RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
38401411 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	3
0097061202 Laird - Performance Materials	FINGERSTOCK BECU 11.176X406.4MM	451
1674954-1 TE Connectivity AMP Connectors	ACCY SPRING SHIELD FINGER	49113
55-45007 Parker Chomerics	FINGERSTOCK 0.03X0.23X24"	124
4850-12-1212-0150 Parker Chomerics	SOFT SHIELD 4850 12"X12" 1.5MM	136
4212PA51H00570 Laird - Performance Materials	GK NICU PTAFG PU V0 SQ	0
10-04-1687-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.070" 1'	52
1857724-4 TE Connectivity AMP Connectors	SHIELD FINGER	23693
5401-0006-76-300 Leader Tech Inc.	NI/C FILLED SILICONE 25FT ROLL	0
303076016 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	101
0097064602 Laird - Performance Materials	FINGERSTOCK BECU 7X406.6MM	0
0077005302 Laird - Performance Materials	GASKET BECU 8.1X37.57MM	0
3022010 Würth Elektronik Midcom	GASKET FABRIC/FOAM 20MMX1M RECT	88
07-0202-11053 Parker Chomerics	POLA SPONGE STRIP 11'X0.5X0.062"	9
5411-0001-60-300 Leader Tech Inc.	NI/C FILLED SILICONE; 0.125" OD,	6
4225EB50600313 Laird - Performance Materials	IO NICU MESH PU NR REC	0
4379PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 14.33X457.2MM BELL	0
0097095102 Laird - Performance Materials	FINGERSTOCK BECU 15.82X381MM	0
0097061902 Laird - Performance Materials	FINGERSTOCK BECU 11.176X406.4MM	0
0077001002 Laird - Performance Materials	GASKET BECU ALLOY 8.1X406.4MM	378

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)