The roles of dendritic spacings and Ag3Sn intermetallics on hardness of the SAC307 solder alloy

Autor(es)

Silva, Bismarck Luiz ^[1] ; Garcia, Amauri ^[2] ; Spinelli, Jose Eduardo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Estadual Campinas, Dept Mfg & Mat Engn, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MICROELECTRONICS RELIABILITY; v. 54, n. 12, p. 2929-2934, DEC 2014.
• Citações Web of Science: 5

Resumo

Sn-Ag-Cu alloys have emerged as the most promising lead-free solder series among a number of alternatives. These alloys generally present a dendritic Sn-rich matrix surrounded by a eutectic mixture (beta + alpha), where beta is the Sn-rich phase and alpha is the Ag3Sn intermetallic compound. The present study aims to investigate the effects of dendritic (lambda(2), lambda(3)) and eutectic (lambda) spacings and the morphology of Ag3Sn particles on hardness of the Sn-3.0 wt%Ag-0.7 wt%Cu alloy (SAC307). In order to establish correlations between lambda(2,3) and hardness, transient directional solidification (DS) experiments were performed permitting a wide range of different microstructures to be examined. The techniques used for microstructure characterization included dissolution of the Sn-rich matrix, optical/scanning electron microscopy. A dendritic microstructure prevailed in the entire DS casting. It is shown that the hardness tends to decrease with the increase in lambda(2), lambda(3) and lambda(F) (eutectic spacing for Ag3Sn having a fiber morphology). Experimental equations relating microstructural spacings to hardness are proposed. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 13/13030-5 - Microestrutura, parâmetros térmicos, segregação e propriedades mecânicas de ligas alternativas de soldagem à base de Sn, Zn e Bi
• Beneficiário: José Eduardo Spinelli
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/08259-3 - Desenvolvimento microestrutural e do comportamento mecânico de ligas alternativas de soldagem Sn-Bi-Cu e Sn-Bi-Ag
• Beneficiário: Bismarck Luiz Silva
• Linha de fomento: Bolsas no Brasil - Doutorado