Back in mediaeval times many ‘things invisible’ like the vacuum, gravity, time, the plague and static electricity were awe inspiring if not a cause of great fear to the uninitiated. I wonder if the same applies to such seemingly unrelated stuff we struggle with in today’s electronics, like 0201-size surface mount components, electromagnetic radiation, microcontroller firmware and buried vias. All very real challenges in the Elektor Labs. Both invisibility and tiny dimensions initially create a feeling of unrest. When the transistor took over from the valve, a frequently heard complaint was that ‘it sure is much more efficient but you can’t see if the thing is alive or not’ and ‘these things die with not so much as a whisper’. Reportedly some radio & TV servicemen actually cut faulty transistors open to see if the clunkers could be fixed (and they could in some rare cases). Although far from being invisible, in the case of SMA components (a.k.a. SMDs) we heard reports from our readers like “more ended up in