TECHNICAL BULLETIN TB-2000
Installation and
Maintenance of ESD Mats
Introduction
09814
Made in the
United States of America
09817
The purpose of an ESD worksurface is to aid in the prevention
of damage to ESD sensitive components and assemblies from
electrostatic discharge. An ESD worksurface provides protection in
the following two ways:
1. Providing an antistatic worksurface area that will limit static
electricity generation.
2. Removing the charge from a conductive object placed on the
worksurface.
A dissipative worksurface having a surface resistance of at least 1
x 10
6
, but less than 1 x 10
9
ohms is recommended by worksurface
standard ANSI/ESD S4.1. Dissipative materials minimize the
generation of static charges, and will dissipate a charge slow
enough so that a spark will not occur. Dissipative materials are
usually the preferred choice for bench top worksurfaces.
Conductive materials are the quickest to remove a charge,
but they can also cause damage by discharging too rapidly.
Conductive materials are usually used as floor mats, which is
defined by ANSI/ESD S7.1 as less than 1 x 10
6
ohms.
Figure 3.
09814
with screw allows ground cord to be bolted to mat
to keep cord from disconnecting.
Common point grounds are designed to provide ground for
worksurface mats, wrist straps, and other items.
NOTE:
DO NOT DAISY CHAIN. Because of the high resistances
inherent to many types of protective surfaces, daisy chaining of
these materials can severely limit their ability to properly dissipate
and protect against static charges.
Figure 2. Other ground cords.
General Grounding Guidelines
1. ANSI/ESD S20.20 requires that all conductors in an ESD
protected area, including personnel, must be grounded.
2. The ESD ground must be tied directly to and at the same
potential as the building or “green wire” equipment ground.
3. Per ANSI/ESD S20.20, the ESD control program can in no
way replace or supercede any requirements for personnel
safety. Ground fault circuit interrupters (GFCI) and other safety
protection should be considered wherever personnel might
come into contact with electrical sources.
4. All electrical outlets should be verified for proper wiring
configuration, resistance or impedance and GFCI function when
the mat is installed and periodically thereafter.
COMMON POINT GROUND
Per ANSI/ESD S6.1, Grounding section 4.1.1 “Every element to be
grounded at an ESD protected station shall be connected to the
same common point ground.”
ESD Handbook ESD TR20.20 section 5.1.3 Basic Grounding
Requirements “The first step in ensuring that everything in an
EPA is at the same electrical potential is to ground all conductive
components of the work area (worksurfaces, people, equipment,
etc.) to the same electrical ground point. This point is called the
common point ground. The next step in completing the ground
circuit is to connect the common point ground to the equipment
ground (third wire, green).”
Common Point Grounds
A common point ground is defined by the grounding standard
ANSI/ESD S6.1, as:
1. A grounded device where two or more conductors are bonded.
2. A system or method for connecting two or more grounding
conductors to the same electrical potential.
Examples of common point grounds with ground cords are
illustrated below.
09835
WRONG!
RIGHT
09825
09837
09740
Figure 4. ESD mats should never be grounded in series, that is
daisy chained.
Figure 1. Typical common point grounds.
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way,
Canton, MA 02021-1407 • (781) 821-8370 • Web Site:
Desco.com
TB-2000
February 2015 Page 1 of 4
© 2015 DESCO INDUSTRIES INC.
Employee Owned
Grounding Methods
Method 1
(Grounding via ground cords)
1. Desco recommends using a common point ground cord when
grounding via ground cords. Most common point ground cords
will ground your ESD worksurface and provide banana jack
ground points for two wrist straps.
2. A common point ground should be installed at each workstation
and should be connected directly to a verified “green wire”
equipment ground. Only one groundable point should exist on a
worksurface.
2. Desco has three types of 10mm (0.395") field installable mat
grounding snaps. The first type is a screw-on snap kit Desco
item number
09864
Universal Snap Kit.
A. Determine the position of the grounding snap (one only
per mat) and type of fastener you will be installing (socket
or stud). Take precautions not to cut your hand, and punch
a hole through the material with a small Phillips screwdriver
or awl.
B. Remove the release paper from the circular common point
ground label and affix it so that it aligns with the hole on the
material.
