JP5446941B2 - Piezoelectric vibrating piece - Google Patents

Description

  The present invention relates to a piezoelectric vibrating piece.

  At present, in a piezoelectric vibrator using a thickness vibration type piezoelectric vibrating piece such as an AT-cut quartz vibrating piece, the oscillation frequency is being increased. The piezoelectric vibrating piece used in this piezoelectric vibrator has an inverted mesa structure in which the vibration region is thinly molded in order to correspond to the increase in the oscillation frequency, and a pair of thin films is formed on both main surfaces of the thinly formed vibration region. Excitation electrodes are formed (see, for example, Patent Document 1).

  In the piezoelectric vibrating piece described in Patent Document 1, a pair of excitation electrodes for excitation, a holding electrode for electrically connecting to an external terminal, and the pair of excitation electrodes are held on both main surfaces of the substrate. A sleeve electrode to be drawn out to the electrode is formed. The pair of excitation electrodes, holding electrodes, and sleeve electrodes are formed at the same time to form a thin film having the same thickness.

JP 2009-164824 A

  Since the piezoelectric vibrating reed as shown in Patent Document 1 has an inverted mesa structure, unevenness is formed on both main surfaces thereof. Therefore, the electrodes (excitation electrode, holding electrode, sleeve electrode) formed on the uneven step portion or the like may be disconnected at the edge of the step portion. In particular, in the case of a thin film electrode adapted to high frequency, the possibility of disconnection at the edge of the stepped portion becomes high.

  Another problem with the piezoelectric vibrating piece is the occurrence of spurious vibration due to another vibration mode in addition to the main vibration. This spurious vibration becomes apparent as the frequency becomes high, and the influence is easily exerted particularly in the piezoelectric vibrating piece shown in Patent Document 1 in which the thickness of the excitation region is thin.

  Accordingly, in order to solve the above-described problems, an object of the present invention is to provide a piezoelectric vibrating piece that prevents disconnection of an electrode and suppresses spurious vibration.

  In order to achieve the above object, a piezoelectric vibrating piece according to the present invention includes a substrate, a plurality of excitation electrodes that perform excitation, a holding electrode that is electrically connected to an external electrode, and the excitation electrode that is drawn out to the holding electrode. A sleeve electrode is formed; the excitation electrode is thinner than the sleeve electrode; the plurality of excitation electrodes are formed on both main surfaces of the substrate; and the plurality of excitation electrodes formed on both main surfaces of the substrate An electrode region is constituted by an electrode, and the electrode region includes a counter electrode part that the excitation electrode faces and a non-opposing electrode part that the excitation electrode does not face, and the counter electrode part is disposed around the counter electrode part. The non-opposing electrode portion is arranged continuously to the electrode portion.

  According to the present invention, it is possible to prevent the oscillation of the main vibration having the strongest vibration displacement distribution from being hindered. In addition, spurious vibrations having a vibration displacement distribution near the end of the excitation electrode (for example, (1,2,1) mode or (1,1,2) mode which is a secondary mode of thickness system, or 3 of thickness system). For the next mode (1,3,1) mode, (1,1,3) mode, etc.), the non-opposing electrode part is configured, so that the spurious vibration is suppressed by affecting the vibration displacement of each spurious. It becomes possible to do. In addition, it is possible to set the excitation electrode thin in order to cope with high frequency, and furthermore, it is possible to prevent the disconnection of the electrode by making the sleeve electrode thicker than the excitation electrode, Spurious vibration can be further suppressed. That is, according to the present invention, it is possible to simultaneously prevent electrode disconnection and suppress spurious vibration.

  The said structure WHEREIN: The said board | substrate is a crystalline material, the said excitation electrode is shape | molded by substantially square, The boundary of the said excitation electrode and the said sleeve electrode may be V shape in planar view.

  In this case, it is possible to simultaneously suppress the spurious vibrations respectively generated along the orthogonal crystal axis directions.

  The said structure WHEREIN: The thickness of the said non-opposing electrode part may be the same as the thickness of the said sleeve electrode.

  In this case, it is preferable to suppress spurious vibrations that are likely to occur accompanying the main vibration around the counter electrode portion without affecting the main vibration that mainly oscillates (excites) in the counter electrode portion.

