Patent ID: 8263870

Claim:
A heat radiating wiring board having two generally planar parallel surfaces, comprising: a plurality of circuit patterns each comprising a metal wiring plate; a resin plate having insulating properties into which filler is mixed; and a heat sink, wherein: the circuit patterns are attached to one side surface of the resin plate, a top surface of the circuit pattern is exposed at the one side surface of the resin plate, and substantially flush with a top surface of the resin plate, the heat sink is attached to the other side surface of the resin plate, each circuit pattern of the circuit patterns is a single metal wiring plate, which has a thick portion and a thin portion thinner than the thick portion in a thickness direction of the resin plate, an inclined side surface connecting the thin portion and the thick portion in the circuit pattern, the inclined side surface having an inclination angle of more than zero degrees with respect to a plane perpendicular to the two generally planar surfaces of the wiring board, and a thickness of the resin plate between the thick portion and the heat sink is smaller than a thickness of the resin plate between the thin portion and the heat sink.