Our Buck-Boost PCB from OSH Park has arrived. This version uses more SMD components than the first version. This allowed us to reduce the area of the PCB by 35%. I immediately began applying flux and populating the board. Here are some images of the process:
The film on the gold plated pads is the flux. I positioned the first gate drive IC in this picture.
I then proceeded to solder all of the pins of the IC. This was done with a regular iron and flux. For surface mount work you don’t need an extremely fine iron. The surface tension of the solder causes it to have a tendency not to form solder bridged, when an appropriate amount of solder is used.
Chip capacitors were then soldered in place. We used many 1uF X7R ceramic capacitors because this was much more cost effective than using a single large capacitor. The capacitors must have a low ESR; electrolytic capacitors are out of the question.
The components for the snubber circuit were then populated. The snubber prevents destructively large voltage transients from developing when current through the inductor is interrupted.
Through hole components and the bottom side surface mount components were mounted. The populated board now resembles our original board.