BTU Discusses its Next-generation Flux Management System

Estimated reading time: 4 minutes

At productronica 2019, Nolan Johnson spoke with Peter Franklin, managing director of BTU Europe, about BTU’s next-generation solder reflow flux management system—Aqua Scrub. A winner of the show’s Global Technology Award for Soldering, Peter breaks down the specifics of what makes Aqua Scrub such an intriguing technology.

Nolan Johnson: Peter, what is BTU exhibiting here at the show?

Peter Franklin: As always, productronica is a spectacularly good show, and this one is already looking very good. The first day has been extremely busy. We have Pyramax 125 at our booth, which is the second largest of the ovens that we do. This is a nitrogen-capable machine. We offer it in both an air only and as a dual-atmosphere nitrogen air machine. We also have our new flux management system, which we are just filtering into the marketplace. It’s called Aqua Scrub, and instead of using condensing technology—the conventional way to take the flux out of the atmosphere, out of the gas that you’re putting through these ovens—this uses a water-based scrubbing system to clean the flux. It then puts the gas back into the machine, having first dried it, using the condensing system. It’s revolutionary, and we’re very excited about it.

Johnson: What are the advantages of a product like Aqua Scrub?

Franklin: First of all, it’s much more efficient. A typical condensing system is about 30% efficient; it takes 30% of the flux out of the gas that you’re putting through it. This takes over 90%. If you were to look for something of comparable efficiency, you would have to look at a pyrolysis system—one that burns the gas and therefore extracts the flux by burning. The problem with those systems is that they typically use quite a lot of energy. Aqua Scrub uses very little energy and needs no additional facilities than the oven takes anyway. All you need to do is top up the system with potable (drinking quality) water.

Johnson: That makes it particularly easy to install and an effective system. If you’re scrubbing flux, then you have flux to manage in the wastewater.

Franklin: Exactly. You have a mixture. It filters down into a container, which then becomes a mixture of flux and soapy water effectively; you can it dispose of it as you would if you were cleaning condensers.

Johnson: Just a typical sewage treatment process for that? That makes it simple.

Franklin: It’s good. At the moment, we’re looking to retrofit it and upgrade existing BTU machines in the field. Then, the next step is to have it built into the machine itself as an option.

Johnson: Was this driven by customer demand?

Franklin: Flux management is always a big demand from the customers because it’s dirty and difficult to clean. With a condensing system, you have to clean the condensers on a regular basis. Depending on how much flux you’re putting through the machine, that can be quite an arduous task. Here, you eliminate manual cleaning. It’s extremely popular with the customers that we tried it with so far.

Johnson: That sounds like a pretty strong case for the development of a very popular item.

Franklin: We spent a long time developing this. We looked at several different methods of disposing of flux that would be efficient, clean, non-toxic, and, of course, nonpolluting; this ticks all the boxes as far as is possible. It’s greener and doesn’t increase the power consumption of the machine, which a pyrolysis system does quite significantly.

Johnson: It seems like there is a strong argument for this to be a retrofit option.

Franklin: We’ve even had people ask if we would retrofit it to non-BTU machines, but we’ve declined that.

Johnson: You’re onto something here. How is it being received at the show?

Franklin: Good. Everybody who has been on the booth has been interested in it, especially where you’re using a nitrogen atmosphere. You could use it for air, but people don’t typically have sophisticated means of removing flux on an air machine. We have a flux management system for air only, but it’s a filtration system. It’s sufficient, but where you’re running nitrogen, which is a much dirtier process—for instance, in the automotive industry, where it’s common to use a nitrogen atmosphere—then you have a real flux problem, especially with high-volume throughput. Aqua Scrub is a very good solution for that.

Johnson: Since some of our readers may not be all that familiar, let’s drill down on what you just said about nitrogen systems being dirtier. Why?

Franklin: In an air system, the atmosphere removes straight out of the machine. The product is cooling it in air so that you can extract from either side of the heated chamber. You keep all of that gas in the heated chamber and duct it straight out of chimneys. When you use nitrogen, you have to cool in nitrogen. Suddenly, you must have the exhaust at the very ends of the entire process chamber. Inevitably, as the gas cools in the cooler, it’s also going to precipitate flux. That’s the problem.

Johnson: Very intriguing. Peter, thanks for your time today.

Franklin: Thank you.