Satyanarayan, S.Prabhu, K.2026-02-052013Journal of Electronic Materials, 2013, 42, 8, pp. 2696-27073615235https://doi.org/10.1007/s11664-013-2619-7https://idr.nitk.ac.in/handle/123456789/26747The effect of surface roughness of copper substrate on the reactive wetting of Sn-Ag-Cu solder alloys and morphology of intermetallic compounds (IMCs) was investigated. The spreading behavior of solder alloys on smooth and rough Cu substrates was categorized into capillary, diffusion/reaction, and contact angle stabilization zones. The increase in substrate surface roughness improved the wetting of solder alloys, being attributed to the presence of thick Cu <inf>3</inf>Sn IMC at the interface. The morphology of IMCs transformed from long needle shaped to short protruded type with an increase in the substrate surface roughness for the Sn-0.3Ag-0.7Cu and Sn-3Ag-0.5Cu solder alloys. However, for the Sn-2.5Ag-0.5Cu solder alloy the needle-shaped IMCs transformed to the completely scallop type with increase in the substrate surface roughness. The effect of Ag content on wetting behavior was not significant. © 2013 TMS.Angle stabilizationCopper substratesIMCLead free soldersReactive wettingSn-Ag-Cu solder alloysSubstrate surfaceWetting behaviorAlloysContact angleCopperCopper alloysCopper compoundsMorphologyNeedlesSilverSilver alloysSoldering alloysSubstratesSurface roughnessTin alloysWettingTin