5.12 Electrostatic sensitive devices

3,365 views

Published on

Published in: Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
3,365
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
89
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

5.12 Electrostatic sensitive devices

  1. 1. Module 5: Digital Techniques and Electronic Instrument Systems 5.12 Electrostatic Sensitive Devices
  2. 2. Electrostatic discharge  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 electricity.  ESD abbreviation can also mean “Electrostatic Sensitive Device”
  3. 3. Common Electrostatic Sensitive Devices & actions causing ESD.  Devices prone to ESD:  MOSFETS  CMOS ICs (Chips)  Computer cards (CPU, GPU, etc.)  LED, Diodes  Actions causing ESD:  Opening a plastic bag.  Removing a tape from a roll or a container.  Transporting computer components around with trays or carts.  Dry environments (non-humid) increase the possibility of ESD.
  4. 4. ESD Prevention of working personnel  Methods to remove charge from the human body:  Touching metallic objects.  Wrist band.  Antistatic garment.
  5. 5. Other methods to prevent ESD when working with electronic equipment  Avoid touching connections or pins.  Ground all test equipment.  Use Antistatic mat:  Made a low resistance material (10ΚΩ to 100ΜΩ) that is grounded. It allows slow discharging.  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 fuels.
  6. 6. ESD Preventing Materials  Conductive Materials:  Materials with resistance between 1ΚΩ & 1ΜΩ/m2  Dissipative Materials:  Materials with resistance between 1ΜΩ /m2 & 1ΤΩ /m2  Shielding Materials:  Materials that attenuate current and electric fields.
  7. 7. 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.
  8. 8. 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 sharp edges).
  9. 9. Wicks
  10. 10. ESD signs

×