Brass Plaque Honors Brother

Brass plaques are eye-catching because no one makes them on a whim. They are more costly than wood or plastic, and processing them is proportionally difficult. [Becky Stern] picked the medium to honor her brother, who enjoyed coffee, motorcycles, and making things by hand. She made some playing card-sized pieces to adorn his favorite brand of hot bean juice and a large one to hang at his memorial site.

The primary components are a vertical salt water bath, DC power supply, metal to etch, scrap steel approximately the same size, and a water agitator, which in this case is an air pump and diffuser stone. You could stir manually for two hours and binge your shows but trust us and take the easy route. The video doesn’t explicitly call for flexible wires, but [Becky] wisely selected some high-strand hook-up leads, which will cause fewer headaches as stiff copper has a mind of its own, and you don’t want the two sides colliding.

There are a couple of ways to transfer an insulating mask to metal, and we see the ole’ magazine paper method fail in the video, but cutting vinyl works a treat. You may prefer lasers or resin printers, and that’s all right too. Once your mask is sorted, connect the positive lead to the brass and the negative to your steel. Now, it’s into the agitated salt water bath, apply direct current, and allow electricity to immortalize your design.

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RC Car Repair With Beer Can Solder Stencil

Sometimes it might seem as if your electronics are just jinxed. For [Niva_v_kopirce] it was the control board of his nephew’s RC car that kept frying the transistors. In situations like this, you can either throw it in the bin, invest your time in troubleshooting, hoping to find the error and try to fix it then, or get creative. He chose the latter, and designed and etched a replacement board.

Of course, etching your own PCB isn’t that noteworthy for the average Hackaday reader, although [Niva_v_kopirce] did go the extra mile and added purple solder mask to it, turning the stylishness definitely up to 11. This is also where it gets interesting, when you think of the solder mask as complementary layer for a solder paste stencil. Growing tired of manually applying solder paste, he thought to give a DIY stencil a try this time — using a beer can.

After cutting the can open and flattening it, along with some sanding, he transferred the cutouts from the solder mask onto it, and started etching holes in it. While the result may not be exactly precise, it did the job, especially for a homemade built.

Despite their convenience, stencils are still a rather exotic addition for hobbyists as they rarely pay off for a one-off project with limited SMD component usage. But maybe this was a new inspiration for you now. And if etching metal is outside your comfort zone, cutting plastic can be an alternative, as well as 3d printing.

Old Printer Becomes Direct Laser Lithography Machine

What does it take to make your own integrated circuits at home? It’s a question that relatively few intrepid hackers have tried to answer, and the answer is usually something along the lines of “a lot of second-hand equipment.” But it doesn’t all have to be cast-offs from a semiconductor fab, as [Zachary Tong] shows us with his homebrew direct laser lithography setup.

Most of us are familiar with masked photolithography thanks to the age-old process of making PCBs using photoresist — a copper-clad board is treated with a photopolymer, a mask containing the traces to be etched is applied, and the board is exposed to UV light, which selectively hardens the resist layer before etching. [Zach] explores a variation on that theme — maskless photolithography — as well as scaling it down considerably with this rig. An optical bench focuses and directs a UV laser into a galvanometer that was salvaged from an old laser printer. The galvo controls the position of the collimated laser beam very precisely before focusing it on a microscope that greatly narrows its field. The laser dances over the surface of a silicon wafer covered with photoresist, where it etches away the resist, making the silicon ready for etching and further processing.

Being made as it is from salvaged components, aluminum extrusion, and 3D-printed parts, [Zach]’s setup is far from optimal. But he was able to get some pretty impressive results, with features down to 7 microns. There’s plenty of room for optimization, of course, including better galvanometers and a less ad hoc optical setup, but we’re keen to see where this goes. [Zach] says one of his goals is homebrew microelectromechanical systems (MEMS), so we’re looking forward to that.

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Wire ECM built from an Ender 3

Simple Mods Turn 3D Printer Into Electrochemical Metal Cutter

We’re not aware of any authoritative metrics on such things, but it’s safe to say that the Ender 3 is among the most hackable commercial 3D printers. There’s just something about the machine that lends itself to hacks, most of which are obviously aimed at making it better at 3D printing. Some, though, are aimed in a totally different direction.

As proof of that, check out this Ender 3 modified for electrochemical machining. ECM is a machining process that uses electrolysis to remove metal from a workpiece. It’s somewhat related to electric discharge machining, but isn’t anywhere near as energetic. [Cooper Zurad] has been exploring ECM with his Ender, which he lightly modified by replacing the extruder with a hypodermic needle electrode. The electrode is connected to a small pump that circulates electrolyte from a bath on the build platform, while a power supply connects to the needle and the workpiece. As the tool traces over the workpiece, material is electrolytically removed.

The video below is a refinement of the basic ECM process, which [Cooper] dubs “wire ECM.” The tool is modified so that electrolyte flows down the outside of the needle, which allows it to enter the workpiece from the edge. Initial results are encouraging; the machine was able to cut through 6 mm thick stainless steel neatly and quickly. There does appear to be a bit of “flare” to the cut near the bottom of thicker stock, which we’d imagine might be mitigated with a faster electrolyte flow rate.

If you want to build your own Ender ECM, [Cooper] has graciously made the plans available for download, which is great since we’d love to see wire ECM take off. We’ve covered ECM before, but more for simpler etching jobs. Being able to silently and cleanly cut steel on the desktop would be a game-changer.

