CURABLE SILICONE COMPOSITION, CURED PRODUCT OF SAME, AND METHOD FOR PRODUCING SAME

Abstract

Provided is a curable silicone composition and uses thereof. The composition which has hot-melt properties, strongly adheres to poorly adhesive substrates, and is particularly superior in flexibility and toughness at high temperatures from room temperature to approximately 150° C. in cured products such as overmolding, in addition to providing a cured product that does not easily warp or become damaged even when integrally molded with a lead frame or the like. The composition comprises: (A) organopolysiloxane resin microparticles where 20 mol % or more of all siloxane units is siloxane units represented by RSiO.sub.3/2 where R is a monovalent hydrocarbon group; (B) a silatrane derivative or a carbasilatrane derivative; (C) a curing agent; and (D) a functional inorganic filler. The content of component (D) is 50% or more by volume relative to the overall composition. The composition is solid at 25° C. and has hot-melt properties at a temperature of 200° C. or lower.

Claims

1. A curable silicone composition that is solid at 25° C. and has hot-melt properties at a temperature of 200° C. or lower, comprising: (A) organopolysiloxane resin microparticles where 20 mol % or more of all siloxane units is siloxane units represented by RSiO.sub.3/2 where R is a monovalent hydrocarbon group; (B) one or more adhesion promoter agents selected from a silatrane derivative and a carbasilatrane derivative; (C) a curing agent; and (D) functional inorganic filler; wherein the content of component (D) is 50% or more by volume relative to the overall composition.

2. The curable silicone composition according to claim 1, wherein at least part or all of component (A) is (Al) hot-melt organopolysiloxane resin microparticles which have a softening point of 30° C. or higher, have at least one curing reactive functional group containing a carbon-carbon double bond per molecule, and where 20 mol % or more of all siloxane units is siloxane units represented by RSiO.sub.3/2 where R is a monovalent hydrocarbon group.

3. The curable silicone composition according to claim 1, wherein: the content of component (B) is within a range of 0.1 to 1.0 mass % relative to the overall composition.

4. The curable silicone composition according to claim 1, wherein curing thereof provides a cured product having an average linear expansion coefficient of 20 ppm/° C. or less within a range of 25° C. to 200° C.

5. The curable silicone composition according to claim 1, wherein curing thereof provides a cured product having a bending strength of 15 MPa or more as determined by the method prescribed in JIS K 6911-1995.

6. The curable silicone composition according to claim 1, wherein at least some or all of component (A) is (A1-1) hot-melt organopolysiloxane resin microparticles which have a softening point of 30° C. or higher, have at least one curing reactive functional group containing a carbon-carbon double bond per molecule, and where 20 mol % or more of all siloxane units is siloxane units represented by RSiO.sub.3/2 where R is a monovalent hydrocarbon group, and wherein 10 mol % or more of the silicon atom-bonded organic groups are aryl groups.

7. The curable silicone composition according to claim 1, wherein component (B) is one or more selected from: a carbasilatrane derivative renresented by the following structural formula (1): ##STR00008## R.sup.1 is the same or different hydrogen atom or alkyl group, R.sup.2 is the same or different group selected from a hydrogen atom, an alkyl group, and an alkoxysilyl group-containing organic group represented by the general formula: R.sup.4—Si(OR.sup.5).sub.xR.sup.6.sub.(3-x) where R.sup.4 is a divalent organic group, R.sup.5 is an alkyl group having 1 to 10 carbon atoms, R.sup.6 is a substituted or unsubstituted monovalent hydrocarbon group, and x is 1, 2, or 3, provided that at least one of R.sup.2 is this alkoxysilyl group-containing organic group, and R.sup.3 is a group selected from a substituted or unsubstituted monovalent hydrocarbon group, an alkoxy group having 1 to 10 carbon atoms, a glycidoxyalkyl group, an oxiranylalkyl group, an acyloxyalkyl groups, or an alkenyl group; and a carbasilatrane derivative represented by the following structural formula (2): ##STR00009## where R.sup.1 is an alkyl group, an alkenyl group or an alkoxy group, while R.sup.2 is the same or different group selected from the group consisting of groups represented by the general formula: ##STR00010## where R.sup.4 is an alkylene group or alkyleneoxyalkylene group, R.sup.5 is a monovalent hydrocarbon group, R.sup.6 is an alkyl group, and a is 0, 1, or 2, and
[Formula 4]
—R.sup.7—O—R.sup.8  (4) where R.sup.7 is an alkylene group, R.sup.8 is an alkyl group, alkenyl group, or acyl group, and R.sup.3 is the same or different hydrogen atom or alkyl group.

