RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
1053840001 Woodhead - Molex	SPRING CONTACT 0.40MM - 0.80MM H	351
0077008802 Laird - Performance Materials	GASKET BECU 14.3X37.5MM	0
30B19-BFA024000T Orbel	FINGER STOCK BECU TWIST SERIES S	74
331011452048 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	1043
4131PA51H01800 Laird - Performance Materials	GASKT FAB/FOAM 12.7X457.2MM BELL	1097
WS-3610-KB-2400 3G Shielding Specialties	FAB/FOAM GASKET .315WX.090HX24L	100
4609PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 10.16X457.2MM DSHP	404
WS-3205-KD-2400 3G Shielding Specialties	FAB/FOAM GASKET .150WX.040HX24L	90
WS-3225-KD-2400 3G Shielding Specialties	FAB/FOAM GASKET .394WX.080HX24L	82
3851290 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	50
0097050017 Laird - Performance Materials	AP,STR,SNB,PSA	73
0077007002 Laird - Performance Materials	GASKET BECU 8.1X406.4MM	0
14-18ML-SN-24 Leader Tech Inc.	COPPER BERYLLIUM FINGERSTOCK EMI	0
4240PA51H01800 Laird - Performance Materials	GASKT FAB/FOAM 7.62X457.2MM DSHP	0
3-2199250-3 TE Connectivity AMP Connectors	3.2H SHLD FINGER LOOSE TYP C SMT	38086
4110HA51G01800 Laird - Performance Materials	D-SHAPE	0
WS-3265-KD-2400 3G Shielding Specialties	FAB/FOAM GASKET .630WX.315HX24L	70
4609PA51G01800 Laird - Performance Materials	GSKT FAB/FOAM 10.16X457.2MM DSHP	0
3020603 Würth Elektronik Midcom	GASKET FABRIC/FOAM 6MMX1M RECT	58
331211503040 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	1661

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)