Thermal stress analysis on laser scribing of glass

Abstract

In the laser scribing of glass a thermal stress is introduced into a glass substrate by means of a CO 2 laser irradiation. The glass substrate is then rapidly cooled down by water jet immediately after the irradiation. For the purpose of theoretical clarification of the factors ruling the scribable condition and the crack depth, scribable conditions were acquired in laser irradiation experiments using a soda-lime glass substrate having a thickness of 0.7 mm. Furthermore, the crack depth and the crack edge profile were observed for various values of the distance between the heating area and the cooling area. On the basis of the scribable conditions obtained from the experiments results, a thermal elasticity analysis was conducted by a finite element method. The following results were obtained. The scribable condition can be estimated from the maximum tensile stress in the cooling area and the maximum temperature in the heating area. The crack depth in laser scribing depends on the tensile stress in the cooling area and the compressive stress field immediately under the area.

Three-dimensional thermal stress analysis on laser scribing of glass

“…11 are shown in Fig. 14 [21]. Here again, the lower set of data corresponds to the maximum tensile stress calculations and the upper set of data corresponds to the maximum surface temperature.…”

Influence of glass substrate thickness in laser scribing of glass

“…3. For the glass thickness 0.7 mm, the experimental results from previous study [6,7] were shown again. For the glass thickness of 0.4 mm in Fig.…”

“…The same apparatus as in a previous study [6,7] was used. The glass substrate was fixed on vacuum suction stage.…”

“…The authors [6,7] conducted thermal elasticity analysis with a finite element method based on a laser scribe experiment using soda-lime glass with thickness of 0.7 mm, and proposed the following laser scribe mechanism. The glass surface is heated by laser irradiation and the heat is transferred from the surface to the interior of the glass ( Fig.…”

The effect of material thickness, laser power and cutting speed on cut path deviation in high-power diode laser chip-free cutting of glass

“…The x-component of the stress (s xx ) is obtained for all the FE models as this component plays a dominant role in mode-I crack propagation (tensile stress normal to the crack surfaces) [12,19]. Fig.…”