Measurement of power semiconductor heat exchanger temperature gradients

Miniature thermocouples and a data logger provided the ideal combination of suitable accuracy, low cost, small size, and electrical isolation to obtain thermal gradient data for evaluation of power semiconductor heat exchanger design. An uncertainty analysis was performed prior to the installation of the thermocouples to determine their suitability. This analysis also provided direction for a simple, straight forward data reduction procedure eliminating complicated error correction tables. Following laboratory testing of the thermocouples, the uncertainty analysis was repeated replacing estimated values with experimental ones. The results of this analysis and the trends in the heat exchanger data support the validity of the experiment. The final data reduction, not yet completed, will further enhance this confidence by providing cross check calculations of heat exchanger performance.