| abstract |
A multi-layered substrate capable of lowering transient and steady heat resistances. A metal serving as a heat conductor having good heat conducting property is fitted in the uppermost insulating layer, and a power element is disposed on the fitted metal. The heat generated by the power element is conducted to the metal in the uppermost insulating layer and is radiated. The metal can be composed of a mixture of molybdenum particles or tungsten particle having a high melting point and aluminum particles. |