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Embrace The New, But Don’t Forget The Old

We were trading stories of our first self-made PCBs in the secret underground Hackaday bunker, and a couple of the boards looked really good for first efforts. Of course there were mistakes and sub-optimal routing, but who among us never connects up the wrong signals or uses a bad footprint? What lead me to have a hacker “kids these days have it so easy” moment was that all of the boards were, of course, professionally fabbed with nice silkscreens. They all looked great.

What a glorious time to be starting down the hardware path! When I made my first PCB, the options were basically laying down tape, pulling out the etch resist pen, or paying a bazillion inflation-adjusted dollars for a rapid prototype board. This meant that the aspiring hacker also had to have a steady hand and be at least casually acquainted with a little chemistry. The ability to just send your files out to a PCB house means that the barrier to stepping up your hardware game from plug-them-together modules is lower than it’s ever been.

But if scratching or etching your own PCB out of copper plate is very hands-on, very DIY, and very low-tech, it’s also very fast in comparison to even the most rushed service. Last weekend, I needed a breakout board for some eight-pin SOIC H-bridge chips for a turtle robot project with my son. Everything was hand-soldered and hot-glued in a Saturday afternoon and evening, so there was no time for a PCB order. A perfect opportunity for the Old Ways™.

We broke out a Sharpie, traced out where the SOIC pins would land, connected up the grounds, brought the signals out to friendly pads, and then covered the rest of the board in islands of copper just in case we’d need any prototyping space later. Of course, some of the ink lines touched each other where they shouldn’t, but before the copper meets the etchant it’s easy enough to scrape the spaces clear with a pin. The results? My boards look like they were chiseled out by a caveman, but they worked. And more importantly, we got it done within the attention span of a second grader without firing up a computer.

So revel in your cheap offshore PCB factories, hackers of today! It’s a miracle that even four-layer boards come back within a week without breaking the bank. But I encourage you all to try it out by hand as well. For large enough packages and one-offs, full DIY absolutely has the speed advantage, but there’s also a certain wabi sabi to the hand-drawn board. Like brush strokes in residual copper.

Scanning electron micrograph of a microfabricated lens array

Getting A Fly’s-Eye View With Microfabricated Lens Arrays

Atomic force microscopy, laser ablation, and etching with a witches brew of toxic chemicals: sounds like [Zachary Tong] has been playing in the lab again, and this time he found a way to fabricate arrays of microscopic lenses as a result.

Like many of the best projects, [Zach]’s journey into micro-fabrication started with a happy accident. It happened while he was working on metal-activated chemical etching (MACE), which uses a noble metal catalyst to selectively carve high-aspect-ratio features in silicon. After blasting at a silver-coated silicon wafer with a laser, he noticed the ablation pits were very smooth and uniform after etching. This led him to several hypotheses about what was going on, all of which he was able to test.

The experiments themselves are pretty interesting, but what’s really cool is that [Zach] realized the smooth hemispherical pits in the silicon could act as a mold for an array of microscopic convex lenses. He was able to deposit a small amount of clear silicone resin into the mold by spin-coating, and (eventually) transfer the microlens array to a glass slide. The lenses are impressively small — hundreds of them over only a couple hundred square microns — and pretty well-formed. There’s always room for improvement, of course, but for an initial attempt based on a serendipitous finding, we’d call it a win. As for what good these lenses are, your guess is as good as ours. But novel processes like these tend to find a way to be useful, and the fact that this is coming out of a home lab doesn’t change that fact.

We find this kind of micro-fabrication fascinating. Whether it’s making OLED displays, micro-machining glass with plasma, or even rolling your own semiconductors, we can’t get enough of this stuff.

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Garage Semiconductor Fab Gets Reactive-Ion Etching Upgrade

It’s a problem that few of us will likely ever face: once you’ve built your first homemade integrated circuit, what do you do next? If you’re [Sam Zeloof], the answer is clear: build better integrated circuits.

At least that’s [Sam]’s plan, which his new reactive-ion etching setup aims to make possible. While his Z1 dual differential amplifier chip was a huge success, the photolithography process he used to create the chip had its limitations. The chemical etching process he used is a bit fussy, and prone to undercutting of the mask if the etchant seeps underneath it. As its name implies, RIE uses a plasma of highly reactive ions to do the etching instead, resulting in finer details and opening the door to using more advanced materials.

[Sam]’s RIE rig looks like a plumber’s stainless steel nightmare, in the middle of which sits a vacuum chamber for the wafer to be etched. After evacuating the air, a small amount of fluorinated gas — either carbon tetrafluoride or the always entertaining sulfur hexafluoride — is added to the chamber. A high-voltage feedthrough provides the RF energy needed to create a plasma, which knocks fluorine ions out of the process gas. The negatively charged and extremely reactive fluorine ions are attracted to the wafer, where they attack and etch away the surfaces that aren’t protected by a photoresist layer.

It all sounds simple enough, but the video below reveals the complexity. There are a lot of details, like correctly measuring vacuum, avoiding electrocution, keeping the vacuum pump oil from exploding, and dealing with toxic waste products. Hats off to [Sam’s dad] for pitching in to safely pipe the exhaust gases through the garage door. This ties with [Huygens Optics]’s latest endeavor for the “coolest things to do with fluorine” award.

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