to mix and use powders of mica, clay, titanium white and the like. The average particle size of the inorganic filler is 5 to 50.
μm, preferably 10 to 30 μm. The blending amount of the inorganic filler needs to be 100 to 900 parts by weight, and preferably 200 to 600 parts by weight, with respect to 100 parts by weight of the thermosetting resin mainly containing the polymaleimide compound.

From the viewpoint of mechanical strength and heat resistance, it is preferable to use a coupling agent in combination with the above-mentioned inorganic filler for the purpose of improving the adhesiveness with a resin. Examples of such coupling agents include silane-based, Coupling agents such as titanate, aluminate and zircoaluminate can be used. Among them, silane coupling agents are preferable,
In particular, a silane coupling agent having a reactive functional group is most preferable.

Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane and N- (2-aminoethyl) 3-.
Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and one or more of these are used. It

In the present invention, when curing the encapsulating resin composition, it is desirable to include a curing accelerator, and examples of such a curing accelerator include 2-methylimidazole, 2-methyl-4-ethylimidazole, Imidazoles such as 2-heptadecyl imidazole; amines such as triethanolamine, triethylenediamine and N-methylmorpholine; organic phosphines such as tributylphosphine, triphenylphosphine and tritolylphosphine; tetraphenylphosphonium tetraphenylborate, triethyl Tetraphenylboron salts such as ammonium tetraphenylborate; 1,8-diaza-bicyclo (5,4,0) undecene-7 and its derivatives. Even if these curing accelerators are used alone, 2
More than one kind may be used in combination, and if necessary, an organic peroxide or an azo compound may be used in combination. The content of these curing accelerators is in the range of 0.01 to 10% by weight based on the thermosetting resin mainly containing the polymaleimide compound.

The encapsulating resin composition of the present invention contains, in addition to the above-mentioned various components, various silicone oils as required; releasing agents such as fatty acids, fatty acid salts and waxes; bromine compounds, antimony compounds, phosphorus compounds and the like. Combustion agent: A colorant or the like such as carbon black may be blended, mixed and kneaded to obtain the encapsulating resin composition for producing the resin-encapsulated semiconductor device of the present invention.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, the test method of the performance of the resin composition for closure in an Example is as follows. -Bending strength and flexural modulus: JIS K-6911-Solder dipping test: 85 semiconductor devices for testing 85
After leaving it in a constant temperature and humidity chamber of 85 ° C. and 85% for 168 hours, immediately immersing it in a molten solder bath of 240 ° C. for 10 seconds, and then using an ultrasonic flaw detector (AT-3000 manufactured by Hitachi Construction Machinery Co., Ltd.), a package resin. The number of semiconductor devices having internal cracks (including external cracks) was counted. The peeled state of the device surface was measured as the ratio of the peeled area to the total surface area of the device.

Examples 1 to 9 and Comparative Examples 1 to 3 The compositions (parts by weight) shown in Table 1 were mixed in a Henschel mixer, and further melted and kneaded for 3 minutes on a hot roll at 100 to 130 ° C. . This mixture was cooled, crushed, and tableted to obtain a resin composition for sealing.

[0027]

[Table 1] The raw materials used in Table 1 except for the synthesis example are
The following was used. -Polymaleimide compound (1); bis (4-maleimidophenyl) methane (manufactured by Mitsui Toatsu Chemicals, Inc.)-Polymaleimide compound (2); 4,4'-bis (3-maleimidophenoxy) biphenyl (Mitsui East Pressure Chemical Co., Ltd.
Polymaleimide compound (3); X in the general formula (3)
A polymaleimide compound in which is a methylene group (BMI-M
-20; Mitsui Toatsu Chemicals, Inc.) Epoxy Compound (1); EOCN-1020 (Nippon Kayaku Co., Ltd.) Epoxy Compound (2); Epikote YX-4000 (Okaka Shell Epoxy Co., Ltd.) Manufactured) Epoxy compound (3); Epiclon EXA-4300
(Dainippon Ink and Chemicals, Inc.)-Phenol compound (1); Phenol novolac resin (PN-80; Nippon Kayaku Co., Ltd.)-Phenol compound (2); Phenol aralkyl resin (XL-225LL; Mitsui) Toatsu Chemical Co., Ltd.-Phenol compound (3); Naphthol aralkyl resin (α-NX; Mitsui Toatsu Chemical Co., Ltd.)-Polyorganosiloxane (1); KE1204 (Shin-Etsu Chemical Co., Ltd.)・ Polyorganosiloxane (2); Trefil E-500
(Toray Dow Corning Silicone Co., Ltd.) Spherical fused silica; Harimic S-CO (Micron Co., Ltd.) Crushed fused silica; Hugh Rex RD-8
(Manufactured by Tatsumori Co., Ltd.) ・ Silane coupling agent; SZ-6083 (manufactured by Toray Dow Corning Silicone Co., Ltd.) ・ Flame retardant epoxy resin; Bren-S (Nippon Kayaku Co., Ltd.)
Flame retardant aid; antimony trioxide (Sumitomo Metal Mining Co., Ltd.)
・ Curing accelerator (1); C ₁₇ Z (manufactured by Shikoku Kasei Co., Ltd.) ・ Curing accelerator (2); TPP-K (Kitako Chemical Industry Co., Ltd.)
Mold release agent; Hoechst wax OP (manufactured by Hoechst Japan Co., Ltd.) Colorant: carbon black (manufactured by Mitsubishi Kasei Co., Ltd.) Using the encapsulating resin composition obtained as described above Test pieces for measuring physical properties were molded by transfer molding (180 ° C., 30 kg / cm ² , 3 minutes). In addition, the test element (12 mm × 12 mm) is mounted on the element mounting part of the lead frame for the quad flat package type semiconductor device.
After mounting the corner, transfer molding (180 ℃, 3
The test semiconductor device was obtained at 0 kg / cm ² for 3 minutes. These test moldings had 1
Post-curing was performed at 80 ° C. for 6 hours. The test results are shown in Table 2.

[0028]

[Table 2]

[0029]

As described in the examples and comparative examples, the resin-encapsulated semiconductor device according to the present invention is encapsulated by a resin composition having high strength at high temperature and low elastic modulus. Further, when it is surface-mounted by the flow soldering method, it is a highly reliable resin-encapsulated semiconductor device that exhibits excellent crack resistance and peeling resistance, and is an industrially useful invention.

(72) Inventor Motoyuki Torikai 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Kotaro Asahina 1190, Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd. Within

Claims (1)

[Claims] 1. A resin-encapsulated semiconductor device, wherein a semiconductor element is encapsulated with a resin composition having the following characteristics (A) and (B). (A) The flexural strength of the cured product of the resin composition at 240 ° C. is 4 kg / mm ² or more. (B) The flexural modulus at 25 ° C. of the cured product of the resin composition is 1400 Kg / mm ² or less.