塑封集成电路中铜丝键合的腐蚀及其评价

Corrosion and Evaluation of Copper Wire Bonding in Plastic Package of Integrated Circuit

腐蚀是影响塑封集成电路铜丝键合可靠性的重要因素,其与湿度、温度、Cl离子摩尔分数以及电位密切相关。针对NiPdAgAu预镀框架与纯铜丝第二键合点的腐蚀失效现象,研究其评价方法,并通过实际工况分析采用不同浓度的NaCl溶液进行预处理以及电位对腐蚀结果的影响。将样品置于质量分数分别为0.5%、2.0%与5.0%的NaCl溶液中,对其进行高温、高湿预处理24 h,再进行96 h的高加速应力试验。结果表明,采用质量分数为5.0%的NaCl溶液进行预处理对加速腐蚀更有效,且腐蚀的键合点多数位于低电位引脚,少数位于高电位引脚。

Corrosion is an important factor affecting reliability of copper wire bonding in plastic package of integrated circuit,which is closely related to humidity,temperature,Cl ion concentration and electric potential.In view of the corrosion failure of the second bonding point between NiPdAgAu pre-plated frame and pure copper wire,the evaluation method is studied,and the pretreatment with NaCl solution of different concentrations and the effect of potential on the corrosion results are analyzed through actual working conditions.The samples are placed in NaCl solution with concentrations of 0.5%,2.0%and 5.0%respectively.The samples are pretreated with high temperature and high humidity for 24 h,and then they are conducted high accelerated stress test for 96 h.The results show that the pretreatment with 5.0%NaCl solution is more effective in accelerating corrosion,and most of the corroded bonding points are located in the low electric potential pins,while a few are located in the high electric potential pins.