Effect of Al Addition on Microstructure, IMCs and Wettability of Sn-2Ag-0.5Cu-lIn-xAl Lead Free Solder Alloy

Addition of Al in Microstructures

Abstract

The present study investigated the effect of adding a small amount of Al on the wettability, microstructure, formation of intermetallic compounds (IMC'S) and melting temperature of SAC205-1In lead free solder alloys, the quinary lead free solder alloys SAC205-1In-(x)AL with (x = 0.3 wt.%, 0.5 wt.%, 0.7 wt%, 0.8 wt%, 0.9 wt%) were produced. The X-ray diffraction results (XRD) showed the formation of new IMCs into the alloy at the SAC205-1In-xAl/Cu interface; intermetallic compounds of Cu3Sn, Cu6Sn5, Ag3Sn, Ag3Al, Ag2Al, Al2Cu and Cu-Al were observed. According to the scanning electronic microscope (SEM) analysis, the intermetallic components generated at the interface of each lead free solder alloy grew increasingly apparent as the temperature value increased. The contact angles of the Pb free solder alloys on the copper (Cu) substrate were measured using the sessile drop technique at specified temperatures (275 °C, 300 °C and 325 °C). The wetting tests' findings indicate that adding aluminum (Al) improves the Sn-2Ag-0.5Cu-1In solder's wetting characteristics. According to the study, SAC205-1In- 0.3Al showed the best wettability among all solder alloys produced on a Cu substrate at a temperature of 325°C. By optimizing Sn-Al in the range of 0.3 wt.%, 0.5 wt.%, 0.7 wt.%, 0.8 wt.% and 0.9 wt. % and also possible to reduce the production cost of solder alloys.