Laminated wiring board and its mounting structure

摘要

A laminated wiring board comprising: a first wiring board forming wiring layers on the upper surface and on the lower surface of a first ceramic insulated substrate; and a second wiring board forming wiring layers on the upper surface and on the lower surface of a second ceramic insulated substrate; the wiring layer on the lower surface of the first wiring board and the wiring layer on the upper surface of the second wiring board being connected together through connecting electrodes; wherein a coefficient alpha1 of thermal expansion of the first ceramic insulated substrate at 0 to 150° C. and a coefficient alpha2 of thermal expansion of the second ceramic insulated substrate at 0 to 150° C. are satisfying the following conditions: alpha1<ALPHA2 alpha2-alpha1<=9X10<-6>/° C. The laminated wiring board offers a high degree of mounting reliability even when it is interposed between the electric device such as a silicon semiconductor device having a small coefficient of thermal expansion and an external circuit board such as a printed board having a large coefficient of thermal expansion.