| 摘要 |
PROBLEM TO BE SOLVED: To improve an insulating characteristic between a metal board and a wiring, improve heat resistance between the metal board and the wiring and heat radiation properties at the rear face, and improve a temperature compensation circuit. SOLUTION: A first insulating resin film 14 is formed thick, breakdown voltage characteristic is improved, by mixing a filler the heat of a heater element is transmitted satisfactorily to a hybrid integrated circuit board 11. In the rear face of the hybrid integrated circuit board 11, scarring-proof property is improved by a second insulating resin film 13. In a push/pull circuit for driving a loudspeaker SP, current-suppressing resistors can be omitted by making a thermal resistance small. |
