Method and system for controlling liquid crystal diffusion velocity and cell pressing device

Abstract

The invention discloses a method for controlling the liquid crystal diffusion velocity. According to the method, a vacuum chamber is closed, an upper substrate and a lower substrate are aligned, pressure corresponding to the current pressing position is applied according to an optimal position-pressure curve along with the change of the pressing position of the upper substrate to achieve cell pressing, and then coarse adjustment is carried out on the liquid crystal diffusion velocity; air with the optimal diffusion temperature is added into the vacuum chamber to achieve cooling, and then fine adjustment is carried out on the liquid crystal diffusion velocity. In a cell pressing process, pressure is adjusted according to the pressing position of the upper substrate, the liquid crystal diffusion velocity is then controlled, and liquid crystal is diffused fast under the action of the pressure; the vacuum chamber needs to be opened when the liquid crystal is diffused to a position close to frame sealing glue, the diffusion velocity is reduced by adding the air with the optimal diffusion temperature to achieve cooling, then fine adjustment is carried out on the liquid crystal diffusion velocity, the liquid crystal is prevented from being diffused to the position of the frame sealing glue to react with the frame sealing glue to cause glue breaking, and then liquid crystal leakage is avoided.

Description

Technical field [0001] The present invention relates to the field of display technology, in particular to a method, a system and a cell pressing device for controlling the diffusion speed of liquid crystal. Background technique [0002] The vacuum cell pressing process is an important step in the liquid crystal panel production process. It needs to be aligned and pressed in a closed vacuum chamber, and the array substrate (Thin Film Transistor, TFT substrate) and Color film substrate (Color Filter, CF substrate), the upper plate and the lower plate move towards each other to perform box alignment. One Drop Filling (ODF) liquid crystal molecules are injected on the CF substrate, frame sealant is coated around the TFT substrate, and the TFT substrate and the CF substrate are compressed in a vacuum chamber to form a liquid crystal display panel. [0003] After the TFT substrate and the CF substrate are pressed against the cell, the liquid crystal in the liquid crystal cell diffuses. ...

AI Technical Summary

Problems solved by technology

Before the cell is aligned, the liquid crystal dropped on the substrate is not easy to spread due to the effect of surface tension, and the diffusion speed is very slow

After the box is aligned, the distance between the two substrates becomes smaller due to pressing, which is generally 3.5um. Due to the pressure during the pressing process, the diffusion speed of the liquid crystal will also be accelerated. If the diffusion speed of the liquid crystal is too fast, edge defects will be formed. , even when the liquid crystal diffuses and the sealant has not been cured, the liquid crystal will diffuse to the position of the sealant, chemically react with the sealant, and the phenomenon of glue breaking will occur, resulting in liquid crystal leakage

However, even if there is pressure during the pressing process, the speed of liquid crystal diffusion will be accelerated, but if the temperature is very low, it will affect the viscosity coefficient of the liquid crystal and the speed of its diffusion. If the diffusion speed of the liquid crystal is too slow, it will cause the liquid crystal to disperse. Uneven, even localized bubbles

[0004] To sum up, whether the liquid crystal diffusion is too fast or too slow, it will have a great impact on the pass rate of the produced liquid crystal panel, and the yield rate is low

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