Glass article and method of manufacturing the same

Abstract

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.

What is claimed is: 
     
         1 . A method of manufacturing a glass article, the method comprising:
 forming a sheet of glass having a thickness of about 0.01 to about 0.05 millimeters (mm);   concentrating sodium ions on surfaces of the sheet of glass; and   chemically tempering the sheet of glass having the sodium ions concentrated on the surfaces of the sheet of glass.   
     
     
         2 . The method of  claim 1 , wherein the concentrating of the sodium ions on the surfaces of the sheet of glass comprises high-temperature/high-humidity treatment performed under a temperature condition of about 80 to about 90 degrees Celsius, a humidity condition of about 80 to about 90 percentages (%), and a time condition of about 4 hours or less. 
     
     
         3 . The method of  claim 1 , wherein the concentrating of the sodium ions on the surfaces of the sheet of glass comprises heat treatment performed under a temperature condition of about 600 to about 700 degrees Celsius and a time condition of about 4 hours or less. 
     
     
         4 . The method of  claim 1 , wherein the surfaces of the sheet of glass comprise a first surface and a second surface opposite the first surface, and the concentrating of the sodium ions on the surfaces of the sheet of glass comprises an electric field applying operation in which a negative voltage is applied to the first surface and a positive voltage is applied to the second surface. 
     
     
         5 . The method of  claim 4 , wherein in the electric field applying operation, an electric field is applied to the sheet of glass within a temperature controllable chamber. 
     
     
         6 . The method of  claim 5 , wherein a temperature inside the chamber in the electric field applying operation ranges from about 0 to about 400 degrees Celsius, and a magnitude of the applied electric field in the electric field applying operation ranges from about 100 volts per centimeter (V/cm) to about 2000 V/cm. 
     
     
         7 . The method of  claim 4 , wherein in the electric field applying operation, the electric field is applied to the sheet of glass in a silicon oil bath. 
     
     
         8 . A method of manufacturing a glass article, the method comprising:
 forming a sheet of glass which comprises a first surface and a second surface opposite the first surface;   performing an electric field applying operation in which a negative voltage is applied to the first surface and a positive voltage is applied to the second surface; and   chemically tempering the sheet of glass.   
     
     
         9 . The method of  claim 8 , wherein the electric field applying operation is performed using an electric field applying device, and the electric field applying device comprises a negative plate electrode which applies the negative voltage to the first surface and a positive plate electrode which applies the positive voltage to the second surface. 
     
     
         10 . The method of  claim 9 , wherein an electric field is applied to the sheet of glass within a temperature controllable chamber in the electric field applying operation, a temperature inside the chamber in the electric field applying operation ranges from about 600 to about 700 degrees Celsius, and a magnitude of the applied electric field in the electric field applying operation ranges from about 100 volts per centimeter (V/cm) to about 2000 V/cm. 
     
     
         11 . The method of  claim 9 , wherein heat supply lines are respectively connected to the negative plate electrode and the positive plate electrode to supply heat. 
     
     
         12 . The method of  claim 9 , wherein the electric field applying operation further comprises placing the sheet of glass between the negative plate electrode and the positive plate electrode, wherein each of the negative plate electrode, the positive plate electrode and the sheet of glass is provided in plural, the negative plate electrodes and the positive plate electrodes are arranged alternately, and, in the placing of the sheet of glass, the sheets of glass are respectively placed between the negative plate electrodes and the positive plate electrodes arranged alternately. 
     
     
         13 . The method of  claim 12 , wherein each of the negative plate electrodes and the positive plate electrodes of the electric field applying device is rotated to extend along a horizontal direction during the placing of the sheets of glass and extend along a vertical direction when the electric field is applied after the placing of the sheets of glass. 
     
     
         14 . The method of  claim 13 , wherein each of the negative plate electrodes and the positive plate electrodes is capable to move along the horizontal direction or the vertical direction. 
     
     
         15 . The method of  claim 9 , wherein the electric field applying operation further comprises placing the sheet of glass between the negative plate electrode and the positive electrode plate, wherein each of the negative plate electrode and the positive plate electrode is provided in singular and the sheet of glass is provided in plural, and the sheets of glass are arranged parallel to each other between the negative plate electrode and the positive plate electrode in the placing of the sheet of glass. 
     
     
         16 . The method of  claim 9 , wherein each of the negative voltage and the positive voltage comprises a direct current (DC) waveform, an alternating current (AC) waveform, a pulsed DC waveform, or a radio frequency (RF) waveform. 
     
