its jaws in a horizontal position
about one inch above your work
surface; a small block of wood about
the size of a small breadboard; two
pairs of tweezers (one straight
locking and one non-locking, either
bent or straight); a straight dental
pick or something small and
reasonably pointed (even a
toothpick is fine); the prepared strip
board; and the SMD to be soldered.
2. Pick up the strip board, hold it
horizontally in your non-dominant
hand, and use the pair of non-locking tweezers (in your dominant
hand) to pick up and position the
SMD on top of the board as
accurately as you can. Don’t worry
about perfection at this point; we’ll
adjust the final position shortly.
3. Set down the non-locking
tweezers and pick up the locking
tweezers. Press them open, and then
use them to “pinch” the SMD
against the strip board. Refer to
4. Set down the non-locking
tweezers and insert the back end of
the locking tweezers — which are
still “pinching” the strip board and
SMD together — into the jaw of the
5. Place the small block of wood
under the strip board, and then
lower the tweezer so that the strip
board is resting on the wood. Check
out the photo in Figure 7 (which I
forgot to take until I was finished
with the entire board!).
6. Starting with the easiest pin to
reach, position your hot soldering
iron so that the tip is touching both
the end of the pin and the trace.
7. When the junction is hot
enough — using the smallest amount
of solder you can — solder the pin to
8. Solder the remaining pins in
the same manner. Figure 8 is a
photo of my strip board after the
SOT-223 was soldered in place. As
you can see, I used too much solder
on the tab and on the middle pin on
the right. However, the circuit would
still be perfectly functional.
■ FIGURE 6. SOT-223 held in place.
■ FIGURE 7. SOT-223
ready to solder.
■ FIGURE 8.
June 2013 19