US Patent 6976527 MEMS microcapillary pumped loop for chip-level temperature control

A microcapillary pumped loop (CPL) for chip level temperature control includes two mating substrates which define an evaporator, a condenser, and a reservoir for a liquid. A first substrate includes a vapor line which couples vapor from the evaporator to the condenser, and a liquid line which couples liquid from the condenser back to the evaporator. A wicking structure for the evaporator is formed by etching in the second substrate. The wicking structure couples the evaporator to the reservoir and to the liquid line. The condenser includes a plurality of grooves formed in the second substrate which couples liquid from the condenser to the liquid line.