随着功率型LED(HP-LED)对散热的要求越来越高, 传统导电银胶越来越难以满足LED的高散热要求。虽然共晶互连工艺是微电子领域中的一种有效的散热互连方法, 但是由于LED的特殊性, 该工艺在LED互连封装中的性能改善研究还比较少。本文对金锡共晶互连、锡膏互连和银胶互连的3种LED器件分别进行了光学、热学以及剪切力等方面的测试分析研究, 结果表明: 底部与顶部同时加热的金锡共晶工艺互连的LED器件可以有效地改善仅底部加热共晶互连层中的空洞缺陷, 在1 000 mA电流条件下, 相对于锡膏、银胶互连的LED器件具有较低的热阻、较稳定的峰值波长偏移、较强的互连层剪切力等性能。金锡共晶互连工艺是一种可以有效改善大功率LED散热及互连强度的方法。

Thermal management is the challenge of HP-LED packaging. Silver paste is the interconnect material for common LED, but it can hardly dissipate the heat effectively for HP-LED now, especially for multichip HP-LED. Gold-tin (80Au20Sn) eutectic interconnect is a method can improve the heat dissipation, but the eutectic process is complicated as the HP-LED top surface is an emitting surface. In order to investigate the thermal performance improvements of HP-LED interconnected by Au80Sn20, HP-LEDs interconnected by Au80Sn20, solder paste and silver paste are prepared. Firstly, the effects of heating method between bottom and top heating together with bottom heating only are investigated. Secondly, the thermal resistance comparison, the wavelength shift between 50 mA and 1 000 mA, the shear force test are investigated respectively. The results show that the thermal resistance of HP-LED interconnected by Au80Sn20 is obviously lower than that of the HP-LED interconnected by solder paste and silver paste. The wavelengh shift of HP-LED interconnected by Au80Sn20 is the smallest; the shear force results show the HP-LEDs interconnected by Au80Sn20 is the best. Based on the above tested results, the eutectic interconnect process is an effective method to improve the HP-LED heat dissipation.