01 March 2005
b. Attach wrist strap and place metal tools and
This damage can be caused by direct contact or by the
accessories on grounded bench surfaces.
electrostatic field associated with other charged items.
It is important to note that some modern military
c. Place conductive container on bench. Remove
circuits are sensitive to voltages as low as 25 volts.
component or assembly from package. Remove
The threshold of sensitivity or voltage level required for
shorting device if present. Handle components by their
a human being to feel a static discharge is approximately
body and place on conductive work surface/test fixture.
3500 volts. Therefore, ESD devices can be damaged
by maintenance personnel without their knowledge.
d. Compressed gases shall not be used to cool
ESD control measures must be employed to minimize
the impact of ESD damage on aircraft electrical/
electronic parts, assemblies, and equipment.
e. Test through connectors or tabs only.
8-10.2. CORROSION PREVENTIVE MAINTENANCE
f. After testing, replace shorting packages and
AND CONTROL. ESD devices must be protected from
static fields and/or static discharge when being
transported, handled, or stored. The following
g. Do not use Simpson 260 (or equivalent)
preventive measures will help provide this protection.
multimeter to test parts. Instead use the Fluke 8000A
a. Handle ESD devices only at protected work
stations. These sites eliminate all sources of ESD with
h. Dielectric strength tests are prohibited.
good grounding techniques by electrically bonding all
the surfaces, tools, and furnishings together. A
i. Only the use of anti-static type solvents is allowed.
protective stool should also be used and any support
equipment (soldering irons, text fixtures, test
j. Heat guns for test or curing are prohibited.
equipment, lights) must be grounded.
k. Drying lamps, photo spots, and thermal probes
b. ESD devices should be covered or packaged in
ESD-protective packaging when not being handled.
l. Do not remove components or assemblies from
c. Conductive carriers protect static sensitive
their sockets with power applied.
devices by shielding them from static. These carriers
are used to transport, store, and ship static sensitive
m. Apply dc voltages prior to applying signal inputs.
devices and should be placed on a conductive table
top. This allows safe removal of their contents. Example
n. The use of air to clean components/assemblies
of conductive carriers are conductive trays, boxes,
is prohibited unless a filtered ionizing air gun is used.
o. Do not use solvent ultrasonic cleaning bath for
d. Shunting mechanisms short circuit all the leads
of a device. This enables the entire device to be at the
same electrical potential and prevents ESD. Shunting
p. Device supply connections on the assembly
mechanisms for discrete components include shorting
should be made prior to making the ground connection.
clips, rings, and conductive foam. Conductive shunt
bars are a type of shunting mechanism for printed
q. Cure conformal coatings by normal ambient
circuit boards (PCBs).
curing or in an oven that contains grounding provisions
to prevent static charge buildup.
e. Nonconductive objects that can generate and
hold different static potentials on different areas on
their surface are poor conductors and cannot be
8-10. PREVENTION, TREATMENT, AND CONTROL
grounded.Static neutralizing equipment should be used
OF CORROSION ON ESD SENSITIVE EQUIPMENT.
to eliminate static charges on nonconductive objects.
8-10.1. GENERAL. ESD damage to aircraft electrical/
Use of an ionized air blower will neutralize static
charge by continuously blowing a cloud of ionized air
electronic devices can be caused by voltage or current
over the surface.