Patent ID: 9269742
Filing Date: 2016-02-23
CPC Classification: C03C,H01L

Claim Text:
1. A cover glass for semiconductor package, comprising, in terms of percentage by mass, from 58 to 69% of SiO 2 , from 4 to 20% of Al 2 O 3 , from 0 to 5% of B 2 O 3 , from 0.1 to 20% of Na 2 O, from 0.02 to 7% of K 2 O, from 0 to 3% of Li 2 O, from 0 to 3% BaO, from 0 to 0.5% of ZrO 2 , and from 0 to 20% of alkaline earth metal oxides, wherein the cover glass has a ratio by mass of (Na 2 O+K 2 O)/Na 2 O of from 1.24 to 10, an average thermal expansion coefficient of from 90 to 180×10 −7 /° C. in the temperature range of from 30 to 380° C., a Young's modulus of 68 GPa or more, an emission amount of alpha-ray from the glass of 0.05 c/cm 2 ·hr or less; and comprises a total amount of alkali metal oxides and alkaline earth metal oxides of from 21 to 35% by mass.