| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor device in which a fine crack of an insulating substrate constituted of a ceramic or the like can be detected without impressing high voltage, and dielectic breakdown can be prevented. SOLUTION: At least one coil of a fine independent open loop copper foil pattern 2d is formed in the neighborhood of the outer peripheral part of the front side of an insulating substrate 2A in which a thick copper foil pattern 2b on which a power semiconductor element is mounted is formed on the front side of a ceramic board 2a, and a thick copper foil 2c is joined to the back side of the ceramic board 2a, and pads 2e are provided at the both edge parts of the open loop copper foil pattern 2d. This insulating substrate 2A is incorporated in a case, the pads 2e are connected with the outside terminal for a monitor provided in the case, and conduction between the outside terminals for the monitor is monitored. Thus, the presence or absence of a fine crack on the insulating substrate 2A can be detected. |