8. The curable silicone composition according to claim 1, wherein component (A) is spherical resin microparticles having an average primary particle diameter of 1 to 10 μm.

9. The curable composition according to claim 1, wherein component (C) is one or more curing agents selected from (c1) or (c2) below, in an amount necessary to cure the composition: (c1) an organic peroxide; and (c2) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule and a hydrosilylation reaction catalyst.

10. The curable silicone composition according to claim 1, wherein component (D) is selected from the group consisting of a reinforcing filler, a white pigment, a thermally conductive filler, an electrically conductive filler, a phosphor, and a mixture of at least two of these.

11. The curable silicone composition according to claim 1, in a granule, a pellet, or a sheet form.

12. A substantially flat, 10 to 1,000 μm thick, curable silicone composition sheet formed from the curable silicone composition according to claim 1.

13. A film-like adhesive, comprising the curable silicone composition sheet according to claim 12.

14. A releasable laminate, comprising: the curable silicone composition sheet according to claim 12; and a sheet-like substrate with a release surface facing the curable silicone composition sheet on one or both surfaces of the curable silicone composition sheet.

15. A cured product obtained by curing the curable silicone composition according to claim 1.

16. A semiconductor device or a member for a semiconductor device, the semiconductor device or member thereof comprising the cured product according to claim 15.

17. (canceled)

18. A method for manufacturing the curable silicone composition according to claim 1, wherein each component that makes up the curable silicone composition is granulated by mixing under temperature conditions not exceeding 50° C.

19. A method for molding a cured product, comprising the following steps: (I) heating the curable silicone composition in the form of pellets or sheets according to claim 11 to a temperature of 100° C. or higher to melt; (II) injecting the curable silicone composition in a liquid state obtained in step (I) into a mold or distributing the curable silicone composition obtained in the step (I) to a mold by clamping; and (III) curing the curable silicone composition injected or distributed in step (II).

20. A method for molding a cured product, comprising a coating process for overmolding and underfilling a semiconductor device using a cured product formed from the curable silicone composition according to claim 1; optionally, the method comprising: covering a surface of a semiconductor wafer substrate on which a single or plurality of semiconductor devices are mounted with a cured product produced by curing the curable silicone composition; and overmolding so that a gap between the semiconductor devices is filled with the cured product.

21. (canceled)

22. A method for manufacturing the curable silicone composition sheet according to claim 12, comprising the followings steps: 1) mixing raw material components of the curable silicone composition at a temperature of 50° C. or higher; 2) kneading a mixture obtained in step 1) while heating and melting; 3) laminating a heated and melted mixture obtained in step 2) between films provided with at least one release surface; and 4) extending a laminate body obtained in step 3) between rollers to mold a curable silicone sheet having a specific film thickness.

Description

EXAMPLES

[0212] The hot-melt curable silicone composition of the present invention and manufacturing method thereof are described in detail by means of examples and comparative examples. Note that, in the formulas, Me, Ph, and Vi represent a methyl group, a phenyl group, and a vinyl group, respectively. Moreover, the softening points and melt viscosity of the curable silicone compositions of each example and comparative example were determined by the methods described below. The curable silicone composition was heated at 180° C. for 2 hours to produce a cured product, with the adhesion to various substrates determined by the methods described below. The results are shown in Table 1.

[0213] [Softening Point of Curable Silicone Composition]

[0214] The curable silicone composition was molded into cylindrical pellets of φ14 mm×22 mm. The pellet was placed on a hot plate set at 25° C. to 100° C. and kept pressed from above for 10 seconds with a load of 100 grams, and after the load was removed, the amount of deformation of the pellet was measured. The temperature at which the deformation amount in the height direction was 1 mm or more was defined as the softening point.

[0215] [Melt Viscosity]

[0216] The melt viscosity of the curable silicone composition at 180° C. was measured using a nozzle having a diameter of 0.5 mm under 100 kgf of pressure with a CFT-500EX Koka-type flow tester (manufactured by the Shimadzu Corporation).

[0217] [Bending Strength of Cured Product]

[0218] The curable silicone composition was heated at 180° C. for 2 hours to prepare a cured product. The bending strength of the cured product was determined by the method prescribed in JIS K 6911-1995 “General Testing Method for Thermosetting Plastics”.

