Allowable surge currents and failure mechanisms in semiconductor power devices in various modes of operation
Abstract
Because the allowable surge current in a semiconductor power device is determined by heating, it must be related to the allowable temperature and the latter must be calculated first. This is done for devices with pressure contacts on the basis of the corresponding system of two differential equations of transient heat conduction, one for the silicon crystal and one for the metal components. Calculations were made by this method for T-630 thyristors with pellet construction and pressure contacts. Such contacts are found to strongly inhibit heating under a half sine current surge. Conditional failure of thyristors such as spurious switching because of one or several parameters temporarily exceeding allowable limits as a result of a temperature rise is evaluated on this basis. Failure caused by the surge current following application of a reverse voltage is evaluated from the standpoint of the breakdown mechanism. Failure caused by a forward surge current in high injection devices such as p-i-n diodes is evaluated from the standpoint of the current filamentation mechanism and resulting perforation of the structure by melting.
- Publication:
-
USSR Rept Electron Elec Eng JPRS UEE
- Pub Date:
- September 1984
- Bibcode:
- 1984RpEEE.......63K
- Keywords:
-
- Failure;
- P-I-N Junctions;
- Surges;
- Temperature;
- Thyristors;
- Differential Equations;
- Electric Potential;
- Switching;
- Electronics and Electrical Engineering