Patent ID: 6013935
Filing Date: 2000-01-11
Classification: H01L

Abstract:
A solid-state switch driven by thermovoltaic generator, comprising:a silicon substrate;a MOSFET with gate receiving a signal such that output load can be controlled;a thermal pad disposed on a local region of said silicon substrate by micromachining technology for thermal isolation;a thin-film heating resistor disposed on said thermal pad, which is the input end of the switch; anda thermopile consisting of a plurality of p-n junction semiconductor thin-film thermocouples in series connection, the hot junctions of said thermocouples being disposed on said thermal pad and contiguous to said thin-film heating resistor with sufficient dielectric strength between them, the cold junctions of said thermocouples, with temperature being the same as that of said substrate, being disposed on the substrate region far from said thermal pad, the output end of said thermopile being used as the input end of said MOSFET;as an input voltage being applied to said thin-film heating resistor, Joule's heat being generated at said heating resistor, a proper temperature difference thus appearing between the hot junctions and the cold junctions of said thermopile due to non-uniform heat distribution, which induces a thermoelectric potential at the output of said thermopile for turning on said MOSFET; as said input voltage being removed, the temperatures of the hot and cold junctions becoming the same owing to thermal equilibrium, the thermoelectric potential appearing at said output end of said thermopile becoming zero, which turning off said MOSFET.