RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
0097053602 Laird - Performance Materials	GASKET BECU 17X609.6MM	1968
0097094102 Laird - Performance Materials	FINGERSTOCK BECU 5.1X609.6MM	0
4211PA51G01800 Laird - Performance Materials	RECTANGLE	0
0077001202 Laird - Performance Materials	GASKET BECU ALLOY 8.1X609.6MM	58
0077004202 Laird - Performance Materials	GASKET BECU 7.11X18.54MM	0
0097098302 Laird - Performance Materials	CARD GUI CLIPON BECU 2.03X9.53MM	9300
4629PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 10X457.2MM RECT	0
3020607 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	97
2040852-1 TE Connectivity AMP Connectors	SHIELD FINGER 0820 N-B WITH SE	159525
3021004 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	74
0077005617 Laird - Performance Materials	FINGERSTOCK BECU 8.1X406.4MM	0
4220PA51H01800 Laird - Performance Materials	GASKET FAB/FOAM 5.1X457.2MM RECT	5499
4212PA22101800 Laird - Performance Materials	GASKET FAB/FOAM 4.95X457.2MM SQ	0
37-131-1018-02400 Parker Chomerics	SOFT SHIELD 3700 EMI 1018 24"	896
10-04-6386-6502 Parker Chomerics	CHO-SEAL 6502 NI/AL 0.040" 1'	489
1551631-5 TE Connectivity AMP Connectors	1SHIELD FINGER, LOOSE PIECE	6458
5401-0005-90-300 Leader Tech Inc.	NI/C FILLED SILICONE 25FT ROLL	0
S7251-45R Harwin	RFI SHIELD FINGER AU 1.5MM SMD	2534
0097091502 Laird - Performance Materials	FINGERSTOCK BECU 11.43X381MM	0
4787PA51H01800 Laird - Performance Materials	GSKT FAB/FOAM 6.4X457.2MM DSHAPE	508

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)