Embodiments disclosed therein generally pertain to selectively strengthening glass. More particularly, techniques are described for selectively strengthening cover glass, which tends to be thin, for electronic devices, namely, portable electronic devices.

A glass substrate with modified surface regions is disclosed. The glass substrate includes an alkali-containing bulk, a first alkali-depleted region, a second alkali-depleted region, and a first ion-exchanged region. The alkali-containing bulk has a first surface and a second surface with the first and second surfaces on opposite sides. The first alkali-depleted region extends into the alkali-containing bulk from the first surface. The second alkali-depleted region extends into the alkali-containing bulk from the second surface. The first ion-exchanged region extends into the alkali-containing bulk from the first surface. The first alkali-depleted region, the second alkali-depleted region, and the first ion-exchanged region each have a substantially homogenous composition. A method of forming the glass substrate is disclosed. The method includes simultaneously forming the first alkali-depleted region and the first ion-exchanged region in the first surface. The method also includes near-simultaneously forming the second alkali-depleted region in the second surface.

Embodiments disclosed therein generally pertain to selectively strengthening glass. More particularly, techniques are described for selectively strengthening cover glass, which tends to be thin, for electronic devices, namely, portable electronic devices.

Glass articles having a base layer formed of glass and having a first compressive stress, an adjacent compression layer formed in the glass and having a second compressive stress, and a witness layer formed in the glass adjacent the compression layer and having a third compressive stress. The first, second and third compressive stresses all differing from one another. The witness layer also having a higher index of refraction than an index of refraction for the base or compression layers. Methods for manufacturing and methods of quality control that include the use of the witness layer are also disclosed.

Asymmetrically strengthened glass articles, methods for producing the same, and use of the articles in portable electronic device is disclosed. Using a budgeted amount of compressive stress and tensile stress, asymmetric chemical strengthening is optimized for the utility of a glass article. In some aspects, the strengthened glass article can be designed for reduced damage, or damage propagation, when dropped.

Embodiments disclosed therein generally pertain to selectively strengthening glass. More particularly, techniques are described for selectively strengthening cover glass, which tends to be thin, for electronic devices, namely, portable electronic devices.

Asymmetrically strengthened glass articles, methods for producing the same, and use of the articles in portable electronic device is disclosed. Using a budgeted amount of compressive stress and tensile stress, asymmetric chemical strengthening is optimized for the utility of a glass article. In some aspects, the strengthened glass article can be designed for reduced damage, or damage propagation, when dropped.

A glass article includes a first surface, a second surface which is opposite the first surface, a first compressive region which extends to a first compression depth in a thickness direction from the first surface, a second compressive region which extends to a second compression depth from the second surface, and a tensile region which is disposed between the first compressive region and the second compressive region. A stress profile of the first compressive region includes a first point and a first inflection point, the first inflection point is located between the first point and the first surface, a depth from the first surface to the first point is 45 to 55% of the first compression depth from the first surface, stress at the first point is greater than 50% of compressive stress of the first surface, and a thickness of the glass article is 0.01 to 0.05 mm.

A method of forming a graphene device includes: providing a glass substrate with a blocking layer disposed thereon to form a stack; providing a first electrode and a second electrode; increasing the temperature of the stack to at least 100° C.; applying an external electric field (V.sub.P) to the first electrode such that at least one metal ion of the glass substrate migrates toward the first electrode to create a depletion region in the glass substrate adjacent the second electrode; decreasing the temperature of the stack to room temperature while applying the external electric field to the first electrode; and after reaching room temperature, setting the external electric field to zero to create a frozen voltage region adjacent the second electrode.

A strengthened glass manufacturing apparatus and a strengthened glass manufacturing method are provided. The strengthened glass manufacturing apparatus includes a strengthening chamber including a first chamber having a first space, a preheating chamber including a second chamber having a second space, the second space being different from the first space, and a first induction coil in the preheating chamber.