Laird-Signal-Laird-Tech-8863-LT20NE2192

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Elastomeric

EMI Shielding

S O L U T I O N S

ABOUT

LAIRD

Laird designs and manufactures customized, performance-criꢀcal products

for wireless and other advanced electronics applicaꢀons.

The company is a global market leader in the design and supply of

electromagneꢀc interference (EMI) shielding, thermal management

products, mechanical actuaꢀon systems, signal integrity components, and

wireless antennae soluꢀons, as well as radio frequency (RF) modules and

systems.

Laird is the world leader in the design and manufacture of customized,

performance-criꢀcal products for wireless and other advanced electronics

applicaꢀons. Laird partners with its customers to customize product

soluꢀons for applicaꢀons in many industries including:

• Network Equipment

• Handsets

• Aerospace

• Defense

• Telecommunicaꢀons

• Medical Equipment

• Data Transfer & Informaꢀon Technology

• Consumer Electronics

• Computers

• Industrial

• Automoꢀve Electronics

Laird oﬀers its customers unique product soluꢀons, dedicaꢀon to research

and development, as well as a seamless network of manufacturing and

customer support faciliꢀes across the globe.

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

TABLE OF

CONTENTS

VISUAL PART REFERENCE GUIDE

PART NUMBER CROSS REFERENCE

GEMINI™ COEXTRUSIONS

ELECTROSEAL CONDUCTIVE

ELASTOMER FABRICATED COMPONENTS

Overview

INTRODUCTION TO

Molded EMI O-Rings

Flat Washer Gaskets

Molded Waveguide Gaskets

Rectangular Waveguide Gaskets

ELECTRICALLY CONDUCTIVE ELASTOMERS

Overview

Material Selecꢀon Guide

EMI Gasket Mounꢀng Techniques

AUTOMATED FORM-IN-PLACE

EMI Gasket Technologies Introducꢀon

Material Speciﬁcaꢀons

ELECTROSEAL™ CONDUCTIVE

ELASTOMER MATERIAL

ElectroSeal Conducꢀve Elastomer EMI Shielding

ELECTROSEAL CONDUCTIVE

ELASTOMER EXTRUSIONS

MOLD-IN-PLACE PRINTED

CIRCUIT BOARD SHIELDING

Rectangular Strips

Hollow Rectangular Strips

Hollow D-Strips

O-Strip Tubing

D-Strips

SPECIALTY PRODUCTS

ElectroCoat™

Board to Chassis Conducꢀve Stand-Oﬀ

Corrosion of EMI Gaskets

Channel Strips

O-Strips

ELASTOMER GALVANIC

COMPATIBILITY CHART

Metal Coupon Weight Loss Raꢀng

P-Strips

All parts listed in this catalog are lead free and RoHS

compliant.

This catalog contains a limited selecꢀon of Laird products.

Refer to www.lairdtech.com for other products not

included in this catalog.

Noꢀce:

Information on the products described in this catalog is based on laboratory test data which Laird believes to be reliable. However, Laird has no control over the design of actual

products which incorporate Laird’ products or actual fabrication of devices using Laird’ products. Accordingly, Laird cannot guarantee that the same test data as described

herein will be obtained. Thus, it is recommended that each user make their own tests to confirm laboratory test data and determine suitability of Laird’ products for their

particular application.

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ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION

From concept to compliance,

over 30 years of elastomer experience

Electrically conducꢀve elastomers provide environmental sealing, and excellent mechanical and

electromagneꢀc shielding properꢀes. They are ideal for applicaꢀons that demand both environmental sealing

and EMI shielding, and can be used in a wide range of operaꢀng temperatures. Laird oﬀers a wide variety of

conducꢀve ﬁller materials in extruded, molded die-cut,dispensed form-in-place, printed and coated formats.

We are constantly formulaꢀng new and custom compounds to provide you with more design opꢀons to meet

your needs.

•

ꢁExtrusion presses produce a mulꢀtude of conducꢀve elastomer proﬁles in diﬀerent compounds which are

used in both military and commercial applicaꢀons.

•

ꢁComputerized mulꢀ axis form-in-place dispensing machines deposit conducꢀve elastomer compounds

onto miniaturized thin wall mulꢀ-compartment housing covers.

•

ꢁMolding of EcE compounds is controlled from design through fabricaꢀon, from single cavity prototype to

mulꢀ-cavity producꢀon or compression type molds.

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ELECTROSEAL CONDUCTIVE ELASTOMER

VISUAL PART REFERENCE

UIDE

ELECTROSEAL CONDUCTIVE ELASTOMERS

Rectangular Strips

Page 15

Hollow Rectangular Strips

Page 15

Hollow D-Strips

Page 16

O-StripTubing

Page 17

D-Strips

Page 18

Channel Strips

Page 18

O-Strips

Page 19

P-Strip Tubing

Page 20

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

ELECTROMET METAL IMPREGNATED

MATERIALS – STRIPS / SHEETS

Page 23

Page 33

FORMꢂINꢂPLACE EMI

DISPENSED GASKETS

BOARD TO CHASSIS

CONDUCTIVE STANDꢂOFF

ELECTROCOAT

Page 30

Page 34

Page 35

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ELECTROSEAL CONDUCTIVE ELASTOMER

PART NUMBER

ROSS REFERENCE

PART NUMBER

DESCRIPTION

PAGE

8550-XXXX-XX

8560-XXXX-XX

8563-XXXX-XX

8569-0127-XX

8569-0131-XX

8860-XXXX-XXX-XX

8861-XXXX-XX

8862-XXXX-XX

8863-XXXX-XX

8864-XXXX-XX

8865-XXXX-XX

889X-XXXX-XX

8408-01XX-XX

8408-02XX-XX

Electrocoat

Flat Washer Type Gaskets

Rectangular Waveguide Gaskets

Molded Emi O-Rings

Page 41

Page 26

Page 28

Pages 24, 25

Page 27

Page 35

Page 14

Page 15

Page 19

Page 17

Page 18

Page 21

Page 33

Page 10, 11

Page 32

Molded Waveguide Gaskets- Circular “D”

Molded Waveguide Gaskets- Rectangular “D”

Molded Waveguide Gaskets- Rectangular “O”

Board To Chassis Conducꢀve Stand-Oﬀ

Electroseal Conducꢀve Elastomer Sheet

Electroseal Rectangular Strips

Electroseal Hollow Rectangular Strips

Electroseal O-Strips

Electroseal O-Strip Tubing

Electroseal D-Strips

GEMI Coextrusions

Electromet Metal Impregnated Materials – Strips

Electromet Metal Impregnated Materials – Sheets

ECE Material Selecꢀon Guide

FIP Paste Selecꢀon Guide

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ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION TO ELECTRICALLY

CONDUCTIVE ELASTOMERS

OVERVIEW

ELECTROSEAL™ GASKET INTRODUCTION

Conducꢀve elastomer gaskets are EMI shielding

and sealing devices made from highly conducꢀve,

mechanically resilient and conformable vulcanized

elastomers. They are available in the following types:

The electrically conducꢀve elastomers are based on

dispersed parꢀcles in elastomers, oriented wire in solid

or sponge elastomers, impregnated wire mesh screens

or expanded metals. They provide highly conducꢀve, yet

resilient gaskeꢀng materials for EMI sealing as well as

pressure and environmental sealing.

Flat gaskets or die-cuts

Molded shapes such as O-rings or intricate parts

Extruded proﬁles or strips

Vulcanized-to-metal covers or ﬂanges

Co-molded or reinforced seals

Form-in-place gaskets

Conducꢀve elastomers are used for shielding electronic

enclosures against electromagneꢀc interference (EMI).

Usually, the shielding system consists of a conducꢀve

gasket sandwiched between a metal housing and lid.

The primary funcꢀon of these gaskets is to provide

suﬃcient electrical conducꢀvity across the enclosure/

gasket/lid juncꢀon to meet grounding and EMI shielding

requirements, as well as prevent intrusion of the ﬂuids

into the electrical components.

When any two ﬂat, but rigid surfaces are brought

together, slight surface irregulariꢀes on each surface

prevent them from meeꢀng completely at all points.

These irregulariꢀes may be extremely minute, yet may

provide a leakage path for gas or liquid under pressure,

and for high frequency electromagneꢀc energy. This

problem remains in ﬂange sealing even when very high

closure force is applied.

Laird oﬀers conducꢀve elastomers in the

following forms:

ElectroSeal dispersed ﬁller parꢀcles in elastomers

ElectroMet oriented wire in solid and sponge

elastomers, and impregnated wire mesh and

expanded metals

However, when a gasket fabricated of resilient material is

installed between the maꢀng surfaces, and even minimal

closure pressure is applied, the resilient gasket conforms

to the irregulariꢀes in both maꢀng surfaces. As a result,

all surface imperfecꢀons and potenꢀal leak paths across

the joint area are sealed completely against pneumaꢀc

and ﬂuid pressure or penetraꢀon by environmental

gases. If the gasket is conducꢀve as well as resilient, with

conducꢀve matrix distributed throughout its total volume

in mesh or parꢀcle form, the joint can be addiꢀonally

sealed against penetraꢀon by, or exit of, electromagneꢀc

energy.

DESIGN CONSIDERATIONS

The design requirements of the installaꢀon will usually

narrow the choice considerably, parꢀcularly if the basic

geometry of the enclosure is already established, or

if military EMI shielding speciﬁcaꢀons are involved. In

addiꢀon to choices of size and shape dictated by the

enclosing structure and the joint geometry itself, the

following four factors greatly inﬂuence the suitability of

EMI gasket materials: shielding eﬀecꢀveness, closure

force, percent gland ﬁll and compression/deﬂecꢀon.

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CLOSURE FORCE REQUIREMENTS

GUIDELINES FOR GROOVE DIMENSIONS:

As a general rule we recommend a gland ﬁll of 85% ꢅ 95%

for opꢀmum shielding eﬀecꢀveness. However, for criꢀcal

applicaꢀons that require both shielding and environmental

sealing, a 95% gland ﬁll is suggested. For applicaꢀons that

require special design, please contact Laird applicaꢀons

engineering staﬀ.

Solid conducꢀve elastomer materials such as ElectroSeal

stand up beꢃer to high closure forces, environmental

pressures, and repeated opening and closing of the joint.

Unlike sponge elastomers, solid conducꢀve elastomers do

not actually compress. They accommodate pressures by

changing shape, rather than volume. This is an important

diﬀerence in ﬂange joint design requirements between the

two material types, since addiꢀonal gland volume must be

allowed for the potenꢀal expansion of the elastomer under

heat and/or pressure. Greater ﬂange strength must oꢄen be

provided to allow for increased closure force requirements.

If low closure force is a consideraꢀon, however, the

use of hollow extruded proﬁles such as the ElectroSeal

hollow “O” and hollow “D” in conjuncꢀon with soꢄer

durometer elastomers will dramaꢀcally reduce closure force

requirements.

Recommended groove dimensions are provided on pages

18-19 for the solid D and solid O extruded proﬁles.

COMPRESSION/DEFLECTION

Compression/deﬂecꢀon data provide the engineer or

designer with a qualitaꢀve comparison of the deformability

of diﬀerent proﬁles of conducꢀve elastomers. Deﬂecꢀon

is deﬁned as the change in the cross-secꢀonal height of a

gasket under compressive load and is a funcꢀon of material

hardness and proﬁle. The recommended deﬂecꢀon ranges

of various conducꢀve elastomer proﬁles are shown in

Table 1. In no case however, should the amount of actual

deﬂecꢀon be less than 10% for ElectroSeal materials.

Remember that the minimum unevenness of the maꢀng

ﬂanges must be taken into consideraꢀon in determining the

original (uncompressed) and installed (compressed) height

of the seal. Note that wall thickness of hollow proﬁles has a

major eﬀect on deﬂecꢀon

PERCENT GLAND FILL (VOLUME/VOID RATIO)

Design of an elastomeric O-ring gland, or groove and

contacꢀng surfaces which make up the seal assembly,

is as important as percent gland ﬁll. For most staꢀc seal

applicaꢀons, it is necessary to calculate the area of the

seal and the gland it will occupy, to determine whether the

laꢃer is large enough to receive the ring. Always try to avoid

designs that stretch the elastomer more than 5%. If the seal

element is stretched or compressed more than one or two

percent, calculaꢀon based on the volume should be used

unless volume swell is a facto

rrespecꢀve of whether the

calculaꢀons are based on volumes or cross-secꢀonal areas,

it is important to compare the largest possible seal cross-

secꢀonal area with the smallest gland, taking all tolerances

into consideraꢀon. Never allow groove and seal tolerances

to create an “overﬁlled” groove condiꢀon. Suﬃcient volume

must be provided within the groove area to provide for a

90% to 95% gland ﬁll. Figure 1 shows underﬁlled, overﬁlled,

and opꢀmum ﬁlled grooves.

TABLE 1.

RECOMMENDED DEFLECTION FOR ELECTROSEAL PROFILES

CROSS SECTION SHAPE

Flat Strip

DEFLECTION

5-10 Percent

20-25 Percent

15-20 Percent

20-50 Percent

25-50 Percent

15-25 Percent

Solid O

Solid D

Hollow O

Hollow D

Hollow P

Interference Fit

Note: Selecꢀon of a proper proﬁle has a bearing on the design

and the performance of an EMI gasket.

FIGURE 1. GROOVE FILL LEVELS

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ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION TO ELECTRICALLY

CONDUCTIVE ELASTOMERS

The temperature capabiliꢀes of various ElectroSeal

elastomers are shown in Table 2.

SERVICE LIFE

Three fundamental factors are involved when considering

the service life of an EMI gasket:

TABLE 2.

TEMPERATURE CAPABILITIES OF

PRINCIPAL ELECTROSEAL ELASTOMERS

The presence of detrimental chemicals and ﬂuids,

ozone aging and temperature extremes.

LOW

ELASTOMER TYPE

UPPER

TEMPERATURE

The number of ꢀmes the joint will be opened and

closed during the projected operaꢀng life of the

equipment.

