SINTERED CERAMIC AND SUBSTRATE COMPRISING SAME FOR SEMICONDUCTOR DEVICE

摘要

A ceramic sintered member is used as an insulating substrate for mounting of an electronic part and bonded to a copper plate or aluminum plate on at least part of a front face or backside face of the insulating substrate. A powder material to form the ceramic sintered member includes alumina as a main ingredient and further includes as subsidiary ingredients partially stabilized zirconia and magnesia. Content of the partially stabilized zirconia is 1 to 30 percent by weight relative to the entire powder material. Content of the magnesia relative to the entire powder material is within a range 0.05 to 0.50 percent by weight. Mole fraction of yttria in the partially stabilized zirconia being is a range of 0.015 to 0.035. 80 to 100 percent of the zirconia crystals included in the ceramic sintered member is in the tetragonal crystal phase.