RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
0077009802 Laird - Performance Materials	GASKET BECU 8.1X368.3MM	0
1437259-6 TE Connectivity AMP Connectors	SHIELD FINGER NICKEL 2.49MM	26161
4184PA22101800 Laird - Performance Materials	GSKT FAB/FOAM 3.8X457.2MM DSHAPE	0
3021707 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	134
0097052702 Laird - Performance Materials	GASKET BECU 7.11X406.4MM	0
10-05-6419-S6305 Parker Chomerics	CHO-SEAL S6305 0.156X0.156" 1'	17
0077002502 Laird - Performance Materials	GASKET BECU 9.4X18.4MM	1328
4212PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 4.95X457.2MM SQ	15639
5409-0004-20-300 Leader Tech Inc.	M83528/009B004, AG/AL FILLED SIL	0
81-01-14618-2000 Parker Chomerics	FINGERSTOCK 0.1X0.3X16"	61
3022510 Würth Elektronik Midcom	GASKET FABRIC/FOAM 25MMX1M RECT	121
4283PA51G01800 Laird - Performance Materials	GASKET FAB/FOAM 4X457.2MM DSHAPE	0
10-04-2865-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.093" 1'	111
38401203 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
4164PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 19.1X457.2MM REC	642
1746136-1 TE Connectivity AMP Connectors	SHIELD FINGER 1520 AU PL VERSION	7491
1551576-5 TE Connectivity AMP Connectors	SHIELD FINGER, LOOSE PIECE	76633
5409-0004-40-300 Leader Tech Inc.	M83528/009D004, AG/AL FILLED FLO	0
4692PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 6.4X457.2MM DSHAPE	3614
4209PA51G01800 Laird - Performance Materials	GASKT FAB/FOAM 3.94X457.2MM RECT	0

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)