Press molding method for glass and manufacturing method for glass substrate using this method

A glass substrate of which the outer periphery portion is unprocessed having the center of gravity as the center of rotation.

A glass substrate of which the outer periphery portion is unprocessed, comprising amorphous glass material or crystallized glass material having the following composition:

• 65 wt. % to 85 wt. % of SiO2, 3 wt. % to 15 wt. % of Al2O3, 0 wt. % to 12 wt. % of MgO, 0 wt. % to 10 wt. % of TiO2, 3 wt. % to 12 wt. % of Li2O, 0 wt. % to 10 wt. % of ZnO, 0 wt. % to 5 wt. % of P2O5 and 0 wt. % to 10 wt. % of ZrO2.

A glass substrate of which the outer periphery portion is unprocessed, comprising amorphous glass material or crystallized glass material having the following composition:

• 45 wt. % to 60 wt. % of SiO2, 12 wt. % to 25 wt. % of Al2O3, 12 wt. % to 25 wt. % of MgO, 0 wt. % to 12 wt. % of TiO2, 0 wt. % to 12 wt. % of Li2O, 0 wt. % to 10 wt. % of ZnO, 0 wt. % to 5 wt. % of P2O5, 0 wt. % to 10 wt. % of ZrO2, 0 wt. % to 5 wt. % of Nb2O5, 0 wt. % to 5 wt. % of Ta2O5 and 0 wt. % to 5 wt. % of Y2O3.

A glass substrate of which the outer periphery portion is unprocessed, comprising amorphous glass material having the following composition:

• 50 wt. % to 69 wt. % of SiO2, 0 wt. % to 15 wt. % of B2O3, 4 wt. % to 25 wt. % of Al2O3, 2 wt. % to 7 wt. % of Li2O, 0 wt. % to 14 wt. % of Na2O, 0 wt. % to 18 wt. % of K2O, 0 wt. % to 6 wt. % of CaO, 0 wt. % to 3 wt. % of Ta2O5, 0 wt. % to 6 wt. % of BaO, 0 wt. % to 6 wt. % of MgO, 0 wt. % to 6 wt. % of SrO, 0 wt. % to 6 wt. % of ZnO.

A manufacturing method for a glass substrate of which the outer periphery portion is unprocessed, characterized in that a first lapping process, a second lapping process, a polishing process and a washing process are carried out after a press molding process is carried out so as to compress glass between an upper mold and a lower mold without regulating the edge surface of the outer periphery portion of the glass and, then, a crystallization process or an annealing process is carried out.

A manufacturing method for a glass substrate of which the outer periphery portion is unprocessed, characterized in that a center of gravity coring process wherein a center hole is created using the center of gravity as the center of the hole is carried out and a first lapping process, a precision inner periphery edge surface process, an inner periphery edge surface polishing process, a second lapping process, a polishing process and a washing process are carried out after a press molding process is carried out so as to compress glass between an upper mold and a lower mold without regulating the edge surface of the outer periphery portion of the glass and, then, a crystallization process or an annealing process is carried out.