| 摘要 |
PURPOSE:To enable a wiring board to be lessened in sheet resistance and improved in heat dissipating properties by a method wherein a wiring metal low in sheet resistance held by a resin film is provided around an element mounting stage, and the resin film on the rear side is bonded to the surface of a metal base with adhesive agent. CONSTITUTION:A metal base 5 whose thermal conductivity is 40X10<-6>kcal/ mm.S. deg.C) or above is partially coated with a ceramic thin film 9 so as to cover a semiconductor element mounting stage located on the surface of the metal base 5. A solderable metal thin film 12 is formed on the ceramic thin film 9, and a metal chip 11 specified in thickness so as to be as large in sheet resistance as 0.2mOMEGA/square or below is bonded onto the metal thin film 12 with a solder 10. On the other hand, A metal sheet of Al or Cu which is low in cost, small in resistivity, and so specified in thickness as to be 0.2mOMEGA/square or below in sheet resistance is held by a resin film 8 and etched into a wiring 2, and the wiring 2 is bonded to the metal base 5 with an adhesive agent 7 making the ceramic thin film 8. The metal chip 11 and the wiring 2 held by the resin film 8 are connected together with a bonding wire 4 or the like. |
