Window manufacturing method

A method for manufacturing a window, the method comprising:

• providing an initial window having a first compressive stress value;
• and
• cleaning the initial window to provide a window having a second compressive stress value,
• wherein the cleaning of the initial window comprises:
• acid cleaning the initial window by using acid;
• and
• alkali cleaning the initial window by using alkali after the acid cleaning,
• wherein a difference between the first compressive stress value and the second compressive stress value satisfies following Equations 1 and 2:
• ΔCS(MPa)=δ·t(min)+θ, [Equation 1]
• ΔCS(MPa)=α·T(° C.)+β, [Equation 2]
• wherein, in Equation 1, a following relational expression is satisfied:
• 0<γ≤10, and −300≤θ<0,
• in Equation 2, a following relational expression is satisfied:
• 0<α≤10, and 0<β≤50,
• in Equations 1 and 2, ΔCS is an absolute value of the difference between the first compressive stress value and the second compressive stress value, T is a temperature in the acid cleaning, and t is a holding time of the acid cleaning, and
• in Equations 1 and 2, words in parentheses represent following units of corresponding parameters:
• a unit of ΔCS is megapascals (MPa), and a unit of T is degrees Celsius (° C.), and a unit of t is minutes (min).