ESD can cause unseen damage to electronic components dur-
ing manufacture of electronic assemblies and equipment. If
the damaged component fails immediately, the result can be a
board that fails tests and requires rework. This represents lost
production and additional manufacturing costs.
Worse than this, a component may be partially damaged and
weakened. It may suffer a change or drift in characteristics. It
may remain within specification, but fail later when in use by
a customer. This is the most expensive type of failure, as it
can cause:
• Customer dissatisfaction
• Customer service personnel and facility cost
• Engineers time, possibly for on-site repair with travel,
and parts replacement
What is an EPA?
An EPA is an area that is maintained safe for handling static
sensitive components by keeping electrostatic fields and volt-
ages to an insignificantly low level. An EPA should have well
defined boundaries so that it is clear where the safe area is
entered and left.
• All personnel handling sensitive devices are grounded.
• All non-insulating and conductive objects are
grounded, so that electrostatic charge cannot build up
on these.
• Any surfaces on which ESDs are placed must be con-
nected to EPA ground. According to practical experi-
ence, we have chosen the overall electrical
performance of the reader in order to match its point-
to-point and point-to-ground resistance in a range
safely between 1 K ohm and 10
to avoid both hard grounding and electrical insulative
conditions.
• Insulating materials are strong ESD sources and so
they are excluded from the EPA where possible.
Where this is not possible special measures such as
ionisers are used to neutralise electrostatic charges.
Quick Reference Guide
ESD Information
12
ohm levels, allowing
23