| 摘要 |
PROBLEM TO BE SOLVED: To alleviate produced stress and enhance durability and reliability by bonding on a metallized layer a metal plate of a specific substance which has a specific porosity and a specific gradient of porosity from the interior toward the surface or from one side to the other side. SOLUTION: A heat radiative wiring board is obtained by bonding an aluminum nitride board 2 directly to a radiator 1. A metal plate 4 which is composed of at least one element selected from among Ag, Cu, and Al, has a porosity of 1-30% and 1-20% gradient of porosity from its interior toward its surface or from one side to the other side is joined thereto with a metallized layer 3 in-between. Ni plating 5 is given thereto and a semiconductor chip 7 is bonded through solder 6. Thus the Young's modulus of the metal plate 4 is reduced to make the metal plate 4 easy to deform, and thereby stress due to difference in thermal expansion coefficient between metal and ceramics is reduced to ensure high reliability for heat radiative wiring boards. |