EPDM

-58°F (-50°C)

-49°F (-45°C)

-67°F (-55°C)

257°F (125°C)

392°F (200°C)

347°F (175°C)

Silicone

Fluorosilicone

Potenꢀal exposure to inadvertent damage during

iniꢀal installaꢀon and future maintenance.

AGING/SHELF LIFE

Another major factor in the selecꢀon of any elastomer

desꢀned for sealing/shielding service is ꢀme, or more

properly, seal life. The expected life of a seal may involve

only a few seconds in the case of some highly specialized

seals used in solid propellant rocket casings, to as much

as 10 to 20 years and beyond in the case of seals used in

deep-space vehicles.

ENVIRONMENTAL CONSIDERATIONS

Proper material selecꢀon for eﬀecꢀve EMI shielding

depends on the total environmental envelope within

which the seal/shield will be expected to funcꢀon. The

material selecꢀon process should begin with a careful

analysis of the following major environmental condiꢀons:

•

Temperature

Aging/Shelf Life

Pressure/Vacuum

•

Fluid Compaꢀbility

Galvanic Compaꢀbility

Deterioraꢀon with ꢀme or aging relates to the type of

polymer and storage condiꢀons. Exposure may cause

deterioraꢀon of elastomers whether installed or in storage.

Resistance to deterioraꢀon in storage varies greatly

between the elastomers. Military Handbook 695 (MIL-

HDBK-695) divides syntheꢀc elastomers in the following

groups according to age resistance as shown in Table 3.

TEMPERATURE

Temperature, though seemingly elementary, is oꢄen

the most misunderstood and exaggerated of all sealing

environment parameters; hence, it is all too oꢄen over-

speciﬁed.

TABLE 3.

Low Temperature

AGE RESISTANCE OF PRINCIPAL ELECTROSEAL ELASTOMERS

Low temperature induced changes in the elastomer

properꢀes are generally physical in nature. As the

temperature decreases below allowable limits, the

elastomeric properꢀes are lost and the material becomes

very hard and briꢃle. Duraꢀon of the eﬀects of low

temperature exposure is not signiﬁcant and the original

properꢀes are regained upon resumpꢀon of moderate

temperatures.

ASTM

SHELF LIFE

BASE POLYMER

DESIGNATION

ꢆYEARSꢇ

Ethylene Propylene

Diene Monomer

EPDM

5 to 10 Years

Silicone MQ, VMQ,

Fluorosilicone

PVMQ

FVMQ

Up to 20 Years

PRESSURE VACUUM

Conducꢀve elastomer seals are rarely used for high-pressure

systems, with the excepꢀon of waveguide seals. Pressure

has a bearing on the choice of material and hardness. Low

durometer materials are used for low pressure applicaꢀons,

whereas high pressure may require a combinaꢀon of

material hardness and design.

High Temperature

High temperatures also aﬀect the properꢀes of

elastomers in the same way as the low temperatures. As

the temperature begins to rise, the elastomer will soꢄen,

lowering its extrusion resistance. Tensile strength and

modulus also decrease under high temperatures, and

elongaꢀon is increased. But these iniꢀal changes reverse

if exposure to high temperatures is brief. Changes due

to prolonged high temperature exposure are chemical in

nature rather than physical, and are not reversible.

Outgassing and/or sublimaꢀon in a high vacuum system

can cause seal shrinkage (loss of volume), resulꢀng in a

possible loss of sealing ability. When properly designed

and conﬁned, an O-ring, molded shape, or a molded-to-

the-cover plate seal can provide adequate environmental

sealing as well as EMI shielding for vacuum (to 1 x 10-6

Torr) applicaꢀons.

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FLUID COMPATIBILITY

GALVANIC COMPATIBILITY

The primary funcꢀon of elastomeric EMI seals is to provide

suﬃcient electrical conducꢀvity across the enclosure/port/

ﬂange juncꢀon, while at the same ꢀme provide at least

minimal environmental sealing capability. Consideraꢀon

must be given to the basic compaꢀbility between the

elastomer seal/shield element and any ﬂuids with which

it may come in prolonged contact. Table 4 lists the general

reacꢀon to common ﬂuid media for the polymer types

commonly used in ElectroSeal conducꢀve elastomers.

Note that any proposed conducꢀve material and design

should be thoroughly tested by the user under all possible

condiꢀons prior to producꢀon.

Compaꢀbility between the gasket and the maꢀng ﬂanges is

another area which must be given proper aꢃenꢀon when

designing a gasket for sealing/shielding. This problem can

be minimized by various means, the simplest and most

eﬀecꢀve of which is proper gasket and ﬂange design. This

must be coupled with the judicious selecꢀon of a gasket

material compaꢀble with the maꢀng surfaces. A large

diﬀerence in corrosion potenꢀal between the maꢀng

surface and the conducꢀve elastomer and the presence

of a conducꢀve electrolyte, such as salt water or a humid

environment, will accelerate galvanic corrosion.

Under dry condiꢀons, such as the typical oﬃce

The complex chemistry involved in the combinaꢀon of the

polymer and metallic ﬁllers in conducꢀve elastomers makes

it imperaꢀve that such tests be conducted to determine

suitability for use with a given ﬂuid.

environment, there will be liꢃle danger of galvanic

corrosion. However, when the gasket is exposed to high

humidity or salt-water environments, galvanic corrosion will

occur between dissimilar metals. The likelihood of galvanic

corrosion increases as the potenꢀal diﬀerence between

the maꢀng surface and the elastomer increases. The

charts on pages 47-48 indicate which maꢀng surfaces and

elastomer combinaꢀons minimize the corrosion potenꢀal.

In addiꢀon, the less permeable elastomers, such as EPDM

and ﬂuorosilicone, limit galvanic corrosion by restricꢀng

the access of the electrolyte to the conducꢀve ﬁllers in

the gasket. For further details on galvanic corrosion of

elastomeric materials, see pages 43-48.

TABLE 4.

RESISTANCE OF PRINCIPAL ELECTROSEAL ELASTOMERS

TO FLUIDS

FLUID

SILICONE

FLUOROSILICONE

EPDM

Good

Impermeability to

Gases

Poor

Fair

Ozone and

Excellent

Fair

Excellent

Good

Fair

Excellent

Ultraviolet

Don’t

use

ASTM 1 Oil

Hydraulic Fluids

(Organic)

Hydraulic Fluids

(Phosphate ester)

Don’t

use

Fair

Excellent

Don’t

Hydrocarbon Fuels

Dilute Acids

Don’t use

Fair

Good

use

Good

Fair/

Good

Concentrated Acids

Don’t use

Dilute Bases

Fair

Good

Excellent

Good

Concentrated Bases

Esters/Ketones

Don’t use

Excellent

(Decontaminaꢀng

Fluid)

Poor

Good

STB

(Decontaminaꢀng

Fluid)

Good

Low Temperature

High Temperature

Compression Set

Radiaꢀon Resistance

Excellent

Good

Excellent

Good

Excellent

Good

Poor

Good

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ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION TO ELECTRICALLY

CONDUCTIVE ELASTOMERS

MATERIAL SELECTION GUIDE

Laird oﬀers a series of products to meet a wide range of customer requirements for military and

commercial applicaꢀons. The classiﬁcaꢀons of the most common materials are based on cost and

speciﬁc applicaꢀons and are outlined in Table 5.

TABLE 5

PARAMETER

TEST METHOD

ECE Name

ECE93

Ni/C

ECE72

Ni/C

ECE92

Ni/C

ECE115

ECE125

ECE85A

ECE116

ECE126

ECE118

ECE88

Ag/Cu

MIL-DTL-83528C Material Type

Type M

Type B

Type D

Type A

Filler

Ag/Glass

Ag/Al

Ag/Cu

Elastomer

Color

Silicone Silicone

Fluorosilicone

Silicone

Fluorosilicone

Silicone

Fuorosilicone

Silicone

Fluorosilicone

Black

Gray

Dark Gray

Tan

Electrical Properꢀes

Volume Resisꢀvity,

Ω cm, max

MIL-DTL-83528C

0.1

0.006

100

0.01

0.004

100

0.008

100

0.01

100

0.004

120

0.01

110

para 4.5.10

Shielding Eﬀ, 10 GHz,

dB, min

MIL-DTL-83528C

para 4.5.12

100

Physical Properꢀes

Density, g/cm3 (±0.25)

Hardness, Shore A (±7)

Tensile Strength, psi, min

Elongaꢀon

ASTM D792

ASTM D2240

ASTM D412

1.9

2.3

2.2

1.9

3.3

4.1

150

280

150

200

60-200%

200

60%

200

450

180

ASTM D412

100-300% 150%

60-250%

100-300%

60-260%

100-300%

Tear Strength, ppi, min

Compression Set, max

ASTM D624, die C

ASTM D395

30%

3.5

30%

32%

3.5

30%

3.5

32%

3.5

35%

3.5

Compression /

Deﬂecꢀon, %, min

ASTM D575

Max Ope

. T

mp., °C

MIL-DTL-83528C

para 4.5.15

160

150

160

125

Min. Ope

. T

mp., °C

Flame Retardance

Fluid Immersion

ASTM D1329

UL 94

-55

–

-55

–

-55

-50

-45

-55

–

-55

–

-55

–

MIL-DTL-83528C

para 4.5.17

N/S

SUR

N/S

SUR

Electrical Stability

Aꢄer Heat Aging,

Ω cm, max

MIL-DTL-83528C

para 4.5.15

0.2

0.1

–

0.2

0.1

0.015

0.009

0.015

–

0.01

0.015

0.01

0.015

0.01

0.008

0.006

0.01

0.015

Aꢄer Break,

Ω cm, max

MIL-DTL-83528C

para 4.5.9

During Vibraꢀon,

Ω cm, max

MIL-DTL-83528C

para 4.5.13

Aꢄer Exposure to EM

Ω cm, max

MIL-DTL-83528C

para 4.5.16

Manufacturing Processes

Molded sheet / diecut parts

Molded shapes / O-rings

Extruded proﬁles

Notes:

N/S = Not Survivable

SUR = Survivable

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ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION TO ELECTRICALLY

CONDUCTIVE ELASTOMERS

PARAMETER

EcE Name

ECE82

ECE83

ECE84

ECE90

ECE87

ECE13

ECE95

ECE96

Ag/Al

ECE89

Ag/Al

MIL-DTL-83528C Material Type

Type E

Type J

Filler

Ag/Ni

Silicone

Tan

Ag/Ni

Fluorosilicone

Tan

Ni/C

EPDM

Black

Elastomer

Color

Silicone

Beige

Silicone

Beige

Silicone

Black

EPDM

Black

EPDM

Fluorosilicone

Tan

Blue

Electrical Properꢀes

Volume Resisꢀvity,

Ω cm, max

0.002

120

0.01

0.005

100

0.005

100

0.15

0.01

0.012

100

Shielding Eﬀ, 10 GHz,

dB, min

Physical Properꢀes

Density, g/cm3 (±0.25)

Hardness, Shore A (±7)

Tensile Strength, psi, min

Elongaꢀon

3.5

1.8

4.1

1.3

1.2

2.2

300

150

200

300

700

2000

200

180

100-300%

50-250%

100-300%

100-300% 100-400% 70-260%

70-260%

60-260%

Tear Strength, ppi, min

Compression Set, max

45%

3.5

100

30%

40%

50%

45%

2.5

35%

32%

3.5

25%

30%

3.5

Compression /

Deﬂecꢀon, %, min

Max Ope

. T

mp., °C

160

125

160

125

160

Min. Ope

. T

mp., °C

Flame Retardance

Fluid Immersion

-55

–

-55

–

-55

–

-50

–

-55

–

-40

–

-40

–

-40

–

-55

–

N/S

SUR

N/S

SUR

Electrical Stability

Aꢄer Heat Aging,

Ω cm, max

0.01

0.015

0.02

0.01

–

0.015

Aꢄer Break,

Ω cm, max

During Vibraꢀon,

Ω cm, max

0.015

–

Aꢄer Exposure to EM

Ω cm, max

–

Manufacturing Processes

Molded sheet / diecut parts

Molded shapes / O-rings

Extruded proﬁles

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

INTRODUCTION TO ELECTRICALLY

CONDUCTIVE ELASTOMERS

EMI GASKET MOUNTING TECHNIQUES

Common EMI gasket mounꢀng techniques are:

INTERFERENCE FIT APPLICATIONS

Allow 0.005 in. (0,1 mm) to 0.100 in. (2,5 mm)

POSITIONING IN A GROOVE

interference for part to hold and eliminate the need for

This is a highly recommended method if a suitable groove

adhesive. Groove depth should be set to ensure that the

can be provided at a relaꢀvely low cost. Placing the EMI

channel is not over-ﬁlled.

gasket in such a groove provides several advantages:

WATER TIGHT APPLICATIONS

metal-to-metal contact of maꢀng ﬂange surfaces

Fill channel with as much material as possible, taking

provides a compression stop and prevents

tolerances into account. Use cauꢀon to avoid overﬁll

overcompression of the gasket material;

condiꢀons.

is cost-eﬀecꢀve by reducing assembly ꢀme;

best overall seal for EMI, EM

alt fog, NBC, and

BONDING WITH ADHESIVES

ﬂuids by providing metal-to-metal ﬂange contact and

reducing exposure of the seal element to aꢃack by

outside elements.

The EMI gasket may be aꢃached to one of the maꢀng

ﬂanges by the applicaꢀon of pressure sensiꢀve or

permanent adhesives. A suitable conducꢀve adhesive

is always preferable over a nonconducꢀve adhesive for

mounꢀng EMI gaskets as they can provide adequate

electrical contact between the EMI gasket and the

mounꢀng surface.

FIGURE 2

BOLT-THROUGH HOLES

This is a common and inexpensive way to hold an

EMI gasket in posiꢀon. Locator bolt holes can be

accommodated in the tab or in rectangular ﬂat gaskets as

shown in Figure 3.

