RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
30512 Würth Elektronik Midcom	CONDUCTIVE NI/CU GLASS SLEEVE 1M	34
38401307 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	2
3021313 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	88
3851060 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	50
3020202 Würth Elektronik Midcom	GASKET FABRIC/FOAM 2MMX1M SQ	54
38401308 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
3021015 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	17
303076048 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	100
3029040030025 Würth Elektronik Midcom	WE-SMGS SURFACE MOUNT SOLDERABLE	4786
30205005 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	146
3023002 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	72
30308055 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	28
3030403 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	77
38401108 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
38401102 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	3
331161452070 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	392
3021504 Würth Elektronik Midcom	GASKET FABRIC/FOAM 15MMX1M RECT	19
38401306 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
38401003 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
3021310 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	78

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)