RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
WS-3345-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .420WX.380HX24L	70
4694PA51G01800 Laird - Performance Materials	GASKET FAB/FOAM 12.7X457.2MM REC	0
WS-3635-KB-2400 3G Shielding Specialties	FAB/FOAM GASKET .600WX.250HX24L	100
4186PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 5.1X457.2MM RECT	297
30504 Würth Elektronik Midcom	CONDUCTIVE NI/CU GLASS SLEEVE 1M	3
1053860004 Woodhead - Molex	ANTI SNAG SPRING CONT 1.0UM GLD	36969
3091010 Würth Elektronik Midcom	CONDUCTIVE SHIELDING GASKET 1000	57
0097097502 Laird - Performance Materials	FINGERSTOCK BECU 20.32X474.98MM	0
1054390004 Woodhead - Molex	CLIP SPRING ASSY 1.95MM	0
WS-3220-KD-2400 3G Shielding Specialties	FAB/FOAM GASKET .160WX.080HX24L	89
4228PA51G01800 Laird - Performance Materials	D-SHAPE	0
WS-3525-KF-2400 3G Shielding Specialties	FAB/FOAM GASKET .750WX.250HX24L	50
WS-3340-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.375HX24L	99
5401-0005-80-300 Leader Tech Inc.	NI/C FILLED SILICONE 25FT ROLL	0
WS-3370-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .750WX.750HX24L	97
0097052002 Laird - Performance Materials	GASKET BECU 9.4X406.40MM	375
0097065002 Laird - Performance Materials	FINGERSTOCK BECU 25X406.4MM	0
10-04-2865-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.093" 1'	284
WS-3410-KP-2400 3G Shielding Specialties	FAB/FOAM GASKET .275WX.060HX24L	96
331081302025 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	5490

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)