Custom PCB Is A Poor Man’s Pick And Place

February 4, 2025 by Dan Maloney 8 Comments

Surface mount devices have gotten really small, so small that a poorly timed sneeze can send your 0603 and 0402 parts off to live with the dust motes lurking at the edge of your bench. While soldering such parts is a challenge, it’s not always size that matters. Some parts with larger footprints can be a challenge because of the pin pitch, and getting them to land just right on the PCB pads can be a real pain.

To fight this problem, [rahmanshaber] came up with this clever custom PCB fixture. The trick is to create a jig to hold the fine-pitch parts securely while still leaving room to work. In his case, the parts are a couple of SMD ribbon cable connectors and some chips in what appear to be TQFP packages. [rahmanshaber] used FreeCAD to get the outline of each part from the 3D model of his PCB, and KiCad to design the cutouts; skip to 7:30 or so in the video below if you don’t need the design lesson. The important bit is to leave enough room around the traces so that the part’s leads can rest of the PCB while still having room to access them.

Using the fixture is pretty intuitive. The fixture is aligned over the footprint of the part and fixed in place with some tape. Solder paste is applied to the pads, the part is registered into the hole, and you’re ready for soldering. [rahmanshaber] chose to use a hot plate to do the soldering, but it looks like there’s enough room for a soldering iron, if that’s your thing.

It’s a simple idea, but sometimes the simplest tools are the best. We’ve seen lots of other simple SMD tools, from assembly jigs to solder paste stencil fixtures. Continue reading “Custom PCB Is A Poor Man’s Pick And Place” →

Electroplating DIY PCB Vias At Home Without Chemical Baths

January 31, 2025 by Maya Posch 18 Comments

Although DIY PCB making has made great strides since the early days of chemical etching, there’s one fly in the ointment: vias. These connect individual layers of the board with a conductive tube, and are essential for dual-layer PCBs, never mind boards with a larger layer stack. The industry standard way of producing them is rather cumbersome and doesn’t scale well to a hobby or prototyping context. Might there be a better way? This is the question that [Levi Janssen] set out to answer with a new home PCB manufacturing project.

The goal here is to still electroplate the vias as with the commercial solution, just without having to use chemical baths. This way it should be suitable for an automated setup, with a tool head that performs the coating of the via with a high-resistance conductive ink before the electroplating step, all without submerging the entire PCB. After an initial experiment showed promising results, [Levi] committed to a full prototype.

This turned out to be a bridge too far, so the prototype was scaled down to a simpler machine. This is where the main issue with electroplating one via at a time became clear, as a standard 0.3 mm via takes easily 10 minutes to electroplate, even with an increase in voltage. At that point ordering a PCB from China becomes the faster option if you have enough vias in the design. Fortunately [Levi] figures he may have some solutions there, so we’ll have to wait and see what those are in the next installment. The video is below the break.

Continue reading “Electroplating DIY PCB Vias At Home Without Chemical Baths” →

A History Of Copper Pours

January 31, 2025 by Al Williams 39 Comments

If you compare a modern PCB with a typical 1980s PCB, you might notice — like [lcamtuf] did — that newer boards tend to have large areas of copper known as pours instead of empty space between traces. If you’ve ever wondered why this is, [lcamtuf] explains.

The answer isn’t as simple as you might think. In some cases, it is just because the designer is either copying the style of a different board or the design software makes it easy to do. However, the reason it caught on in the first place is a combination of high-speed circuitry and FCC RF emissions standards. But why do pours help with unintentional emissions and high-speed signals?

Continue reading “A History Of Copper Pours” →

Audio On A Shoestring: DIY Your Own Studio-Grade Mic

January 14, 2025 by Heidi Ulrich 14 Comments

When it comes to DIY projects, nothing beats the thrill of crafting something that rivals expensive commercial products. In the microphone build video below, [Electronoobs] found himself inspired by DIY Perks earlier efforts. He took on the challenge of building a $20 high-quality microphone—a budget-friendly alternative to models priced at $500. The result: an engaging and educational journey that has it’s moments of triumph, it’s challenges, and of course, opportunities for improvement.

The core of the build lies in the JLI-2555 capsule, identical to those found in premium microphones. The process involves assembling a custom PCB for the amplifier, a selection of high-quality capacitors, and designing lightweight yet shielded wiring to minimize noise. [Electronoobs] also demonstrates the importance of a well-constructed metal mesh enclosure to eliminate interference, borrowing techniques like shaping mesh over a wooden template and insulating wires with ultra-thin enamel copper. While the final build does not quite reach the studio-quality level and looks of the referenced DIY Perks’ build, it is an impressive attempt to watch and learn from.

