JPH0468017A - Resin composition for semiconductor sealing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a resin composition for semiconductor encapsulation, and more particularly to a resin composition for semiconductor encapsulation that is excellent in heat resistance, moldability, and resistance to overheating.

[Conventional technology]

In the field of electrical equipment, electronic components, and especially semiconductors, there is a trend towards high-market packaging and multi-functionality, and the materials used to seal these components are resin compositions that have excellent heat resistance against high-temperature solder during the mounting process. The development of products is strongly desired. Conventionally, as resin compositions for semiconductor encapsulation, 0-cresol novola,
Resin compositions containing epoxy resins such as epoxy resins, their curing agents, and phosphoric acid as main components have become mainstream because they are excellent in moldability and foldability.

[Problems to be Solved by the Invention] As a recent trend, resin-sealed semiconductor devices are being replaced by surface-mounted semiconductor devices due to the aforementioned trend toward high-density packaging.

In such a surface mount type semiconductor device, unlike a conventional insertion type semiconductor device, the entire semiconductor device is exposed to temperatures of 200° C. or higher during the soldering process to the substrate. At this time, a problem has arisen in that cracks occur in the sealing resin, significantly reducing the reliability of the semiconductor device. From this point of view, many studies have been conducted on the use of imide-based resins, which have excellent heat resistance, with the aim of improving resin strength. However, cured products of imide-based resins have problems in terms of flexibility and moldability. Therefore, attempts have been made to balance moldability and heat resistance by using it in combination with epoxy resin.

However, imide-based resins have a problem in that they have poor mold releasability and the molded product adheres to the mold during demolding. This is because the internal mold release agent conventionally used in epoxy resin systems has poor compatibility with imide resin systems, making it difficult to uniformly disperse it in the resin composition, resulting in the mold release agent bleeding into the mold. This is because the molding becomes uneven and the molded product partially adheres to the mold.

In order to solve this problem, if a large amount of internal mold release agent is used, the adhesion between the semiconductor element and the lead frame will decrease, and this will cause a decrease in moisture resistance. An object of the present invention is to provide an imide resin encapsulating resin composition having excellent heat resistance, moldability, and moisture resistance.

[Means to solve the problem]

The present inventors have conducted extensive research aimed at improving the heat resistance, moldability, and moisture resistance of resin compositions by using epoxy resins and imide resins in combination, and found that in order to impart good mold releasability, We learned that it is necessary to select a mold release agent that is compatible with imide resins, and that using a certain type of mold release agent in combination can reduce the adhesion even when epoxy resins and imide resins are used together. The present invention has been completed by successfully achieving both good moldability and excellent heat resistance and moisture resistance.

That is, the present invention provides (1) essentially a polymaleimide (A), an epoxy resin (B), an epoxy curing agent (C), and an inorganic filler (D).
), as an internal mold release agent, A
A resin composition comprising an ester wax (E) having an acid value of 10 to 50 according to STM-D-1386 and an acid wax (F) having an acid value of 100 to 180,
(2), the total amount of ester wax (E) and acid wax (F) is polymaleimide (A), epoxy resin (B)
, 0.3 to 2.0 parts by weight per 100 parts by weight of the total amount of epoxy curing agent (C), and (F)/(E) is 0.1 to 0.4 in weight ratio. (3) A resin composition for semiconductor encapsulation, characterized in that the resin composition according to claim (1) is used for resin encapsulation of a semiconductor, (4) , a resin composition for semiconductor encapsulation, characterized in that the resin composition according to claim (2) is used for resin encapsulation of a semiconductor.

Examples of the polymaleimide (A) used in the present invention include N,N'-ethylene bismaleimide, N,N'
-hexamethylene bismaleimide, N,N-(1,3-
phenylene) bismaleimide, N,N'-(1,4-
phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(4-maleimidophenyl)ether, bis(3-10-4-maleimidophenyl)methane, bis(4-maleimidophenyl)sulfone, bis(
4-maleimidomethylhexyl)methane, 1,4-bis(maleimidomethyl)cyclohexane, 1,4-bis(
maleimidophenyl)cyclohexane, 1,4-bis(
Among them, the following two types of polymaleimides are preferably used in the present invention.

