Ultra-thin glass has become a necessary basic material for flat panel display products because of its excellent thermal stability, chemical stability and optical properties. In order to meet the requirements of high performance flat panel display, the quality requirements of ultrathin glass, especially the surface roughness requirements are extremely strict.
At present, surface polishing technology is usually used to meet the requirements of surface quality and machining precision of ultra-thin glass. However, ultra-thin glass is difficult to process because of its high hardness, easy to be broken in processing and high polishing quality requirements, which is a technical difficulty for industrial production.
Ultra-thin glass is a brittle material, so it is different from the traditional plastic machining methods such as turning, grinding and milling of metal materials when polishing. It is easy to break in the process of precision machining, and it is difficult to realize the precision polishing of the glass surface. Therefore, the polishing of ultra-thin glass is based on the brittle-plastic transformation mechanism of hard and brittle materials. According to the different polishing principles and polishing methods, it can be divided into two categories, namely contact polishing technology and non-contact polishing technology.
Non-contact polishing technology is generally ion beam and electron beam polishing, which requires high technical operating environment and incomplete technical process, and cannot meet the overall polishing of large size workpiece. Therefore, from the point of view of improving the production and quality of ultra-thin glass, contact polishing technology is currently the absolute advantage.
Contact Polishing technique means to achieve polishing effect by the relative friction between the polished piece and the polished glass. For ultra-thin glass, the polishing technique is mainly Chemical Mechanical Polishing (CMP). CMP technology is considered to be the most effective technology for polishing ultra-thin glass because of its high polishing efficiency, small environmental pollution, mature technology, simple operation and low cost. Among them, polishing fluid and polishing pad are the core parts of polishing system, whose material determines the final machining quality.