Thermal transient testing is a tool for examining structural
details of a heat conducting path composed of heat conduction
and heat convection sections. Using the change of inherent heat
in electronics, temperature transients provide a characterisation
technique where using x-ray or acoustic microscopy would be
troublesome and time-consuming.
A complete toolkit for the accurate dynamic characterisation
of subassemblies and cooling mounts is described in the
paper. After giving the theoretical background, it is shown that
the methodology can directly generate a valid and detailed
structural equivalent from a single transient measurement.
The descriptive thermal functions such as time constants
and structure functions are demonstrated in practical examples,
the capability of the structure functions for validating cooling
concepts and detecting assembly problems is shown.
Recognising the fact that systems with multiple energy
transport such as electric energy converted to heat and light
exhibit special features; the concept of structure functions has
been modified for applications in solid state lighting.
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .