摘要
将功率循环方法应用于大功率LED焊料层的可靠性研究,对比分析了在650mA,675mA和700mA电流条件下大功率LED焊料层的热阻退化情况。实验结果表明,循环达到一定次数,大功率LED热阻才开始退化,并呈线性增加,从而引起光通量下降;另外,失效循环次数与电流值之间呈线性关系,并外推出正常工作条件下焊料层寿命为90 968次。对样品进行了超声波检测(C-SAM),发现老化后LED焊料层有空洞形成,这说明空洞是引起热阻升高的主要原因。
An improved method of power cycling was presented to study the reliability of solder joints in high- power LED whose heat extraction capability would affect the optical efficiency and reliability of LED. In the 650 mA, 675 mA and 700 mA current condition, comparison and analysis for thermal resistance degradation on solder joints of LED had been carried out. The experimental results demonstrated that the thermal resistance of high power LED increased significantly with the number of cycles reaching a certain degree, and a decline in luminous flux was caused. The relationship between current and failure number of cycles was linear. According to this relationship, the thermal fatigue life of solder joint was extrapolated to 90 968 times under normal operating condition. Finally, some voids were found in the solder joints by scanning acoustic microscope（C-SAM）, and the reason of the increased thermal resistance was clearly due to the voids.
出处
《微电子学》
CAS
CSCD
北大核心
2016年第3期429-432,共4页
Microelectronics
基金
广东省教育部产学研结合项目(2011B090400463)
关键词
功率循环
大功率LED
焊料层
热阻
Power cycling
High power LED
Solder joint
Thermal resistance
