Thermal conductive silicone composition and semiconductor device

1. A semiconductor device comprising: a heat-generating electronic part; and a heat dissipator,

wherein a thermal conductive silicone composition comprising

(A) an organopolysiloxane that exhibits a kinetic viscosity of 10 to 100,000 mm 2 /s at 25° C., and is represented by the following average composition formula (1)

R 1 a SiO (4-a)/2   (1)

wherein R 1 represents a hydrogen atom or at least one group selected from a hydroxy group and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a satisfies 1.8≦a≦2.2; and

(B) a silver powder having a tap density of not lower than 3.0 g/cm 3 and a specific surface area of not larger than 2.0 m 2 /g, said silver powder being in an amount of 300 to 11,000 parts by mass with respect to 100 parts by mass of the component (A)

is interposed between said heat-generating electronic part and said heat dissipator.

2. A manufacturing method of a semiconductor device, comprising:

a step of heating a thermal conductive silicone composition to a temperature of not lower than 80° C. under a pressure of not lower than 0.01 MPa, with the thermal conductive silicone composition being interposed between a heat-generating electronic part and a heat dissipator, wherein the thermal conductive silicone composition comprises:

(A) an organopolysiloxane that exhibits a kinetic viscosity of 10 to 100,000 mm 2 /s at 25° C., and is represented by the following average composition formula (1)

R 1 a SiO (4-a)/2   (1)

wherein R 1 represents a hydrogen atom or at least one group selected from a hydroxy group and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a satisfies 1.8≦a≦2.2; and

(B) a silver powder having a tap density of not lower than 3.0 g/cm 3 and a specific surface area of not larger than 2.0 m 2 /g, said silver powder being in an amount of 300 to 11,000 parts by mass with respect to 100 parts by mass of the component (A).

3. The semiconductor device according to claim 1 , wherein an aspect ratio of said silver powder as the component (B) is 2.0 to 150.0.

4. The semiconductor device according to claim 1 , wherein the entire or a part of the component (A) comprises:

(C) an organopolysiloxane containing in one molecule at least two silicon-bonded alkenyl groups; and/or

(D) an organohydrogenpolysiloxane containing in one molecule at least two silicon-bonded hydrogen atoms.

5. The semiconductor device according to claim 3 , wherein the entire or a part of the component (A) comprises:

(C) an organopolysiloxane containing in one molecule at least two silicon-bonded alkenyl groups; and/or

(D) an organohydrogenpolysiloxane containing in one molecule at least two silicon-bonded hydrogen atoms.

6. The semiconductor device according to claim 1 , wherein the thermal conductive silicone composition further comprises a curing catalyst.

7. The semiconductor device according to claim 3 , wherein the thermal conductive silicone composition further comprises a curing catalyst.

8. The semiconductor device according to claim 4 , wherein the thermal conductive silicone composition further comprises a curing catalyst.

9. The semiconductor device according to claim 5 , wherein the thermal conductive silicone composition further comprises a curing catalyst.

10. The semiconductor device according to claim 1 , wherein the thermal conductive silicone composition further comprises:

(E) an organosilane that is in an amount of 0 to 10 parts by mass with respect to 100 parts by mass of the component (A), and is represented by the following general formula (2)

R 2 b Si(OR 3 ) 4-b   (2)

wherein R 2 represents at least one group selected from the group consisting of: a saturated or unsaturated monovalent hydrocarbon group that may have a substituted group; an epoxy group; an acrylic group; and a methacrylic group, R 3 represents a monovalent hydrocarbon group, and b satisfies 1≦b≦3.

11. The semiconductor device according to claim 3 , wherein the thermal conductive silicone composition further comprises:

(E) an organosilane that is in an amount of 0 to 10 parts by mass with respect to 100 parts by mass of the component (A), and is represented by the following general formula (2)

R 2 b Si(OR 3 ) 4-b   (2)

wherein R 2 represents at least one group selected from the group consisting of: a saturated or unsaturated monovalent hydrocarbon group that may have a substituted group; an epoxy group; an acrylic group; and a methacrylic group, R 3 represents a monovalent hydrocarbon group, and b satisfies 1≦b≦3.

12. The semiconductor device according to claim 4 , wherein the thermal conductive silicone composition further comprises:

(E) an organosilane that is in an amount of 0 to 10 parts by mass with respect to 100 parts by mass of the component (A), and is represented by the following general formula (2)

R 2 b Si(OR 3 ) 4-b   (2)

wherein R 2 represents at least one group selected from the group consisting of: a saturated or unsaturated monovalent hydrocarbon group that may have a substituted group; an epoxy group; an acrylic group; and a methacrylic group, R 3 represents a monovalent hydrocarbon group, and b satisfies 1≦b≦3.

13. The semiconductor device according to claim 5 , wherein the thermal conductive silicone composition comprises:

(E) an organosilane that is in an amount of 0 to 10 parts by mass with respect to 100 parts by mass of the component (A), and is represented by the following general formula (2)

R 2 b Si(OR 3 ) 4-b   (2)

wherein R 2 represents at least one group selected from the group consisting of: a saturated or unsaturated monovalent hydrocarbon group that may have a substituted group; an epoxy group; an acrylic group; and a methacrylic group, R 3 represents a monovalent hydrocarbon group, and b satisfies 1≦b≦3.