Methods and apparatus for improving reliability of cover substrate against impact fractures

An article, comprising:

• a substrate having inner and outer major surfaces spaced apart from one another, a plurality of edge surfaces spanning between respective peripheral edges of the inner and outer major surfaces, and a plurality of corner surfaces spanning between the respective peripheral edges of the inner and outer major surfaces and between adjacent ones of the edge surfaces;
• and
• a first elongate discontinuity having a proximal end and a distal end, the proximal end being located at, or adjacent to, a first of the plurality of edge surfaces, and the distal end being located at, or adjacent to, a second of the plurality of edge surfaces, adjacent to the first of the plurality of edge surfaces, such that the first elongate discontinuity is disposed in proximity to a first of the corner surfaces of the substrate,
• wherein the first elongate discontinuity is filled with a plastically deformable material, and the first elongate discontinuity operates to:
• (i) interrupt crack propagation resulting from a dynamic sharp impact to the outer major surface of the substrate originating between the peripheral edge and the first elongate discontinuity, (ii) direct the crack propagation toward at least one of the first and second edge surfaces, and (iii) mitigate crack propagation across the first elongate discontinuity toward a central region of the outer major surface of the substrate,
• wherein the first elongate discontinuity extends completely through a thickness of the substrate between the inner and outer major surfaces thereof, thereby separating the substrate.