reflow

91 Articles

New controller PCB shown below the original one. The new PCB has an ESP module with an antenna, a lot of support circuitry, and all the same connectors that the original board does.

Controller For 946C Hotplate Adds Reflow Profile Upload Over BLE

September 30, 2022 by 7 Comments

Reflow hotplates are a wonderful tool for PCB assembly if you can keep your designs single-sided. The 946C hotplate in particular has been on hackers’ radar for a while – a 200x200mm working surface hotplate available for under $100 is a decent investment. As with other reflow tools, it was a matter of time until someone made a replacement controller for it. This one, you’ll want to keep in mind – it’s a replacement controller project by [Arnaud Durand] and [Elias Rodriguez Martin], called Reflow946.

Keeping to best practices, the board is a drop-in replacement for the stock controller – swap cables over and go. The host processor is an ESP32, and it lets you can program reflow profiles in using BLE, with a Python application to help. The whole design is open-source and on GitHub, of course – keeping with best 3D printing traditions, you can already order the parts and PCBs, and then assemble them using the hotplate you’re about to upgrade. As far as aftermarket controllers go, here’s no doubt this board gives you way more control in reflow and lets you compensate for any possible subpar calibration while at it. Continue reading “Controller For 946C Hotplate Adds Reflow Profile Upload Over BLE” →

Versatile Reflow Oven Controller Uses ESP32-S2

April 14, 2022 by 12 Comments

[Maker.Moekoe] wanted a single controller board that was usable with different reflow ovens or hotplates. The result is a versatile board based on the ESP32-S2. You can see a video of the board’s assembly in the video below.

The board sports several inputs and outputs including:

  • 2x MAX6675 thermocouple sensor input
  • 2x Fan output with flyback diodes
  • 2x Solid state relay output
  • 3x Buttons
  • 1x LED
  • 1x Buzzer
  • 1x Servo motor output
  • 0.96 inch OLED display

You could probably find a use for the board for other similar applications, not just ovens.

The video is oddly relaxing, watching parts reflow. It is like watching a 3D printer, no matter how many times we see it, we still find it soothing to watch. You can also see how he integrated the board with a toaster oven.

Overall, the board looks great and the workmanship is also very good. If you’ve never seen anyone set heat-set threaded inserts into a 3D printed piece, be sure to watch around the four minute mark.

We’ve seen plenty of oven projects. You can even use an Easy Bake oven.

Continue reading “Versatile Reflow Oven Controller Uses ESP32-S2” →

Reflow Hotplate Teardown Uncovers The Bare Minimum

March 10, 2022 by 13 Comments

[EEforEveryone] is trying to find a good hot plate for reflow soldering. After trying one cheap unit, he got another one. He was a bit underwhelmed. The grounding was suspect and the bed wasn’t totally flat. He tore it apart and was surprised that there was very little inside. While the construction wasn’t perfect, it was better than the previous unit. You can see a video of the teardown and review below.

Before powering it up, the first order of business was to rewire the ground system. After that, it was time to try it. However, by confusing Fahrenheit and Centigrade, he set the temperature much higher than necessary which creating a little smoke. Fixing the temperature helped, but there was still a bit of a smoky smell that eventually subsided.

The verdict? The hot plate worked well enough, but you probably do want to check the ground wiring before using it. That’s often a good idea where cheap equipment is concerned, anyway. But the real takeaway is that it looks like you could homebrew something equivalent without much trouble. The controller is an off-the-shelf module. A switch and a plug aren’t hard to figure out. The heating element could be a silicone heater or PCB heater meant for a 3D printer.

Of course, there are other options. You could use a wok. Or why not a waffle iron? You can also make a custom PCB.

Continue reading “Reflow Hotplate Teardown Uncovers The Bare Minimum” →

Mystery Effect Causing LEDs To Glow During Reflow

February 9, 2022 by 34 Comments

Sometimes you notice something small that nevertheless you can’t explain. [Greg Davill] found himself in just such a situation this week when he noticed some green LEDs glowing dimly when reflowing some boards. Naturally, [Greg] set out to investigate.

