To provide a method of taking measures against the electrostatic discharge damage to a bipolar type semiconductor and measures against breakdown due to heat generation of an MOS type semiconductor.
In a power source device 1, a control IC 3 manufactured by a bipolar process and a power supply element 4 manufactured by an MOS process are die-bonded on a lead frame 2 so that their chip ends are close to each other. Accordingly, the heat generated in the element 4 can be quickly transmitted to the IC 3, and the measures against breakdown due to heat can be taken. Also, the element 4 manufactured by the MOS process can easily realize low loss with a lateral structure. Consequently, the rear surfaces of chips of the element 4 and the IC 3 can obtain common GND potential, and both can be die-bonded by using one kind of die bonding paste represented by an Ag paste 5, thereby enabling taking measures against an electrostatic discharge damage which is a problem in a bipolar type semiconductor.
Shigeki Yamada
Junji Kodera