Influence of observed anelasticity of Cu on the wafer warpage evolution during thermal processes

摘要：

　　Wafer warpage is becoming a more and more serious problem in wafer level package because there is a PI/Cu composite in the redistribution layer(RDL).The serious wafer warpage will affect the accuracy of subsequent processes,the wafer handle by mechanical arms,the adsorption of vacuum suction cup and device reliability.Previous work shows that copper and polyimide(PI)contributes almost equally to the wafer warpage in 2 metal 1 PI configuration.So the origin of wafer warpage and deformation mechanisms caused by Cu needs to be studied in detail.In this paper,the copper films are subjected to thermal cycles between 25℃ and 28℃,and the wafer warpage and temperature are recorded simultaneously.An obvious time delay between the peak temperature and the maximum warpage is detected,which is coincides with the initial small-slope stage at the beginning.Anelasticity is observed in copper film during the thermal pulse test,and annealing process has little effect on this phenomenon.

关键词： anelasticity of Cu wafer warpage hysteresis loop thermal cycles

作者: Gong Cheng Gaowei Xu Wei Gai Le Luo

作者单位: State Key Laboratory of Transducer Technology,Shanghai Institute of Microsystem and Information Tech State Key Laboratory of Transducer Technology,Shanghai Institute of Microsystem and Information Tech State Key Laboratory of Transducer Technology,Shanghai Institute of Microsystem and Information Tech

会议类型: 国际会议

会议名称: 第十九届国际电子封装技术会议(ICEPT 2018)

会议地点: 上海

会议语种:英文

页码: 1119-1122

在线出版日期: 2018-08-08（万方平台首次上网日期，不代表论文的发表时间）