Advances In Flat-Pack PCBs

November 28, 2018 by Brian Benchoff 44 Comments

Right now, we’ve got artistic PCBs, we’ve got #badgelife, and we have reverse-mounted LEDs that shine through the fiberglass substrate. All of this is great for PCBs that are functional works of art. Artists, though, need to keep pushing boundaries and the next step is obviously a PCB that doesn’t look like it has any components at all. We’re not quite there yet, but [Stephan] sent in a project that’s the closest we’ve seen yet. It’s a PCB where all the components are contained within the board itself. A 2D PCB, if you will.

[Stephen]’s project is somewhat simple as far as a #badgelife project goes. It’s a Christmas ornament, powered by two coin cells, hosting an ATTiny25 and blinking two dozen LEDs via Charlieplexing. The PCB was made in KiCAD, with some help from Inkscape and Gimp. So far, so good.

The trick is mounting all the components in this project so they don’t poke out above the surface of the board. This is done by milling a rectangular hole where every part should go and adding castellated pads to one side of the hole. The parts are then soldered in one at a time against these castellated pads, so the thickness of the completed, populated board is just the thickness of the PCB.

The parts used in this project are standard jellybean parts, but there are a few ways to improve the implementation of this project. The LEDs are standard 0805s, but side-emitting LEDs do exist. If you’d like to take this idea further, it could be possible to create a sandwich of PCBs, with the middle layer full of holes for components. These layers of PCBs can then be soldered or epoxied together to make a PCB that actually does something, but doesn’t look like it does. This technique is done in extremely high-end PCBs, but it’s expensive as all get out.

Still, this is a great example of what can be done with standard PCB processes and boards ordered from a random fab house. It also makes for a great Christmas ornament and pushes the boundaries of what can be done with PCB art.

Designing Space-Rated PCBs

November 26, 2018 by Dan Maloney 40 Comments

We’ve reduced printed circuit board design to practice so much that we hardly give a thought to the details anymore. It’s so easy to bang out a design, send it to a fab house, and have ten boards in your hands in no time at all. All the design complexities are largely hidden from us, abstracted down to a few checkboxes on the vendor’s website.

There’s no doubt that making professional PCB design tools available to the hobbyist has been a net benefit, but there a downside. Not every PCB design can be boiled down to the “one from column A, one from column B” approach. There are plenty of applications where stock materials and manufacturing techniques just won’t cut it. PCBs designed to operate in space is one such application, and while few of us will ever be lucky enough to have a widget blasted to infinity and beyond, learning what’s behind space-rated PCBs is pretty interesting.

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Put That DLP Printer To Use Making PCBs

November 24, 2018 by Tom Nardi 38 Comments

Now that these DLP printers are cheaper and more widely available, we’re starting to see hackers poking around the edge of the envelope to see what else the machines are capable of. [Electronoobs] recently got his hands on a couple of these printers, and thought he would do some experiments with using them for PCB production.

Rather than extruding molten plastic, these printers use light to cure resin layer-by-layer. In theory if the printer is good enough to cure the light-activated resin for a high resolution print, it should be able to do much the same thing with photosensitive PCBs.

Unfortunately, getting an STL out of a PCB design program takes a few intermediary steps. In the video after the break, [Electronoobs] shows his workflow that takes his design from EasyADA and turning it into a three dimensional object the DLP printer will understand. He does this with Blender and it looks pretty straightforward, but in the past we’ve seen people do similar tricks with Inkscape if that’s more your style.

Once you’ve grafted another dimension onto your PCB design, you may need to scale it to the appropriate size. [Electronoobs] notes that his STL for a 60 mm wide PCB came out of Blender as less than 2 mm wide, so you might need to break out the dreaded mathematics to find the appropriate scale value. Once the dimensions look good, you can load this file up into the printer as you would any normal print.

On the printer side of things, [Electronoobs] manually laminates UV photoresist film onto some copper clad boards with an iron, but you could skip this step and buy pre-sensitized boards as well. In any event, you drop the board where the UV resin normally goes, press the print button, and wait about ten minutes. That should give it enough time to expose the board, and you then proceed with the normal washing and acid bath process that hackers have been doing since time immemorial.

As [Electronoobs] shows, the results are quite impressive. While this still won’t make it any easier for you to do double-sided PCBs in the home lab, it looks like a very compelling method for producing even SMD boards with relative ease. This isn’t the first time somebody has tried using a DLP printer to run off some PCBs, but now that the technology has matured a bit it looks like it’s finally becoming practical.

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Etch Your Own Circuit Boards In Your Kitchen

November 16, 2018 by Brian Benchoff 43 Comments

Right now, you can design a PCB, send it off to a PCB fab, and get professional finished boards in a few days for less than a dollar per square inch. This is fantastic, and it’s the driving force behind ever-dropping costs of hardware development. That’s great and all, but you can make circuit boards at home, easily, and without involving too many toxic chemicals. That’s exactly what [videoschmideo] did, and the results are pretty good.

