Coated polyimide film is now widely used in the electrical field: wire, coil insulation, flexible printed circuit board substrate, masking film, generator trunking, magnetic wire insulation, transformer and capacitor insulation and pressure sensitive tape Wait.
One of the important application areas is in electronics. With the rise and vigorous development of the IT industry, flat panel display industry, photovoltaic industry, etc., the development of related supporting materials and the increase in market demand will definitely be driven. Electronic engineering (electronic grade) polyimide film is an important raw material for printed circuit boards, integrated circuits, flat panel displays, solar cells, electronic labels, etc., and is increasingly playing an important role in the application of the above electronic products. . The reason is because it has the following characteristics:
(1) Excellent heat resistance. The differentiation temperature of polyimide generally exceeds 500 ℃, sometimes even higher, and it is one of the types of organic polymers with high thermal stability. This is mainly because the molecular chain contains a large number of aromatic rings.
(2) Excellent mechanical function. The tensile strength of the unreinforced matrix material is above 100MPa. The tensile strength of Kapton film prepared with homoanhydride is 170MPa, while that of biphenyl polyimide (Upilex S) can reach 400MPa. The elastic modulus of polyimide fiber can reach 500MPa, second only to carbon fiber.
(3) Excellent chemical stability and heat and humidity resistance. Polyimide materials are generally insoluble in organic solvents, resistant to corrosion and hydrolysis. Altering the molecular design can yield different types of structures. Some species can withstand 2 atmospheres, 120 ℃, 500h boiling.
(4) Outstanding radiation resistance. After 5×109rad dose radiation, the strength of polyimide film still maintains 86%; after some polyimide fibers are irradiated with 1×1010rad fast electron, the strength persistence rate is 90%.