Construction of component tapes for radial placement machines

Abstract

With a great variation of products, PCB assembling machines must be reconfigured often, but at the same time the efficiency of the assembly process should be kept high. In this paper we consider PCB assembly machines of the radial type, which are used for manufacturing robust electronics devices. In this machine type the components are brought to the assembly point by the means of a single component tape, and a robotic arm places them onto a bare PCB one at a time. The component tape is constructed on-line by a separate feeder unit (sequencer) composed of a set of slots storing component reels of various types. While the insertion of components to the tape does not normally delay their placements on the PCB, certain (broad) components delay the processing due to the operation principle of the sequencer, thus increasing the manufacturing time. We study the problem of assigning components to the sequencer in such a way that tape construction delay is minimized, give an integer programming formulation of the problem, and present an optimization algorithm to reduce the component insertion time caused by slow components. The results of this optimization algorithm show considerable improvement against a simple feeder assignment, in case of tape instances containing repeating sequences of components.