RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
10-05-4308-6502 Parker Chomerics	CHO-SEAL 6502 0.312X0.312" 1'	81
19-05-11440-6502 Parker Chomerics	CHO-SEAL 6502 0.145X0.246" 1'	114
37-131-1013-02400 Parker Chomerics	SOFT SHIELD 3700 EMI 1013 24"	919
07-0701-9006 Parker Chomerics	POLA SOLID SHEET 36X9X0.062"	14
37-131-1030-02400 Parker Chomerics	SOFT SHIELD 3700 EMI 1030 24"	299
77-12-3150-02400 Parker Chomerics	SOFT SHIELD 3500 EMI 3150 24"	480
07-0701-9012 Parker Chomerics	POLA SOLID SHEET 36X9X0.125"	3
55-50000 Parker Chomerics	FINGERSTOCK 0.235X0.58X24"	16
19-04-27546-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.062" 1'	189
07-0702-9006 Parker Chomerics	POLA SOLID SHEET 36X9X0.062"	4
55-46000 Parker Chomerics	FINGERSTOCK 0.07X0.5X24"	50
10-04-8817-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.125" 1'	155
07-0201-0237 Parker Chomerics	POLA SPONGE STRIP 11'X0.5X0.093"	23
19-04-22371-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.043" 1'	419
55-54200 Parker Chomerics	FINGERSTOCK 0.08X0.25X16"	0
07-0202-0094 Parker Chomerics	POLA SPONGE STRIP 11'X0.5X0.125"	19
81-02-14306-2000 Parker Chomerics	FINGERSTOCK 0.13X0.37X16"	484
08-5302-UN Parker Chomerics	METALASTIC EMI GEL 0.03X11.5X22"	4
19-04-25875-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.050" 1'	191
81-02-14274-2000 Parker Chomerics	FINGERSTOCK 0.06X0.45X16"	246

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)