Kongsberg EM 2040 MKII, Installation Manual

Page: 234 / 248

234
472405/A
About Electrostatic Discharge (ESD)
Electrostatic discharge (ESD) is the sudden flow of electricity between two electrically
charged objects. Such flow can be caused by contact, an electrical short, or dielectric
breakdown. Electrostatic discharge (ESD) can cause serious damage to printed circuit
boards and electronic modules.
Beware of Electrostatic Discharge (ESD)!
Note
When you handle electronic circuit boards and modules, you must beware of the dangers
of electrostatic discharge (ESD), both to yourself and to the equipment. In order to
ensure safe transport and storage, circuit boards and other electronic units will always
be wrapped in a clear plastic protective bag, and the bag will be sealed.
For correct and safe handling of printed circuit boards and electronic modules, you need
a suitable working area. The working area must be covered by an approved conductive
service mat that has a resistance of between 50 kΩ and 2 MΩ, and is connected directly
to a reliable earth point via its earthing cord. You - and all other service personnel
involved - must wear a wristband in direct contact with the skin. The wristband must be
electrically connected to the service mat..
What is Electrostatic Discharge (ESD)?
Electrostatic Discharge (ESD) is the transfer of an electrostatic charge between two
bodies at different electrostatic levels, caused either by direct contact or induction by
an electrostatic field. The passing of a charge through an electronic device can cause
local overheating, and it can also "puncture" insulating layers within the structure of the
device. This may deposit a conductive residue of the vaporized metal on the device,
and thus create a short circuit. Electrostatic Discharge (ESD) may result in a failures
or degraded performance of the device.
ESD can create spectacular electric sparks (thunder and lightning is a large-scale
ESD event), but also less dramatic forms which may be neither seen nor heard,
yet still be large enough to cause damage to sensitive electronic devices. Electric
sparks require a field strength above approximately 4 kV/cm in air, as notably
occurs in lightning strikes. Other forms of ESD include corona discharge from
sharp electrodes and brush discharge from blunt electrodes.
ESD can cause a range of harmful effects of importance in industry, including gas,
fuel vapour and coal dust explosions, as well as failure of solid state electronics
components such as integrated circuits. These can suffer permanent damage
when subjected to high voltages. Electronics manufacturers therefore establish
electrostatic protective areas free of static, using measures to prevent charging,
such as avoiding highly charging materials and measures to remove static such as
grounding human workers, providing antistatic devices, and controlling humidity.
http://en.wikipedia.org/wiki/Electrostatic_discharge (January 2014)
KONGSBERG EM 2040 MKII Installation Manual