RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
38401304 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	4
0097051502 Laird - Performance Materials	GASKET BECU 19.3X609.6MM	0
5401-0006-60-300 Leader Tech Inc.	NI/C FILLED SILICONE; 0.093" DIA	3
2286211-3 TE Connectivity AMP Connectors	HIGH CURRENT SPRING FINGER	60579
4157PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 5.1X457.2MM RECT	435
4081PA51G01800 Laird - Performance Materials	RECTANGLE	0
0077009302 Laird - Performance Materials	GASKET BECU 8.26X406.4MM	123
0077001502 Laird - Performance Materials	GASKET BECU 15.24X6.35MM	5850
0097050002 Laird - Performance Materials	GASKET BECU 15.24X609.60MM	191
4980PA51H01800 Laird - Performance Materials	GASKET FABRIC/FOAM 7X457.2MM SQ	0
0097052502 Laird - Performance Materials	.140X.370 GASKET FABRIC O/ FOAM	0
1551572-5 TE Connectivity AMP Connectors	PRE-LOADED SPRING FINGER 1.8MM	12094
S0911-46R Harwin	RFI SHIELD CLIP COMPACT TIN SMD	131
0097055302 Laird - Performance Materials	FINGERSTOCK BECU 3.81X406.4MM	0
30225015 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0
55-50000 Parker Chomerics	FINGERSTOCK 0.235X0.58X24"	16
19-04-27546-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.062" 1'	189
0097062102 Laird - Performance Materials	FINGERSTOCK BECU 11.176X406.4MM	0
07-0702-9006 Parker Chomerics	POLA SOLID SHEET 36X9X0.062"	4
38401105 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	4

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)