Electronic device for use in vehicle, has heat reception passage formed in wiring pattern of board with potential as other wiring pattern and lying opposite to heat radiation passage over isolation portion of boards in transverse manner

摘要

The device has a transistor (31), an aluminum electrolytic capacitor (32) and a chip resistor (33) mounted on a board surface (11a) of a printed circuit board (10). A heat radiation passage (41) of the board is formed in a wiring pattern (12). The transistor is connected with the passage extended from the pattern in inner side of the boards. A heat reception passage (42) is formed in another wiring pattern (17) with potential as the former pattern, and lies opposite to the radiation passage over an isolation portion of the boards in transverse manner. The printed circuit board is a multi-layered printed circuit board.