Care needs to be taken when handling printed circuit boards (PCBs) to prevent causing more damage than you are repairing. These are issues to be concerned about:
Wear safety glasses – Solder can splatter or leads can fly when trimmed, so wear safety glasses to protect your eyes anytime you are repairing a PCB.
Unplug and discharge your electronics – To prevent short circuiting the electronics and possibly electrocuting yourself, make sure the device you are repairing is unplugged and fully discharged. Capacitors and power supplies can hold a charge, so pay extra attention to make sure they are fully discharged. If there are any supplemental batteries, disengage those as well.
Prevent static discharge – Electrostatic discharge (ESD) is the sudden flow of electrons, or spark, from one surface to another. This is caused by a differential between the two surfaces, so one has more electrons than another. Nature loves equilibrium, so the electrons are exchanged to equalize the distribution. Wearing a grounded wrist strap and working on a grounded ESD-safe mat is the best way to prevent ESD. A wrist strap has a conductive surface that touches the skin, so can bleed off excess electrons. An ESD-safe mat works by a similar principle, so bleeds off a charge from anything on its surface. If working on a PC, you can clip the wrist strap directly to an unpainted area of the case.
Reduce contamination by washing hands and handling only the edges of the PCB – Contamination from your hands can create solderability issues and possibly lead to board failure from corrosion or dendritic growth. Silicone in your hand lotion or picked up from somewhere can create a barrier on contact areas which, in a soldering process, could prevent the solder from creating a good metallurgic bond. The solder may stick temporarily but pop off when exposed to any kind of thermal or physical stress. Contamination, like salt on those fries you had with lunch, are another leading cause of problems introduced in the repair process. Salt is an ionic soil which, when combined with moisture from the air, can cause corrosion. The ionic particles can also join to form dendrites, which can lead to current leakage and even short circuiting. Washing your hands and using only electronic-safe hand lotion is a good way to prevent this type of board failure. Also holding the board only by the edges without contacts (e.g. gold fingers) can help prevent depositing contamination on any critical areas.
Associated products:
https://www.chemtronics.com/static-free-hand-guard
https://www.chemtronics.com/static-free-mat-and-benchtop-reconditioner