JP6119138B2 - Vibrating piece, vibrating element, vibrator, electronic device, electronic apparatus, moving body, and method of manufacturing vibrating piece - Google Patents

Description

  The present invention relates to a vibrating piece, a vibrating element, a vibrator, an electronic device, an electronic device, a moving body, and a method for manufacturing the vibrating piece.

  Quartz resonators that use quartz resonators that are excited by thickness shear vibration are suitable for miniaturization and higher frequency, and have excellent frequency-temperature characteristics. Used in. In particular, in recent years, with the reduction in size and thickness of various electronic devices such as mobile phones and computers, there has been an increasing demand for further downsizing and thickness reduction of crystal units used therefor.

  However, when trying to reduce the size of the crystal unit, the distance between the vibration region and the holding part becomes close, so that the vibration energy leaks and the CI (crystal impedance = equivalent resistance of the crystal unit) is reduced or the main vibration is reduced. In the vicinity of the resonance frequency of the thickness-shear vibration, unnecessary spurious such as a width-slip vibration depending on the contour size of the crystal vibrating piece is generated and coupled to the main vibration, the frequency and the CI are not continuous with respect to the temperature change. There was a problem that fluctuations, so-called anomalous activity dips, etc. occurred. On the other hand, in Patent Document 1, in order to avoid CI value reduction and spurious coupling, an excitation unit is provided on a rectangular AT-cut quartz substrate having a long side in the X-axis (electric axis) direction of the quartz crystal. A quartz crystal resonator element and excitation electrodes provided on the front and back main surfaces of the excitation unit, and both side surfaces (both side surfaces on the Z′-axis side) in the long side direction of the excitation unit are m-planes of crystal crystals, respectively. The crystal plane other than the m plane is formed by two planes, and the crystal plane other than the m plane is inclined at an angle of 3 ° ± 30 ′ with respect to the normal direction of the main surface of the excitation unit. An AT-cut quartz crystal resonator element is disclosed.

