Overview of Comprehensive Analysis and Application of FPC Electromagnetic Shielding Film

    Electromagnetic shielding filmIt is to stick metal foils with different thicknesses on the upper and lower surfaces of the film to form a shielding layer, which can effectively prevent the propagation of electromagnetic waves.
There are three main methods for its production: (1) conductive thin film, (2) conductive adhesive film, and (3) metalized porous film.

The following will introduce their production methods and applications:

1. Conductive film: It is formed by coating a layer of metal foil on a thin film, using the metal foil as the base film, attaching a conductive film on the base film, then attaching conductive ink or coating conductive substance on the film, and finally baking and curing it.

2. Conductive adhesive film: It is made by coating conductive adhesive on a base film and has good conductivity and thermal conductivity. Its resistance value is generally 25 Ω -10 Ω.

3. Metallized porous film: It is made by rolling metalized porous film onto a base film, and has good conductivity, thermal conductivity, and corrosion resistance.

The difference between metalized porous film and metalized thin film:

① Different resistance values: 25 Ω -10 Ω for metalized porous film and 50 Ω -10 Ω for conductive adhesive film;

② Different surface resistance:Metalized porous filmThe surface resistance is 200-1000 Ω/cm;

1、 Overview

The usage environment of electromagnetic shielding film is: temperature 0 ℃~50 ℃, relative humidity<30%. During production and processing, it is required to be free of dust, corrosive gases, and places with chemical corrosion.

Electromagnetic shielding film is mainly used in fields such as electromagnetic shielding, high-frequency communication equipment, communication power supply, radar interference suppression, and electromagnetic protection.

Applications: Antennas, RF modules, communication base stations, communication power supplies, radars, etc.

2、 The use of FPC electromagnetic shielding film:

1. Can serve as a flexible layer for FPC, enabling the installation and assembly of FPC and circuit board;

2. As a protective layer for the circuit board, to achieve the connection between the circuit board andConductive filmStrong adhesion to achieve good protection;

3. Can serve as an insulating material between circuit boards and electronic components, providing isolation and preventing interference from internal circuits;

4. It can be used as an electromagnetic shielding layer to reduce the impact on the circuit by reducing the energy generated by the propagation of electromagnetic waves in the circuit.

5. Has good resistance to electromagnetic interference. When there is no conductive film in the shielding room, electromagnetic waves can freely propagate inside the room, while without a shielding film, they can only propagate outward. Therefore, it is required that the shielding room has good anti-interference ability.

6. Has good electrical insulation performance;

7. Can be used as a circuit protection material;

8. Has good weldability.

3、 Compared with traditional electroplating technology, the performance advantages of FPC electromagnetic shielding film are as follows:

① Has good conductivity and thermal conductivity, improving the electrical performance of the circuit board;

② Low surface resistance effectively prevents the propagation of electromagnetic waves and improves the reliability of the circuit board;

③ It can prevent corrosion and oxidation of circuit boards caused by oxygen, water, and microorganisms in humid air, and improve the service life of circuit boards;

④ Has good insulation properties and good compatibility with other metals.

4、 What are the processing methods for electromagnetic shielding film?

There are three main methods for processing electromagnetic shielding films:

1. Using PET as the substrate, an electromagnetic shielding film is obtained by chemically plating copper or aluminum onto PET.
   

2. Using copper foil and aluminum foil as substrates, the shape is processed through laser engravingElectromagnetic shielding film.

According to different technical parameters, electromagnetic shielding films are also classified into different categories such as low impedance, high frequency, low frequency, multi-layer, and single-layer. Different technical parameters result in different purposes.

5、 Shielding film materials and application scope

The main materials used for FPC electromagnetic shielding film are copper alloy (18-60%) and tin (10-20%), and their material properties are as follows:

1. Copper alloy: high conductivity, melting point of 1060 ℃;

2. Tin: with a melting point of 2050 ℃ and low thermal conductivity (0.2-0.4W/m2K), it can suppress the thermal expansion of metal materials and reduce stress-strain;

3. Alloy can be used as an electrical insulation layer, but it is generally not suitable for making FPC because of its difficult processing and high cost.

FPC electromagnetic shielding film is widely used in fields such as mobile phones, laptops, digital cameras, and household appliances.