[0219] [Linear Expansion Coefficient Curve of Cured Product]

[0220] The curable silicone composition of Example 1 was cured by the method described above to prepare a cured product. The linear expansion coefficient of the cured product was determined by TM9200 manufactured by Advance Riko, Inc. in a temperature range of 20° C. to 200° C.

[0221] [Die Shear Strength]

[0222] A curable silicone composition was placed at four locations, each approximately 500 mg, on various substrates of 25 mm×75 mm. Next, the composition was covered with a 10 mm square glass chip having a thickness of 1 mm, then heated and cured for two hours under thermocompression bonding using a 1 kg plate at a temperature of 180° C. Thereafter, the mixture was cooled to room temperature and the die shear strength was determined using a shear strength determination apparatus (bond tester SS-100KP, available from Seishin Trading Co., Ltd.)

[0223] Organopolysiloxane resins containing a hydrosilylation reaction catalyst were prepared by the methods shown in Reference Examples 1 to 3 below and the hot-melt properties thereof were evaluated by the presence or absence of softening point/melt viscosity. Moreover, the organopolysiloxane resin microparticles were also prepared by the method shown in Reference Example 4. In the reference examples, the 1,1,3,3-tetramethyl-1,3-divinyl disiloxane used for the platinum complex that is the hydrosilylation reaction catalyst is described as “1,3- divinyltetramethyldisiloxane”.

Reference Example 1

[0224] A toluene solution of a resinous organopolysiloxane (1) containing 10 ppm of platinum metal in mass units was prepared by injecting 270.5 g of a 55 mass % toluene solution of a resinous organopolysiloxane represented by the average unit formula:

(PhSiO.sub.3/2).sub.0.80(Me.sub.2ViSiO.sub.1/2).sub.0.20,

which is a white solid at 25° C., along with 0.034 g of a 1,3-divinyltetramethyldisiloxane solution of platinum 1,3-divinyltetramethyldisiloxane complex (platinum metal content=approximately 4000 ppm) into a 1 L flask and stirring uniformly at room temperature (25° C.). The softening point of this resinous organopolysiloxane (1) was 100° C., with a melt viscosity determined at 150° C. using a rotary viscometer was 30 Pa.Math.s.

Reference Example 2

[0225] A toluene solution of a resinous organopolysiloxane (2) containing 10 ppm of platinum metal in mass units was prepared by injecting 270.5 g of a 55 mass % toluene solution of a resinous organopolysiloxane represented by the average unit formula:

(PhSiO.sub.3/2).sub.0.80(Me.sub.2ViSiO.sub.1/2).sub.0.20,

which is a white solid at 25° C., 21.3 g of a diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups and having a viscosity of 5 mPa.Math.s (silicon-atom bonded hydrogen atom content=0.6 mass %) represented by the formula:

HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

(in an amount such that the amount of silicon atom-bonded hydrogen atoms in this component is 0.5 mol relative to 1 mol of vinyl groups in the resinous organopolysiloxane), along with 0.034 g of a 1,3-divinyltetramethyldisiloxane solution of platinum 1,3-divinyltetramethyldisiloxane complex (platinum metal content=approximately 4000 ppm) (in an amount such that the amount of platinum metal is 10 ppm in mass units with respect to this liquid mixture) into a 1 L flask and stirring uniformly at room temperature. Thereafter, the temperature in the flask was raised to 100° C. using an oil bath and the mixture was stirred under a reflux of toluene for 2 hours to prepare a toluene solution of an organosiloxane crosslinked product (2) containing a resinous organosiloxane derived from the above-mentioned resinous organopolysiloxane and a chained organosiloxane derived from the above-mentioned diphenylsiloxane and having a vinyl group not involved in the above-mentioned reaction. Note that when the organosiloxane crosslinked product (2) was analyzed by FT-IR, peaks of silicon atom-bonded hydrogen atom were not observed. Moreover, the softening point of this organosiloxane crosslinked product (2) was 75° C., while the melt viscosity thereof at 100° C. was 700 Pa.Math.s.

Reference Example 3

Hot-Meltable Organopolysiloxane Resin Microparticles (1)

[0226] True-spherical hot-melt silicone microparticles (1) were prepared by atomizing the toluene solution of the organosiloxane crosslinked product (1) prepared in Reference Example 1 by spray drying at 40° C. while removing toluene. Observation of the microparticles with an optical microscope revealed that the particle diameter was 5 to 10 μm and the average particle diameter was 7.9 μm.