JP 2008-67345 A

In the quartz crystal resonator element disclosed in Patent Document 1 described above, when further miniaturization is attempted, there is a problem that a sufficient energy confinement effect cannot be obtained in the Z′-axis direction of the excitation unit, that is, the width direction of the resonator element. I found out.
Therefore, in an AT-cut quartz crystal resonator element having a long side in the X-axis direction of the crystal crystal, a small-sized resonator element that can improve the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode that is the main vibration, and A manufacturing method thereof is provided.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
[Mode 1] A method of manufacturing a resonator element according to the present mode includes an X-axis that is a crystal axis of crystal, and a Y-axis side of a Y-axis that is a crystal axis with the X-axis being a rotation axis and the Z-axis being a crystal axis Obtained by rotating the Y axis, which is the crystal axis, to the −Z axis side of the Z axis, which is the crystal axis, with the plane including the Z ′ axis obtained by rotating to the main surface and the X axis as the rotation axis Preparing a rotated Y-cut quartz substrate having a thickness in the Y′-axis direction, and etching at least one of the side surfaces intersecting the Z′-axis of the rotated Y-cut quartz substrate; Etching the rotated Y-cut quartz substrate so that a surface is formed.
According to the present embodiment, even if the vibrating piece of the rotated Y-cut quartz substrate is downsized, the thickness-shear vibration mode that is the main vibration is obtained by performing etching in which at least four crystal planes are formed on the side surface on the Z′-axis side. There is an effect that it is possible to manufacture a resonator element having an improved energy confinement effect in the Z′-axis direction.
[Mode 2] In the method for manufacturing a resonator element according to the above mode, the etching step includes a step of reducing the thickness of the rotating Y-cut quartz substrate in the Y′-axis direction by 10% or more. To do.
According to this embodiment, even if the resonator element is reduced in size, four or more crystal planes are formed on both side surfaces on the Z′-axis side by etching so that the thickness in the Y′-axis direction is reduced by 10% or more. As a result, it is possible to improve the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, and to produce a resonator element having a small CI value.
[Mode 3] In the method of manufacturing a resonator element according to the above mode, the etching step includes reducing the thickness of the rotating Y-cut quartz substrate in the Y′-axis direction within a range of 10% to less than 15%. It is characterized by including.
According to this embodiment, even if the resonator element is reduced in size, etching is performed so that the thickness in the Y′-axis direction is reduced within a range of 10% or more and less than 15%. One crystal plane is formed, and the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, is improved, and a vibration piece having a small CI value can be manufactured.
[Mode 4] In the method for manufacturing a resonator element according to the above mode, the etching step is performed by wet etching.
According to this embodiment, by performing the etching by wet etching, there is an effect that a new crystal plane generated by the wet etching can be used with the crystal anisotropy of the crystal.
[Mode 5] In the method for manufacturing a resonator element according to the above mode, in the etching step, a first mask is arranged on a main surface on the + Y′-axis side of the rotated Y-cut quartz substrate, and the −Y′-axis side is arranged. A second mask is disposed on the main surface so as to be shifted to the −Z′-axis side with respect to the first mask, and the rotated Y-cut quartz substrate is wetted through the first mask and the second mask. Etching to form an outer shape of the vibrating piece; removing the first mask and the second mask; and wet-etching the vibrating piece to form at least one of the at least four side surfaces. Forming a surface.
According to this embodiment, the resonator element including two crystal planes can be formed on the side surface on the Z′-axis side by shifting the mask for etching the outer shape of the resonator element in the Z′-axis direction. 4 can form four crystal planes on both side surfaces on the Z′-axis side, so that it is possible to manufacture a resonator element that improves the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode that is the main vibration. is there.
[Mode 6] In the method for manufacturing a resonator element according to the above mode, when the thickness of the rotated Y-cut quartz substrate is T (μm), the shift amount Δz (μm) of the second mask with respect to the first mask Satisfies the relationship of 0.75 × T × 0.8 ≦ Δz ≦ 0.75 × T × 1.2.
According to the present embodiment, the mask displacement amount Δz (μm) satisfies the relationship of the above formula, so that the vibration including the two crystal planes on the side surface on the Z′-axis side is surely obtained after the outer shape through etching of the resonator element. Since the pieces can be formed, there is an effect that in the subsequent thickness adjustment etching, it is possible to reliably manufacture a vibrating piece in which four or more crystal faces are formed on both side faces on the Z ′ axis side.
[Mode 7] In the method for manufacturing a resonator element according to the above mode, the at least four surfaces are arranged in the Y′-axis direction.
According to this embodiment, there is an effect that at least four planes can use crystal planes generated with crystal anisotropy of quartz.
[Embodiment 8] The resonator element according to this embodiment rotates the X axis that is the crystal axis of crystal and the Z axis that is the crystal axis to the −Y axis side of the Y axis that is the crystal axis with the X axis as the rotation axis. The Y ′ axis obtained by rotating the Y axis, which is the crystal axis, to the −Z axis side of the Z axis, which is the crystal axis, with the plane including the Z ′ axis obtained in this way as the main surface and the X axis as the rotation axis A rotating Y-cut quartz substrate having a thickness as a direction, and at least one of the plurality of side surfaces intersecting with the Z ′ axis of the rotating Y-cut quartz substrate includes at least four surfaces; To do.
According to this embodiment, even if the resonator element is downsized, the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode that is the main vibration is improved by having four crystal faces on the side surface on the Z′-axis side. In addition, the frequency temperature characteristic can be improved by suppressing the influence of the width-slip vibration mode.
[Mode 9] In the resonator element according to the above mode, at least one of the side surfaces includes five surfaces.
