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Static Solutions Inc.
Static Solutions Inc. - Ohm - Stat RT - 1000 Information
23
ANSI/ESD-S20.20-1999
be posted and clearly visible to personnel prior to
entry to the Protected Area. ESDS items shall be
packaged in ESD protective packaging while not in a
Protected Area. Access to the Protected Area shall
be limited to personnel who have completed
appropriate ESD training. Trained personnel shall
escort untrained individuals while in a Protected
Area. All nonessential insulators, such as those
made of plastics and paper (e.g. coffee cups, food
wrappers and personal items) must be removed
from the workstation. Ionization or other charge
mitigating techniques shall be used at the
workstation to neutralize electrostatic fields on all
process essential insulators (e.g. ESDS device
parts, device carriers and specialized tools) if the
electrostatic field is considered a threat.
6.2.3.2. Protected Areas Guidance
A Protected Area may be a single workstation (fixed
or portable), laboratory, room, building or any other
area with pre-designated boundaries that contains
materials and equipment designed to limit
electrostatic potentials. Humidity control may be a
key element in an ESD control program. Propensity
for charge generation and accumulation increases
with a reduction in humidity.
All process essential insulators that have
electrostatic fields that exceed 2,000 volts should be
kept at a minimum distance of 12 inches from ESDS
items. 2,000 volts is a measure of the electrostatic
field at the point of measurement and is not
necessarily directly related to the electrical potential
of the item. The accurate measurement of
electrostatic fields requires that the person making
the measurement is familiar with the operation of the
measuring equipment. Most hand held meters
require that the reading be taken at a fixed distance
from the object. Equipment manufacturers typically
specify that the object being measured needs to
have certain minimum dimensions. Objects smaller
than the minimum dimensions may not provide an
accurate reading. Additional guidance related to
Protected Areas may be obtained in ESD ADV 2.0.
6.2.4. Packaging
6.2.4.1. Packaging Requirements
ESD protective packaging and package marking
shall be in accordance with the contract, purchase
order, drawing or other documentation. When the
contract, purchase order, drawing or other
documentation does not define ESD protective
packaging, the Organization shall define ESD
protective packaging requirements for ESDS items
within the Plan. Packaging shall be defined for all
material movement within Protected Areas, between
job sites and field service operations.
6.2.4.2. Packaging Guidance
ESD protective packaging techniques vary widely.
Some of these types and techniques include low
charge generating bags and wraps, air space,
dissipative wrap, static shielding, conductive shunts
and the use of EMI/RFI shielding. All or some of
these packaging types may be used in conjunction
with one another to achieve a level of protection
commensurate with the item being protected. If the
user does not know the sensitivity of the items being
used, static shielding packaging should be used.
Materials include topically treated polyethylene
sheets and film, specially coated corrugated cartons,
carbon-loaded plastics, metalized plastic film and
various foils. The objective of ESD protective
packaging is to prevent a direct electrostatic
discharge to the ESDS item contained within and
allow for dissipation of charge from the exterior
surface. In addition, the packaging should minimize
charging of the ESDS item in response to an
external electrostatic field and triboelectrification.
Users should be aware that some packaging
materials may be humidity dependent and may have
limited shelf life. They may also lose static shielding
properties by crumpling, puncturing and folding.
Packaging materials may outgas, contaminate or
shed particles that may cause production-related
problems. It is important that the Organization
evaluate ESDS protective packaging materials for
process, storage and environmental compatibility.
6.2.5. Marking
6.2.5.1. ESDS Assemblies and Equipment
ESDS assemblies and equipment containing ESDS
parts and assemblies should be marked with an
ESD caution symbol, (i.e., EOS/ESD S8.1). The
symbol should also be located on equipment in a
position readily visible to personnel. In addition, the
symbol should be located in a position readily visible
when an ESDS assembly is incorporated into its
next higher assembly.
6.2.5.2. Packaging
ESD protective packaging should be marked in
accordance with EOS/ESD S8.1 or MIL-STD-2073-1
for Military applications.
6.2.6. Equipment
Further guidance regarding equipment can be found
in ESD-ADV-2.0.
6.2.6.1. AC Powered Tools
The working part of AC powered tools should be
capable of providing a conductive path to ground.
New powered hand tools such as soldering irons