A plurality of contact elements, such as contact bumps or free-standing
spring contacts including both monolithic and composite interconnection
elements, are mounted to relatively small tile substrates which, in turn,
are mounted and connected to a relatively large electronic component
substrate, thereby populating the electronic component with a plurality of
contact elements while avoiding the necessity of yielding the contact
elements directly upon the electronic component. The relatively large
electronic component is suitably a space transformer component of a probe
card assembly. In this manner, pressure connections can be made to an
entire semiconductor wafer, at once, to provide for wafer-level burn-in,
and the like. Solder balls, z-axis conductive adhesive, or compliant
connections are suitably employed for making electrical connections
between the tile substrates and the electronic component. Multiple die
sites on a semiconductor wafer are readily probed using the disclosed
techniques, and the tiles can be arranged to optimize probing of an entire
wafer. Composite interconnection elements having a relatively soft core
overcoated by a relatively hard shell, as the resilient contact structures
are described. Techniques for maintaining a prescribed x-y and z-axis
alignment of the tiles to the relatively large substrate are disclosed.
