Assembly time optimization for PCB assembly

Abstract

A printed circuit board (PCB) assembly task requires that a set of components be picked from their respective pickup locations and then be placed at their respective placement locations on the card being assembled. An automated assembly machine consists of a robotic arm which performs such an assembly task. The overall assembly time depends on two different decision variables: (i) the pickup locations of the components, and (ii) the sequence in which the pickup and placement of components is performed. In this paper we develop a technique based on integer programming to determine optimal values of both the decision variables. Since such a technique is computationally intractable, we also obtain near optimal solutions-that are computationally tractable-using the techniques of: (i) minimum weight matching for determining an optimal assignment of pickup locations, and (ii) traveling salesman problem for determining an optimum sequence of pickups and placements. Finally, we use simulations to compare the saving in overall assembly time using the techniques developed here and some of the techniques that are currently in use in industrial settings.