Post on 05-Apr-2018
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
1/12
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
2/12
ESD
Electrostatic Sensitive Devices (ESD) are
electronic components and other parts that are
prone to damage from stray electric charge.
Extensive (and permanent) damage to static
sensitive devices can result from mishandling andinappropriate methods of storage and
transportation.
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
3/12
STATIC ELECTRICITY
When two dissimilar, initially uncharged non-conducting materials are rubbed together, the frictionis responsible in transferring charge from one material
to.
The process of electron transfer known as'triboelectric charging'.
The amount of charge depends on factors like the rateof separation, humidity etc.
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
4/12
POSITIVE TRIBOELECTRIC
The following materials give up electrons and become positive when charged whenrubbed against other materials:
Air (most positive)
Dry human skin
Leather
Rabbit fur
Glass
Human hair
Nylon
Wool
Lead
Cat fur
Silk
Aluminium
Paper (least positive).
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
5/12
NEGATIVE TRIBOELECTRIC
The following materials tend to attract electrons when rubbed against other materialsand become negative when charged:
Wood (least negative)
Amber
Hard rubber
Nickel, copper, brass & silver
Gold and platinum
Polyester
Polystyrene
Saran
Polyurethane
Polyethylene
Polypropylene
Polyvinylchloride (PVC)
Silicon Teflon (most negative)
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
6/12
VALUE ELECTROSTATIC
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
7/12
CAUSES ESD
Electrostatic discharge from a human body
charged material to the ESDS device. Electrostatic discharge from the device
Field induced discharges
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
8/12
ESD WARNING
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
9/12
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
10/12
HANDLING ESD EQUIPMENT
Placards installed on the ESD LRU
The ESD printed circuit boards are identified with astatic sensitive placard.
Contaminated or unwanted material should be keptclear of the sensitive devices.
Connect the wrist strap into the Electrostatic GroundJack of the card file or recognised aircraft ESD ground
point. LRU or circuit boards are to be placed in the correct
conductive bag or container which must display an ESDlabel.
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
11/12
TRANSPORTING ESD EQUIPMENT
1. Use of wrist straps which must be worn when handling ESD
2. Use a heel strap
3. Use of static dissipative floor and bench mats.
4. Avoidance of very dry environments
5. Availability of ground jacks6. Use of grounded test equipment
7. Use of low-voltage soldering equipment and anti-staticsoldering stations
8. Use of anti-static insertion and removal tools for integratedcircuits.
9. Avoidance of nearby high-voltage sources
10.Use of anti-static packaging
7/31/2019 CAR 66 Module 5.12 Electrostatics Sensitive Device
12/12
WRIST STRIP