Thermal Analysis and PCB Design for GaN Power Transistor Pedro A. Rivera CURENT REU Final presentation 7/23/2015 University of Tennessee

Background Prototype power inverter - Smaller - Efficient GaN power transistor - High frequency switching - Low on-resistance - Operation in high temperatures Effects of high temperatures - Material wear down - Efficiency

Applications Electric/hybrid vehicles Solar energy Wind energy industry Domestic/commercial Military

Configuration Replace GaN transistor with resistor Experimental PCB design - Thermal vias - Bottom heat sink Taken from GaN systems app note

Objective Analyze heat dissipation of resistors and heat sink temperature Compare different PCB cooling designs Find the best cooling design

Calculate thermal resistance Method Experimental Simulation Theoretical GaN die Heat sink Obtain data from: - Resistor - Heat sink FEMM software - Materials - Measurements Calculate thermal resistance

Results Design #1 Experimental results match well simulation and theoretical results

Results Not much area under heat source Higher thermal resistance Design #2 Not much area under heat source Higher thermal resistance

Results Design #3 Improves design #2

Conclusion/Future work The use of thermal vias and heat sink on the bottom was the best design The farther away the heat sink from the heat source the worst the cooling will be Results can be used for comparison in future designs Create new designs to compare Use software with three dimensional viewing

Acknowledgements This work was supported primarily by the ERC Program of the National Science Foundation and DOE under NSF Award Number EEC-1041877. Other US government and industrial sponsors of CURENT research are also gratefully acknowledged.

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