Page 1 Grounding Considerations for an Electrostatic-Protected Area TUTOR: SL HO rev 0608 Fundamental principles Fundamental principles in electrostatic-protected area (EPA) : • Electrically interconnecting all conductive and dissipative items—that is, bonding them; • and attaching them to ground; • an area free of differences in electrical potential - EPA Slide 1
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ESD 02- Grounding, TR53 and compliance plan [相容模式]
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Page 1
Grounding Considerations for an Electrostatic-Protected Area
TUTOR: SL HO
rev 0608
Fundamental principles
Fundamental principles in electrostatic-protected area (EPA) :
• Electrically interconnecting all conductive and dissipative items—that is, bonding them;
• and attaching them to ground;
• an area free of differences in electrical potential - EPA
Slide 1
Page 2
rev 0608
Choosing the Grounding System
Choosing the Grounding System
• AC Equipment Ground
• Auxiliary Ground
• Equipotential Bonding
Slide 2
rev 0608
AC Equipment Ground
Within EPA, the preferred ground is the AC equipment ground
• the third-wire terminal
• electrically bonds the AC equipment ground to the ground bus at the main service equipment panel of the facility
Slide 3
Page 3
rev 0608
Auxiliary Ground
Slide 4
For some purposes only:
- to keep away any ESD spikes or electromagnetic-interference signals from electrical equipment that is not attached to that system in an EPA
rev 0608
Auxiliary Ground
• RISK: the difference in potential that could exist between different grounding systems (AC grounding and the Auxiliary grounding)
• SO: auxiliary ground and ac equipment ground need to be bonded together whenever possible
• IF both grounding systems are present, resistance between AC and Auxiliary ground shall be < 25 ohms.
Slide 5
Page 4
rev 0608
Equipotential Bonding
appropriate for remote or field operations where equipment is being serviced and a properly set up EPA is not available
Slide 6
- Electrically interconnecting All things in the area
- everything within the system will be at some shared potential (potential vs Ground may be elevated).
- “No difference in potential within the handling system, no discharge is possible”
- ESD-susceptible items within the system can be safely handled
rev 0608
Next step in setting up the EPAEstablishment of a common-point ground
• The common-point ground device : can be anything, terminal strips, bus bars, copper cables, etc.
• All of the ESD technical elements—wrist straps, table mats, floor mats, and so on—are terminated, by means of their grounding wires, to the common-point ground.
Slide 7
Page 5
rev 0608
Common-point ground
• Common point ground – point to point < than 1ohm
Slide 8
rev 0608
Important notes:
• Metal bench tops (stainless steel worksurfaces) MUST be connected directly to AC equipment ground with no added resistance. – Avoidance of CDM issue.
• Wires used within the EPA shall be of sufficient strength, not to be inadvertently broken or disconnected.
• Resistance of the conductor from the groundable point ground of any ESD technical element (worksurface, floor, chair, wrist strap…) to common point ground shall not be greater than 1 ohm.
Slide 9
Page 6
rev 0608
Important notes:
• Resistance of conductor from common point ground to the AC equipment ground shall not be greater than 1 ohm
Slide 10
Measurement of the resistance of the ac equipment
End of section
Page 7
Compliance Verification of ESD ProtectiveEquipment and Materials ESD (TR53-01-06)
rev 0608
Worksurfaces
Test Equipment
• An integrated checker or meter, whether it is a single meter or a collection of instruments that are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
• One electrode
• Two test leads of sufficient length
• DC Ohmmeter
Slide 13
Page 8
rev 0608
Wrist Straps
Slide 14
Test Equipment• Integrated checker or meter, whether it is a single meter or a collection of instruments thatare capable of measuring from 5.0 x 104 ohms to at least 1.0 x 1010 ohms with a test voltagebetween 7 and 30 volts DC open circuit. Some integrated checkers require manual selectionto wrist strap resistance test ranges.• Hand-held electrode• One test lead of sufficient length
rev 0608
Footwear
Test Equipment
• Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring from 5.0 x 104 ohms to at least 1.0 x 1010 ohms with a test voltage
between 7 and 30 volts DC open circuit. Some integrated checkers require manual selection
to Footwear resistance test ranges.
• Hand-held electrode
• Foot electrode
• Two test leads of sufficient length
Slide 15
Page 9
rev 0608
Flooring
Test Equipment
• Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
• One electrode
• Two test leads of sufficient length
Slide 16
rev 0608
Garments (sleeve-to-sleeve test)
Slide 17
Test Equipment• Integrated checker or meter, whether it is a single meter or a collection of instruments thatare capable of measuring at least 1.0 x 1012 ohms with a test voltage of 100 volts(± 10%) DC open circuit.• Two electrodes• Two test leads of sufficient length• Insulative support surface
Page 10
rev 0608
Seating
Test Equipment:
• An integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
• One electrode
• Two test leads of sufficient length
Slide 18
rev 0608
Mobile Equipment (Carts)
Slide 19
Test Equipment• Integrated checker or meter, whether it is a single meter or a collection of instruments thatare capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts(± 10%) DC open circuit.• Electrode• Two test leads of sufficient length
Page 11
rev 0608
ESD test equipment
Slide 20
Field Meter Detects ESD Potential from any SourceMeasure ionizer performance