Morrison & Foerster LLP
Laser-scribing of chemically strengthened glass
A method is disclosed for scribing a contained crack or vent in a chemically strengthened glass sheet. The glass has shallow surface regions under compressive stress, bounding a central region under tensile stress. The vent is formed by rapidly bulk-heating the glass, using radiation from a carbon monoxide laser, to a depth just below a surface compressive region and extending marginally into the tensile stress region then rapidly cooling the heated region with a water mist spray. The glass sheet can be subsequently divided along the vent by application of mechanical or thermal stress.
Coherent, Inc.
B C B B B C
B23K C03B B23K B23K B23K C03B
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Xinghua Walter R. John F.
Li Bosenberg Washko, Jr.