FIGURE 3

www.lairdtech.com

INTERFERENCE FIT

VULCANIZED MOUNTING

For applicaꢀons such as face seals or where the gasket must

be retained in the groove during assembly, interference ﬁt

is an excellent and inexpensive choice. The gasket is simply

held in the groove or against a shoulder by mechanical

fricꢀon as shown in Figure 4.

In this case, the seal element is vulcanized directly to

the metal ﬂange or cover under heat and pressure. The

vulcanized to the-metal mounꢀng oﬀers a homogeneous

one-piece gasket with superior conducꢀvity between the

gasket and the metal.

Laird provides EMI seals bonded to covers and retainers.

Such devices may have the conducꢀve element bonded in

a groove or vulcanized to the edge of a thin sheet metal

retaine

igure 5 shows a vulcanized mounted and frame

mounted gasket.

FIGURE 4

FIGURE 5

FRICTION, ABRASION AND

IMPACT CONSIDERATIONS

The physical posiꢀoning of EMI gaskets in an environment

where fricꢀon, abrasion and impact are possible needs

special consideraꢀon. EMI gaskets in such an environment

should be posiꢀoned so that they receive liꢃle or no sliding

or side-to-side moꢀon when being compressed. Examples of

common aꢃachments for access door gaskets are shown in

Figure 6.

MOUNTING TIPS

Care should be taken to avoid excess handling of conducꢀve

elastomers, including excessive stretching, bending or

exposure to grease.

FIGURE 6 COVER WITH COMPRESSION STOP

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

ELECTROSEAL CONDUCTIVE

ELASTOMER

ATERIAL

SHEET MATERIAL

Table 1 lists thicknesses and sizes for our molded

sheet material, while Table 2, pages 10-11, shows the

compounds available for all of our conducꢀve silicone

elastomers.

HOW TO SPECIFY ECE

Decide on molded sheet stock or extruded shapes. Select

the desired conﬁguraꢀon and dimensions from Table 1

(for sheet stock) or Figures 1ꢅ8 (for extruded shapes).

Select the desired material from Table 2. Insert material

number from Table 2, |pages 14ꢅ17, in place of the leꢃers

XX in the Laird part numbe

Example

From Figure 1, on page 18, for a rectangular strip

measuring 0.500 in. (12,7 mm) x 0.075 in. (1,9 mm),

part number is 8861-0130-XX.

From Table 2, on page 16, for silver-nickel ﬁller, material

number is 84.

ELECTROSEAL™ CONDUCTIVE

ELASTOMER EMI SHIELDING

Ordering part number is 8861-0130-84.*

Laird electrically conducꢀve elastomer products are

ideal for both military and commercial applicaꢀons

requiring both environmental sealing and EMI shielding.

Compounds can be supplied in molded or extruded

shapes, sheet stock, custom extruded, or die-cut shapes

to meet a wide variety of applicaꢀons.

Note: Rectangular and D-shaped extrusions can be

supplied with pressure sensiꢀve adhesive tape.

Our conducꢀve extrusions oﬀer a wide choice of proﬁles

to ﬁt a large range of applicaꢀons. The cross-secꢀons

shown on the following pages are oﬀered as standard.

Custom dies can be built to accommodate your speciﬁc

design.

•

Available in a wide variety of conducꢀve

ﬁller materials

•

Shielding eﬀecꢀveness up to 120 dB at 10 GHz

THICKNESS

0.020 (0,5)

0.032 (0,8)

0.045 (1,1)

0.062 (1,5)

0.093 (2,3)

0.100 (2,5)

0.125 (3,2)

10 X 10 SHEET

10 X 15 SHEET

15 X 20 SHEET

18 X 18 SHEET

N/A

8860-0020-100-XX

8860-0032-100-XX

8860-0045-100-XX

8860-0062-100-XX

8860-0093-100-XX

8860-0100-100-XX

8860-0125-100-XX

8860-0020-150-XX

8860-0032-150-XX

8860-0045-150-XX

8860-0062-150-XX

8860-0093-150-XX

8860-0100-150-XX

8860-0125-150-XX

8860-0020-300-XX

8860-0032-300-XX

8860-0045-300-XX

8860-0062-300-XX

8860-0093-300-XX

8860-0100-300-XX

8860-0125-300-XX

8860-0032-324-XX

8860-0045-324-XX

8860-0062-324-XX

8860-0093-324-XX

8860-0100-324-XX

8860-0125-324-XX

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

Rectangular Strips

Hollow Rectangular Strips

NOMINAL DIMENSIONS

NOMINAL DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ85328

PART

PART NUMBER

INCHꢆMMꢇ

PART NUMBER

NUMBER

8862-0112

8862-0113

8862-0114

8862-0100

8862-0105

0.125 (3,2)

0.200 (5,1)

0.250 (6,4)

0.330 (8,4)

0.375 (9,5)

0.125 (3,2)

0.130 (3,3)

0.250 (6,4)

0.305 (7,7)

0.375 (9,5)

0.078 (2,0)

0.090 (2,3)

0.156 (4,0)

0.125 (3,2)

0.188 (4,8)

M83528/009X001

8861-0100

8861-0179

8861-0181

8861-0105

8861-0110

8861-0115

8861-0120

8861-0121

8861-0167

8861-0193

8861-0125

8861-0173

8861-0174

8861-0136

8861-0175

8861-0183

0.063 (1,6)

0.079 (2,0)

0.095 (2,4)

0.120 (3,0)

0.125 (3,2)

0.156 (4,0)

0.187 (4,8)

0.188 (4,8)

0.189 (4,8)

0.250 (6,4)

0.252 (6,4)

0.378 (9,6)

0.042 (1,1)

0.039 (1,0)

0.059 (1,5)

0.062 (1,6)

0.075 (1,9)

0.062 (1,6)

0.125 (3,2)

0.062 (1,6)

0.189 (4,8)

0.062 (1,6)

0.125 (3,2)

0.188 (4,8)

0.200 (5,1)

0.031 (0,8)

0.063 (1,6)

0.020 (0,5)

0.042 (1,1)

0.059 (1,5)

0.075 (1,9)

0.094 (2,4)

0.125 (3,2)

0.188 (4,8)

0.040 (1,0)

0.042 (1,1)

0.062 (1,6)

0.071 (1,8)

0.094 (2,4)

0.062 (1,6)

0.043 (1,1)

0.062 (1,6)

0.126 (3,2)

0.250 (6,4)

0.062 (1,6)

M83528/009X002

M83528/009X003

M83528/009X004

M83528/009X005

M83528/002X006

8861-0172 0.500

(12,7)

8861-0131 0.500

(12,7)

8861-0182 0.500

(12,7)

8861-0130 0.500

(12,7)

8861-0188 0.500

(12,7)

8861-0135 0.500

(12,7)

8861-0140 0.500

(12,7)

8861-0142 0.750

(19,1)

8861-0141 0.750

(19,1)

8861-0145 0.750

(19,1)

8861-0184 0.827

(21,0)

8861-0189 0.827

(21,0)

8861-0150 0.880

(22,4)

8861-0103 0.984

(25,0)

M83528/009X007

M83528/009X008

M83528/009X009

M83528/009X010

M83528/009X011

8861-0169

8861-0192

8861-0155

8861-0160

1.00 (25,4)

1.18 (30,0)

M83528/009X012

M83528/009X013

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

Hollow D-Strips

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

RAD

VIEW

8866-0135

8866-0160

8866-0130

8866-0162

8866-0100

8866-0111

8866-0103

8866-0136

8866-0105

8866-0131

8866-0050

8866-0110

8866-0120

8866-0116

8866-0127

8866-0168

8866-0166

8866-0134

8866-0137

8866-0169

8866-0126

8866-0125

8866-0148

8866-0139

8866-0129

8866-0155

0.093 (2,4)

0.098 (2,5)

0.100 (2,5)

0.109 (2,8)

0.156 (4,0)

0.158 (4,0)

0.160 (4,1)

0.187 (4,8)

0.250 (6,4)

0.312 (7,9)

0.325 (8,3)

0.358 (9,1)

0.374 (9,5)

0.375 (9,5)

0.093 (2,4)

0.098 (2,5)

0.094 (2,4)

0.125 (3,2)

0.156 (4,0)

0.240 (6,1)

0.120 (3,0)

0.187 (4,8)

0.145 (3,7)

0.250 (6,4)

0.312 (7,9)

0.575 (14,6)

0.374 (9,5)

0.252 (6,4)

0.250 (6,4)

0.046 (1,2)

0.049 (1,2)

0.050 (1,3)

0.054 (1,4)

0.078 (2,0)

0.079 (2,0)

0.080 (2,0)

0.093 (2,4)

0.125 (3,2)

0.112 (2,8)

0.156 (4,0)

0.287 (7,3)

0.179 (4,5)

0.187 (4,8)

0.090 (2,3)

0.187 (4,8)

0.210 (5,3)

0.240 (6,1)

0.244 (6,2)

0.250 (6,4)

0.312 (7,9)

0.027 (0,7)

0.020 (0,5)

0.025 (0,6)

0.024 (0,6)

0.045 (1,1)

0.027 (0,7)

0.040 (1,0)

0.025 (0,6)

0.050 (1,3)

0.030 (0,8)

0.050 (1,3)

0.065 (1,7)

0.062 (1,6)

0.080 (2,0)

0.039 (1,0)

0.050 (1,3)

0.032 (0,8)

0.039 (1,0)

0.035 (0,9)

0.062 (1,6)

0.055 (1,4)

0.063 (1,6)

0.050 (1,3)

0.057 (1,4)

M83528/007X001

M83528/007X002

M83528/007X007

M83528/007X005

M83528/007X004

0.421 (10,7)

0.427 (10,8)

0.480 (12,2)

0.487 (12,4)

0.488 (12,4)

0.500 (12,7)

0.335 (8,5)

0.324 (8,2)

0.312 (7,9)

0.324 (8,2)

0.312 (7,9)

M83528/007X006

0.625 (15,9)

0.400 (10,2)

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

O-Strip Tubing

NOMINAL DIMENSIONS

MILꢂDTLꢂ85328

PART NUMBER

PART

NUMBER

MILꢂDTLꢂ85328

PART NUMBER

PART

NUMBER

INCHꢆMMꢇ

8864-0136

8864-0060

8864-0173

8864-0156

8864-0161

8864-0090

8864-0095

8864-0142

8864-0172

8864-0153

8864-0100

8864-0101

8864-0102

8864-0104

8864-0171

8864-0105

8864-0163

8864-0139

8864-0162

0.085 (2,2)

0.090 (2,3)

0.103 (2,6)

0.110 (2,8)

0.115 (2,9)

0.125 (3,2)

0.130 (3,3)

0.145 (3,7)

0.149 (3,8)

0.156 (4,0)

0.168 (4,3)

0.177 (4,5)

0.035 (0,9)

0.040 (1,0)

0.050 (1,3)

0.040 (1,0)

0.045 (1,1)

0.050 (1,3)

0.040 (1,0)

0.050 (1,3)

0.062 (1,6)

0.045 (1,1)

0.062 (1,6)

0.070 (1,8)

0.125 (3,2)

0.050 (1,3)

0.062 (1,6)

0.069 (1,8)

0.092 (2,3)

M83528/011X008

8864-0143

8864-0168

8864-0147

8864-0167

8864-0110

8864-0160

8864-0120

8864-0144

8864-0050

8864-0125

8864-0127

8864-0170

8864-0166

8864-0135

8864-0055

8864-0159

8864-0053

0.177 (4,5)

0.188 (4,8)

0.216 (5,5)

0.228 (5,8)

0.250 (6,4)

0.312 (7,9)

0.330 (8,4)

0.375 (9,5)

0.400 (10,2)

0.422 (10,7)

0.490 (12,4)

0.513 (13,0)

0.550 (14,0)

0.623 (15,8)

0.630 (16,0)

0.079 (2,0)

0.120 (3,0)

0.125 (3,2)

0.169 (4,3)

0.125 (3,2)

0.188 (4,8)

0.192 (4,9)

0.250 (6,4)

0.235 (6,0)

0.250 (6,4)

0.200 (5,1)

0.319 (8,1)

0.414 (10,5)

0.438 (11,1)

0.447 (11,4)

0.366 (9,3)

0.375 (9,5)

M83528/011X003

M83528/011X004

M83528/011X007

M83528/011X005

M83528/011X001

M83528/011X006

M83528/011X002

8864-010462 0.146

(3.7)

0.091 (2.3)

0.055 (1.4)

0.071 (1.8)

0.059 (1.5)

0.071 (1.8)

0.094 (2.4)

0.035 (0.9)

0.087 (2.2)

0.039 (1)

8864-3714

8864-0103

8864-0091

8864-3515

8864-2618

8864-3824

8864-0137

8864-0141

8864-0231

8864-0180

8864-3715

0.146 (3.7)

0.138 (3.5)

0.094 (2.4)

0.138 (3.5)

0.102 (2.6)

0.150 (3.8)

0.094 (2.4)

0.126 (3.2)

0.071 (1.8)

0.063 (1.6)

0.146 (3.7)

0.039 (1)

0.059 (1.5)

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

D-Strips

RECOMMENDED GROOVE

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

DIMENSIONS ꢆ±0.002ꢇ

PART NUMBER

RAD

WIDTH

DEPTH

8865-0100

8865-0105

8865-0120

8865-0140

8865-0116

8865-0110

8865-0135

8865-0130

8865-0125

8865-0115

8865-0144

8865-0145

0.055 (1,4)

0.062 (1,6)

0.075 (1,9)

0.093 (2,4)

0.094 (2,4)

0.118 (3,0)

0.122 (3,1)

0.150 (3,8)

0.178 (4,5)

0.188 (4,8)

0.250 (6,4)

0.064 (1,6)

0.068 (1,7)

0.100 (2,5)

0.178 (4,5)

0.093 (2,4)

0.078 (2,0)

0.156 (4,0)

0.135 (3,4)

0.110 (2,8)

