Patent ID: 6179200
Filing Date: 2001-01-30
Classification: B23K,H01L,H05K

Abstract:
A method for forming solder balls of improved height on an electronic substrate comprising the steps of:providing an electronic substrate having a multiplicity of conductive pads on a top surface,patterning a photo mask overlying said substrate for providing a multiplicity of openings exposing said multiplicity of conductive pads,filling said multiplicity of openings with a solder material,removing said photo mask from said substrate forming said multiplicity of upwardly standing solder bumps on said top surface,turning said electronic substrate upside down such that said multiplicity of upwardly standing solder bumps point downwardly, andheating said multiplicity of solder bumps at a temperature at least the reflow temperature of said solder material for a sufficient length of time such that said solder bumps are reflown into solder balls having improved height caused by gravity when compared to solder balls that are not reflown in an upside down position.