Curable organopolysiloxane composition and semiconductor device

1. A curable organopolysiloxane composition, wherein, in its cured state and under conditions that the temperature is 25° C. and the humidity is 60% RH, the composition has a tensile strength of 2 to 8 Mpa, an elongation at break of 35% to 100%, and an index of refraction being equal to or greater than 1.45, the composition comprises:

(A) organopolysiloxane comprising an R 1 3 SiO 1/2 unit, an R 2 2 SiO 2/2 unit and an R 3 SiO 3/2 unit, wherein R 1 is selected from similar or different alkenyl groups, univalent substituted or unsubstituted hydrocarbonyls which do not contain any aromatic hydrocarbon and aliphatic unsaturated bond, R 2 is selected from similar or different alkenyl groups, aromatic groups, univalent substituted or unsubstituted hydrocarbonyls which do not contain any aromatic hydrocarbon and aliphatic unsaturated bond, and R 3 is an aromatic group; wherein the content of the aromatic group is larger than 10 mol % and the content of alkenyl groups is larger than 0.1 mol/100 g;

(B) branched polyorganohydrogensiloxane having the viscosity of 300 to 4000 mPa·s, wherein each molecule has on average at least three silicon-bonded hydrogen atoms and at least one aromatic group, and the content of the aromatic group is larger than 10 mol %;

(C) a hydrosilylation catalyst having the content capable of facilitating curing of the composition.

2. The curable organopolysiloxane composition according to claim 1 , wherein, the component (B) comprising R 4 3 SiO 1/2 unit, an R 5 SiO 3/2 unit, wherein, R 4 is selected from similar or different univalent substituted or unsubstituted hydrocarbyl and hydrogen atoms, which do not contain any aromatic hydrocarbon and aliphatic unsaturated bond, and R 5 is an aromatic group.

3. The curable organopolysiloxane composition according to claim 2 , wherein, the component (B) has the following average unit formula,

(R 5 SiO 3/2 ) b1 (R 4 3 SiO 1/2 ) b3 ,

Wherein R 4 is selected from similar or different alkyl groups and hydrogen atoms, which are univalent substituted or unsubstituted, R 5 is an aromatic group, wherein, 0.5<b1<0.9, 0.1<b3<0.5, b1+b3=1.

4. The curable organopolysiloxane composition according to claim 2 , wherein, the component (B) has the following average unit formula,

(R 5 SiO 3/2 ) b1 (R 4 3 SiO 1/2 ) b31 (R 4 2 HSiO 1/2 ) b32 ,

Wherein R 4 is s univalent substituted or unsubstituted alkyl, R 5 is a phenyl, wherein, 0.5<b1<0.9, 0.1<b31<0.4, 0.1<b32<0.5, and b1+b31+b32=1.

5. The curable organopolysiloxane composition according to claim 1 , wherein, the composition further comprising component (A′), the component (A′) comprises R 1 3 SiO 1/2 unit and the R 3 SiO 3/2 unit, R 1 is selected from similar or different alkenyl groups, univalent substituted or unsubstituted hydrocarbonyls which do not contain any aromatic hydrocarbon and aliphatic unsaturated bond, and R 3 is an aromatic group; wherein the content of the aromatic group is larger than 10 mol % and the content of alkenyl groups is larger than 0.1 mol/100 g, wherein component (A) has a viscosity that is less than 15000 mPa·s at 25° C., and component (A′) has a viscosity that is more than 15000 mPas at 25° C., the weight ratio of the component (A′) to the component (A) is 100: (20-500).

6. The curable organopolysiloxane composition according to claim 5 , wherein, the component (A′) has the following average unit formula,

(R 3 SiO 3/2 ) a′1 (R 1 3 SiO 1/2 ) a′3 ,

Wherein R 1 is selected from similar or different alkenyl groups, univalent substituted or unsubstituted alkyl, R 3 is an aromatic group, wherein, 0.1<a1<0.9, 0.1<a′3<0.9, and a′1+a′3=1.

7. The curable organopolysiloxane composition according to claim 1 , wherein, the molar ratio of the silicon-bonded hydrogen atoms in the component (B) to the alkenyl groups in the component (A) is 0.9-2.0.

8. The curable organopolysiloxane composition according to claim 1 , wherein, the weight ratio of the component (A) to the component (B) range from 1:99 to 99:1.

9. The curable organopolysiloxane composition according to claim 1 , wherein, the component (A) has the following average unit formula,

(R 3 SiO 3/2 ) a1 (R 2 2 SiO 2/2 ) a2 (R 1 3 SiO 1/2 ) a3 ,

Wherein R 1 is selected from similar or different alkenyl groups, univalent substituted or unsubstituted alkyl, R 2 is selected from similar or different alkenyl groups, alkyl and aromatic groups that are univalent substituted or unsubstituted, R 3 is an aromatic group, wherein 0.1<a1<0.8, 0.1<a2<0.6, 0.02<a3<0.5, a1+a2+a3=1.

10. The curable organopolysiloxane composition according to claim 1 , wherein, the component (A) has the following average unit formula,

(R 3 SiO 3/2 ) a1 (R 21 2 SiO 2/2 ) a21 (R 21 R 22 SiO 2/2 ) a22 (R 1 3 SiO 1/2 ) a3 ,

Wherein R 1 is selected from similar or different alkenyl groups, univalent substituted or unsubstituted alkyl, R 21 is a phenyl, and R 22 is a univalent substituted or unsubstituted alkyl, R 3 is an aromatic group, wherein, 0.1<a1<0.8, 0.1<a21<0.4, 0<a22<0.2, 0.02<a3<0.5, a1+a21+a22+a3=1.

11. A semiconductor device comprising a light-emitting component and a support configured to fix the light-emitting component, wherein, the light-emitting component is coated with the cured substance of the curable organopolysiloxane composition of claim 1 .