Numerical computation of wetting angles of Sn–(3−x)Ag–0.5Cu−x(Bi,In) quaternary Pb-free solder alloy systems on Cu substrate

Abstract

This paper was aimed to study of the wetting angle ([Formula: see text]) of Sn–Ag–Cu, Sn–([Formula: see text])Ag–0.5Cu–([Formula: see text])Bi and Sn–([Formula: see text])Ag–0.5Cu–([Formula: see text])In ([Formula: see text], 1 and 2 in wt.%) Pb-free solder alloy systems at various temperatures (250, 280 and 310∘C) on Cu substrate in Ar atmosphere. The new Sn–([Formula: see text])Ag–0.5Cu–xBi and Sn–([Formula: see text])Ag–0.5Cu[Formula: see text]([Formula: see text]) In systems, low Ag content quaternary Pb-free solder alloys, were produced by adding 0.5%, 1% and 2% Bi and In separately to the near-eutectic Sn-3[Formula: see text]wt.%Ag–0.5[Formula: see text]wt.%Cu (SAC305) alloy. The wetting angles of new alloys, Sn[Formula: see text]2.5[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt.%Cu[Formula: see text]0.5[Formula: see text]wt.%Bi (SAC-0.5Bi), Sn[Formula: see text]2[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt.%Cu[Formula: see text]1[Formula: see text]wt.%Bi(SAC-1Bi), Sn[Formula: see text]1[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt.%Cu[Formula: see text]2[Formula: see text]wt.%Bi(SAC-2Bi), Sn[Formula: see text]2.5[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt.%Cu[Formula: see text]0.5[Formula: see text]wt.%In (SAC-0.5In), Sn[Formula: see text]2[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt.%Cu[Formula: see text]1[Formula: see text]wt.%In (SAC-1In) and Sn[Formula: see text]1[Formula: see text]wt.%Ag[Formula: see text]0.5[Formula: see text]wt%.Cu[Formula: see text]2[Formula: see text]wt.%In (SAC-2In) were measured by sessile drop method. Experimental results showed that additions of Bi and In separately to SAC305 resulted in a continuous decrease in the [Formula: see text] up to 1[Formula: see text]wt.% above which the [Formula: see text] value was increased and it is appeared that a correlation among the [Formula: see text], alloys compositions and the test temperatures exists which recommended an empirical model to estimate the [Formula: see text] at a given Bi and In content and temperature for a given alloy systems. The numerical model estimates the [Formula: see text] understandably well with the present work.