RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
040R510-024000 Orbel	GASKET FABRIC FOAM RECTANGULAR 0	99
WS-4420-01-A 3G Shielding Specialties	CONDUCTIVE FOAM EMI GASKET	6
67B3G3006010010R0C Laird - Performance Materials	SP,CON,AU,TNR 10X3X6MM	0
4A66PA51H01800 Laird - Performance Materials	GASKT FAB/FOAM 12.7X457.2MM BELL	0
0097055002 Laird - Performance Materials	FINGERSTOCK BECU ALLOY 6X609.6MM	373
WS-3305-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .325WX.196HX24L	89
19-04-20581-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.053" 1'	187
0097057602 Laird - Performance Materials	FINGERSTOCK BECU 9.65X406.4MM	0
3021717 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	1
WS-3175-KR-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.375HX24L	13
4742PA51G01800 Laird - Performance Materials	GSKT FAB/FOAM 3.8X457.2MM DSHAPE	0
WS-4510-01-A 3G Shielding Specialties	CONDUCTIVE PE FOAM EMI GASKET	6
0077011002 Laird - Performance Materials	GASKET BECU 8.26X406.4MM	0
1565322-1 TE Connectivity AMP Connectors	SHIELD FINGER 1608	97248
4080PA51G01800 Laird - Performance Materials	RECTANGLE	0
1551575-5 TE Connectivity AMP Connectors	PRE-LOADED SPRING FINGER 3MM	36417
4242PA51G01800 Laird - Performance Materials	GSKT FAB/FOAM 6.4X457.2MM DSHAPE	98
2108614-5 TE Connectivity AMP Connectors	2.7H SPRING FINGER W/EMBOSS	23377
19-04-16162-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.100" 1'	70
331031271520 Würth Elektronik Midcom	CONTACT FINGER EMI SMD	6045

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)