C. Select one of the screws as follows:
Material less than 0.100" thick - short screw
Material greater than 0.100" thick - long screw
D. Insert the screw through the top on the snap stud or socket,
the washer, the label and the material. Affix the assembly
with the conical nut supplied with the kit and tighten down
the screw using a Phillips screwdriver.
E. Remaining will be either a 10mm stud or socket, and either
a long or short screw to be discarded or saved for another
application.
ASSEMBLE
SCREW, STUD,
WASHER, LABEL
AND CONICAL NUT
AS SHOWN
USE A PHILLIPS
SCREWDRIVER OR
AWL TO PUNCH
A HOLE IN THE
MATERIAL
Figure 5. Common point ground for each workstation.
3. Wrist straps should never be grounded through a worksurface,
as the added resistance of the worksurface material will
prevent the wrist strap from operating properly.
WRONG!
RIGHT!
Figure 8. Installing Universal Snap Kit on mat.
3. The second type of mat grounding snap is the push and
clinch snap. This snap is designed for use with any type of
soft mat material: dissipative, conductive or multi-layered. It is
recommended for use with three-layered material, because it
provides excellent contact with the internal conductive scrim
layer. It is recommended that before inserting this snap, the
mat be punctured with a sharp tool where the snap will be
placed. Take precautions not to cut your hand. Push and Clinch
snaps are available as a snap stud as item
09861
and as a snap
socket as item
09863.
A. Remove the release paper from the circular label and
affix it onto the mat material in the desired location.
B. Center the prongs on the snap assembly with the label.
Apply pressure to the snap until the prongs come through
the back of the mat, then clinch over prongs to secure snap
as shown in Figure 9.
Figure 6. Proper grounding of wrist straps.
4. Per ANSI/ESD S1.1, a current limiting resistor in the wrist strap
ground cord is recommended. If other than a one megohm
resistor, special marking in red is required.
For additional information on grounding we recommend Desco
Technical Bulletin
TB-2007.
Groundable Point Installation
1. Before installing a groundable point on your mat you must first
determine whether you will need a snap socket or stud, the
type of snap hardware and the location.
Figure 7. Three kinds of snaps.
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way,
Canton, MA 02021-1407 • (781) 821-8370 • Web Site:
Desco.com
TB-2000
Page 2 of 4
© 2015 DESCO INDUSTRIES INC.
Employee Owned
Figure 9. Installing push and clinch mat grounding snap.
4. The third type is the rivet style mat grounding snap. This type
of snap assembly is installed using a rivetting hand tool, item
09867.
Male snap studs and rivets are available as item
09856
and female snap sockets and rivets are available as item
09857.
Groundable point labels are not included with either the
item
09856
or
09857
snap kits.
3. The
09837
Multi Ground
Hub is designed for
use as either a multiple
grounding block or as a
common point ground.
The Multi Ground
Hub incorporates six
standard banana jacks,
and six terminations for
ring terminals (10-32
screw in threaded
holes). Note: Also
available as Desco item
19219
Ground Hub
Monitor
Figure 11. Mounting the
09837
to a table leg.
4. The
09740
dual bench mount allows the grounding of
two operators at one common point. The 09740 mounts
easily under the front edge of a workstation. For
detailed information on this common point grounding
device ask for Technical Bulletin
TB-2003.
Socket
Stud
Figure 10. Installation using a rivetting hand tool.
Common
Ground
Point
Worksurface Mat
Snap Ground
Do Not Hook
A Second
Surface or
Device Here
Selection of Common Point and
Floor Mat Grounding Systems
1. Determine the type of common point grounding system you will
use: barrier strip, bus bar, grounding block, or common point
ground cord. Desco recommends the use of common point
ground cords or our
09740
dual bench mount.
2. If you determine that you will use ground cords, you must
now determine the type of ground cord you will use for your
workstation grounds. ANSI/ESD S6.1 recommends that a
non-resistor ground cord be used to ground worksurfaces and
floor mats. However, cord may have a 1 megohm resistor for
non ESD puropses. Selection of the ground cord is determined
by user needs and specifications.
Wrist Strap
Ground
Equipment
Ground
Floor Mat
Ground
Snap
Figure 12.
09740
dual bench mount.
