RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
1565158-1 TE Connectivity AMP Connectors	SHIELD FINGER 1511	33771
0097091002 Laird - Performance Materials	FINGERSTOCK BECU 15.82X381MM	0
4912PA51G01800 Laird - Performance Materials	GSKT FAB/FOAM 3.8X457.2MM DSHAPE	0
6-31CPG-BD-12 Leader Tech Inc.	COPPER BERYLLIUM FINGERSTOCK EMI	52
0097055102 Laird - Performance Materials	FINGERSTOCK BECU 4X609.6MM	259
0077011402 Laird - Performance Materials	GASKET BECU 8.26X368.3MM	0
38401102 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	3
10-04-W204-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.125" 1'	592
0077002602 Laird - Performance Materials	GASKET BECU 9.4X24.77MM	0
331161452070 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	392
0C97043802 Laird - Performance Materials	RFI EMI GROUNDING MATERIAL 25FT	0
S0961-46R Harwin	RFI SHIELD CLIP MINI TIN SMD	4990
3021504 Würth Elektronik Midcom	GASKET FABRIC/FOAM 15MMX1M RECT	19
38401306 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
67B3G2504807010R0B Laird - Performance Materials	SP,CON,3,AU,TNR 7X2.5X4.8MM	0
7125-06250875-71 Leader Tech Inc.	.125" T X .65" ID X .875" OD KNI	85
4053PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 2.3X457.2MM DSHAPE	185
0077007102 Laird - Performance Materials	GASKET BECU 11.43X411.48MM	329
120220-0202 VEAM	UNIVERSAL CONTACT 1.8MM SMD	712139
19-04-27546-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.062" 1'	471

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)