RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
3030602 Würth Elektronik Midcom	GASKET FABRIC/FOAM 6MMX1M DSHAPE	115
4211PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 10X457.2MM RECT	0
67B8G2507006215R00 Laird - Performance Materials	SP,CON,8,AU,TNR	0
3020906 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	19
WS-3520-KF-2400 3G Shielding Specialties	FAB/FOAM GASKET .600WX.160HX24L	40
4082PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 9.5X457.2MM RECT	410
4048PA51H01800 Laird - Performance Materials	SQUARE	0
2108693-4 TE Connectivity AMP Connectors	1.1H SPRING FINGER W/EMBOSS	88542
0077004002 Laird - Performance Materials	GASKET BECU 7.11X9.04MM	0
81-02-14306-2000 Parker Chomerics	FINGERSTOCK 0.13X0.37X16"	484
4098PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 15X457.2MM RECT	0
0097057402 Laird - Performance Materials	FINGERSTOCK BECU 7X406.4MM	0
67BCG2004005508R00 Laird - Performance Materials	SMD CONTACT 2.0X4.0X5.5	0
0077007302 Laird - Performance Materials	NOSG STR BF PSA	0
0077002002 Laird - Performance Materials	GASKET BECU 15.24X13.51MM	0
4612PA51H01800 Laird - Performance Materials	GASKT FAB/FOAM 12.7X457.2MM RECT	0
0077004802 Laird - Performance Materials	GASKET BECU 8.1X18.54MM	0
4216PA51G01800 Laird - Performance Materials	RECTANGLE	0
4522PA22101800 Laird - Performance Materials	GASKET FABRIC/FOAM 4X457.2MM SQ	196
3021005 Würth Elektronik Midcom	GASKET FABRIC/FOAM 10MMX1M RECT	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)