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
10”X 10” 12”X 12” 12”X 18” and 15”X 20”.
Standard Sheet Sizes
|
Thickness |
Sheet Size |
|
.020” |
10”X 10” |
|
.032” |
10”X 10” |
|
.062” |
10”X 10”
Tolerance +/- .006” |
|
.093” |
10”X 10” |
|
.125” |
10”X 10” |
|
.020” |
12”X 12” |
|
.032” |
12”X 12” |
|
.062” |
12”X 12”
Tolerance +/- .007 |
|
.093” |
12”X 12” |
|
.125” |
12”X 12” |
|
.020” |
12”X 18” |
|
.027” |
12”X 18” |
|
.030” |
12”X 18” |
|
.032” |
12”X 18” |
|
.040” |
12”X 18”
Tolerance +/- .010 |
|
.047” |
12”X 18” |
|
.060” |
12”X 18” |
|
.062” |
12”X 18” |
|
.093” |
12”X 18” |
|
.125” |
12”X 18” |
|
Standard Sheet Sizes |
|
|
.020” |
15”X 20” |
|
.032” |
15”X 20” |
|
.062” |
15”X 20”
Tolerance +/- .010 |
|
.093” |
15”X 20” |
|
.125” |
15”X 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 2.00”X 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.
