Glass-based article with engineered stress distribution and method of making same
AssigneeCorning Incorporated
InventorsSumalee Likitvanichkul Fagan, William John Furnas, Ekaterina Aleksandrovna Kuksenkova
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Abstract
Disclosed herein are glass-based articles having a first surface having an edge, wherein a maximum optical retardation of the first surface is at the edge and the maximum optical retardation is less than or equal to about 40 nm and wherein the optical retardation decreases from the edge toward a central region of the first surface, the central region having a boundary defined by a distance from the edge toward a center point of the first surface, wherein the distance is ½ of the shortest distance from the edge to the center point.
Claims18
A method for processing a glass-based substrate comprising:
- pressing a glass-based substrate between two pressing surfaces, the glass-based substrate having a first surface and a second opposing surface;
- heating the glass-based substrate pressed between the two pressing surfaces such that the entire glass-based substrate is above a first temperature, wherein the first temperature is above the annealing temperature of the glass-based substrate;
- holding the glass-based substrate pressed between the two pressing surfaces at the first temperature for a predetermined time;
- and
- cooling the glass-based substrate pressed between the two pressing surfaces after the predetermined time such that the entire glass-based substrate is below a second temperature, the second temperature being below the strain point of the glass-based substrate, and during the cooling, an edge of the glass-based substrate is about 1° C. to about 12° C. cooler than a center of the glass-based substrate,
- wherein an optical retardation of the first surface of the glass-based substrate decreases from an edge of the glass-based substrate towards a central region of the first surface such that a maximum optical retardation of the first surface is at the edge.
A method for processing a glass-based substrate comprising:
- pressing a glass-based substrate having a first surface and a second opposing surface between two surfaces;
- heating the glass-based substrate pressed between the two surfaces such that the entire glass-based substrate is above a first temperature, wherein the first temperature is above the annealing temperature of the glass-based substrate;
- holding the glass-based substrate pressed between the two surfaces at the first temperature for a predetermined time;
- and
- cooling the glass-based substrate pressed between the two surfaces after the predetermined time such that the entire glass-based substrate is below a second temperature, the second temperature being below the strain point of the glass-based substrate, and during the cooling, a center of the glass-based substrate is about 1° C. to about 12° C. cooler than an edge of the glass-based substrate,
- wherein an optical retardation of the first surface of the glass-based substrate increases from an edge of the glass-based substrate towards a central region of the first surface such that a maximum optical retardation of the first surface is at the center.
Dependencies are inferred from the claim text.