JPH0834927A - Sealing resin composition - Google Patents

Abstract

PURPOSE:To obtain the composition, containing a silicone fine powder having reactional functional groups on the surface, having a small internal stress and high reliability, excellent in interfacial adhesion and useful as a sealing material for transistors, IC's, etc. CONSTITUTION:This sealing resin composition contains a silicone fine powder having reactional functional groups (preferably epoxy, an alkoxy, silanol, SiH, amino, hydroxyl group, etc.) on the surface and preferably 0.02-200mum, especially preferably 0.1-50mum average particle diameter D50. Furthermore, the silicone fine powder is preferably contained in an amount of preferably 0.1-90wt.%, especially preferably 0.5-40wt.% based on the weight of the composition. The silicone fine powder is preferably prepared by modifying a silicone having silanol groups on the surface with a silane coupling agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealing resin composition.

[0002]

2. Description of the Related Art With the advance of technology in recent years, semiconductors are now highly integrated such as LSI and VLSI. This highly integrated semiconductor device is sealed with a synthetic resin composition to protect it from the external environment. However, the coefficient of thermal expansion of a synthetic resin composition generally used as a semiconductor encapsulating material is much higher than the coefficient of thermal expansion of a semiconductor element. Therefore, the difference in the coefficient of thermal expansion is
Excessive internal stress is applied to the semiconductor element by encapsulation, after-cure, or subsequent thermal history (Nikkei Microdevice, issued June 11, 1984). In addition, it also causes cracks in the semiconductor encapsulating material and creates a gap between the semiconductor encapsulation material and water, which intrudes into the gap to corrode the wiring and cause deterioration of the semiconductor element.

It is known that the composition of silicone having a damper effect is effective for relieving the internal stress of the semiconductor encapsulating material, and that the internal stress can be further relieved by increasing the compounding amount of the silicone. There is. Therefore, it has been attempted to add a larger amount of silicone. According to this method, the fluidity of the sealing material was remarkably reduced, and casting, transfer molding, potting, dropping and other operations were substantially impossible.

Therefore, it has been proposed to use a thermosetting resin composition having a low coefficient of thermal expansion and a low internal stress without lowering the fluidity as a semiconductor encapsulating material. Japanese Examiner Sho 62
-28971, a thermosetting epoxy resin composition in which a polymer cured product containing 10% by weight or more of a linear organosiloxane block is dispersed, or Japanese Patent Publication No. 3-30
No. 620 and Japanese Patent Publication No. 63-12489,
A spherical cured polymer and a thermosetting epoxy resin composition having the polymer dispersed therein are disclosed.

However, in general, silicone has poor adhesiveness as used as a release agent and has the property of peeling at the interface. Therefore, the use of silicone in the encapsulating material causes a defect that the adhesiveness between the encapsulating material and the semiconductor element is reduced. As a result, water enters the interface between the sealing material and the semiconductor element, corrodes the wiring, and deteriorates the semiconductor element. That is, the encapsulating material containing silicone has one side inferior in moisture resistance.

Particularly, in recent years, the semiconductor itself has become vulnerable to stress in terms of high-density packaging. In addition, packages tend to be smaller and thinner for surface mounting, and there has been a phenomenon that the life of the package is extremely shortened due to a shortened water entry path. For this reason, measures have been taken to add special functional groups to silicone and to reduce the particle size.
Various problems such as an increase in impurities and a decrease in liquidity have occurred and have not been solved yet.

The conventional silicone fine powder is liable to cause secondary agglomeration, so that it is not easy to uniformly mix the silicone fine powder when producing an epoxy resin composition or the like.

In view of the above-mentioned various problems, the present applicant has already proposed that the surface-oxidized silicone fine powder having an average particle diameter of 0.02 to 200 μm is 0.1 to 90 weight% of the composition. An application was made for a resin composition for encapsulation, which contains 50% by weight of the silicone fine powder and has an oxide layer thickness of 90% or less of the particle size (Japanese Patent Application No. 6-78150).

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a highly reliable encapsulating resin composition having a small internal stress and excellent interfacial adhesion.

[0010]

Means for Solving the Problems The present inventors have conducted various studies in order to find a resin composition for encapsulation having improved adhesiveness while retaining the advantage of using silicone. As a result, they have found that the above problems can be effectively solved by using finely divided silicone powder having a reactive functional group on the surface, and have completed the present invention.

That is, the present invention is a resin composition for encapsulation, which comprises a fine silicone powder having a reactive functional group on the surface thereof.

