Convective heat transfer from a die-stacked electronic package

Convective heat transfer from a vertically stacked [3-D] electronic package (die-stacking) mounted in between two circuit boards is numerically investigated. Heat transfer characteristics of single chip packages and multiple-die packages for both two and four die stack are presented and compared. The package Reynolds number, based on the package height and upstream velocity, ranges from 150 to about 1000. The channel aspect ratios is approximately H/B= 9 with flow bypass > 5B, wherein B is package height and W is the height of the channel. The effect of board conduction on the heat transfer performance from the package is also quantified. A valuable finding is that, in the present set of configurations, the heat transfer for a multi-die stack, such as a two-die stack or a four-die stack, can be reasonably predicted using the heat transfer information from a single chip package by employing a simple scalar factor. Finally, the effects of non-uniform heating on the die temperatures of the different packages in a stack are examined.