Patent ID: 7145231

Claim:
An electronic apparatus comprising: a metal core substrate having a first surface and a second surface opposite to each other, the mail core substrate being provided with a core member constituted by a metal plate lying between the first surface and the second surface, a first wiring layer constituted by an insulating layer formed on said core member at a side of the first surface and a conductive layer, and a second wiring layer constituted by an insulating layer formed on said core member at a side of the second surface and a conductive layer; an electronic part having a main surface opposite the first surface of the metal core substrate and a terminal formed on the main surface to which the conductive layer of said first wiring layer on the first surface of the metal core substrate is connected; and a printed circuit board having a surface on which the metal core substrate is mounted so that an electrode formed on the surface of the printed circuit board is electrically connected the conductive layer of the second wiring layer exposed in the second surface of the metal core substrate, wherein: the core member has a window filled with an insulating material, the metal core substrate has a first via hole formed in the first surface of the metal core substrate and exposing the core member, a second via hole formed in the second surface of the metal core substrate and exposing the core member, and a through hole extended through the insulating material filled in the window of the core member and electrically connecting the conductive layer of the first wiring layer and the conductive layer of the second wiring layer formed on the second surface of the metal core substrate, a first heat radiating electrode formed of a high thermal conductivity material is provided in the first via hole to be in contact with the main surface of the electronic part and said core member exposed by the first via hole, a second heat radiating electrode formed of a high thermal conductivity material is provided in the second via hole to be in contact with the core member exposed by the second via hole, the conductive layer of the second wiring layer and the second heat radiating electrode are exposed in the second surface of the metal core substrate so that heat generated by the electronic part is conducted through the first heat radiating electrode, the core member, and the second heat radiating electrode in this order toward the second surface of the metal core substrate, the printed circuit board has a heat radiating electrode formed on the surface thereof, and the second heat radiating electrode exposed in the second surface of the metal core substrate is connected to the heat radiating electrode of the printed circuit board via a solder.