The PCB(Printed Circuit Board) industry continues to
adopt increasingly higher levels of integration and
achieving higher and higher levels of component
density. As a consequence, the tolerances on PCB
assembly become tighter and tighter. This causes an
increased need for reliable and accurate visual
inspection of PCB boards[1,2,3]. The manufacturing
of PCB circuits uses the SMT (Surface Mount
Technology). The SMT circuit assembly consists
of three major processes,