Temperature sensing arrangements for power electronic devices
View Patent ↗A cooling system is provided for controlling temperature in a power electronic device. The power electronic device includes a semiconductor having a major surface. The cooling system includes a temperature sensor coupled to the major surface of the semiconductor; and a control circuit coupled the temperature sensor. The control circuit is configured to reduce current to the inverter circuit when the temperature exceeds a predetermined temperature.
1. A substrate subassembly comprising:
a ceramic wafer having first and second opposed metallized major faces;
a first metal tab on the first metallized face that extends away from the ceramic wafer for electrical connection to a first terminal member;
a semiconductor switching device electrically conductively bonded to the first metallized face of the ceramic wafer, wherein the semiconductor switching device includes electrodes on a first surface;
a first ceramic layer bonded to a portion of the first metallized face of the ceramic wafer adjacent the semiconductor switching device, the first ceramic layer having a metallized first surface;
a second metal tab on the metallized first surface of the first ceramic layer that extends away from the ceramic wafer for electrical connection to a second terminal member;
a first metal layer conductively bonded to the electrodes on the first surface of the semiconductor switching device and also to the metallized first surface of the first ceramic layer;
a second ceramic layer bonded to the first metal layer, the second ceramic layer being disposed over the semiconductor switching device;
a second metal layer bonded to the second ceramic layer, wherein the first metal layer, the second ceramic layer, and the second metal layer form an interconnect that approximately matches a thermal coefficient of expansion of the semiconductor switching device; and
a temperature sensor coupled to the semiconductor switching device, the temperature sensor configured to measure the temperature of the semiconductor device.
2. The substrate subassembly of claim 1 , wherein the semiconductor switching device is an IGBT.
3. The substrate subassembly of claim 1 , wherein the temperature sensor is a thermistor.
4. The substrate subassembly of claim 1 , wherein the temperature sensor is bonded to the second metal layer.
5. The substrate subassembly of claim 1 , wherein the temperature sensor is bonded to the second ceramic layer.
6. The substrate subassembly of claim 1 , further comprising a diode disposed adjacent to the semiconductor switching device, and an additional temperature sensor coupled to the diode.
7. The substrate subassembly of claim 1 , further comprising a power control circuit electrically connected to the temperature sensor and configured to control DC current to the semiconductor switching device, the power control circuit configured to reduce current to the semiconductor switching device when the temperature of the semiconductor switching device exceeds a predetermined temperature.
8. The substrate subassembly of claim 7 , wherein the predetermined temperature is about 150° C.
9. The substrate subassembly of claim 7 , wherein the power control circuit is configured to reduce the current to the semiconductor switching device to substantially zero when the temperature exceeds the predetermined temperature.
10. The substrate subassembly of claim 7 , further comprising first and second bases mounting the temperature sensor onto the semiconductor switching device and spaced at a distance from one another, the temperature sensor bridging the two bases.
11. The substrate subassembly of claim 7 , further comprising a diode disposed adjacent to the semiconductor switching device, and the predetermined temperature of the semiconductor switching device being a first predetermined temperature, and
wherein the system further comprises an additional temperature sensor mounted on the diode and connected to the control circuit for reducing current to the semiconductor switching device when the diode exceeds a second predetermined temperature.