How researchers Alan Han and Quentin Bolsee are using the Neoden IN6C reflow oven to make electronics prototyping faster, more reliable, and more accessible at one of the world’s most forward-thinking labs.

CAMBRIDGE, Massachusetts — MIT’s Center for Bits and Atoms was launched by a National Science Foundation award in 2001 and continues to develop our understanding today as an interdisciplinary lab that explores the boundary between computer science and physical science, studying how to turn data into things, and things into data. Its work spans digital fabrication, programmable matter, and the global network of community makerspaces known as fab labs. To learn more about MIT’s Center for Bits and Atoms, check out their website here: http://cba.mit.edu/about/index.html

Today that research includes work by Alan Han, a PhD student, and Quentin Bolsee, a research scientist, who share a goal of making electronics prototyping faster, more accessible, and more composable. Some of the tools helping them get there include 3D printers, laser cutters, CNC machines, and the Neoden USA IN6C reflow oven.

A lab where bits become atoms

MIT’s Center for Bits and Atoms (CBA) is directed by Professor Neil Gershenfeld, who founded the global fab lab network, which has now grown to more than 3,000 labs across 160 countries. At any given time, CBA runs roughly 20 simultaneous research projects across a team of five to ten people, ranging from semester-long explorations to multi-year funded programs. The common thread is fabrication: turning ideas into things.

Quentin Bolsee earned his PhD at the Free University of Brussels and first encountered CBA after joining the fab lab community in Brussels before coming to MIT as a postdoc. For Bolsee, CBA provides a space to research and solve gaps in the industry such as “how do you make machines easier to prototype?” Bolsee says, “The idea is, if you can prototype an ID quickly, then you’re enabling all of those other makerspaces and Fab Labs and research labs to tailor their experiments a little more, because they can build very specific  types of equipment. That’s what I’m working on. That’s what motivates me.”

Alan Han studied electrical engineering at Purdue and spent about six years in industry working on next-generation connector technology, including systems that embedded circuits into the connectors themselves. When he came to MIT for a master’s degree, he ended up staying for a PhD. 

Circuits like Legos: Alan’s research

Alan’s research centers on the question “What does the 3D printer of an end-to-end electronics assembly look like?” What if there was a machine that allowed electronic circuits to not just be assembled, but provides a finished circuit that you can actually use? The system he’s building toward uses small, solderable PCB tiles, each carrying a specific circuit function. Arrange them in the right configuration, solder them together, and you have a working circuit. Take it apart, and the tiles are available for the next design. The goal is to keep that flexibility, to “take that prototyping process and make something that’s a little more robust." Alan Han continued this thought with "And then the other end of this is, how far can we go with this idea with respect to real-world applications?”

"Like Legos, you don’t really throw Legos away. If you’re done with them, you take them apart, you build something new. But the idea is to retain performance of a normal circuit as we’re trying to do that."

— Alan Han, PhD Student, MIT Center for Bits and Atoms

The tiles are currently around 6 by 6 millimeters: large enough to prototype with, small enough to compose into compact circuits. Alan is also exploring micrometer- and nanometer-scale versions in collaboration with MIT’s EECS department, pushing toward a future where the concept scales from maker benches toward manufacturable devices.

Building a working panel of tiles means running them through multiple reflow cycles. The tiles carry pads on both faces, requiring double-sided reflow, and many designs use a low-temperature tin-bismuth paste for the tile pads, a deliberate choice that keeps devices from detaching during later reflow passes.

Before the IN6C: toaster ovens and improvised jigs

Before CBA acquired the Neoden IN6C, Alan’s reflow process was functional but required a few extra steps. He worked through a hot air gun, a hot plate, and eventually a toaster oven, which handled single-sided boards well enough. But for the double-sided reflow, he needed to find a workaround, which was to elevate each panel on hardware so heat could reach both sides without components touching the rack. As Han described it: "I used a lot of screws, standoffs, and nuts, essentially to create a platform to raise it up so it could reflow both sides."

It worked, but it required a lot of manual setup and the potential for issues. Opportunities to scale were limited and there was a lot of guesswork and iteration.

The IN6C in practice

With the IN6C, the extra steps and manual setup were drastically reduced. The conveyor handles double-sided boards naturally, and Alan can feed panels continuously as the belt clears rather than managing individual batches in a static oven. He tuned a custom low-temperature tin-bismuth profile for the pads, and uses SAC305 for the devices.

The results have been meaningfully better: "I think it was a combination of new solder paste and the oven. The quality control has dramatically improved for sure on my end."

— Alan Han

After tuning, he was also able to bring the cycle time down to roughly four minutes per board. He can load about three panels into the entry section at once and keep feeding them as space opens up; by his estimate, with small, thin boards, that can add up to around a dozen moving through the oven at a time.

Room to grow: considering future improvements

As individuals who build their own equipment, Alan and Quentin had some ideas about where a machine like the IN6C could go. Warm-up time is real for an occasional user, and both were enthusiastic about the idea of an even smaller conveyor oven at a proportional price.

They also floated tighter computer control, the ability to export and share reflow profiles, and a smoother way to queue more than a few boards at once. Most of these are the kinds of refinements that come from people who clearly enjoy pushing a tool past its defaults, and the IN6C has earned that engagement by becoming a reliable part of the workflow.

From research bench to classroom

A recent development at CBA reframes what the oven could mean. The lab can now laser-engrave circuit boards and laser-cut solder stencils in-house, turning stencil production into a roughly ten-minute job. That capability is only about a year old, and for Alan and Quentin it changes the math: you can now design and make a board in about an hour.

Reflow is the piece that completes that loop, and it points toward CBA’s teaching mission. Each fall Alan and Quentin teach “How to Make Almost Anything,” a course that walks students through a full range of fabrication disciplines, a different process each week, from 3D printing to laser cutting to PCB design. The next step they talked about is bringing reflow into the student space rather than keeping it tucked away in the research lab: "Well, it would change the way we teach the class if we had that tool in the public space that we use for teaching."

— Quentin Bolsee

Alan pictured the day-to-day of it, expressing that, "I can imagine you turn it on, have it running, and then students can just pipe it through their boards relatively easily."

— Alan Han

Their vision aligns with what CBA has always been about: reducing the friction between an idea and a finished, functional thing. The faster and more reliable that process becomes, the more students and researchers can explore.

What’s next

For Alan, the clearest measure of the IN6C’s impact is scale. Runs of 10 to 20 panels now feel routine, and larger batches, like the hundreds of circuit boards a project such as conference badges might require, have moved from theoretical to genuinely feasible.

"If we did anything of that in-house, it would have to go through some sort of conveyor oven system like this. I wouldn’t consider it otherwise."

— Alan Han

CBA also has a long track record of research collaborations with industry partners, and Quentin noted that this kind of sponsored work is common at the lab. Alan mentioned that Neoden USA’s presence at upcoming events in the fab lab community could be a natural venue to explore where those conversations might lead.

For Neoden USA, the relationship with MIT’s Center for Bits and Atoms reflects exactly the kind of work we set out to support: researchers and builders pushing at the edge of what’s possible, who need equipment that keeps up. We’re proud to be part of that lab.