The project’s key challenge here would be achieving consistent audio quality. The microphone struggled with noise, low volume, and single-channel audio, until [Electronoobs] made smart modifications to the shielded wiring and amplification stages. Despite the hurdles, the build stands as an affordable alternative with significant potential for refinement in future iterations.

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Perfecting 20 Minute PCBs With Laser

January 5, 2025 by Al Williams 40 Comments

Normally, you have a choice with PCB prototypes: fast or cheap. [Stephen Hawes] has been trying fiber lasers to create PCBs. He’s learned a lot which he shares in the video below. Very good-looking singled-sided boards take just a few minutes. Fiber lasers are not cheap but they are within range for well-off hackers and certainly possible for a well-funded hackerspace.

One thing that’s important is to use FR1 phenolic substrate instead of the more common FR4. FR4 uses epoxy which will probably produce some toxic fumes under the laser.

Continue reading “Perfecting 20 Minute PCBs With Laser” →

Break Me Off A Piece Of That Open Source Serial Adapter

December 25, 2024 by Tom Nardi 11 Comments

We know, you’ve already got a USB to serial adapter. Probably several of them, in fact. But that doesn’t mean you couldn’t use one more — especially when it’s as as cleverly designed as this one from [Anders Nielsen].

The first thing you notice about this adapter, and the big departure from the ones that are likely littering your parts bin, is that it terminates in a full-size male DSUB9 connector. With the ability to be directly plugged into a RS-232 port, this adapter will certainly catch the eye of retrocomputer enthusiasts. With a clever arrangement of jumpers, you can even reconfigure the RX and TX lines to be straight-through or cross over as needed.

But if you’re working with something that doesn’t have a literal serial port, no worries. All of the lines coming from the CH340G chip are broken out to a header so you can connect it up to whatever device you’re working with via jumpers.

In fact, if you’re really sure you’ll never need that RS232 feature, the PCB is even designed in such a way that you can simply snap it off. Admittedly it might seem a little odd to get a device like this if you didn’t want that capability. But once broken off, it’s not like the components go to waste. [Anders] has designed the board in such a way that if you flip it over and install a right-angle header, you can use the RS232 segment on a breadboard.

But the list of features doesn’t stop there. There’s also a 3.3 V regulator on board that you can use to power external circuits, as well as breakouts for the data lines in the USB-C connector. In keeping with the theme of the device, that part of the PCB can also be snapped off if you want to use it elsewhere.

Most folks probably’ won’t need all the capabilities offered by this particular serial adapter, and that’s fine. We’re still happy that it’s out in the wild and available for the community to use and adapt as an open source project.

Continue reading “Break Me Off A Piece Of That Open Source Serial Adapter” →

Rudolph’s Sleigh On A North Pole PCB

December 20, 2024 by Heidi Ulrich 18 Comments

Each Christmas, [Adam Anderson], [Daniel Quach], [Johan Wheeler], and [Gustav Abrahamsson] (going by ‘the Janky Jingle Crew’)—set themselves the challenge of outdoing their previous creations. Last year’s CH32 Fireplace brought an animated LED fire to life with CH32V003 microcontrollers.

This year, they’ve gone a step further with the North Pole Circuit, a holiday project that combines magnetic propulsion, festive decorations, and a bit of engineering flair. Inspired by a miniature speedway based on Friedrich Gauss’ findings, the North Pole Circuit includes sleighs and reindeer that glide along a custom PCB track, a glowing village with flickering lights, and a buzzer to play Christmas tunes.

The propulsion system works using the Lorentz force, where vertical magnets interact with PCB traces to produce motion. A two-phase design, similar to a stepper motor, ensures smooth operation, while guard rails maintain stability on curves. A separate CH32V003 handles lighting and synchronized jingles, creating a cohesive festive display. As we mentioned in the article on their last year’s creation, going from a one-off to a full batch will make one rethink the joy of repetitive production. Consider the recipients of these tiny Christmas cards quite the lucky ones. We deem this little gift a keeper to put on display when Christmas rolls around again.

This annual tradition highlights the Crew’s knack for combining fun and engineering. Curious about the details or feeling inspired to create your own? Explore the full details and files on their GitHub.