The "softness" of flexible display screens

After decades of development, the number of LED displays has been increasing. The traditional LED display is a bit too saturated, and the market growth is weak. A very important reason is that it can not meet the needs of some subdivision scenes, such as some buildings are not flat, or curved walls. If it is a traditional hard screen, the traditional led display is made with a hard PCB and a bottom case mask, which has no flexibility, or cannot be laid out with a large led screen, or needs to be cut corners, which not only increases the cost, but also The craftsmanship isn't perfect either.
Comparison of the characteristics of LED soft screen and conventional LED display

1. LED soft screen features:
Strong installation adaptability: It can realize all kinds of opposite sex, such as spherical, arc, etc., with good creativity and is not limited by application scenarios.
Cool: full transparent material optional, creative double-sided display, to achieve real 3D
Easy maintenance: the original LED embedded strip structure can realize fast maintenance on site;
Light weight: the weight is only 10kg/㎡, easy to install and transport the product, saving installation time and cost;
Thin: the thickness is only about 10mm, occupying a small space, saving installation and transportation space
High protection: The protection level is up to IP65, no fear of bad rain and weather, and can be used outdoors with confidence;
2. Conventional LED display features:

High brightness: outdoor brightness is greater than 8000mcd/m2, it is the only large display terminal that supports outdoor all-weather use; indoor brightness is greater than 2000md/m2;

Long life: LED life is up to 100,000 hours, this parameter generally refers to the design life, even if the brightness is dim;

Large viewing angle: The indoor viewing angle can be greater than 160 degrees, and the outdoor viewing angle can be greater than 120 degrees. The size of the viewing angle depends on the shape of the LED light-emitting diode;

The area of ​​the LED screen can be large or small, as small as less than one square meter, and as large as hundreds or thousands of square meters.

In the LED display large-screen market, it must be said that this 100 billion-level industry group is currently supported by "rigid" displays - and there is no shortage of curved screens. How do rigid display products realize large curved LED screen displays? The essence is that these large curved display screens do not require a large curvature. Regardless of whether it is a building exterior or an indoor application, the LED arc surface can be constructed by small modules in a way similar to "polyhedron". And because the curvature is not very large, the display effect is still satisfactory.

Therefore, if LED display products want to achieve "flexible" characteristics, it must first open up a new market: display engineering design that requires a large curvature. This often refers to creative commercial, cultural or advertising display products, rather than simple traditional "LED large screen application scenarios".

As the name suggests, a flexible screen is a soft screen, and its manufacturing principle is to use a flexible material (plastic) to replace a rigid display (glass, etc.). Due to the abandonment of rigid glass, production costs can theoretically be reduced. Materials that have been developed to replace glass substrates include PI plastics.

Compared with the easy forming characteristics of glass, the original state of PI material is liquid, and it needs a special process to convert it into the desired state of the screen film. Using glass as a mold, PI is evenly covered on the glass, and then peeled off after curing. It seems a simple step, but it requires complicated process tests to finalize mass production.

In addition to the difficulty of mass production of the flexible screen material itself, it is also a difficulty in packaging. Traditional OLED glass screen packaging, because glass is a rigid material, can be processed by reliable packaging; when packaging flexible displays, TFE technology needs to be used to prevent external pollution and water molecules from affecting the flexible screen through various means. cause damage.

The flexible screen also has shortcomings: 1. Due to the use of flexible substrates and packaging, it is easy to deform and lose the smoothness of the surface of the glass display, resulting in unevenness.

②Low melting point. Since the manufacturing process uses flexible materials, the low melting point of the flexible substrate is a big disadvantage.

③ Short life, water and oxygen are fatal to OLED screens, so the screen is easily damaged by water, and due to its packaging process, the flexible substrate is easy to penetrate water and oxygen, resulting in a series of chemical reactions inside, resulting in shortened screen aging life, Therefore, the laboratory data is unable to work continuously for more than 10,000 hours.

④The conductive film is easy to fall off. Due to the use of a flexible substrate with a low melting point, the conductive film plated at a lower temperature results in a low adhesion to the substrate, which is easy to fall off during long-term bending. show the problem. In addition, the difference between the thermal expansion coefficients of the substrate and the conductive film is too large, and when the external temperature changes too much, it is easy to cause the conductive film to detach.