中文摘要：

介绍了发光二极管（LED）封装工艺中常见焊接缺陷与可能存在的危害。对污染物造成的焊接缺陷作了具体研究，理论分析了因缺陷引入的接触电阻和隧道电阻，测量了正常情况和缺陷焊接时LED的光谱和光生电流，并提出了存在缺陷焊接的LED的等效电路，对实验结果进行了分析。结果表明：LED发生焊接缺陷时的发光强度、光生电流明显比正常情况小，可以通过测试LED芯片的发光强度或光生电流达到检测LED焊接缺陷的目的。该研究对提高LED封装的可靠性和提出检测LED焊接缺陷的方法具有重要意义。

英文摘要：

Frequent welding faults and their harm during LED chips packaging are introduced. A typical blot welding fault of LED chips is studied, and its contact resistance and tunneling resistance are analyzed. The spectral characteristic and photocurrent of LED chips at the normal and fault welding are measured. The opto-electronic equivalent circuit of welding fault LED is proposed, and the experimental result is analyzed by the circuit. The experimental result shows that the light intensity and photocurrent of the welding fault LED chips are much less than that of the normal ones. It can detect the welding fault of LED chips by measuring the light intensity or photocurrent of LED chips. The research is important for improving the reliability of LED packaging and proposing the method of detecting welding faults during LED packaging.