0.089 (2,3)

0.188 (4,8)

0.250 (6,4)

0.031 (0,8)

0.089 (2,3)

0.047 (1,2)

0.059 (1,5)

0.061 (1,5)

0.075 (1,9)

0.039 (1,0)

0.094 (2,4)

0.125 (3,2)

0.067 (1,7)

0.074 (1,9)

0.076 (1,9)

0.093 (2,4)

0.109 (2,8)

0.140 (3,6)

0.141 (3,6)

0.165 (4,2)

0.182 (4,3)

0.220 (5,6)

0.286 (7,3)

0.053 (1,3)

0.057 (1,4)

0.084 (2,1)

0.150 (3,8)

0.077 (2,0)

0.065 (1,7)

0.131 (3,3)

0.113 (2,9)

0.092 (2,3)

0.074 (1,9)

0.160 (4,1)

0.212 (5,4)

MB83528/003X001

MB83528/003X005

MB83528/003X010

MB83528/003X004

MB83528/003X002

MB83528/003X008

MB83528/003X007

MB83528/003X006

MB83528/003X003

MB83528/003X011

MB83528/003X012

Channel Strips

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

M83528/010X001

8868-0100

8868-0055

8868-0105

8868-0056

8868-0115

8868-0067

8868-0120

8868-0081

8868-0084

8868-0085

8868-0125

8868-0070

8868-0075

0.100 (2,5)

0.082 (2,1)

0.110 (2,8)

0.114 (2,9)

0.156 (4,0)

0.500 (12,7)

0.156 (4,0)

0.189 (4,8)

0.250 (6,4)

0.252 (6,4)

0.235 (6,0)

0.120 (3,0)

0.130 (3,3)

0.034 (0,9)

0.030 (0,8)

0.025 (0,6)

0.030 (0,8)

0.062 (1,6)

0.047 (1,2)

0.063 (1,6)

0.062 (1,6)

0.126 (3,2)

0.062 (1,6)

0.275 (7,0)

0.390 (9,9)

0.033 (0,8)

0.026 (0,7)

0.050 (1,3)

0.062 (1,6)

0.047 (1,2)

0.075 (1,9)

0.063 (1,6)

0.062 (1,6)

0.063 (1,6)

0.115 (2,9)

0.060 (1,5)

0.114 (2,9)

0.126 (3,2)

0.156 (4,0)

0.175 (4,4)

0.189 (4,8)

0.250 (6,4)

0.252 (6,4)

0.327 (8,3)

0.395 (1,0)

0.530 (13,5)

M83528/010X002

M83528/010X003

M83528/010X004

M83528/010X005

M83528/010X006

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

O-Strips

DIMENSIONS

RECOMMENDED GROOVE DIMENSIONS ꢆ±0.002ꢇ

MILꢂDTLꢂ85328

PART NUMBER

INCHꢆMMꢇ

PART NUMBER

WIDTH

HEIGHT

8863-0184

8863-0100

8863-0105

8863-0110

8863-0115

8863-0120

8863-0125

8863-0196

8863-0130

8863-0135

8863-0140

8863-0145

8863-0150

8863-0160

8863-0165

8863-0170

8863-0197

8863-0183

8863-0198

8863-0199

8863-0175

8863-0180

8863-0200

8863-0201

8863-0202

0.032 (0,8)

0.040 (1,0)

0.053 (1,3)

0.062 (1,6)

0.070 (1,8)

0.080 (2,0)

0.093 (2,4)

0.098 (2,5)

0.103 (2,6)

0.112 (2,8)

0.119 (3,0)

0.125 (3,2)

0.130 (3,3)

0.139 (3,5)

0.150 (3,8)

0.160 (4,1)

0.186 (4,7)

0.188 (4,8)

0.194 (4,9)

0.197 (5,0)

0.216 (5,5)

0.250 (6,4)

0.256 (6,5)

0.312 (7,9)

0.374 (9,5)

0.036 (0,9)

0.045 (1,1)

0.059 (1,5)

0.066 (1,7)

0.076 (1,9)

0.086 (2,2)

0.100 (2,5)

0.105 (2,7)

0.110 (2,8)

0.119 (3,0)

0.126 (3,2)

0.133 (3,4)

0.137 (3,5)

0.147 (3,7)

0.158 (4,0)

0.168 (4,3)

0.197 (5,0)

0.200 (5,1)

0.209 (5,3)

0.210 (5,3)

0.229 (5,8)

0.267 (6,8)

0.274 (7,0)

0.337 (8,6)

0.400 (10,2)

0.026 (0,7)

0.032 (0,8)

0.042 (1,1)

0.050 (1,3)

0.056 (1,4)

0.064 (1,6)

0.074 (1,9)

0.078 (2,0)

0.082 (2,1)

0.089 (2,3)

0.095 (2,4)

0.100 (2,5)

0.104 (2,6)

0.111 (2,8)

0.120 (3,0)

0.128 (3,3)

0.149 (3,8)

0.150 (3,8)

0.156 (4,0)

0.158 (4,0)

0.173 (4,4)

0.200 (5,1)

0.205 (5,2)

0.250 (6,4)

0.300 (7,6)

M83528/001X001

M83528/001X002

M83528/001X003

M83528/001X004

M83528/001X005

M83528/001X006

M83528/001X007

M83528/001X008

M83528/001X009

M83528/001X010

M83528/001X011

M83528/001X0012

M83528/001X013

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ELECTROSEAL CONDUCTIVE ELASTOMER

EXTRUSIONS

UIDE

P-Strips

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

PART

NUMBER

8867-0136

8867-0147

0.275 (7,0)

0.290 (7,4)

0.140 (3,6)

0.095 (2,4)

0.085 (2,2)

0.062 (1,6)

0.060 (1,5)

0.151 (3,8)

0.080 (2,0)

0.076 (1,9)

0.125 (3,2)

0.080 (2,0)

0.189 (4,8)

0.030 (0,8)

0.025 (0,6)

0.062 (1,6)

0.050 (1,3)

0.062 (1,6)

0.072 (1,8)

0.063 (1,6)

0.060 (1,5)

0.070 (1,8)

0.062 (1,6)

8867-0128 0.415

(10,5) 0.200

(5,1)

8867-0141 0.425

(10,8) 0.250

(6,4)

8867-0101 0.475

(12,1) 0.200

(5,1)

8867-0127 0.500

(12,7) 0.200

(5,1)

8867-0105 0.500

(12,7) 0.250

(6,4)

8867-0126 0.600

(15,2) 0.250

(6,4)

8867-0102 0.640

(16,3) 0.208

(5,3)

8867-0158 0.752

(19,1) 0.252

(6,4)

M83528/008X007

M83528/008X002

M83528/008X004

8867-0165 0.752

(19,1) 0.437

(11,1) 0.347

(8,8)

8867-0130 0.780

(19,8) 0.360

(9,1)

8867-0100 0.850

(21,6) 0.200

(5,1)

M83528/008X006

M83528/008X001

0.255 (6,5)

0.080 (2,0)

8867-0166 0.874

(22,2) 0.500

(12,7) 0.400

(10,2) 0.065

(1,7)

8867-0125 0.875

(22,2) 0.312

(7,9) 0.187

(4,8) 0.062

(1,6)

M83528/008X005

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

GEMINI™

OEXTRUSIONS

MULTI-EXTRUSION, BI-FUNCTIONAL

FEATURES

ELASTOMER GASKET

•

Combines the strength of silicone rubber with

Laird’ Gemini™ product line is a high-performance gasket

soluꢀon that combines a reliable environmental silicone

elastomer seal with an electrically conducꢀve elastome

Conducꢀve parꢀcle ﬁller results in a product with lower

material cost and an improved environmental seal against

water, moisture, dust and mildly corrosive atmospheric

condiꢀons due to smog.

Laird’ proprietary conducꢀve elastomer

EMI shielding materials and knowledge

•

Improved environmental seal

Improved EMI performance over lifeꢀme

Cost-eﬀecꢀve

Available in both standard and custom proﬁles

Ability to use ﬁnite element analysis to design

the best custom gasket for your applicaꢀon

Our conducꢀve extrusions oﬀer a wide choice of proﬁles

to ﬁt a large range of applicaꢀons. The cross-secꢀons

shown on the following pages are oﬀered as standard.

Custom dies can be built to accommodate your speciﬁc

desig

MARKETS

•

Wireless infrastructure

Remote radio units

Telecom cabinets

Radar

IT cabinets

All electronic cabinets or electronic chassis that

require both an environmental seal and EMI shielding

TYPICAL COEXTRUISON GASKET DESIGN

NONCONDUCTIVE ELASTOMER

CONDUCTIVE ELASTOMER

PARAMETER

Polymer matrix

Filler

TEST METHOD

NCE220

NCE251

NCE250

ECE72

Silicone

Ni/Graphite

Grey

ECE93

Silicone

Ni/graphite

Black

ECE116

Silicone

Ag/Al

Tan

ECE115

Silicone

Ag/Glass

Tan

Silicone

Color

Visual Inspecꢀon

ASTM D2240

ASTM D792

Blue

Grey

Orange

Hardness, Shore A

Density, g/cm3

1.2

2.3

1.9

Tensile strength, psi,

min.

ASTM D412

400

700

800

280

150

200

Elongaꢀon to break

ASTM D412

100-300%

150%

100-300%

100-301%

100-302%

Tear Strength,

ppi, min.

ASTM D624, die C

Compression set,

%, max.

ASTM D395

35%

160

10%

160

10%

160

30%

160

30%

160

32%

160

30%

160

Working Temperature

Maximum, oC

“MIL-DTL-83528C

(4.5.15)”

Minimum, oC

ASTM D1329

UL94

-55

Flame Retardance

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

GEMINI COEXTRUSIONS

8890-MGS103072-93

8890 0001 XX A

8890 0002 XX A

8894 0001 XX A

8898 0001 XX A

8898 0002 XX A

8899 0001 XX A

8898 0003 XX A

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

OVERVIEW

Laird provides a full line of fabricated conducꢀve

elastomers. These products are oﬀered in a wide range of

materials to meet your parꢀcular applicaꢀon. In addiꢀon

to the standard components shown, Laird can supply

molded and vulcanized EcE gaskets to meet custom

conﬁguraꢀons required to package electronic components

in either cast or sheet metal enclosures.

MOLDED O-RINGS

O-rings, when installed in a groove design that allows

10%ꢅ20% compression and 80%ꢅ95% gland ﬁll, will

provide both an EMI and moisture seal. Custom tools can

be fabricated for prototypes and producꢀon quanꢀꢀes

when diameters are larger than 2.000 in. (50,8 mm).

Round strips can also be vulcanized to create O-rings to

include parts with diameters larger than 3.000 in. (76,2

mm). Consult Laird sales department for sizes not shown

in this catalog.

SHEET MATERIAL

Table A lists thicknesses and sizes for our molded

sheet material, while Table 2, pages 14ꢅ17, shows the

compounds available for all of our conducꢀve silicone

elastomers.

FLAT WASHERS

HOW TO SPECIFY

Determine the standard Laird part number from Tables

1ꢅ8 on page 14 based upon conﬁguraꢀon.

Table 3 shows some of the standard sizes of washers that

can be die-cut from sheet material. Besides the circular

shape, intricate shapes can be designed and die-cut to

meet custom requirements.

MOLDED D-RINGS

Tables 4, 5 and 6 show standard sizes of molded rings.

These components, as in the O-rings above, can be

supplied spliced and vulcanized to dimensions in excess of

two inches I.D.

FLAT WAVEGUIDE GASKETS

The die-cut gaskets shown in Tables 7 and 8 are designed

to provide eﬀecꢀve EMI shielding and pressure sealing for

choke cover and contact ﬂanges. Gaskets shown in this

table can be supplied from the sheet materials shown in

Table A.

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

Molded EMI O-Rings

TABLE 1. MIL-DTL-83528 SERIES

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

LAIRD PART

NUMBER

MILꢂDTLꢂ83528

PART NUMBER

LAIRD PART

NUMBER

8563-0322-XX

8563-0068-XX

8563-0143-XX

8563-0334-XX

8563-0326-XX

8563-0343-XX

8563-0106-XX

8563-0069-XX

8563-0070-XX

8563-0243-XX

8563-0071-XX

8563-0108-XX

8563-0072-XX

8563-0196-XX

8563-0327-XX

8563-0073-XX

8563-0116-XX

8563-0091-XX

8563-0285-XX

8563-0074-XX

8563-0211-XX

0.050 (1,3)

0.145 (3,7)

0.150 (3,8)

0.176 (4,5)

0.260 (6,6)

0.270 (6,9)

0.295 (7,5)

0.301 (7,6)

0.364 (9,2)

0.415 (10,5)

0.057 (1,4)

0.426 (10,8)

0.070 (1,8)

0.446 (11,3)

0.051 (1,3)

0.489 (12,4)

0.070 (1,8)

0.492 (12,5)

0.070 (1,8)

0.500 (12,7)

0.100 (2,5)

0.551 (14,0)

0.070 (1,8)

0.610 (15,5)

0.070 (1,8)

0.612 (15,5)

0.103 (2,6)

0.632 (16,1)

0.062 (1,6)

0.676 (17,2)

0.070 (1,8)

0.676 (17,2)

0.070 (1,8)

0.063 (1,6)

0.070 (1,8)

0.062 (1,6)

0.070 (1,8)

0.030 (0,8)

0.070 (1,8)

0.048 (1,2)

0.070 (1,8)

M83528/002X018

8563-0075-XX

8563-0218-XX

8563-0076-XX

8563-0077-XX

8563-0344-XX

8563-0078-XX

8563-0079-XX

8563-0213-XX

8563-0279-XX

8563-0062-XX

8563-0080-XX

8563-0113-XX

8563-0089-XX

8563-0161-XX

8563-0094-XX

8563-0090-XX

8563-0165-XX

8563-0324-XX

8563-0095-XX

8563-0164-XX

8563-0166-XX

0.739 (18,8)