According to this embodiment, even if the resonator element is downsized, the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, is further enhanced by having five crystal planes on the side surface on the Z′-axis side. There is an effect that the frequency temperature characteristics can be improved by further suppressing the influence of the width-slip vibration mode.
[Mode 10] In the resonator element described in the above mode, the five surfaces are arranged in the Y′-axis direction.
According to this embodiment, there is an effect that the five faces can use crystal faces generated with crystal anisotropy of quartz.
[Mode 11] In the resonator element according to the above mode, the at least four surfaces are arranged in the Y′-axis direction.
According to this embodiment, there is an effect that at least four planes can use crystal planes generated with crystal anisotropy of quartz.
[Mode 12] In the resonator element according to the above mode, in the side surface having the first main surface on the + Y′-axis side, the second main surface on the −Y′-axis side, and the at least four surfaces, the end portions are mutually The angle formed by the two connected surfaces is an obtuse angle.
According to the present embodiment, in the side surface having at least four surfaces on the Z′-axis side, the angles formed by the two surfaces are all obtuse angles, so that the excitation electrode and the pad electrode are utilized using the side surface on the Z′-axis side. Are connected by the lead electrode, there is an effect that the disconnection of the lead electrode can be prevented.
[Mode 13] The resonator element according to the above mode is characterized in that a protrusion is provided on at least one main surface of the rotated Y-cut quartz substrate.
According to this embodiment, even if the resonator element is reduced in size, a mesa shape having a thick central portion and a thin peripheral portion is formed at the position where the excitation electrode is formed, so that a width-slip vibration mode or the like superimposed on the main vibration is obtained. Unnecessary waves can be suppressed, and frequency temperature characteristics can be improved.
[Embodiment 14] In the resonator element according to the above embodiment, the protrusion is arranged in a position closer to the other side surface than the side surface having the at least four surfaces in a plan view. .
According to this embodiment, even if the resonator element is downsized, the thickness bending vibration that is superimposed on the main vibration is formed by forming the mesa shape with the thick central portion and the thin peripheral portion at the position where the excitation electrode of the quartz substrate is formed. Unnecessary waves such as modes can be significantly suppressed, and the frequency temperature characteristics can be greatly improved.
[Mode 15] The vibration element according to the present mode is characterized in that an excitation electrode is disposed on the main surface of the resonator element according to the above mode.
According to this embodiment, even if the resonator element is reduced in size, there is an effect that the thickness shear vibration mode that is the main vibration can be stably excited by forming the excitation electrode.
[Mode 16] In the resonator element according to the above mode, the excitation electrode is disposed closer to the other side surface than the side surface having the at least four surfaces in a plan view. .
According to this embodiment, there is an effect that the thickness-shear vibration mode which is the main vibration can be stably excited.
[Mode 17] The vibration element according to the present mode is characterized in that an excitation electrode is disposed on the main surface of the resonator element according to the above mode at a position overlapping the projecting portion in plan view.
According to this embodiment, even if the resonator element is reduced in size, the thick central portion and the excitation electrode in the mesa shape formed by the thick central portion and the thin peripheral portion of the quartz substrate overlap in a plan view. There is an effect that an unnecessary element such as a thickness bending vibration mode to be superimposed is significantly suppressed, and a vibration element having a greatly improved frequency temperature characteristic is obtained.
[Mode 18] In the resonator element according to the above mode, the excitation electrode is arranged in a position closer to the other side surface than the side surface having the at least four surfaces in a plan view. Vibration element.
According to this embodiment, there is an effect that the thickness-shear vibration mode which is the main vibration can be stably excited.
[Mode 19] The vibration element according to the above mode, further including a pad electrode electrically connected to the excitation electrode, and the pad electrode overlaps the side surface having the at least four surfaces in a plan view. It is arranged at a position.
According to this embodiment, when the excitation electrode and the pad electrode are connected by the lead electrode using the side surface on the Z′-axis side having at least four surfaces, there is an effect that disconnection of the lead electrode can be prevented.
[Mode 20] A vibrator according to this mode includes the vibration element according to the above aspect and a package that houses the vibration element.
According to this embodiment, by accommodating a small vibration element in a package, it is possible to prevent the influence of disturbance such as temperature change and humidity change and the influence of contamination, so that frequency reproducibility, frequency temperature characteristics, CI temperature characteristics In addition, there is an effect that a small vibrator having excellent frequency aging characteristics can be obtained.
[Mode 21] An electronic device according to this mode includes the vibration element according to the above mode, an electronic component, and a container in which the vibration element and the electronic component are mounted.
According to this embodiment, by using a small vibrator excellent in frequency reproducibility, frequency temperature characteristics, CI temperature characteristics and frequency aging characteristics, and configuring an oscillation circuit, an oscillator having a small and stable oscillation characteristic can be obtained. There is an effect that the electronic device can be miniaturized.
[Mode 22] An electronic apparatus according to this mode includes the vibration element according to the above mode.
According to this embodiment, there is an effect that a small electronic device having a good reference frequency source can be configured by using a small vibration element having a small CI value and good frequency temperature characteristics.
[Mode 23] A moving body according to this mode includes the vibration element according to the above mode.
According to the present embodiment, a small electronic device having a stable reference frequency source can be configured by using a small vibration element having a small CI value and good frequency temperature characteristics. There is an effect that can be.

