USE AN APRON
Although you may look weird, it is well worth using an
apron. Find a white or neutral color with no pockets. Do
not use an apron with a busy design in case a component
decides to fall on you (or the floor). Pick up some Velcro©
and sew or glue it on the top side of the apron in the
two corners and also in the center of the bottom edge (I
usually attach three squares of Velcro.) Refer to Figure 2A.
Stretch the apron out, and put three 4” strips under
the edge of the table where the Velcro strips are. This will
allow flexibility when using the apron (Figure 2B).
Now, if something decides to fly off your work area, it
will be easier to retrieve it.
MAKE UP NEEDLE PROBES
Nothing is more frustrating than to find a surface-mount resistor or capacitor that has gotten mixed up and
has no markings. Make up a set of probes using two 1.5”
needles. Solder the needles to a small length of flexible
wire and tin the other end. (This is becoming more of a
sewing article than an electronics one!)
When you find a strip of components and don’t know
what they are, you can pierce the package and measure.
This also makes it easier to identify the anode and cathode
of LEDs or diodes if the markings have rubbed off.
HOW TO SURFACE-MOUNT BY HAND
One of the tricks to surface-mounting is to have a very
steady hand and a board that will not move. I use double-sided tape. This will allow your forearms to rest on the
work bench. It is also great for sticking battery supplies to
Place the double-sided tape to the bench where your
arms will feel comfortable. Have it extend farther than the
board. Peel off the upper side of the tape and stick the
earring board to it. This makes it easy if a part is upside
down or the marking is on the wrong side. Just touch the
part to the tape and (it will stick) roll it.
Let’s try this with a green LED. Find the pads that have
a “G” and add a dab of tacky flux to both pads. Find a
green colored LED, locate its cathode (normally has a
marking on top), and place the cathode next to the G
marking. On the Christmas tree board, the cathode is
marked with the color of the LED. Solder the components
so they are horizontal and not vertical. (If they’re vertical
and you are right-handed, your tweezers “hand” will be in
your stomach.) Watch the LED cathodes on the right side
as they are opposite of those on the left side and center.
(Refer to Figure 3.) Remember to rotate the board, not the
The first thing I do is see if the board pad has enough
solder to tack the part. Most boards are tinned and many
components are also. Put a small dab of tacky flux onto
the pad and place the part onto it, holding it with the
December 2014 39
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■ FIGURE 1.
■ FIGURE 2A. ■ FIGURE 2B.