Patent ID: 7008868
Filing Date: 2006-03-07
Classification: H01L

Abstract:
1. A method of making a bumped wafer, the method comprising: providing a non-passivated die; alternatingly sputtering a first titanium layer, a first copper layer, a second titanium layer and a second copper layer onto the die; depositing photo resist material onto the second copper layer; etching isolation areas thereby removing the photo resist material, the second copper layer, the second titanium layer and the first copper layer at the isolation areas; depositing photo resist material to define bump locations; etching at bump locations thereby removing portions of the second copper layer and the second titanium layer at the bump locations; depositing under-bump material at the bump locations; depositing solder on the under-bump material; removing the photo resist material; etching the second titanium layer at the isolation locations; etching the second copper layer; and reflowing the solder.