  In the above configuration, the sleeve electrode may be thinner than the holding electrode.

  In this case, it is possible to prevent disconnection of the electrode while suppressing spurious vibration and to stabilize the bonding with the external electrode.

  In the above configuration, the sleeve electrode and the holding electrode may be formed by forming a vapor deposition film on the substrate and forming a plating film on the vapor deposition film.

  In this case, it is possible to increase the bonding strength with the external electrode while increasing the formation strength of the holding electrode on the substrate, and further, the sleeve electrode and the holding electrode are formed of a plating film. It becomes easy to increase the thickness of the electrode and the holding electrode, and it becomes possible to simultaneously prevent disconnection and suppress spurious vibration.

  According to the piezoelectric vibrating piece according to the present invention, it is possible to prevent disconnection of the electrode and suppress spurious vibration.

FIG. 1 is a schematic side view showing an internal space of a crystal resonator according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the quartz crystal resonator element according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of a crystal vibrating piece showing the configuration of an electrode according to an embodiment of the present invention. FIG. 4 shows resonance waveform data of the quartz crystal resonator element according to the embodiment of the present invention. FIG. 5 shows resonance waveform data of the quartz crystal resonator element according to the comparative example. FIG. 6 is a graph relating to the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrode of the high-frequency crystal resonator in the 100 MHz band. FIG. 7 is a graph regarding the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrode of the 300 MHz band high-frequency crystal resonator. FIG. 8 is a graph relating to the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrode of the 600 MHz band high-frequency crystal resonator. FIG. 9 is a schematic plan view of a quartz crystal resonator element according to another embodiment of the present invention. FIG. 10 is a schematic plan view of a quartz crystal resonator element according to another embodiment of the present invention. FIG. 11 is a schematic plan view of a quartz crystal resonator element according to another embodiment of the present invention.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the drawings. In the present embodiment described below, a case where the present invention is applied to a crystal resonator as a piezoelectric vibration device is shown.

-Crystal resonator 1
A crystal resonator 1 according to the present embodiment is a high-frequency crystal resonator of 100 MHz or higher, and as shown in FIG. 1, a crystal vibrating piece 2 (a piezoelectric vibrating piece referred to in the present invention) made of an AT-cut crystal, A first sealing member 3 for holding the crystal vibrating piece 2 and hermetically sealing the crystal vibrating piece 2 and a second sealing member for hermetically sealing the crystal vibrating piece 2 held by the first sealing member 3. And a sealing member 4.

  In this crystal unit 1, a package is constituted by the first sealing member 3 and the second sealing member 4, and the first sealing member 3 and the second sealing member 4 are joined by the sealing material 5. Thus, an airtightly sealed internal space 11 is formed. In the internal space 11, the quartz crystal resonator element 2 is ultrasonically bonded to the first sealing member 3 by electromechanical bonding using the conductive bumps 6 by the FCB method (Flip Chip Bonding). The conductive bump 6 is a plated bump made of a non-fluid member. Part of the holding electrodes 83 and 84 is used for the conductive bump 6. In this case, the process of forming the conductive bump 6 can be simplified, and the cost can be reduced. In this embodiment, a part of the holding electrodes 83 and 84 is used for the conductive bump 6. However, the present invention is not limited to this, and the upper part of the plating formed holding electrodes 83 and 84 described later is used. A conductive bump 6 may be formed separately. Further, although plated bumps are used as the conductive bumps 6, other conductive bumps such as metal stud bumps may be used.

  Next, each configuration of the crystal resonator 1 will be described with reference to FIGS.

-1st sealing member 3-
The 1st sealing member 3 consists of ceramics, and as shown in FIG. 1, the wall extended upward from the bottom part 31 along the main part outer periphery of the bottom part 31 and the one main surface 32 of the 1st sealing member 3 A box-like body composed of the portion 34 is formed. The first sealing member 3 is formed by laminating a ceramic rectangular parallelepiped on a single ceramic plate and integrally firing it in a concave shape.

