Corning Incorporated
GLASSES HAVING IMPROVED DROP PERFORMANCE

Abstract:

Chemically strengthened glass articles exhibiting superior resistance to damage when dropped onto an abrasive surface. The strengthened glass article has a stress profile in which the compressive and tensile stresses within the article vary as a function of the thickness t of the glass article. The stress profile has a first region extending from the surface of the glass article to a depth d1 into the glass, wherein d1.ltoreq.0.025t or .ltoreq.20 um and has a maximum compressive stress of at least about 280 MPa at the surface, a second region extending from a depth of at least d1 to a second depth d2 and having a local compressive stress maximum, and a third region extending from a third depth d3 in the glass to a depth of compression DOC, wherein d2.ltoreq.d3 and DOC.gtoreq.0.15t. A method of strengthening a glass article to provide resistance to damage when dropped is also provided.