Semiconductor encapsulation material and method for encapsulating semiconductor using the same
A semiconductor encapsulation material of the present invention contains a glass for metal coating which has a strain point of 480° C. or higher, a temperature corresponding to a viscosity of 10 4 dPa·s of 1,100° C. or lower, and a thermal expansion coefficient at 30 to 380° C. of 70×10 −7 to 110×10 −7 /° C. The semiconductor encapsulation material of the present invention contains no environmentally harmful substances, has a heat resistance temperature as high as 500° C. or above, and can be used for the encapsulation of metals susceptible to oxidation, e.g., Dumet.
1. A semiconductor encapsulation material comprising a glass for metal encapsulation which has a strain point of 480° C. or higher, a temperature corresponding to a viscosity of 10 4 dPa·s of 1,100° C. or lower, and a thermal expansion coefficient at 30 to 380° C. of 70×10 −7 to 110×10 −7 /° C., wherein content of B 2 O 3 in the glass for metal encapsulation is 5 to 21% by mole.
2. The semiconductor encapsulation material according to claim 1 , wherein the glass for metal encapsulation is composed of an SiO 2 —B 2 O 3 —RO—R′ 2 O glass in which R is one or more members selected from Mg, Ca, Sr, and Ba; and R′ is one or more members selected from Li, Na, and K.
3. The semiconductor encapsulation material according to claim 2 , wherein the content of RO in the glass for metal encapsulation is 10% by mole or higher.
4. The semiconductor encapsulation material according to claim 2 , wherein the content of R′ 2 O in the glass for metal encapsulation is 1 to 20% by mole.
5. The semiconductor encapsulation material according to claim 2 , wherein the content of Li 2 O in the glass for metal encapsulation is 6% by mole or lower.
6. The semiconductor encapsulation material according to claim 2 , wherein the content of K 2 O in the glass for metal encapsulation is 2% by mole or higher.
7. The semiconductor encapsulation material according to claim 2 , wherein the content of K 2 O is highest among the contents of the R′ 2 O components in the glass for metal encapsulation.
8. The semiconductor encapsulation material according to claim 2 , wherein the content of Li 2 O is lowest among the contents of the R′ 2 O components in the glass for metal encapsulation.
9. The semiconductor encapsulation material according to claim 1 , wherein the content of B 2 O 3 in the glass for metal encapsulation is 5 to 18% by mole.
10. The semiconductor encapsulation material according to claim 1 , which is used for the encapsulation of a semiconductor element and a metallic lead wire.
11. A semiconductor encapsulation material according to claim 1 , wherein the glass for metal encapsulation comprises, in terms of % by mole, 40 to 75% of SiO 2 , 0 to 8% of Al 2 O 3 , 5 to 14% of B 2 O 3 , 10 to 45% of RO (wherein R is one or more members selected from Mg, Ca, Sr, and Ba), 0 to 20% of MgO, 0 to 20% of CaO, 0 to 35% of SrO, 1 to 35% of BaO, 1 to 20% of R′ 2 O (wherein R′ is one or more members selected from Li, Na, and K), 0 to 6% of Li 2 O, 0 to 12% of Na 2 O, and 2 to 15% of K 2 O.
12. The semiconductor encapsulation material according to claim 11 , wherein the content of K 2 O is highest among the contents of the R′ 2 O components in the glass for metal encapsulation.
13. The semiconductor encapsulation material according to claim 11 , wherein the content of Li 2 O is lowest among the contents of the R′ 2 O components in the glass for metal encapsulation.
14. The semiconductor encapsulation material according to claim 11 , which is used for the encapsulation of a semiconductor element and a metallic lead wire.
15. A method for semiconductor encapsulation which comprises encapsulating a semiconductor element and a metallic lead wire with the semiconductor encapsulation material according to claim 1 .
16. The method for semiconductor encapsulation according to claim 15 , wherein the lead wire is made of a base metal.
17. The method for semiconductor encapsulation according to claim 15 , wherein the lead wire is made of Dumet.
18. The method for semiconductor encapsulation according to claim 15 , wherein the semiconductor element is a thermistor chip.
19. The method for semiconductor encapsulation according to claim 15 , wherein the encapsulation is conducted at a temperature of 1,000° C. or lower.