EMI Shielding Materials
Many variations of shielding materials are available from National Power & Signal, the primary focus however for our products is the enclosure, cabinet or housing that requires an EMI gasket that can also act as an environmental seal. Following is a data sheet outlining the specific properties and technical information of the Nickel Graphite in Silicone elastomer material. Also shown is the technical data on the electrically conductive pressure sensitive adhesive or PSA.
Product: Silicone base with Nickel Graphite (Ni/g) conductive filler
Electrical Properties
Unit
Tolerance
Value
Volume Resistivity
Ohm-cm
Max.
0.040
Shielding Effectiveness 20MHz - 10GHz (E-Field)
dB
Min.
90
Physical Properties
Durometer (Hardness)
Shore A
+/- 7
75
Specific Gravity
23/23 deg C.
+/- 13%
2.7-3.3
Tensile Strength
PSI
Min.
270
Elongation
%
Min/Max
250
Tear Strength
PPI
Min.
35
Temperature
deg C.
Min/Max
-65/+200
Product: PSA, Conductive
Properties
Unit
Peel Adhesion
70 oz/in width (ult.)
19.8N/2.5cm
Shear Strength
2.2 psi indefinite
15.2 kPa
Elongation
N/A
Tensile Strength
N/A
Temperature Range
34 deg C / 107 deg C
Electrical Resistance (*1)
0.005 ohms/sq
Shelf Life (*2)
1 yr
Storage Temperature
23 deg C
R.H.
50%
All of the electrically conductive silicone elastomer compounds are available in sheet form ranging from .020 to .125 in thickness and sheet sizes that are
10X 10 12X 12 12X 18 and 15X 20.
Standard Sheet Sizes
Thickness
Sheet Size
.020
10X 10
.032
10X 10
.062
10X 10
Tolerance +/- .006
.093
10X 10
.125
10X 10
.020
12X 12
.032
12X 12
.062
12X 12
Tolerance +/- .007
.093
12X 12
.125
12X 12
.020
12X 18
.027
12X 18
.030
12X 18
.032
12X 18
.040
12X 18
Tolerance +/- .010
.047
12X 18
.060
12X 18
.062
12X 18
.093
12X 18
.125
12X 18
Standard Sheet Sizes
.020
15X 20
.032
15X 20
.062
15X 20
Tolerance +/- .010
.093
15X 20
.125
15X 20
The electrically conductive compounds can also be extruded, several standard shapes are available including solid round profiles and hollow profiles.
Solid Round Extruded
Dia
Hollow Round
OD
Extruded
ID
.040
.070
.025
.053
.093
.035
.062
.103
.040
.070
.125
.045
.080
.125
.062
.093
.156
.050
.103
.177
.079
.112
.250
.125
.125
.312
.192
.130
.375
.250
.150
.437
.250
.160
For a listing of additional profile shapes or for information on a custom extrusion profile contact National Power & Signal.
.188
.216
.250
Custom die cut Nickel Graphite in silicone gasket with PSA. Also shown is Nickel Graphite in silicone in rolls and sheets.
Custom die cut Nickel Graphite in silicone gasket without PSA. Approximate size 2.00X 1.75 material thickness .062 for small rf transmitter enclosure.
Custom die cut Nickel Graphite in silicone gasket with PSA.
National Power & Signal also manufactures EMI gaskets using oriented wire in silicone. This type of gasket material provides excellent conductivity from the main body of the enclosure or cabinet to the door or entry system of the design. The silicone elastomer is available in a solid or sponge, provides good environmental protection and is very economical to use in most industrial shielding applications.
This gasket material is also available with a pressure sensitive adhesive. Following is technical data on the oriented wires in silicone.
SOLID SILICONE
FLUOROSILICONE
Shielding dB 200 KHz
70
70
70
70
70
85
100 MHz
125
100
130
125
100
130
1.0 GHz
125
100
130
125
100
125
Fuel/Chem Resistant
NO
NO
NO
YES
YES
YES
Closing Force (psi)
25-90
25-90
25-90
25-90
25-90
25-90
Compression Set (%)
25
25
25
25
25
25
Temp Range ( C )
-60/200
-60/200
-60/200
-55/200
-55/200
-55/200
Wire Count/ sq-in
900
900
900
900
900
900
Column
1
2
3
1
2
3
Shown are six different material configurations, the first three are in standard solid silicone and the last three are in fluorosilicone for applications requiring resistance to chemicals, fuels and solvents.
SILICONE SPONGE
Shielding dB 200 KHz
70
70
70
100 MHz
120
85
130
1.0 GHz
125
70
125
Fuel/Chem Resistant
NO
NO
NO
Closing Force (psi)
5-50
5-50
5-50
Temp Range ( C )
-60/200
-60/200
-60/200
Wire Count/ sq-in
650
650
650
Column
1
2
3
Shown are nine separate material specifications for solid silicone, fluorosilicone and silicone sponge. When choosing a material you must include all of the information provided in the specific column that is applicable to your design requirements. The same information can also be used to order samples and to produce a procurement specification.
Die cut oriented wire in silicone sponge gasket strips.
