Page 421 - Hacking Roomba

402 Appendix A — Soldering and Safety Basics

Figure A-22 shows a standard anti-static bag used as a holder for an expensive part. These
bags are made of metalized plastic and are meant to keep all pins of a part at the same voltage
potential. What’s dangerous about static electricity is that it can put a several-thousand-volt
spike between two pins on a part. The current is very low, but the delicate internals of an IC
cannot withstand such a high voltage. Figure A-23 shows ICs pushed into anti-static foam,
which serves a similar purpose of keeping all the parts at the same voltage level.

FIGURE A-22: Anti-static bag with sensitive component on top

If you solder directly to ICs (which is not recommended unless you have to), make sure you use
a grounded soldering iron. All the better soldering irons (like the Weller ones) are grounded.
If you live in a humid climate, static prevention issues become less of an issue, but if you live in
the desert, take extra care. Once you get into the habit of not shifting too much in your chair
and occasionally touching the grounded chassis of your computer or work light, you don’t have
to consciously worry about static issues.