In-line color variation analysis to quantify the quality of electroplated deposits in high volume manufacture

Electroplating has a long tradition in manufacturing which has advanced from a decorative finishing process to a process that applies precious metals in specific areas with the net effect of changing the properties of the electroplated component. The challenges facing electroplating as a manufacturing process are both cost of manufacture and the assurance of quality. If one is to broadly examine the operation of a reel-to-reel electroplating line, a huge dependence on output quality is placed on the human operation aspect. In this paper focus was placed on removing some of the over dependence placed on the operator. Particularly in relation to the visual inspection process by developing a more consistent detection system with increased reliability and repeatability. This paper presents an innovative approach where in-line non-destructive techniques for evaluating metal deposit quality are developed through color vision. To establish the capabilities of color vision in electroplating a series of empirical tests within the production environment gave a good insight into the critical variables. To optimize the vision system, image control techniques were applied these included variation of illumination sources and intensity, part position and camera location. Finally to achieve full traceability of defects recorded, dedicated software was designed and developed to provide both feedback to the operator and database storage of results. Colour vision proves to be a viable detection technique for electroplating but each program is part specific and variations in the formed shape of the stamped part can hinder the success of the system. The significance of this vision application cannot be underestimated when one appreciates electroplating defects are predominately visual and this approach works to prevent visual defects being used in assembled connectors.