Raytheon Systems manufacture circuit boards for several military and aerospace users. Most of these boards have to meet the most rigorous military specifications. Part of this specification concerns final surface coating of fully populated boards. At this late stage in production these boards are very valuable and Raytheon wanted to eliminate any losses.
The standard equipment which they were using did produce a small percentage of rejects at the coating stage. This was traced to a build up of coating material on the rollers driving the boards through the machine. This build up changed the effective diameter of the rollers and hence the speed at which the boards passed through the coater.
Pan Controls have supplied a single channel control system to monitor the board speed very closely and adjust the roller speed automatically using a servo motor. This comparatively simple task needs to be achieved with very high accuracy and consistency. The standard Pan controller has been achieving this for several months.
The two figures alongside show the dramatic improvement in quality. The result has been the virtual elimination of quality rejects. This application illustrates how solutions to production problems can be very straightforward.