DIY Reflow Plate Runs On USB Power Delivery

March 18, 2026 by Lewin Day 18 Comments

If you’re working with surface mount components, you’re likely going to want a reflow plate at some point. [Vitaly] was in need of just such a tool, and thus whipped up a compact reflow plate that is conveniently powered via USB-C.

This reflow rig is designed for smaller work, with a working area of 80 mm x 70 mm. There are two options for the heating element—either a metal core PCB-based heater, or a metal ceramic heater. The former is good for working with Sn42Bi58 solder paste at 138 C, according to [Vitaly], while the latter will happily handle Sn63Pb37 at 183 C if the dirty stuff is more your jam.

Running the show is an ESP32-C3-WROOM, which serves up a web-based control panel over Bluetooth for setting the heating profiles. Using Bluetooth over WiFi might seem like an odd choice at first, but it means you don’t have to add the hot plate to the local wireless network to access it, handy if you’re on the move. It’s also worth noting that you can’t run this off any old USB charger—you’ll need one compatible with USB Power Delivery (PD) that can deliver at least 100 watts.

If you’re needing to whip up small boards with regularity, a hotplate like this one can really come in handy. Files are on GitHub for those eager to build their own.

This isn’t the first time we’ve seen USB-C powering a small reflow plate. Of course, if you make your PCBs self heating, you can sidestep all that entirely.

USB-C Powered Hotplate Is Not For Food

July 25, 2024 by Lewin Day 18 Comments

Once upon a time, it was deemed mostly silly to try and schlep power from a computer’s ports. Then it was kind of amusing to do so with USB, and before you knew it, we were running whole laptops off what started out as a data connector. These days, it’s not unusual to run a soldering iron off USB-C, or, as [MarkTheQuasiEngineer] has done—a hotplate!

This hotplate is not for quesadillas, nor samosas. Instead, it’s a tiny hotplate for tiny reflow tasks. Given many PCBs are quite small, there’s no need for a huge hot plate to get your circuits assembled.

The device relies on metal ceramic heating elements to provide the warmth. An NTC thermistor is used for monitoring the temperature for accurate control, which is handled by the STM32 microcontroller that’s running the show. It also drives a small display indicating the mode of operation and current temperature. The STM32 controls the power going to the heating element from the USB-C feed with a stout power MOSFET.

Sadly, the project hasn’t been a complete success. With a PCB on the plate, [MarkTheQuasiEngineer] was only able to achieve peak temperatures of around 200 C. That’s not great for doing proper reflow, but it’s a start. He believes upgrading to a more powerful supply to feed the hotplate will help.

We’ve featured some other great reflow hotplates before too.
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A Compact SMD Reflow Hotplate Powered By USB-PD

January 9, 2024 by Dan Maloney 10 Comments

When it comes to home-lab reflow work, there are a lot of ways to get the job done. The easiest thing to do perhaps is to slap a PID controller on an old toaster oven and call it a day. But if your bench space is limited, you might want to put this compact reflow hotplate to work for you.

There are a lot of nice features in [Toby Chui]’s build, not least of which is the heating element. Many DIY reflow hotplates use a PCB heater, where long, thin traces in the board are used as resistive heating elements. This seems like a great idea, but as [Toby] explains in the project video below, even high-temperature FR4 substrate isn’t rated for the kinds of temperatures needed for some reflow profiles. His search for alternatives led him to metal ceramic heaters (MCH), which are commonly found in medical and laboratory applications. The MCH he chose was rated for 20 VDC at 50 watts — perfect for powering with USB-PD.

The heater sits above the main PCB on a Kapton-wrapped MDF frame with a thermistor to close the loop. While it’s not the biggest work surface we’ve seen, it’s a good size for small projects. The microcontroller is a CH552, which we’ve talked about before; aside from that and the IP2721 PD trigger chip needed to get the full 60 watts out of the USB-PD supply, there’s not much else on the main board.

This looks like a nice design, and [Toby] has made all the design files available if you’d like to give it a crack. Of course, you might want to freshen up on USB-PD before diving in, in which case we recommend [Arya]’s USB-PD primer.

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Solder Two Boards At Once With This Dual Reflow Plate

November 10, 2023 by Dan Maloney 4 Comments

Homebrew reflow projects generally follow a pretty simple formula: find a thrift shop toaster oven or hot plate, add a microcontroller and a means to turn the heating element on and off, and close the loop with a thermistor. Add a little code and you’re melting solder paste. Sometimes, though, a ground-up design works better, like this scalable reflow plate with all the bells and whistles.

Now, we don’t mean to hate on the many great reflow projects we’ve seen, of course. But [Michael Benn]’s build is pretty slick. The business end uses 400-watt positive temperature coefficient (PTC) heating elements from Amazon controlled by solid-state relays, although we have to note that we couldn’t find the equivalent parts on the Amazon US site, so that might be a problem. [Michael] also included mechanical temperature cutoffs for each plate, an essential safety feature in case of thermal runaway. The plates are mounted at the top of a 3D-printed case, which also has an angled enclosure for a two-color OLED display and a rotary encoder.

