Piezoelectric wafer, piezoelectric vibration piece, and piezoelectric vibrator

Patent metadata

Field	Value
Publication number	US-10211807-B2
Application number	US-201415036734-A
Country	US
Kind code	B2
Filing date	Sep 17, 2014
Priority date	Nov 13, 2013
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

This piezoelectric wafer has: a piezoelectric vibration piece; a frame portion that supports the piezoelectric vibration piece; and a coupling portion that couples the piezoelectric vibration piece to the frame portion. The piezoelectric vibration piece is broken off at the coupling portion and separated from the piezoelectric wafer. On front and back surfaces of the coupling portion, grooved slits extending along a width direction of the coupling portion are formed except for parts of the coupling portion in the width direction. An electrode on at least one of front and back surfaces of the piezoelectric vibration piece is extracted to a frame-portion side of the piezoelectric wafer by way of the part of the coupling portion in the width direction.

First claim

The invention claimed is:

1. A piezoelectric wafer, comprising:
a piezoelectric vibration piece;
a frame portion that supports the piezoelectric vibration piece; and
a coupling portion that couples the piezoelectric vibration piece to the frame portion, wherein
the coupling portion is configured for breaking off the piezoelectric vibration piece from the frame portion at the coupling portion,
grooved slits extending along a width direction of the coupling portion are formed on front and back surfaces of the coupling portion except for a part of the coupling portion in the width direction,
an electrode on at least one of front and back surfaces of the piezoelectric vibration piece which is extracted to a frame-portion side of the piezoelectric wafer by way of the part of the coupling portion in the width direction, and
the grooved slits are formed on both sides of the part of the coupling portion in the width direction in a manner that the parts are interposed between the grooved slits.

2. The piezoelectric wafer as claimed in claim 1 , wherein
the electrode extracted to the frame-portion side of the piezoelectric wafer is a pair of electrodes for frequency adjustment, and
the pair of electrodes for frequency adjustment are formed on one of the front and back surfaces of the coupling portion.

3. The piezoelectric wafer as claimed in claim 1 , wherein
the electrode extracted to the frame-portion side is a pair of electrodes for frequency adjustment, and
one electrode and another electrode of the pair of electrodes for frequency adjustment are respectively formed on the front and back surfaces of the coupling portion.

4. The piezoelectric wafer as claimed in claim 1 , wherein
the parts in the width direction on the front and back surfaces of the coupling portion are formed at positions displaced from each other in the width direction.

5. A piezoelectric vibration piece produced by breaking off and separating the piezoelectric vibration piece from the frame portion of the piezoelectric wafer of claim 1 , the piezoelectric vibration piece further comprising, in a break-off end part broken off from the frame portion:
planar parts in which the front and back surfaces of the piezoelectric vibration piece are continuous as far as a break-off end of the break-off end part; and
bent parts in which the front and back surfaces of the piezoelectric vibration piece are bending, the planar parts and the bent parts being formed in a direction in which the piezoelectric vibration piece is broken off, wherein
the bent parts on the front and back surfaces are bending toward a front-surface side or a back-surface side of the piezoelectric vibration piece to reduce thickness, and
electrodes of the piezoelectric vibration piece are extracted to the break-off end in the planar part in which at least one of the front and back surfaces is continuous.

6. The piezoelectric vibration piece as claimed in claim 5 , wherein
the planar part in which the front surface of the piezoelectric vibration piece is continuous and the planar part in which the back surface of the piezoelectric vibration piece is continuous are formed at positions displaced from each other in a direction in which the piezoelectric vibration piece is broken off.

7. The piezoelectric vibration piece as claimed in claim 5 , wherein
the electrode extracted to the break-off end is a pair of electrodes for frequency adjustment, and
the pair of electrodes for frequency adjustment is formed in the planar part in which one of the front and back surfaces is continuous.

8. The piezoelectric vibration piece as claimed in claim 5 , wherein
the electrode extracted to the break-off end is a pair of electrodes for frequency adjustment, and
one electrode and another electrode of the pair of electrodes for frequency adjustment are formed in the planar part in which the front and back surfaces is continuous.

9. A piezoelectric vibration piece produced by breaking off and separating the piezoelectric vibration piece from the frame portion of the piezoelectric wafer of claim 1 , the piezoelectric vibration piece further comprising:
a base portion; and
a pair of vibration arm portions, the pair of vibration arm portions being juxtaposed and protruding from one end surface of the base portion, wherein
a plurality of extraction electrodes are formed on a front main surface, a back main surface, and side surfaces on both sides in each of the pair of vibration arm portions,
base portion extraction electrodes are formed on the base portion, the base portion extraction electrodes including a base portion extraction electrode for connection by which the driving electrodes are partly common-connected, and a pair of base portion extraction electrodes for external use to which the driving electrodes are partly externally extracted, and
the base portion extraction electrodes are greater in thickness than the driving electrodes formed on the front and back main surfaces of the vibration arm portions.

10. The piezoelectric vibration piece as claimed in claim 9 , wherein
edge-of-arm extraction electrodes by which the driving electrodes are partly common-connected axe formed on edge sides of the vibration arm portions,
the edge-of-arm extraction electrodes are greater in thickness than the driving electrodes, and
the base portion extraction electrodes are at least substantially equal in thickness to the edge-of-arm extraction electrodes.

11. The piezoelectric vibration piece as claimed in claim 9 , comprising a junction portion protruding from another end surface of the base portion, wherein
the junction portion comprises:
a basal end part protruding from position including a central line on the another end surface of the base portion between positions at which the pair of vibration arm portions are juxtaposed; and
an extended part extending from the basal end part toward one side in a direction in which the pair of vibration arm portions are juxtaposed, the junction portion comprising the basal end part and the extended part has an L-like shape in plan view,
a first junction extraction electrode for external use to which one of the pair of base portion extraction electrodes for external use is extracted is formed on a surface of the basal end part, and a first metal bump is formed in an upper part of the first junction extraction electrode for external use,
a second junction extraction electrode for external use to which the other one of the pair of base portion extraction electrodes for external use is extracted is formed on a surface of the extended part, and a second metal bump is formed in an upper part of the second junction extraction electrode for external use, and
the first metal bump is greater in size in plan view than the second metal bump.

12. The piezoelectric vibration piece as claimed in claim 10 , wherein
the edge-of-arm extraction electrodes have surface layers plated with a metal,
metal bumps are formed in upper parts of the base portion extraction electrodes for external use or upper parts of the junction extraction electrodes for external use, and
the metal bumps have surface layers plated with the same metal as the plating metal of the edge-of-arm extraction electrodes.

13. The piezoelectric vibration piece as claimed in claim 9 , wherein
the base portion has side parts symmetrically and equally shaped in plan view relative to a central line between positions at which the pair of vibration arm portions are juxtaposed, and
the base portion extraction electrodes are electrically insulated from each other and formed in an equal thickness on substantially the whole front and ba

Assignees

• Daishinku Corp

Inventors

• Fujii Tomo
• Shibutani Kozo
• Ishino Satoru
• Morimoto Yoshinari
• Koga Tadataka
• Otani Kazuki

Classifications

• H03H2003/026

  the resonators or networks being of the tuning fork type · CPC title

• H03H9/02393

  Post-fabrication trimming of parameters, e.g. resonance frequency, Q factor · CPC title

• H03H2003/0428

  of an electrode · CPC title

• H03H3/02

  for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) · CPC title

• H03H9/215

  consisting of quartz · CPC title