The process starts with a single-sided copper clad board that would be readily obtainable at Radio Shack if there were any of those around anymore. Once the circuit is designed, the traces and pads are printed (mirrored) out onto sticker backing paper. The toner from your laser printer is transferred to the copper with a clothes iron.

The tricky part about creating a PCB is taking away all the copper you don’t want, and for this tutorial [videoschmideo] is using a vinegar and hydrogen peroxide process. If you’re using stuff you can buy at the grocery store, you’re only getting 3% acetic acid and 3% peroxide, but given enough time and enough peroxide, it’ll do the job. After the board is etched, [videoschmideo] neutralizes the copper acetate produced with aluminum foil. The end product isn’t the safest thing in the world, but aluminum salts are much more environmentally friendly than copper compounds.

Making PCBs at home isn’t anything new, but it’s nice to be reminded that you can do so even with minimal effort and chemicals that you could rinse your mouth with. Once you do, though, you’ll probably have to drill some holes in the board. Yes, you could use a dremel, but a nice small drill press is a pleasure, and well worth the investment.

With Grinning Keyboard And Sleek Design, This Synth Shows It All

October 28, 2018 by Donald Papp 24 Comments

Stylish! is a wearable music synthesizer that combines slick design with stylus based operation to yield a giant trucker-style belt buckle that can pump out electronic tunes. With a PCB keyboard and LED-surrounded inset speaker that resembles an eyeball over a wide grin, Stylish! certainly has a unique look to it. Other synthesizer designs may have more functions, but certainly not more style.

The unit’s stylus and PCB key interface resemble a Stylophone, but [Tim Trzepacz] has added many sound synthesis features as well as a smooth design and LED feedback, all tied together with battery power and integrated speaker and headphone outputs. It may have been originally conceived as a belt buckle, but Stylish! certainly could give conference badge designs a run for their money.

The photo shown is a render, but a prototype is underway using a milled PCB and 3D printed case. [Tim]’s Google photo gallery has some good in-progress pictures showing the prototyping process along with some testing, and his GitHub repository holds all the design files, should anyone want a closer look under the hood. Stylish! was one of the twenty finalists selected for the Musical Instrument Challenge portion of the 2018 Hackaday Prize and is therefore one of the many projects in the running for the grand prize!

Putting A Motor Inside A Speed Controller

October 23, 2018 by Brian Benchoff 17 Comments

One of the more interesting hacks we’ve seen this year is [Carl]’s experimentations with making motors out of PCBs. Honestly, it’s surprising no one has done this before — a brushless motor is just some coils of wire and a few magnets; anyone can turn some coils into traces and make a 3D print that will hold a few magnets. This latest advancement is something else entirely. It’s a motor and an electronic speed controller all in one.

This project is a continuation of [Carl]’s PCB motor project, which started with him routing coils for a brushless motor as traces in a circuit board. Previously, we’ve seen [Carl]’s motor spinning on its own with the help of a small hobby ESC / motor controller meant for model planes and drones. This time, we’ve got something different. It’s an entire controller and motor, integrated into one single PCB.

This is a very, very small motor and ESC combo. The motor driver is a 3x3mm QFN package, and most of the other components are 0201. The main parts are a very tiny triple half-bridge motor driver and a PIC16F microcontroller. This PIC reads a hall sensor to detect the speed of the motor, and with just three pins — power, ground, and a PWM pin — this motor can spin at a set speed.

The future goals of this project are to make it work just like any other hobby ESC — just plug it into a servo controller and let ‘er rip. Since this motor with an integrated PCB requires only three connections, we’re looking at a great tool to add motion and rotation to any project. It’s fantastic, and we can’t wait to see something like this in robots, toys, and other home goods.

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Seeing A Webcam’s PCBs In A Whole Different Light

October 12, 2018 by Dan Maloney 13 Comments

When it comes to inspection of printed circuits, most of us rely on the Mark I eyeball to see how we did with the soldering iron or reflow oven. And even when we need the help of some kind of microscope, our inspections are still firmly in the visible part of the electromagnetic spectrum. Pushing the frequency up a few orders of magnitude and inspecting PCBs with X-rays is a thing, though, and can reveal so much more than what the eye can see.

Unlike most of us, [Tom Anderson] has access to X-ray inspection equipment in the course of his business, so it seemed natural to do an X-ray enhanced teardown and PCB inspection. The victim for this exercise was nothing special – just a cheap WiFi camera of the kind that seems intent on reporting back to China on a regular basis. The guts are pretty much what you’d expect: a processor board, a board for the camera, and an accessory board for a microphone and IR LEDs. In the optical part of the spectrum they look pretty decent, with just some extra flux and a few solder blobs left behind. But under X-ray, the same board showed more serious problems, like vias and through-holes with insufficient solder. Such defects would be difficult to pick up in optical inspection, and it’s fascinating to see the internal structure of both the board and the components, especially the BGA chips.

If you’re stuck doing your inspections the old-fashioned way, fear not – we have tips aplenty for optical inspection. But don’t let that stop you from trying X-ray inspection; start with this tiny DIY X-ray tube and work your way up from there.

Thanks for the tip, [Jarrett].