The software runs on an ESP32 and supports multiple temperature profiles for different solder pastes. The software also supports different profiles on the two plates, and even allows for physical expansion to a maximum of four heating plates, or even just a single plate if that’s what you need. The video below shows it going through its paces along with the final results. There’s also a video showing the internals if that’s more your style

We appreciate the fit and finish here, as well as the attention to safety. Can’t find those heating elements for your build? You might have to lose your appetite for waffles.

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Tour A PCB Assembly Line From Your Armchair

April 2, 2023 by Jenny List 15 Comments

Those of us who build our own electronics should have some idea of the process used to assemble modern surface-mount printed circuit boards. Whether we hand-solder, apply paste with a syringe, use a hotplate, or go the whole hog with stencil and oven, the process of putting components on boards and soldering them is fairly straightforward. It’s the same in an industrial setting, though perhaps fewer of us will have seen an industrial pick-and-place line in action. [Martina] looks at just such a line for us, giving a very accessible introduction to the machines and how they are used. Have a look, in the video below the break.

It’s particularly interesting as someone used to the home-made versions of these machines, to see the optical self-alignment and the multiple pick-and-place tools which are beyond the simpler pick-and-place machines you’ll find in a hackerspace. Multiple machines in a line are also beyond hackerspaces, so the revelation that the first machine is deliberately run slowly to avoid the line backing up is a valuable one.

At the end of the line is the reflow oven itself, through which the boards pass on a belt through carefully graded hot air zones. Certainly a step up from a toaster oven with an Arduino controller!

Sadly not all of us will be lucky enough to have such a line at our disposal, but pick-and-place projects come up here quite often. We did a teardown on the feeders from a Siemens machine a couple of years ago.

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A graphic showing the suggested footprint dimensions for 0402 parts

Want Better 0402 Reflow? Consider These Footprints!

February 1, 2023 by Arya Voronova 13 Comments

Assembling with a stencil is just that much more convenient – it’s a huge timesaver, and your components no longer need to be individually touched with a soldering iron for as many times as they have pads. Plus, it usually goes silky smooth, the process is a joy to witness, and the PCB looks fantastic afterwards! However, sometimes components won’t magically snap into place, and each mis-aligned resistor on a freshly assembled board means extra time spent reflowing the component manually, as well as potential for silent failures later on. In an effort to get the overall failure rate down, you will find yourself tweaking seemingly insignificant parameters, and [Worthington Assembly] proposes that you reconsider your 0402 and 0201 footprints.

Over the years, they noticed a difference in failure rates between resistor&capacitor footprints on various boards coming in for assembly – the size and positioning of the footprint pads turned out to be quite significant in reducing failure rate, even on a tenth of millimeter scale. Eagle CAD default footprints in particular were a problem, while a particular kind of footprint never gave them grief – and that’s the one they recommend we use. Seeing the blog post become popular, they decided to share their observations on 0201 as well, and a footprint recommendation too. Are your 0402 resistors giving you grief? Perhaps, checking the footprints you’re using is a good first step.

The 0402 and 0201 components are in a weird spot, where soldering iron assembly is no longer really viable, but the stencil+reflow approach might not be unilaterally successful when you start off – fortunately, that’s where writeups like these come in. Interested in learning stenciling? Get some solder paste, and read up on all the different ways you can put it onto your boards.

Internal Heating Element Makes These PCBs Self-Soldering

January 18, 2023 by Dan Maloney 56 Comments

Surface mount components have been a game changer for the electronics hobbyist, but doing reflow soldering right requires some way to evenly heat the board. You might need to buy a commercial reflow oven — you can cobble one together from an old toaster oven, after all — but you still need something, because it’s not like a PCB is going to solder itself. Right?

Wrong. At least if you’re [Carl Bugeja], who came up with a clever way to make his PCBs self-soldering. The idea is to use one of the internal layers on a four-layer PCB, which would normally be devoted to a ground plane, as a built-in heating element. Rather than a broad, continuous layer of copper, [Carl] made a long, twisting trace covering the entire area of the PCB. Routing the trace around vias was a bit tricky, but in the end he managed a single trace with a resistance of about 3 ohms.

When connected to a bench power supply, the PCB actually heats up quickly and pretty evenly judging by the IR camera. The quality of the soldering seems very similar to what you’d see from a reflow oven. After soldering, the now-useless heating element is converted into a ground plane for the circuit by breaking off the terminals and soldering on a couple of zero ohm resistors to short the coil to ground.

The whole thing is pretty clever, but there’s more to the story. The circuit [Carl] chose for his first self-soldering board is actually a reflow controller. So once the first board was manually reflowed with a bench supply, it was used to control the reflow process for the rest of the boards in the batch, or any board with a built-in heating element. We expect there will be some limitations on the size of the self-soldering board, though.

We really like this idea, and we’re looking forward to seeing more from [Carl] on this.

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