A study is reported of heat transfer and air flow in an electronic module consisting of an array of narrowly spaced vertical circuit boards with highly-protruding components contained in a naturally vented chassis. A two-dimensional simulation model is developed that accounts for heat transfer by conduction, convection, and radiation, and sensitivity studies are performed. Experiments are conducted using a specially constructed test module. Comparisons with the experiments reveal the need to calibrate the model by selecting an effective component height that represents the drag properties of the actual three-dimensional component geometry. The need to account in the model for heat losses in the depth direction is also discussed. The importance of accurate thermophysical properties and of multi-dimensional radiation is shown. Good agreement with measured velocities and local board temperatures is obtained over a wide range of power levels, and it is concluded that the calibrated model is capable of representing the thermal behavior of the present module.

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