循环电载荷下大功率LED金引线疲劳断裂寿命预测

Fatigue fracture lifetime prediction for gold bonding wires of high-power LED under cyclically electrical loading

随着大功率发光二极管(LED)在照明领域的普及与广泛应用,可靠性逐渐成为研究的重点。大功率LED封装器件中金引线疲劳断裂失效一直是制约其可靠性的重要因素。通过针对大功率LED封装器件中的金引线力学仿真与功率循环试验相结合的方法,首先确定循环电载荷条件下该型LED的主要失效原因为金引线疲劳断裂,其次提出基于电流加速模型的加速因子提取方法和基于应变幅值的Coffin-Manson解析寿命预测方法,最终完成对LED金引线疲劳断裂寿命的预测和试验验证。研究结果表明:所提方法具有较高的寿命预测精度,可以满足大功率LED封装器件可靠性快速、准确评估的要求。

With the popularity and widespread application of high-power light-emitting diode(LED) in lighting industry,its reliability has gradually become one of research focuses. The failure of gold bonding wires in the traditional LED package has been a critical bottleneck that restricts its reliability. In this paper,the failure mechanism of LED under cyclically electrical loading is firstly identified through both gold bonding wire mechanical simulation and power cycling test experiment,which is the fatigue fracture of gold bonding wire.Then,two lifetime prediction methods,the acceleration factor extraction method based on current acceleration model and the strain-based Coffin-Manson analytical method,are established and verified with experimental results. The results show that the lifetime prediction accuracy of the proposed methods is high and they can achieve a fast and accurate reliability assessment for high-power LEDs with wire-bonding packaging technology.