Abstract: A PWB or multilayer board with circuit traces is treated by a process that serves to reduce the incident of failure of the board. The process includes the steps of applying a thin commoning layer of copper onto a catalyzed surface of the board substrate and the circuit lines. A photoresist is then applied over the commoning layer after which the photoresist is removed only from the commoning material over the circuit lines. A thin layer of a more noble metal, such as nickel, is electrodeposited over the exposed conductive layer. This is followed by a gold layer electrodeposited over the nickel in close registry therewith. The process provides the traces with a conforming nickel/gold layer that extends down the side of the traces. This reduces the tendency of a subsequent copper etch step from undercutting the nickel/gold, thereby causing slivers that could cause short circuiting between adjacent circuit patterns.

Abstract: A PWB or multilayer board with circuit traces is treated by a process that serves to reduce the incident of failure of the board. The process includes the steps of applying a thin commoning layer of copper onto a catalyzed surface of the board substrate and the circuit lines. A photoresist is then applied over the commoning layer after which the photoresist is removed only from the commoning material over the circuit lines. A thin layer of a more noble metal, such as nickel, is electrodeposited over the exposed conductive layer. This is followed by a gold layer electrodeposited over the nickel in close registry therewith. The process provides the traces with a conforming nickel/gold layer that extends down the side of the traces. This reduces the tendency of a subsequent copper etch step from undercutting the nickel/gold, thereby causing slivers that could cause short circuiting between adjacent circuit patterns.

Abstract: A PWB or multilayer board with circuit traces is treated by a process that serves to reduce the incident of failure of the board. The process includes the steps of applying a thin commoning layer of copper onto a catalyzed surface of the board substrate and the circuit lines. A photoresist is then applied over the commoning layer after which the photoresist is removed only from the commoning material over the circuit lines. A thin layer of a more noble metal, such as nickel, is electrodeposited over the exposed conductive layer. This is followed by a gold layer electrodeposited over the nickel in close registry therewith. The process provides the traces with a conforming nickel/gold layer that extends down the side of the traces. This reduces the tendency of a subsequent copper etch step from undercutting the nickel/gold, thereby causing slivers that could cause short circuiting between adjacent circuit patterns.

Abstract: A method for cleaning a copper-INVAR-copper laminate in an acid solution without inducing a galvanic etching of the INVAR. An initial step of the method forms a circuit element that includes a power supply, the laminate electrically coupled to a negative terminal of the power supply, and a conductive anode electrically coupled to a positive terminal of the power supply. The conductive anode may include a conductive material, such as titanium, that is preferably inert to an acid solution into which the laminate will be subsequently immersed. After turning on the power supply to a voltage between about 1 volts and about 10 volts, the laminate and conductive anode are immersed in the acid solution, so as to form a closed circuit with a voltage bias across acid copper-INVAR-copper interfaces. The voltage bias prevents galvanic action from occurring and therefore protects against galvanic etching of the INVAR.

Abstract: An electroplating apparatus provides high current electrical connections in a small area to a workpiece. The contact area may use a dendrite surface to improve the connection. An insulative gasket prevents electroplating fluids from entering the region about the contact area. A heavy core laminated within a supporting structure provides uniform current distribution of high electrical currents to the dendrite covered contact areas.

Abstract: The present invention provides a novel method for forming uniform dendrites, on circuit features that does not result in large, elongated dendrites along the edges of the circuit features. The method comprises the following steps: providing a substrate having circuitry disposed thereon; applying a photoresist to the substrate at a thickness which is preferably about the height of the intended dendrite height; imaging the photoresist to expose all or a portion of the top surface of the circuitry; forming the dendrites; and removing the photoresist. The photoresist which is employed to control the dendrite height is applied so that the photoresist either: abuts the edge of the circuitry leaving the top surface of the circuitry exposed; or abuts the edge of the circuitry and extend over the top edge of the circuitry so that a portion of the top surface of the circuitry is exposed; or does not touch the circuitry nor an area surrounding the base of the circuitry.

Abstract: The present invention provides uniform dendrites, on circuit features instead of large, elongated dendrites along the edges of the circuit features. The dendrites are formed by a method comprising the following steps: providing a substrate having circuitry disposed thereon; applying a photoresist to the substrate at a thickness which is preferably about the height of the intended dendrite height; imaging the photoresist to expose all or a portion of the top surface of the circuitry; forming the dendrites; and removing the photoresist. The photoresist which is employed to control the dendrite height is applied so that the photoresist either: abuts the edge of the circuitry leaving the top surface of the circuitry exposed; or abuts the edge of the circuitry and extend over the top edge of the circuitry so that a portion of the top surface of the circuitry is exposed; or does not touch the circuitry nor an area surrounding the base of the circuitry.