Display window and manufacturing method thereof
According to an exemplary embodiment of the present disclosure, a method of manufacturing a display window includes preparing a mother substrate, performing a salt treatment on the mother substrate to form a silicon-rich layer in a surface of the mother substrate to a first depth from the surface of the mother substrate, and removing the silicon-rich layer, wherein the first depth is greater than a depth of any cracks in the surface of the mother substrate, and a ratio of silicon content in the silicon-rich layer to a silicon content in the mother substrate is 1.2 to 1.4.
1. A method of manufacturing a display window, comprising the steps of:
preparing a mother substrate;
performing a salt treatment on the mother substrate to form a silicon-rich layer in a surface of the mother substrate to a first depth from the surface of the mother substrate, wherein all elements of group 1 and 2 are removed from the mother substrate during the salt treatment, wherein elements of group 1 include alkali metals, and elements of group 2 include alkali earth metals; and
removing the silicon-rich layer,
wherein the first depth is greater than a depth of any cracks in the surface of the mother substrate,
and a ratio of a silicon content in the silicon-rich layer to a silicon content in the mother substrate is about 1.2 to about 1.4.
2. The manufacturing method of claim 1 , wherein
the salt treatment is performed on the mother substrate with a neutral salt that comprises potassium nitrate.
3. The manufacturing method of claim 2 , wherein
the neutral salt comprises potassium nitrate and sodium nitrate.
4. The manufacturing method of claim 3 , wherein
the neutral salt comprises about 70 wt % or more of potassium nitrate with respect to 100 wt % of the neutral salt.
5. The manufacturing method of claim 3 , wherein
an acidity of the neutral salt is from about pH 6 to about pH 8.
6. The manufacturing method of claim 1 , wherein
the salt treatment comprises dipping the mother substrate in a molten salt.
7. The manufacturing method of claim 1 , wherein
the salt treatment is performed on the mother substrate at a temperature of from about 400° C. to about 600° C.
8. The manufacturing method of claim 1 , wherein
performing a salt treatment on the mother substrate comprises performing a first salt treatment on the mother substrate at a first temperature and performing a second salt treatment on the mother substrate at a second temperature different from the first temperature.
9. The manufacturing method of claim 8 , wherein the salt treatment further comprises
performing a heat treatment between the first salt treatment and the second salt treatment.
10. The manufacturing method of claim 1 , wherein
the first depth is from about 100 nm to about 500 μm.
11. The manufacturing method of claim 1 , wherein
the silicon-rich layer includes about 72 wt % or more of silicon (Si).
12. The manufacturing method of claim 1 , wherein
removing the silicon-rich layer includes cleansing; the silicon-rich layer using a basic solution.
13. The manufacturing method of claim 12 , wherein
removing the silicon-rich layer further includes cleansing the silicon-rich layer using an acidic solution.
14. The manufacturing method of claim 1 , wherein
after removing the silicon-rich layer, a residual silicon-rich layer having a second depth remains on a surface of the window, and
wherein the second depth is equal to a difference between the first depth and the depth of the crack.