The image shows a breakout board for an NCP1402-based boost converter which steps-up 1.5v to 5v; these circuits are widely-used to power 5v (or nowadays 3.3v) from a single coin cell. (The board is my design, in KiCad, based on the manufacturer's recommended application.)
Of more interest here is the regulator component itself. This is the small 5-pin chip midway up the right-hand side of the board. It is a surface-mount SOT23-5 part, approximately 3mm by 1.5mm, far smaller than a grain of rice. Building this breakout board was more an exercise in seeing if it was possible to hand-solder these parts than anything else, since they are widely available for cheap on t'Internet.
So how did I do it? The first step was choosing a hand-soldered footprint for the part in KiCad. Then, once the boards had arrived, this part obviously had to be soldered on first:
- Apply solder to the pad under one of the further-apart pins (on the left in the picture)
- Place the chip over this pad with a tweezers and hold it in place
- Melt the solder on the pad until it flows over the pin
- Solder the other pin on the left-hand side
- Solder the three pins on the right-hand side together.
- With a desoldering pump (braid should work too), remove the excess solder from these three pins, so they are no longer shorted together.