SILICON NITRIDE COMPOSITE SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a Si3N4 composite substrate not causing cracks in the substrate even by mechanical impacts and thermal impacts an having excellent heat-releasing characteristics and heat cycle-resistant characteristics by using a Si3N4 substrate as a ceramic substrate. SOLUTION: This Si3N4 composite substrate is obtained by using a Si3N4 substrate having a heat conductivity of >=90 W/m.K and a three point bending strength of >=700 MPa and setting a metal layer tm joined to the main surface of one side of the Si3N4 substrate and the thickness tc of the Si3N4 substrate so as to satisfy a relation: 2 tm <=tc<=20 tm. When metal layers are joined to the main surfaces of both the sides of the Si3N4 substrate, the total thickness ttm of the metal layers on both the main surfaces satisfies a relation: ttm<=tc<=10 ttm.