Patent ID: 6893799
Filing Date: 2005-05-17
Classification: H01L

Abstract:
1. A method to form a solder bump on an electronic package comprising the steps of; providing an electronic package containing a plurality of electrically conductive pads; depositing at least one blanket metal layer onto said electronic package; depositing a photo-resist material onto said at least one blanket metal layer; exposing said photo-resist material on said at leas one blanket metal layer to form a photo-resist mask; electro-depositing a layer of solder-wettable metal into the exposed regions of the blanket metal layer removing said photo-resist mask; selectively etching said at least on blanket metal layer outside the electro-deposited solder-wettable metal using said solder-wettable metal as an etch mask, thereby forming solder wettable metal pads; depositing bulk solder bumps onto said solder wettable metal pads; and reflowing said bulk solder bumps.