{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T18:16:09Z","timestamp":1791483369149,"version":"4.3.4"},"reference-count":24,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,6,13]],"date-time":"2023-06-13T00:00:00Z","timestamp":1686614400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003093","name":"Ministry of Higher Education, Malaysia","doi-asserted-by":"publisher","award":["FRGS\/1\/2017\/TK05\/UNIMAP\/03\/3 (9003-00621)"],"award-info":[{"award-number":["FRGS\/1\/2017\/TK05\/UNIMAP\/03\/3 (9003-00621)"]}],"id":[{"id":"10.13039\/501100003093","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The growth and formation of primary intermetallics formed in Sn-3.5Ag soldered on copper organic solderability preservative (Cu-OSP) and electroless nickel immersion gold (ENIG) surface finish after multiple reflows were systematically investigated. Real-time synchrotron imaging was used to investigate the microstructure, focusing on the in situ growth behavior of primary intermetallics during the solid\u2013liquid\u2013solid interactions. The high-speed shear test was conducted to observe the correlation of microstructure formation to the solder joint strength. Subsequently, the experimental results were correlated with the numerical Finite Element (FE) modeling using ANSYS software to investigate the effects of primary intermetallics on the reliability of solder joints. In the Sn-3.5Ag\/Cu-OSP solder joint, the well-known Cu6Sn5 interfacial intermetallic compounds (IMCs) layer was observed in each reflow, where the thickness of the IMC layer increases with an increasing number of reflows due to the Cu diffusion from the substrate. Meanwhile, for the Sn-3.5Ag\/ENIG solder joints, the Ni3Sn4 interfacial IMC layer was formed first, followed by the (Cu, Ni)6Sn5 IMC layer, where the formation was detected after five cycles of reflow. The results obtained from real-time imaging prove that the Ni layer from the ENIG surface finish possessed an effective barrier to suppress and control the Cu dissolution from the substrates, as there is no sizeable primary phase observed up to four cycles of reflow. Thus, this resulted in a thinner IMC layer and smaller primary intermetallics, producing a stronger solder joint for Sn-3.5Ag\/ENIG even after the repeated reflow process relative to the Sn-3.5Ag\/Cu-OSP joints.<\/jats:p>","DOI":"10.3390\/ma16124360","type":"journal-article","created":{"date-parts":[[2023,6,14]],"date-time":"2023-06-14T02:01:40Z","timestamp":1686708100000},"page":"4360","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Effects of Multiple Reflow on the Formation of Primary Crystals in Sn-3.5Ag and Solder Joint Strength: Experimental and Finite Element Analysis"],"prefix":"10.3390","volume":"16","author":[{"given":"Siti Farahnabilah Muhd","family":"Amli","sequence":"first","affiliation":[{"name":"Center of Excellence Geopolymer & Green Technology (CeGeoGTech), University Malaysia Perlis (UniMAP), Taman Muhibbah, Kangar 02600, Malaysia"},{"name":"Faculty of Chemical Engineering Technology, University Malaysia Perlis (UniMAP), Taman Muhibbah, Kangar 02600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohd Arif Anuar Mohd","family":"Salleh","sequence":"additional","affiliation":[{"name":"Center of Excellence Geopolymer & Green Technology (CeGeoGTech), University Malaysia Perlis (UniMAP), Taman Muhibbah, Kangar 02600, Malaysia"},{"name":"Faculty of Chemical Engineering Technology, University Malaysia Perlis (UniMAP), Taman Muhibbah, Kangar 02600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3271-9242","authenticated-orcid":false,"given":"Mohd Sharizal Abdul","family":"Aziz","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, University Sains Malaysia, Nibong Tebal, Gelugor 14300, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hideyuki","family":"Yasuda","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0721-6600","authenticated-orcid":false,"given":"Kazuhiro","family":"Nogita","sequence":"additional","affiliation":[{"name":"Nihon Superior Centre for the Manufacture of Electronic Materials (NS CMEM), School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, QLD 4072, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohd Mustafa Al Bakri","family":"Abdullah","sequence":"additional","affiliation":[{"name":"Center of Excellence Geopolymer & Green Technology (CeGeoGTech), University Malaysia Perlis (UniMAP), Taman Muhibbah, Kangar 02600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7332-9331","authenticated-orcid":false,"given":"Ovidiu","family":"Nemes","sequence":"additional","affiliation":[{"name":"Department of Environmental Engineering and Sustainable Development Entrepreneurship, Faculty of Materials and Environmental Engineering, Technical University of Cluj-Napoca, B-dul Muncii 103-105, 400641 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9292-749X","authenticated-orcid":false,"given":"Andrei Victor","family":"Sandu","sequence":"additional","affiliation":[{"name":"Faculty of Materials Science and Engineering, Gheorghe Asachi Technical University of Iasi, Blvd. D. Mangeron 71, 700050 Iasi, Romania"},{"name":"Romanian Inventors Forum, Str. Sf. P. Movila 3, 700089 Iasi, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3593-9400","authenticated-orcid":false,"given":"Petrica","family":"Vizureanu","sequence":"additional","affiliation":[{"name":"Faculty of Materials Science and Engineering, Gheorghe Asachi Technical University of Iasi, Blvd. D. Mangeron 71, 700050 Iasi, Romania"},{"name":"Technical Sciences Academy of Romania, Dacia Blvd 26, 030167 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,6,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1207","DOI":"10.1007\/s11664-000-0014-7","article-title":"Effect of soldering and aging time on interfacial microstructure and growth of intermetallic compounds between Sn-3.5 Ag solder alloy and Cu substrate","volume":"29","author":"Choi","year":"2000","journal-title":"J. Electron. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/S0921-5107(04)00406-4","article-title":"Interfacial reactions of BGA Sn\u20133.5% Ag\u20130.5% Cu and Sn\u20133.5% Ag solders during high-temperature aging with Ni\/Au metallization","volume":"113","author":"Sharif","year":"2004","journal-title":"Mater. Sci. Eng. 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