What are the applications of colorless transparent PI film in the field of optoelectronics?
Polyimide material has excellent low temperature resistance, radiation resistance, dielectric properties and mechanical properties, low thermal expansion coefficient, non-toxic and self-extinguishing, can be used in the manufacture of films, coatings, advanced composite materials, fibers, engineering plastics, electro-optical materials, photoresists, etc., of which polyimide film is one of the indispensable materials in today’s electronics, microelectronics and aerospace industries, its excellent heat resistance and bendable flexibility make it an important material in flexible packaging and flexible optoelectronic devices. It has been the focus of research by scholars.
However, the traditional polyimide film generally belongs to the full aromatic group, and is generally prepared by diamine and dianhydride by polycondensation reaction to obtain prepolymer, and then prepared by imination treatment. The electronitization of diamine residues and the electron-absorbing properties of dianhydride residues lead to the movement of intramolecular charges, forming electron transfer complexes (CTCs), thereby low light transmittance, and the film shows characteristic yellow or brownish yellow, which greatly limits its application in the field of optics. At present, scholars at home and abroad inhibit the formation of CTC by introducing fluorine-containing groups, alicyclic structures, non-coplanar structures, meta-substitution structures, sulfone groups, etc. on the polyimide main chain, thereby improving the light transmittance of polyimide films and reducing the yellow index of the film.
Application of transparent PI
With the development of the times, the replacement of optoelectronic devices is getting faster and faster, and people have put forward higher and higher requirements for the performance of optoelectronic devices, such as lightweight, ultra-thinness and flexibility. This trend offers great opportunities for the development of colorless transparent polyimide optical films. Colorless transparent PI film has the advantages of light and thin, transparent, high temperature resistance and good processability, and can be used in various substrates such as flexible display devices and flexible solar cells, and has been widely used in the field of optoelectronics. In addition, colorless transparent PI film is also a key research material for flexible packaging in the future.
1. Flexible display device substrate
Flexible substrate is an important part of flexible display device, plays the role of structural support and providing medium for optical signal transmission, the characteristics and functions of flexible substrate largely determine the quality of flexible device. At present, there are three main substrates for flexible displays: thin glass, transparent plastic (polymer) and metal foil. Both transparent plastic substrates and thin glass have good light transmission, but transparent plastic substrates are also as flexible as metal foils. Therefore, the transparent plastic substrate is ideal for flexible displays. Flexible displays with plastic substrates have the advantages of thinness, lightness, and good flexibility, and have broad development prospects. Colorless transparent PI film has excellent thermal stability and mechanical properties, high tensile strength, in addition to the widely used polyethylene terephthalate (PET) film, PI film is considered by the industry to be one of the most suitable materials for flexible substrate.
2. Flexible thin-film solar cell substrate
Flexible thin-film solar cells are advanced batteries with excellent performance and low cost, which can be used in solar flashlights, solar backpacks, solar cars or integrated on roofs or exterior walls, and are widely used. Traditional thin-film solar cells are not adaptable to shape, and the preparation of thin-film solar cells on flexible polymer substrates can solve this problem and reduce the weight and cost of the battery. The colorless transparent PI thin film has excellent optical transparency and excellent high temperature resistance, and can withstand high temperatures above 450 °C during processing, which provides the possibility for the production of high-efficiency solar energy batteries.
3. Flexible packaging material substrate
Packaging refers to the packaging of integrated circuits with insulating materials to isolate the circuit from the outside world to prevent impurities in the air from corroding the circuit, and at the same time facilitate the installation and transportation of the circuit. At present, the development trend of optoelectronic devices is ultra-thin, lightweight and flexible, which requires corresponding high-performance flexible packaging materials. Traditional glass substrates are thick, large in quality and not flexible, and cannot meet the requirements of future flexible packaging materials. Colorless transparent PI film can meet the flexible requirements, and the transparent light weight, can withstand high temperature and pressure, so it is the first choice for flexible packaging substrates in the future.
Conclusion
Through molecular structure design, such as the introduction of fluorine-containing groups, lipid ring structures, non-coplanar structures, meta-substitution structures, sulfone groups, etc. on the main chain, or combining the above factors to play a synergistic effect, the optical properties of polyimide films can be effectively improved. While improving the optical properties of PI films, it is also necessary to take into account other properties of PI films, such as mechanical properties, dielectric properties and thermal stability. In addition, the nano-composite effect can reduce the thermal expansion coefficient of the film and improve the mechanical and heat resistance under the premise of maintaining the optical properties of the PI film.
Colorless transparent PI film is undoubtedly a new material with high technical content and high added value, and its excellent comprehensive properties make it an ideal choice for advanced optoelectronic devices. It is foreseeable that with the increasing demand for optoelectronic manufacturing, the research of colorless transparent PI film will receive more attention from the academic and industrial circles, and the colorless transparent PI film is facing huge development opportunities.
At present, colorless transparent PI films are very limited and expensive in the market, and are only used in high-end electronic products. Therefore, how to reduce the cost of colorless transparent PI film is worthy of in-depth study by the majority of material researchers.
Our 6FXY (CAS#65294-20-4) and 6FDA (CAS#1107-00-2) products, mainly used as PI transparent film, have been widely recognized by overseas customers. Welcome to contact us!
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Post time: Dec-07-2022