Abstract: A method of detecting a fault of a semiconductor device including a power device mounted on a metal base and a drive circuit for driving the power device, the method detecting a fault of the semiconductor device beforehand based on an increase in thermal resistance between the metal base and the power device. A state of the power device is measured immediately before and after the power device is driven by the drive circuit. A temperature difference of the power device before and after driving is calculated according to the result of measurement. An increase in thermal resistance between the metal base and the power device is detected based on the temperature difference and an amount of electricity inputted to the power device in the driving period, and a fault of the semiconductor device is detected beforehand according to the increase.

Abstract: An obtained margin is smaller than a margin to be kept for a fault period predicted by life prediction based on a power cycle test, extending a maintenance cycle for replacement and so on. A method of detecting a fault of a semiconductor device including a power device mounted on a metal base and a drive circuit for driving the power device, the method detecting a fault of the semiconductor device beforehand based on an increase in thermal resistance between the metal base and the power device. A state of the power device is measured immediately before and after the power device is driven by the drive circuit. A temperature difference of the power device before and after driving is calculated according to the result of measurement.

Abstract: The size of a light emitting device is reduced. The light emitting device for flash photography includes: a luminescent xenon tube; IGBT for the discharge switch of the xenon tube; a capacitor for discharging the xenon tube; and MOSFET for the charge switch of the capacitor. A semiconductor device used in this light emitting device is obtained by sealing the following in a package: a semiconductor chip in which the IGBT is formed; a semiconductor chip in which the MOSFET is formed; a semiconductor chip in which a drive circuit of the IGBT and a control circuit of the MOSFET are formed; and multiple leads coupled thereto.