RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
38401204 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
0097062202 Laird - Performance Materials	FINGRSTK BECU ALY 11.176X406.4MM	0
0097095502 Laird - Performance Materials	FINGERSTOCK BECU 11.43X381MM	90
10-04-2737-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.250" 1'	83
1827625-1 TE Connectivity AMP Connectors	SHIELD FINGER 3014 ANTI OVER STR	58180
1053840003 Woodhead - Molex	SPRING CONTACT 0.30MM - 0.55MM H	6542
WS-3515-KF-2400 3G Shielding Specialties	FAB/FOAM GASKET .445WX.106HX24L	249
67SLG030030050PI00 Laird - Performance Materials	METAL FILM OVER FOAM CONTACTS	8962
4499PA51H01800 Laird - Performance Materials	GASKT FABRIC/FOAM 5X457.2MM RECT	0
060D250-024000 Orbel	GASKET FABRIC FOAM D-SHAPED 0.06	100
4228PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 3.8X457.2MM DSHAPE	445
4850-12-1212-0500 Parker Chomerics	SOFT SHIELD 4850 12"X12" 5MM	32
81-02-14308-2000 Parker Chomerics	FINGERSTOCK 0.22X0.6X16"	249
4741PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 6.5X457.2MM RECT	378
0097078617 Laird - Performance Materials	GASKET BECU 8.1X13.08MM	0
331276483050 Würth Elektronik Midcom	WE-SECF SMT EMI CONTACT FINGER	3810
060R394-024000 Orbel	GASKET FABRIC FOAM RECTANGULAR 0	100
3851030 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	50
4186PA51G01800 Laird - Performance Materials	GASKET FAB/FOAM 5.1X457.2MM RECT	0
21B03-BFA000356N Orbel	FINGER STOCK BECU SLOT-MOUNT 0.1	100

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)