RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
080B315-024000 Orbel	GASKET FABRIC FOAM BELL SHAPED 0	98
37-131-1022-02400 Parker Chomerics	SOFT SHIELD 3700 EMI 1022 24"	901
0097052102 Laird - Performance Materials	GASKET BECU ALLOY 13X406.4MM	142
0077001602 Laird - Performance Materials	GASKET BECU 8.1X4.27MM	15316
10-04-W267-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.090" 1'	555
30B03-BFA024000T Orbel	FINGER STOCK BECU TWIST SERIES S	11
38401406 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	3
3021003 Würth Elektronik Midcom	GASKET FABRIC/FOAM 10MMX1M RECT	440
4081PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 12.7X457.2MM REC	242
4186PA22101800 Laird - Performance Materials	GASKET FAB/FOAM 5.1X457.2MM RECT	0
0077001102 Laird - Performance Materials	GASKET BECU ALLOY 15.24X406.4MM	0
0097062402 Laird - Performance Materials	FINGERSTOCK BECU 10.67X406.4MM	0
4206PA51G01800 Laird - Performance Materials	GASKET FABRIC/FOAM 10X457.2MM SQ	322
WS-3335-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .375WX.375HX24L	97
3021025 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	87
19-04-28402-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.065" 1'	290
4882PA51H01800 Laird - Performance Materials	GASKT FAB/FOAM 15.2X457.2MM BELL	0
3100069 TE Connectivity AMP Connectors	3100069=SEALEDFINGR1715EMBOS	38325
3030804 Würth Elektronik Midcom	GASKET FABRIC/FOAM 8MMX1M DSHAPE	88
120220-0315 VEAM	MICRO UNIVERSAL CONTACT Z 4.0MM	35249

RFI and EMI - Contacts, Fingerstock and Gaskets

1. Overview

RF/IF (Radio Frequency/Intermediate Frequency) and RFID (Radio Frequency Identification) systems require effective electromagnetic interference (EMI) and radio frequency interference (RFI) shielding to maintain signal integrity. Contacts, fingerstock, and gaskets are critical components for ensuring electrical continuity and shielding performance in electronic enclosures. These components prevent electromagnetic leakage while maintaining mechanical functionality in connectors, housings, and assemblies.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Contacts	Conductive elements for maintaining electrical connections under compression	RF connectors, PCB grounding pads
Fingerstock	Resilient metal strips with finger-like projections for continuous shielding	Server chassis, military equipment
Gaskets	Conductive elastomers or mesh materials for sealing gaps	Automotive sensors, medical devices

3. Structure and Composition

Typical structures include:

Contacts: Beryllium copper or phosphor bronze cores with conductive platings (gold, silver, nickel)
Fingerstock: Canted coil springs or stamped metal fingers with corrosion-resistant coatings
Gaskets: Silicone rubber with embedded silver-aluminum particles or wire mesh

4. Key Technical Parameters

Parameter	Typical Range	Significance
Contact Resistance	0.1-10 m	Affects signal transmission efficiency
Shielding Effectiveness	60-120 dB (100 MHz-10 GHz)	Determines EMI/RFI attenuation
Compression Force	0.5-5 N/mm	Impacts mechanical durability
Temperature Range	-55 C to +150 C	Defines operational stability

5. Application Fields

Main industries include:

Telecommunications (5G base stations, microwave links)
Automotive (V2X communication systems, radar sensors)
Aerospace (avionics shielding compartments)
Medical (MRI shielding enclosures)

6. Leading Manufacturers and Products

Manufacturer	Representative Products
Parker Chomerics	CHO-SEAL conductive gaskets
Laird Performance Materials	Form-in-Place EMI gaskets
3M	EMI Shielding Tapes 9703/9706
Samtec	RFI/EMI shielded connectors

7. Selection Recommendations

Considerations include:

Frequency range of the application (higher frequencies require tighter tolerances)
Environmental conditions (temperature, humidity, chemical exposure)
Material compatibility (avoid galvanic corrosion between mating surfaces)
Cost-effectiveness (balance performance vs. budget constraints)

Case Study: In automotive radar systems, Parker Chomerics' silicone-based gaskets reduced EMI leakage by 40% compared to traditional metal fingerstock.

8. Industry Trends

Key development directions:

Miniaturization for 5G mmWave applications
Low-PIM (Passive Intermodulation) material formulations
Multi-functional integration with thermal management
RoHS-compliant plating processes (eliminating hexavalent chromium)