Abstract: Printed circuit boards, cards and chip carriers are fabricated by treating an already circuitized substrate with a swelling agent, then treating the circuitized substrate with a composition containing an alkaline permanganate, a chromate and/or chlorite and then applying a metal layer to coat the circuitized portion of the substrate.

Abstract: Printed circuit boards, cards and chip carriers are fabricated by treating an already circuitized substrate with a swelling agent, then treating the circuitized substrate with a composition containing an alkaline permanganate, a chromate and/or chlorite and then applying a metal layer to coat the circuitized portion of the substrate.

Abstract: Printed circuit boards, cards and chip carriers are fabricated by treating an already circuitized substrate with a swelling agent, then treating the circuitized substrate with a composition containing an alkaline permanganate, a chromate and/or chlorite and then applying a metal layer to coat the circuitized portion of the substrate.

Abstract: A technique for polishing an exposed surface of metal on a substrate to remove defects from mechanical working of metals, such as burrs and pigtails resulting from drilling, and defects from plating, such as nodules and depressions, is provided. The substrate has an exposed metal surface such as copper thereon which is to be treated to remove defects. A planarizing or polishing head, preferably a rotating roller, is provided which is continuously rotating with respect to the substrate, with the head in contact with the metal surface on the substrate. A chemical etchant, essentially free of abrasive material, is continuously supplied to the interface between the metal surface and the head. The treating and polishing continues until the defects have been removed or reduced to an acceptable value. In some instances where significant height reduction is required, thus requiring significant metal removal, several passes of the substrate may be required or a device with multiple heads may be used.

Abstract: Electrodepositing a metallurgy such as gold on to printed circuit board features. The methods include electrolessly depositing a copper layer over the surface of the printed circuit board. This is followed by applying a layer of photoresist atop the electroless copper, and exposing and developing the photoresist to uncover areas to be etched, leaving behind the specific features to be plated. By this expedient the remaining copper forms a commoning layer. The remaining photoresist is stripped to uncover the copper commoning layer, and a second layer of photoresist is applied atop the partially etched copper layer. This layer of photoresist is exposed and developed to uncover the features to be plated. These features are then plated with the metallurgy of choice. The photoresist is then stripped off and the electroless copper layer can remain if needed for further processing or be microetched off without harming copper traces that may exist below the electroless copper layer.