  The top surface of the wall portion 34 of the first sealing member 3 is a bonding surface with the second sealing member 4, and the sealing material 5 used for bonding with the second sealing member 4 is used as the bonding surface. A bonding film (not shown) is formed. In the bonding film according to the present embodiment, a W or Mo metallization layer is formed on the top surface of the first sealing member 3 (the bonding surface with the second sealing member 4), and Ni or Ni is formed on the metallization layer. It consists of a thin film in which Au plating layers are laminated.

  The first sealing member 3 is formed with a cavity 35 surrounded by a bottom portion 31 and a wall portion 34, and the cavity 35 is formed in a substantially rectangular shape in plan view.

  Castellations 36 are formed at the four corners of the rear surface (other main surface 33) of the first sealing member 3. These castellations 36 are formed on the side surface of the housing and are formed along the four corners of the other main surface 33 of the first sealing member 3.

  The first sealing member 3 includes electrode pads 71 and 72 that are electromechanically bonded to the excitation electrodes 81 and 82 of the crystal vibrating piece 2 and external terminal electrodes that are electrically connected to external components and external devices. 73, 74, an electrode pad 71 and an external terminal electrode 73, and a wiring pattern 75 for electrically connecting the electrode pad 72 and the external terminal electrode 74 are formed. These electrode pads 71, 72, external terminal electrodes 73, 74, and wiring pattern 75 constitute the electrode 7 of the first sealing member 3. The electrode pads 71 and 72 are corners facing in the short side direction in a plan view of the cavity 35 of the first sealing member 3 and are formed at one end in the longitudinal direction of the first sealing member 3. The external terminal electrodes 73 and 74 are formed on the castellation 36.

  The first sealing member 3 is formed with a via 37 for conducting the excitation electrodes 81 and 82 of the crystal vibrating piece 2 from the inside of the cavity 35 to the outside of the cavity 35. Via this via 37, a wiring pattern 75 is formed from the electrode pads 71, 72 on the one main surface 32 of the first sealing member 3 to the external terminal electrodes 73, 74 on the other main surface 33. The via 37 is filled with a conductive member 76 made of Cu.

-Second sealing member 4-
The 2nd sealing member 4 consists of metal materials, and is shape | molded by the single plate of a rectangular parallelepiped planar view. The outer periphery of the lower surface of the second sealing member 4 is a bonding surface with the first sealing member, and the bonding surface includes a part of the sealing material 5 used for bonding with the first sealing member 3. A bonding film (not shown) is formed. The bonding film according to the present embodiment is made of a brazing material such as Ag low on the lower surface of the second sealing member 4 (the bonding surface with the first sealing member 3).

-Crystal vibrating piece 2-
The quartz crystal vibrating piece 2 is composed of an AT-cut quartz crystal substrate 21 that performs a thickness-shear vibration that is a crystalline material. As shown in FIGS. 2 and 3, the external shape of the quartz crystal vibrating piece 2 is a rectangular parallelepiped having a substantially rectangular shape in plan view (both main surfaces 22 and 23 are formed in a substantially rectangular shape). Further, the quartz crystal vibrating piece 2 is formed such that the long sides of both the main surfaces 22 and 23 are along the X axis and the short sides of the both main surfaces 22 and 23 are along the Z ′ axis.

  The quartz crystal resonator element 2 is provided with a vibrating portion 24 that constitutes a vibrating region, and a frame portion 25 that is electromechanically joined to the electrode pads 71 and 72 of the first sealing member 3 that is an external electrode. . The frame part 25 is provided on the outer periphery of the vibration part 24 so as to surround the vibration part 24, and the vibration part 24 and the frame part 25 are integrally formed to constitute the substrate 21. Both main surfaces 22 and 23 of the vibration part 24 are etched and thinned with respect to the frame part 25.

