Issue link: https://iconnect007.uberflip.com/i/992528
JUNE 2018 I PCB007 MAGAZINE 39 tant to get a good understanding of what is possible. There is no sub- stitute for a regular and deep study of the market just to keep an eye on what is going on with a view to un- derstanding how it could be applied to your own processes and machin- ery. A few years back, a customer asked me to include a high-pressure rinse as part of a dry-film pre-clean line. The requirement seemed a little unusual to me but since he had asked, I in- vestigated what we could offer. It be- came obvious that spray pressure was not a problem; we could offer various formats of pump and spray systems that could run at a pressure of over 150 Bar. The problem is that it is easy to damage material when you use this type of high-pressure system. We did some experiments and it seemed the best effect for his purpose (to remove particles stuck to the walls of drilled holes in certain exotic materials) was an 80 Bar pump and spray system. This was another example of a suc- cessful process development to over- come a process need. The high-pres- sure system can be switched off when processing thin and delicate materials to ensure they are not damaged. More commonly, we apply ultra- sonics to processes to enhance the cleaning of surfaces and the cleaning and wetting of holes. Often it would be possible to run the same process without ultrasonic drivers being included but the failure rate is likely to be higher. Every- one would like to have a zero-failure rate, and this is one way to get closer to it. To apply the ultrasonic system, immerse the process panel while it is passing the driver system, so it can't be used with a spray process but in most cas- es, it is usually possible to combine a mixture of flood and spray application to get the best effect. Different frequencies can be applied to give the most effective result depending on what you are trying to remove. The best effect is gained if the machine is designed for these types of features right from the start. In some cases, it may be possible to add features like ultrasonics to an existing line, but the effect is less likely to be perfect. Machines are usually designed to be as small as possible, so adding extra hardware is usu - ally a compromise and splitting a line to add an extra module in the middle is quite a tough job. Some parts of the manufacturing process re- quire the most even chemical effect possible Figure 2: Fluid movement inside the immersion tin chamber is driven by gentle propellers to minimise bubbles in the solution. This reduces maintenance and extends solution life.