1. A piezoelectric vibrator, comprising:
a base substrate;
a lid substrate bonded to the base substrate, and that forms a cavity between the base substrate and the lid substrate;
a piezoelectric vibrating piece housed in the cavity, and that includes a crystal plate having on its outer surface excitation electrodes and mount electrodes electrically connected to the excitation electrodes, and is tapered towards ends along the longitudinal direction;
through electrodes provided in through holes formed through the base substrate;
inner electrodes formed on the base substrate to provide electrical interconnections between the piezoelectric vibrating piece and the through electrodes; and
metal bumps formed on the inner electrodes to provide electrical interconnections between the inner electrodes and the mount electrodes, and to mount the piezoelectric vibrating piece in a cantilever fashion, the metal bumps being provided in a plurality along the longitudinal direction of the piezoelectric vibrating piece, and having heights that become higher towards a position corresponding to an end of the piezoelectric vibrating piece along the longitudinal direction.
2. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrating piece is an AT-cut vibrating piece.
3. The piezoelectric vibrator according to claim 1, wherein the metal bumps are gold bumps.
4. The piezoelectric vibrator according to claim 1, wherein the crystal plate has a beveled or convex shape.
5. A method for manufacturing a piezoelectric vibrator which comprises a base substrate; a lid substrate bonded to the base substrate, and that forms a cavity between the base substrate and the lid substrate; a piezoelectric vibrating piece housed in the cavity, and that includes a crystal plate having on its outer surface excitation electrodes and mount electrodes electrically connected to the excitation electrodes, and is tapered towards ends along the longitudinal direction; through electrodes provided in through holes formed through the base substrate; inner electrodes formed on the base substrate to provide electrical interconnections between the piezoelectric vibrating piece and the through electrodes; and metal bumps formed on the inner electrodes to provide electrical interconnections between the inner electrodes and the mount electrodes, and to mount the piezoelectric vibrating piece in a cantilever fashion,
the method comprising:
forming the inner electrodes on the base substrate;
forming the metal bumps on the inner electrodes along the longitudinal direction of the piezoelectric vibrating piece such that the metal bumps have heights that become higher towards a position corresponding to an end of the piezoelectric vibrating piece along the longitudinal direction; and
bonding the mount electrodes of the piezoelectric vibrating piece to the metal bumps to mount the piezoelectric vibrating piece in a cantilever fashion.
6. An oscillator, comprising:
a piezoelectric vibrator of claim 1; and
an integrated circuit electrically connected to the piezoelectric vibrator provided as a resonator.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for testing batches of tips for pipettes, the method comprising the steps of calibrating a pipette to be tested with a recommended reference tip; fitting the pipette with a tip to be tested and performing a second calibration; and recalibrating the pipette with the reference tip.
2. The method according to claim 1, wherein a certificate is produced detailing mean volume, inaccuracy and imprecision after each of the three steps of calibration of the pipette.
3. The method according to claim 1, wherein the calibration of the pipette comprises taking more than one reading during each calibration.
4. The method according to claim 2, wherein the three certificates are compared to each other and a certificate of conformity is produced.
5. The method according to claim 4, wherein the comparison is shown in numerical andor graphical form.
6. The method according to claim 9, wherein the calibration of a variable volume pipette comprises taking 10 readings over 3 volumes during each calibration.
7. The method according to claim 3, wherein a minimum of 11 tips are used for a fixed volume pipette and 31 tips are used for variable volume pipettes.
8. The method according to claim 6, wherein a minimum of 11 tips are used for a fixed volume pipette and 31 tips are used for variable volume pipettes.
9. The method according to claim 1, wherein the calibration of the pipette comprises taking 10 readings during each calibration.