Enhanced strength of glass by combining redraw and chemical thinning processes
AssigneeCorning Incorporated
InventorsBethany Jon Alderman, Patrick Joseph Cimo, Kuan-Ting Kuo, Robert Lee Smith, III
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Abstract
A cover element for an electronic device that includes a glass element having a thickness from 20 μm to 125 μm, a first primary surface, a second primary surface, a compressive stress region extending from the first primary surface to a first depth, and a polymeric layer disposed over the first primary surface. Further, the glass element has a stress profile such that it has a bend strength of about 1850 MPa or more at a 10% failure probability, wherein the cover element is made by a multi-step method that employs a redraw thinning step and at least two chemical etching steps.
Claims20
A glass-based element comprising a bend strength of from about 1000 MPa to about 1800 MPa at a failure probability of 1% and an average thickness of less than 75 microns.
A method of making a glass-based element, comprising the steps of:
- redrawing a preform glass sheet to form a redrawn glass sheet;
- cutting the redrawn glass sheet to obtain a redrawn glass part, the redrawn glass part comprising a first surface and a second surface;
- in a first chemical etching step, contacting the first and/or second redrawn glass part surfaces with a first etchant to form a chemically etched redrawn glass part;
- subjecting the chemically etched redrawn glass part to an ion exchange step to form an ion-exchanged redrawn glass part, the ion-exchanged redrawn glass part comprising a compressive stress region, a first surface and a second surface, the compressive stress region extending from the first surface of the ion-exchanged redrawn glass part to a first depth in the ion-exchanged redrawn glass part;
- and
- in a second chemical etching step, contacting the first and/or second ion-exchanged redrawn glass part surfaces with a second etchant to form a glass-based element,
- wherein the glass-based element comprises a bend strength of from about 1000 MPa to about 1800 MPa at a failure probability of 1% and an average thickness of less than 75 microns.
Dependencies are inferred from the claim text.