Abstract: A novel printed circuit laminate product and process are provided for use in connection with a printed circuit board. The laminate is composed of a polyimide support stratum, a copper electrical conductor stratum, and an intermediate adhesive stratum. In one form, the opposite faces of the laminate are separately etched to provide different circuit related features and the laminate as an entirety has through holes, which have particular cross sectional geometry and which are produced by particular process steps. In another form, the copper stratum is laminated to the adhesive face of the adhesive and support strata and is etched after through holes have been drilled in the adhesive and support strata.

Abstract: Printed circuits are produced by an additive technique wherein a metal-loaded resinous ink is first printed on the board, the circuit next being covered with a conductive metal powder while the ink is still wet. The powder is then pressed into the ink and the circuit cured. Next, a solder stratum is alloyed with the powder as by a solder paste printed over the circuit and the board heated to cause the solder to alloy with the ink and powder substrates. A solder resist may then be applied selectively over the circuit and multiple layers of circuits may be built up on the board. The conductive ink is an epoxy resin loaded with a metallic powder, preferably copper, with a catalyst added to the ink. The solder paste is a lead-tin alloy containing antimony suspended in a binder and a flux.The apparatus employed to carry out the procedure includes silk screens and a roller arrangement for pressing the metallic powder into the ink. The press includes a plurality of progressively harder rollers.

Abstract: Printed circuits are produced by an additive technique wherein a metal-loaded resinous ink is first printed on the board, the circuit next being covered with a conductive metal powder while the ink is still wet. The powder is then pressed into the ink and the circuit cured. Next, a solder stratum is alloyed with the powder as by a solder paste printed over the circuit and the board heated to cause the solder to alloy with the ink and powder substrates. A solder resist may then be applied selectively over the circuit and multiple layers of circuits may be built up on the board. The conductive ink is an epoxy resin loaded with a metallic powder, preferably copper, with a catalyst added to the ink. The solder paste is a lead-tin alloy containing antimony suspended in a binder and a flux.The apparatus employed to carry out the procedure includes silk screens and a roller arrangement for pressing the metallic powder into the ink. The press includes a plurality of progressively harder rollers.