The folding cell phone comes with polyimides that matter

- Feb 27, 2019-

In October and November, the two companies unveiled phones with foldable screens.Unlike ordinary "hard" smart phones, foldable mobile phones use flexible display touch screen, consumers can easily bend and twist!

An analysis report pointed out that the flexible display screen is mainly used Polyimide (PI) instead of glass to do the substrate, so that the screen becomes flexible, hard screen for soft screen.

Polyimide (PI) is a kind of macromolecular polymer with cyclic imide groups in the molecular chain.It has excellent high temperature resistance, low temperature resistance, high strength and high modulus, high creep resistance, high dimensional stability, low thermal expansion coefficient, high electrical insulation, low dielectric constant and low loss, radiation resistance, corrosion resistance and other advantages.

At the same time, it can be processed into polyimide film, high temperature resistant engineering plastics, matrix resin for composite materials, high temperature resistant binder, fiber and foam, etc.

In recent years, polyimides have been studied, developed and utilized in many countries and listed as one of the "promising engineering plastics in the 21st century *".Due to its excellent performance, also known as the "problem solving expert", it is generally believed that "there will be no * microelectronics technology without polyimide".

Polyimide products to film, coating, fiber, engineering plastics, composite materials, adhesives, foam plastics, separation film, liquid crystal orientation agent, photoresists, etc., can be used in aerospace, electrical insulation, liquid crystal display, automotive medicine, atomic energy, satellites, nuclear submarines, microelectronics, precision machinery packaging.

Among them, polyimide film is polyimide series of products * early application, * for mature products.Polyimide films below the electronic level have achieved self-sufficiency in China, and the polyimide film market at the electronic level and above is still mainly Shared by overseas companies.

High-end polyimide film technology is still a few foreign enterprises monopoly

With the rapid development of flexible display screen, the market of high-end electronic polyimide film will be in the period of rapid expansion.The global polyimide thin film market was $1.52 billion in 2017 and is expected to reach $2.45 billion in 2022, according to MarketsandMarkets.

Polyimide technology is an oligopoly in the world.Polyimide film is well developed and there are many technology giants, but polyimide film still belongs to the high technology barrier industry.

At present, the global production capacity is still mainly monopolized by a few foreign companies, including dupont, Kaneka, SKPI and UBE.

In its earnings report for the second quarter of 2018 (as of June 30, 2018), ube noted that the company's net sales of PI in the second quarter of this year achieved strong growth compared with the same period of 2018, thanks to the reconstruction of its polyimide business, mainly benefiting from the growth of the OLED flexible display screen market.The company will also develop new PI film brands to increase the market share of circuit boards (FPC) and expand the sales of double-sided COF films.

China's polyimide import dependence reached 41.6%

China is not late in the industrialization of polyimide film. As early as in the 1970s, the research on the manufacturing technology of polyimide film was organized by the former first machine department.However, due to various reasons, the manufacturing technology of high performance polyimide film in China has been hovering at a low level.

In the late 1990s, along with the rapid development of the ultra-large integrated circuit manufacturing and packaging industry and the special power and electric appliance industry, the lack of high-performance polyimide film materials has become a bottleneck that seriously restricts the development of China's high-tech industry.

In the face of the urgent scientific and technical problems of polyimide films in China, the institute of chemistry of the Chinese academy of sciences, under the support of * national development and reform commission * high-tech industrialization project, has cooperated with shenzhen ruihuatai film technology co., ltd. since 2003 and started to devote itself to the research of high performance polyimide film manufacturing technology.

Through nearly eight years of efforts, we have mastered the key technology from key resin preparation to the stable process of continuous bi-directional stretch polyimide film production, and mastered the high performance polyimide film manufacturing technology with independent intellectual property rights.

On this basis, China has established a large-scale * high-performance polyimide film production base in 2010. A total of 11.8 billion yuan has been invested in * phase project construction, and 3 high-performance polyimide film continuous production lines with a width of 1200mm have been completed, with an annual capacity of 350t at full load.The completion and operation of the production base broke the monopoly of foreign manufacturers in the field of polyimide film materials and accelerated the localization process of polyimide film in high-end applications such as aerospace and solar energy