RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
1746136-1 TE Connectivity AMP Connectors	SHIELD FINGER 1520 AU PL VERSION	7491
1551576-5 TE Connectivity AMP Connectors	SHIELD FINGER, LOOSE PIECE	76633
2040852-1 TE Connectivity AMP Connectors	SHIELD FINGER 0820 N-B WITH SE	159525
1551631-5 TE Connectivity AMP Connectors	1SHIELD FINGER, LOOSE PIECE	6458
3-2199250-3 TE Connectivity AMP Connectors	3.2H SHLD FINGER LOOSE TYP C SMT	38086
1734300-1 TE Connectivity AMP Connectors	SHIELD FINGER 3025-Z1-T	567
2108613-5 TE Connectivity AMP Connectors	2.4H SPRING FINGER W/EMBOSS	0
1565322-1 TE Connectivity AMP Connectors	SHIELD FINGER 1608	97248
1551575-5 TE Connectivity AMP Connectors	PRE-LOADED SPRING FINGER 3MM	36417
2108614-5 TE Connectivity AMP Connectors	2.7H SPRING FINGER W/EMBOSS	23377
1871059-1 TE Connectivity AMP Connectors	SHIELD FINGER 1715 ON TAPE (EM	3625
1447009-7 TE Connectivity AMP Connectors	SHIELD FINGER 3525	3668
2339640-1 TE Connectivity AMP Connectors	SPRING FINGER	0
1554825-1 TE Connectivity AMP Connectors	RFI SHIELD FING CU ALLOY AU SLDR	0
2108609-6 TE Connectivity AMP Connectors	3.0H SPRING FINGER WITH EMBOSS	0
2108610-6 TE Connectivity AMP Connectors	1.4H SPRING FINGER WITH EMBOSS	0
2108613-6 TE Connectivity AMP Connectors	2.4H SPRING FINGER WITH EMBOSS	0
1734298-1 TE Connectivity AMP Connectors	SHIELD FINGER	0
2108611-6 TE Connectivity AMP Connectors	1.7H SPRING FINGER WITH EMBOSS	0
1734300-2 TE Connectivity AMP Connectors	SHIELD FINGER 3025-Z1-T	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)