  The substrate 21 of the crystal vibrating piece 2 has a pair of excitation electrodes 81 and 82 for exciting, holding electrodes 83 and 84 that are electromechanically joined to the electrode pads 71 and 72 of the first sealing member 3, and a pair. Sleeve electrodes 85 and 86 are formed to lead the excitation electrodes 81 and 82 to the holding electrodes 83 and 84, and the pair of excitation electrodes 81 and 82 are drawn by the sleeve electrodes 85 and 86 to be electrically connected to the holding electrodes 83 and 84, respectively. Connected. The pair of excitation electrodes 81 and 82 is thinner than the sleeve electrodes 85 and 86, and the sleeve electrodes 85 and 86 are thinner than the holding electrodes 83 and 84. The pair of excitation electrodes 81 and 82, the holding electrodes 83 and 84, and the sleeve electrodes 85 and 86 constitute the electrode 8 of the crystal vibrating piece 2.

  As shown in FIGS. 2 and 3, the pair of excitation electrodes 81 and 82 are formed in a substantially square shape in plan view having the same shape and the same area, and the planes of the vibrating portions 24 of both the main surfaces 22 and 23 of the substrate 21. Each is formed in the visual center. Each side of the excitation electrode 81 is formed along the X axis and the Z ′ axis. The excitation electrode 82 is formed so that each side does not extend along the X axis and the Z ′ axis, and the excitation electrode 81 is planarly viewed from the center of the excitation electrodes 81 and 82 (on the main surfaces 22 and 23). In the arrangement) rotated in the range of 20 ° to 70 °. In the present embodiment, the excitation electrode 82 is arranged to be rotated by 45 ° with respect to the excitation electrode 81. As described above, when the excitation electrode 82 is rotated with respect to the excitation electrode 81, the opposing excitation electrode 81 is provided at each corner of a pair of substantially square excitation electrodes 81, 82 having the same shape in plan view. , 82 does not exist. In this way, each corner of the pair of excitation electrodes 81 and 82 is configured as a non-opposing electrode region (see the non-opposing electrode portion 88 described below), so that vibration displacement distribution is provided near the ends of the excitation electrodes 81 and 82. For example, (1,2,1) mode or (1,1,2) mode which is a second-order mode of thickness, or (1,3,1) mode which is a third-order mode of thickness or The (1, 1, 3) mode and the like are most effectively suppressed by affecting the vibration displacement.

  The pair of excitation electrodes 81 and 82 is composed of a Cr—Au film (vapor deposition film) in which Cr and Au are sequentially deposited on the substrate 21. The thickness dimension of the pair of excitation electrodes 81 and 82 is set in the range of 0.03 μm to 0.08 μm, respectively. In the present embodiment, the thickness dimension of the pair of excitation electrodes 81 and 82 is 0.05 μm. . The thickness dimensions of the excitation electrodes 81 and 82 may be different dimensions as long as they are within the range of 0.03 μm to 0.08 μm.

  The sleeve electrodes 85 and 86 are formed so as not to face both the main surfaces 22 and 23 of the vibration part 24. The sleeve electrodes 85 and 86 are constituted by a Cr—Au film in which an Au film (plating film) made of Au is further plated on the Cr—Au film (vapor deposition film) constituting the excitation electrodes 81 and 82. . The thickness dimension of the sleeve electrodes 85 and 86 is set in the range of 0.5 μm to 4.0 μm, respectively. In the present embodiment, the thickness dimension of the sleeve electrodes 85 and 86 is 1 μm. The sleeve electrodes 85 and 86 may have different thicknesses as long as they are within a range of 0.5 μm to 4.0 μm.

  The holding electrodes 83 and 84 are formed from the vibrating portion 24 to the frame portion 25. These holding electrodes 83 and 84 are made of a Cr—Au film in which an Au film (plating film) made of Au is plated on the Cr—Au film constituting the sleeve electrodes 85 and 86. The thickness dimension of the holding electrodes 83 and 84 is set in the range of 0.5 μm to 10.0 μm, respectively. In the present embodiment, the thickness dimension of the holding electrodes 83 and 84 is 2 μm. Note that the thickness dimensions of the holding electrodes 83 and 84 may be different as long as they are within the range of 0.5 μm to 10.0 μm.

  In the electrode 8 having the above configuration, the excitation electrodes 81 and 82 are formed on both main surfaces 22 and 23 of the substrate 21, and the electrode region is configured by the excitation electrodes 81 and 82 formed on both the main surfaces 22 and 23 of the substrate 21. Has been. The electrode region is composed of a counter electrode part 87 facing the excitation electrodes 81 and 82 and a non-opposing electrode part 88 not facing the excitation electrodes 81 and 82. The non-opposing electrode portion 88 referred to here is formed continuously (continuously) around the counter electrode portion 87 with the counter electrode portion 87.

