Using　the　interactive　software,　this　study　was　mainly　focused　on　developing　a　3-D　joint　shape　after　the　as-reflowed　soldering　which　is　the　one　of　chief　factors　affecting　the　reliability.　From　the　results,　the　soldering　process　can　be　simulated　and　observed　directly.　By　changing　the　various　conditions　and　constraints,　such　as　surface　tension,　wetting　angle　and　specific　gravity,　it　makes　a　comparison　between　the　simulated　result　and　the　experimental　one.　The　simulated　parameters　are　based　on　those　of　the　traditional　eutectic　Sn-Pb　solder.　After　slicing　and　comparing　the　different　profiles　of　the　simulated　shape,　the　3-D　simulated　geometry　fits　well　with　the　experimental　one.