Due to the continuous demand of higher lumen output,the power of high brightness LEDs has been raised substantially in the past 10 years.Higher power will indeed result in a higher junction temperature of an LED device.It has been well known that high junction temperature would exert a negative effect on the luminous efficiency and long term reliability of LEDs [1].As a result,thermal management became a crucial consideration in the design of an LED device.Despite of those LED devices that are packaged in chip on board (CoB) type,commonly the LED chips are packaged into individual components and then surface mounted to PCB for further applications.As commonly perceived,the PCB which connects the LED components to the heat sink is the major heat dissipating obstacle in an LED device.In order to reduce the thermal resistance from PCB,metal core printed circuit board (MCPCB) was introduced and has been widely accepted in HB-LED devices despite of the much greater costs than the common FR-4 PCB which is formed merely by woven glass fibers and epoxy.