Glass substrate chemical strengthening furnace apparatus

A method for chemically strengthening a glass substrate using a glass substrate chemical strengthening furnace apparatus, the glass substrate chemical strengthening furnace apparatus comprising:

• a bottom portion and a side wall extending from an edge of the bottom portion, wherein the bottom portion and the side wall define a reaction space;
• and
• a plurality of heaters which provides heat to the reaction space,
• wherein the bottom portion includes an inclined portion located at a center thereof and a collection portion disposed between the inclined portion and the side wall,
• wherein the collection portion is in a groove shape in which an upper surface thereof is further recessed than the inclined portion,
• wherein the plurality of heaters includes a bottom heater disposed in the bottom portion or adjacent to the bottom portion, and
• wherein the inclined portion includes:
• a first floor extending in a first direction;
• a second floor extending in a second direction different from the first direction;
• a first inclined portion disposed on both sides of the first floor in the second direction;
• and
• a second inclined portion disposed on both sides of the second floor in the first direction,
• wherein the first inclined portion is inclined downward to both sides of the second floor in the first direction,
• wherein the second inclined portion is inclined downward to both sides of the first floor in the second direction.