  Note that the boundary 27 between the non-opposing electrode portion 88 and the sleeve electrodes 85 and 86 of the pair of excitation electrodes 81 and 82 is located in the vibrating portion 24, and as shown in FIG. ) And the Z′-axis (the short direction of the quartz crystal vibrating piece 2), or a plan view L-shape or a plan view V-shape. Further, the boundary 28 between the sleeve electrodes 85 and 86 and the holding electrodes 83 and 84 is located in the vibration part 24, and as shown in FIG. 2, the X axis (longitudinal direction of the crystal vibrating piece 2) and the Z ′ axis (crystal vibration). It becomes an L-shape in plan view formed along the short direction of the piece 2.

-Manufacture of crystal unit 1-
In the crystal unit 1 having the above-described configuration, as shown in FIGS. 1 to 3, the first sealing member 3 and the crystal vibrating piece 2 are ultrasonically electromechanically formed by the FCB method through the conductive bumps 6. Be joined. By this bonding, the excitation electrodes 81 and 82 of the crystal vibrating piece 2 are connected to the electrode pads 71 and 72 of the first sealing member 3 via the sleeve electrodes 85 and 86, the holding electrodes 83 and 84, and the conductive bumps 6. The crystal vibrating piece 2 is mounted on the first sealing member 3. And the 2nd sealing member 4 is joined to the 1st sealing member 3 in which the crystal vibrating piece 2 was mounted by welding, heat melting, etc. via the sealing material 5, and the crystal vibrating piece 2 is airtightly sealed. The manufactured quartz crystal resonator 1 is manufactured.

-Resonance waveform-
Next, the resonance waveform of the crystal resonator 1 mounted with the crystal resonator element 2 according to the present embodiment is measured, and the resonance waveform data is shown in FIG. Note that a 622 MHz band high-frequency crystal resonator was used as the crystal resonator 2 shown in FIG.

  Further, as a comparative example of the present embodiment, the configuration of the pair of excitation electrodes 81 and 82, the holding electrodes 83 and 84, and the sleeve electrodes 85 and 86 is different from the crystal vibrating piece 2 according to the present embodiment. FIG. 5 shows the resonance waveform data of a crystal resonator on which a pair of excitation electrodes 81 and 82, holding electrodes 83 and 84, and sleeve electrodes 85 and 86 are mounted.

  As shown in FIGS. 4 and 5, from the resonance waveform data, the crystal resonator 1 according to the present embodiment has a lower series resonance resistance value (CI value) of the main vibration than the crystal resonator of the comparative example, It can be seen that the spurious vibration (spurious CI) is suppressed.

-Sleeve electrodes 85, 86-
In addition, for the crystal resonator 1 on which the crystal resonator element 2 according to the present embodiment is mounted, the thickness of the sleeve electrodes 85 and 86 is varied (each 0.5 μm to 4.0 μm), and the CI of the main vibration at that time The value and the spurious CI value were measured, and the ratio of these CI values (CI ratio) was calculated. The results are shown in FIGS.

  FIG. 6 is a graph relating to the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrodes 85 and 86 of the high-frequency crystal resonator of the 100 MHz band.

  FIG. 7 is a graph relating to the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrodes 85 and 86 of the 300 MHz band high-frequency crystal unit.

  FIG. 8 is a graph relating to the CI value of the main vibration and the CI ratio with respect to the thickness of the sleeve electrodes 85 and 86 of the 600 MHz band high-frequency crystal resonator.

  As shown in FIGS. 6 to 8, it can be seen that as the thickness of the sleeve electrodes 85 and 86 increases, the CI value of the main vibration decreases and the CI ratio increases. Also, it can be seen from FIGS. 6 to 8 that the higher the oscillation frequency, the more CI value can be suppressed. Moreover, it turns out that it becomes the same characteristic even if it is any oscillation frequency from FIGS. For these reasons, it is desirable to increase the CI ratio by setting the oscillation frequency high, thickening the sleeve electrodes 85 and 86, and suppressing the CI value of the main vibration.

