The Effect of Dipping Time to the Intermetallic Compound and Free Solder Thickness of Sn-Cu-Ni (SN100C) Lead-Free Solder Coating

Abstract

The effect of dipping time to the intermetallic compound and free solder thickness of Sn-Cu-Ni (SN100C) lead-free solder has been investigated. Dipping of copper strips in molten solder was carried out using GEN3 solderability test machine with 20 s, 60 s, 120 s, 180 s, and 240 s of dipping time. Scanning Electron Microscope (SEM) was used to observe the solder coating on the copper strips. Thickness of IMC, free solder and total solder coating was calculated. The influence of dipping time was established. The results indicated that longer dipping time produced high IMC thickness while the free solder thickness reduced with the growth of IMC. Solderability test was also conducted to know the wettability of SN100C coating for the lowest dipping time which had resulted in 1.571 s of wetting time and 4.066 mN of maximum force.