Cooling system for pulsed power electronics

Abstract

The invention discloses an apparatus for reducing peak temperatures and thermal excursions, of semiconductor devices, particularly in pulsed power applications. The apparatus comprises thermally coupling Phase Change Material (PCM) to the dissipating semiconductor device. PCM absorbs heat and stays at a constant temperature during its phase change from solid to liquid. The PCM melting point is chosen so that it is just below the temperature the device would otherwise achieve. When the device approaches the maximum temperature, the PCM melts, drawing heat from the device and lowering the device's peak temperature. As the device stops dissipating, after its pulse period, the PCM material solidifies releasing the heat it absorbed. The apparatus lowers the peak temperature by absorbing heat when the device is dissipating. The apparatus also keeps the semiconductor device from cooling off as much as it would cool without the apparatus, as the PCM material releases heat during the part of the cycle when it is re-solidifying, i.e. when the pulse power is off. By lowering the peak temperature the device achieves, and increasing the temperature of the device when it is in the off portion of its pulsed power cycle the temperature excursions of the device during operation are reduced. By reducing the temperature swings, that the device sees during operation, the thermal stress is reduced and the reliability of the device is improved.