  [Application Example 1] A method of manufacturing a resonator element according to this application example includes an X-axis that is a crystal axis of crystal, and a Y-axis that is a Y-axis that is a crystal axis with the X-axis being a rotation axis and the Z-axis being a crystal axis. A surface including the Z ′ axis obtained by rotating toward the axis side is a principal surface, and the Y axis that is the crystal axis is rotated toward the −Z axis side of the Z axis that is the crystal axis with the X axis as the rotation axis. A step of preparing a rotating Y-cut quartz substrate composed of a quartz plate having a thickness in the Y′-axis direction, and at least four surfaces formed on at least one side surface intersecting with the Z′-axis. And etching the side surface.

  According to this application example, even if the vibrating piece of the rotating Y-cut quartz substrate is reduced in size, the thickness shear vibration that is the main vibration is obtained by performing etching that forms at least four crystal planes on the side surface on the Z′-axis side. There is an effect that it is possible to manufacture a resonator element having an improved energy confinement effect in the Z′-axis direction of the mode.

  Application Example 2 In the method for manufacturing a resonator element according to the application example described above, the etching step is performed by setting the thickness in the Y′-axis direction to the thickness in the Y′-axis direction of the rotating Y-cut quartz substrate. It is characterized by being made thinner by 10% or more.

  According to this application example, even if the resonator element is reduced in size, four or more crystal planes are formed on both side surfaces on the Z′-axis side by etching so that the thickness in the Y′-axis direction is reduced by 10% or more. As a result, it is possible to improve the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, and to produce a resonator element having a small CI value.

  Application Example 3 In the method for manufacturing a resonator element according to the application example described above, the etching step is performed by setting the thickness in the Y′-axis direction to the thickness in the Y′-axis direction of the rotating Y-cut quartz substrate. It is characterized by thinning in the range of 10% or more and less than 15%.

  According to this application example, even if the resonator element is reduced in size, etching is performed so that the thickness in the Y′-axis direction is reduced within a range of 10% or more and less than 15%. One crystal plane is formed, and the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, is improved, and a vibration piece having a small CI value can be manufactured.

  Application Example 4 In the method for manufacturing a resonator element according to the application example, the etching is wet etching.

  According to this application example, by performing the etching by wet etching, there is an effect that a new crystal plane generated by the wet etching can be used with the crystal anisotropy of the crystal.

  Application Example 5 In the method for manufacturing a resonator element according to the application example described above, in the etching step, a first mask is disposed on a main surface on the + Y′-axis side of the rotated Y-cut quartz substrate, and a −Y′-axis is formed. A second mask is arranged on the main surface on the side so as to be shifted to the −Z′-axis side with respect to the first mask, and the rotated Y-cut quartz crystal substrate through the first mask and the second mask Forming the outer shape of the vibrating piece by wet etching, removing the first mask and the second mask, and wet etching the vibrating piece from which the mask has been removed, Forming at least four surfaces.

  According to this application example, the resonator element including two crystal planes can be formed on the side surface on the Z′-axis side by shifting the mask for external penetration etching of the resonator element in the Z′-axis direction, and the thickness adjustment thereafter. In etching, since four crystal planes can be formed on both side surfaces on the Z′-axis side, it is possible to manufacture a resonator element that improves the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode that is the main vibration. There is.

  Application Example 6 In the method for manufacturing a resonator element according to the application example described above, when the thickness of the rotated Y-cut quartz substrate is T (μm), a shift amount Δz (μm) of the second mask with respect to the first mask. ) Is set within a range of 0.75 × T × 0.8 ≦ Δz ≦ 0.75 × T × 1.2.

  According to this application example, by setting the mask shift amount Δz (μm) within the above range, the resonator element reliably includes two crystal planes on the side surface on the Z′-axis side after the outer shape through etching of the resonator element. Therefore, in the subsequent thickness adjustment etching, there is an effect that a resonator element in which four or more crystal planes are reliably formed on both side surfaces on the Z′-axis side can be manufactured.

