Microfluidic two-phase cooling of a high power microprocessor part A: Design and fabrication

The effective use of embedded radial expanding microchannels with micro-pin fields for two phase cooling of a microprocessor die has been demonstrated. In this first part of a two part paper, the integration of this approach into a functional high performance server is presented. Modeling was conducted to design radial micro-channels, micro-pin fields, and orifices to properly distribute flow according to the anticipated maximum work load distribution of power across the processor chip. This design incorporates modeling of two-phase pressure drop under power, allowing for a tight distribution of exit vapor quality across the radial channels. Integrating this technology into a functioning server requires a packaging design and assembly approach compatible with an originally lidded fully functional organic single chip processor module. Processes for de-lidding, channel etching, and packaging for desired coolant flow and thermal behavior through the chip-embedded channels were developed. The resulting processor modules were re-installed in a commercial server and the fluidic performance was measured. In the second part, the functional performance experiments and results are detailed.