The Shocking truth about Electro
Static Discharge (ESD)
 Everyone
has experienced it. You walk across a carpeted floor
to make your exit, you grab the doorknob, and then ZAP!
You just felt the shock of Electro Static Discharge
(ESD). While the shock factor of ESD causes surprise
and even discomfort to humans, it can cause significant
damage to electronic components and equipment. Walking
across a floor, however, is not the only way that Electro-Static
voltage is generated. Walking on vinyl flooring, handling
plastic bags or containers, working at a workstation
or simply using a chair with urethane padding are just
a few examples of tasks that can cause static to build.
Any environment where electronics are present, is especially
vulnerable to the effects of ESD. According to Paul
O'Shea, Associate Editor of Evaluation Engineering,
"ESD strikes quickly and silently; leaving a trail
of burned-out or weakened circuits. Controlling static
charge. . . is a challenge that [starts from] the floor
up."
A July 24, 1996 Wall Street Journal article noted a string
of ESD-related incidents. In Polk County, Oregon for instance,
ESD was apparently responsible for a malfunction of election-tabulation
equipment. "Suspecting an erroneous tabulation, technicians
advised officials to treat the carpet around the suspect
computer with fabric softener. A subsequent retabulation
proved that voters had actually approved, rather than rejected
a tax increase."
Recent research indicates that ESD may be responsible
for more than 25% of all integrated-circuit failures over
the complete lifecycle of parts in manufacturing and testing
as well as in the field. (Semiconductor Reliability News,
March 1993) While it is impossible to accurately calculate
the cost of ESD, it most certainly runs into the hundreds
of millions of dollars every year. And with the ever-growing
trend toward automation, controlling this cost is critical.
Adding to the complexity the situation is the fact that
many equipment failures due to ESD appear as latent results.
Robert F. Martin described in a 1997 Compliance Engineering
article that "in these situations, device damage may
not be immediately apparent but may show up later during
normal operation, often as an unexplainable failure." Simply
put, unprotected equipment is a blow-out waiting to happen.
One of the most common and versatile ESD protection products
is matting. ESD matting is also one of the most cost effective
devices for controlling static at workstations and around
sensitive equipment. In many cases there is no need to
rip up subflooring or to lay special carpeting to control
ESD. Because they are available in conductive and non-conductive
styles to protect both workers and equipment, the simple
use of a mat may be the most economical and practical protection
option.
Back to Top
|
