Depressing effect of 0.1 wt.% Cr addition into Sn-9Zn solder alloy on the intermetallic growth with Cu substrate during isothermal aging

Journal Article · Mon Mar 15 04:00:00 EDT 2010 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2009.12.019· OSTI ID:22066192

Jin, Hu ^[1]; Ming, Li; Dali, Mao ^[1]

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1. State Key Lab Met Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai, 200240 (China)

In this paper, the effect of 0.1 wt.% Cr addition into Sn-9Zn lead-free solder alloys on the growth of intermetallic compound (IMC) with Cu substrate during soldering and subsequent isothermal aging was investigated. During soldering, it was found that 0.1 wt.% Cr addition did not contribute to forming the IMC, which was verified as the same phase structure as the IMC for Sn-9Zn/Cu. However, during solid-state isothermal aging, the IMC growth was remarkably depressed by 0.1 wt.% Cr addition in the Sn-9Zn solder, and this effect tended to be more prominent at higher aging temperature. The activation energy for IMC growth was determined as 21.2 kJ mol{sup -1} and 42.9 kJ mol{sup -1} for Sn-9Zn/Cu and Sn-9Zn-Cr/Cu, respectively. The reduced diffusion coefficient was confirmed for the 0.1Cr-containing solder/Cu. Energy-dispersive X-ray mapping and point analysis also showed ZnCr phase existing in solder matrix, which can reduce diffusion rate of Zn atoms.

• OSTI ID: 22066192
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 3 Vol. 61; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
AGING
CHROMIUM ADDITIONS
COPPER
CRYSTAL GROWTH
DIFFUSION
INTERFACES
INTERMETALLIC COMPOUNDS
MATRIX MATERIALS
SOLDERING
SOLIDS
SUBSTRATES
TIN
X-RAY SPECTROSCOPY
ZINC