{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34573"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34573","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Microstructural Evolution in Thermally Cycled Large-Area Lead and Lead-Free Solder Joints","abstract":"Currently, there are two major driving forces for considering alternative materials to lead- based products, specifically interconnections, in electronics applications, including the impending legislation or regulations which may tax, restrict, or eliminate the use of lead and the trend toward advanced interconnection technology, which may challenge the limits of present soldering technology. The reliability of solder joints is a concern because fracture failures in solder joints accounts for 70% of failures in electronic components. Lead-free solders are being investigated as replacements for lead solders currently used in electronics. Thermo-mechanical properties describe the stresses accumulated due to thermal fatigue as a result of CTE mismatch within the system. By understanding the failure mechanisms related to lead-free solders, the application of lead- free solders could be more strategically designed for specific applications. The objective of this thesis is to observe microstructural change in large-area solder joints caused by thermal cycling and relate these changes to reliability issues in large-area lead and lead-free solder constructed semiconductor power devices. This study focused on the microstructural changes within the solder alloy of a large-area solder joint under thermal cycling conditions. Two major primary observations were made from this research, they are: 1) due to a combination of testing conditions and material properties, the lead-free solders, Sn/3.5Ag and Sn/Ag/0.7Cu, sustained the most severe damage as compared to Sn/37Pb, and 2) due to elevated stresses at the solder/substrate interface in a simulated power semiconductor device sample damage was found to be most severe.","abstract_html":"Currently, there are two major driving forces for considering alternative materials to lead- based products, specifically interconnections, in electronics applications, including the impending legislation or regulations which may tax, restrict, or eliminate the use of lead and the trend toward advanced interconnection technology, which may challenge the limits of present soldering technology. The reliability of solder joints is a concern because fracture failures in solder joints accounts for 70% of failures in electronic components. Lead-free solders are being investigated as replacements for lead solders currently used in electronics. Thermo-mechanical properties describe the stresses accumulated due to thermal fatigue as a result of CTE mismatch within the system. By understanding the failure mechanisms related to lead-free solders, the application of lead- free solders could be more strategically designed for specific applications. The objective of this thesis is to observe microstructural change in large-area solder joints caused by thermal cycling and relate these changes to reliability issues in large-area lead and lead-free solder constructed semiconductor power devices. This study focused on the microstructural changes within the solder alloy of a large-area solder joint under thermal cycling conditions. Two major primary observations were made from this research, they are: 1) due to a combination of testing conditions and material properties, the lead-free solders, Sn/3.5Ag and Sn/Ag/0.7Cu, sustained the most severe damage as compared to Sn/37Pb, and 2) due to elevated stresses at the solder/substrate interface in a simulated power semiconductor device sample damage was found to be most severe.","abstract_has_math":false,"creators":["Stinson-Bagby, Kelly Lucile"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Science and Engineering","degree_department":"Materials Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Lu, Guo-Quan"],"committee_members":["Reynolds, William T. Jr.","van Wyk, Jacobus Daniel"],"year":2002,"date_issued":"2002-06-07","date_published":"2002-06-07","updated_at":"2026-07-22T22:20:34Z","subjects":["Microstructural Evolution","Thermal Aging","Lead-Free Solder","Reliability","Large-Area Solder Bond","Thermal Cycling","Die Attach"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08162002-132705"],"render_values":[{"text":"etd-08162002-132705","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34573","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Lu, Guo-Quan"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Reynolds, William T. 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The reliability of solder joints is a concern because fracture failures in solder joints accounts for 70% of failures in electronic components. Lead-free solders are being investigated as replacements for lead solders currently used in electronics. Thermo-mechanical properties describe the stresses accumulated due to thermal fatigue as a result of CTE mismatch within the system. By understanding the failure mechanisms related to lead-free solders, the application of lead- free solders could be more strategically designed for specific applications. The objective of this thesis is to observe microstructural change in large-area solder joints caused by thermal cycling and relate these changes to reliability issues in large-area lead and lead-free solder constructed semiconductor power devices. This study focused on the microstructural changes within the solder alloy of a large-area solder joint under thermal cycling conditions. Two major primary observations were made from this research, they are: 1) due to a combination of testing conditions and material properties, the lead-free solders, Sn/3.5Ag and Sn/Ag/0.7Cu, sustained the most severe damage as compared to Sn/37Pb, and 2) due to elevated stresses at the solder/substrate interface in a simulated power semiconductor device sample damage was found to be most severe."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Microstructural Evolution in Thermally Cycled Large-Area Lead and Lead-Free Solder Joints"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Lu, Guo-Quan"],"dc:contributor.committeemember":["Reynolds, William T. Jr.","van Wyk, Jacobus Daniel"],"dc:contributor.department":["Materials Science and Engineering"],"dc:creator":["Stinson-Bagby, Kelly Lucile"],"dc:date.accessioned":["2014-03-14T20:43:34Z"],"dc:date.available":["2014-03-14T20:43:34Z","2003-08-23"],"dc:date.issued":["2002-06-07"],"dc:description.abstract":["Currently, there are two major driving forces for considering alternative materials to lead- based products, specifically interconnections, in electronics applications, including the impending legislation or regulations which may tax, restrict, or eliminate the use of lead and the trend toward advanced interconnection technology, which may challenge the limits of present soldering technology. The reliability of solder joints is a concern because fracture failures in solder joints accounts for 70% of failures in electronic components. Lead-free solders are being investigated as replacements for lead solders currently used in electronics. Thermo-mechanical properties describe the stresses accumulated due to thermal fatigue as a result of CTE mismatch within the system. By understanding the failure mechanisms related to lead-free solders, the application of lead- free solders could be more strategically designed for specific applications. The objective of this thesis is to observe microstructural change in large-area solder joints caused by thermal cycling and relate these changes to reliability issues in large-area lead and lead-free solder constructed semiconductor power devices. This study focused on the microstructural changes within the solder alloy of a large-area solder joint under thermal cycling conditions. Two major primary observations were made from this research, they are: 1) due to a combination of testing conditions and material properties, the lead-free solders, Sn/3.5Ag and Sn/Ag/0.7Cu, sustained the most severe damage as compared to Sn/37Pb, and 2) due to elevated stresses at the solder/substrate interface in a simulated power semiconductor device sample damage was found to be most severe."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-08162002-132705"],"dc:identifier.uri":["http://hdl.handle.net/10919/34573"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Microstructural Evolution","Thermal Aging","Lead-Free Solder","Reliability","Large-Area Solder Bond","Thermal Cycling","Die Attach"],"dc:title":["Microstructural Evolution in Thermally Cycled Large-Area Lead and Lead-Free Solder Joints"],"dc:type":["Thesis"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:34Z"}