0.070 (1,8)

0.755 (19,2)

0.097 (2,5)

0.801 (20,3)

0.070 (1,8)

0.864 (21,9)

0.070 (1,8)

0.921 (23,4)

0.139 (3,5)

0.926 (23,5)

0.070 (1,8)

0.989 (25,1)

0.070 (1,8)

0.989 (25,1)

0.070 (1,8)

1.000 (25,4)

0.250 (6,4)

1.100 (27,9)

0.070 (1,8)

1.114 (28,3)

0.070 (1,8)

1.182 (30,0)

0.068 (1,7)

1.239 (31,5)

0.070 (1,8)

1.239 (31,5)

0.070 (1,8)

1.362 (34,6)

0.103 (2,6)

1.364 (34,6)

0.070 (1,8)

1.366 (34,7)

0.070 (1,8)

1.463 (37,2)

0.080 (2,0)

1.487 (37,8)

0.103 (2,6)

1.487 (37,8)

0.103 (2,6)

1.489 (37,8)

0.070 (1,8)

M83528/002X007

M83528/002X019

M83528/002X020

M83528/002X021

M83528/002X022

M83528/005X006

M83528/002X011

M83528/002X012

M83528/002X013

M83528/005X008

M83528/002X014

M83528/002X024

M83528/005X013

M83528/002X026

M83528/002X126

M83528/002X028

M83528/002X015

M83528/005X016

M83528/002X114

M83528/002X128

M83528/002X017

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

TABLE 1. MIL-DTL-83528 SERIES (CONT’D)

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

PART NUMBER

LAIRD PART

NUMBER

MILꢂDTLꢂ83528

PART NUMBER

LAIRD PART

NUMBER

M83528/005X022

M83528/002X132

8563-0122-XX

8563-0096-XX

8563-0167-XX

8563-0123-XX

8563-0097-XX

8563-0168-XX

8563-0280-XX

8563-0159-XX

8563-0098-XX

8563-0232-XX

8563-0180-XX

8563-0241-XX

8563-0216-XX

1.612 (40,9)

0.103 (2,6)

1.737 (44,1)

0.103 (2,6)

1.739 (44,2)

0.070 (1,8)

8563-0281-XX 3.989

(101,3) 0.070

(1,8)

8563-0274-XX 4.450

(113,0) 0.070

(1,8)

8563-0139-XX 4.690

(119,1) 0.062

(1,6)

8563-0315-XX 5.858

(148,8) 0.070

(1,8)

8563-0185-XX 6.000

(152,4) 0.103

(2,6)

8563-0234-XX 6.312

(160,3) 0.070

(1,8)

8563-0342-XX 7.322

(186,0) 0.103

(2,6)

8563-0226-XX 7.491

(190,3) 0.070

(1,8)

8563-0323-XX 8.750

(222,3) 0.250

(6,4)

8563-0263-XX 9.370

(238,0) 0.103

(2,6)

8563-0187-XX 9.984

(253,6) 0.139

(3,5)

8563-0339-XX 10.303

(261,7) 0.103

(2,6)

8563-0140-XX 12.812

(325,4) 0.125

(3,2)

M83528/005X023

M83528/002X134

1.790 (45,5)

0.103 (2,6)

M83527/002X155

1.862 (47,3)

0.103 (2,6)

1.989 (50,5)

0.070 (1,8)

2.000 (50,8)

0.250 (6,4)

2.050 (52,1)

0.103 (2,6)

2.367 (60,1)

0.103 (2,6)

2.614 (66,4)

0.070 (1,8)

3.158 (80,2)

0.062 (1,6)

3.209 (81,5)

0.070 (1,8)

3.806 (96,7)

0.125 (3,2)

M83528/002X142

O-rings with a diameter less than 3” (76,2 mm) will be molded.

O-rings with a diameter of 3” (76,2 mm) or more may be molded or spliced.

TABLE 2. MIL-DTL-83528/013 JAM NUT SEALS

LAIRD PART NUMBER

DIMENSIONS INCHꢆMMꢇ

SHELL

SIZE

MILꢂDTLꢂ38999/

MILꢂDTLꢂ81511

MILꢂDTLꢂ26482

8563-0073-XX

8563-0074-XX

0.551 (14,0)

0.676 (17,2)

0.739 (18,8)

0.801 (20,3)

0.864 (21,9)

0.989 (25,1)

1.114 (28,3)

1.239 (31,5)

1.364 (34,6)

1.487 (37,8)

1.737 (44,1)

0.070 (1,8)

0.103 (2,6)

8563-0075-XX

8563-0077-XX

9, 10

11, 12

13, 14

15, 16

17, 18

19, 20

23, 24

8563-0076-XX

8563-0079-XX

8563-0080-XX

8563-0089-XX

8563-0090-XX

8563-0095-XX

8563-0096-XX

8563-0080-XX

8563-0089-XX

8563-0090-XX

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

Flat Washer Gaskets

TABLE 3. MIL-DTL-83528 SERIES

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

LAIRD PART NUMBER

PART NUMBER

8560-0231-XX

8560-0234-XX

8560-0233-XX

8560-0097-XX

8560-0158-XX

8560-0435-XX

8560-0299-XX

8560-0143-XX

8560-0098-XX

8560-0331-XX

8560-0444-XX

8560-0200-XX

8560-0099-XX

8560-0100-XX

8560-0144-XX

8560-0145-XX

8560-0330-XX

8560-0311-XX

8560-0505-XX

8560-0453-XX

0.120 (3,0)

0.171 (4,3)

0.218 (5,5)

0.250 (6,4)

0.319 (8,1)

0.375 (9,5)

0.380 (9,7)

0.433 (11,0)

0.508 (12,9)

0.500 (12,7)

0.656 (16,7)

0.500 (12,7)

0.875 (22,2)

0.500 (12,7)

0.656 (16,7)

0.500 (12,7)

0.875 (22,2)

0.500 (12,7)

0.656 (16,7)

0.641 (16,3)

0.703 (17,9)

0.800 (20,3)

1.000 (25,4)

0.890 (22,6)

1.250 (31,8)

0.260 (6,6)

0.390 (9,9)

0.030 (0,8)

0.060 (1,5)

0.030 (0,8)

0.032 (0,8)

0.060 (1,5)

0.032 (0,8)

0.075 (1,9)

0.062 (1,6)

0.031 (0,8)

0.032 (0,8)

0.065 (1,7)

0.045 (1,1)

0.031 (0,8)

0.062 (1,6)

s0.062 (1,6)

0.032 (0,8)

0.156 (4,0)

0.062 (1,6)

0.468 (11,9)

0.625 (15,9)

0.562 (14,3)

0.750 (19,1)

0.422 (10,7)

0.750 (19,1)

0.960 (24,4)

M83528/012X001

M83528/012X002

M83528/012X004

M83528/012X003

M83528/012X005

M83528/012X007

M83528/012X006

M83528/012X008

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ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

Molded Waveguide Gaskets

TABLE 4. CIRCULAR “D” SECTION

NOMINAL DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

LAIRD PART NUMBER

PART NUMBER

M83528/013X002

M83528/013X004

M83528/013X006

M83528/013X008

M83528/013X011

M83528/013X012

M83528/013X017

8563-0126-XX

8563-0127-XX

8563-0128-XX

8563-0129-XX

8563-0131-XX

8563-0130-XX

8563-0133-XX

0.056 (1,4)

0.048 (1,2)

0.125 (3,2)

0.065 (1,7)

0.088 (2,2)

0.077 (2,0)

0.078 (2,0)

0.041 (1,0)

0.410 (10,4)

0.082 (2,1)

Full Radius

0.587 (14,9)

0.078 (2,0)

Full Radius

0.885 (22,5)

0.155 (3,9)

0.049 (1,2)

1.122 (28,5)

0.099 (2,5)

Full Radius

1.340 (34,0)

0.095 (2,4)

Full Radius

1.310 (33,3)

0.115 (2,9)

Full Radius

1.550 (39,4)

0.105 (2,7)

TABLE 5. RECTANGULAR “D” SECTION

WIDTH DIMENSIONS

INCHꢆMMꢇ

LENGTH DIMENSIONS

MILꢂDTLꢂ83528

INCHꢆMMꢇ

LAIRD PART NUMBER

PART NUMBER

MIN

MAX

MIN

MAX

M83528/006X001

M83528/006X002

M83528/006X003

M83528/006X005

8563-0253-XX

8563-0254-XX

8563-0255-XX

8563-0257-XX

0.285 (7,2)

0.295 (7,5)

0.983 (25,0)

0.993 (25,2)

0.485 (12,3)

0.495 (12,6)

0.983 (25,0)

0.993 (25,2)

0.619 (15,7)

0.629 (16,0)

1.243 (31,6)

1.325 (33,7)

1.355 (34,4)

5.265 (133,7)

5.295 (134,5)

TABLE 6. RECTANGULAR “O” SECTION

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

LAIRD PART NUMBER

PART NUMBER

1.368 (34,7)

± 0.012 (0,3)

1.616 (41,0)

± 0.015 (0,4)

11.866 (301,4)

± 0.015 (0,4)

2.449 (62,2)

± 0.020 (0,5)

3.451 (87,7)

± 0.024 (0,6)

0.868 (22,0)

± 0.010 (0,3)

0.991 (25,2)

± 0.010 (0,3)

1.116 (28,3)

± 0.012 (0,3)

1.449 (36,8)

± 0.013 (0,3)

1.951 (49,6)

± 0.004 (0,1)

0.103 (2.6)

± 0.003 (0,1)

0.103 (2,6)

± 0.003 (0,1)

0.103 (2,6)

± 0.003 (0,1)

0.139 (3,5)

± 0.004 (0,1)

0.139 (3,5)

± 0.004 (0,1)

M83528/013X013

M83528/013X018

M83528/013X023

M83528/013X030

M83528/013X037

8563-0248-XX

8563-0249-XX

8563-0250-XX

8563-0251-XX

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ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

Rectangular Waveguide Gaskets

TABLE 7.

DIMENSIONS INCHꢆMMꢇ

MILꢂDTLꢂ83528

LAIRD PART

NUMBER

PART NUMBER

F RADIUS

± 0.750

(19,1)

0.875

(22,2)

1.313

(33,4)

1.496

(38,0)

1.625

(41,3)

1.875

(47,6)

1.750

(44,5)

1.937

(49,2)

3.500

(88,9)

1.764

(44,8)

2.750

(69,9)

4.188

(106,4)

± 0.750

(19,1)

0.875

(22,2)

1.313

(33,4)

1.496

(38,0)

1.625

(41,3)

1.875

(47,6)

2.500

(63,5)

2.687

(68,3)

2.500

(63,5)

2.781

(70,6)

3.875

(98,4)

6.344

(161,1)

± 0.145

(3,7)

0.175

(4,4)

± 0.285

(7,2)

0.425

(10,8)

0.320

(8,1)

± 0.116

(2,9)

0.116

(2,9)

0.140

(3,6)

0.155

(3,9)

0.169

(4,3)

0.180

(4,6)

0.171

(4,3)

0.206

(5,2)

± 0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

0.027

(0,7)

± 0.469

(11,9)

0.563

(14,3)

0.875

(22,2)

0.450

(11,4)

0.469

(11,9)

1.150

(29,2)

0.250

(6,4)

0.250

(6,4)

0.313

(8,0)

0.125

(3,2)

0.312

(7,9)

M83528/013X001 8560-0104-XX

Fig. 1

M83528/013X003 8560-0105-XX

Fig. 1

M83528/013X005 8560-0106-XX

Fig. 1

M83528/013X007 8560-0103-XX

Fig. 1

M83528/013X009 8560-0107-XX

Fig. 1

M83528/013X015 8560-0108-XX

Fig. 1

M83528/013X016 8560-0113-XX

Fig. 2

M83528/013X020 8560-0114-XX

Fig. 2

M83528/013X027 8560-0116-XX

Fig. 2

0.630

(16,0)

0.760

(19,3)

0.905

(23,0)

1.130

(28,7)

0.505

(12,8)

0.633

(16,1)

1.880

(47,8)

0.882

(22,4)

1.155

(29,3)

2.160

(54,9)

0.385

(9,8)

0.405

(10,3)

0.505

(12,8)

1.130

(28,7)

1.380

(35,1)

0.880

(22,4)

1.882

(47,8)

2.300

(58,4)

4.310

(109,5)

0.226

(5,7)

0.156 (4,0)

0.141

0.270

(6,9)

M83528/013X028

M83528/013X031

Fig. 2

0.266 (6,8)

0.281 (7,1)

0.250

(6,4)

M83528/013X040 8560-0110-XX

Fig. 2

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

FABRICATED COMPONENTS

UIDE

The waveguide gaskets listed in the Waveguide Gasket

Selecꢀon Guide will ﬁt standard UG, CPR and CMR ﬂanges.

The leꢃers (A, B, C, D, E) shown in the “Gasket Conﬁg.”

column correspond to the MIL-DTL-83528/013 part

conﬁguraꢀons as follows:

Type A — Square & Rectangular Die-Cut Gaskets

Type B — Circular Die-Cut Gaskets

Type C — Molded Rectangular “O” Cross Secꢀon

Type D — Molded Circular “O” Cross Secꢀon

Type E — Molded Circular “D” Cross Secꢀon

TABLE 8. WAVEGUIDE GASKET SELECTION GUIDE

EIA

FREQUENCY

DESIGNATION

FLANGE DESCRIPTION

GASKET

MILꢂDTLꢂ83528/013

BAND

FLANGE TYPE

WAVEGUIDE SIZE

RANGE GHZ.

MILꢂW

CPR

CMR

CONFIG

PAGE NO.

