Superplastic Creep of Eutectic Tin-Lead Solder Joints

Conference · Sat Jun 01 04:00:00 EDT 1991 · Journal of Electronic Packaging

DOI:https://doi.org/10.1115/1.2905375· OSTI ID:6229156

Mei, Z. ^[1]; Shine, M. C. ^[2]; Morris, Jr., J. W. ^[1]

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1. Lawrence Berkeley Laboratory (LBL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
2. Digital Equipment Corporation, Cupertino, CA (United States)

The creep behavior of air-cooled and liquid nitrogen-quenched soldered joints of 60/40 Sn-Pb at 65°C has been studied. The stress exponent, n, in the power law, γ˙ (steady state strain rate) ∝σⁿ (applied stress), changes from a value of about 6 to values of 2 to 3, as γ˙ decreases below 10^-4 in/in per second. This result, combined with the authors’ previous stepped load creep test results, indicates a transition of the creep deformation mechanism from conventional dislocation climb to superplastic grain boundary sliding. The superplastic creep of the soldered joints is ascribed to their non-lamellar microstructure due to their fast-cooling rate. During creep deformation, recrystallization of the soldered joints occurs, causing softening.

• Research Organization: Lawrence Berkeley Laboratory (LBL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6229156
• Report Number(s): LBL--29614; CONF-901194--14; ON: DE91009074
• Conference Information: Journal Name: Journal of Electronic Packaging Journal Issue: 2 Journal Volume: 113
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CREEP
CRYSTAL STRUCTURE
FATIGUE
JOINTS
LEAD ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
RECRYSTALLIZATION
SOLDERED JOINTS
TIN ALLOYS
TIN BASE ALLOYS