| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide high bonding reliability to: a first solder layer still bonding even after passing through repeated thermal cycles, a circuit-side metal plate to a semiconductor element; and a second solder layer bonding a heat radiation-side metal plate to a heat radiation base plate. <P>SOLUTION: In this silicon nitride wiring substrate 10, the circuit-side metal plate 3 formed of copper or a copper alloy is bonded to one surface of a silicon nitride substrate 4; the heat radiation-side metal plate 5 formed of copper or a copper alloy is bonded to the other surface thereof; plated layers 6 are formed on surfaces of the circuit-side metal plate and the heat radiation-side metal plate; semiconductor elements 1 are bonded to the circuit-side metal plate with lead-free solder 2; and a heat radiation base plat 7 is bonded to the heat radiation-side metal plate with lead-free solder 8. In the silicon nitride wiring substrate, the difference among hardnesses of the circuit-side metal plate, that of the heat radiation-side metal plate and those of the plated layers is set to 330-550 in terms of Vickers hardness Hv; and the difference among Young's moduli of the circuit-side metal plate, that of the heat radiation-side metal plate and those of the plated layers is set to 0-70 GPa. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