001 (1)

UG-599/U

Cover

Choke

Cover

26.5 – 40.0

18.0 – 26.5

WR28

RG-96U (Silver)

UG-600A/U

UG-595/U

003 (1)

004

RG-53/U (Brass)

RG-121/U (Aluminum)

UG-597/U

WR42

UG-596A/U

Choke

Cover

Choke

Cover

Choke

Cover

Flat Contact

Choke

UG-598A/U

UG-419/U

UG-541A/U

RG-91/U (Brass)

RG-107/U (Silver)

005 (1)

006

12.4 – 18.0

10.0 – 15.0

WR62

WR75

007

008

CPR-75F

CPR-90F

UG-39/U

009

010 (2)

011

UG-135/U

UG-1736/U

UG-1737/U

RG-52/U (Brass) RG-

67/U (Aluminum)

UG-136A/U

8.2 -12.4

7.0 – 11.0

WR90

UG-40A/U

UG-136B/U

Choke

012

UG-40B/U

UG-1360/U

CPR-90G

Contact

Choke

013

014

UG-1361/U

UG-1494/U

WR102

UG-51/U

UG-138/U

Cover

015

UG-1734/U

RG-51/U (Brass)

CPR-112F

CPR-112G

CPR-137F

Flat Contact

Choke

016

017

018

019

UG-1735/U

7.05 – 10.0

WR112

RG-68/U (Aluminum)

UG-52B/U

UG-137B/U

UG-1358/U

Contact

Cover

UG-1359/U

UG-344/U

UG-138/U

UG-1732/U

Flat Contact

CMR-137

Flat Contact

Choke

020 (1)

021(1)

022

UG-1733/U

RG-50/U (Brass)

RG-108/U (Aluminum)

5.85 – 8.2

4.9 – 7.05

WR137

WR159

WR187

UG-343B/U

UG-440B/U

UG-1356/U

CPR-137G

Contact

023

UG-1357/U

UG-1730/U

CPR-159F

Flat Contact

CMR-159

Flat Contact

Cover

024 (1)

025 (1)

026

UG-1731/U

UG-149A/U

UG-407/U

UG-1728/U

CPR-187F

Flat Contact

CMR-187

Flat Contact

Choke

027 (1)

028 (1)

029

UG1729/U

RG-49/U (Brass)

RG-95/U (Aluminum)

3.95 – 5.85

3.30 – 4.90

UG-148C/U

UG-406B/U

UG-1352/U

UG-1353/U

UG-1726/U

UG-1727/U

CPR-187G

Contact

030

CPR-229F

Flat Contact

031 (1)

WR229

CMR-229

Flat Contact

032 (1)

033

UG-53/U

Cover

UG-584/U

UG-1724/U

CPR-248F

Flat Contact

CMR-284

Flat Contact

Choke

034 (1)

035 (1)

036

UG-1725/U

RG-48/U (Brass)

RG-75/U (Aluminum)

2.6 – 3.95

2.2 – 3.3

WR284

WR340

UG-54B/U

UG-585A/U

UG-1348/U

CPR-284G

Contact

037

UG-1349/U

UG-533/U

RG-112/U (Brass)

RG-112/U (Aluminum)

Flat Contact

CPR-340F

Flat Contact

038 (1)

039 (1)

040 (1)

041 (1)

UG-554/U

UG-435A/U

UG-437A/U

RG-104/U (Brass)

RG-105/U (Aluminum)

RG-69/U (Brass)

RG-103/U (Aluminum)

1.7- 2.6

WR430

WR650

CPR-430F

Flat Contact

UG-417A/U

UG-418A/U

1.12 – 1.7

Flat Contact

042 (1)

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

AUTOMATED FORMꢂINꢂPLACE

EMI GASKET TECHNOLOGIES

INTRODUCTION

Laird form-in-place is an automated system for dispensing

conducꢀve elastomer EMI shielding and grounding

gaskets onto metal or plasꢀc substrates. Form-in-place

is parꢀcularly well suited for cellularphones, PDAs, PC

cards, telecom base staꢀons, radios, and many other

compartmentalized cast or plasꢀc enclosures and

packaged electronic assemblies.

Uꢀlizing programmable 3-axis CNC dispensing equipment,

the compound is dispensed accurately onto the substrate and

creates a secure bond during the curing process. The repeatable

computer-controlled dispensing paꢃern insures consistency

between parts and rapid part program changes. In addiꢀon,

it supports all levels of volume ꢅ from prototyping to high-

volume electronic component producꢀon ꢅ via the use of one

or mulꢀple dispensing heads. The system is programmed to

apply custom gasket conﬁguraꢀons onto parts, to form mulꢀple

levelson the part, and on slopes up to approximately 70°.

Automated dispensing of compound is controlled

by sophisꢀcated computer soꢁware, which is

user-friendly and easy to work with.

FORM-IN-PLACE GASKETING

FEATURES AND BENEFITS

•

ꢁForm-in-place gaskeꢀng oﬀers a total cost savings in the

form of reduced raw materials, labor or assembly ꢀme

Laird RXP compounds are Room Temperature Vulcanizing

(RTV) elastomers and HXP compounds are High

•

ꢁRoom temperature cure gaskeꢀng materials eliminate

the need for costly heat curing systems, allowing the

use of inexpensive plasꢀc or metal substrates

Temperature Vulcanizing (HTV) elastomers, both ﬁlled with

proprietary conducꢀve parꢀcles. Dispensed gasket beads of

RXP compounds may be handled in 3 hours, and are cured

in 24 hours, under condiꢀons of standard temperature

and 50% Relaꢀve Humidity. Dispensed gasket beads

of HXP compounds can be handled aꢄer the materials

are cured in an oven. The compounds have a working

compression range from 10% to 50% of the gasket height,

with a recommended design compression of 30% against a

mechanical compression stop. Our product is designed to

support low closure forces and is compaꢀble with plasꢀc,

metal, and plated or chromate ﬁnished substrates.

•

ꢁSingle-component compounds eliminate the need for

mixing ingredients, thereby shortening producꢀon

cycles and eliminaꢀng related waste

•

ꢁEasy to program operaꢀng system allows for quick

part-to-part change-over, minimal tooling investment

for new designs, and prototype development in 24 to

48 hours

•

ꢁHigh shielding eﬀecꢀveness: 85ꢅ100 dB up to 10 GHz

•

ꢁThe dispensing system supports prototyping and high

volume producꢀon schedules in a space saving 4’ x 3’

[12 sq. ꢄ.] (1,2 m x 0,9 m [1,1 sq. m]) footprint

The required force to compress a given bead is a funcꢀon of the

compound and the gasket size; i.e. smaller gaskets require less

force than larger gaskets. Please refer to our technical data for

details. Gaskets are dispensed on substrates within a placement

tolerance of ± 0.001 inches and gasket cross-secꢀonal tolerances

from ± 0.003 to 0.007 inches. Refer to Table 1 on page 39 for

typical gasket dimensions and tolerances. As a normal course of

equipment operaꢀons, starꢀng points and terminaꢀon ends of

the gaskets will have proﬁles that are approximately 25% larger

than the running gaskets.

•

ꢁForm-in-place gaskets provide more criꢀcal packaging

space for board level components and smaller package

dimensions

•

ꢁExcellent adhesion on a wide variety of metal and

plasꢀc substrates including:

– aluminum and other casꢀng alloys

– stainless steel

– nickel copper plaꢀng (on plasꢀcs)

– copper, silver, and nickel ﬁlled paint (on plasꢀcs)

TYPICAL APPLICATION FOR FORM-IN-PLACE GASKETS:

•

ꢁLow compression force makes SN compounds an

excellent selecꢀon where the maꢀng surfaces lack

mechanical sꢀﬀness

ON A SIDE

IN A GROOVE

ON A FLAT

SURFACE

ON A RIDGE

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ELECTROSEAL CONDUCTIVE ELASTOMER

AUTOMATED FORMꢂINꢂPLACE

EMI GASKET TECHNOLOGIES

Laird form-in-place gaskeꢀng is ideal for

hand held electronics applicaꢀons.

PROGRAMMING SOFTWARE

EXCEPTIONAL QUALITY

Programming of the dispensing equipment can be

facilitated uꢀlizing part samples or part drawings. We

also support the following CAD formats: AutoCAD®, DXF®,

IGES®, Pro/ENGINEER®.

All material undergoes batch tesꢀng before applicaꢀon to

guarantee superior mechanical and electrical properꢀes.

All dispensed products are manufactured to the exacꢀng

requirements of our ISO 9001 cerꢀﬁed facility.

The soꢄware is user-friendly and includes several useful

tools to simplify the path programming. These include

scaling, symmetries, rotaꢀon, segment ends deﬁniꢀon,

and roboꢀc dispensing instrucꢀons.

PACKAGING

To prevent damage to the substrate and gasket, and to

facilitate handling, parts should be shipped in trays. Parts

should be held securely to the tray to prevent movement

during shipping, and packaged to avoid contact with each

othe

f required, Laird can design special packaging and

trays to suit your speciﬁc part requirements. Store in the

freezer prior to use.

All producꢀon parameters are controlled by the soꢄware

to include dispensing speed, start point, number of parts

on the pallet, ꢀme needed to process one part, and

automaꢀc shut-down for cartridge reloading.

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ELECTROSEAL CONDUCTIVE ELASTOMER

AUTOMATED FORMꢂINꢂPLACE

EMI GASKET TECHNOLOGIES

TABLE 1.

TABLE 2.

TYPICAL BEAD DIMENSIONS

ACCELERATED CURE AT HIGHER TEMPERATURES

50%RELATIVE HUMIDIT

CONDITIONS

MINIMUM

LANDING

AREA

0.024 IN. ꢆ0,6 MMꢇ BEAD

HEIGHT INCHꢆMMꢇ

WIDTH INCHꢆMMꢇ

Temperature °F (°C)

73 (23)

140 (60)

185 (85)

0.014 ± 0.003 (0,4 ± 0,1)

0.015 ± 0.003 (0,4 ± 0,1)

0.020 (0,5)

0.015 ± 0.003 (0,4 ± 0,1)

0.020 ± 0.003 (0,5 ± 0,1)

0.025 (0,6)

0.020 ± 0.003 (0,5 ± 0,1)

0.024 ± 0.003 (0,6 ± 0,1)

0.029 (0,7)

0.027 ± 0.004 (0,7 ± 0,1)

0.030 ± 0.004 (0,8 ± 0,1)

0.036 (0,9)

0.030 ± 0.004 (0,8 ± 0,1)

0.034 ± 0.004 (0,9 ± 0,1)

0.040 (1,0)

0.040 ± 0.004 (1,0 ± 0,1)

0.048 ± 0.005 (1,2 ± 0,1)

0.055 (1,4)

0.045 ± 0.005 (1,1 ± 0,1)

0.059 ± 0.006 (1,5 ± 0,2)

0.067 (1,7)

0.055 ± 0.006 (1,4 ± 0,2)

0.075 ± 0.007 (1,9 ± 0,2)

0.084 (2,1)

Time for 98% Cure (H

)

TABLE 3. MATERIAL SPECIFICATIONS

TEST

SNC70ꢂ

RXP

SNK55ꢂ

RXP

SNL60ꢂ

RXP

SNN60ꢂ

RXP

SNC70ꢂ

HXP

SNK60ꢂ

HXP

SNL70ꢂ

HXP

SNN65ꢂ

HXP

SIL35ꢂHXP

UNIT

SIL25ꢂRXP

METHOD

Elastomer

Silicone

Silver/

Silicone Silicone

Silver/ Silver/

Silicone

Nickel/

Graphite

Silver/

Non-

Nickel/

Non-

Filler

Copper Aluminium Nickel conducꢀve

Graphite Copper

Aluminium Nickel

Conducꢀve

Color

Gray

Tan

White

Gray

Tan

Transparent

Electric Properꢀes

Volume Resisꢀvity

ohm-cm

0.03

0.002

0.003

0.005

0.03

0.004

0.005

Shielding

eﬀecꢀveness

MIL-DTL-

83528C

ꢁꢁ200MHz to 10GHz

Mechanical Properꢀes

Hardness

Para. 4.5.12

>100

>90

>100

>90

>100

ASTM D2240

Shore A

ASTM D792

g/cm3

2.5

2.1

3.9

1.2

2.5

3.1

1.1

Density (cured)

Compression set

3.84

10(b)

200

ASTM D395

200

<20(a)

220

200

<20(b)

285

Adhesion strength (Al)

LT-FIP-CLE-03 N/cm2

150

140

180

>180

200

Compression

LT-FIP-CLE-07

deﬂecꢀon

See note

at 20% compression

at 40% compression

Temperature Range

lb/in

°C

1.5

6.9

1.2

5.2

1.9

8.3

1.7

6.4

3.2

1.5

7.3

2.3

See note (c)

(b)

11.5

10.5

See note

(b)

-50 to

125

-50 to 125

-50 to 100

-50 to 125

-50 to 150

-50 to 125

See note (c)

UL raꢀng

UL-94

TBD

Curing requirements

15°C to

40°C, 50%

23°C, 50%

Curing condiꢀons

Handling ꢀme

120°C

relaꢀve

humidity humidity humidity

humidity

10-25

minutes

1 hour

12hrs/mm

thick

Cure ꢀme

24 hours

1 hour

1.5 hours

1 hours

1.5 hours

1 hour

(a) Test method ASTM D575

(b) Contact Laird Applicaꢀon Engineering for test data.

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ELECTROSEAL CONDUCTIVE ELASTOMER

METAL IMPREGNATED

MATERIALS

ELECTROMET™ ORIENTED WIRE

ElectroMet oriented wire gaskets are EMI shielding and sealing

composites. Monel® or aluminum wires mbedded in the elastomer and

oriented perpendicular to the maꢀng surfaces provide the EMI sealing.

Solid or sponge silicone provides the weather sealing; however, solid

silicone weather seals are recommended for high-pressure applicaꢀons.

Silicone based oriented wire composites are capable of withstanding

temperature ranges from ꢅ70°F to 500°F (ꢅ56°C to 260°C).

Oriented wire materials are available in sheet or strip form with a

minimum thickness of 0.032 in. (0,8 mm). Material speciﬁcaꢀons and

informaꢀon for standard sheets and strips are provided in Tables 1

through 3.

