Abstract: A printed circuit including a dielectric substrate and a conductive trace attached to a surface of the dielectric substrate. The trace includes a base layer and a coverplate layer on a portion of the base layer. The coverplate layer defines a coverplate edge on the base layer. A protective layer is formed on a portion of the coverplate layer. The protective layer extends beyond the coverplate edge onto at least a portion of the base layer of the trace. A key aspect of the present invention is that the protective layer overlaps the coverplate edge of each trace to reduce the potential for corrosion of the base layer at the coverplate edge.

Abstract: The method and apparatus of the present invention permits the automated deposition of heated solder onto a plurality of conductive pads which are disposed in one or more linear arrays on a circuit board or other planar member. A robotically controlled arm is utilized to mount a solder nozzle and selectively manipulate the solder nozzle over the circuit board. The solder nozzle is first manipulated to a selected point offset in a known direction and distance from a first conductive pad by means of a data set which specifies the centroid and footprint for a selected group of conductive pads. After feeding solder into the solder nozzle, aligning the solder nozzle at a desired angle parallel to a linear array of conductive pads and lowering the solder nozzle until a solder droplet contacts the circuit board, the solder nozzle is manipulated at a substantially constant velocity toward the first conductive pad and thereafter along a selected line which tracks the linear array of conductive pads.

Abstract: A nozzle assembly is shown for depositing solder onto a series of conductive surfaces such as the mounting pads of a surface mount integrated circuit board. The nozzle assembly includes a nozzle head which has an interior bore for receiving an elongate heat source. The nozzle head also includes an orifice for receiving solid solder fed within the interior bore to contact the elongate heat source. The interior bore terminates in a solder reservoir for molten solder which is fed within the inteiror bore to contact the elongate heat source. The molten solder is dispensed through a tip opening to deposit uniform amounts of solder on each pad. A source of bleed gas is supplied to the interior of the assembly to protect the component parts and excluse oxygen from the interior of the assembly. A cover gas is also supplied to the solder site to reduce oxidation of the moltent solder and reduce the amount of flux required.