3
1.4 - ICs / Chips
First, install the smallest IC - the Winbond
W25Q80DV flash memory chip (U104) in the
corner of the PCB. This is an SOIC-8
surface-mount package. It is the only
surface-mount part in the project. It comes in
a small black plastic tray which is a piece of a
"reel" of chips.
1. "Tin" only one of the IC's pads on the PCB
by applying a small amount of solder to it.
2. Using tweezers, peel off the clear plastic
protective film and remove the IC from the
reel.
3. Locate the "dot" in the corner of the chip indicating which pin is Pin 1. Match this to the dot
on the PCB silkscreen to orient the chip properly. (see photo)
4. Hold the chip with tweezers and place it on the pads in the correct orientation. At the
same time, heat the tinned pad with the soldering iron to "tack" the IC in place. Hold it
down with the tweezers to make sure the IC sits flat against the board while the solder
cools.
5. Apply soldering flux on the legs of the IC and its pads.
6. Apply some solder to the end of the iron, then touch that liquid solder to IC legs and pads
to flow solder into the joints using the pre-applied flux.
7. If solder bridges form between pads, remove them using additional flux and a clean iron
tip, or use solder wick (aka desoldering braid).
