Production Preparation and Numerical Control in PCB Assembly

摘要

The paper analyzes numerical control problems arising in a component insertionline for printed circuit board mounting. Such a line consists of a number of fully automated placement machines, connected by an automated, carrierless conveyor system. At each machine, the placement device consists of an arm equipped with a number of placement heads. Components are supplied to each machine by tape feeders which are placed at certain feeder positions along the machine. Before actually operating such a line, a careful production preparation phase has to be completed, specifying for each printed circuit board type the exact way in which such a board should be mounted. Problems arising in the production preparation phase include: the choice of heads to be mounted on the placement arm of each machine, the choice of components to be placed at each machine (workload balancing), an assignment of feeders to feeder positions on each machine, clustering of components to be placed in one pick-and-place move, and the sequencing of component insertions at one machine. Formulations and solutions for all these problems are given.