| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect degradation in a solder joint of a semiconductor power module efficiently and accurately. <P>SOLUTION: Extremely short-time short-circuit pulses 15a, 15b which do not exceed a short-circuit tolerance are input from a control circuit 10 to upper and lower arm elements (IGBT) 3a, 3b. A current value passing through, for example, the element 3a at that time is compared to a standard value 7a. It is decided that when the current value is a value other than the standard value 7a, degradation has been detected at the solder joint, thereby allowing degradation to be detected effectively and accurately. <P>COPYRIGHT: (C)2009,JPO&INPIT |
