PURPOSE: To enable a wiring board to be improved in sheet resistance and heat dissipating properties by a method wherein a thin metal film is directly formed on a ceramic thin film, a wiring metal low in sheet resistance is provided onto an element mounting stage, and a resin film on the rear side is bonded to the ceramic thin film formed on a metal base.
CONSTITUTION: A ceramic thin film 9 is partially formed on a metal base 5 40×10-6kcal/mm.s.°C or above in thermal conductivity, and a thin metal film 10 of Au, Al, Cu, or the like is formed on the ceramic thin film 9 provided onto the semiconductor element mounting stage. A metal sheet of Al or Cu which is low in cost, small in resistivity, and so specified in thickness as to be 0.2mΩ/square or below in sheet resistance is held by a resin film 8 and etched into a wiring 2, and the resin film 8 is bonded to a coating layer through an adhesive agent. As mentioned above, the metal thin film 10 formed on a ceramic thin film and the wiring 2 held by the resin film 8 are connected together through a bonding wire 4 or the like, whereby a required wiring board can be obtained.
TAKIGAWA TAKATOSHI
YAMANAKA SEISAKU