Reference Example 4

Hot-Meltable Organopolysiloxane Resin Microparticles (2)

[0227] True-spherical hot-melt silicone microparticles (2) were prepared by atomizing the toluene solution of the organosiloxane crosslinked product (2) prepared in Reference Example 2 by spray drying at 40° C. while removing toluene. Observation of the microparticles with an optical microscope revealed that the particle diameter was 5 to 10 μm and the average particle diameter was 7.5 μm.

Example 1

[0228] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1), [0229] 8.1 g of bis(trimethoxysilyl propoxymethyl)vinyl silatrane, and [0230] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Example 2

[0231] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0232] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0233] 8.1 g of bis(trimethoxysilyl propoxymethyl)allyl silatrane, and

[0234] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Example 3

[0235] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were injected as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %) and represented by

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0236] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1), and

[0237] 8.1 g of a carbasilatrane derivative represented by the following structural formula:

##STR00007##

as well as 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Example 4

[0238] First, 1700.0 g of fused silica having an average particle diameter of 14.5 μm (S610-5P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 125 mPa.Math.s represented by the formula:

Me.sub.3SiO(Me.sub.2SiO).sub.110Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0239] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0240] 8.0 g of bis(trimethoxysilyl propoxymethyl)vinyl silatrane, and

[0241] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Example 5

[0242] First, 1700.0 g of fused silica having an average particle diameter of 14.5 μm (S610-5P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 125 mPa.Math.s represented by the formula:

Me.sub.3SiO(Me.sub.2SiO).sub.110Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0243] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0244] 8.0 g of bis(trimethoxysilyl propoxymethyl)allyl silatrane, and

[0245] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Example 6

[0246] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (SP-6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute and repeated 5 times at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C.

[0247] Next, 74.1 g of hot-melt silicone microparticles (2), 11.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups and having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %) represented by the formula:

HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

and 14.8 g of a methylphenylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups and having a viscosity of 1,000 Pa.Math.s (vinyl group content=2.1 mass %) represented by the average formula

Me.sub.2ViSiO(MePhSiO).sub.17.5SiMe.sub.2Vi,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane is 1.0 mol relative to 1 mol of vinyl groups in the silicone microparticles (1) and the methylphenylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups,

[0248] 8.1 g of bis(trimethoxysilyl propoxymethyl)vinyl silatrane, and

[0249] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) was batch fed into a small grinder and stirred for 1 minute at room temperature (25° C.) to prepare a uniform white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Comparative Example 1

[0250] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0251] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0252] 8.1 g of a condensation reaction product of 3-glycidoxypropyl trimethoxysilane and methylvinyl siloxane oligomer blocked by a silanol group at both terminals of a molecular chain with a viscosity of 30 mPa.Math.s at 25° C., and

[0253] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Comparative Example 2

[0254] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by the formula:

HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0255] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1), and 8.1 g of an epoxy group-containing polysiloxane:

(Me.sub.2ViSiO.sub.1/2).sub.0.2(MeEpSiO.sub.2/2).sub.0.25(PhSiO.sub.3/2).sub.0.55(HO.sub.1/2).sub.0.005

as well as 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into a small grinder and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Comparative Example 3

[0256] First, 1900.0 g of fused silica having an average particle diameter of 17 μm (S6050P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 23 mPa.Math.s represented by the formula:

Me.sub.2ViSiO(Me.sub.2SiO).sub.29Si(OMe).sub.3

were injected as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by

Formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0257] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0258] 8.1 g of 3-glycidoxypropyltrimethoxysilane, and

[0259] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

Comparative Example 4

[0260] First, 1700.0 g of fused silica having an average particle diameter of 14.5 μm (S610-5P manufactured by Nippon Steel Materials, Inc.) and 9.5 g of dimethylpolysiloxane having a viscosity of 125 mPa.Math.s represented by the formula:

Me.sub.3SiO(Me.sub.2SiO).sub.110Si(OMe).sub.3

were placed as a single batch into a small pulverizer and stirred for 1 minute at 150° C., then, once the fused silica was surface-treated, the temperature of the pulverizer was returned to 25° C. Next, 78.7 g of hot-melt silicone microparticles (1), 9.1 g of diphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups having a viscosity of 5 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.6 mass %), and represented by the formula: HMe.sub.2SiO(Ph.sub.2SiO)SiMe.sub.2H,