The average particle diameter of the silicone fine powder of the present invention is a particle diameter D ₅₀ corresponding to 50% of the cumulative distribution, and preferably 0.
It is from 02 to 200 μm, particularly preferably from 0.1 to 50 μm. If the average particle size is less than the above lower limit, the viscosity of the encapsulating resin composition is increased, the fluidity is lowered, and high filling is difficult. Exceeding the above upper limit is not preferable because local stress is generated in the resin composition. Here, the average particle size of the silicone fine powder is a value obtained by observation with a scanning electron microscope.

The silicone fine powder preferably has a particle size distribution of 90% by weight or more of particles having a particle size of 150 μm or less, and particularly preferably 95% by weight or more of particles having a particle size of 74 μm or less. 9 particles less than 150 μm
If it is less than 0% by weight, local stress is generated, which is not preferable.

The silicone fine powder having the desired average particle size can be prepared, for example, as follows. When the silicone is prepared by bulk polymerization, it is carried out by pulverizing the produced silicone into a fine powder of silicone having the above-mentioned desired average particle size or further sieving. Further, in the case of preparing a silicone by emulsion polymerization, for example, a liquid silicone rubber composition that can be cured by heat is dispersed in water at a temperature of 25 ° C. or less, and the composition is dispersed in water as a discontinuous phase. It can be prepared by a method of preparing a dispersed dispersion, and then dispersing the dispersion in a liquid having a temperature of 50 ° C. or higher to cure the liquid silicone rubber composition (JP-A-63-77).
942). It can also be prepared by a method using a spray dryer described in JP-B-63-12489 or JP-B-3-30620.

The fine silicone powder used in the present invention has a reactive functional group on its surface. The reactive functional group is preferably one capable of forming a stable bond with silica and a resin, and preferably selected from the group consisting of an epoxy group, an alkoxy group, a silanol group, a hydrosilyl group, an amino group, a hydroxyl group and a mercapto group. And at least one group. Functional groups other than the above may cause a drawback that the reliability of the obtained semiconductor is lowered. For example, a silicone fine powder having a carboxyl group is not preferable because it causes hydrolysis after sealing and corrodes the semiconductor element. As a method for imparting the above-mentioned reactive functional group to the surface of the silicone fine powder, preferably the following methods can be mentioned.

The first method is as follows. Silicon fine powder having a desired average particle size prepared as described above, for example, a method by thermal spraying, a method by plasma spraying,
Alternatively, the surface-oxidized silicone fine powder is prepared by subjecting it to an oxidation treatment by a method using a rotary or fixed heating furnace. A method by thermal spraying, a method by plasma spraying or a method using a rotary heating furnace is preferable, and by using the method, the shape of the fine silicon powder during the surface treatment can be made into a shape without corners, preferably a spherical shape. It is preferable to use the silicone fine powder having such a shape because the amount of the silicone fine powder used can be increased without lowering the fluidity of the resin composition. The oxide layer thickness of the silicone fine powder is preferably 90% or less, particularly preferably 1 to 50% of the particle size of the silicone fine powder. When the thickness of the oxide layer exceeds the above upper limit, the effect of relaxing the internal stress decreases, which is not preferable.

The temperature of the oxidation treatment is preferably 200-
1,500 ° C., particularly preferably 400-1,000 ° C. If the temperature is lower than the lower limit, the oxidation efficiency is poor, and if it exceeds the upper limit, extreme mineralization occurs, which is not preferable.

In the actual operation, the oxidation treatment temperature or the oxidation treatment time can be easily determined experimentally, and the thickness of the oxide layer of the silicone fine powder can be controlled to a predetermined value. The oxide layer thickness can be calculated by quantifying silanol groups using FTIR.

By the above oxidation treatment, silanol groups are formed on the surface of the silicone fine powder.

Next, a compound having a group capable of reacting with a silanol group (eg, SiOR) and the above-mentioned reactive functional group is added to the silicone fine powder and reacted,
Reactive functional groups are provided on the surface of the silicone fine powder. Examples of such compounds include silane coupling agents, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane; γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N- β (aminoethyl) γ
-Aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminoisobutylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; γ-mercaptopropyltrimethoxysilane,
γ-mercaptopropylmethyldimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane; and γ-
Methacryloxypropyltrimethoxysilane and γ-methacryloxypropylmethyldimethoxysilane may be mentioned. Here, the addition amount of the silane coupling agent is preferably 0.1 to 1 with respect to 100 parts by weight of the silicone fine powder.
0 parts by weight. The reaction is carried out with stirring, preferably 20 to 1
It is carried out at 40 ° C. for 1 minute to 24 hours. The addition of the silane coupling agent can be performed, for example, by spraying the silicone fine powder with an aqueous solution of the silane coupling agent, or by adding the silane coupling agent to an aqueous slurry of the silicone fine powder. At this time, an acid or a base may be added as a catalyst.

