초록 ▼

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

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.

대표청구항 ▼

1. An apparatus for minimizing thermal excursions, the apparatus comprising:a semiconductor device, operating at temperature equilibrium and in a pulse mode, the pulse mode comprising an on period and an off period, for which thermal excursions are to be minimized; and a PCM material, thermally coup

1. An apparatus for minimizing thermal excursions, the apparatus comprising:a semiconductor device, operating at temperature equilibrium and in a pulse mode, the pulse mode comprising an on period and an off period, for which thermal excursions are to be minimized; and a PCM material, thermally coupled to the semiconductor device, whereby the PCM material absorbs heat, from the semiconductor device, during the on period, by changing from a solid state to a liquid state and whereby the PCM material supplies heat, to the semiconductor device, during the off period by changing from a liquid state to a solid state. 2. An apparatus as in claim 1 wherein an amount of PCM thermally coupled to the semiconductor device is of sufficient quantity such that a portion of the PCM material, the portion being less than 100%, remains liquefied at all times when the semiconductor device is operating at temperature equilibrium.3. An apparatus as in claim 1 wherein the semiconductor device is a Gallium Arsenide semiconductor device.4. An apparatus as in claim 1 wherein the melting temperature of the PCM material is lower than a peak operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium and wherein the melting temperature of a PCM material is higher than the baseline operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium.5. An apparatus as in claim 1 wherein a melting temperature of the PCM material is lower than a baseline operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium.6. An apparatus as in claim 1 wherein the PCM material occupies an essentially constant volume when changing from the solid state to the liquid state.7. The apparatus of claim 5 wherein the melting temperature of the PCM material is lower than a peak operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium and wherein the melting temperature of the PCM material is higher than the baseline operating temperature of the semiconductor device when the semiconductor device is operating at temperature equilibrium.8. An apparatus as in claim 5 wherein an amount of PCM thermally coupled to the semiconductor device is of sufficient quantity such that a portion of the PCM material, wherein the portion is less than 100%, remains liquefied at all times when the semiconductor device is operating at temperature equilibrium.9. An apparatus as in claim 5 wherein the melting temperature of the PCM material is lower than a peak operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium, and wherein the melting temperature of the PCM material is higher than the baseline operating temperature of the semiconductor device when the semiconductor device is operating without PCM and is at temperature equilibrium.10. An apparatus as in claim 8 wherein the melting temperature of the PCM is chosen to be below the baseline temperature of the same semiconductor device operating without PCM and is at a temperature equilibrium condition, operating without any PCM coupling.11. The apparatus of claim 1 further comprising:a container for containing the semiconductor device, and the PCM, whereby the PCM is thermally coupled to the device. 12. An apparatus for minimizing thermal stress, the apparatus comprising:a substrate for supporting a semiconductor device, the substrate comprising a mounting side for attachment to a support surface and a device side for attaching the semiconductor device, the semiconductor device operated in a pulse mode; and mounted on the device side of the substrate; and a PCM material, thermally coupled to the semiconductor device, for absorbing heat from the semiconductor device by melting, during an on period of the pulse mode, and for supplying heat to the semiconductor device by solidifying, during an off period of the pulse mode. 13. An apparatus as in claim 12 wherein the PCM material is thermally coupled to the semiconductor device by placing an amount of PCM, sufficient to cover the semiconductor device, in such as manner as it covers the device.14. An apparatus as in claim 12 wherein the PCM material is thermally coupled to the semiconductor device by placing an amount of PCM, sufficient to cover the semiconductor device, in such as manner as it covers the semiconductor device and also covers the device side of the substrate.