Desco Ground Cord Item Numbers
Model #
09814
09813
09817
09818
09820
09821
09825
09826
09835
09836
09837
09740
09741
1 Megohm
Resistor
Designed
for Floor
Mat Use
Designed for
Worksurface
Use
Wire
Length
15'
15'
10'
10'
Banana
Jacks
0
0
0
0
2
2
2
2
4
4
6
2
2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
10'
10'
15'
15'
10'
10'
6'
10'
10'
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way,
Canton, MA 02021-1407 • (781) 821-8370 • Web Site:
Desco.com
TB-2000
Page 3 of 4
© 2015 DESCO INDUSTRIES INC.
Employee Owned
6. The
09813
/
09814
mat ground cord may be either attached to
a mat by snapping onto a 10mm socket, or by bolting it to the
mat with the hardware supplied with the cord. When bolting
the
09814
to the mat use a 3/8" diameter hole punch to create
the hole for mounting. This will allow cord to sit flush on the
mat. Note: For both applications, remove screw from floor mat
ground before attaching to mat.
7. If you are using a mat kit that includes the wrist strap, install
the wrist strap directly to the common point mat ground cord
banana jack. Again, test the resistance from the backplate of
the wrist strap to the common ground point. It should read 1
Megohm ± 20 percent.
09825
/
09826
Figure 15. Adding the wriststrap.
Figure 13. Installing
09814
to mat using supplied hardware.
BE SURE YOU TEST ALL GROUNDS AND THE WRIST STRAP
FREQUENTLY.
The following bulletins are available from Desco:
TB-2004
Operation of
19350
Wrist Strap Tester
TB-2005
Wrist Straps, Grounding, Testing, Maintenance
TB-2007
Safe Grounding of Static Controlled Workstations
Mat Installation - General Information
1. For best results, allow the mats to lay flat for about four
hours at room temperature before installing. This will give the
material time to flatten out from being rolled for shipment.
2. Test grounds for proper resistance to ground. See Desco
Technical Bulletin
TB-2007
for a complete discussion of
grounds.
3. Lay the mat in position and snap the ground cord to it. Bring
the other end of the ground cord to the common ground point
and attach it using the ring terminal. A suggested ground point
is the center screw of a standard AC electrical outlet. Testing is
recommended to ensure that the screw is properly grounded.
Tie the ground wire to the bench to keep it out of the way and
neat. You may cut and strip the ground wire to a shorter length
and attach it with the extra ring terminal included with each
Desco ground cord.
Maintenance and Cleaning
For optimum performance, periodic cleaning is required following
manufacturer’s recommendations. Desco recommends
Reztore™
Surface and Mat Cleaner
for workstation mats and other surfaces
and
Statguard® Floor Mat Cleaner
for floor mats.
Note: Desco’s Reztore™ Surface and Statguard® Floor Mat
Cleaners contain no silicone or harsh solvents. Cleaners with
silicone leave an insulative residue on surfaces and solvents such
as 2-Butoxyethanol or Ethanolamine used in cleaners can dry out
the material; both can prevent conductive or dissipative mats from
functioning properly.
Limited Warranty, Warranty Exclusions, Limit of Liability
and RMA Request Instructions
“GREEN WIRE”
UTILITY
GROUND
POINTS
RING
TERMINAL
CAN BE
ATTACHED
HERE
See Desco’s Terms and Conditions -
http://desco.descoindustries.com/TermsAndConditions.aspx
Figure 14. Hooking up ground cords.
4. If your installation includes a floor mat, you should duplicate
step 2 and attach the floor mat ground to the same point as the
worksurface ground wire.
5. Measure the resistance from the ground snap on the mat to
the common ground point. It should read 1 megohm ± 20
percent if you are using a ground cord with a resistor, and less
than 1 ohm if you are using a non-resistor ground cord.
6. Using a surface resistance tester per ESD TR53, test the
resistance to ground from the center of the mat surface.
Required equipment: a megohmmeter with 100 volt open test
circuit voltage and two five pound electrodes per ASTM-150.
Desco sells this as the Digital Surface Resistance Meter
Kit, item
19787.
For more information on the
19787,
ask for
Technical Bulletin
TB-3062.
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way,
Canton, MA 02021-1407 • (781) 821-8370 • Web Site:
Desco.com
TB-2000
Page 4 of 4
© 2015 DESCO INDUSTRIES INC.
Employee Owned
