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CONDUCTIVE VERSUS
INSULATIVE ESD MATERIALS
The higher the
conductivity of the grounding system the faster electrons are
moved to ground. If electrons are moved to ground too quickly it
can damage components. If a flooring material is too
conductive it can present a safety hazard for the technicians.
The more insulative the material is the slower electrons are
moved to ground. Moving the electrons to ground too slowly easily allows
a static charge to accumulate drastically increasing the
failure rate of electronic components.
Conversion of Scientific to Number Calculator
Goal 1: Meet EOS
ESD S 2020-2007 with a combination resistance between the
technician / heel grounders and flooring <3.5E07
Goal 2: Provide
improved electrical conductivity of (standing) technicians for a
reduction of electrostatic accumulation (ESD). The flooring
system must move the charge to ground at least as well as a
technician wearing an esd wrist strap. The resistance of
the operator wearing a wrist strap has been shown to be
approximately 3.8E06.
CONDUCTIVE
|
<1.0E01:
(<10 ohms) |
Copper
flooring etc
Water etc |
(Note: Too
conductive! This range presents possible failure
mechanisms and safety hazards). |
|
1.0E02:
(100 ohms) |
|
1.0E03:
(1,000 ohms) |
|
1.0E04:
(10,000 ohms) |
ESD
Conductive Flooring
(>1.0E04
- <1.0E06) Electrical resistance in ohms to ground)
|
COMPLIANT:
MIL
Specifications and latest most stringent standards
|
|
1.0E05
(100,000
ohms) |
|
1.0E06
(1,000,000
ohms) |
|
>3.5E06
(technician and wrist strap resistance)
(>3,500,000
ohms) |
Technician
wearing esd wrist strap (current method of
grounding). |
COMPLIANT
BUT:
Straps become
easily disconnected from ground source, excess pull
on cords weakens wiring causing intermittent or
catastrophic failure. Extreme reduction in mobility,
occasional tripping hazard. Technicians are
not grounded when changing stations etc as wrist
straps are disconnected while moving. Technicians
must remember to use the wrist straps and properly
attach to ground source |
|
<3.5E06
Technician, heel grounders and
Titanium ESD
flooring resistance)
(<3,500,000
ohms) |
GOAL:
Technician wearing full sole foot grounders on
Titanium conductive flooring (proposed method of
grounding as replacement for wrist straps)
|
COMPLIANT
IMPROVED METHOD:
Electrical
conductivity is as good if not better than wrist
straps. Technicians experience freedom of
mobility (increased production). Redundant
protection (like wearing 2 wrist straps). Reduced
tripping hazard. Technicians ALWAYS grounded.
Technicians no longer have to remember to attach
straps to ground (eliminating potential for
operator error). |
|
1.0E07
(10,000,000
ohms) |
|
|
|
<3.5E07
(<35,000,000
ohms) |
Technician /
Heel Grounders / Flooring per EOS ESD S 2020-2007
97.1 |
COMPLIANT:
MIL Specifications and latest most stringent
standards |
|
1.0E08
(100,000,000
ohms) |
static mats,
static dissipative |
Note:
moves electrons to ground very slowly |
|
1.0E09
(1,000,000,000 ohms) |
current
interlocking
flooring (approximate). Wood, carpeting etc
Switchboard
matting, Plexiglas, etc |
(Note: Too
Insulative! This and the following ranges present
possible failure mechanisms due to Incomplete
electrostatic charge
decay. |
|
1.0E10
(10,000,000,000 ohms) |
|
1.0E11
(100,000,000,000 ohms) |
|
1.0E12
(1,000,000,000,000 ohms) |
INSULATIVE
Notes:
| K |
Kilo |
1,000 one thousand |
| M |
Meg |
1,000,000 one million
|
| G |
Gig |
1,000,000,000 one billion
|
| T |
Terra |
1,000,000,000,000 one trillion
|
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