Curable organopolysiloxane composition and semiconductor device
A curable organopolysiloxane composition comprising (A) a linear organopolysiloxane having at least two alkenyl groups and at least one aryl group per molecule, (B) a branched organopolysiloxane having at least one alkenyl group and at least one aryl group per molecule, and having siloxane units represented by the general formula: RsiO 2/3 , (C) a linear organopolysiloxane with both terminal ends of the molecular chain blocked by silicon bonded hydrogen atoms having at least one aryl group per molecule, and (D) a hydrosilation reaction catalyst, and a semiconductor device whose semiconductor elements are coated with the cured product of the above-described composition. The curable organopolysiloxane composition shows low viscosity, excellent filling properties, and excellent curability that cures to form a soft cured product of a large refractive index, high light transmittance, and high adhesion to substrates, as well as the semiconductor device shows superior reliability.
1. A curable organopolysiloxane composition comprising;
(A) a linear organopolysiloxane having at least two silicon bonded alkenyl groups and at least one silicon bonded aryl group per molecule, in which the content of the silicon bonded aryl groups relative to all the silicon bonded organic groups in component (A) is not less than 40 mol %,
(B) a branched organopolysiloxane having at least one silicon bonded alkenyl group and at least one silicon bonded aryl group per molecule, and having siloxane units represented by the general formula:
RSiO 3/2 ,
where R is a substituted or unsubstituted monovalent hydrocarbon group and where component (B) is present in an amount necessary for a weight ratio of from 1/99 to 99/1 relative to component (A),
(C) a linear organopolysiloxane with both terminal ends of the molecular chain blocked by silicon bonded hydrogen atoms having at least one silicon bonded aryl group per molecule, where component (C) is present in an amount necessary to provide 1 to 200 parts by weight relative to 100 parts by weight of the total of component (A) and component (B), and
(D) a hydrosilation reaction catalyst present in an amount necessary to promote the curing of the present composition.
2. The curable organopolysiloxane composition according to claim 1 , in which component (A) is an organopolysiloxane represented by the general formula:
where R 1 is a substituted or unsubstituted monovalent hydrocarbon group with at least two R 1 being alkenyl groups and at least one R 1 being an aryl group, and <<m>> is an integer of 5 to 1000.
3. The curable organopolysiloxane composition according to claim 1 , in which component (B) is an organopolysiloxane represented by the average unit formula:
(R 2 SiO 3/2 ) a (R 2 2 SiO 2/2 ) b (R 2 3 SiO 1/2 ) c (SiO 4/2 ) d (XO 1/2 ) e
where R 2 is a substituted or unsubstituted monovalent hydrocarbon group with the range of from 0.1 to 40 mol % of R 2 constituted by alkenyl groups and not less than 10 mol % of R 2 constituted by aryl groups, X is a hydrogen atom or alkyl group, <<a>> is a positive number, <<b>> is 0 or a positive number, <<c>> is 0 or a positive number, <<d>> is 0 or a positive number, <<e>> is 0 or a positive number, <<b/a>> is a number between 0 and 10, <<c/a>> is a number between 0 and 0.5, <<d/(a+b+c+d)>> is a number between 0 and 0.3, and <<e/(a+b+c+d)>> is a number between 0 and 0.4.
4. The curable organopolysiloxane composition according to claim 1 , in which component (C) is an organopolysiloxane represented by the general formula:
where R 3 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group with the exception of alkenyl groups and at least one R 3 is an aryl group, and <<n>> is an integer of 1 or more.
5. The curable organopolysiloxane composition according to claim 1 , which cures to form a cured product with a refractive index at 25° C. of 1.5 or more for visible light with a wavelength of 589 nm.
6. The curable organopolysiloxane composition according to claim 1 , which cures to form a cured product with a light transmittance at 25° C. of not less than 80%.
7. The curable organopolysiloxane composition according to claim 1 , which cures to form a cured product with a needle penetration score of not less than 5.
8. A semiconductor device, in which semiconductor elements are coated with a cured product of the curable organopolysiloxane composition according to claim 1 .
9. The semiconductor device according to claim 8 , in which the semiconductor elements are light-emitting elements.
10. A semiconductor device, in which semiconductor elements are coated with a cured product of the curable organopolysiloxane composition according to claim 2 .
11. A semiconductor device, in which semiconductor elements are coated with a cured product of the curable organopolysiloxane composition according to claim 3 .
12. A semiconductor device, in which semiconductor elements are coated with a cured product of the curable organopolysiloxane composition according to claim 4 .