EMT steadily supplies optical PET base films that are highly challenging to produce and in high demand.Below is an introduction to the production and application of optical PET base films.
The production difficulty of optical PET base film applied in high-end display and microelectronics fields such as MLCC, polarizer, OCA is higher. The pre coating process requires high requirements, including good coating ability, precise surface control, and stable temperature shrinkage range. It is mainly used for preparing optical base films for liquid crystal display panels. Special function refers to the process of processing, coating, etc. on the basis of optical base film to endow the base film with specific functions in order to prepare optical functional films, such as OCA (special adhesive for transparent optical components), MLCC (multi-layer ceramic capacitors), polarizer release film, etc. The base film used in this process requires precise control of surface roughness, film alignment angle, cleanliness, and pre coating coating, making production more difficult.
The demand for optical base film in optoelectronic displays and MLCC is nearly one million tons. A single LCD display panel requires 10 optical PET base films. The LCD display panel is mainly composed of a liquid crystal panel and a backlight module. The LCD panel in LCD does not actively emit light and requires a backlight module to provide it with a light source. According to the structure shown in the figure below, the LCD backlight module consists of an upper diffusion film, an upper brightening film, a lower brightening film, a lower diffusion film, a reflective film, a light guide plate, and a photomask. The upstream raw materials for the brightening film, diffusion film, and reflective film are all optical base films, so a single LCD backlight module requires 5 pieces of optical PET base film. A single LCD panel requires two layers of polarizing film, namely two layers of protective film and two layers of release film,In addition, there is an ITO conductive film in the color filter structure, and the upstream is an optical PET base film, so a single LCD liquid crystal panel also requires 5 optical PET base films.
Three optical PET base films are required in a single OLED display panel structure. Unlike LCD, OLED has its own luminescent raw materials and does not require a backlight module. Its liquid crystal panel structure includes one polarizer and a reflective film, so a single OLED display panel requires three optical PET base films.
Figure：LCD & OLED Display Panel Structure Diagram
A single touch module requires 8 optical PET base films. Both ITO conductive film and OCA optical tape in the touch module require optical grade polyester base film. The touch module consists of 3 layers of OCA optical adhesive, 2 layers of ITO conductive film, and a glass or plastic panel; OCA optical adhesive consists of a light/heavy release film and an intermediate optical adhesive. OCA optical adhesive is a special double-sided tape with optical transparency features made by making optical acrylic adhesive without substrate, and then bonding one layer of release film on each of the upper and lower layers. The release film used for bonding is made of optical grade polyester base film as the raw material, so each OCA optical tape requires two optical grade polyester base films. At present, touch modules are required for products such as smartphones and tablets.
It is expected that by 2025, the global/domestic demand for optical PET in the field of optoelectronic displays may reach 4.4/300000 tons, of which the optical PET base film for polarizing films may reach 171000/119000 tons.
EMT possesses a mature optical film production ecosystem, with full-stack capabilities from R&D to mass production. Our automated production lines not only meet current market demands but also guarantee consistent and reliable high-quality deliveries.
Our company consistently provides high-performance optical PET base films. If you have any demand for such products, please feel free to contact our email: sales@dongfang-insulation.com。
Post time: May-13-2025
