Probe-on-substrate

摘要

Probes are directly patterned on a test substrate, thereby eliminating a need for an interposer. Probe contact structures are formed as a two-level structure having a greater lateral dimension for a lower level portion than for an upper level portion. First cavities are formed in a masking layer applied to a test substrate, filling the cavities with a conductive material, and planarizing the top surfaces of the conductive material portions to form lower level portions. Another masking layer is applied over the lower level portions and patterned to define second cavities having a smaller lateral dimension that the lower level portions. The second cavities are filled with at least one conductive material to form upper level portions of the probe contact structures. The upper level portion of each probe contact structure can be employed to penetrate a surface oxide of solder balls.

主权项

1. A probing apparatus comprising a plurality of conductive probes located on a top surface of a substrate, wherein each conductive probe within said plurality of conductive probes comprises:
a first columnar conductive structure having a same first horizontal cross-sectional area between a topmost surface of said first columnar conductive structure and a bottommost surface of said first columnar conductive structure; and a second columnar conductive structure located on said topmost surface of said first columnar conductive structure and having a same second horizontal cross-sectional area between a topmost surface of said second columnar conductive structure and a bottommost surface of said second columnar conductive structure,wherein each conductive probe within said plurality of conductive probes further comprises a conductive coating layer comprising at least one conductive material,and wherein said conductive coating layer contacts all surfaces of said first columnar conductive structure that are not in contact with said substrate or said second columnar conductive structure, and contacts all surfaces of said second columnar conductive structure that are not in contact with said first columnar conductive structure.