An Efficient Assembly Sequencing Heuristic for Printed Circuit Board Configurations

This paper proposes a sequencing approach to develop a competent path for the printed circuit board assembly process. An efficient heuristic is developed that determines the component placement sequence, also referred to as the placement path. This NP-complete problem best resembles a Traveling Salesman Problem.1 Thus, it is inherently difficult. The heuristic approach is tested against a previously published subproblem as well as a real-life working board configuration. This heuristic is intended to provide a good, feasible component placement sequence for the assembly of a batch of printed circuit boards with a machine configuration consisting of a moveable X-Y positioning table and a tape-and-reel sliding feeder rack. Even with high speed assembly machines placing in excess of 40000 components per hour (cph), process improvements are possible by increasing the efficiency of the planned placement sequence. This heuristic is developed to identify an improved component placement sequence in a reasonable computation time to allow for future implementation of the methodology in applied situations where time constraints are unavoidable.