RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
331031321515 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	1946
4084PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 12.7X457.2MM SQ	207
0097058402 Laird - Performance Materials	FINGERSTOCK BECU 9.65X406.4MM	0
3021002 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	120
7156-10001250-71 Leader Tech Inc.	.156" T X 1.00" ID X 1.250" OD K	50
2199248-5 TE Connectivity AMP Connectors	SHIELD FINGER, LOOSE PIECE, TYPE	29906
0097097402 Laird - Performance Materials	FINGERSTOCK BECU 4.6X406.4MM	536
120220-0313 VEAM	MICRO UNIVERSAL CONTACT Z 3.0MM	69801
120220-0311 VEAM	MICRO UNIVERSAL CONTACT Z 1.8MM	60056
0077009102 Laird - Performance Materials	GASKET BECU 15.24X457.2MM	0
3020605 Würth Elektronik Midcom	GASKET FABRIC/FOAM 6MMX1M RECT	86
2134078-1 TE Connectivity AMP Connectors	RFI SHIELD FING CU ALLOY AU SLDR	0
5401-0003-20-300 Leader Tech Inc.	M83528/001B003, AG/AL FILLED SIL	8
3851070 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	50
0097091302 Laird - Performance Materials	FINGERSTOCK BECU 15.82X381MM	80
SG020157R-48.00 Leader Tech Inc.	FSG, .02"H X .157"W X 48"L	1017
6-30T-BD-24 Leader Tech Inc.	COPPER BERYLLIUM FINGERSTOCK EMI	6
SG106315K-48 Leader Tech Inc.	FSG, .106"H X .315"W X 48"L	0
093S093-024000 Orbel	GASKET FABRIC FOAM SQUARE 0.093"	93
10-04-W163-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.062" 1'	317

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)