  However, when the sleeve electrodes 85 and 86 are thickened, other problems occur. For example, when the sleeve electrodes 85 and 86 are formed, a stress is applied to the substrate 21, and this stress is related to the thickness of the electrodes such as the sleeve electrodes 85 and 86. Specifically, when the sleeve electrodes 85 and 86 are thickened, a stress more than necessary is applied to the substrate 21, and as a result, the characteristics of the crystal unit 1 such as the aging characteristics are deteriorated. In the crystal resonator element 2 according to the present embodiment, when the thickness of the sleeve electrodes 85 and 86 exceeds 4.0 μm, the characteristics of the crystal unit 1 such as the aging characteristics start to deteriorate.

  Further, if the thicknesses of the sleeve electrodes 85 and 86 are each less than 0.5 μm, not only the CI value of the main vibration is increased and the CI ratio is decreased, but also the sleeve electrodes 85 and 86 may be disconnected.

  From the above, the thickness of the sleeve electrodes 85 and 86 is preferably set to 0.5 to 4.0 μm.

-Effects of this embodiment-
According to the present embodiment, since the vicinity of the center of the pair of excitation electrodes 81 and 82 is formed to face each other (see the counter electrode portion 87), the strongest vibration displacement distribution is provided near the center of the excitation electrodes 81 and 82. It does not disturb the oscillation of the main vibration. Further, since the corner portions of the pair of excitation electrodes 81 and 82 are not formed to face each other (see the non-opposing electrode portion 88), vibrations occur near the ends of the excitation electrodes 81 and 82 (specifically, near the corner portions). Spurious vibration having a displacement distribution (for example, (1,2,1) mode or (1,1,2) mode which is a secondary mode of thickness system, or (1,3,1) of a tertiary system of thickness system) This affects the vibration displacement of each spurious (mode, (1, 1, 3) mode, etc.) and suppresses spurious vibration. The excitation electrodes 81 and 82 on both main surfaces 22 and 23 are preferably formed at positions where their centers overlap, but the same effect can be expected even if they are slightly deviated due to manufacturing errors or the like. .

  Moreover, since the excitation electrodes 81 and 82 of both the main surfaces 22 and 23 are formed in the same shape, the excitation electrodes 81 and 82 can be formed without increasing the area of the excitation electrodes 81 and 82 formed on the crystal vibrating piece 2. It is possible to reduce the vibration area of each spurious near the corners of the excitation electrodes 81 and 82 while securing the vibration area near the center of the electrode 82. That is, spurious vibration can be suppressed without disturbing the oscillation of the main vibration while reducing the size of the crystal vibrating piece 2.

  More specifically, according to the quartz crystal resonator element 2 according to the present embodiment, the excitation electrodes 81 and 82, the holding electrodes 83 and 84, and the sleeve electrodes 85 and 86 are formed on the substrate 21, and the excitation electrodes 81 and 82 are formed on the substrate. The excitation electrodes 81, 82 are thinner than the sleeve electrodes 85, 86, and the counter electrode portion 87 is formed by the opposing electrode regions of the excitation electrodes 81, 82. Since the non-opposing electrode portion 88 is configured by the non-opposing electrode regions of the excitation electrodes 81 and 82, and the non-opposing electrode portion 88 is arranged around the counter electrode portion 87 and connected to the counter electrode portion 87, It is possible to prevent the oscillation of the main vibration having the strongest vibration displacement distribution from being disturbed. Further, spurious vibrations having a vibration displacement distribution in the vicinity of the end portions of the excitation electrodes 81 and 82 (for example, (1,2,1) mode, (1,1,2) mode which is a secondary mode of thickness system, thickness system) Since the non-opposing electrode portion 88 is configured for the (1,3,1) mode, (1,1,3) mode, etc.), the spurious vibration is affected by the vibration displacement of each spurious. Can be suppressed. Further, the excitation electrodes 81 and 82 can be set to be thin in order to cope with higher frequencies, and the sleeve electrodes 85 and 86 are made thicker than the excitation electrodes 81 and 82 to prevent the electrode 8 from being disconnected. In addition, spurious vibrations can be further suppressed. That is, according to the crystal vibrating piece 2 according to the present embodiment, it is possible to simultaneously prevent the disconnection of the electrode 8 and suppress spurious vibration.