The silicone used here is, for example, dimethyl silicone, diphenyl silicone, methylphenyl silicone, methyloctyl silicone, methylcyclohexyl silicone, methyl (α-phenylethyl) silicone, methyl (3,3,3-trifluoropropyl). ) Silicone, dimethyl silicone / diphenyl silicone copolymer, methyl vinyl silicone, dimethyl silicone / methyl vinyl silicone copolymer, or the like, or any combination thereof may be used. Dimethyl silicone is preferred from the economical point of view.

The degree of polymerization of the above silicone is preferably 1
It is 0 to 1,000, particularly preferably 20 to 1,000. If it is less than the above range, the effect on the thermal expansion coefficient and internal stress of the encapsulating resin composition is small, and if it exceeds the above range, pulverization becomes difficult, which is not preferable. As the silicone, for example, a compound of the formula-(R ₂ SiO) _-n (wherein R is the same or different monovalent hydrocarbon group, and n is the cured state described in Japanese Patent Publication No. 62-28971) is used. A cured product of a polymer containing 10% by weight or more of a linear organopolysiloxane block represented by an integer of 10 or more), or JP-B-63-12489 and JP-B-3-3062.
It is possible to use a spherical cured product or the like in which n in the above-mentioned formula described in Japanese Patent Publication No. 0 is an integer of 5 or more.

The second method is as follows. Silicon compounds containing alkoxy groups such as isobutyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, tetramethoxysilane, or tetraethoxysilane subjected to hydrolysis and dehydration condensation To prepare. At this time, as a catalyst, organic acids such as formic acid and acetic acid, mineral acids such as hydrochloric acid and sulfuric acid, amines such as triethylamine and diazabicyclounden, alkalis such as sodium hydroxide and potassium hydroxide, or zinc octylate and octyl Salts such as tin acid and dibutyltin laurate can be used. Here, the polymerization degree of the produced silicone is preferably in the same range as the silicone used in the first method. In order to obtain silicone fine powder having the above-mentioned predetermined average particle size, silicone can be produced by bulk polymerization and pulverized under cooling with liquid nitrogen to obtain a predetermined particle size. The silicone fine powder has silanol groups on its surface.

Next, the above-mentioned compound such as a silane coupling agent is added to the silicone fine powder and reacted to give a reactive functional group to the surface of the silicone fine powder. Here, the addition amount of the silane coupling agent is the same as in the first method.

The third method uses a silanol group-containing silicon compound instead of the alkoxy group-containing silicon compound used in the second method. Examples of silanol group-containing silicon compounds include dimethylsilanediol, dimethoxysilanediol, trimethoxysilanol, triethoxysilanol, and diphenylsilanediol. The produced silicone fine powder has silanol groups remaining on its surface.

Next, the above-mentioned compound, for example, a silane coupling agent, is added to the silicone fine powder and reacted to give a reactive functional group to the surface of the silicone fine powder. Here, the addition amount of the silane coupling agent is the same as in the first method.

The fine silicone powder is contained in an amount of preferably 0.1 to 90% by weight, particularly preferably 0.5 to 40% by weight, based on the weight of the encapsulating resin composition. Below the above lower limit,
If the effect of alleviating the internal stress cannot be obtained and the amount exceeds the above upper limit, the thermal expansion coefficient of the resin composition increases or the viscosity increases, and the fluidity decreases, which is not preferable.

The silicone fine powder used in the present invention preferably has a small amount of ionic impurities. That is, the total amount of ions when extracted with pure water at 120 ° C. for 20 hours is preferably 50 ppm or less, particularly preferably 10 ppm or less. When the total amount of ions exceeds the above value, corrosion of the wiring of the semiconductor element is promoted, which is not preferable.

The resin used in the present invention may be a resin usually used, for example, bisphenol type, biphenol type, cresol novolac type epoxy resin, silicone resin, polyimide resin, alkyd resin, unsaturated polyester resin, acrylic resin. , Or Japanese Examined Japanese Patent Sho 62-2
Examples thereof include block copolymers of the above-mentioned resin and silicone described in JP-A-8971. If the content of ionic impurities is large, the resin adversely affects the moisture resistance reliability of the semiconductor after encapsulation. Therefore, it is preferable that the content of ionic impurities such as sodium ions and chlorine ions is as small as possible.

