Creep Behavior and Deformation Mechanism Map of Sn-Pb Eutectic Solder Alloy

Abstract

In this study, a large number of creep tests were carried out using miniature specimens in order to investigate the creep behavior of 63Sn/37Pb eutectic solder alloy over a wide temperature range from −40 to 150°C and stress range from 0.75 to 70 MPa. Based on dislocation and diffusion theories, two unified constitutive models were developed to describe the dislocation-controlled and diffusion-controlled creep behaviors observed. It was found that the two models accurately predict the experimental data. A deformation mechanism map was established for this eutectic solder alloy in order to interpret the creep mechanism under different temperature and loading conditions.

Reliability Assessment of Microelectronics Packages Using Dynamic Testing Methods

“…Therefore, the stress-strain curves obtained at the strain rate of 2.78 × 10 −1 were employed in current FEMs to calculate the time-independent plastic strain of the solder. The creep strain rate is given as [15] …”

In Situ Optical Creep Observation of Joint-Scale Tin–Silver–Copper Solder Shear Samples

“…The formation of subgrains may be attributed to recrystallization or recovery during creep, which has been reported for solders, namely during thermal cycling at locations where strain concentration occurred. 12,13,27 The grain boundaries seen in Figs. 8c and 9c show that recrystallization is part of creep during shear deformation under the applied conditions and facilitates the propagation of intergranular fracture.…”

“…Comparable stress and temperature dependence of deformation mechanisms has been reported for Sn-Pb solders. 12 A summary of the mechanisms based on the observations from Tables II and III is shown in Tables IV and V. The key is as follows:…”

“…Creep mechanisms have been investigated for metals and some solders, such as eutectic Sn-Pb 12 and lead-free Sn-3.5Ag-Bi. 13 No data was found investigating the creep mechanisms of SAC solder alloys subjected to constant-temperature, constantstress or constant-strain-rate shear deformation.…”

A Unified Creep-Fatigue Equation with Application to Engineering Design

“…The coefficients of the unified formulation for 63Sn37Pb solder is shown in Table 1 based on the creep-rupture data [16] and creep-fatigue data [5]. This material was validated in our previous research [11], but the coefficients are recalculated here since the derivation method was further improved in the present work.…”