ESD BASICS

What is ESD?
ESD Control Program
Implementation of ESD Control Products
Monitoring an ESD Control Program
Example of an EPA
Checklist for ESD safe handling
Definitions
ESD symbols
ESD Standards and Military Specifications
ESD Training and Instruction

 What is ESD?

ESD, ElectroStatic Discharge, is a spark, a microlightning bolt which passes from one charged conductive surface to another conductive surface. This incredible rapid transfer of what had heretofore been a static (unmoving) charge can cause fires,explosions, EMI, RF, heat, light and even sounds. It is this unseen, unfelt, unheard microlightning spark that must be controlled.

ESD Control Program

An ESD Control program includes the following points. By strictly complying with those points ESD damage can be minimized.

• ESD Training and Instruction.
• Handle ESD sensitive (ESDS) products only in an ESD Protected Area (EPA).
• Keep all conductors (including persons) on the same potential.
• Remove all "common" (charge generating) plastics from the EPA.
• Neutralize electrostatic charges on essential insulative materials by using ionization.
• Surround all ESDS with ESD safe packaging materials, except when they are being actively worked on.
  

Implementation of ESD Control Products

	Receiving & Incoming Inspection	Stores & Storage	Kitting	Automatic insertion	Manual Inspection
Wrist bands
Worksurface Mats
Floor mats
Shoe Grounders
Clothing
Shielding Bags
Conductive Foam
Conductive Containers
Field Service Kit/Mat
Ionizers
	Wave Soldering	Board Testing Rework	Equipment Assembly	Packaging & Shipping	Field Service
Wrist bands
Worksurface Mats
Floor mats
Shoe Grounders
Clothing
Shielding Bags
Conductive Foam
Conductive Containers
Field Service Kit/Mat
Ionizers

Monitoring an ESD Control Program

Once an ESD Control Program has been implemented, it is necessary to routinely monitor the program to make sure every element is working properly. A comprehensive ESD Control Program should included the following equipment:

• Static Locator or Static Field Meter :
  to demonstrate electrostatic charges or to determine whether electrostatic charges are present.

• Wrist band, footwear / shoe grounder tester:
  for testing wrist bands, grounding cords, footwear or shoe grounders.

• Surface Resistivity Meter:
  for testing worksurfaces, floor mats and flooring.

• Charged Plate Monitor:
  for testing ionization equipment.
  

Product	Equipment	Testing
EPA	Visual	Daily
Packaging	Visual	Daily
Wrist bands	GroundCheck Grounding Tester	Daily
Shoe grounders	GroundCheck Grounding Tester	Daily
Shoes	GroundCheck Grounding Tester	Daily
Worksurfaces	Surface Resistivity Meter	Monthly
Field Surface Kit	Surface Resistivity Meter	Monthly
Flooring	Surface Resistivity Meter	Monthly
Chairs	ChairCheck	Monthly
Ionizers	Ionizer Performance Analyzer	Monthly
Clothing	Resistivity Meter	Semiannual

Example of an EPA

1. Groundable wheels 2. Groundable surface 3. Wrist band and foorwear tester 4. Footwear footplate 5. Wrist band and grounding cord 6. Grounding cord 7. Ground 8. Earth bounding point (EBP) 9. Groundable point of trolley 10. Toe and heel strap (footwear)

11. Ionizer 12. Dissipative surfaces 13. Seating with groundable feets        and pads 14. Floor 15. Garments 16. Shelving with grounded surfaces 17. Groundable racking 18. EPA sign 19. Machine

Checklist for ESD safe handling

ESD Evaluation

• Assign and ESD coordinator.
• Which components are ESDS (ElectroStatic Discharge Sensitive)?
• Where are ESDS handled?
• Which processes can cause ESD?
• Where do ESDS products go to after leaving the plant?
• Quantify damage and loss due to ESD.

ESD Protection

Optimal ESD protection can be achieved by a combination of:

• ESD training and instruction;
• ESD protective products;
• Frequent monitoring of the above.

ESD Training and instructions

• Explain why ESD protection is necessary.
• Demonstrate the use of various ESD products.
• Adjust precautions to the practical working circumstances.
• Explain that ESD protection can generate a generous return on investment.

