Mar 2024 AVR Electronics
After having completed several electronics projects from idea to finished gadget, and gained experience with self-designed PCBs, I felt it was finally time to face the elephant in the room. What elephant? The predominant electronics technology I never dared to touch before: SMT a.k.a surface-mount technology. Given that virtually all industrially produced electronics is surface mounted, and has been for several decades, there is a ceiling of how serious you can get before coming to terms with it. And that ceiling is pretty low.
As a hobbyist, there are obvious advantages and disadvantages to SMT, which, in one way or another, all come down to the greatly diminished physical size of the components. Reduced footprints lead to denser, and thus smaller and cheaper-to-order PCBs. That is pretty good in itself. Also, reduced physical dimensions virtually guarantee better electrical properties (less stray capacitance and inductance) – if you have a project where it matters. On the downside: those reduced footprints mean you basically lose your ability to work without a strong magnifying glass and desk lamp (the two ideally rolled into one), plus a tweezer in your (shaky) hand. All your fingers are now thumbs, get used to it.
The most obvious downside, however, is that you can no longer stuff components into a breadboard and experiment to your heart’s content. What was a nice (final) touch of quality and dedication is now a mandatory step: you really need to design a custom PCB and have it manufactured. Oh, and you need to be able to solder the parts. To me, this last step was the most intriguing of all. How do you solder under a microscope? Sure you can amplify your vision with the help of some optics, but your hand is still shaky and your soldering iron’s tip looks enormous under that looking glass, compared to the minuscule leads on all those ICs… and there are tons of them! The few SMD components I could not avoid on my earlier design (the micro-USB socket and LiPo charge controller chip on the EMMA SuperTorch) were tricky enough to solder with a regular iron.