Today came in a new batch of PCBs from DirtyPCB.com, of which one is a new revision of the BlackMagicProbe. This revision is almost the same except it has a polyfuse in its powersupply to the target, a dedicated voltage regulator instead of P-FET, its programming header on the 90 degree on the side and a jumper for entering DFU mode. All this goodness is contained in less 5×2 cm PCB space, so quite a bit of PCB estate is left for other purposes and I used panelizing in EAGLE to try another brainfart of mine.
In most DIY projects where pogo pins are used people solder them directly to a wire or pad on a PCB. Despite it looks like it is the way to go, it isn’t. Pogo pins tend to wear out relative quickly as they are only rated for a couple of hundred ‘compressions’, also solder can sip into the pin and ruin its spring.
For the last few years, Hackaday has really been stepping up our game with marketing materials. Our t-shirts and swag are second to none, and last year we introduced the ‘Benchoff Buck’ (featured above), a bill replete with Jolly Wrencher EURions that is not yet legal currency. At least until we get a sweet compound in the desert, that is.
[Andrew Sowa] created the Benchoff Nickel. It’s a visage of yours truly emblazoned on a PCB, rendered in FR4, silkscreen, gold, and OSHPark’s royal purple. In doing so, [Andrew] has earned himself a field commission to the rank of lieutenant and can now reserve the dune buggy for a whole weekend.
The Benchoff Nickel was created in KiCad using the Bitmap2Component functionality. Planning this required a little bit of work; there are only five colors you can get on an OSH Park PCB, from white to gold to beige to purple (soldermask on top of copper) to black (soldermask with no copper). Luckily, the best picture we have of me renders very well in five colors.
The Bitmap2Component part of KiCad will only get you so far, though. It’s used mainly to put silkscreen logos on a board, and messing around with copper and mask layers is beyond its functionality. To import different layers of my face into different layers of a KiCad PCB, [Andrew] had to open up Notepad and make a few manual edits. It’s annoying, but yes, it can be done.
The Benchoff Nickel can be found on Github and as a shared project on OSH Park ($22.55 for three copies). One little curiosity of the OSH Park fabrication process presented itself with [Andrew]’s second order of Benchoff Nickels. OSH Park uses at least two board houses to produce their PCBs, and one of them apparently uses a lighter shade of FR4. This resulted in a lighter skin tone for the second order of Benchoff Nickels.
This is truly tremendous work. I’ve never seen anything like this, and it’s one of the best ‘artistic’ PCBs I’ve ever held in my hands. It was a really great surprise when [Andrew] handed me one of these at the Hackaday Unconference in Chicago. I’ll be talking to [Andrew] again this week at the Midwest RepRap festival, and we’re going to try and figure out some way to do a small run of Benchoff Nickels.
Most of us who have dabbled a little in electronics will have made our own printed circuit boards at some point. We’ll have rubbed on sticky transfers, laser-printed onto acetate, covered our clothing with ferric chloride stains, and applied ourselves to the many complex and tricky processes involved. And after all that, there’s a chance we’ll have ended up with boards that were over or under-etched, and had faults. For many the arrival of affordable online small-run professional PCB production from those mostly-overseas suppliers has been a step-change to our electronic construction abilities.
[Fran Blanche] used to make her own boards for her Frantone effects pedals, but as she admits it was a process that could at times be tedious. With increased production she had to move to using a board house, and for her that means a very high-quality local operation rather than one on the other side of the world. In the video below the break she takes us through each step of the PCB production process as it’s done by the professionals with a human input rather than by robots or ferric-stained dilettantes.
Though it’s twenty minutes or so long it’s an extremely interesting watch, as while we’re all used to casually specifying the parameters of the different layers and holes in our CAD packages we may not have seen how they translate to the real-world processes that deliver our finished boards. Some operations are very different from those you’d do at home, for example the holes are drilled as a first step rather than at the end because as you might imagine the through-plating process needs a hole to plate. The etching is a negative process rather than a positive one, because it serves to expose the tracks for the plating process before etching, and the plating becomes the etch resist.
If you’re used to packages from far afield containing your prototype PCBs landing on your doorstep as if by magic, take a look. It’s as well to know a little more detail about how they were made.
This is how V-Grooves are cut into PCBs. V-Grooves are half-cuts into the PCBs that allow them to be snapped apart easily. Minimum V-Groove cut length in generally 8cm due to machine cutting length. V-Grooves must be cut across the entire PCB length, it is not possible to make short internal cuts.
This is from our PCB documentation at DirtyPCBs.com about check it out for more PCB manufacturing details.
PCB etching seems to be a subject that sharply divides our community into those who are experts in it and etch themselves every PCB they use, and those who have significant quantities of ferric chloride stained clothing in their past and for whom the advent of cheap commercial PCB manufacture and CNC milled PCB prototyping have been the best thing since sliced bread.
Your likely success when etching your own boards is most dependent on the quality of your preparation and your equipment. If you began your PCB career with etch-resist transfers and a permanent marker with a Tupperware tub of etchant, then later progressed to laser toner or photographic masking and a bubble etcher, you’ll understand this.
[Jan Henrik] has drawn our attention to his very nicely built PCB etching suite (Translation, German original) at the Warpzone hackerspace (Translation, German original) in Münster, Germany. The foil pattern is printed on transparency and exposed to UV light over a photoresist coated board with a vacuum pump arrangement to ensure as good a contact as possible to the board for the sharpest result. They have two exposers, one for single sided and the other for double-sided boards, both are very well-built from what looks like plywood.
The attention to detail continues with a home-made magnetic stirrer and heated bubble etching tank Their etchant of choice is sodium persulphate, so there are none of those brown ferric chloride stains.
PCB etching is nothing new, indeed we have covered the subject extensively over the years. But we think you’ll agree, if you’re going to etch your own PCBs you should have as good a set-up as you can, and Warpzone’s PCB suite is rather well put together. Those of us in spaces with lesser facilities should be getting ideas from it.