Patent ID: 9538653
Date: 2017-01-03
CPC Classifications: C04B,H01B,H05K,Y10T

Claim:
1. An insulating substrate including through holes for conductors, said through holes being arranged in said insulating substrate: wherein a thickness of said insulating substrate is 25 to 100 μm; wherein a diameter of said through hole is 20 to 100 μm; wherein said insulating substrate comprises a main body part and exposed regions exposed to said through holes, respectively; wherein said insulating substrate comprises an alumina sintered body; wherein a relative density of said alumina sintered body is 99.5 percent or higher; wherein said alumina sintered body has a purity of 99.9 percent or higher; wherein said alumina sintered body has an average grain size of 3 to 6 μm in said main body part; wherein alumina grains of said alumina sintered body are plate-shaped in said exposed region; and wherein said plate-shaped alumina grain has an average length of 8 to 25 μm.