The green LEDs were wired up as power indicators, and [Greg] suspected that the polymer caps on the board might be generating a small current somehow that was causing the LEDs to light up ever so slightly. A simple test hooked a polymer cap directly up to a multimeter. When warmed with a heat gun, the meter showed a small current “in the 5-10 uA range.”

Going further, [Greg] soldered an LED to the cap and once again heated it up, this time to 100° C. The LED  glowed, continuing to do so for around 60 seconds with heat removed. The mystery also grew deeper – [Greg] noticed that this only happened with “fresh” capacitors. Once they’d been through one heat cycle, the caps would no longer light an LED when warmed up.

It’s a curious case, and has many speculating as to the causative mechanism on Twitter. Explanations from thermoelectric effects to chemical reactions inside the capacitor. If you’ve got the inside scoop on what’s going on here, don’t hesitate to let us know in the comments. Meanwhile, check out some of [Greg]’s best work – a glowing D20 dice featuring a whopping 2400 LEDs.

[Thanks to J Peterson for the tip!]

an up-close of the PCB hotplate

Using A PCB To Reflow PCBs – Take 2!

October 6, 2021 by 29 Comments

It’s not too hard to make your electronics project get warm. Design your traces too small, accidentally short the battery inputs together, maybe reverse the voltage going to your MCU. We’ve all cooked a part or two over the years. But what about making a PCB that gets hot on purpose? That’s exactly what [Carl Bugeja] did in his second revision of a PCB hot plate, designed to reflow other PCBs.

[Carl’s] first attempt at making a hot plate yielded lukewarm results. The board, which was a single snaking trace on the top of an aluminum substrate, did heat up as it was supposed to. However, the thin substrate led to the hot plate massively warping as it heated up, reducing the contact against the boards being soldered. On top of that, the resistance was much greater than expected, resulting in much lower heat output.

The new revision of the board is on a thicker substrate with much thicker traces, reducing the resistance from 36 ohms on the previous design to just 1 ohm. The thicker substrate, paired with a newer design with fewer slots, made for a much sturdier surface that did not bend as it was heated.

Continue reading “Using A PCB To Reflow PCBs – Take 2!” →

Iron Becomes SMD Hot Plate

July 4, 2021 by 20 Comments

Few things have changed our workshops more than surface mount components. In 1980 it would have been strange to see a hobby bench with a microscope, hot air equipment, tweezers, and all the other accouterments that are a necessity today. [Electronoobs] wanted a reflow hot plate and decided that he could repurpose a consumer laundry iron for the job. You can see the results in the video below.

Opening the iron revealed surprisingly simple circuitry, so the build has some additional parts along with a controller and an LCD, of course. The power requirement for the heating element is significant — 13 amps — so the plate uses a solid state relay to turn things on and off.

Continue reading “Iron Becomes SMD Hot Plate” →

Learn Bil Herd’s DIY Surface Mount Assembly Process

February 2, 2021 by 40 Comments

You can do your own Surface Mount Technology based PCB assembly with just a handful of tools and some patience. At the heart of my SMT process is stopping to inspect the various steps all while trying to maintain a bit of cleanliness in the process.

Surface mount or Surface Mount Technology (SMT) is the modern way to assemble Printed Circuit Boards (PCB) and is what is commonly seen when opening a modern piece of tech. It’s much smaller than the older Through-Hole (TH) technology where the component leads were inserted into holes in PCB, and act we called “stuffing” since we had to stuff the components into the holes.

A few specialized tools make this a lot easier, but resourceful hackers will be able to pull together a solder paste stencil jig, vacuum tweezers, and a modified toaster oven with a controller that can follow the reflow profile of the solder paste. Where you shouldn’t skimp is on the quality, age, and storage of the solder paste itself.

Join me after the break for my video overview of the process I use in my workshop, along with details of every step of my SMT assembly process.

Continue reading “Learn Bil Herd’s DIY Surface Mount Assembly Process” →