Regenerator-Displacer for a Stirling Micro-Refrigerator for Cold Electronics

Sunpower proposes to design the regenerator-displacer component of a novel duplex free-piston Stirling micro-refrigerator for cold electronics in aerospace applications. The micro-refrigerator, to be located inside microelectronics packages, exploits the material properties, mechanical designs, tiny dimensions, and batch fabrication processes of silicon micromachining technology. If feasible, the micro-refrigerator will enable electronic devices bonded directly to its silicon cold plate, or fabricated within it, to operate at temperatures from 250K down to 60K or less, depending upon the application-specific design. Thermodynamic simulations predict a nominal 1 W of heat lifting capacity from 225K by micro-refrigerators <lcm3 in volume with an electrical input power of <10 W. For MxN greater heat loads, MxN micro-refrigerators could be fabricated as a mechanically integrated MxN cm2 array. The duplex micro-refrigerator is comprised of only four structural components: a regenerator-displacer, a piston, a heat exchanger, and a circuit substrate. Later these components will be integrated into a functioning micro-refrigerator. In Phase I, interrelated dynamic, thermo-dynamic, stress, and entropy analyses of the proposed regenerator-displacer component will be performed, and a silicon micromachining process will be designed for fabricating and testing the regenerator-displacer component in Phase II.