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White Paper

Thermal characterization of complex electronics: understanding structure functions

Learn how semiconductor thermal transient testing and structure function analysis (thermal resistance vs thermal capacitance profiles) aid design of reliable electronics

This whitepaper describes how thermal transient measurement for semiconductor component thermal characterization is used in electronics development to help reduce risks of product thermal failure and recalls. It focuses on the value of heat flow path analysis using Structure Functions to determine component and package thermal metrics, for failure diagnosis, and to improve thermal simulation model accuracy during electronics product development.

Structure Functions are a thermal resistance versus thermal capacitance profile of the heat flow path from junction to ambient and derive from precise transient junction temperature measurement. They provide detailed thermal information on each layer in a package. Engineers can identify physical characteristics of layers including die-attach, base, thermal interface material, package case, and even to characterize cooling device performance such as heatsinks, fans, and cold plates.

The whitepaper includes three examples of using Structure Functions in electronics and semiconductor applications: LED lighting to characterize interface thermal resistances & identify defects, Thermal Interface Material (TIM) bulk thermal conductivity measurement, and for calibration of a component thermal model.

Topics include:

  • Electrical test methods (incl. JEDEC test standards), junction temperature (Tj) and thermal impedance measurement 
  • Using Structure Functions to determine thermal metrics incl. thermal resistance (Rth) and thermal model calibration
  • Guidance on cumulative and differential Structure Functions