Microstructure, thermal parameters, segregation and mechanical properties of lead-free Sn-based, Zn-based and Bi-based solder alloys

• Grant number: 13/13030-5
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2013
• End date: October 31, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: José Eduardo Spinelli
• Grantee: José Eduardo Spinelli
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

New legislations have been continuously launched by the European Union (EU) in order to avoid the usage of hazardous substances on microelectronics. Other important countries like Japan and China have already adopted such restrictions. The specific element to be evaluated in the present proposal is lead (Pb), which is considered one of the six substances with higher toxic potential. The usage of lead-based or lead-containing materials in processes like soldering tends to be completely banned. As a consequence, development and understanding of alternative alloys become essential priority for industry on microelectronics. As soldering is based on joining parts through melting/solidification route, all events involving solidification are of interest, i.e., nucleation, heat transfer, microstructure, solute distribution, segregation and defects. Such aspects must be comprehended so that demands on project of connected circuits could be attained. The control of structure and intermetallics are pointed as critical parameters considering soldered parts. Some lead-free solders have been chosen for the present project: Bi-Sn and Bi-Ag - need of improve mechanical properties through the control of microstructure; Zn-Sn - due to the large freezing range large segregation is expected. How to control it? Sn-Bi-Cu and Sn-Bi-Ag - effects of Bi adding on the properties of the commercial Sn-Cu and S-Ag eutectics. The present study aims to use facilities on directional solidification with a view to better comprehend: i. the effects of solidification thermal variables on the as-cast structure of several solder alloys, including formation of primary phases, eutectics and intermetallics; ii. the segregation levels considering cooling rate values equivalent to those experienced in real processes; iii. variation of mechanical properties as a function of temperature, solute content and microstructure. (AU)

Scientific publications

(14)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SPINELLI, JOSE EDUARDO; SILVA, BISMARCK LUIZ; GARCIA, AMAURI. Microstructure, phases morphologies and hardness of a Bi-Ag eutectic alloy for high temperature soldering applications. MATERIALS & DESIGN, v. 58, p. 482-490, JUN 2014. (13/13030-5)

SILVA, BISMARCK LUIZ; BERTELLI, FELIPE; CANTE, MANUEL V.; SPINELLI, JOSE E.; CHEUNG, NOE; GARCIA, AMAURI. Solder/substrate interfacial thermal conductance and wetting angles of Bi-Ag solder alloys. JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, v. 27, n. 2, p. 1994-2003, FEB 2016. (13/13030-5, 13/08259-3)

SILVA, BISMARCK LUIZ; GARCIA, AMAURI; SPINELLI, JOSE EDUARDO. The roles of dendritic spacings and Ag3Sn intermetallics on hardness of the SAC307 solder alloy. MICROELECTRONICS RELIABILITY, v. 54, n. 12, p. 2929-2934, DEC 2014. (13/13030-5, 13/08259-3)

SILVA, BISMARCK LUIZ; CHEUNG, NOE; GARCIA, AMAURI; SPINELLI, JOSE EDUARDO. Evaluation of solder/substrate thermal conductance and wetting angle of Sn-0.7 wt%Cu-(0-0.1 wt%Ni) solder alloys. Materials Letters, v. 142, p. 163-167, MAR 1 2015. (13/13030-5, 13/08259-3)

SILVA, BISMARCK LUIZ; REINHART, GUILLAUME; NGUYEN-THI, HENRI; MANGELINCK-NOEL, NATHALIE; GARCIA, AMAURI; SPINELLI, JOSE EDUARDO. Microstructural development and mechanical properties of a near-eutectic directionally solidified Sn-Bi solder alloy. MATERIALS CHARACTERIZATION, v. 107, p. 43-53, SEP 2015. (13/13030-5, 13/08259-3)

SANTOS, WASHINGTON L. R.; BRITO, CRYSTOPHER; BERTELLI, FELIPE; SPINELLI, JOSE E.; GARCIA, AMAURI. Microstructural development of hypoeutectic Zn-(10-40)wt%Sn solder alloys and impacts of interphase spacing and macrosegregation pattern on hardness. Journal of Alloys and Compounds, v. 647, p. 989-996, OCT 25 2015. (13/13030-5, 12/08494-0, 12/16328-2)

SPINELLI, JOSE EDUARDO; SILVA, BISMARCK LUIZ; GARCIA, AMAURI. Assessment of Tertiary Dendritic Growth and Its Effects on Mechanical Properties of Directionally Solidified Sn-0.7Cu-xAg Solder Alloys. JOURNAL OF ELECTRONIC MATERIALS, v. 43, n. 5, p. 1347-1361, MAY 2014. (13/13030-5, 13/08259-3)

FREITAS, EMMANUELLE S.; SILVA, ADRINA P.; SPINELLI, JOSE E.; CASTELETTI, LUIZ C.; GARCIA, AMAURI. Inter-relation of Microstructural Features and Dry Sliding Wear Behavior of Monotectic Al-Bi and Al-Pb Alloys. TRIBOLOGY LETTERS, v. 55, n. 1, p. 111-120, JUL 2014. (13/13030-5, 13/15478-3)

FREITAS, EMMANUELLE S.; OSORIO, WISLEI R.; SPINELLI, JOSE E.; GARCIA, AMAURI. Mechanical and corrosion resistances of a Sn-0.7 wt.%Cu lead-free solder alloy. MICROELECTRONICS RELIABILITY, v. 54, n. 6-7, p. 1392-1400, JUN-JUL 2014. (13/13030-5, 13/15478-3)

SPINELLI, JOSE EDUARDO; SILVA, BISMARCK LUIZ; CHEUNG, NOE; GARCIA, AMAURI. The use of a directional solidification technique to investigate the interrelationship of thermal parameters, microstructure and microhardness of Bi-Ag solder alloys. MATERIALS CHARACTERIZATION, v. 96, p. 115-125, OCT 2014. (13/13030-5, 13/08259-3)

SILVA, BISMARCK L.; GARCIA, AMAURI; SPINELLI, JOSE E.. Cooling thermal parameters and microstructure features of directionally solidified ternary Sn-Bi-(Cu,Ag) solder alloys. MATERIALS CHARACTERIZATION, v. 114, p. 30-42, APR 2016. (13/13030-5, 13/08259-3)

SILVA, BISMARCK LUIZ; CHEUNG, NOE; GARCIA, AMAURI; SPINELLI, JOSE EDUARDO. Sn-0.7 wt%Cu-(xNi) alloys: Microstructure-mechanical properties correlations with solder/substrate interfacial heat transfer coefficient. Journal of Alloys and Compounds, v. 632, p. 274-285, MAY 25 2015. (13/13030-5, 13/08259-3)

SILVA, BISMARCK LUIZ; SPINELLI, JOSE EDUARDO; CANTE, MANUEL V.; BERTELLI, FELIPE; CHEUNG, NOE; RIVA, RUDIMAR; GARCIA, AMAURI. Experimental and numerical analyses of laser remelted Sn-0.7 wt% Cu solder surfaces. JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, v. 26, n. 5, p. 3100-3107, MAY 2015. (13/13030-5, 12/16328-2)

SPINELLI, JOSE EDUARDO; SILVA, BISMARCK LUIZ; GARCIA, AMAURI. Microstructure, phases morphologies and hardness of a Bi-Ag eutectic alloy for high temperature soldering applications. MATERIALS & DESIGN, v. 58, p. 9-pg., 2014-06-01. (13/13030-5)