Mechanical Behavior of Eutectic Sn-Ag and Sn-Zn Solders

Abstract

Eutectic Sn-Ag and Sn-Zn solders are currently being investigated as the basis for replacement of Sn-Pb solders. Some mechanical properties of these solder systems - fatigue, tensile, stress relaxation and creep are presented here along with some damage feature observations for eutectic Sn-Ag solder. Semi-empirical modeling, constitutive modeling and numerical simulation based on damage models have been carried out for lifetime prediction. Preliminary agreement of this numerical simulation with experimental results appears encouraging, but the models need further refinement.

Effect of indium content and rapid solidification on microhardness and micro‐creep of Sn‐Zn eutectic lead free solder alloy

“…The addition of indium to the Sn-Zn binary system improves the wetting characteristics of the alloy and lowers the melting temperature [4]. Creep, stress relaxation, and plastic deformation in Sn-Ag and Sn-Zn eutectic solders has been studied by H.Mavoori et al [5]. They were studied two eutectic lead-free solders are investigated for their creep and stress relaxation behavior.…”

Control of Electrical and Thermal Properties by 8 vol% Al₂O₃ Distribution States in Zn–50Sn for AC-Low Voltage Fuses

“…(3), (4), (6), (7), (8), (9) as the function of the temperature. The μ e , , c p and μ measured at 293 and 470 K for both Zn50Sn8 vol%Al 2 O 3 alloys, are listed in Table 1.…”

“…3,4,7) In contrast, since an eutectic point (471 K) of Sn Zn system alloys is similar to that (456 K) of the practically used Sn40Pb, it has been also considered by other investigators as a candidate alloy system for a lead-free solder material. 8,9) The SnZn eutectic system which is basically classified as an anomalous eutectic alloy has a broken-lamellar type eutectic structure. 10) The faceting lamellas are Zn and the non-faceting phase is the Sn solid solution.…”

Material issues in electronic interconnects and packaging

“…Several studies on solders are being carried out on bulk solder samples under accelerated thermal shock conditions to understand their thermomechanical fatigue behavior, and to arrive at reliability predictions. 11,12 However, in a realistic solder joint, the solder between the lead of the electrical component and the metallic substrate is under severe mechanical constraints. The mechanical behavior of the solder present in the joint under the stresses that develop due to CTE mismatches is controlled by the mechanical behavior of the constituents in the electronic package, and the intermetallic layers.…”