The curing agent used in the present invention may be a commonly used one, and examples thereof include polyhydric phenols, aromatic polybasic acids, aromatic polyamines, acid anhydrides and silicones. For example, novolaks such as phenol novolac, biphenol type novolac, bisphenol A type novolac, acid anhydrides such as phthalic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, and amines such as diaminodiphenylmethane, diaminodiphenyl sulfone, and metaphenylenediamine. Is used.

As the filler, those having a small coefficient of thermal expansion such as silica, silicon nitride, alumina, aluminum nitride, talc and clay are used.

In addition to the components described above, the resin composition of the present invention contains, if necessary, various additives that are usually used, such as curing catalysts such as tertiary amines and organic phosphorus compounds, or flame retardants. Materials, colorants, release agents, coupling agents and the like can be added.

The resin composition of the present invention can be prepared by kneading the components described above with a kneader, roll, mixer or the like.

The encapsulating resin composition of the present invention is extremely useful as an encapsulating material for electronic parts such as transistors, ICs, diodes and thermistors, and various electric parts such as coils of transformers and resistors.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0036]

EXAMPLES The evaluation methods used in the present invention are as follows. <Ease of compounding> 5g / m of silicone fine powder put in a cylinder
A load of m ² is applied to cause blocking. This one
The mixture was shaken on a 00 mesh screen for 20 seconds, and the proportion of silicone remaining on the screen was determined. ◯: Good less than 10% Δ: Normal 10% or more, less than 50% X: Poor 50% or more <Fluidity> Measured using the spiral flow method according to EMMI 1-66. ◯: Good Δ: Normal x: Poor <Thermal expansion coefficient> Measured using a thermal expansion coefficient meter (TMA). <Elastic Modulus> According to JIS K-6911, the elastic modulus was measured using a bending elastic modulus meter. <Interfacial Adhesion> A bending test piece is prepared from each resin composition, and the bending test piece is left under conditions of 125 ° C. and 100% humidity for 20 hours, and then broken. This fractured surface was observed by SEM, and it was examined whether or not the interface between the silicone and the resin had a gap of 0.1 mm or more. In the fluorescent liquid penetration test, the interface is broken after the test piece is immersed in the fluorescent liquid overnight. The fracture surface is observed with a fluorescence microscope to confirm the degree of penetration of the fluorescent liquid. The evaluation in Table 1 shows the following contents. Strength: Neither the interface having a gap of 0.1 mm or more nor the infiltration of the fluorescent liquid was observed. Medium: Either an interface having a gap of 0.1 mm or more or infiltration of a fluorescent liquid was observed. Weak: Both an interface having a gap of 0.1 mm or more and infiltration of the fluorescent liquid were observed. <Cold and thermal shock resistance (T / C)> I sealed in the examples
Package cracks were observed after C was subjected to a thermal history of -65 ° C to room temperature to 150 ° C for 1000 cycles, and the results are shown as the number of cracks generated / total number of tests. <Moisture resistance (PCT)> 1 of the sealed IC in the example
The results after 1000 hours of standing at 25 ° C. and 100% humidity are shown by the number of corrosion occurrences / total number of tests. <Moisture resistance after soldering (PCT after soldering)> The IC sealed in the example is left under conditions of 85 ° C and 85% humidity for 168 hours, and then immersed in a solder bath at 260 ° C for 10 seconds. afterwards,
The results after standing for 500 hours at 125 ° C. and 100% humidity are shown as the number of corrosion occurrences / total number of tests. <Comprehensive Evaluation> Each symbol in Table 1 has the following contents. ◎: Very good ○: Good ×: Poor

[0037]

Examples 1 to 6 and Comparative Examples 1 to 3 <Preparation of Silicone Fine Powder Having Reactive Functional Group on Surface> Production Example 1 Dimethyl silicone intermediate (NUC, M ₂ vinyl, D
_A catalytic amount of sulfuric acid was added to ₄ ), and this was polymerized by stirring at room temperature for 3 hours. Next, the mixture was neutralized with heavy sow and then filtered. Then, after washing with pure water, the product was separated by decantation to obtain a silicone oil. Benzoyl peroxide (RC-1, trademark, manufactured by Toray Silicone Co., Ltd.) was added to the silicone oil and kneaded at room temperature for 10 minutes using a kneading roll machine (two rolls) to prepare silicone. The degree of polymerization of the silicone was 400.

