There may be nothing new under the sun when it comes to etching PCBs with UV light, but [Heliosoph] has brought finer control to a used face tanner he bought that now exposes his boards in ~50 seconds ...

In dry etching, the trajectory of accelerated ions is non-uniform and non-vertical, due to collisions with gas molecules and other random thermal effects (figure 1). This has an impact on etch results ...

In this technique, fluorine-based plasma chemistry is used for silicon etching, which is combined with a fluorocarbon plasma process to offer sidewall passivation and enhanced selectivity to masking ...

While low-cost professional PCB fabrication has largely supplanted making circuit boards at home, there’s still something to be said for being able to go from design to prototype in an afternoon.