  Application Example 7 In the resonator element according to this application example, the X axis that is the crystal axis of the crystal and the Z axis that is the crystal axis with the X axis as the rotation axis are moved to the −Y axis side of the Y axis that is the crystal axis. Y obtained by rotating the Y axis, which is the crystal axis, to the −Z axis side of the Z axis, which is the crystal axis, with the plane including the Z ′ axis obtained by rotation as the principal plane and the X axis as the rotation axis 'At least one side surface intersecting with the Z' axis of the rotating Y-cut quartz crystal substrate composed of a quartz plate having a thickness in the axial direction includes at least four surfaces.

  According to this application example, the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, is improved by having four crystal planes on the side surface on the Z′-axis side even if the vibration piece is downsized. In addition, the frequency temperature characteristic can be improved by suppressing the influence of the width-slip vibration mode.

  Application Example 8 In the resonator element according to the application example described above, the one side surface includes five surfaces.

  According to this application example, the energy confinement effect in the Z′-axis direction of the thickness-shear vibration mode, which is the main vibration, is further improved by having five crystal planes on the side surface on the Z′-axis side even if the resonator element is downsized. There is an effect that the frequency temperature characteristic can be further improved by further suppressing the influence of the width-slip vibration mode.

  Application Example 9 In the resonator element according to the application example described above, in the first main surface on the + Y′-axis side, the second main surface on the −Y′-axis side, and the four surfaces or the five surfaces, end portions The angle between two surfaces connected to each other is an obtuse angle.

  According to this application example, in the four or five crystal planes on the side surface on the Z′-axis side, the angles formed by the two surfaces are all obtuse angles, so that the excitation electrode can be used using the side surface on the Z′-axis side. When the lead electrode is connected to the pad electrode, the lead electrode can be prevented from being disconnected.

  Application Example 10 In the resonator element according to the application example described above, a protrusion is provided on at least one main surface of the rotated Y-cut quartz crystal substrate.

  According to this application example, even if the resonator element is downsized, a width-shear vibration mode or the like that is superimposed on the main vibration is obtained by having a mesa shape including a thick central portion and a thin peripheral portion at a position where the excitation electrode is formed. This is effective in suppressing unnecessary waves and improving the frequency temperature characteristics.

  Application Example 11 The vibration element according to this application example includes excitation electrodes on the front and back main surfaces of the resonator element according to the application example.

  According to this application example, even if the vibration piece is reduced in size, by forming the excitation electrode, it is possible to stably excite the thickness-shear vibration mode that is the main vibration.

  Application Example 12 A vibrator according to this application example includes the vibration element according to the application example described above and a package that houses the vibration element.

  According to this application example, since the small vibration element is accommodated in the package, it is possible to prevent the influence of disturbance such as temperature change and humidity change and the influence of contamination, so that frequency reproducibility, frequency temperature characteristics, CI temperature There is an effect that a small vibrator having excellent characteristics and frequency aging characteristics can be obtained.

  Application Example 13 An electronic device according to this application example includes the vibration element according to the application example, an electronic component, and a container on which the vibration element and the electronic component are mounted. .

  According to this application example, a small oscillator having excellent frequency reproducibility, frequency temperature characteristics, CI temperature characteristics, and frequency aging characteristics is used, and an oscillator having a small and stable oscillation characteristic is configured by configuring an oscillation circuit. The electronic device can be downsized.

  Application Example 14 An electronic apparatus according to this application example includes the vibration element described in the application example.

  According to this application example, by using a small vibration element having a small CI value and good frequency temperature characteristics, there is an effect that a small electronic device including a good reference frequency source can be configured.

  Application Example 15 A moving body according to this application example includes the vibration element described in the application example.

  According to this application example, a small electronic device having a stable reference frequency source can be configured by using a small vibration element having a small CI value and good frequency temperature characteristics. There is an effect that can be done.

