Abstract: An improved plating method in which non-plated vias or through holes are temporarily metalized for use as busses during selective noble metal plating and subsequently de-metalized to prevent shorting together of the nobly plated features.

Abstract: In a printed circuit board manufacturing process, a resist stripping solution blending organic amines with water is used for stripping the photoresist completely from the board. An apparatus for controlling this resist stripping solution comprises a toroidal conductivity controller for measuring the solution conductivity, which correlates to solution concentration. This same apparatus is equipped with a resist stripping solution discharge device for discharging the resist stripping solution and water replenishing device for replenishing water by detecting the liquid level of the resist stripping solution by a liquid level gauge. As the water is replenished, the solution conductivity is lowered; thereby activating the toroidal conductivity controller to add concentrated resist stripping chemistry proportionally to the deviation from the conductivity controller set point. This same apparatus is equipped with a measuring device for measuring the total consumed organic amine reactants.

Abstract: Mechanical forming apparatus and method for manufacturing planar contact projections for a flexible circuit is disclosed. A forming die includes a punch assembly configured for mating with a die plate. The punch assembly comprises a pin plate coupled to a punch plate and configured to hold adjusting pins and forming punches, respectively. Each forming punch has a tail with a contoured tip that conforms to the geometry of a desired contact projection. The die plate has a plurality of cavities configured and dimensioned for receiving the tail tips of the punches. In operation, the punch assembly and die plate are placed in a die set and installed in an open position in a punch press with a flexible circuit positioned therein. When activated, the press closes the die set, causing the punch tails to push against the flexible circuit, while circuit material flows into the die plate cavities. As the cavities fill, any excess material is compressed into peripheral areas of the die plate surrounding the cavities.