The first type represents a divalent group consisting of the following general formula (■): where X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, Indicates a group selected from the group consisting of carbonyl group, thio group, sulfinyl group, sulfonyl group, and oxo group. ) is a bismaleimide represented by Such bismaleimide can be prepared by general formula (II) (wherein R3 has the same meaning as in general formula (1)) by a commonly known method.

) can be easily produced by a condensation/dehydration reaction between the diamine represented by the formula and maleic anhydride.

Specifically, the above bismaleimides include 1,3-bis(3-maleimidophenoxy)henzen, bisC4-(
3-Maleimidophenoxy)phenyl]methane, 1,1
-bis[4-(3-maleimidophenoxy)phenyl]
Ethane, 1,2-bis[4(3-maleimidophenoquine)phenyl]ethane, 1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane, 2,2-bis[4
~(3-maleimidophenoquine)phenyl]propane,
2.2bisC4-(3-maleimidophenoxy)phenyl]butane, 2,2-bisC4-C3-maleimidophenoxy)phenyl) -1,1,1,3,33,-hexafluoropropane, 4,4- Bis(3-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenylkoketone, bis[4-(3-maleimidophenoxy)phenyl]sulfite, HisCd-(
3-maleimidophenoquine) phenyl] sulfoquine,
Examples include bisC1(3-maleimidophenoquino)phenyl]sulfone, bis(4-(3-maleimidophenoxy)phenyl)ether, etc. As the second type, the following general formula (■): (in the formula, f is an average value of 0 to 10.) Such a polymaleimide has the general formula (■) H2 (wherein, l is an average value of O to 10). It can be easily produced by condensing and dehydrating the polyamine shown above and maleic anhydride.One type or two or more types of these polymaleimides are used.

Any epoxy resin (B) can be used as long as it has at least two eboxo groups in the molecule, and specific examples include reactions between phenols such as phenol, cresol, and redunonol, and aldehydes. , Novola-type epoxy resin derived from novolak resin, which is a product, and aralkyl-type epoxy resin derived from aralkyl resin, which is a reaction product of the above-mentioned phenols and aralkyl ether order. It is preferable from the viewpoint of 7.

In addition, epoxy resins derived from compounds having two or more active hydrogen atoms in one molecule, such as bisphenol A, bisphenol F, resolnon, bishydroquinodiphenyl ether, bishydroquinodiphenol, tetrabromobispheno Jl/A ,) Polyhydric phenols such as lihydroquinophenylmethane, tetrahydroxyphenylethane, alkane tetrakisphenol; Polyhydric alcohols such as ethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diethylene glycol, polypropylene glycol, etc. ; ethylenediamine, aniline, bis(4-
amines such as (aminophenyl)methane; epoxy resins obtained by reacting polycarboxylic acids such as adipic acid, phthalic acid, and isophthalic acid with epichlorohydrin or 2-methylepichlorohydrin; one or two of these epoxy resins More than one type is used.

Furthermore, as the epoxy resin (B), it is also possible to use an epoxy resin modified with an oily or rubbery silicone compound.

For example, JP-A-62-270617, JP-A-62-2
There are silicone-modified epoxy resins produced by the method disclosed in No. 73222.

All known epoxy curing agents (C) can be used, but compounds having two or more phenolic hydroxyl groups in one molecule are particularly preferably used. Specifically, novolak phenol resin is a reaction product of phenols such as phenol, cresol, and resorcinol and aldehydes, and aralkyl phenol resin trihydroxyphenylmethane is a reaction product of the above phenols and aralkyl ethers. , tetrahydroxyphenylethane, alkanetetrakisphenol, and other polyhydric phenols, and one or more of these may be used. Moreover, amines and acid anhydrides can also be used in combination with the above compounds. Polymaleimide (A),
The amount of the epoxy resin (B) and the epoxy curing agent (C) is as follows:
The amount is 10 to 500 parts by weight, preferably 25 to 300 parts by weight.

In addition, the ratio of the epoxy resin (B) and the epoxy curing agent (C) to the epoxy resin (B) is
) is in the range of 0.1 to 10 in equivalent ratio, preferably 0.5 to 10.
The range is 2.

Inorganic fillers (D) include powders such as silica, alumina, silicon nitride, silicon carbide, talc, rhusium silicate, rhusium carbonate, mica, clay, and titanium white; fibers such as glass fiber and garbon fiber. Illustrated.

