RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
3020505 Würth Elektronik Midcom	GASKET FABRIC/FOAM 5MMX1M SQ	162
3029040030030 Würth Elektronik Midcom	WE-SMGS SURFACE MOUNT SOLDERABLE	2204
3031008 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	5
30205015 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	36
302095095 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0
3021717 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	1
331031271520 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	6045
3851110 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	50
38401106 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
38401403 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	0
38401414 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
3021510 Würth Elektronik Midcom	GASKET FABRIC/FOAM 15MMX1M RECT	34
3020805 Würth Elektronik Midcom	GASKET FABRIC/FOAM 8MMX1M RECT	18
38401101 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	5
38111023 Würth Elektronik Midcom	GASKET FAB/FOAM 11.3MMX1M KNIFE	33
30508/1000 Würth Elektronik Midcom	WE-ST LEITENDES NI/CU GLASFASER-	0
331021483033 Würth Elektronik Midcom	WE-SECF SMT EMI CONTACT FINGER	4400

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)