激光开封和化学开封在失效分析中的应用

Application of Laser and Chemical Unsealing in Failure Analysis

阐述使用激光开封与化学开封相结合的新开封工艺,对塑封器件进行开封实验。根据塑封器件特性,利用激光开封设备对芯片上方的塑封料进行减薄,再结合手动化学开封去除器件塑封料。实验结果表明,减薄至引线与芯片表面焊点位置出现且芯片未暴露的状态可以避免激光刻蚀对芯片的损伤,同时保持芯片功能完好。结合工艺能有效保留器件封装前后的形貌和电性特征,避免采用单一开封模式造成的缺陷,同时还具备效率高,成本低等优点。

In this paper,a new unsealing process combining laser unsealing with chemical unsealing is described to conduct unsealing experiments on plastic packaging devices.According to the characteristics of the plastic packaging device,the laser unsealing device is used to thin the plastic packaging material above the chip,and then combined with manual chemical unsealing to remove the plastic packaging material of the device.The experimental results show that thinning to the position where the solder joint between the lead wire and the chip surface appears and the chip is not exposed can avoid the damage of the chip caused by laser etching,while keeping the chip function intact.The combined process can effectively preserve the morphology and electrical characteristics of devices before and after packaging,avoid the defects caused by single opening mode,and has the advantages of high efficiency and low cost.