The obtained silicone was crushed by using a hammer mill while being cooled with liquid nitrogen to prepare silicone fine powder having a predetermined average particle diameter.

The silicone fine powder prepared as described above was oxidized by a thermal spraying method. The oxide layer thickness was controlled as follows. First, the treatment time was set to 0.5 seconds and the flame temperature was changed appropriately to obtain the correlation between the flame temperature and the oxide layer thickness (FIG. 1). Next, the flame temperature was controlled to a predetermined temperature to prepare the following predetermined oxide layer thickness. That is, at a flame temperature of 600 ° C, the oxide layer thickness is 1
0%, 20% at 700 ° C, 40% at 800 ° C, and 95% at 900 ° C.

100 parts by weight of the silicone fine powder having an oxide layer thickness of 20% obtained as described above was put into a Henschel mixer, and N-β (aminoethyl) γ-
20 parts by weight of a 10% by weight aqueous solution of aminopropyltrimethoxysilane (KBM603, trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) was spray-sprayed little by little. Then, it heated up at 110 degreeC, stirred for 30 minutes, and dried, and obtained the silicone fine powder (A) which has a reactive functional group on the surface. When the silanol groups were quantified by the FT-IR method, 78% of the silanol groups had disappeared as compared with those before the treatment with the silane compound.

Production Example 2 50 parts by weight of the silicone fine powder having an oxide layer thickness of 10% obtained in the above Production Example 1 was dispersed in 1,000 parts by weight of water to form a slurry, and γ-glycidoxypropyltrimethoxy was then added. Silane (KBM403, trademark, manufactured by Shin-Etsu Chemical Co., Ltd.)
0.5 parts by weight and 0.01 parts by weight of acetic acid were added with stirring. Then, it is dehydrated and dried at 120 ° C. for 2 hours to obtain a silicone fine powder (B) having a reactive functional group on the surface.
I got

Production Example 3 In a four-necked flask equipped with a reflux condenser, 100 parts by weight of methyltrimethoxysilane (SZ6070, trademark, manufactured by Toray Dow Corning Silicone Co., Ltd.) and 4 parts by weight of 50% acetic acid aqueous solution were added. Put, temperature 120 ℃, pressure 5mmH
The polymerization reaction was carried out at 5 g for 5 hours. After completion of the reaction, 130
The light components were removed from the product under the conditions of ° C and 1 mmHg to obtain silicone. The molecular weight of the silicone measured by GPC is M _n (number average molecular weight) in terms of polystyrene.
It was 28,000.

The obtained silicone was pulverized with a hammer mill under cooling with liquid nitrogen to prepare silicone fine powder having a desired particle size.

Next, the silicone fine powder was dispersed in 1,000 parts by weight of water to form a slurry, and then N-β (aminoethyl) γ-aminopropyltrimethoxysilane (KBM6
03) 0.8 parts by weight and 1,8-diaza-bicyclo-
[5.4.0] 0.5 parts by weight of undecene-7 (DBU, manufactured by San-Apro Co., Ltd.) was added, and the mixture was reacted under reflux for 2 hours. After the completion of the reaction, light components were removed from the product under the conditions of 100 ° C. and 5 mmHg to obtain a silicone fine powder (C) having a reactive functional group on the surface.

Production Example 4 Silanol group-containing dimethyl silicone (trademark SH601
8. Toray Dow Corning Silicone Co., Ltd.) was added with a catalytic amount of tin octylate, and the mixture was stirred at 160 ° C. for 5 hours for polymerization. Thereafter, it was pulverized in the same manner as in Production Example 3 and treated with a silane compound to obtain a silicone fine powder (D). However, the silane compound used was N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane (K
BM602). <Production of Resin Composition> The components used are as follows.

