RFI and EMI - Contacts, Fingerstock and Gaskets

Image	Part Number	Description / PDF	Quantity	Rfq
	0078002415 Laird - Performance Materials	SLMT,2F,ZNC,USFT	0
	4046AA51K01800 Laird - Performance Materials	GASKET FABRIC/FOAM 3X457.2MM SQ	0
	4548PA51H09600 Laird - Performance Materials	GK NICU PTAFG PU V0 DSH	0
	4283AB51K09600 Laird - Performance Materials	GK NICU NRS PU V0 DSH	0
	0077001017 Laird - Performance Materials	SLMT,STR,SNB	0
	8902-0122-42 Laird - Performance Materials	EGW,MON .250X.240X.500IN	0
	4315AB51K04800 Laird - Performance Materials	GK NICU NRS PU V0 REC	0
	67BSG2004507012R0B Laird - Performance Materials	SP,CON,S,AU,TNR	0
	4612PA51G00118 Laird - Performance Materials	GK NICU NRSG PU V0 REC	0
	8866-0126-72 Laird - Performance Materials	DSTRHOL,CUSTMATL 12.19X8.51X6.1X	0
	4245AB51K00670 Laird - Performance Materials	GK NICU NRS PU V0 REC	0
	4697AB22102600 Laird - Performance Materials	GK NICU PTAF TPE HB CSH	0
	8416-0230-21 Laird - Performance Materials	EMEM SIL ALEM SHT	0
	4202AE51H01800 Laird - Performance Materials	GK NICU PTAFG PU V0 DSH	0
	4701PA51G00958 Laird - Performance Materials	GK,NICU,NRSG,PU,V0,REC	0
	0097060617 Laird - Performance Materials	CLO,STR,DLN,SNB	0
	4215PA51H04800 Laird - Performance Materials	GK NICU PTAFG PU V0 REC	0
	8867-9147-92 Laird - Performance Materials	PSTRHOL,ECE092,PSA 7.4X2.4X1.6X0	0
	4283PA51G01200 Laird - Performance Materials	GK NICU NRSG PU V0 DSH	0
	8866-0130-72 Laird - Performance Materials	DSTRHOL,CUSTMATL 2.54X2.39X1.00X	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)