PLATING RACK FOR HOLDING PRINTED WIRING BOARDS (PWB) IN PLATING TANKS
Original Publication Date: 1986-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
In the past, plating racks have been made of metal and covered with a rubber material to prevent them from becoming plated while immersed in a plating bath solution for plating printed circuit boards. Such racks are used for supporting, e,g. electrographic head panels comprising printed wiring boards (PWB), for immersion into a plating bath solution. These frames must be made of conductive material, usually stainless steel, and be in electrical contact with the panels to be plated to function as a cathode in the bath solution. The problem is that the rubber coating deteriorates quickly and, soon, plating deposits build up on the exposed metal surfaces of the rack, This is not only undesirable from the standpoint of waste of plating material but also increases the total surface area actually plated in the bath thereby affecting the plating rate of' the bath and the overall uniformity of desired plating thickness on the panel Thus, there must be a way of stopping this deterioration so as not to effect the plating rate, as it is not practical nor desirable to attempt to monitor and change the plating material present in the bath solution to meet changing conditions in the amount of exposed metal surface that might being plated because of a deteriorating support rack.