Fabrication of leads on semiconductor connection components

DETAILED DESCRIPTION The present invention addresses these needs.
One aspect of the present invention provides methods for making a connection component for a microelectronic element.
Methods according to this aspect of the invention desirably include the steps of providing a substantially continuous layer of a first metal, typically an economical, etchable base metal such as copper or a copper alloy, and selectively depositing a plurality of conductive portions of a second metal on the first metal layer.
The second metal may be deposited in elongated strips, and may be a malleable precious metal such as a gold alloy or, preferably, substantially pure gold.
The methods according to this aspect of the invention further include the step of providing a dielectric support juxtaposed with the first metal layer and selectively removing the first metal after selectively depositing the second metal conductive portions or strips.
The selective removal forms a plurality of conductive portions from the first metal.
The conductive portions of the first metal formed during the selective removal step are contiguous with the conductive portions of the second metal.
The conductive portions of the second metal and first metal thus form a plurality of composite leads, each such composite lead including conductive portions of the first and second metals connected to one another.
Thus, the conductive portions of the first metal formed by the selective removal step may include a plurality of elongated strips of the first metal, and the depositing and removing steps may be performed so that at least some of the composite leads include strips of the first and second metal connected in series with one another.
The process may further include the step of providing gaps in the dielectric support registered with the strips of the second metal so that the strips of the second metal extend across the gaps.
Thus, the strips of the second metal may constitute the connection sections of leads in an arrangement as disclosed in the `036 Publication, whereas the sections formed from the first metal may constitute the remainder of the leads