  Further, the substrate 21 is made of a crystalline material, the excitation electrodes 81 and 82 are formed in a substantially square shape, and the boundary 27 between the excitation electrodes 81 and 82 and the sleeve electrodes 85 and 86 is V-shaped in plan view. Each spurious vibration generated along the crystal axis direction can be suppressed simultaneously.

  Further, since the sleeve electrodes 85 and 86 are thinner than the holding electrodes 83 and 84, the spurious vibration is suppressed, the disconnection of the electrode 8 is prevented, and the bonding with the external electrodes (electrode pads 71 and 72) is further stabilized. be able to.

  Further, since the sleeve electrodes 85 and 86 and the holding electrodes 83 and 84 are formed by forming a vapor deposition film on the substrate 21 and forming a plating film on the vapor deposition film, the formation of the holding electrodes 83 and 84 on the substrate 21 is formed. While increasing the strength, the bonding strength with the external electrodes (electrode pads 71, 72) can be increased, and the sleeve electrodes 85, 86 and the holding electrodes 83, 84 are formed of a plating film. It is easy to increase the thickness of the electrode 86 and the holding electrodes 83 and 84, and it is possible to simultaneously prevent disconnection and suppress spurious vibrations.

-Other embodiments-
In this embodiment, a crystal resonator is applied as the piezoelectric vibration device. However, the present invention is not limited to this, and a piezoelectric vibration device that hermetically seals the excitation electrode of a piezoelectric vibration piece that performs piezoelectric vibration. Any other device may be used, for example, a crystal oscillator.

  Moreover, in this Embodiment, although the ceramic is used for the 1st sealing member 3, and the metal material is used for the 2nd sealing member 4, the material of the 1st sealing member 3 and the 2nd sealing member 4 is used. The first sealing member 3 and the second sealing member 4 may be made of glass or the like.

  Further, in the present embodiment, the crystal resonator element 1 package in which the crystal vibrating piece 2 mounted on the first sealing member 3 is sealed by the second sealing member 4 is configured, but the present invention is not limited to this. It may be a package of a quartz crystal resonator having a sandwich structure in which a first sealing member, a crystal vibrating piece, and a second sealing member are stacked. In this sandwich structure crystal resonator, the first sealing member and the crystal vibrating piece are joined via a sealing material, and the excitation electrode formed on the other main surface of the crystal vibrating piece is connected to the first sealing member. The quartz vibrating piece is hermetically sealed, and the quartz vibrating piece and the second sealing member are bonded together via a sealing material, and the excitation electrode formed on one main surface of the quartz vibrating piece has 2 is hermetically sealed with the sealing member.

  In the present embodiment, the substrate 21 of the crystal vibrating piece 2 has the frame portion 25 thicker than the vibration portion 24. However, the present invention is not limited to this, and the thickness of the frame portion 25 is vibrated. The thickness may be the same as the thickness of the portion 24.

  In the present embodiment, the electrode pads 71 and 72 of the first sealing member 3 and the holding electrodes 83 and 84 of the crystal vibrating piece 2 are electromechanically joined, but the present invention is not limited to this. If the electrode pads 71 and 72 of the first sealing member 3 and the holding electrodes 83 and 84 of the crystal vibrating piece 2 are electrically connected, the machine of the first sealing member 3 and the crystal vibrating piece 2 is used. Other joints may be performed elsewhere.

  In the present embodiment, the boundary 28 between the sleeve electrodes 85 and 86 and the holding electrodes 83 and 84 is L-shaped in plan view, but is not limited to this, and has an arbitrary shape. Also good. In addition, although the boundary 28 between the sleeve electrodes 85 and 86 and the holding electrodes 83 and 84 is located in the vibration part 24, this is a preferred example and may be located in the frame part 25.

