When people make their own printed circuit boards at home or in the workshop, they typically try to make things as simple as possible: that usually means single- or at most double-layer designs at a pretty hefty feature size, hand-soldering, and minimal complexity. Sometimes, though, you need to use smaller components, particularly when working with surface-mount parts - a bonus for the homebrew PCB maker, as surface-mount technology means you don't have to drill any holes through your board. To add to the excellent guides from Chris Holden we showcased back in June we now have Emiliano Valencia's latest Instructable: TinyDice.
Emiliano's TinyDice tutorial guides the reader through making some of the most impressive and compact homebrew printed circuit boards we've yet seen, as a means of building button-activated and - impressively - Arduino-compatible electronic dice. The project walks through every possible step: designing the circuit, gathering materials, transfer and etching of the circuit, addition of a solder mask layer - a step most home-etched circuit makers skip but which is a necessity when working with fine-pitched surface-mount parts - and even writing the final code such that it draws a bare minimum of power.
Emiliano's approach to PCB manufacture is far closer to that of a professional design house than a hobbyist, involving multiple mask layers and the creation of an aluminium stencil - made, ingeniously, from a flattened-out section of a pop can - for application of the solder paste. There's even the use of the reflow technique for soldering, but in place of a professional reflow oven or even a repurposed toaster Emiliano using a frying pan and a trivet made of mails to solder the components.While for many users sending design files off to a low-cost small-run manufacturing house like Dirty PCBs is going to be the most pain-free choice, it's hard to argue with Emiliano's impressive results - and we'd heartily recommend giving the full Instructable a read.
This project was my attempt at doing things right; making an SMD circuit, a professional quality PCB, a good PCB design, and an effective code, that allows for a very energy efficient project (when not in use, the whole thing consumes less than 0.1 micro amps, yes, less than 1 ten-millionth of an amp!).