GLASS SUBSTRATE POLISHING METHOD, PACKAGE MANUFACTURING METHOD, PIEZOELECTRIC VIBRATOR, OSCILLATOR, ELECTRONIC DEVICE AND RADIO TIMEPIECE
A glass substrate polishing method for polishing a glass substrate using a polishing device is provided. The glass substrate polishing method is characterized in that the polishing device includes a surface plate that is rotationally driven around a first central axis, a plate that is rotatable around a second central axis eccentric from the first central axis and presses the glass substrate toward the surface plate, and a work holder that is formed on the plate and restricts movement of the glass substrate in a surface direction while holding the glass substrate in a state in which a central axis of the glass substrate is eccentric from the second central axis. The glass substrate is polished by rotating the surface plate while the glass substrate is rotatably held in the work holder in a state in which an abrasive is interposed between the glass substrate and the surface plate.
1 . A glass substrate polishing method for polishing a glass substrate using a polishing device, the glass substrate polishing method being characterized in that
the polishing device comprises a surface plate that is rotationally driven around a first central axis, a plate that is rotatable around a second central axis eccentric from the first central axis and presses the glass substrate toward the surface plate, and a work holder that is formed on the plate and restricts movement of the glass substrate in a surface direction while holding the glass substrate in a state in which a central axis of the glass substrate is eccentric from the second central axis, and in that
the glass substrate is polished by rotating the surface plate while the glass substrate is rotatably held in the work holder in a state in which an abrasive is interposed between the glass substrate and the surface plate.
2 . The glass substrate polishing method according to claim 1 , characterized in that
one surface of the glass substrate is polished such that a recessed portion formed in another surface of the glass substrate is penetrated, and a through hole is formed in the glass substrate.
3 . The glass substrate polishing method according to claim 1 , characterized in that
a restricting member, which restricts a polishing amount of the glass substrate, is arranged on the plate in a standing condition toward the surface plate.
4 . The glass substrate polishing method according to claim 3 , characterized in that
when a finish thickness of the glass substrate is denoted by T and a maximum particle diameter of the abrasive is denoted by D, a height H of the restricting member is set to T+2D.
5 . The glass substrate polishing method according to claim 1 , characterized in that
a plurality of the work holders are formed on the plate, and a plurality of the plates are disposed along a circumferential direction of the surface plate.
6 . A package manufacturing method capable of enclosing an electronic component in a cavity formed between a plurality of substrates that are bonded to each other, the package manufacturing method being characterized by comprising:
a through hole forming step of arranging through electrodes that penetrate a first substrate among the plurality of substrates in a thickness direction and conduct a current between an inside of the cavity and an outside of the package, wherein
in the through hole forming step, through holes are formed in the first substrate made of a glass material using the glass substrate polishing method according to claim 1 .
7 . A piezoelectric vibrator characterized by being manufactured using the package manufacturing method according to claim 6 .
8 . An oscillator, characterized in that
the piezoelectric vibrator according to claim 7 is electrically connected to an integrated circuit as an oscillation element.
9 . An electronic device, characterized in that
the piezoelectric vibrator according to claim 7 is electrically connected to a time measuring portion.
10 . A radio timepiece, characterized in that
the piezoelectric vibrator according to claim 7 is electrically connected to a filter portion.