Among these, crystalline warping force and/or fused silica is preferred from the viewpoint of thermal expansion coefficient and thermal conductivity. Furthermore, considering the fluidity of the resin composition during molding, the shape is preferably spherical or a mixture of spherical and irregular shapes.

The blending amount of the inorganic filler (D) is polymaleimide (A),
It needs to be 100 to 900 parts by weight, preferably 200 to 600 parts by weight, based on 100 parts by weight of the total amount of the epoxy resin (B) and the epoxy curing agent (C).

In addition, 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 (D) for the purpose of improving adhesiveness with the resin, and such coupling agents include silane-based, Coupling agents such as thicnate, aluminate, and zircoaluminate can be used.

Among them, silane coupling agents are preferable, and in particular,
Most preferred are silane coupling agents having a functional group that reacts with epoxy resins and polymaleimides. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethquinsilane, N-(2-aminoethyl)3-aminopropylmethyldimethquinsilane, N-(2-aminoethyl)3-aminopropyl Trimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glydoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxinelan, 2-(3,4-epoxy cyclohexyl)ethyltrimethoxysilane, 3
-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxynolane, etc., and one or more of these may be used.

In the present invention, in curing the resin composition,
It is desirable to use curing accelerators.

Such curing accelerators include 2-methylimidazole,
Imidazoles such as 2-methyl-4-ethylimidazole; triethanolamine, triethylenediamine, N
- Amines such as methylmorpholine; organic phosphines such as tributylphosphine, triphenylphosphine, and tritolylbosphine; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triethylammonium tetraphenylborate; 18-
Diaza-bicyclo(54,0) undecene-7 and its derivatives. The above-mentioned curing accelerator may be used alone or in combination of two or more types, and a radical initiator such as an organic peroxide or an ab compound may also be used in combination.

The amount of these curing accelerators used is in the range of 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the polymaleimide (A), epoxy resin (B) and epoxy curing agent (C). The internal mold release agent, which is the most important component in the present invention, has two types of wax-based internal mold release agents as essential components, and the first type is ASTM-D-
Ester wax with an oxidation rate of 10 to 50 by 1386 (
E).

These mold release agents are Hoechst Wanox E from Hoechst.
It is commercially available as 5Hextowanox KPE and the like.

The second type is acid wax (F) with an oxidation rating of 100 to 180 according to ASTM-D-1386. These mold release agents are Hoechst wax S,
It is commercially available as Hoechstwa, Kusu LP, etc.

The blending amount of the two types of mold release agents in the present invention is such that the total amount of ester wax (E) and acid wax (F) is the same as that of polymaleimide (A), epoxy resin (B), and epoxy curing agent (C).
) is 0.3 to 2.0 parts by weight based on the total amount of 100!1 parts, and if the amount used is less than 0.3 parts by weight, the mold release property is poor, and the amount used is 2.0 parts by weight. When the value exceeds the semiconductor element,
The adhesion with the lead frame will deteriorate, and the durability will deteriorate. It causes sexual decline. In addition, (F)/(E) must be in a weight ratio of 0.1 to 0.4, and the weight ratio is 0.1.
If it is less than 0.0, it has poor compatibility with the imide resin.
If it exceeds 4, the adhesion with the lead frame and semiconductor element is poor, and especially (F) alone has too strong a mold release effect.
It is difficult to maintain a balance with adhesion, and the object of the present invention cannot be fully achieved.

In addition to the above-mentioned components, the cough resin composition also contains, if necessary,
A bromine compound, a flame retardant such as antimony or phosphorus, a coloring agent such as carbon black, various silicone oils, etc. can be blended, mixed and kneaded to form a molding material.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

Synthesis Example 1 (Polymaleimide (1)) 43.2 g (0.44 mol) of maleic anhydride and 130 g of acetone were put into a reaction vessel equipped with a stirrer and a thermometer and dissolved. To this, 73.6 g (0.2 mol) of 4,4′-bis(3-aminophenoquine)biphenyl
A solution prepared by dissolving 515 g of acetone was added dropwise at room temperature, and the mixture was further stirred at 23 to 27°C for 3 hours. After the reaction was completed, it was dried to obtain bismaleamic acid as yellow crystals.

112 g of this bismaleamic acid was suspended in 300 g of acetone, 9.6 g of triethylamine was added, and the mixture was stirred at room temperature for 30 minutes.