It is the schematic which showed the structure of the vibration piece which concerns on one Embodiment of this invention, (a) is a top view, (b) is PP sectional drawing. The figure for demonstrating the relationship between an AT cut quartz substrate and a crystal axis. FIG. 3 is a schematic cross-sectional view of the crystal substrate and the resonator element in a process illustrating an example of a method for manufacturing the resonator element according to the embodiment of the invention. It is a figure explaining the vibration displacement with respect to Z'-axis edge part cross-sectional shape of the vibration element which concerns on one Embodiment of this invention, (a) is Z'-axis edge part cross-sectional shape with less than 10% of etching amounts, (b) is The cross-sectional shape of the Z′-axis end portion with an etching amount of 10% or more and less than 15%, (c) is the cross-sectional shape of the Z′-axis end portion with an etching amount of 15% or more, and (d) is a vibration displacement diagram for each etching amount. It is a graph which shows the temperature characteristic of the CI value of the vibration element which is 1.390 (mm) in the X-axis direction and 0.970 (mm) in the Z′-axis direction of the resonator element. (B) shows the characteristics of the resonator element having the resonator element according to the invention. It is a graph which shows the temperature characteristic of CI value of a vibration element whose dimension of the X-axis direction of a vibration piece is 1.390 (mm), and is 0.975 (mm) of the Z'-axis direction. (B) shows the characteristics of the resonator element having the resonator element according to the invention. It is a figure explaining the vibration displacement with respect to the X-axis end part cross-sectional shape of the vibration element which concerns on one Embodiment of this invention, (a) is X-axis end part cross-sectional shape of less than 10% of etching amounts, (b) is the etching amount. The X-axis end cross-sectional shape of 10% or more and less than 15%, (c) is the X-axis end cross-sectional shape of the etching amount of 15% or more, and (d) is the thickness bending vibration energy distribution diagram for each etching amount. 4A and 4B are schematic views showing another structure of the resonator element according to the embodiment of the invention, in which FIG. 4A is a plan view, and FIG. FIG. 5 is a schematic cross-sectional view of a quartz substrate and a vibrating piece in a step (outer shape processing step) showing an example of another method for manufacturing the vibrating piece according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a quartz crystal substrate and a vibrating piece in a step (mesa processing step) showing an example of another method for manufacturing the vibrating piece according to an embodiment of the present invention. It is the schematic which showed the structure of the vibration element which concerns on one Embodiment of this invention, (a) is a top view, (b) is PP sectional drawing. It is the schematic which showed the structure of the vibrator | oscillator which concerns on one Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view. FIG. 8 is a longitudinal sectional view showing a modification of the vibrator according to the embodiment of the present invention, where (a) is a longitudinal sectional view of Modification 1 and (b) is a longitudinal sectional view of Modification 2. It is the schematic which showed the structure of the electronic device which concerns on one Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view. The perspective view which shows the structure of the mobile type (or notebook type) personal computer to which the electronic device provided with the vibration element which concerns on one Embodiment of this invention is applied. The perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device provided with the vibration element which concerns on one Embodiment of this invention is applied. The perspective view which shows the structure of the digital still camera to which the electronic device provided with the vibration element which concerns on one Embodiment of this invention is applied. The perspective view which shows the structure of the motor vehicle which applied the vibrator and electronic device provided with the vibration element which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic views showing the structure of a resonator element according to an embodiment of the present invention, in which FIG. 1A is a plan view of the resonator element, and FIG. 1B is a PP of FIG. 1A. It is sectional drawing.

(Structure of vibrating piece)
The resonator element 1 has a vibrating portion 12 at the center of the quartz substrate 10, and the crystal axis of the quartz substrate 10 is a crystal axis with the X axis (electrical axis) direction as a long side and the X axis as a rotation axis. It is a rectangle whose short side is the Z′-axis direction obtained by rotating a certain Z-axis (optical axis) in the −Y-axis direction of the Y-axis (mechanical axis) that is the crystal axis. Further, both side surfaces 22 in the direction along the X axis intersecting the Z ′ axis of the resonator element 1 are the first crystal surface 24, the second crystal surface 25, the fourth crystal surface 27, and the fifth crystal surface 28. It consists of four sides.

  As shown in FIG. 2, the quartz substrate 10 has crystal axes X, Y, and Z orthogonal to each other. The X axis is called an electric axis, the Y axis is a mechanical axis, and the Z axis is called an optical axis. A flat plate cut out along a plane obtained by rotating the surface about the X axis by a predetermined angle θ, which is a so-called rotated Y-cut quartz substrate.

