Tuesday, February 28, 2012 | Sjef van Gastel, Assembléon Netherlands B.V.
What can be done to reduce such changeover losses? Most changeover activities can be executed while the machine keeps running: Tape loading into feeders, feeder set-up in trolleys, and placement program preparation. Other changeover activities can be performed only while the machine is stopped: PCB transport system width adjustment, feeder trolley exchange, and nozzle exchange. However, we should ask ourselves: Is it possible to eliminate machine stoppage and perform these changeover activities while the machine is running?
Careful selection of the pick-and-place machine concept can solve this problem. Criteria to bear in mind are:
- Are sufficient feeder lanes available at the flow line to support multiple product set-ups?
- Is feeder exchange possible while the machine continues production?
- Is nozzle exchange possible “on-the-fly?”
- Can transport width adjustment be performed in small segments (one board length), safeguarding production in most of the flow line?
- Is instant placement program changeover possible?
- Can line set-up be verified off-line?
Well selected pick-and-place machines will reduce changeover time to limit output loss. Compare this with a Formula 1 pit stop, where all kinds of measures are taken to minimize time loss! Figure 1: The fastest changeover: A Formula 1 pit stop.
Let’s return to the Asian cell phone manufacturer. Suppose the company had installed 30 flow lines per plant, each with a capacity of 100,000 components per hour. This would reduce the number of changeovers needed per line to three, reducing output loss (one hour’s loss per 24 hours = 4%). Installing a dual-lane transport system would also give this advantage. As an additional benefit, production would continue on one production lane while changeover actions are performed on the other. This would result in almost zero output loss!
Want to produce a variety of products each day? Flexibility requirements are growing in importance. Careful selection of a pick-and-place machine concept can minimize changeover output losses. It is better to install multiple, small-capacity lines rather than a few large-capacity lines. Dual-lane machines will further reduce changeover output loss.
In addition to playing the clarinet in two bands, Assembléon’s Sjef van Gastel has another passion: SMT. He has been with the company since its start-up as a Philips division in 1979. As the current Manager for Advanced Development, he combines his experience as systems architect and machine designer to explore technical and business opportunities from emerging technologies. van Gastel holds many patents and is a frequent speaker at international conferences related to SMT. He is also the author of “Fundamentals of SMD Assembly,” which has become a standard piece of literature in the industry.