Preparation of PCB Substrate Embedded with Ceramic Circuit Board and its Application for LED Packaging

In this work, printed circuit board (PCB) substrate embedded with ceramic circuit board (referred to as "embedded substrate") was fabricated by fixing a direct plated copper ceramic (DPC) substrate to the pre-opening area of PCB substrate with adhesive. Due to the high thermal conductivity of ceramic material, the local heat dissipation of embedded substrate can be strengthened. Compared with ordinary PCB substrate, the surface temperature of LED packaged by the embedded substrate is lower. When the current increases from 200 to 400 mA, the surface temperature rise of embedded substrate is about 42.1°C lower than that of ordinary PCB substrate. Importantly, the embedded substrate can reduce the negative impact of temperature rise on the LED chip and improve the optical performance of device. As the current increases from 200 to 700 mA, the optical power of LED packaged by the embedded substrate increases from 303.1 to 712.6 mW. And the LED can be lighted at 700 mA while ordinary PCB substrate has lost its ability to work. The results show that the embedded substrate can effectively improve the heat dissipation performance of high-power LED with the advantages of high performance and low cost, which can meet the requirements of power device packaging applications.