Issue link: https://iconnect007.uberflip.com/i/1243344
MAY 2020 I SMT007 MAGAZINE 79 if you wanted to, or—in some applications—to circulate the air back into whatever chamber you were pulling air out of so you can have a closed-loop system. Johnson: Is this typically installed with one unit per hood, or is it built into the central HVAC system? Mitchell: The systems that we manufacture are designed to be task-oriented. You're going to put an extractor for each of those tasks. If you had five lasers that were all next to each other, and each laser needed about 200 CFM to pull the air out, you could put one extractor that's generating 1,000 CFM. Typically, we put one extractor on each one of those units to leave you a lot more flexibility that way. This isn't something that we're going to hook up to an HVAC system and try to pull the whole build- ing into it. We're looking more at if you're hand soldering and putting an extractor with that operator or at least a hood with that oper- ator. If it's an inline oven, we're going to hook up one extractor per oven, and then lasers are the same thing. Johnson: Talk more about the dangers of the particulate that's being created: solder, sol- der fumes, flux, flux fumes, very small partic- ulates, and vaporized solids from the lasers. What are the dangers to humans from those? Mitchell: Essentially, you're looking at lung and breathing issues. With some of the chemi- cals that people work with, there can be either health limits to the amount of that material or even sort of allergic reactions to different chemicals that you're able to alleviate those. Johnson: What are the current trends or chal- lenges facing electronics manufacturing facil- ities with regard to environmental regulation and/or worker health regulation? Mitchell: The first challenge is how you're going to capture it. If you're working with enclosed systems like lasers and ovens, it's much eas- ier. If you're working with things that are more hand operations, you have to create ways to gather up that fume and particulate and get it drawn into an extractor. Johnson: What are some implementations you see in the field right now? Mitchell: If the unit that's creating or processing the material is enclosed, that's simple. There's generally going to be a port that's the vent, you connect the hose to it, and that hose also connects to our unit. If it's more of an open process—maybe an operator at a workbench hand soldering, touch-up conformal coating, or any of those types of operator processes— you're going to put either a flexible arm with a hood at the end of it that captures or have a smaller hood that you can configure onto the bench that creates the airflow and draws it in. The more enclosed that it gets, the bet- ter the capture is going to be—in part because you're removing the variability of the oper- ator. If you have an arm with a hood at the end—which has been used for capturing sol- der fumes for the longest time—they're effi- cient when they're in the right place. In the right place means the operator has to have the board and the hood close enough to each other that it's drawing the fumes in. Johnson: If you find that your work station is in a facility where you're close to a door, for example, when that door opens and closes, it changes the pressure and causes air nearby to move horizontally; now, the hood is no longer doing the job. Mitchell: Right, or an operator is warm, so they get a little fan and put it on their bench and blow the air on themselves across their work surface—not that I've ever seen that happen before (laughs). Johnson: There has been a lot of development lately in solder technology—changes to the flux, using fluxes in different ways, etc. Sol- ders have gone from containing a lot of tin and lead to lead-free solders, which has shifted the working temperatures. Of course, smaller and