RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
WS-3375-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.750HX24L	200
0077006102 Laird - Performance Materials	FINGERSTOCK BECU 8.1X406.4MM	2168
4742PA22101800 Laird - Performance Materials	GSKT FAB/FOAM 3.8X457.2MM DSHAPE	0
24B09-BFA016000T Orbel	FINGER STOCK BECU ADHESIVE MOUNT	87
4519PA51H01800 Laird - Performance Materials	GASKET FABRIC/FOAM 15X457.2MM SQ	3108
21118373 Laird - Performance Materials	MF LOAD SERIES 1/4X12	0
55-46000 Parker Chomerics	FINGERSTOCK 0.07X0.5X24"	50
3029060080100 Würth Elektronik Midcom	WE-SMGS SURFACE MOUNT SOLDERABLE	897
WS-3310-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .535WX.196HX24L	99
0077006302 Laird - Performance Materials	GASKET BECU 8.1X9.04MM	0
25-55CPS-BD-16 Leader Tech Inc.	COPPER BERYLLIUM FINGERSTOCK EMI	565
WS-3640-KB-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.375HX24L	100
10-04-8817-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.125" 1'	155
302064032 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	83
WS-3325-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .280WX.252HX24L	99
5401-0003-60-300 Leader Tech Inc.	NI/C FILLED SILICONE; 0.062" DIA	1
3029060060050 Würth Elektronik Midcom	WE-SMGS SURFACE MOUNT SOLDERABLE	1027
4071AB51S01800 Laird - Performance Materials	GK SNCU NRS PU V0 REC	0
21148373 Laird - Performance Materials	MF500-117 .25X12 ECCOSORB	0
4202PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 6.4X457.2MM DSHAPE	383

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)