After adding 0.4 g of cobalt (II) oxide ・4H, 52 g of acetic anhydride was added dropwise at 25°C over 30 minutes, and
Stir for an hour.

After the reaction was completed, the generated crystals were filtered, washed, and dried to obtain polymaleimide (1).

The yield is 84.5g, and the 11 go is 80χ compared to the theoretical yield.
The temperature was 195-200°C.

Synthesis Example 2 (Polymaleimide (2)) Aniline 111.
6 g (1.2 moles) and 70.0 g ('0.4 moles) of α,α'-dichloro-P kiln were charged, and the temperature was raised while passing nitrogen gas. Although heat generation was observed from an internal temperature of about 30°C, the temperature was raised and kept constant at 85-100°C for 3 hours. After this, continue to raise the temperature to 190-200
The reaction was carried out for 20 hours at "C". Then, the inner hot water was cooled down to 95 °C, and a 15% aqueous solution of caustic soda was added at 230 °C.
g was added and neutralized by stirring. After standing still, the lower aqueous layer was separated and removed, 300 g of saturated saline was added, and washing and separation were performed. Next, the mixture was heated and dehydrated under a nitrogen stream, and then filtered under pressure to remove inorganic salts and the like.

This was vacuum-condensed at 2 to 3 Torr to recover unreacted aniline.

Next, 35.8 g (0,358 mol) of maleic anhydride and 40 mol of acetone were placed in a reaction vessel equipped with a stirrer and a thermometer.
g was charged and dissolved. When 50 g of the above aniline resin was dissolved in 50 g of acetone and the volume was diluted, crystals were precipitated and the mixture was stirred at 25° C. for 3 hours. Thereafter, 8.5 g of triethylamine was added and the mixture was stirred at 25°C for 30 minutes.

After adding 0.35 g of magnesium oxide (U) and 111200.035 g of cobalt (II) acetate,
Charge 45.5 g of acetic anhydride, stir at 50 to 55°C for 3 hours, cool to 25°C, drop the reaction solution into water 11 with stirring, filter the formed crystals, wash with water, After drying, brown crystalline polymaleimide (2) was obtained. As a result of compositional analysis of this polymaleimide (2) by high performance liquid chromatography, -Noshiro (I[[) 2=0 is 25%
,! =1 is 23%, l'=2 is 17%,! ≧3 is 35%
Met. The yield was 74.2 g, the ratio to the theoretical yield was 9881%, and the melting point was 115-130'C.

(Fixing the coupling agent to the surface of the inorganic filling side) 50 parts by weight of fused silica with an average particle size of 18μ (Fuzure, Kusu RD-8, manufactured by Roshimori) and 1 container silica with an average particle size of 20μ (Harimic 5-CO2) 1 part by weight of N-(2-aminoethyl)3aminomethyltrimethoxysilane was added to 50 parts by weight (manufactured by Micron) and mixed for 20 minutes using a henonyl mixer.

Then, spread this mixture on a stainless steel hunt and spread it for 1
It was dried at 10'C for 2 hours to obtain treated silica.

Examples 1 to 4 and Comparative Example 1.2 Polymaleimide obtained in the synthesis example, epoxy resin (0-
Cresosol novolanok type epoxy resin; EOCN-
1020 Nippon Kawara (1)), Evoquino curing agent (novolac phenol resin; PN-80, Nippon Kajimi)
and various mold release agents were put into a flask equipped with a stirrer at υ1 as shown in Table 1, melted and mixed at 130'C for 5 minutes, spread in a stainless steel hat, and rapidly cooled to obtain a mixture.

A small amount of these mixtures is placed on a slide glass placed on a hot plate adjusted to 130°C, covered with a cover glass, and the container is closed. Thereafter, the slide glass was taken from the hot plate, slowly cooled at room temperature, and the molten state was observed.

Examples 5 to 10 and Comparative Examples 3 to 6 Blends having the compositions (parts by weight) shown in Table 2 were mixed using a hennonyl mixer, and further melted and kneaded for 3 minutes using heated rolls at 100 to 130°C.

This mixture was cooled, pulverized, and tableted to obtain a molding resin composition. In addition, with the raw materials used in Table 2, synthesis examples]
, 2, the following were used.

