A Hybrid Method Combining Improved StochSim with SSA for Solving Systems with Multi-State Species

Interconnection elements for electronic components, exhibiting desirable mechanical characteristics (such as resiliency, for making pressure contacts) are formed by shaping an elongate element (core) of a soft material (such as gold) to have a springable shape (including cantilever beam, S-shape, U-shape), and overcoating the shaped elongate element with a hard material (such as nickel and its alloys), to impart a desired spring (resilient) characteristic to the resulting composite interconnection element. A final overcoat of a material having superior electrical qualities (e.g., electrical conductivity and/or solderability) may be applied to the composite interconnection element. The elongate element may be formed from a wire, or from a sheet (e.g., metal foil). The resulting interconnection elements may be mounted to a variety of electronic components, including directly to semiconductor dies and wafers (in which case the overcoat material anchors the composite interconnection element to a terminal (or the like) on the electronic component), may be mounted to support substrates for use as interposers and may be mounted to substrates for use as probe cards or probe card inserts. In one embodiment, a hybrid composite interconnection element is formed by mounting a core to an end of an flat elongate element formed from a sheet, and overcoating at least the core, the flat elongate element providing a "floating" support for the overcoated core, capable of absorbing non-planarities (tolerances) of an electronic component. Methods of fabricating interconnection elements on sacrificial substrates are described. Methods of fabricating tip structures and contact tips at the end of interconnection elements are described.