{"title":"共晶PbSn预焊基板上95高铅凸点的基础研究","authors":"Chih-Chiang. Chang, Chun-Cheng Lin, C. Kao","doi":"10.1109/IMPACT.2009.5382312","DOIUrl":null,"url":null,"abstract":"This study investigated the intermixing of 95Pb5Sn solder bumps and 37Pb63Sn pre-solder in flip-chip solder joints. The reaction conditions included multiple reflows (up to 10) at 240 °C, whereby previously solder-coated parts are joined by heating without using additional solder. We found that the molten pre-solder had an irregular shape similar to a calyx (i.e., a cuplike structure) wrapped around a high-lead solder bump. The height to which the molten pre-solder ascended along the solid high-lead solder bump increased with the number of reflows. The molten pre-solder was able to reach the UBM/95Pb5Sn interface after three to five reflows. The molten pre-solder at the UBM/95Pb5Sn interface generated two important phenomena: (1) the molten solder dewetted (i.e., flowed away from the soldered surface) along the UBM/95Pb5Sn interface, particularly when the number of reflows was high, and (2) the molten pre-solder transported Cu atoms to the UBM/95Pb5Sn interface, which in turn caused the Ni-Sn compounds at the chip-side interface to change into (Cu0.6Ni0.4)6Sn5.","PeriodicalId":6410,"journal":{"name":"2009 4th International Microsystems, Packaging, Assembly and Circuits Technology Conference","volume":"103 1","pages":"72-75"},"PeriodicalIF":0.0000,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Fundamental study of 95 high-lead solder bump on substrates pre-soldered with eutectic PbSn\",\"authors\":\"Chih-Chiang. Chang, Chun-Cheng Lin, C. Kao\",\"doi\":\"10.1109/IMPACT.2009.5382312\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"This study investigated the intermixing of 95Pb5Sn solder bumps and 37Pb63Sn pre-solder in flip-chip solder joints. The reaction conditions included multiple reflows (up to 10) at 240 °C, whereby previously solder-coated parts are joined by heating without using additional solder. We found that the molten pre-solder had an irregular shape similar to a calyx (i.e., a cuplike structure) wrapped around a high-lead solder bump. The height to which the molten pre-solder ascended along the solid high-lead solder bump increased with the number of reflows. The molten pre-solder was able to reach the UBM/95Pb5Sn interface after three to five reflows. The molten pre-solder at the UBM/95Pb5Sn interface generated two important phenomena: (1) the molten solder dewetted (i.e., flowed away from the soldered surface) along the UBM/95Pb5Sn interface, particularly when the number of reflows was high, and (2) the molten pre-solder transported Cu atoms to the UBM/95Pb5Sn interface, which in turn caused the Ni-Sn compounds at the chip-side interface to change into (Cu0.6Ni0.4)6Sn5.\",\"PeriodicalId\":6410,\"journal\":{\"name\":\"2009 4th International Microsystems, Packaging, Assembly and Circuits Technology Conference\",\"volume\":\"103 1\",\"pages\":\"72-75\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2009-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"2009 4th International Microsystems, Packaging, Assembly and Circuits Technology Conference\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/IMPACT.2009.5382312\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"2009 4th International Microsystems, Packaging, Assembly and Circuits Technology Conference","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/IMPACT.2009.5382312","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Fundamental study of 95 high-lead solder bump on substrates pre-soldered with eutectic PbSn
This study investigated the intermixing of 95Pb5Sn solder bumps and 37Pb63Sn pre-solder in flip-chip solder joints. The reaction conditions included multiple reflows (up to 10) at 240 °C, whereby previously solder-coated parts are joined by heating without using additional solder. We found that the molten pre-solder had an irregular shape similar to a calyx (i.e., a cuplike structure) wrapped around a high-lead solder bump. The height to which the molten pre-solder ascended along the solid high-lead solder bump increased with the number of reflows. The molten pre-solder was able to reach the UBM/95Pb5Sn interface after three to five reflows. The molten pre-solder at the UBM/95Pb5Sn interface generated two important phenomena: (1) the molten solder dewetted (i.e., flowed away from the soldered surface) along the UBM/95Pb5Sn interface, particularly when the number of reflows was high, and (2) the molten pre-solder transported Cu atoms to the UBM/95Pb5Sn interface, which in turn caused the Ni-Sn compounds at the chip-side interface to change into (Cu0.6Ni0.4)6Sn5.