Effect of Wetting Characteristics of Dimpled Micro-textured Substrate on the Spreading Area of Sn–0.7Cu Solder Alloy

This study aimed to investigate the effect of wetting characteristics of a dimpled micro-textured copper substrate on the spreading area of the Sn–0.7Cu solder alloy. A laser surface texturing (LST) technique was used to fabricate dimpled micro-textured on the copper substrate. Three samples were fabricated by varying the dimple spacing on the copper substrate such as 100, 140, and 180 µm. A 3D measuring laser microscope was used to study the surface roughness. The copper substrates’ water contact angle measurement and surface roughness were studied for their wetting characteristics. In order to study the effect of wetting characteristics of the dimpled micro-textured copper substrate, spreading area measurement was conducted. The result showed that dimpled micro-textured introduces higher surface roughness and contact angle, increasing the hydrophobicity. Consequently, this reduces the spreading area of Sn–0.7Cu solder alloy.