Resin: Cresol novolac epoxy resin (EOCN-1020, trademark, manufactured by Nippon Kayaku Co., Ltd.) Curing agent: phenol novolac (HF-1, trademark, manufactured by Meiwa Kasei Co., Ltd.) Filler: silica (spherical silica, FB) -48, Denki Kagaku Kogyo Co., Ltd. Catalyst: Triphenylphosphine (manufactured by Kitako Chemical Co., Ltd.) Coupling agent: KBM403 (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) Release agent: Fine powder carnauba (trademark, manufactured by Toa Kasei Co., Ltd.) ) Pigment: carbon black (CK45, trademark, Mitsubishi Kasei Co., Ltd.) Amount (parts by weight) of each silicone fine powder having reactive functional groups on the surface produced as described above (parts by weight), cresol novolac epoxy resin 12 parts by weight , 6 parts by weight of phenol novolac as a curing agent, 0.2 weight of triphenylphosphine as a catalyst Parts by weight, 0.8 parts by weight of coupling agent,
0.5 parts by weight of a release agent, 0.5 parts by weight of a pigment, and silica (the balance) as a filler were mixed to make 100 parts by weight as a whole. Next, the mixture was mixed with a Loedige mixer and then kneaded using a twin-screw extruder at a barrel setting temperature of 90 ° C. and a rotation speed of 200 rpm for 3 minutes to prepare pellets.
Next, the resulting pellets are heated to a cylinder temperature of 150.
C. and a mold temperature of 175.degree. C. were molded by an injection molding machine to prepare test pieces, which were used for evaluation of fluidity, coefficient of thermal expansion, elastic modulus, and interfacial adhesion. <Sealing of semiconductor element> Monitor I with simulated aluminum circuit
C (external dimensions 3 mm × 4 mm, aluminum circuit width 10 μm, gap 10 μm) was sealed by a low pressure transfer molding method using each resin composition, cured at 170 ° C. for 2 minutes, and then at 170 ° C. for 4 minutes.
The material that was cured for a period of time was used for evaluation of T / C, PCT and PCT after soldering.

The above results are shown in Table 1.

[0048]

[Table 1] * 1: Silicon fine powder having no reactive functional group on the surface (before the oxidation treatment in Production Example 1) * 2: Silicon content based on the weight of the resin composition.

In Example 1, as compared with Comparative Example 1 in which the silicone fine powder having no reactive functional group on the surface was used, the silicone fine powder was easily compounded and the flowability was good, and the interfacial adhesion was strong. It was The reliability of the semiconductor was also extremely excellent. Comparative Example 2 has a large content of silicone fine powder. Compared to Example 1, ease of blending and fine fluidity of the silicone fine powder are remarkably poor, thermal expansion coefficient is large, elastic modulus is small, and interfacial adhesion is weak. Therefore, the reliability of the semiconductor was also extremely poor. Comparative Example 3 is one in which the fine silicone powder was not mixed. Compared to Example 1, the resin composition had weak interfacial adhesion and a large elastic modulus, and the reliability of the semiconductor was significantly inferior.

In Example 2, the silicone content was determined as in Example 1.
It is an increase compared to. Although the elastic modulus was slightly lowered, the interfacial adhesion was strong and the reliability of the semiconductor was remarkably good. Example 3 uses a silicone fine powder having a reactive functional group different from the silicone fine powder used in Example 1. As in Example 1, the reliability of the semiconductor was extremely good. In Example 4, the content of fine silicone powder was increased as compared with Example 3. Although the easiness of blending and the fluidity decreased to some extent, the thermal expansion coefficient increased and the elastic modulus decreased, the interfacial adhesion was strong and the reliability of the semiconductor was sufficiently satisfactory. Example 5 uses a method different from that of Example 1, that is, a finely divided silicone powder having reactive functional groups on its surface, which is obtained by the second method. The evaluation results were the same as in Example 1, and the reliability of the semiconductor was remarkably good. Example 6 uses finely divided silicone powder having a surface to which a reactive functional group has been added by the third method. The evaluation results were the same as in Example 1, and the reliability of the semiconductor was remarkably good.

[0051]

The present invention provides a highly reliable encapsulating resin composition having a small internal stress and excellent interfacial adhesion.

[Brief description of drawings]

FIG. 1 is a graph showing the correlation between flame temperature and oxide layer thickness of fine silicone powder.

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Claims (5)

[Claims] 1. A resin composition for encapsulation, comprising a fine silicone powder having a reactive functional group on its surface. 2. The average particle diameter D _{50 of the} silicone fine powder is 0.0.
The resin composition according to claim 1, which has a thickness of 2 to 200 μm. 3. The resin composition according to claim 1 or 2, which contains the silicone fine powder in an amount of 0.1 to 90% by weight based on the weight of the resin composition. 4. The reactive functional group is at least one group selected from the group consisting of epoxy group, alkoxy group, silanol group, SiH group, amino group, hydroxyl group, mercapto group, vinyl group and methacryloxy group. Item 1
The resin composition according to any one of 3 above. 5. The resin composition according to any one of claims 1 to 4, wherein the finely divided silicone powder is obtained by modifying a silicone having a silanol group on the surface with a silane coupling agent.