Datasheet

80
www.lairdtech.com
81
www.lairdtech.com
EMI ESSENTIALSEMI ESSENTIALS
ELECTROSEAL CONDUCTIVE ELASTOMER
CASE STUDY
EXAMPLE
A Telecommunication customer A is looking for a gasket for RRU chassis. The chassis will be made of Aluminum by casting.
There is an existing design including groove. Groove dimension is as follows. The customer is looking for an electromagnetic
shielding larger than 50 dB for the chassis. And high reliability is required considering RRU unit will be exposed in open air
and sustain various weather condition such as snow, rain, fog, etc.
Selection Process Conclusion
Select elastomer base Take reference of Table 1 Silicone
All the three bases can meet resistance requirement
against weather, but silicone is the most cost effective
one. And also best on availability and processibility.
Select ller system "Take reference of Table 3 for galvanic performance and
Material Selection Table 6
1. Ag/Al ller would be most compatible with casting
aluminum.
2. Ni/Graphite is a cost effective solution but still accept-
able. Can be a candidate for future cost/performance
comparison.
3. Better use a hybrid design considering high reliability
requirement.
4. Both ller system can provide high shielding. But nal
performance would rely also on nal design."
"Hybrid (NCE+ECE),
ECE81(Ag/Al)
or ECE93(Ni/Graphite) "
Design Shape & Dimension
Closure force Medium closure force required because the RRU unit need
to sustain water ush without high pressure
Hollow cross section
Is there an existing design?
(part/groove/ange/inter-
face)
There is an existing groove design. But can not nd
corresponding groove recommendation in brochure.
Would need a design on gasket.
Contact Laird FAE for it.
What's the shape? Existing groove design is rectangle shaped. A standard
double D co-extrusion might work
Double D co-extrusion or
custom design
Decide dimension "Filling percentage >90% to bear water ush
Compression >=25% considering large coplanarity of
chassis and cover
Final FEA possible to conrm the design
Co-extrusion required because the total length is 1600
mm"
How to mount the gasket? Would need a PSA to hold the strip in groove
But a friction t design can also be done for easy assem-
bly and cost saving. Example
ELECTROSEAL CONDUCTIVE ELASTOMER
PRODUCT SELECTION GUIDE
Benet Ag (Silver) AgCu AgNi AgAl AgGlass Ni NiAl NiGraphite Carbon Non-Conductive
Silicone
good all purpose
material
ECE082/083 ECE080/094 ECE084 ECE081 ECE085 ECE100 ECE032 ECE072/093 ECE087 NCE220
Fluorosilicone
fuel and oil
resistant
-NA- ECE088 ECE090 ECE050/089 ECE011 -NA- -NA- ECE092 -NA- -NA-
EPDM
biohazard
resistant
-NA- -NA- -NA- ECE096 -NA- -NA- -NA- ECE095 ECE013 -NA-
Benet AgCu AgNi AgAl NiGraphite Non-Conductive
RXP - room
temperature cure
simple dispense
process
SNK55 SNN60 SNL60 SNC70 SIL25
HXP - heat cure longer shelf life SNK60 SNN65 SNL70 SNC70 SIL35
ECE POLYMER MATERIAL MATRIX
FIP RESIN MATRIX