PURPOSE: To improve reliability and to minimize increase of a part cost by forming a wiring pattern in both sides of a printed board and mounting a circuit part thereon and by ensuring a temperature to a circuit part of the both sides by heating both sides of the printed board simultaneously.
CONSTITUTION: The device is a printed wiring board wherein a wiring pattern is formed on both sides of first and second printed board 1, 2 and a circuit part is mounted thereon. A heat generating sheet 3 is interposed between both surfaces of first and second printed boards. The heat generating sheet is formed to a film form having the same configuration area as each printed board and is energized and generates heat when an atmospheric temperature in the neighborhood is not exceeding a usable lower limit temperature of a circuit part. Each printed board is heated simultaneously and uniformly all over.
ARAMAKI TATSUO
MITARAI TAKASHI
