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.