This paper presents an investigation into the reliability of substrate bonding between metal layers and gallium arsenide vertical-injection light-emitting diodes (GaAs VLEDs). In this study, molybdenum (Mo) acts as a buffer layer between the GaAs VLED and the aluminum-based metal core printed circuit board (MCPCB). The thermal expansion coefficient (CTE) value of GaAs is approximately equal to that of the Mo layer under the substrate. This is beneficial for slowing the decay of the adhesive bond due to temperature cycling from − 40°C to 125°C for 50 cycles. The experimental results show that the use of the Mo buffer layer greatly improved the electrical and optical performance of the LED packages. The average leakage current was reduced from 33.63 mA to 2.37 mA at the reversed voltage of − 3 V and the increase in light output power was 130% at an injection current of 0.7 A. The results also show that a Mo buffer layer can reduce the risk of cracking on bonding wires after the thermal shock test (TST). These results are useful for improving the aging of GaAs VLEDs.

本文对金属层与砷化镓垂直注入发光二极管（GaAs VLED）之间的衬底键合可靠性进行了研究。在这项研究中，钼（Mo）用作GaAs VLED与铝基金属芯印刷电路板（MCPCB）之间的缓冲层。GaAs的热膨胀系数（CTE）值近似等于衬底下Mo层的热膨胀系数。这有利于减缓由于温度从-40°C到125°C的温度循环持续50个循环而导致的粘合剂衰减。实验结果表明，Mo缓冲层的使用大大提高了LED封装的电学和光学性能。平均泄漏电流从33.63 mA降低至2。反向电压为− 3 V时为37 mA，注入电流为0.7 A时光输出功率的增加为130％。结果还表明，Mo缓冲层可以降低热冲击后接合线上开裂的风险测试（TST）。这些结果对于改善GaAs VLED的老化是有用的。