MPD芯片高温老化试验后的失效分析

Failure Analysis of MPD Chip after High Temperature Burn-in Test

对光模块在高温老化可靠性试验中,出现的激光器的背光探测器(MPD)芯片失效的现象进行了分析。首先,通过PIV测试仪、高倍显微镜和扫描电镜等手段对激光器中的MPD芯片失效原因进行了分析。结果表明,该芯片失效的原因为:导电胶在高温老化过程出现银迁移现象,芯片正负极之间逐渐形成导电通路,从而导致失效器件中的背光MPD的PN结热击穿,进而造成整颗芯片烧毁。然后,分析了银迁移的机理。最后,从工艺控制、产品检测和设备调试3个方面提出了改进措施,对于降低此类失效现象发生的风险,提高MPD芯片封装的可靠性具有重要的参考价值。

The failure of MPD chip of laser during high temperature burn-in reliability test of optical module is analyzed.Firstly,the failure cause of MPD chip of laser is analyzed by means of PIV tester,high power microscope and scanning electron microscope.The results show that the reason for the failure of the chip is that silver migration occurs during the high-temperature burn-in process of the conductive adhesive,and conductive path is gradually formed between the positive and negative electrodes of the chip,which leads to thermal breakdown of the PN junction of the MPD in the failed device,and then the whole chip burns.Next,the mechanism of silver migration is analyzed.Finally,improvement measures are proposed from three aspects,such as process control,product testing and equipment debugging,which has important reference value for reducing the risk of such failure phenomenon and improving the reliability of MPD chip packaging.