General Dynamics Corp., Pomona Division

General Dynamics Corporation, Air Defense Systems Division

Marvin R Johnson

William P Dugan

A method for manufacturing a probe test structure for microcircuits utilizes a multiple coating method in conjunction with a novel double-cell electroplating apparatus having a relatively high-resistance ion path between the cells. Photoresist is applied to both sides of a copper foil, copper posts are electroformed onto selected areas of one side of the foil through image hole patterns, the remaining photoresist is stripped away, polyimide prepreg is laminated to the post side of the foil, the copper posts are exposed by sanding, photoresist is reapplied to both sides of the sanded remainder, additional copper is electroformed on each post through image hole patterns in the post side of the photoresist, the foil on the side opposite the posts is chemically milled to provide leads integral with each post using appropriate masking techniques and, finally, all of the remaining photoresist is removed to leave the desired test probe set. In a second embodiment, nickel plating is added over the copper to achieve selective etching, permitting processing of both sides of the copper foil simultaneously.

Electroformed chemically milled probes for chip testing

A method for manufacturing a probe test structure for microcircuits utilizes a multiple coating method in conjunction with a novel double-cell electroplating apparatus having a relatively high-resistance ion path between the cells. Photoresist is applied to both sides of a copper foil, copper posts are electroformed onto selected areas of one side of the foil through image hole patterns, the remaining photoresist is stripped away, polyimide prepreg is laminated to the post side of the foil, the copper posts are exposed by sanding, photoresist is reapplied to both sides of the sanded remainder, additional copper is electroformed on each post through image hole patterns in the post side of the photoresist, the foil on the side opposite the posts is chemically milled to provide leads integral with each post using appropriate masking techniques and, finally, all of the remaining photoresist is removed to leave the desired test probe set. In a second embodiment, nickel plating is added over the copper to acheive selective etching, permitting processing of both sides of the copper foil simultaneously.

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Mira Loma, CA, United States of America

Marvin R Johnson