# US 8,542,070 B2 · Piezoelectric vibrator, oscillator, electronic apparatus, and radio-controlled timepiece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,070 B2 - Document ID: US8542070B2 - Status: Granted - Kind: B2 - Application number: 13/018,837 - Filed: 2011-02-01 - Published: 2011-08-04 - Granted: 2013-09-24 - Earliest claimed: 2010-02-03 - Assignees: Seiko Instruments Inc. - Applicants: Junya Fukuda - Inventors: Junya Fukuda - Web page: https://patentgrep.com/patent/US8542070B2 ## CPC - H03B 5/32: being a piezoelectric resonator (selection of piezoelectric material H10N30/00) - H03H 3/02: for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) - H03H 9/0519: {for cantilever (H03H9/1021 takes precedence)} - H03H 9/1021: {the BAW device being of the cantilever type} - H03H 9/21: Crystal tuning forks - H03H 2003/026: {the resonators or networks being of the tuning fork type} - Y10T 29/42: Piezoelectric device making - H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H) - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract There are provided a piezoelectric vibrator capable of suppressing vibration leakage while securing mounting strength of a piezoelectric vibrating reed and an oscillator, an electronic apparatus, and a radio-controlled timepiece each using the piezoelectric vibrator. The piezoelectric vibrator includes: a package that accommodates a piezoelectric vibrating reed; and a bump that mounts the base portion of the piezoelectric vibrating reed on a package. The bump includes a plurality of main bumps which is arranged in a line in the width direction of the base portion so as to be bonded to the base portion; and an auxiliary bump which is bonded to the base portion in an area between the main bumps disposed at both ends in the width direction of the base portion and an area between the main bumps and base ends of the vibrating arms in the longitudinal direction of the base portion. ## Claims ### Claim 1 A method for producing piezoelectric vibrators, comprising: (a) defining a plurality of first substrates on a first wafer and a plurality of second substrates on a second wafer; (b) forming three electrode patterns electrically isolated from one another on a respective at least some of the first substrates; (c) forming a bump in electrical contact with each of the three electrode patterns on a respective at least some of the first substrates on which the three electrode patterns are formed; (d) forming a plurality of piezoelectric vibrating reeds each having a tuning fork shape consisting of a base and a pair of arms connected to the base, three mount electrodes being formed on the base so as to be electrically isolated from one another, wherein the three mount electrodes comprise a pair of mount electrodes for receiving electricity to vibrate the arms and an auxiliary mount electrode; (e) mounting the piezoelectric vibrating reed on a respective at least some of the first substrates on which the three bumps are formed, in such a manner that the three mount electrodes are bonded, respectively, with the three bumps formed on the three electrode patterns; (f) layering the first and second wafers such that at least some of the first substrates substantially coincide respectively with at least some of the corresponding second substrates, wherein the piezoelectric vibrating reed is secured in a cavity formed between a respective at least some of the coinciding first and second substrate pairs; (g) hermetically bonding at least some of the coinciding first and second substrate pairs; (h) cutting off from the first and second wafers a respective at least some of the hermetically bonded first and second substrate pairs. ### Claim 2 (depends on 1) The method according to claim 1, wherein forming a plurality of vibrating reeds comprises forming a plurality of vibrating reeds each having a base and arms connected to the base, wherein the base is formed with a pair of notches that reduce propagation of oscillation of the arms from the arms to the pair of mount electrodes. ### Claim 3 (depends on 2) The method according to claim 2, wherein forming a plurality of vibrating reeds comprises forming the three mount electrodes on a respective at least some of the vibrating reeds, and forming the three mount electrodes comprises forming the pair of mount electrodes between a proximal end of the base and the notches and forming the auxiliary mount electrode between a distal end of the base and the notches. ### Claim 4 (depends on 3) The method according to claim 3, wherein forming the auxiliary mount electrode comprises forming the auxiliary mount electrode so as to include a nodal point therein, wherein the nodal point is located in the base at a distance from the distal end of the base equal to about a half of a width of the arms. ### Claim 5 (depends on 4) The method according to claim 4, wherein forming the auxiliary mount electrode comprises forming the auxiliary mount electrode so as to include a nodal point at a center of the auxiliary mount electrode. ### Claim 6 (depends on 3) The method according to claim 3, wherein forming the three mount electrodes comprises forming a bonding film at least in part on a respective three mount electrodes, wherein the bonding film is made of a same metal as the bump. ### Claim 7 (depends on 1) The method according to claim 1, wherein forming three electrode patterns comprises forming a second bonding film at least in part on a respective three electrode patterns. ### Claim 8 (depends on 7) The method according to claim 7, wherein the bump is made of gold. ### Claim 9 (depends on 1) The method according to claim 1, wherein mounting the piezoelectric vibrating reed comprises ultrasonically bonding the three mount electrodes respectively with the three bumps on the three electrode patterns. ### Claim 10 A piezoelectric vibrating reed comprising: a tuning fork type vibrating reed consisting of a base and a pair of vibrating arms connected to the base; and three mount electrodes formed on the base so as to be electrically isolated from one another, wherein the three mount electrodes comprise a pair of mount electrodes for receiving electricity to vibrate the arms and an auxiliary mount electrode for use in supporting the piezoelectric vibrating reed. ### Claim 11 (depends on 10) The piezoelectric vibrating reed according to claim 10, wherein the base is formed with a pair of notches that reduce propagation of oscillation of the arms from the arms to the pair of mount electrodes. ### Claim 12 (depends on 11) The piezoelectric vibrating reed according to claim 11, wherein the pair of mount electrodes are formed between a proximal end of the base and the notches, and the auxiliary mount electrode is formed between a distal end of the base and the notches. ### Claim 13 (depends on 10) The piezoelectric vibrating reed according to claim 10, wherein the auxiliary mount electrode is formed so as to include a nodal point therein, wherein the nodal point is located in the base at a distance from the distal end of the base equal to about a half of a width of the arms. ### Claim 14 (depends on 13) The piezoelectric vibrating reed according to claim 13, wherein the auxiliary mount electrode is formed so as to include a nodal point at a center of the auxiliary mount electrode. ### Claim 15 (depends on 10) The piezoelectric vibrating reed according to claim 10, wherein the three mount electrodes each comprise a bonding film formed at least in part thereon, wherein the bonding film is made of gold. ### Claim 16 (depends on 10) A piezoelectric vibrator comprising: a hermetically closed casing comprising first and second substrates with a cavity inside, wherein the first substrate is formed with three electrode patterns electrically isolated from one another on each of which a bump is formed in electrical contact with the electrode pattern; and the piezoelectric vibrating reed of claim 10 secured inside the cavity and electrically connected via the mount electrodes to the electrode patterns in such a manner that the bonding films and the bumps are fused together. ### Claim 17 (depends on 16) The piezoelectric vibrator according to claim 16, wherein the electrode patterns are each formed with a second bonding film, and bumps and the second bonding films are fused together. ### Claim 18 (depends on 16) An oscillator comprising the piezoelectric vibrator defined in claim 16. ### Claim 19 (depends on 16) An electronic device comprising the piezoelectric vibrator defined in claim 16. ### Claim 20 (depends on 19) The electronic device according to claim 19, wherein the electronic device is a radio-controlled timepiece.