Substrate polishing method and device
A substrate polishing method includes starting to rotate a circular substrate and polishing an inner peripheral edge surface of a center circular hole formed in the circular substrate into a chamfered or rounded surface by pressing the inner peripheral edge surface against a bypass polishing part of a polishing tape that is conveyed intermittently or continuously and by oscillating the bypass polishing part of the polishing tape about a direction perpendicular to a direction that the center circular hole penetrates through the circular substrate. The polishing tape is guided so as to have an advancing portion advancing toward the circular substrate, a returning portion returning from the circular substrate, and a turning-back portion between the advancing portion and the returning portion guided along a side bypass. The bypass polishing part of the polishing tape is the turning-back portion of the polishing tape.
1. A substrate polishing device comprising:
a rotary mechanism configured to hold and rotate a circular substrate formed with a circular center hole that penetrates through the circular substrate in a penetration direction; and
a polishing mechanism configured to polish at least an inner peripheral edge surface of the center circular hole formed in the circular substrate into either a chamfered surface or a rounded surface with a polishing tape, the polishing mechanism including:
a tape-conveying mechanism configured to intermittently or continuously convey the polishing tape;
a tape-polishing mechanism including (1) a roller, (2) a first groove configured to guide an advancing portion of the polishing tape toward the roller in an advancing direction, (3) a second groove configured to guide a returning portion of the polishing tape from the roller in a returning direction, (4) a first edge that causes the polishing tape to rotate from the advancing direction to a circumferential direction around the roller, and (5) a second edge that causes the polishing tape to rotate from the circumferential direction to the returning direction, the polishing tape moving in the circumferential direction being configured to polish the inner peripheral edge surface of the circular substrate;
a pressure contact mechanism configured to move the circular substrate with regard to the polishing tape to press the inner peripheral edge surface of the circular substrate against the polishing tape moving in the circumferential direction; and
a polishing-part-oscillating mechanism configured to intermittently or continuously oscillate the polishing tape in the circumferential direction.
2. The substrate polishing device according to claim 1 , further comprising a switching mechanism configured to move the rotary mechanism relative to both the tape-polishing mechanism and the polishing-part-oscillating mechanism so as to switch a position of the rotary mechanism relative to the polishing tape between (i) an inside contact position at which the inner peripheral edge surface of the circular substrate opposes the polishing tape moving in the circumferential direction and (ii) an outside contact position at which an outer peripheral edge surface of the circular substrate opposes the polishing tape moving in the circumferential direction for polishing both the inner peripheral edge surface and the outer peripheral edge surface.
3. The substrate polishing device according to claim 1 , wherein the tape-polishing mechanism further includes:
a first surface configured to guide the polishing tape from the first groove to the roller;
a second surface configured to guide the polishing tape from the roller to the second groove; and
a pressure-receiving surface configured to guide the polishing tape along the roller and to absorb pressure during polishing.
4. The substrate polishing device according to claim 3 , wherein the pressure-receiving surface part is made of a material selected from the group comprising an elastic material and a hard material.
5. The substrate polishing device according to claim 3 , wherein the polishing mechanism has either a dry polishing configuration or a wet polishing configuration.