Module 5: Digital Techniques and
Electronic Instrument Systems
5.12 Electrostatic Sensitive Devices
ESD: Electrostatic Discharge.
The sudden flow of electricity
between two objects.
Caused by imbalance of
electrons between the 2 objects.
A field created by tens of volts
between the 2 objects is enough
to damage a RAM module.
Walking on a vinyl floor can
generate up to 12,000V of static
ESD abbreviation can also mean
“Electrostatic Sensitive Device”
Common Electrostatic Sensitive Devices &
actions causing ESD.
Devices prone to ESD:
CMOS ICs (Chips)
Computer cards (CPU, GPU, etc.)
Actions causing ESD:
Opening a plastic bag.
Removing a tape from a roll or a container.
Transporting computer components around with trays or
Dry environments (non-humid) increase the possibility of
ESD Prevention of working personnel
Methods to remove
charge from the human
Touching metallic objects.
Other methods to prevent ESD when
working with electronic equipment
Avoid touching connections or
Ground all test equipment.
Use Antistatic mat:
Made a low resistance
material (10ΚΩ to 100ΜΩ) that
is grounded. It allows slow
Use Antistatic Agent:
A compound used that makes
the surface of a material
conductive, thus reducing or
preventing ESD. Usually
absorbs moisture from the air.
They are often added to jet
ESD Preventing Materials
Materials with resistance between 1ΚΩ & 1ΜΩ/m2
Materials with resistance between 1ΜΩ /m2 & 1ΤΩ /m2
Materials that attenuate current and electric fields.
Static electricity on the aircraft
The aircraft picks static charges from rain, cloud,
snow etc. (precipitation static)
• Strong charges developed between different parts of the plane
can break down the insulator between them.
• Problems caused by static electricity on the aircraft:
Material damage, Corrosion, Electromagnetic interference etc.
Corona Threshold and
Static electricity control
The Corona Threshold: High velocity gasses exiting
the engine Static electricity dissipates
surrounding atmosphere from sharp edges EMF.
Solutions to control static electricity:
Bonded (i.e. interconnection) of electronic equipment.
Wickes (to eliminate static electricity dissipation from