A very high heat flux microchannel heat exchanger for cooling of semiconductor laser diode arrays

A low-cost, high heat flux heat exchanger for cooling of high power (of the order of 1000 W/cm²) semiconductor laser diode arrays has been designed and tested. The device uses a simple copper microchannel design to obtain very high fluid-to-wall heat transfer coefficients. Experimental results show that its overall thermal resistivity is less than 0.03°C/W, which is 2-3 times better than current state-of-the-art heat sinks. A different version of the heat sink has also been tested and has demonstrated the capability of dissipating 200-300 W from a conventionally (solder) bonded resistor of area of about 0.5 mm² while limiting its surface temperature rise 20-30°C. When operated at low pressures [0.48 MPa (70 psi)], this design also has a performance comparable to existing state-of-the art heat sinks so that it can be readily used as a replacement in current high power applications