Product Code: ICA12_P152

Suitable Processing Conditions Determined from the Standpoint of Residual Strain in Laser Scribing of Glass
Authors:
Keisuke Yahata, Management of Industry and Technology, Osaka Univ.; Suita Japan
Etsuji Ohmura, Management of Industry and Technology, Osaka Univ.; Osaka Suita Japan
Seiji Shimizu, Mitsuboshi Diamond Industrial Co., LTD.; Osaka Suita Japan
Masanao Murakami, Mitsuboshi Diamond Industrial Co., LTD.; Osaka Suita Japan
Presented at ICALEO 2012

Laser scribing is one of non-contact pre-processing for division of glass. A shallow crack which is origin of the division is formed, utilizing thermal stress caused by heating with the laser beam and by cooling with the water jet. Microcracks can be avoided, resulting in higher edge strength of divided glass. However, it has been cleared by our previous study that even low external load on the laser beam irradiated area sometimes allows formation of secondary cracks because of the residual strain. In this study, we have conducted the laser scribing experiments under a variety of the laser beam shape, the laser power, and the scanning velocity, and then examined in which case the secondary cracks are formed. In order to clarify the dominant factors of formation of the secondary cracks, we have conducted a thermo-elastic analysis by FEM. As a result, it was found that secondary cracks are generated in the case where the maximum shear stress at the glass surface exceeds a threshold during the heating with the laser beam. Therefore, the suitable processing conditions without the formation of the secondary cracks can be determined by comparing the results of the present analyses with the experimental results.