Monel® wire is bonded into a silicone elastomer for uniform surface

and mulꢀple “spring” eﬀect with each contact point.

TABLE 3. ELECTROMET STRIP MATERIALS

TABLE 1.

MATERIAL CODE

ELASTOMER

Silicone Sponge

Per AMS 3195

WIRE SPECIFICATION

Monel: Alloy Per QQ N281

Dia. 0.0045 (0,114)

DIMENSIONS INCHꢆMMꢇ

END VIEW

PART NUMBER

8408-0100-XX

8408-0138-XX

8408-0102-XX

8408-0120-XX

8408-0130-XX

8408-0151-XX

8408-0105-XX

8408-0141-XX

8408-0127-XX

8408-0110-XX

8408-0290-XX

8408-0123-XX

8408-0133-XX

8408-0111-XX

8408-0124-XX

8408-0140-XX

8408-0137-XX

8408-0115-XX

8408-0139-XX

8408-0143-XX

8408-0116-XX

8408-0293-XX

8408-0126-XX

8408-0289-XX

8408-0118-XX

8408-0144-XX

8408-0134-XX

8408-0128-XX

8408-0117-XX

8408-0135-XX

8408-0147-XX

8408-0294-XX

8408-0148-XX

A. WIDTH

0.125 (3,2)

0.187 (4,8)

0.250 (6,4)

0.312 (7,9)

0.375 (9,5)

0.394 (10,0)

0.500 (12,7)

0.625 (15,9)

0.750 (19,1)

1.000 (25,4)

B. THICKNESS

0.062 (1,6)

0.125 (3,2)

0.250 (6,4)

0.020 (0,5)

0.062 (1,6)

0.125 (3,2)

0.187 (4,8)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.250 (6,4)

0.062 (1,6)

0.125 (3,2)

0.250 (6,4)

0.032 (0,8)

0.062 (1,6)

0.032 (0,8)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.187 (4,8)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.062 (1,6)

0.250 (6,4)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

Silicone Solid Per ZZR765

Class 2b Grade 40

Monel: Alloy Per QQ N281

Dia. 0.0045 (0,114)

Silicone Sponge

Per AMS 3195

S ilicone Solid Per ZZR765

Class 2b Grade 40

Aluminum: Alloy 5056 Per AMS 4182

Dia. 0.005 (0,127)

Aluminum: Alloy 5056 Per AMS 4182

Dia. 0.005 (0,127)

Note: Wire density per sq. in.: 700ꢅ900; per sq. cm 108ꢅ139

TABLE 2. ELECTROMET SHEET MATERIALS

DIMENSIONS INCHꢆMMꢇ

A. WIDTH

END VIEW

PART NUMBER

8408-0296-XX

8408-0200-XX

8408-0203-XX

8408-0206-XX

8408-0209-XX

8408-0212-XX

8408-0213-XX

8408-0215-XX

8408-0218-XX

8408-0221-XX

8408-0224-XX

8408-0227-XX

8408-0230-XX

8408-0233-XX

8408-0236-XX

8408-0239-XX

8408-0242-XX

8408-0245-XX

8408-0248-XX

8408-0251-XX

8408-0254-XX

8408-0257-XX

B. THICKNESS

0.125 (3,2)

0.032 (0,8)

0.045 (1,1)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.187 (4,8)

0.032 (0,8)

0.045 (1,1)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.032 (0,8)

0.045 (1,1)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.032 (0,8)

0.045 (1,1)

0.062 (1,6)

0.093 (2,4)

0.125 (3,2)

0.750 (19,1)

3.000 (76,2)

4.500 (114,3)

6.000 (152,4)

9.000 (228,6)

COMPRESSION-DEFLECTION FOR SOLID SILICONE

MATERIAL

THICKNESS

COMPRESSION FORCE PSI ꢆMPAꢇ AT DEFLECTION OF:

*10%

15%

20%

HOW TO SPECIFY

For PSA, change the ﬁꢄh digit to 9 for items with tape. Example:

0.045 (1,1)

0.062 (1,6)

0.125 (3,2)

40 (0,3)

85 (0,6)

115 (0,8)

100 (0,7)

165 (1,1)

180 (1,2)

155 (1,1)

240 (1,7)

245 (1,7)

280 (1,9)

345 (2,4)

290 (2,0)

8408-0200-59 becomes 8408-9200-59.

Replace XX with material code from Table 1.

Example: To request a 3.0 in. (76,2 mm) wide x 0.032 in. (0,8 mm)

thick strip with aluminum wire in solid silicone sponge,

use 8408-0200-59.

*Recommended

Note: Compression force for silicone sponge is approximately 15 psi to 75 psi.

Silicone sponge density is 0.02 lb/in3.

For further informaꢀon or for product samples, please contact

Laird Technologies sales department.

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

SPECIALTY

RODUCTS

ELECTROCOAT™

ElectroCoat is a thin, ﬂexible surface coaꢀng consisꢀng

of a silver-ﬁlled silicone elastome

he versaꢀle coaꢀng

can be easily applied to die-cut or molded foams for both

gasket and non-gasket applicaꢀons. It can also be applied

to molded or extruded elastomers, other polymers, and a

wide range of other materials.

•

Excellent shielding eﬀecꢀveness — greater than 90 dB

measured by transfer impedance

•

Solid, conꢀnuous, conducꢀve coaꢀng over the enꢀre

gasket surface, including the inner die-cut surfaces of

foam gaskets

•

Coated foam gaskets have very low compression force

Excepꢀonally wide compression range from 10%

to 70% deﬂecꢀon to accommodate uneven gaps in

enclosure housings

•

Flexible coaꢀng withstands gasket compression with

no decrease in shielding eﬀecꢀveness aꢄer 1000

cycles of 40% compression

Extruded proﬁles shown on pages 18ꢅ22 are available

with neoprene core.

ORDERING INFORMATION

Determine if PSA is needed. If so, replace the 5th digit

in the part number with “9

”

Select desired core material from Table 1 and insert in

place of Y

Select two digit ElectroCoat from Table 2 and insert in

place of ZZ.

A unique custom idenꢀﬁcaꢀon number will be

assigned by sales.

8550

ꢂX

XXX

ꢂYY

ꢂZZ

Standard

Series

Unique

idenꢀﬁcaꢀon

Core

Material*

ElectroCoat

(Coaꢀng

Number

PSA

number assigned

Material)

by Laird

TABLE 1

YY #

CORE MATERIAL*

Silicone Foam

Solid Silicone

Neoprene Foam

TABLE 2

ZZ COATING #

MATERIAL

Silver/Silicone

*Other core materials may be available.

Consult Laird sales department.

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

SPECIALTY

RODUCTS

PROFILE DIMENSION

MOUNTING INFORMATION

BOARD TO CHASSIS CONDUCTIVE STAND-OFF

Laird oﬀers a mulꢀ-funcꢀonal grounding

0.316

(8,0)

device that provides electrical contact between the

boꢃom of printed circuit boards and enclosure housings.

The snap in feature allows for easy assembly and secure

retenꢀon. Once inserted, the part makes contact with

the base of the printed circuit board on a grounding pad

or trace, assuring superior grounding.

0.456 (11,6)

•

Solves EMI and/or ESD problems via superior

grounding (maximum 0.8 Ohm DC resistance)

Provides damping of vibraꢀon and spacing between

grounded surfaces

0.175

(4,5)

Available in two standard lengths (custom lengths

also available)

•

Design of part facilitates simple roboꢀc automaꢀon

Minimum compression force required within

operaꢀng range (see chart below)

ORDERING INFORMATION

Select part from table below. Insert desired compound

number in place of XX. Custom lengths are also available.

PART NOUMBER

8569-0127-XX

8569-0131-XX

ECE COMPOUND 85

Silver/Glass

LENGTH

0.250 (6,4)

0.125 (3,2)

ECE COMPOUND 22

Nickel/Graphite

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ELECTROSEAL CONDUCTIVE ELASTOMER

CORROSION OF EMI GASKETS

Generally, eﬀecꢀve RF joints depend on having very high

GALVANIC CORROSION

conducꢀvity; therefore, reducing conducꢀvity to decrease

corrosion may greatly reduce shielding eﬀecꢀveness. Some

new research has produced materials that are good RF

conductors, but poor D.C. conductors. These materials may

be able to reduce corrosion and sꢀll maintain high shielding

levels. Laird is in the forefront of this research.

Corrosion can manifest itself in many forms. Some

common forms are galvanic, piꢈng, and crevice corrosion.

However, galvanic corrosion is the major concern in

shielding applicaꢀons. Galvanic corrosion is driven by the

interacꢀon of the gasket and the electronic enclosure,

since in a shielded joint there are oꢄen two dissimilar

materials in inꢀmate contact.

AN ION CONDUCTION PATH

The ionic conducꢀon medium that is most responsible for

corrosion is wate

here are other ionic conductors such

as moist air, but the majority of corrosion problems will

be caused by water or water-based soluꢀons. The basic

principle is that the metals are slightly soluble in wate

. You

can someꢀmes taste a metallic taste in water, especially

if the water is a liꢃle acidic. In a good ionic conductor

like salt water, or water with a high acid content, the ions

are relaꢀvely stable, and more metal will dissolve into

the wate

. A

ood ionic conductor like salt water will also

allow dissolved ions to move freely in the soluꢀon. The

dissolved ions tend to migrate through the water toward

the electrode of opposite polarity. The posiꢀvely charged

ions will migrate towards the cathode while the negaꢀvely

charged ions will migrate towards the anode.

BASIC GALVANIC CONDITIONS

There are three condiꢀons that must exist for galvanic

corrosion to occur:

Two electrochemically dissimilar materials present

An electrically conducꢀve path between the two materials

An ionic conducꢀon path (typically a corrosive

environment) between the materials

If any of these three condiꢀons is missing, galvanic

corrosion will not occu

f we examine each of these

condiꢀons in detail, we will not only understand galvanic

corrosion, but also know how to prevent it.

ELECTROCHEMICALLY DISSIMILAR METALS

Of the three condiꢀons necessary for galvanic corrosion,

the most important is the electrochemical diﬀerence

between metals. Commonly available materials have

diﬀerent electrochemical potenꢀals; even pure metal at

the microscopic level. This is why a block of steel siꢈng by

itself corrodes. The order in which metals will corrode is

always from the most anodic (acꢀve) to the most cathodic

(noble). This means that when two dissimilar metals are

put together, only the more anodic metal will corrode.

The only way to totally prevent dissolved ions from

migraꢀng is to interrupt their path, such as with a vacuum

or by maintaining them at very low temperatures. The

speed at which they migrate can also be reduced by many

orders of magnitude by using poor ionic conductors as

barriers. Placing metals in dry air, or coaꢀng the metals

with a poor ionic conductor such as paint, greatly reduces

corrosion rates. Some metals form their own barriers

that prevent or restrict ion migraꢀon. For example, under

normal atmospheric condiꢀons aluminum corrodes in air,

producing a thin coaꢀng of aluminum oxide. The aluminum

oxide is an extremely poor ionic conductor and chokes

oﬀ the ﬂow of oxygen to the aluminum metal beneath

the oxide coaꢀng. This demonstrates how by-products of

corrosion can dramaꢀcally reduce corrosion rates.

This method is used extensively in prevenꢀng corrosion by

plaꢀng a more anodic metal over a more cathodic metal.

The more anodic metal will then sacriﬁce itself (corrode

ﬁrst) and protect the metal underneath from corrosion.

This is the reason for the good corrosion resistance of zinc

plated steel. Even when scratched, the zinc coaꢀng that

surrounds the scratch protects the exposed steel from

corroding unꢀl the zinc near the scratch is consumed.

As in the above example of zinc coaꢀng on steel, the anodic

material does not need to completely cover the more

cathodic material to oﬀer protecꢀon. It only needs to be

close by. The eﬀecꢀve distance between the anodic metal

and the cathodic metal depends on the environment. This

distance is generally dependent on the conducꢀvity of the

electrolyte. In the case of typical electronic equipment this

distance is usually the size of the microdroplets of water

formed by condensaꢀon. In severe environments, this

distance can be 0.250 in. (6,4 mm) or more.

ELECTRICAL CONDUCTION

The second condiꢀon required for galvanic corrosion,

electrical conducꢀon, is the hardest to prevent. Metals are

all good conductors of electricity, and most joints between

metals are made with metal fasteners. The amount of

electrical current that ﬂows is dependent on the rate of

corrosion, but in most cases is very small.

Dramaꢀcally reducing the conducꢀvity of an electrical

path between two metals has liꢃle eﬀect on the corrosion

rates except where very strong electrolytes are involved.

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ELECTROSEAL CONDUCTIVE ELASTOMER

CORROSION OF EMI GASKETS

The volume resisꢀvity of the elastomers and the weight

GALVANIC CORROSION OF ELECTRICALLY

CONDUCTIVE ELASTOMERS

of the metal coupons were measured before, and then

again aꢄer the salt spray test. From this data, the change

in volume resisꢀvity for the elastomer and the weight loss

for the metal coupons were calculated. With these two

pieces of data it is possible to assess the compaꢀbility of

the various elastomer/metal couples. This informaꢀon

can then be used as a design guidance tool to determine

which combinaꢀons of conducꢀve elastomer gasket and

metal ﬂange are appropriate for a parꢀcular applicaꢀon.

The following corrosion data indicate the performance of

the galvanic couples in a very corrosive environment and

thus represent a worst-case scenario.

The galvanic series provides a relaꢀve ranking for selecꢀng

compaꢀble metallic couples. However, electrically

conducꢀve elastomers are a composite material that

behaves diﬀerently from metals due to diﬀusion rates

and elastomeric nature of the gaskets. In addiꢀon, the

presence of corrosion inhibitors which conꢀnuously

coat the exposed ﬂanges also aﬀects the corrosion rate.

Therefore, the direct applicaꢀon of the metallic-based

galvanic series to the conducꢀve elastomers could be

misleading. The corrosion behavior of the conducꢀve

elastomers is aﬀected by the nature of the ﬁller parꢀcles,

the permeability of the elastomer matrix, and the

presence of corrosion inhibitors.

