失效定位技术是发光二极管失效性分析中的重要组成部分, 本文在主流的3种失效定位技术:光子辐射显微技术、光诱导电阻变化、红外热成像显微技术的基础上, 提出了一种显微红外热点定位测试系统。该系统通过双线性插值算法使源图像放大至原来的4倍, 在使用20 μm微距镜头的条件下, 能达到与5 μm微距镜头接近的效果, 降低了LED失效检验成本。利用可见光图像和红外热像图的叠加, 提高电压对LED芯片失效点进行锁定, 能在大范围内迅速定位LED芯片缺陷所在。在此基础上, 结合FIB技术和SEM设备分析LED芯片微观结构, 可以进一步分析LED芯片的失效原因, 最终得到LED芯片的失效机理。实验结果表明, 在初步的缺陷定位中, 显微红外热点定位系统可快速地在无损条件下大范围区域内提供LED热数据分布, 定位关键失效点, 有效地提高了工作效率, 降低了失效检测成本。

The failure location technology is an important component of the LED failure analysis. In this paper, based on three main failure positioning technologies, namely, emission microscope(EMMI), optical beam induced resistance change(OBIRCH), and infrared thermal imaging(THERMAL), a micro infrared hot spot location system is proposed. By bilinear interpolation algorithm to enlarge the system source image magnification four times, under the condition of using 20-micron micro-lens, the system can achieve the effect close to 5-micron micro-lens, reduce the cost of the LED failure inspection by using the superposition of visible image and infrared thermal image. The LED chip failure point can be locked by increasing the voltage, which can quickly locate the LED chip defect in a wide range. On this basis, by combining FIB technology and SEM equipment to analyze the microstructure of LED chip, the failure reason of LED chip can be further analyzed, and finally the failure mechanism of LED chip can be obtained. The experimental results show that in the initial defect location, the micro-infrared hot spot location system can quickly provide the thermal data distribution of LED in a large area under non-destructive conditions and locate the key failure points, effectively improve work efficiency and reduce the cost of failure detection.