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

摘要

This paper was aimed to study of the wetting angle (circle minus) of Sn-Ag-Cu, Sn-(3-x)Ag-0.5Cu-(x)Bi and Sn-(3-x)Ag-0.5Cu-(x)In (x = 0:5, 1 and 2 in wt.%) Pb-free solder alloy systems at various temperatures (250, 280 and 310 degrees C) on Cu substrate in Ar atmosphere. The new Sn-(3-x)Ag0.5Cu-xBi and Sn-(3-x)Ag-0.5Cu-(x) 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 Sn3wt.%Ag-0.5wt.%Cu (SAC305) alloy. The wetting angles of new alloys, Sn-2.5wt.%Ag-0.5wt. %Cu-0.5wt.%Bi (SAC-0.5Bi), Sn-2wt.%Ag-0.5wt.%Cu-1wt.%Bi(SAC-1Bi), Sn-1wt.% Ag-0.5 wt.%Cu-2 wt.%Bi(SAC-2Bi), Sn-2.5 wt.%Ag-0.5 wt.%Cu-0.5 wt.%In (SAC-0.5In), Sn-2 wt.%Ag-0.5 wt.%Cu-1 wt.%In (SAC-1In) and Sn-1 wt.%Ag-0.5 wt%.Cu-2 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 circle minus up to 1 wt.% above which the-value was increased and it is appeared that a correlation among the circle minus, alloys compositions and the test temperatures exists which recommended an empirical model to estimate the circle minus at a given Bi and In content and temperature for a given alloy systems. The numerical model estimates the-understandably well with the present work.