Epoquino resin: 0-Taresol novolac type epoxy resin (EOCN-1020, manufactured by Nippon Kaya@) / Epoquino hardening, novolac phenol resin (PN-80, manufactured by Nippon Kajimi) ・Curing accelerator (1): l- Riphenylphosphine (TP)
P, manufactured by Hokkoshi Kagaku) ・Curing accelerator (2) ;) Ethylammonium tetraphenylborate (TEA-k, Hokukoshi Kagaku ■) Mold release agent (1); Hoechstwax 7x E, oxidation 17 ( Made by Hoechst Java ■) ・Mold release agent (2), Hoechstwa, Cus KPE oxidation 30 (
Mold release agent (3), Hexstowanox S, d-145 (manufactured by Hoechstoji Pan) Mold release agent (4), Hexstowanox LP, u-120 (manufactured by Hexstoji Pan) As above Using the molding resin composition obtained in step 5,
Transfer molding (180°C130kg/cm2.
3 minutes) A test piece for measuring physical properties was molded.

In addition, the element mounting part-2 of the lead frame for a Furano-Tobanokeno type semiconductor device was equipped with aluminum bonding butts of 100μ x 100μ and 1μ thick at the four corners, and aluminum wiring with a width of 10μ to connect these parts ( 10mm x 10mm square), and after connecting the gold wire tellid frame and bonding band part, transfer molding (180°C, 130kg/cm, 2.3 minutes)
As a result, a test semiconductor device was obtained.

These test moldings were rotated 180° before each test.
Post-curing was carried out at C for 6 hours. The test results are shown in Table 3.

The test method is as follows.

・Glass transition temperature, TMA method, bending strength, JIS K-6911 mold releasability; After molding the test semiconductor device, when releasing the test semiconductor device from the mold, runner deformation, gate residue, and mold release properties Qualitatively judge the ease of removal, etc.

・V, p, s test: test semiconductor device at 121°C
After being left in a 12-atm pressure pressure tester for 24 hours, the semiconductor devices were immediately placed in a molten solder bath at 260° C., and the number of semiconductor devices with cracks in the package resin was counted. The test value is expressed as a fraction, where the numerator is the number of semiconductor devices in which cranking occurred, and the denominator is the total number of semiconductor devices subjected to the test.

Adhesion test: A resin composition tableted to a size of 10 mmφ and 2 mm thick was sandwiched between two pieces of 42 alloy of 50 x 70 x 0.25 mm, and cured under pressure (180'C130kg/cm2.
3 minutes). This test piece was pulled with a tester for 42
70 pieces were pulled in the longitudinal direction, and the strength when the 4270 pieces were peeled off was measured and defined as the adhesive strength.

Moisture resistance test; 121 test semiconductor devices, 25 each
The sample was left in a pre-shock tester at 12 degrees Celsius, and continuity checks were performed at regular intervals to determine the time at which the failure rate due to corrosion of the aluminum wiring reached 50%.

Table 1 ? Yong 8 刹 dog state: ○・　・　・transparent.

×・・・Precipitate present [Effect of the invention] As explained in the examples and comparative examples, the semiconductor resin composition according to the present invention has the ability to efficiently impart the heat resistance of an imide resin and the moldability of an epoxy resin. It is possible. Furthermore, when reflow and flow soldering methods are used to encapsulate surface-mounted semiconductor devices to which this resin composition is applied, it exhibits excellent solder heat resistance, moldability, and moisture resistance, and is highly reliable. This invention is industrially useful since it is possible to obtain a static type semiconductor device.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (4)

[Claims] (1), essentially consisting of a polymaleimide (A), an epoxy resin (B), an epoxy curing agent (C) and an inorganic filler (D).
), which contains an ester wax (E) having an acid value of 10 to 50 according to ASTM-D-1386 and an acid wax (F) having an acid value of 100 to 180 as internal mold release agents. A resin composition characterized by: (2), the total amount of ester wax (E) and acid wax (F) is polymaleimide (A), epoxy resin (B)
, 0.3 to 2.0 parts by weight based on 100 parts by weight of the total amount of epoxy curing agent (C), and (F)/(E) is 0.1 to 0.4 in terms of weight ratio. The resin composition according to claim 1. (3) A resin composition for semiconductor encapsulation, characterized in that the resin composition according to claim (1) is used for resin encapsulation of a semiconductor. (4) A resin composition for semiconductor encapsulation, characterized in that the resin composition according to claim (2) is used for resin encapsulation of a semiconductor.