RFI and EMI - Contacts, Fingerstock and Gaskets

Image	Part Number	Description / PDF	Quantity	Rfq
	4243ABH1K00125 Laird - Performance Materials	GK NICU NRS PU V0 CSH	0
	4609PA51H01200 Laird - Performance Materials	GK NICU PTAFG PU V0 DSH	0
	0097063617 Laird - Performance Materials	NOSG,STR,SNB,CLO	0
	0078002417 Laird - Performance Materials	SLMT,2F,SNB,USFT	0
	0097055605 Laird - Performance Materials	TWT,STR,CDY,PSA,POR .070X.340X.1	0
	8417305762 Laird - Performance Materials	USRE,PU,AGNYLON,PSA,CTL 0.250X0.	0
	0097011517 Laird - Performance Materials	CSTR,STR,SNB	0
	4210AB51K01200 Laird - Performance Materials	GK NICU NRS PU V0 REC	0
	4609AB51K09600 Laird - Performance Materials	GK NICU NRS PU V0 DSH	0
	0095090100 Laird - Performance Materials	SSTK,STR,SS	0
	8402010540 Laird - Performance Materials	EMI/RF GASKET .187 DIA	0
	0078001919 Laird - Performance Materials	SLMT,4F,NIB,USFT	0
	4529PAH1K01800 Laird - Performance Materials	GSKT FAB/FOAM 10.67X457.2MM CFLD	0
	0097013721 Laird - Performance Materials	CSTR,STR,SU	0
	4164PA51H01200 Laird - Performance Materials	GK NICU PTAFG PU V0 REC	0
	8406011650 Laird - Performance Materials	ENSL,NEOSP,BECU,PSA,RL .375X.500	0
	29100012 Laird - Performance Materials	CA19/PSA A11659	0
	0078005617 Laird - Performance Materials	VSLMT,STR,SNB,USFT	0
	0097054001 Laird - Performance Materials	AP,STR,BF	0
	4208GR51H01533 Laird - Performance Materials	IO NICU PTAFG PU V0 REC	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)