ATE32808T1 - SURGE-ABSORBING SEMICONDUCTOR ARRANGEMENT. - Google Patents

Abstract

Transient Absorption Semiconductor Device A transient absorption semiconductor device comprises a thin planar semiconductor body of one conductivity type having regions of opposite conductivity type diffused into opposite surfaces thereof so as to define relatively closely spaced rectifying junctions which interact with one another when the device is subjected to an overvoltage causing the reverse biased one of the junctions to breakdown from a low to a relatively high conductivity state. With an increase in the magnitude of the current flowing in the device, the potential difference developed across the device decreases from the breakdown voltage but does not decrease below a set non-zero voltage. It is believed that majority charge carriers from the forward biased junction are swept into the reverse biased junction in increasing numbers with increasing surge current which modifies the characteristics of the broken down junction and produces the decreasing voltage characteristic. Because the voltage drop across the devie decreases after breakdown, the surge current handling capability of the device is increased and transient absorption devices can correspondingly be manufactured in smaller sizes than heretofore and with less associated heat dissipating encapsulation. Also disclosed is a dual device with greater power handling capabilities.