An Error Correction Method for PCB Based on Machine Vision

Employing the machine vision system of a mounter, the location error of the first printed circuit board (PCB) can be a eliminated firstly by teaching method, then the location error and fabrication error of the other PCB's can be eliminated by identifying the shape, calculating the coordinate of the fiducial mark and comparing with the first PCB. Hence the repeat mounting precision of the mounter meets the mounting requirement. The error correction method for PCB mentioned in this paper was applied in the sample fullvision mounter. The mounting precision for fine pitch component can be controlled within 50 mm.