Patent ID: 7666780

Claim:
A method for forming solder bumps on an electronic substrate surface comprising the steps of: providing a solder transfer mold having a plurality of solder mold openings in an array, which mold openings are filled with solder; providing an electronic substrate containing pads in an array to which pads the solder in the mold is to be transferred, the mold array corresponding to the substrate pad array and the substrate having an inactive area having one or more inactive pads; depositing a material around the periphery of the one or more inactive pads, which material reacts with molten solder; positioning the solder containing openings of the mold proximate the surface or pads of the electronic substrate to which the solder is to be transferred; providing a seal around the mold and the electronic substrate and forming a chamber; heating the chamber to an elevated temperature to liquefy the solder; transferring the solder from the mold openings to the corresponding pad array on the electronic substrate surface by bringing the solder mold and electronic substrate into transfer contact and forming an empty mold; removing the seal from the around the mold and removing the empty mold from the electronic substrate leaving the electronic substrate with the solder from the mold openings on the pad surfaces thereof; and examining the one or more inactive pads of the electronic substrate and measuring the material which reacted with the molten solder to determine if any alignment off-set resulted from the solder transfer.