Abstract

The thermal resistance of requisite thin dielectric layers between high power dissipating devices and thermal ground, i.e., the base of a heat sink, is substantial. Thus power devices are frequently mounted on a heat spreader attached to the dielectric layer to reduce this thermal resistance. This paper provides analytically-derived formulae and accompanying dimensionless plots for the thermal resistance between the power device/heat spreader interface and thermal ground as a function of the relevant dimensionless geometric and thermal parameters for the axisymmetric and one-dimensional Cartesian geometries. These formulae/plots can be used to properly size the thickness and footprint of heat spreaders above dielectric layers. The utility of the results is demonstrated by an example.

This content is only available via PDF.
You do not currently have access to this content.