Those who have never been exposed to conductive shielding materials will definitely not know what they are. In fact, the main purpose of electrical shielding is to prevent high-voltage field strength from interfering with components. The design principle of electrical shielding is to use the shield to minimize the distributed capacitance between the interference source and the sensor, thereby reducing the impact of the interference source on the sensor.

What is conductive shielding?

Electrical shielding materials are various materials used between the heat source and the radiator. By removing the air between the heat source and the radiator, the heat of electronic equipment is distributed more evenly and the heat dissipation efficiency is accelerated. Generally, various thermal interface materials need to have good thermal conductivity and surface wettability.

Conductive shielding material

Conductive shielding materials mainly include the following aspects:

1. Conductive adhesive

A type of adhesive with conductive properties. Conductive adhesive is an adhesive that has certain conductive properties after curing or drying. It usually contains matrix resin and conductive fillers, that is, conductive particles, as its main components. Through the matrix resin The bonding effect combines the conductive particles together to form a conductive path and realize the conductive connection of the adhered materials

Since the basic resin of conductive adhesive is an adhesive, the appropriate curing temperature can be selected for bonding. At the same time, due to the rapid miniaturization and miniaturization of electronic components and the high density and high integration of printed circuit boards, development, and conductive glue can be made into a slurry to achieve very high line resolution. Moreover, the conductive adhesive process is simple, easy to operate, and can improve production efficiency. Therefore, conductive adhesive is an ideal choice to replace lead-tin soldering to achieve conductive connections.

2. Shielding

Conductive shielding materials mainly include conductive foam, conductive cloth, conductive double-sided tape, copper foil, aluminum foil, absorbing materials, etc. Let’s learn about the uses of these Products

❶ Conductive foam

Conductive foam is mainly divided into ordinary conductive foam and all-round conductive foam. It is made of elastic PU foam covered with textile fiber cloth containing metal plating. It has good elasticity and conductive properties and is widely used for EMI prevention and control of various electronic products.

Usage: Suitable for occasions where larger pressure cannot be provided, and plays a good electromagnetic sealing role. Such as electronic shielding chassis, laptop computers, mobile communication equipment, plasma displays, etc.

❷ Conductive cloth

Conductive cloth is mainly divided into grid cloth type conductive cloth and knitted conductive cloth. Plaid cloth has good conductivity, good shielding effect, and good processability. It is suitable for wrapping into various regular and irregular ordinary conductive foam materials. It is mainly suitable for ultra-thin shielding, conductive cloth foam, and conductive cloth tape. , conductive cloth pads, etc., have good anti-friction properties. Knitted conductive fabric has good friction resistance and is easy to be stamped and formed after wrapping. Its low cost and easy wrapping and molding properties make it the preferred material for I/O pads

Conductive cloth: Because the conductive cloth is a highly metallized nylon or polyester material base material, it has excellent conductive properties equivalent to metal, and also has good toughness and windability. Behind the conductive adhesive are various electronic appliances and communications Ideal material for equipment shielding, as well as for shielding and grounding of circuit boards or various surfaces.

Main categories of grid type conductive cloth:
Fabric Type: Plaid;
Metal plating: Nickel/Copper;
Conductivity: < 0.05 ohm/square;
Advantages: easy to form, strong shear resistance, friction resistance;

Characteristics of grid type conductive cloth:
1. Good electrical conductivity, surface resistance lower than <0.07 ohm/square.
2. Good shielding effect, the shielding efficiency can reach more than 60dB.
3. Good processability, soft texture, no burrs when cut, and easy to over-mold.
4. Suitable for wrapping into various regular and irregular ordinary conductive foam materials.
5. Mainly used in ultra-thin shielding, conductive cloth foam, conductive cloth tape, and conductive cloth gasket.
6. Good anti-friction performance, anti-friction times up to 500,000 times (ASTM-D4966);

Main categories of knitted conductive fabrics:
Fabric type: knitted conductive fabric;
Metal plating: Nickel/Copper;
Conductivity: < 0.07 ohms/square;
Advantages: low cost, suitable for I/O foam wrapping;

The following Bondller talks about the characteristics of knitted conductive fabric:
1. Good anti-friction performance, anti-friction times up to 400,000 times (ASTM-D4966).
2. Low cost, easy wrapping and moldability make it the preferred material for I/O pads.
3. It is easy to stamp and form after wrapping.

❸ Copper foil, aluminum foil

A material made of metal copper and aluminum that is directly rolled into thin sheets. Products used in electronics generally contain more than 99%. The material is soft, has good ductility, and has a silvery white or golden luster. However, it is easy to oxidize and darken in color, and it will change color when rubbed or touched, so good protective measures must be taken during processing.

Copper foil and aluminum foil are mainly used in copper strips for electrical conductivity, thermal conductivity, heat dissipation, magnetic shielding, antistatic and other purposes in the electronics industry. The hardness of the material is not high, usually below 0.2mm, which is very easy to process and easy to deform.

Applications of copper foil and aluminum foil:
It is mainly used to eliminate electromagnetic interference EMI and isolate the harm of electromagnetic waves to the human body. It is mainly used in computer peripheral wires, computer monitors and transformer manufacturers.

Uses of copper foil and aluminum foil: Suitable for various types of transformers, mobile phones, computers, PDAs, PDPs, LCD monitors, laptops, copiers and other electronic products where electromagnetic shielding is required.

❹ Absorbing material

Absorbing materials are mainly divided into iron oxide absorbing materials, metal powder absorbing materials, nano-absorbing materials, and optically transparent absorbing materials. It was first used in the field of military stealth, and has become more and more widely used this year. Absorbing materials were first used in the field of military stealth. In recent years, they have become more and more widely used in our lives.

Principle of absorbing materials: Absorbing materials are materials that can absorb electromagnetic wave energy projected onto its surface, and convert the electromagnetic wave energy into heat energy or other energy through the dielectric loss of the material.

The role of absorbing materials: mainly used to prevent interference, absorb electromagnetic waves, radiation, shielding, etc.;

Die-cutting processing: It is easy to produce delamination, dust, indentation, extrusion, scratches and other undesirable phenomena.

Characteristics of absorbing materials: high-performance sheet absorbing materials, high bonding strength for reliable installation, non-conductive for safer, outstanding mechanical properties for easier cutting.

Purpose: Suitable for the absorption of discrete noise from products such as PCB and RF signal sheets and FFC/FPC cable signal stations.

❺ All-round conductive foam

Omni-directional conductive foam: It is mainly composed of foam and conductive cloth wrapped around the foam. The whole body of the foam is equipped with metal substances that have been vacuum electroplated. It has low cost and good three-dimensional shielding effect. , able to exert excellent protective properties like metal.

Features: good shielding effect, good electrical conductivity, high friction resistance, flame retardant and thermal conductivity.

Purpose: Adapted to the shielding of various computers, TVs, notebooks, card readers and other products.

4. What are the applications of conductive shielding materials

Conductive shielding materials are used in communication equipment, network terminals, data transmission, LED, automobiles, electronics, consumer electronics, medical equipment, military, aerospace.

Through the above analysis, everyone should have a certain understanding of conductive shielding materials. If there is anything unclear, you can contact Guangdong Hangbang Co., Ltd. for communication.