摘要
【目的】为研究高银系(Ag质量分数大于3.0%)Sn-Ag-Cu在固相时效过程中的界面反应和生长动力学。【方法】高温条件下不同银含量对界面结构和界面生长的影响,为了确定焊点的长期可靠性,在150℃下进行了0 h,100 h,300 h,500 h的热加速老化试验。用SEM与EDS进行了IMC表面形貌、厚度和元素组成。【结果】研究结果表明,随着银含量的增加,Cu_(6)Sn_(5)的生长受到不同程度抑制。在等温时效过程中,金属间化合物(IMC,Cu_(6)Sn_(5)+Cu_(3)Sn)的生长动力学是一个扩散控制过程,Cu_(6)Sn_(5)逐渐生长为Cu_(3)Sn;在后期的老化阶段,扇贝状的形状消失,表明生长机制发生了变化,变化为向垂直于界面方向的稳定生长;通过有限元技术,得出在服役过程中,热应力主要集中于Cu_(3)Sn与Cu基板交界处;随着时效时间的增加,焊点等效蠕变应变上升,可靠性逐渐降低;利用阿仑尼乌斯公式计算了金属间化合物IMC(Cu_(6)Sn_(5)+Cu_(3)Sn)在界面Sn-3.0Ag-0.7Cu/Cu,Sn-3.4Ag-0.7Cu/Cu,Sn-3.8Ag-0.7Cu/Cu的表观活化能分别为67.13 kJ/mol,70.50 kJ/mol,69.54 kJ/mol。【结论】根据试验与数值模拟计算相结合的研究手段,得到Sn-3.4Ag-0.7Cu款无铅焊料在高温服役过程中比其他焊料更能满足电子元件的要求。
[Objective]The interfacial reaction and growth kinetics of high silver series Sn-Ag-Cu during solid phase aging were studied.[Methods]The effects of different silver contents on the interfacial structure and interfacial growth at high temperature were investigated experimentally and numerically.In order to determine the long-term reliability of solder joints,thermal accelerated aging tests were carried out at 150℃for 0 h,100 h,300 h,500 h.The surface morphology,thickness and elemental composition of IMC were investigated by SEM and EDS.[Results]The results showed that the growth of Cu_(6)Sn_(5) was inhibited with the increase of silver content.In the isothermal aging process,the growth kinetics of intermetallic compounds(IMC,Cu_(6)Sn_(5)+Cu_(3)Sn)is a diffusion control process.Cu_(6)Sn_(5) gradually grows into Cu_(3)Sn.In the later aging stage,the scallop-like shape disappears,indicating that the growth mechanism has changed,and the change is stable growth in the direction vertical to the interface.Through the finite element technique,it is concluded that the thermal stress is mainly concentrated at the junction of Cu_(3)Sn and Cu substrate during service.With the increase of aging time,the equivalent creep strain of solder joint rises and the reliability decreases gradually.The apparent activation energies of intermetallic compound IMC(Cu_(6)Sn_(5)+Cu_(3)Sn)at the interface Sn-3.0Ag-0.7 Cu/Cu,Sn-3.4Ag-0.7Cu/Cu and Sn-3.8Ag-0.7Cu/Cu are 67.13 kJ/mol,70.50 kJ/mol,69.54 kJ/mol.[Conclusion]Respectively,according to arrinius formula,Sn-3.4Ag-0.7Cu/Cu is better than other solder joint components to meet the requirements of electronic components.
作者
张欣
秦俊虎
龙登成
梁东成
严继康
Zhang Xin;Qin Junhu;Long Dengcheng;Liang Dongcheng;Yan Jikang(Yunnan Tin Industry Tin Material Co.,Ltd.,Kunming 650501,China;Kunming University of Science and Technology,Kunming 650093,China;Southwest Petroleum University,Nanchong 637001,Sichuan,China)
出处
《焊接》
2024年第8期38-46,共9页
Welding & Joining
基金
云南省电子贴装用锡焊料系列产品开发项目(2018ZE004)
云南锡业锡材有限公司汽车电子用高可靠焊料合金开发及应用研究省创新团队项目(202105AE160028)。