     
         17 . A glass article comprising:
 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 of the glass article from the first surface;   a second compressive region which extends to a second compression depth in the thickness direction from the second surface; and   a tensile region which is disposed between the first compressive region and the second compressive region,   wherein a stress profile of the first compressive region is asymmetrical to a stress profile of the second compressive region, and a magnitude of compressive stress at the first surface is different from a magnitude of compressive stress at the second surface.   
     
     
         18 . The glass article of  claim 31 , wherein the magnitude of the compressive stress at the first surface is greater than the magnitude of the compressive stress at the second surface. 
     
     
         19 . The glass article of  claim 32 , wherein the first compression depth of the first compressive region is greater than the second compression depth of the second compressive region. 
     
     
         20 . A display device comprising:
 a display panel which comprises a plurality of pixels;   a cover window which is disposed on the display panel; and   an optically-clear bonding layer which is disposed between the display panel and the cover window,   wherein the cover window comprises:
 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 of the glass article from the first surface; 
 a second compressive region which extends to a second compression depth in the thickness direction from the second surface; and 
 a tensile region which is disposed between the first compressive region and the second compressive region, 
 wherein a stress profile of the first compressive region is asymmetrical to a stress profile of the second compressive region, a magnitude of compressive stress at the first surface is greater than a magnitude of compressive stress at the second surface, the second surface contacts the optically-clear bonding layer, and the first surface is located outside the second surface. 
   
     
     
         21 . The display device of  claim 20 , wherein the display device is foldable, wherein when operated in a folded state, the display device is folded such that parts of the second surface face each other and that a tensile force is applied. 
     
     
         22 . The display device of  claim 21 , wherein the first compression depth of the first compressive region is greater than the second compression depth of the second compressive region. 
     
     
         23 . An electric field applying device comprising:
 a negative plate electrode; and   a positive plate electrode which is opposite the negative plate electrode,   wherein a sheet of glass comprising a first surface and a second surface opposite the first surface is placed between the negative plate electrode and the positive plate electrode, the negative plate electrode is configured to apply a negative voltage to the first surface, and the positive plate electrode is configured to apply a positive voltage to the second surface.   
     
     
         24 . The device of  claim 23 , wherein a magnitude of an electric field applied to the sheet of glass by the negative plate electrode and the positive plate electrode ranges from about 100 volts per centimeter (V/cm) to about 2000 V/cm. 
     
     
         25 . The device of  claim 23 , further comprising heat supply lines which are connected to the negative plate electrode and the positive plate electrode, respectively, wherein the heat supply lines are configured to apply heat to the negative plate electrode and the positive plate electrode, respectively. 
     
     
         26 . The device of  claim 23 , wherein each of the negative plate electrode, the positive plate electrode and the sheet of glass is provided in plural, the negative plate electrodes and the positive plate electrodes are arranged alternately, and the sheets of glass are respectively placed between the negative plate electrodes and the positive plate electrodes arranged alternately. 
     
     
         27 . The device of  claim 26 , wherein each of the negative plate electrodes and the positive plate electrodes is rotatable. 
     
     
         28 . The device of  claim 27 , wherein each of the negative plate electrodes and the positive plate electrodes is capable to move along a horizontal direction or a vertical direction. 
     
     
         29 . The device of  claim 23 , wherein each of the negative plate electrode and the positive plate electrode is provided in singular, the sheet of glass is provided in plural, and the sheets of glass are arranged parallel to each other between the negative plate electrode and the positive plate electrode. 
     
     
         30 . The device of  claim 29 , wherein a glass protective layer is further disposed between the negative plate electrode and the positive plate electrode and is disposed between adjacent sheets of glass among the sheets of glass. 
     
     
         31 . The device of  claim 23 , wherein each of the negative voltage and the positive voltage comprises a DC waveform, an AC waveform, a pulsed DC waveform, or a periodic AC (RF) waveform. 
     
     
         32 . The device of  claim 23 , wherein a coating layer is further disposed on a surface of the negative plate electrode which faces the adjacent positive plate electrode and on a surface of the positive plate electrode which faces the adjacent negative plate electrode. 
     
     
         33 . The device of  claim 32 , wherein the coating layer comprises an electrode material. 
     
     
         34 . The device of  claim 32 , wherein the coating layer comprises an electrode protective layer, and the electrode protective layer comprises a dielectric.