Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Werner Budweiser

Kenneth Kaskoun

Erik Jung

A substrate ( ) includes a conductive layer ( ) which is non-wettable by solder. A solder receiving stud ( ) is formed on the conductive layer, preferably by plating. If used for transferring solder, a solder bump ( ) is selectively formed on the solder receiving stud since the surrounding conductive layer is not wettable by the solder. A receiving substrate, such as a semiconductor device ( ), is aligned with the substrate. The solder bump is heated to a liquidus state and the solder bump makes physical contact with a solder accepting stud ( ) of the receiving substrate. Because the area of the solder accepting stud is larger than the area of the corresponding stud on the transfer substrate, the majority of the solder will transfer to the receiving substrate upon separation. Alternatively, the device could itself already have bumps formed thereon, in which case an unbumped substrate is used to test the device, and solder remains on the device upon separation.

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Berlin, Germany

Werner Budweiser