Most people who have dabbled in the world of electronic construction will be familiar in some form with the process of producing a printed circuit board by exposing a UV sensitive coating through a transparent mask, before moving on to etching. Older readers will have created their masks by hand with crêpe paper tape on acetate, while perhaps younger ones started by laser-printing from their CAD package.
How about a refinement of the process, one which does away with the acetate mask entirely? [Ionel Ciobanuc] may have the answer, in the form of an exposure through an LCD screen. The video below the break shows how it’s done, starting with a (probably a bit too lengthy) sequence on applying the photo-resist coating to the board, and then sitting LCD on top of UV lamp with the board positioned at the top of the pile.
It’s an interesting demonstration, and one that certainly removes a step in the process of PCB creation as it brings the pattern direct from computer to board without an intermediate. Whether or not it’s worth the expenditure on an LCD is up to you, after all a sheet of acetate is pretty cheap and if you already have a laser printer you’re good to go. We’re curious to know whether or not any plastic components in the LCD itself might be damaged by long-term exposure to intense UV light.
Routing USB 3.1 traces app note from ON Semiconductor. Link here (PDF)
The introduction of USB Type−C has provided a significant launch opportunity for USB3.1 data rates across an array of platforms from portable to desktop and beyond. This proliferation of Type−C will certainly create challenges due to the high speed nature of the interface. High Speed USB2.0 presented enough of a system design challenge for tiny mobile device OEM’s trying to pass USB eye compliance. A 10X or even 20X increase in data rates will propagate that challenge far beyond the issues that were raised with HS. PCB traces in these systems must be treated as sensitive transmission lines where low-loss impedance control is king. Every effort must be made to make these paths as ideal as possible to prevent signal loss and unwanted emissions that could infect other systems in the device.
As a good electronic hobbiest tradition I started to design a businesscard from PCB material. Downside of all the businesscards (and PCBs in general) is the limited number of colors you can use: FR4, soldermask (with or without copper behind it), silkscreen or bare copper. Since the soldermask is fixed for both sides that was an extra limiting factor.
An out of the box solution I found was decal slide paper. This is a printable plastic film that is used to decorate ceramics or glass. There are clear and white versions and they can be found in most hobby stores. They are easily printed on by an inktjet or laser printer and have thus an infinite range of colors. For this experiment I bought clear film and designed the PCB with black soldermask (needed that color for the front side) and white silkscreen.
This is my first time designing a PCB for MSP430. I really like the NRF24L01+ booster pack but I would like something smaller to use for remote temperature sensors. With that in mind I’ve designed a 24.5 x 50 mm PCB (2 on a 5×5 cm prototype) featuring MSP430G2553 and an adapter for a 8-pin NRF24L01+ module using essentially the same pinout, with the intention of using the Spirilis library. There’s a jack socket to connect a 1-wire sensor (e.g. DS18B20), a 4-pin header to connect a temperature/humidity sensor (SHT22 or similar), a programming header that gives serial access, and 3 other general purpose I/O pins.
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.