Laser zone texturing on glass and glass-ceramic substrates

A RF driven CO/sub 2/ laser is used to create laser bumps on glass and glass-ceramic substrates. The resulting bump height is found to be a function of laser parameters such as pulse width, spot size, and pulse energy. Composition, structure and chemical strengthening of the substrates also affect the laser bump topography. Laser bumps on glass-ceramic, non-strengthened glass, or strengthened glass substrates, all exhibit net volume gain. Possible mechanisms for the volume increase include density change due to glass quenched to a subcooled state and/or due to phase transition from the crystalline phase to the glass phase. Stress release may play a role in the case of chemically strengthened glass substrates. The tribological performance of laser texture on glass and glass-ceramic substrates again shows low stiction and low friction build-up.