RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
S7061-42R Harwin	RFI SHIELD FINGER AU 5.5MM SMD	0
3021305 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	215
303035015 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	53
1053840002 Woodhead - Molex	SPRING CONTACT 0.70MM - 1.10MM H	5635
3023502 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0
0077009702 Laird - Performance Materials	GASKET BECU 15.24X406.4MM	0
38401301 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	16
0097055802 Laird - Performance Materials	FINGERSTOCK BECU 2.79X609.6MM	0
0097064502 Laird - Performance Materials	FINGERSTCK BECU ALY 5.33X609.6MM	456
77-12-3176-02400 Parker Chomerics	SOFT SHIELD 3500 EMI 3176 24"	44
24B13-BFA024000T Orbel	FINGER STOCK BECU ADHESIVE MOUNT	99
30M03-BFA024000T Orbel	FINGER STOCK BECU TWIST SERIES S	95
30210005 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	123
0097013502 Laird - Performance Materials	FINGERSTOCK BECU 7.11X406.4MM	465
0097091602 Laird - Performance Materials	FINGERSTOCK BECU 11.43X381MM	0
2108610-5 TE Connectivity AMP Connectors	1.4H SPRING FINGER W/EMBOSS	532
3020302 Würth Elektronik Midcom	GASKET FABRIC/FOAM 3MMX1M RECT	599
5411-0003-40-300 Leader Tech Inc.	M83528/011D003, AG/AL FILLED FLO	0
4060PA51G01800 Laird - Performance Materials	D-SHAPE	16
4184PA51G01800 Laird - Performance Materials	GASKT FAB/FOAM 3.8X457.2MM DSHAP	0

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)