| 摘要 |
Disclosed is a circuit substrate (l, 2) comprising an alumina plate (l) and an aluminum nitride plate (2) bonded to the alumina plate through metallized layers formed on the respective bonding surfaces of the alumina plate and the aluminum nitride plate and a buffering layer (9) provided between the metallized layers, the buffering layer being of a metallic material (a) which undergoes plastic deformation by recrystallization at a temperature of not higher than 500 DEG C, (b) which has a tensile strength of not higher than 35 kg.f/mm<2> at a temperature of 500 DEG C, and (c) which has an elongation of not less than l0 % at a temperature of 500 DEG C. The circuit substrate of this invention can provide a circuit substrate being excellent in heat disspating characteristic and free from the generation of crack on an operation. |
