| 摘要 |
<p>PURPOSE:To enable components to dissipate heat well toward a metal base board and to provide a first circuit pattern even to a component mounting part so as to improve a circuit board in wiring density by a method wherein a part of an upper circuit board on a first circuit pattern is cut out to partially expose the first circuit pattern, and the exposed part is made to serve as a component mounting part or a connection part with a second circuit pattern. CONSTITUTION:A part of an upper circuit board 4 on a first circuit pattern 3 is cut out through a punching work or the like, so that the first circuit pattern 3 is partially exposed at the part where the circuit board 4 is cut out. The exposed part 3a concerned is made to serve as the mounting part of a heat releasing component 9 or a connection part with a second circuit pattern 6A. The component 9 is fixed onto the exposed part 3a of the first circuit pattern with a eutectic solder 11, and a lead 12 of the component 9 is connected to the second circuit pattern 6A. Another exposed part 3a of the first circuit pattern is connected to the second circuit pattern 6A with a bonding wire 10. By this setup, as a component can be mounted on a first circuit pattern 3 which is excellent in thermal conductivity and heat dissipating property to a metal base, the component can be kept well in heat dissipating property.</p> |
