Determination of Anand parameters for SnAgCuCe solder

Abstract

A unified viscoplastic constitutive model, Anand equations, was used to represent the inelastic deformation behavior for Sn3.8Ag0.7Cu/Sn3.8Ag0.7 Cu0.03Ce solders in surface mount technology. The Anand parameters of the constitutive equations for the SnAgCu and SnAgCuCe solders were determined from separated constitutive relations and experimental results. Non-linear least-squares fitting was selected to determine the model constants. Comparisons were then made with experimental measurements of the stress–inelastic strain curves: excellent agreement was found. The model accurately predicted the overall trend of steady-state stress–strain behavior of SnAgCu and SnAgCuCe solders for the temperature ranges from −55 to 125 °C and for the strain rate range from 1% s−1 to 0.01% s−1. It is concluded that the Anand model can be applied to represent the inelastic deformation behavior of solders at high homologous temperatures and can be recommended for finite element simulation of the stress–strain response of lead-free soldered joints. Based on the Anand model, the investigations of thermo-mechanical behavior of SnAgCu and SnAgCuCe soldered joints in fine pitch quad flat package by the finite element code have been done under thermal cyclic loading, and it is found that the reliability of the SnAgCuCe soldered joints is better than that of the SnAgCu soldered joints.

(Project 13-5292) Correlating thermal and mechanical coupling based multiphysics behavior of nuclear materials through in-situ measurements

“…Traditionally, the Anand viscoplastic model has been used to characterize the high temperature response of solders and similar materials Zhang et al (2009). This model, as well as similar ones have been used to characterize the stress-strain response of metals Anand (1982;Brown et al (1989;M.…”

“…In addition to the use of the Power Law creep model, the Anand viscoplastic model was used to characterize the high temperature behavior of the Zr samples. The creep plastic strain rate in the Anand model Chen et al (2005;Zhang et al (2009) is given by ,…”

Development of lead-free solders in China during the past decade

“…针对含稀土元素 Ce 的 SnAgCu 焊点的可靠性已 有 较 为 成 熟 的 研 究 . 主 要 构 建 了 SnAgCuCe 的 Garofalo-Arrhenius model 模型 [115] 和 Anand 模型 [116] , 如(11)~(20)式所示. 借助本构模型, 借助有限元模拟, 研究 QFP256 器件 SnAgCuCe 焊点在55~125°C 热循 环条件下的应力-应变响应, 证实了 0.03%稀土元素 Ce 可以将 SnAgCu 焊点疲劳寿命提高超过 12% [117] .…”

Constitutive behavior and Anand model of novel lead-free solder Sn-Zn-Bi-In-P

“…Although there are nine different parameters in the Anand constitutive model, the determination procedure is not complicated and only the experimental data at several strain rates and several temperatures are needed. The standard procedures are outlined as follows [15,16,32,33]: a) Determination of the saturation stress from the stress-strain tests, i.e. stress-strain data groups at constant strain rates and different temperatures.…”