Study On CO₂ Laser Irradiation To Erase Glass Edge Micro-crack

Glass as a material has a long history. In people's lives it plays a decisive role. With the development of the electronics and solar industries, the glass has been applied in new areas. In these areas, the higher edge quality of the glass is required. Common methods of physical and chemical treatment can meet the requirement to some extent, but the effect is not very satisfactory. The processing will generate a lot of waste water, waste acid and other waste. This paper found a new method to eliminate the glass edge crack, remove the glass edge micro-cracks by laser radiation.In this paper, the continuous CO2 laser of 10.6μm was chosen as the laser resource. The mainly research object was 3mm ultra-white glass. The glass substrates were placed on the rate adjustable mobile platform, and the laser beam was perpendicular to the radiated surface. The four surfaces were processed in order. In order to understand the temperature changing during the process, ANASY software was used to build a finite element model. The temperature field in glass edge induced by laser radiation was simulated. Optical microscope was used to observe the micro-cracks of the glass edge before and after processing. A series of experiments with different parameters were done. The influences of different laser power, spot size and move speed on the experimental results were studied. Comparative experiment with 5mm glass was done. The main results and conclusions are as follows:1) Laser spot size determined how much power the glass substrate would accept per unit area. If the laser spot was too small, there would be small holes on the glass after processing. With increasing of the laser spot, this phenomenon can be improved. The optimum spot diameter of this experiment was 4mm～8mm.2) The laser power density had a very significant impact on the experiment result. The higher power density was, the greater the energy on the glass per unit area and the effects would be more obvious. But the laser power must be large enough that was no less than 15W When the laser power was large enough, and the laser power density greater than 100W/cm2, there was significant distortion on the glass edge. 3) The move speed of the sample determined the energy received by glass substrate per unit of time. Under certain conditions, the slower the move speed was the better the result would be. In this paper the best move speed was no more than 0.5mm/s.4)Through the comparative experiments with 5mm glass knew that the process parameters are different for glass of different thickness.