POWER SEMICONDUCTOR MODULE

PROBLEM TO BE SOLVED: To reduce stresses caused in solder function section of electrodes due to the thermal expansion of silicone gel by providing inside a cover plate a protrusion retaining an upper control board downward. SOLUTION: This power semiconductor module comprises a power circuit board 16 housed in a lower space of a case 23, a control circuit board 13 housed in an upper space, inner wiring lead pins 15 wired between boards, a sealing resin 12 filled in the case 23, and a cover plate 10 disposed on an upper control board 13. Inside the cover plate 10 a protrusion 11 is provided for pressing downward a control circuit board 13 from above side, thereby preventing the control circuit board from shifting up. The cover 13 is made of the same material as the case 23, a silicone gel pouring hole 24 is sufficiently wide to provide escape for the silicone gel 12 being thermally expanded. This fully suppresses the control circuit printed board 13 from shifting up and relaxes a stress caused in solder function.