{"title":"In-situ observation on electrochemical migration of lead-free solder joints under water drop test","authors":"Y.H. Xia, W. Jillek, E. Schmitt","doi":"10.1109/ICEPT.2008.4607147","DOIUrl":null,"url":null,"abstract":"Electrochemical migration (ECM) of lead-free solder joints were investigated by water drop test method. Nine types solder pastes were employed to compare the ECM susceptible. The effects of applied voltage, electrodes spacing and flux residue on the ECM were in-situ observed. The microstructure and composition of the growing dendrites during ECM were detected. The results revealed that higher voltage and narrower spacing weakened the ECM reliability of solder joints. The flux residua inhibited the occurrence of ECM. The main migration element was Pb in Pb-bearing solder joints. For Sn-Ag-Cu solder joints, it was Sn and Cu to migrate during the ECM process. Zn was the only migration element in the SnZnBi solder joint. Sn-Zn-Bi solder exhibited the best ECM reliability.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":"100 1","pages":"1-5"},"PeriodicalIF":0.0000,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ICEPT.2008.4607147","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
Electrochemical migration (ECM) of lead-free solder joints were investigated by water drop test method. Nine types solder pastes were employed to compare the ECM susceptible. The effects of applied voltage, electrodes spacing and flux residue on the ECM were in-situ observed. The microstructure and composition of the growing dendrites during ECM were detected. The results revealed that higher voltage and narrower spacing weakened the ECM reliability of solder joints. The flux residua inhibited the occurrence of ECM. The main migration element was Pb in Pb-bearing solder joints. For Sn-Ag-Cu solder joints, it was Sn and Cu to migrate during the ECM process. Zn was the only migration element in the SnZnBi solder joint. Sn-Zn-Bi solder exhibited the best ECM reliability.
采用水滴法研究了无铅焊点的电化学迁移。采用9种焊锡膏对ECM的敏感性进行比较。现场观察了外加电压、电极间距和焊剂残留量对电解加工的影响。检测了ECM过程中生长枝晶的微观结构和组成。结果表明,较高的电压和较窄的间距降低了焊点的ECM可靠性。残流抑制了ECM的发生。含铅焊点的主要迁移元素是Pb。对于Sn- ag -Cu焊点,在ECM过程中主要是Sn和Cu的迁移。Zn是SnZnBi焊点中唯一的迁移元素。Sn-Zn-Bi焊料表现出最好的ECM可靠性。