| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power module that can prevent misrecognition of the end of service life, even if it is influenced by heat transfer from an adjacent power semiconductor element. <P>SOLUTION: Diodes 6a and 6b are provide at two positions at the center and periphery of the surface of an IGBT2 as a power semiconductor element, so as to detect their temperatures, and a temperature gradient (temperature difference) between temperatures at the center of the surface and in the periphery thereof is monitored by a temperature gradient monitoring means 7. An operation state detection means 8 detects the operating state of the IGBT2, namely ON-state or OFF-state, an element current detection means 9 detects large current operation of the IGBT2, and a life estimation means 10 estimates the service life, based on the monitoring result of the temperature gradient monitoring means 7 only when the operation state detection means 8 detects ON-state of the IGBT2 and the element current detection means 9 detects a large current operation of the IGBT2. Thus, when estimating service life, incorrect recognition arising from an influence of heat from other power semiconductor elements can be prevented. <P>COPYRIGHT: (C)2011,JPO&INPIT |
