�Omega� fin design for enhanced cooling capability on IGBTs

Abstract

Vehicle electrification is a rapidly growing and developing technology. As with any new technology there are hurdles that must be overcome as development marches forward. Overcoming these obstacles will require new and innovative solutions. One area of electrification that is quickly developing is the ability to convert voltage from AC to DC and from DC to AC. This is important since the battery pack outputs a DC voltage which must be converted to AC to drive the electric motor. The reverse is true when braking, the AC voltage generated by the electric motor is converted to DC in order to charge the battery. The conversion of voltage back and forth is controlled through the use of an inverter. The inverter uses Insulated-Gate Bipolar Transistors or IGBTs which generate heat while in operation. As the IGBTs heat up their efficiency goes down. In order to maintain a high level of efficiency the circuity can be directly cooled through the use of a heat sink. A unique �Omega� fin design has been developed for use in IGBT heat sinks. This unique �Omega� fin design allows for increased heat transfer while maintaining a sufficient coolant flow passageway so that particles do not get trapped. The added heat transfer provides for an increase in efficiency of the IGBT. This report reviews the heat transfer performance of a traditional fin and how that compares with the �Omega� fin design. Results are provided in both analytical and empirical form, proving the �Omega� fin has higher performance than traditional fin design in the same packaging space. The contents of this publication are also the subject of a patent application that is pending before the United States Patent and Trademark Office as of the date of this publication.