RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
10-04-6386-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.040" 1'	313
WS-3330-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .315WX.315HX24L	98
3020701 Würth Elektronik Midcom	GASKET FABRIC/FOAM 7MMX1M RECT	100
2108611-5 TE Connectivity AMP Connectors	1.7H SPRING FINGER W/EMBOSS	83000
WS-3630-KB-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.200HX24L	100
38401404 Würth Elektronik Midcom	WE-EGS EMI ELASTOMER GASKET	13
CF710EA02541049 Laird - Performance Materials	GK, NICU,CF,V0 1X25.4X104.9MM	4
0077006202 Laird - Performance Materials	GASKET BECU 8.1X4.27MM	0
21B03-BFA000543N Orbel	FINGER STOCK BECU SLOT-MOUNT 0.1	99
3024502 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0
4548PA51G01800 Laird - Performance Materials	GSKT FAB/FOAM 6.4X457.2MM DSHAPE	0
55-72000 Parker Chomerics	FINGERSTOCK 0.22X0.6X15.75"	50
4120PA51H01800 Laird - Performance Materials	D-SHAPE	0
81-01-32AS1-2000 Parker Chomerics	FINGERSTOCK 0.22X0.6X18"	48
30B09-BFA024000T Orbel	FINGER STOCK BECU TWIST SERIES S	100
0077001702 Laird - Performance Materials	GASKET BECU 8.1X9.04MM	522
38008027 Würth Elektronik Midcom	GASKET FABRIC/FOAM 8MMX1M KNIFE	97
WS-3210-KD-2400 3G Shielding Specialties	FAB/FOAM GASKET .250WX.050HX24L	95
3020802 Würth Elektronik Midcom	GASKET FABRIC/FOAM 8MMX1M RECT	96
0097056702 Laird - Performance Materials	FINGERSTOCK BECU 18.29X609.6MM	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)