Polyimide Film: Definition, Properties, Uses

What is Polyimide Film?

Polyimide Film is the best filmic insulation material in the world, it consists of Pyromellitic dianhydride (PMDA) and diamino-diphenyl ether(DDE) in strong polar solvents by condensation and re-cast film made by the imidization. Being named as “Golden Film”, polyimide film with excellent performance, such as high temperature and low temperature capabilities, electrical insulating properties, cohesiveness, radiation resistance, media resistance, good chemical stability and self-extinguishing etc. It can be used long-term where the temperature ranging from -269 ℃ ~ 280 ℃ and short-term up to a high temperature of 400 ℃. Fire rating UL94 V-0, environmental protection without halogen, heavy metals and other restrictions on organic matter content have reached the national environmental standards. In addition, its surface (side) has a unique roughening process, which can improve product composite bonding capacity, and with a very significant improvement of adhesion of other bonding process in the same condition.

Main properties of Polyimide Films

Excellent heat resistance: The decomposition temperature of polyimide films generally exceeds 500 ° C, sometimes even higher. It is one of the highest thermal stability of known organic polymers.

‌Excellent mechanical properties: The tensile strength of the unreinforced matrix material is more than 100MPa. The tensile strength of some types of polyimide films such as Kapton can reach 170MPa, and Upilex S can reach 400MPa. The elastic modulus of polyimide fiber can reach 500MPa, second only to carbon fiber.

‌Good chemical stability and moisture and heat resistance: Polyimide film generally is not insoluble in organic solvents. It is resistant to corrosion and hydrolysis.

Good radiation resistance: The strength of polyimide film remains 86% after 5×10^9 rad dose radiation; The strength retention of some polyimide fibers after 1×10^10 rad fast electron radiation is 90%‌.

‌Good dielectric properties: The permittivity of polyimide film is less than 3.5. If fluorine atom is introduced into the molecular chain, the permittivity can be reduced to about 2.5, the dielectric loss is 10, the dielectric strength is 100 to 300kV/mm, and the volume resistance is 10^15-17Ω·cm‌.

Main uses of Polyimide Films

Electronic industry: Polyimide film is widely used in the electronic industry for heat insulation, flame retardant and protective layer of high performance electronic products. It can be used as an insulating layer for circuit boards, which provides electrical insulation and thermal stability‌.

Automotive industry: Polyimide films are widely used in the automotive industry to manufacture high-performance auto parts. It is resistant to heat, chemicals and wear. And it can be used as a packaging material for automotive batteries, sensors and electronic control units‌.

‌Medical field: In the medical field, polyimide films are used in the manufacture of medical diaphragms, artificial organs and drug delivery systems. It is biocompatible and corrosion-resistant and can be used to make medical devices and biomedical materials‌.

‌Aerospace industry: Polyimide films are widely used in the aerospace industry to manufacture high-performance spacecraft and aircraft components. It has the characteristics of light weight, high temperature resistance, corrosion resistance and high strength. It can be used to manufacture thermal insulation materials, anti-corrosion coatings and structural parts of spacecraft‌.