E.i. Dupont De Nemours and Company

Grant A Beske

Abraham B Cohen

John W Lott

Sam Andreades

Roger O Uhler

Electrically conductive through-holes in a substrate are prepared by (a) laminating a film based plastic photosensitive toner-receptive stratum to at least one surface of the substrate; (b) applying a pressure differential across the stratum covering the substrate holes, the outside pressure exceeding that inside the holes; in either order (c) removing at least one film base or (d) exposing the photosensitive stratum imagewise, (e) adhering metal or catalytic particles to hole walls and image areas, (f) optionally hardening or curing the particulate areas and (g) providing an electrically conductive printed circuit and through-holes, e.g., by plating metal electrolessly, soldering or conjoining the metallized or catalyzed areas.

Use of photosensitive stratum to create through-hole connections in

Preparation of an electrically conductive pattern by adhering a prolonged tack toner which is activated by heating to the toner-receptive image areas of an inert substrate, the temperature is reduced and to the activated toner is applied a prolonged tack toner having conductive metal particles and glass frit as components; optionally the steps of heating, temperature reduction and toner application are repeated at least one time, and then the toned image is burned and fired. An electrically conductive pattern is obtained which is useful, for example, as an electric circuit. The process is also useful in the application of resistor and dielectric materials.

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Princeton Junction, NJ, United States of America

Grant A Beske