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AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsKuo-Wei Lin, James Chen, Eugene Chu, Alex Fahn, Chiou-Shian Peng, Gilbert Fane, Kenneth Lin
Estimating the term…
A method for removing a multiplicity of solder bodies connected to a semiconductor wafer through a copper wetting layer from the semiconductor wafer is disclosed. In the method, a semiconductor wafer that has on a top surface a multiplicity of solder bodies electrically connected to a multiplicity of bond pads through a multiplicity of copper wetting layers is first provided. When the multiplicity of solder bodies is found out of specification or must be removed for any other quality reasons, the semiconductor wafer is exposed to an etchant that has an etch rate toward the copper wetting layer at least 5 times the etch rate toward a metal that forms the multiplicity of bond pads. The semiconductor wafer may be removed from the etchant when the multiplicity of copper wetting layers is substantially dissolved such that the multiplicity of solder bodies is separated from the multiplicity of bond pads. The multiplicity of solder bodies may be either solder bumps or solder balls. The etchant may be a solution that contains Ce (NH4)2 (NO3)6 in a concentration range between about 3 wt. % and about 30 wt. % in water. Ultrasonic vibration may further be used to facilitate the dissolution of the copper wetting layers in the etchant.
A method for removing a multiplicity of solder bodies connected to a semiconductor wafer through a copper wetting layer from said wafer comprising the steps of:
A method for removing a multiplicity of solder bumps connected to a semiconductor wafer through a copper wetting layer from said wafer comprising the steps of:
A method for removing a multiplicity of solder balls connected to a semiconductor wafer through a copper wetting layer from said wafer comprising the steps of:
Dependencies are inferred from the claim text.