Estimation of Power Semiconductor Junction Temperature from Package Body Temperatures

Abstract:
Measurement of power semiconductor operation junction temperature TJ is an essential part of power converters design, but it is not a straightforward task. This paper proposes a novel and easy to use approach by measuring temperatures on epoxy mold body of discrete power semiconductors to estimate TJ. A simplified thermal model is built to establish the relationship between different temperature points of interest. Finite element analysis (FEA) simulations are used to determine the correlation model parameters and then thermal measurements using infra-red (IR) camera are performed to confirm and validate the accuracy of the proposed method.