Process Control in Solder and Reflow

Estimated reading time: 3 minutes

Nolan Johnson speaks with KIC’s Miles Moreau to get his perspective on topics such as wave process inspection (WPI), wave solder, and vacuum reflow, and how they will fit into Industry 4.0 and smart factories.

Nolan Johnson: Miles, as general manager for EMEA, Americas, and Australia, you’re watching what’s going on in business around the globe. What are the general market trends?

Moreau: The market trends I’m seeing—and it’s been interesting the way some of this has progressed—is a change of what makes the most sense to effectively, from a global economy standpoint, produce and deliver product for the OEMs. People say, “We can do it over here in Asia—specifically in China— very effectively, and at a very low cost,” but then you start to see these disruptions, and that mindset has changed.

That was just magnified by the pandemic, to where the market trends are localizing distribution points and manufacturing. Now you move from the OEM to EMS companies, and we will need to be more flexible and agile at meeting our customers’ demands, not just in some manufacturing base, but anywhere that they want to move production; we must have systems in place to manage that. If I’m an EMS company, they may say, “I want you to build over here now, but you’d better build it exactly the same way you were building it in this spot.” Especially when you compare OEM manufacturing vs. contract manufacturing (but it applies to both), they want to be able to deliver the same product regardless of where it’s built, and they want to be able to shift something quickly and build it somewhere else.

I think that’s why smart factory trends have accelerated; I’ve noticed in Europe and lately in the U.S., you’re getting some manufacturing moving back to North America and they are looking at those capabilities, saying, “Yes, we’re getting some manufacturing back here, but we want to keep it here,” so we have to be just as agile about how we can manufacture. That’s where these smart factory trends create the ROI; then I can say, “Here’s the best way to manage that and compete against these lower cost manufacturing locations.”

Johnson: KIC has been working on some ongoing R&D throughout 2019-2020 that is just starting to roll out; tell me about it.

Miles Moreau: We’ve had good solutions and a reputation for great reflow-related solutions around profile setup, optimization, and monitoring or inspection during production. That has been KIC’s forte, and we do that across SMT assembly and semiconductor packaging. We’ve always had requests from our customers for other thermal processes, with wave being one in particular that’s handled on the profiling side. We have some good solutions that help them set up and do a check on the machine, but it’s always been a challenge during production.

Wave is a multifaceted process of fluxing, preheating, and then soldering, as opposed to the oven being continuous where it all happens during the same process and flow. How do you adapt? Because the machines can be configured a lot differently—some have convection, some have IR heat, different ways of applying the heat, top and bottom zones, sometimes only bottom, two waves vs. one wave, all sorts of different things—that makes it really challenging. There are some aspects around the mechanics of the wave that are part of what the manufacturer is trying to monitor or keep track of.

A big challenge for us was to come up with something that a fixture can do; run it through the process, get preheat topside temperatures, ramp rates, make sure you’re activating the flux, and then capture some wave data as far as dwell time and parallelism with the fixture. But now what do you do during production? With a board going through a pot of liquid solder with a wave pumping and trying to have sensors and data collected so you can actually capture that data and do something in real time, this was our challenge.

To read this entire interview, which appeared in the May 2021 issue of SMT007 Magazine, click here.