Phase-Change Cooling in Fractal-Based Micro Channels

A heat flux of 1,000 watts/cm2 for the cooling of semiconductors in electronics will be achieved by exploiting three advanced technologies being developed at Oregon State University. Prior work indicates that this performance is well within the feasiblerange. The first technology involves micro channels which have been shown to improve cooling substantially. The primary historical disadvantages with micro channels have been excessive pumping power and poor temperature distribution. Both of theseproblems are solved by using fractal-like micro channels based on the circulation systems of mammals. By increasing cross sectional flow area at each of a series of branching stages, mass velocity and flow resistance are dramatically reduced. The secondtechnology involves active phase-change cooling with a conventional, non-toxic, non-explosive coolant. In the third technology, an advanced micro lamination process will be used for fabricating the micro channels, thus assuring manufacturability in volumeat reasonable cost. Using a 250 kW inverter as the targeted application, the team will optimize and evaluate the feasibility of a design exploiting these technologies. In the optional work, an experiment will be carried out to confirm the computationalmodel. The anticipated result for the Navy is a new thermal management system for all electronics, but particularly for the power semiconductors of high power electronics equipment to installed in future Navy ships. The civilian power electronics marketscombined are over $30 billion annually. All of these would benefit from the new thermal management approach since it not only reduces size dramatically, but also is conducive to volume, cost-competitive manufacturing.