Kongsberg EM 2040C, Maintenance Manual

Page: 111 / 124

378511/A
109
Related topics
Packing instructions for storage or shipping, page 101
Circuit board unpacking and handling, page 106
About Electrostatic Discharge (ESD), page 109
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. 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 will
need a suitable workbench with an approved conductive service mat. This service mat
must be connected directly to a reliable earth point via its earthing cord. You must
wear a wristband in direct contact with the skin, and the wristband must be 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.
This 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
Equipment handling