Weight Loss of Metal Coupons (Part 1 of Galvanic Couple)

— Five diﬀerent metallic materials were evaluated. The

ﬁve metallic materials included chromated aluminum,

Galvalume® (a 55% Al-45% Zn hot-dip coated steel), ꢀn

plated steel, zinc plated steel and stainless steel (Table 1).

These materials represent some of the common types of

sheet metal used to manufacture enclosures.

Electrically conducꢀve elastomers are eﬀecꢀve shielding

materials because they provide good aꢃenuaꢀon to

electromagneꢀc radiaꢀon, while at the same ꢀme

providing an environmental seal. When conducꢀve

elastomers are assembled in an enclosure, they are

in inꢀmate contact with some type of metal ﬂange

and readily conduct current. These two condiꢀons,

inꢀmate contact with a metallic substrate and electrical

conducꢀvity, create a galvanic couple. Signiﬁcant

corrosion of one of the components of this couple

can occur under suitable condiꢀons of: 1) conducꢀve

environment (i.e., salt water, acid, etc.) and 2) corrosion

potenꢀal diﬀerence between the elastomer-metal couple

(the diﬀerence between the Electromoꢀve Force (EMF)

values of the two materials). If the elastomer corrodes, an

insulaꢀng corrosion product is formed that reduces the

conducꢀvity of the elastome

FIGURE 1. TEST ASSEMBLY PER MIS-47057

On the other hand, if the metal substrate corrodes, the

metal loss could threaten the integrity of the ﬂange

and the corrosion products could adversely eﬀect the

performance of the elastome

hen designing the

enclosure it is important to avoid condiꢀons that can lead

to signiﬁcant corrosion. The following data are intended

to be a guide to help in choosing the appropriate type of

couple(s) so as to avoid or minimize these condiꢀons.

FIGURE 2.

CONDUCTIVE WASHER

FIGURE 3. METAL COUPON

Corrosion Test

ꢅ To evaluate the impact of corrosion

on the elastomer/metal galvanic couples test samples

were exposed to 500 hours of salt spray in accordance

with missile speciﬁcaꢀon MIS-47057. The test ﬁxtures

were assembled as per Figure 1. The dimensions of the

electrically conducꢀve elastomer washers are shown in

Figure 2 and the metal coupons are shown in Figure 3.

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ELECTROSEAL CONDUCTIVE ELASTOMER

CORROSION OF EMI GASKETS

TABLE 1. METAL COUPONS TESTED

it would be criꢀcal to look at the relaꢀve anode (metal)

to cathode (elastomer) areas, the thickness of the ﬂange

and the corrosiveness of the environment. It is not

recommended that the galvanic couples with an extreme

metal coupon weight loss raꢀng (gray) be used under any

condiꢀons.

METAL COUPON

BASE METAL

COATING

Aluminum

6061-T6

1006

Chromate

55% Al-45% Zn

hot-dip coated

Galvalume®

Tin Plated Steel

Zinc Plated Steel

Stainless Steel

1010

304

Electroplated Tin

Electroplated Zinc

None

Volume Resisꢀvity of Conducꢀve Elastomers

(Part 2 of Galvanic Couple)

ꢅ Conducꢀve elastomers are

essenꢀally a composite material made up of an elastomer

matrix and small ﬁller parꢀcles, usually metallic. Even the ﬁller

parꢀcles can have a composite nature since many are coated.

This composite structure can result in a corrosion behavior that

may not follow the well known galvanic series. The elastomer

compounds that were evaluated are listed in Table 2.

The percent weight loss was calculated for all of the metal

coupons according to equaꢀon 1.

EQUATION 1

TABLE 2. ELASTOMERS TESTED

ELASTOMER

FILLER

Silicone

Inert Al

Ag Plated Cu

Ag Plated Al

Ag Plated Ni

Ag Plated Glass

Ag Plated Al

Ni Plated Graphite

Ag Plated Al

In equaꢀon 1, Weight Before is the weight of the metal

coupon before the test and Weight Aꢄer is the weight

aꢄer the test once the corrosion products were removed.

In Table 3 (page 55), a corrosion performance raꢀng was

developed from this data for the metal coupon part of

the galvanic couple only. This table does not provide any

informaꢀon on how the elastomer part of the galvanic

couple will hold-up.

Silicone

Fluorosilicone

Silicone

EPDM

When exposed to a corrosive environment one of the

most important characterisꢀcs of a conducꢀve elastomer

is its ability to maintain its iniꢀal shielding eﬀecꢀveness.

As corrosion products form in the elastomer it usually

results in a loss of shielding eﬀecꢀveness. Generally, as

shielding eﬀecꢀveness decreases there is a tendency for the

conducꢀvity of the elastomer to decrease (or resistance to

increase). To assess the eﬀect of very corrosive environments

on the elastomer part of the galvanic couples, the volume

resisꢀviꢀes of the elastomers were measured before

and aꢄer the corrosion test. In Graphs 1ꢅ5 on page 54, a

side-by-side comparison is presented for each elastomer

of its volume resisꢀvity before and aꢄer exposure to the

corrosive environment. The change in volume resisꢀvity is

the diﬀerence between these bars (before and aꢄer). It is

important to note that the Y-axis is a log scale. Each chart

corresponds to a diﬀerent metallic substrate. The change was

usually posiꢀve which means a loss in conducꢀvity. These

charts do not provide any informaꢀon on how the metal

coupon part of the galvanic couple will hold up.

The corrosion performance raꢀngs, color coded for ease

of recogniꢀon with a legend, are provided below the

table. The divisions for the corrosion performance raꢀngs

were established by visual assessment to diﬀerenꢀate

signiﬁcant diﬀerences of metal loss on the coupons. The

elastomer compound numbers are listed in columns

across the top of the table, including the elastomer and

ﬁller material. The metal coupons are listed in rows along

the side of the table. The intersecꢀon of a row and a

column gives the weight loss raꢀng for the metal coupon

when used with that parꢀcular elastome

. For the galvanic

couples in which the metal coupon experiences liꢃle

weight loss (yellow raꢀng), the metal coupon is probably

the cathode (electrode where reducꢀon occurs) and/

or the couple has a small potenꢀal diﬀerence. In this

case the metal substrate would not experience much

corrosion, even in very corrosive environments.

At the other extreme, the galvanic couples in which

the metal coupon experiences a large weight loss (dark

green raꢀng), the metal coupon would be the anode

(electrode where oxidaꢀon occurs). In this case the metal

substrate would experience extensive corrosion in the

very corrosive environments. A large metal coupon weight

loss (dark green raꢀng) does not preclude the use of this

galvanic couple, but in the design

For some of the elastomers, the increase in the volume

resisꢀvity is large. In these cases, the conducꢀve

elastomer was probably the anode. This condiꢀon results

in a signiﬁcant amount of corrosion of the elastomer ﬁller

parꢀcles, which makes it much less conducꢀve.

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

CORROSION OF EMI GASKETS

At the other extreme there were a number of elastomers

in which there was only a very small percent increase

in volume resisꢀvity. In these cases, the conducꢀve

elastomer was probably the cathode or the galvanic

couple had a very small corrosion potenꢀal diﬀerence.

Under these condiꢀons there was very liꢃle loss of

conducꢀvity aꢄer exposure to a corrosive environment.

How to Use the Charts

ꢅ When deciding on a conducꢀve

elastomer, it is important to examine the potenꢀal impact

of galvanic corrosion. From a corrosion standpoint, the

best design is an elastomer/metal ﬂange galvanic couple

that will result in the lowest corrosion rate. The charts

(Table 3 and Graphs 1ꢅ5) in this secꢀon are intended

to be used as a guide for choosing the least corrosive

galvanic couple (other design consideraꢀons should also

be taken into account when using these charts, such as

restricꢀons on enclosure materials and environmental

sealing requirements). To arrive at the best choice(s)

for a parꢀcular applicaꢀon the impact of corrosion on

both halves of the galvanic couple must be examined.

One half is the weight loss on the metal substrate and

the other half is the change in volume resisꢀvity for the

elastome

he combined eﬀect will dictate the corrosion

performance of the galvanic couple/ ﬁnished component.

Design Consideraꢀons

ꢅ When choosing a conducꢀve

elastomer for a parꢀcular design, especially in a

potenꢀally corrosive environment, it is important to look

at shielding requirements and the type of galvanic couple

that will be created. In deciding which couple best serves

the design requirements two factors will have to be

considered:

The impact of the galvanic couple on the enclosure

material (Table 3).

The impact of the galvanic couple on the volume

In Table 3, pick out the appropriate row(s) based on the

choice of the enclosure material(s) and then note the

elastomer compound(s) that has the lowest metal coupon

weight loss. Then go to the appropriate Graphs 1ꢅ5, based

on the metal substrate(s) of choice, and ﬁnd the change in

volume resisꢀvity for the elastomer compound(s) that you

have just idenꢀﬁed from Table 3.

resisꢀvity of the elastomer, Graphs 1ꢅ5 on page 54.

The impact of the galvanic couple on the corrosion of the

enclosure material can be gauged by the metal coupon

weight loss raꢀng on Table 3 (page 55). As the color

changes, the ﬂange area on the enclosure will experience

increasing amounts of corrosion.

The elastomers that have the lowest change in volume

resisꢀvity will represent the elastomer/metal substrate

combinaꢀon(s) that will create the least corrosive couple.

If a combinaꢀon of metal substrate with a very low weight

loss and elastomer with a very small change in volume

resisꢀvity is not idenꢀﬁed, then a compromise will have to

be made. In that case go through the same process but,

now look at metal substrates with slightly higher weight

losses and/or elastomers with slightly larger changes in

volume resisꢀvity. Aꢄer a candidate is selected it is always

best to test the elastomer(s) in the speciﬁc applicaꢀon.

Metal substrate factors to consider when choosing a

elastomer/metal couple:

•

Allowable enclosure material(s)

Eﬀect of weight loss/corrosion on the funcꢀon of the

enclosure

•

Area of exposed enclosure material close to elastomer

The impact of corrosion on the shielding eﬀecꢀveness of

the elastomer can be gauged by the change in volume

resisꢀvity, see Graphs 1ꢅ5 on page 47. The greater the

increase in volume resisꢀvity aꢄer exposure to a corrosive

environment the greater should be the drop-oﬀ in

shielding eﬀecꢀveness.

EXAMPLE

Assume the enclosure is aluminum.

From the aluminum row in Table 3, elastomer

compounds #89 and 96 will cause the lowest weight

loss on the aluminum metal substrate.

Elastomer factors to consider when choosing an

elastomer/metal couple:

From Graph 1 (Chromated Aluminum) compound #89

has the lowest change in volume resisꢀvity and 96 is a

close second

•

Shielding requirements

Change in volume resisꢀvity of elastomer in corrosive

environments

As long as the elastomer matrix and iniꢀal

aꢃenuaꢀons are acceptable, choose either compound

#89 or 96.

•

Environmental sealing requirements

Required compression properꢀes

www.lairdtech.com

ELECTROSEAL CONDUCTIVE ELASTOMER

CORROSION OF EMI GASKETS

ELASTOMER VOLUME RESISTIVITY

(Salt spray is considered a very corrosive environment and represents a worst-case scenario)

EcE 14, EcE 80, EcE81 and EcE85 are legacy compounds.

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ELECTROSEAL CONDUCTIVE ELASTOMER

ELASTOMER GALVANIC

COMPATIBILITY CHART

TABLE 3. METAL COUPON WEIGHT LOSS RATING*

COMPOUND NUMBER: ELASTOMER AND FILLER MATERIAL

METAL

SUBSTRATE

SIL AG/

FSIL NI/

GRAPHITE

SIL NI/

SIL AG/CU

SIL AG/AL

SIL AG/NI

FSIL AG/AL

EPDM AG/AL

GLASS

GRAPHITE

Chromated Al

Galvalume®

•

Tin Plated

Steel

•

Zinc Plated

Steel

•

Stainless Steel

*This chart to be used in conjuncꢀon with Graphs 1ꢅ5 on page 40.

EcE 14, EcE 80, EcE81 and EcE85 are legacy compounds.

Liꢃle to no weight loss on

metal coupon; less than 0.25%.

Acceptable in all environments.

Substanꢀal amount of

weight loss on metal coupon;

between 0.50% and 1.25%.

Not acceptable in corrosive

environments; for less

corrosive applicaꢀons consult

with Laird applicaꢀons

enginee

Moderate amount of weight

loss on metal coupon; between

0.25% and 0.50%. May not be

acceptable in very corrosive

environments.

Extreme amount of weight

loss on metal coupon;

greater than 1.25%. Not

recommended in any

environments.

www.lairdtech.com

Americas: +1.800.634.2673

Europe: +420.488.575277

ASEAN: +65.6243.8022

China: +86.757.2563.8860

India: +91.80.40740.400 x448

Japan: +81.45.473.6808

Korea: +82.10.8706.7469

Taiwan: +886.2.22901234 x163

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EMI-CAT-ECE 080615

Any information furnished by Laird and its agents is believed to be accurate and reliable. All specifications are subject to change without

notice. Responsibility for the use and application of Laird materials rests with the end use

ince Laird and its agents cannot be aware of all

potential uses. Laird makes no warranties as to the fitness, merchantability or suitability of any Laird materials or products for any specific or

general uses.

Laird, Laird Technologies, Inc or any of its affiliates or agents shall not be liable for incidental or consequential damages of any

kind. All Laird products are sold pursuant to the Laird Technologies’ Terms and Conditions of sale in effect from time to time, a copy of which

will be furnished upon request.

other marks are trademarks or registered trademarks of Laird Technologies, Inc. or an affiliate company thereof. Other product or service

names may be the property of third parties. Nothing herein provides a license under any Laird or any third party intellectual property rights.

Laird-Signal-Laird-Tech-8863-LT20NE2192

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