  Further, in the present embodiment, the outer shape of the quartz crystal vibrating piece 2 is a rectangular parallelepiped having a substantially rectangular shape in plan view, but is not limited to this. For example, as shown in FIG. The notch portion 26 may be provided in the portion 25. In another embodiment shown in FIG. 9, the notch 26 is provided in the substrate 21 by notching along the short side direction (± Z′-axis direction) from the opposing long side of the quartz crystal vibrating piece 2. ing. Therefore, it is possible to remove the adverse effect of stress distortion caused by the bonding of the conductive bump 6 to the vibrating portion 24 of the crystal vibrating piece 2.

  Further, in the present embodiment, the non-opposing electrode portion 88 of the pair of excitation electrodes 81 and 82 is thinner than the sleeve electrodes 85 and 86, but is not limited to this, and as shown in FIG. The thickness of the counter electrode portion 88 may be the same as the thickness of the sleeve electrodes 85 and 86. In this case, it is preferable to suppress spurious vibrations that are likely to occur accompanying the main vibration around the counter electrode portion 87 without affecting the main vibration that mainly oscillates (excites) in the counter electrode portion 87.

  In the present embodiment, a pair of excitation electrodes 81 and 82 having the same shape and the same area and having a substantially square shape in plan view are used. The shape of the pair of excitation electrodes 81 and 82 can be arbitrarily set as long as the non-opposing electrode portion 88 that is opposed is configured. For example, the size of the pair of excitation electrodes 81 and 82 may be different as shown in FIG. In the case of another embodiment shown in FIG. 11, a non-opposing electrode portion 88 is configured in which the entire outer periphery of the excitation electrode 81 does not face the excitation electrode 82.

  In the present embodiment, the pair of excitation electrodes 81 and 82 are formed to face both main surfaces 22 and 23 of the substrate 21, but the number of excitation electrodes is not limited to this and is arbitrary. The number may be sufficient, and a plurality of excitation electrodes may be formed so as to face each other. For example, one excitation electrode is formed on one main surface 22 of the substrate 21, two excitation electrodes are formed on the other main surface 23, one excitation electrode formed on the one main surface 22, and the other main surface 23 The two formed excitation electrodes may be formed to face each other.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is particularly suitable for a quartz crystal resonator element.

DESCRIPTION OF SYMBOLS 1 Crystal oscillator 11 Internal space 2 Crystal vibrating piece 21 Substrate 22,23 Main surface 24 Vibrating part 25 Frame part 26 Notch part 3 1st sealing member 31 Bottom part 32,33 Main surface 34 Wall part 35 Cavity 36 Caster 36 Via 4 Second sealing member 5 Sealing material 6 Conductive bump 7 Electrodes 71 and 72 of first sealing member Electrode pads 73 and 74 External terminal electrode 75 Wiring pattern 76 Conducting member 8 Electrodes 81 and 82 of crystal resonator element Excitation Electrode 83, 84 Holding electrode 85, 86 Sleeve electrode 87 Counter electrode part 88 Non-opposite electrode part

Claims (2)

In the piezoelectric vibrating piece,
A plurality of excitation electrodes that perform excitation, a holding electrode that is electrically connected to an external electrode, and a sleeve electrode that leads the excitation electrode to the holding electrode are formed on the substrate,
The excitation electrode is thinner than the sleeve electrode,
The plurality of excitation electrodes are formed on both main surfaces of the substrate, and an electrode region is configured by the plurality of excitation electrodes formed on both main surfaces of the substrate,
The electrode region is composed of a counter electrode portion where a plurality of the excitation electrodes are opposed to each other, and a non-opposing electrode portion where the plurality of the excitation electrodes are not opposed,
Around the counter electrode part, the non-opposing electrode part is arranged continuously to the counter electrode part,
The substrate is a crystalline material;
The excitation electrode is formed in a substantially square shape,
A piezoelectric vibrating piece in which a boundary between the excitation electrode and the sleeve electrode is V-shaped in plan view . The piezoelectric vibrating piece according to claim 1,
The sleeve electrode and the holding electrode are piezoelectric vibrating pieces in which a vapor deposition film is formed on the substrate and a plating film is formed on the vapor deposition film .

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