| Popis: |
Nowadays, conventional glass processing techniques, such as “score and brake” method, are being replaced by laser-based techniques. Precision, speed and quality makes laser glass processing a very attractive technique for industry. However, new laser-based techniques have to be validated in respect to conventional processing. For this we introduce comparative investigation of free glass processing techniques – rear side laser cutting, laser-based and mechanical dicing. Local weakening of the material and mechanical separation is a highly efficient two-step glass cutting approach. Material modification can be introduced by laser or mechanically. However, when complex shape cutting is required rear side laser cutting can offer much more flexibility. Glass is a brittle material, therefore generation of micro-cracks during processing is inevitable. Such side-effects can influence processed surface quality and material flexural strength. Rear side glass cutting experiments were carried out by tightly focusing the laser beam on the sample back-surface. Nanosecond laser pulses with wavelength of 532nm were used. In the case of laser glass dicing process, Bessel beam was introduced to form elongated modifications in glass. High pulse energy sub-nanosecond laser at 1064 nm wavelength was introduced. For mechanical processing, the conventional “score and break” method was used without any additional post processing. In all cases surface chipping was introduced. There was no significant difference in terms of micro-crack size for rear side cutting and mechanical dicing techniques. However, sample resistance to mechanical load was higher for mechanical processing. In this work, in-depth investigation of these effects will be introduced. |
