Modern methods and means for nondestructive testing of the quality of power semiconductor devices

Abstract

Modern methods and means for designing devices for nondestructive testing of parameters of power semiconductor devices are described. A new method for determining the junction–case thermal resistance from the transition function of a thermosensitive parameter is presented. The operating principle of a specialized digital system for controlling and displaying the vibration frequency and linear accelerations during testing of the absence of freely moving particles, short circuits, and breaks in the circuits of electrodes is presented. The function of digital filtering of a signal that is formed by the sensor–accelerometer board is considered. A new method for the formation of a single shock-current pulse is described that is based on the use of the principle of a discrete superposition of charges in the electric circuit of the secondary winding of a power pulse transformer. The principle of the formation of a test voltage pulse in a test-pulse generator of the software–hardware complex for the automatic assignment of grades, which is based on the implementation of the pulse-amplitude modulation of pulse parameters in a galvanically isolated power control loop, is presented.