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22 SMT007 MAGAZINE I AUGUST 2019 you need it to be. You're verifying that it's not where it shouldn't be and that your final prod- uct is within your accepted tolerance. The same is true with ovens and other systems having closed-loop controls to make sure that tempera- ture is being appropriately regulated. You don't want an incomplete cure that may potentially cause other concerns and considerations. A lot of what's required around these pieces of equipment is that they can collect data and gather information, but also that they're able to share it and take action on that information. Nordson ASYMTEK has been big on process controls for decades. For conformal coating, we came up with laser fan width control to make sure that the coating fan pattern is within tolerance and can make adjustments. Monitor- ing and controlling flow rate is critically impor- tant as well as making sure that fluid tempera- ture remains consistent, so the coating pattern is not affected by the environment; changes in environmental temperature can negatively impact your material viscosity, which would then change how your fluid comes out of the applicator. Johnson: Clearly, there is a lot going on with inter-machine communication and data cap- ture and reporting. That information then becomes useful up and down the manufac- turing flow. You're coordinating with other pieces of equipment, such as the reflow oven and curing process. To make sure that the sys- tems work correctly, has that required a lot of mechanical development work over the past couple of years? Sybert: That level of communication is where the industry is trending, especially once you start referring to conformal coating as the entire process from beginning to end and not just what each individual machine is doing. The first step to making sure that the entire process is running smoothly is to verify that each individual part is still maintaining what they're supposed to be doing and that they are functioning within the realms that they're sup- posed to. Individual machine process control is still critically important as well as being able what is required in the industry. The world's increasing dependence on electronics demands that these products need higher levels of per- formance and capabilities. The industry accepts this and defines what those require- ments and standards are. In addition to the ability to put down conformal coating, there's also the requirement to add degrees of overall process tracking and traceability. Everything that goes into the development of these elec- tronic components is recorded and monitored and can be researched retrospectively if an issue should arise. If there's a problem with an electronic component that comes up down the line, that can be addressed as well as similar issues. Then, the specific source of the prob- lem can be identified too. Johnson: That's an interesting point. The trace- ability requirement falls to the equipment, doesn't it? Sybert: Right, there are many different fac- tors that go into conformal coating, which is only one piece of the entire puzzle that goes together. Currently, people in the industry talk a lot about Industry 4.0 and IoT; much of that stems from data collection and traceability. Many systems involved in the process require closed-loop controls. Now, when we talk about conformal coating, the industry tends to focus on the conformal coating machine. But con- formal coating is an entire process itself from board preparation to coating. Then, your coat- ing quality has to be maintained by whatever curing process that you put in your manufac- turing line. Inspection is another critical com- ponent to verify that your coating processes are within the target. As we talk about closed-loop controls or the move to more automated operator-less facto- ries, pieces of equipment must be more inde- pendent in the sense that they monitor them- selves. They correct internally so that you don't require operators to intervene. With automated coating inspection, you can take out a lot of operator subjectivity by setting pass/fail crite - ria around what you're inspecting. You verify that you're putting the coating material where

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