[0261] 12.2 g of a branched-chain organopolysiloxane having two or more silicon atom-bonded hydrogen atoms in each molecule and having a viscosity of 25 mPa.Math.s (silicon atom-bonded hydrogen atom content=0.65 mass %) represented by Average unit formula:

(PhSiO.sub.3/2).sub.0.4(HMe.sub.2SiO.sub.1/2).sub.0.6,

which is an amount where the silicon atom-bonded hydrogen atoms in the diphenylsiloxane and branched chain phenylsiloxane is 1.0 mol relative to 1.0 mol of vinyl groups in the silicone microparticles (1),

[0262] 8.1 g of N-phenyl-3-aminopropyltrimethoxysilane, and

[0263] 1-ethynyl-1-cyclohexanol (an amount of 300 ppm in mass units relative to this composition) were additionally fed into the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniform granular white curable silicone composition. The measurement results of the softening point and other properties of this composition are shown in Table 1.

TABLE-US-00001 TABLE 1 Examples 1 2 3 4 5 6 Softening temperature [° C.] 100 100 85 90 90 85 Melt viscosity [Pas] 65 70 65 75 80 150 Die shear To Al [MPa] 9.3 10.1 8.5 9.1 9.6 5.3 strength To Ni [MPa] 8.3 9.5 7.1 7.9 8.3 5.1 To Au [MPa] 7.9 9.1 6.5 8.0 8.5 5.2 To epoxy glass [MPa] 9.1 10.2 8.6 8.5 8.8 5.2 CTE [ppm/° C.] 12 11 12 13 14 12 Bending strength [MPa] 46 51 43 48 49 52 Comparative Examples 1 2 3 4 Softening temperature [° C.] 100 100 110 110 Melt viscosity [Pas] 70 85 250 190 Die shear To Al [MPa] 7.5 7.9 8.9 8.1 strength To Ni [MPa] 0 0 4.2 3.7 To Au [MPa] 0 0 3.1 3.3 To epoxy glass [MPa] 2.1 1.4 4.3 3.2 CTE [ppm/° C.] 11 12 10 14 Bending strength [MPa] 49 50 37 35

SUMMARY

[0264] The curable silicone composition of Practical Example 1 to 6 according to the present invention had good hot-melt properties, strongly adhered to any substrate, and had a sufficient linear expansion coefficient (CTE) and bending strength sufficient for practical use. Therefore, it is expected that the cured products obtained using these curable silicone compositions can be suitably used in sealing semiconductor devices in which gold, epoxy glass, etc. are often used.

[0265] In contrast, Comparative Examples 1 to 4, which did not satisfy the compositional requirements of the present invention, exhibited good adhesion to aluminum, but did not strongly adhere to nickel, gold, and epoxy glass, which are relatively adhesion-poor substrates. Moreover, when a silane compound other than a silatrane derivative such as that in Comparative Examples 3 and 4 was used, the melt characteristics as well as the strength of the cured product deteriorated. This is considered to be the result of the adhesion promoter in Comparative Examples 3 and 4 adversely affecting the surface treatment of the functional filler.

Manufacturing Example 1

[0266] The granular curable silicone composition, such as Example 1 above, was heated to 80° C., heat-melted and mixed using a twin-screw extruder, and kneaded into the form of a semi-solid softened material, then fed onto a releasable film (Biwa liner manufactured by Takara Inc.) at a feed rate of 5 kg/hour and laminated between the two releasable films. The laminate was then extended between rolls to form a laminate in which a hot-melt curable silicone sheet having a thickness of 500 μm is laminated between two releasable films, after which the entire laminate was cooled by a cooling roll set at −15° C. In this laminate, a flat and homogeneous hot-melt curable silicone sheet was obtained by separating the releasable film.

Manufacturing Example 2

[0267] The granular curable silicone compositions of Example 1 and the like described above were heated to 80° C., heat-melted and mixed using a twin-screw extruder, and formed into a sheet shape using a T-type die (opening dimensions: 800 μm×100 mm, heated to 80° C.), then fed onto a releasable film (Biwa liner manufactured by Takara Inc.) at a supply speed of 5 kg/hr. The entire sheet was cooled by a cooling roll set at −15° C., then laminated between the two releasable films. The laminate was then extended between rolls to form a laminate in which a hot-melt curable silicone sheet having a thickness of 500 μm is laminated between two releasable films. In said laminate, a flat and homogeneous hot-melt curable silicone sheet was obtained by separating the releasable film.