| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a power module in which insulation resistance, e.g., partial discharge or creeping dielectric breakdown voltage, is enhanced by suppressing defect formation on the boundary surface of an insulating substrate and a silicone gel of the power module.SOLUTION: In the power module including an insulating substrate, a conductor provided on the insulating substrate, a semiconductor chip installed on the conductor, and a silicone gel for sealing the insulator, the conductor and the semiconductor chip, surface of the insulating substrate is subjected to plasma processing in the state of reduced pressure, silicone gel is cast in the atmosphere subjected to plasma processing without exposing to the atmosphere, and then purged with gas, and the silicone gel is subjected to heat curing treatment in the atmosphere of gas thus purged. Preferably, the purge gas is nitrogen, and/or carbon dioxide and/or sulfur hexafluoride. Preferably, plasma processing, casting of silicone gel, gas purge, and heat curing treatment are performed in situ. |