EPA (ESD Protected Area)

• ESD safe worksurface.
• Wrist band with grounding cord.
• Identification EPA ( Caution sign).
  Additional / optional :
• ESD safe floor, in combination with shoe grounders or ESD safe footwear.
• ESD safe chairs.
• ESD safe binders and document holders.
• ESD safe garments (gloves,coats, headwear).
• ESD safe tooling.
• ESD safe waste bins.
• Worksurface ionizers.

ESD protective packaging

• Checking of packaging of incoming goods.
• Packaging requirements of the product :
  - product sensitivity;
  - electrical properties;
  - mechanical properties;
  - water vapour transmission rate (WVTR)
  - single use or re-usability.
  

Definitions

IEC 61340-5-1 is listing the following packaging characteristics:

Low charging:
Packaging exhibiting properties which minimize any charge. (The terms astatic and antistatic should be avoided due to the different existing meanings).

Electrostatic discharge shielding:
A barrier or enclosure that limits the passage of current and attenuates the energy resulting from an electrostatic discharge such that the maximum energy from 1.000V human body model discharge is 50 nJ.

Electrostatic conductive:
Packaging with a surface resistance of  x10 ³ ohms & <1x10 ⁶ohms

Electrostatic dissipative:
Packaging with a surface resistance of x10 ⁶ohms & <1x10 ¹²ohms

Insulative:
Packaging with a surface resistance of x10 ¹²ohms

ESD symbols

The ESD susceptibility symbol incorporates a "reaching hand" in a triangle with a slash through it to indicate that the item so marked is susceptible to ESD damage and should not be touched without ESD safe handling tools.

The ESD protective symbol differs from the ESD susceptibility symbol, by the addition of an arc around the outside of the triangle and the omission of the slash across the hand and the triangle. It should be used to identify items that are specifically designed to provide ESD protection, such as for instance packaging. Instead of the asterisk a letter indicates the primary function of the packaging material :
S=Electrostatic Discharge Shielding
D=Electrostatic Dissipative
L=Low Charging
C=Electrostatic Conductive

ESD Standards and Military Specifications

IEC 61340-5-1	Protection of Electronic devices from Electrostatic Phenomena - General requirements.
IEC 61340-5-2	Specification for the protection of Electronic devices from Electrostatic Phenomena.
EN 100015-1	Protection of Electrostatic devices - Part 1 General requirements.
ANSI / EIA-541	Packaging of electronic products for shipment
ANSI / EIA-625	Requirements for handling ESDS devices
ANSI / EIA-583	Packaging material standards for moisture sensitive items.
ANSI / ESD-S20.20-1999	Program for the development of an ESD program
ESD ADV1.0-1994	Terminology for ESD
EOS / ESD-S8.1-1993	ESD Awareness Symbols
ESD STM4.2-1998	ESD Protective worksurfaces
ESD ADV53.1-1995	ESD Protective Workstations
ANSI / EOS / ESD-S6.1-1991	Grounding
ESD-S1.1-1998	Wrist straps
ESD-S9.1-1995	Footwear-Resistive characterization
ESD-S7.1-1994	Floor materials-Resistive characterization
ESD STM97.1-1999	Floor materials and footwear.
ESD STM12.1-1997	Seating-Resistive measurement
ESD STM2.1-1997	Garments
ESD S11.31-1994	Shielding Materials-bags
ANSI / EOS / ESD-S3.1-1991	Ionization
ESD ADV3.2-1995	Selection and acceptance of air ionizers
ESD STM5.1-1998	Sensitivity testing human body model
ESD STM5.2-1999	Sensitivity testing machine model
ESD ADV11.2-1995	Triboelectric charge accumulation testing
EOS / ESD-S11.11-1993	Surface resistance measurement
MIL-HDBK-263B	Electrostatic discharge control handbook
MIL-PRF-81705D	Barrier materials,flexible, electrostatic free, heat sealable
MIL-PRF-87893	Workstations, Electrostatic Discharge (ESD) control
MIL-STD-1686B	Electrostatic discharge control program.

ESD Training and Instruction

ESD training and instruction are essential for a successful implementation of an ESD control program. People need to be convinced of the necessity of ESD protection. Subsequently they need to know and understand the proper use of ESD protective products.

In-house ESD training
In-house training, geared towards the specific requirements of the customer.

ESD Video training
"A Strategic Attack on the Problem" is a video taped training program which uses an interactive learning method. It contains four modules of between 15 and 28 minutes each and sixty pages of notes. A special section of the notes is dedicated to "Training the trainer". The modules are sold either individually or as a set.