What is the LCD panel, an introduction to the cutting process of the LCD panel

- Apr 20, 2020-

The LCD panel is an important part that determines the brightness, contrast, color and viewing angle of the LCD screen. The price of the LCD panel also directly affects the price of the LCD terminal product. The quality and technology of the LCD panel are related to the overall performance of the LCD. About 80% of the cost of an LCD monitor is concentrated on the LCD panel. LCD panel types can be roughly divided into three types: TN panel, VA panel, and IPS panel.


What is the LCD panel


Introduction of LCD panel cutting process


1. Cutter wheel cutting


Normal: Scribing with carbide wheels.


Disadvantages: Debris will be generated on the surface, which requires additional cleaning procedures.


2. Laser cutting


Spreading: Scan the material with a high-power laser beam. When the surface temperature of the material exceeds its softening temperature, the material begins to fuse and melt until it vaporizes.


Disadvantages: extremely high temperature, high thermal stress and residual stress generated will produce micro-cracks, molten material will remain inside the cut surface, and still need to be cleaned after cutting.


Difficulties in cutting LCD panel


The liquid crystal display panel is composed of two glass plates, and the interlayer is a crystal droplet about 5 microns thick. The liquid crystal display panel is an important component of the liquid crystal display. When manufacturing or using the liquid crystal display panel, there may be a liquid crystal display panel with a bad D gauge and a large-size panel that is scrapped. However, there are technical difficulties in cutting large-size LCD panels into small-size LCD panels:


1. After the bad glass in the original liquid crystal display panel is cut, there is liquid crystal leakage in the cut hole;


2. When cutting, the TFT crystal will be cut, resulting in a short circuit at the bottom of the cut, resulting in bad lines when the screen is displayed;


3. The glass in the original LCD panel already has a polarizer. Because of the existence of the polarizer, the cutter wheel cannot directly touch the glass surface. The polarizer needs to be removed and the glass can be exposed before cutting, but the polarizer is removed It will cause material waste, and it will also cause undesirable phenomena such as the formation of foreign objects on the glass surface by UV solid glue in the subsequent process.


Liquid crystal display panel cutting method and steps


(1) Cut the polarizer; first correct the slicing mold with scales on the slicing mold, adjust the position of the polarizer according to the cutting size of the LCD panel, set the spacing between the two blades of the slicing head and fix the card position, then polarize the LCD panel Cut the film, then tear off the polarized film that was cut off to expose the glass surface;


(2) Precise cutting; positioning; fix the LCD panel with the polarizer removed through the vacuum suction of the cutting platform, fine-tune the machine CCD to find and display the pixl unit image, make the cutting position avoid the TFT crystal position, and move the cutter head slightly Go to the pixl light-transmitting central area, form positioning coordinate parameters, save the coordinate parameters, and complete the positioning of the lower knife; set the cutting parameters; control the cutting parameters during the cutting process, so that the glass is in a natural fracture state after cutting, to prevent the liquid crystal from being cut by splitting Missing;


(3) Sealing and curing; the cut liquid crystal display panel is sealed with UV glue through a sealing carrier, and the cut is finished with UV glue, and the penetration time is 30-40s; after the penetration, the UV light is used for UV The sealant is fully cured;


(4) Inspection and testing; the liquid crystal display panel after the curing of the sealing is subjected to lighting test and inspection, and after trust, it is trusted to put in. Further, the interval between the two blades of the slicing head in the step (1) is 1.5-2.5 mm. Further, the cutting parameters in the step (2) include: a lower blade depth of 0.05-0.06 mm, a lower blade pressure of 0.6-0.8 Mpa, and a traveling speed of the blade of 300-500 mm / s. Further, the light energy of the UV irradiation lamp in the step (3) reaches 1800J / cm2 or more, and the lamp stay time is 2s or more. Further, the interval between step (2) and step (3) shown does not exceed 1 min.