A silicon-aluminum micro heat sink for light emitting diode (LED) chips

High-power light emitting diode (LED) technology has developed rapidly in recent years because of the urgent need to reduce carbon emission. With the increasing illumination intensity of LEDs, thermal management became a critical issue in LED device design. Combining a heat pipe with a heat sink is a method in thermal management for high power LEDs. In this paper, an LED substrate integrated with the heat management device is proposed. Three LED chips were bonded on one surface of the silicon wafer with the dimension of 22 mm (length) × 8 mm (width)×1 mm (thickness) using silver glue. Micro grooves were fabricated on the other side of the silicon wafer. An aluminum heat sink was bonded to the wafer on the groove side, thus, the silicon wafer and the heat sink composed the integrated LED substrate. There was only one thermal interface, which is chip/silicon interface, from LED chips to ambient. Thermal testing experiments were carried out to study the module´s heat dissipation capability. Hopefully, with less thermal interface, this module can keep at a reasonable working temperature with such an impacted packaging.