25
Dec
Driven by modern technology, display devices such as smartphones and tablets are becoming thinner and more portable. The realization of these features is inseparable from the support of display glass panel thinning and polishing technology. Display thinning is to remove excess materials through etching and other means to make the screen reach the ideal thickness; while polishing further processes the surface of the thinned glass panel to make it as smooth as a mirror. The close cooperation of these two technologies can greatly improve the visual effect of display devices.
At present, the specific application of polishing is mainly focused on the surface treatment of glass surface, especially after the thinning step, because the most advanced thinning technology cannot make the glass surface 0 concave points. In order to maximize the yield of the whole plate, polishing has become a necessary process. It can repair some defects that appear or cause during the thinning process of the substrate, such as scratches and concave and convex points, and improve the surface finish and flatness of the glass substrate to make it smooth as a mirror.
It can be said that the polishing step is crucial to the final display effect of the display, because any tiny surface defects may affect the distribution and performance of the liquid crystal layer or the luminescent material.
(1) Preliminary polishing glass panel
Purpose: Remove fine scratches and residual defects left after fine grinding.
Process parameters:
Speed: Medium (about 300-600 rpm);
Pressure: Moderate to ensure that the glass does not overheat or generate stress;
Time: Depends on the surface roughness, usually 10-20 minutes.
(2) Fine polishing glass panel
Purpose: Improve the finish and obtain a highly transparent surface.
Process parameters:
Speed: Low speed (about 200-400 rpm);
Polishing liquid: Use finer particles of cerium oxide polishing compound and maintain uniform supply;
Time: 5-15 minutes, depending on product requirements.
(3) Rinse and dry
Purpose: Remove polishing liquid residue and prevent contamination.
Process:
Rinse with pure water or deionized water;
Airflow drying or vacuum drying to avoid surface water marks.
4. Key control points of polishing glass panle
Polishing temperature:
Excessive temperature will cause stress changes on the glass surface, resulting in deformation or microcracks;
Usually controlled below 40°C, achieved through cooling water circulation.
Polishing pressure: Uneven pressure will cause uneven surface and needs to be monitored in real time. Polishing liquid circulation: Ensure uniform concentration and sufficient flow of polishing liquid throughout the process.
According to the requirements of polishing operation, polishing consumables can be divided into: polishing pad (Polishing PAD), adsorption pad (Back PAD) and polishing powder (Polishing Powder)
1. Polishing PAD
It is used to carry polishing liquid while assisting in grinding and polishing glass. Different guide grooves are opened according to the needs of polishing to enhance the fluidity of the polishing liquid and avoid scratching the glass surface. As the use time increases, impurities gradually accumulate in the holes and grooves, and proper regular repair is required. At present, cerium oxide polishing pads are mainly used in TFT-LCD panel glass polishing.
2. Adsorption pad
According to the needs of polishing and adsorption panel glass, polyurethane foaming technology is used to form a follicle-like breathable structure in the polyurethane cortex. During the polishing process, the air in the follicle pores in the adsorption pad area of the panel glass is discharged under a certain pressure, thereby forming a vacuum to adsorb the polished glass.
3. Polishing powder
Since polishing products are mainly made of glass, cerium oxide polishing powder is generally used in the thinning industry. Its main component is cerium oxide, which is used to contact and cut the glass surface to remove trace amounts of glass.
Moresuperhard have rich experiences in alpping and polishing glass panel and we can provide quality polyurethane polishing pad and cerium oxide polishing compound.
