US 12,371,369 B2
Glass with modified surface regions on opposing sides and methods and apparatuses for forming the same via electro-thermal poling
Timothy Evan Dimond, Corning, NY (US); Christopher William Drewnowski, Corning, NY (US); Charles Thomas McLaren, Elmira, NY (US); Mardochee Reveil, Alexandria, VA (US); Nicholas James Smith, Port Matilda, PA (US); Nicholas Ryan Wheeler, Corning, NY (US); and Thomas Michael Zajicek, Big Flats, NY (US)
Assigned to CORNING INCORPORATED, Corning, NY (US)
Filed by CORNING INCORPORATED, Corning, NY (US)
Filed on May 19, 2022, as Appl. No. 17/748,381.
Claims priority of provisional application 63/193,334, filed on May 26, 2021.
Prior Publication US 2022/0380253 A1, Dec. 1, 2022
Int. Cl. C03C 23/00 (2006.01); C03C 3/087 (2006.01)
CPC C03C 23/009 (2013.01) [C03C 3/087 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method of forming a glass substrate with modified surface regions, comprising:
providing a glass substrate having a concentration of alkali and opposing surfaces that include a first surface and a second surface;
reducing the concentration of alkali in at least one first region extending for a first thickness from the first surface via thermal poling and, near-simultaneously, reducing the concentration of alkali in at least one second region extending for a second thickness from the second surface via thermal poling,
wherein, after thermal poling, each of the at least one first region and the at least one second region has a substantially homogenous composition,
wherein thermal poling comprises contacting a first electrode to the first surface, contacting a second electrode to the second surface, and applying an alternating electrical potential difference to the glass substrate such that the first and second electrodes are alternatingly positively-biased relative to the glass substrate to induce alkali depletion in the at least one first and second regions, respectively,
wherein applying an alternating electrical potential difference to the glass substrate comprises using an alternating current (AC) waveform,
wherein using the (AC) waveform includes increasing a total voltage to the first and second electrodes as a function of time, and
wherein the AC waveform defines a duty cycle with a first half cycle in which the first electrode is positively biased and a second half-cycle in which the second electrode is positively biased, the duty cycle controlled to induce asymmetry between the first thickness and the second thickness.