Abstract: A system of disassemblable contact junctions for prefabricated conductor paths, such as may be provided on printing wiring boards, flexible printed cables or the like, Each contact junction includes a pressure point contact attached to an associated conductor path. Both the pressure point contact and the opposed conductor path are coated with solder or equivalent. Rigid blocks on opposite sides of the two sets of circuit conductors with an interspersed pad of compliant material, such as rubber, hold the assembly together under substantial pressure. Each of the pressure point contacts is formed with a ridge along the contacting face which, under the pressure developed by the assembly, penetrates through the oxide surfaces of the contacting solder layers, breaking the oxide surfaces and forming a gas tight electrical connection provided by the cold flow of the solder.

Abstract: The present invention is directed to a method of preparing a substrate to improve the adherence of a metallic coating to the substrate and the product thereof. More particularly, a method of manufactiring a molded circuit board and unique circuit board produced thereby, is disclosed. A molding compound, such as an epoxy resin is blended with a plating additive, such as calcium carbonate that is relatively inert to the molding compound. The blended mix can then be molded into a desired shape which, for a printed circuit board, can be a relatively flat plate configuration with a recessed groove and hole formation pattern. The high relief areas of the circuit board can be masked with a protective material. The plating additive can then be chemically etched from the grooved recessed area and holes, for example, by a hydrochloric acid bath. Appropriate catalyst and accelerators can be applied to the recessed groove pattern before the protective mask material is removed.

Abstract: Method of forming an electrode for imprinting or imaging a circuit board mold face includes covering a graphite substrate with a photoresist material. The photoresist material is appropriately exposed to develop a desired pattern. The unpolymerized photoresist is removed from the graphite substrate to leave the desired pattern of an exposed graphite surface. The graphite substrate is then impacted by a dry air blast of glass beads having a size in the range of approximately 200 to 325 mesh. The glass beads will remove a desired amount of graphite to thereby cut the desired pattern into the substrate but will not remove the photoresist or affect the substrate beneath the polymerized photoresist. The polymerized photoresist is removed with materials that will not interfere with the subsequent machining process. The resultant cut graphite substrate can be utilized as a electrode in an electrical discharge machining process to form a desired pattern in a mold face.

Abstract: An improved bond between the metal and dielectric layers of metal-clad dielectric sheeting is obtained by use of a black-chromium treatment on the metal layer.