What is polyimide film
Polyimide film (PI film) is a high-performance organic polymer material that plays a key role in many high-tech fields
1. Composition and preparation process
Composition: Polyamic acid is usually obtained by condensation reaction of aromatic dianhydride and aromatic diamine, and then intramolecular cyclization is carried out through thermal imidization or chemical imidization to form a poly
Polyimide film (PI film) is a high-performance organic polymer material that plays a key role in many high-tech fields
1. Composition and preparation process
Composition: Polyamic acid is usually obtained by condensation reaction of aromatic dianhydride and aromatic diamine, and then intramolecular cyclization is carried out through thermal imidization or chemical imidization to form a polymer containing an imide ring, which is then used to make a thin film. Common raw material combinations, such as phthalic anhydride (PMDA) and diaminodiphenyl ether (ODA).
Preparation method: The solution casting method is commonly used. Firstly, polyamide acid is dissolved in a strong polar solvent to make a uniform solution. Then, it is cast into a film on a clean steel strip or glass substrate. After a series of processes such as heating, drying, and imidization, the film is gradually formed and solidified, and the finished polyimide film is obtained by winding.
2. Performance characteristics
High temperature resistance: With outstanding thermal stability, it can withstand temperatures of up to 260 ℃ for long-term use and over 400 ℃ for a short period of time. This allows it to maintain stable performance for a long time in high-temperature working environments without easily softening or deforming.
Good mechanical performance: high tensile strength, good toughness, outstanding tensile and bending resistance. Even after repeated bending and pulling, the film is not easily cracked or damaged, and has good durability.
Good electrical insulation: With relatively high insulation resistance, it can effectively block current in high voltage and high frequency electrical environments, prevent electrical accidents such as leakage and short circuits, and is an ideal electrical insulation material.
Strong chemical corrosion resistance: It has good resistance to common organic solvents, acids, and bases. Whether immersed in acidic solutions or in contact with various organic solvents, its chemical structure and properties are difficult to damage.
Low dielectric constant: The dielectric constant and dielectric loss are both at a relatively low level, which allows it to reduce signal attenuation and interference in electronic signal transmission applications, facilitating high-speed signal transmission.
3. Application Fields
Electronic appliances: It is a key substrate for flexible printed circuit boards (FPCs), which gives the circuit board bendable characteristics, making electronic products thinner, lighter, and more portable. FPCs inside devices such as smartphones, tablets, and smart wearables cannot do without it; It is also used for insulation wrapping of motors and transformers to ensure the safe operation of electrical equipment.
Aerospace: The insulation protection of internal circuit systems of aircraft, high-temperature insulation around engines, and structural components of aerospace equipment are all achieved through the high-temperature resistance, lightweight, and high-strength characteristics of polyimide films.
New energy vehicles: used in the drive motor and battery management system of new energy vehicles for wire insulation, electronic component packaging, and to cope with high temperatures, vibrations, and other complex working conditions of the vehicle.
Rail transit: responsible for the insulation material of the electrical system of high-speed rail, subway and other rail transit vehicles, resisting vibration, friction and temperature changes during operation, and ensuring driving safety