  When the angle θ of the rotated Y-cut quartz substrate is 35.25 ° (35 ° 15 ′), it is called an AT-cut quartz substrate and has excellent temperature characteristics. Here, the AT-cut quartz substrate has crystal axes X, Y ′, and Z ′ that are orthogonal to each other, the thickness direction is the Y ′ axis, and the surface that includes the X and Z ′ axes orthogonal to the Y ′ axis is the main surface. A thickness-shear vibration is excited as a main vibration on the main surface.

(Manufacturing method of vibrating piece)
Next, a method for manufacturing a resonator element according to an embodiment of the present invention will be described with reference to schematic cross-sectional views of the quartz substrate and the resonator element in the manufacturing process of FIG. In consideration of mass productivity and manufacturing cost, the resonator element 1 is generally manufactured from a large substrate by a batch processing method. Here, a schematic cross-sectional view of one vibrating piece 1 will be described. The quartz substrate 10 will be described with an example using an AT cut quartz substrate.
The resonator element 1 is trimmed so that the X-axis direction is the long side, the Z′-axis direction is the short side, and the Y′-axis direction is the thickness. First, the quartz substrate 10 is lapped or polished to prepare the quartz substrate 10 having a desired plane and thickness. For example, chromium (Cr) 31 serving as an underlayer having a predetermined thickness and gold (Au) 32 serving as a corrosion-resistant layer are sputtered or deposited on both the front and back main surfaces of the quartz substrate 10 and a resist 33 is applied. Masks 30a and 30b are formed using a wet etching technique (FIG. 3A). At this time, the mask 30a on the + side in the Y′-axis direction of the quartz substrate 10 is placed on the − side in the Y′-axis direction so that both side surfaces 20 in the Z′-axis direction have a side surface shape constituted by two crystal faces. The mask 30b is shifted by a certain amount Δz (μm) in the Z′-axis direction of the quartz crystal.

The mask displacement amount Δz (μm) is Δz = 0.75 × T ± 20%, that is, 0.75 × T × 0.8 ≦ Δz ≦ when the thickness of the quartz substrate 10 is T (μm). What is necessary is just to set in the range of 0.75xTx1.2. The ratio between the first crystal face 24 and the second crystal face 25 constituting the side surface 20 has a certain width in the mask shift amount Δz, so that the value is 0.75 × T × 0.8. It can be changed by selecting within the range of ≦ Δz ≦ 0.75 × T × 1.2.
In this case, the mask shift amount Δz (μm) is in the range of 0.75 × T × 0.8 ≦ Δz ≦ 0.75 × T × 1.2, where the thickness of the AT-cut quartz plate is T (μm). If the value is set within the range, there is no possibility of shifting the mask excessively or the amount of shifting of the mask becomes insufficient, and the side surface 20 along the X-axis direction can be processed efficiently and reliably in a shorter etching time.
Here, shifting the mask in the Z′-axis direction means that the mask is overlapped on both principal surfaces of the quartz substrate 10 and overlaps the other mask at the end on the side where the m-plane appears by wet etching. In other words, it is arranged so as not to overlap the other mask at the end on the side where the crystal plane appears.

  Next, the quartz substrate 10 exposed from the mask opening is wet etched using an ammonium fluoride solution or the like. Due to the etching anisotropy of quartz, first to third crystal planes 24 to 26 of quartz inclined at different angles from the main surface of the quartz substrate 10 appear on the exposed surface of the quartz substrate 10 (FIG. 3B). )). In FIG. 3B, on the + side in the Y′-axis direction of the quartz substrate 10 are the second crystal plane 25 and the r-plane which are m-planes of natural surfaces peculiar to quartz on the − side in the Z′-axis direction. The third crystal plane 26 is formed so as to be in contact with each other, and a first crystal plane 24 that is a natural plane of quartz other than the m plane is formed on the + side in the Z′-axis direction. On the negative side in the Y′-axis direction of the quartz substrate 10, the second crystal plane 25 that is the m-plane of the quartz crystal and the third plane that is the r-plane are on the positive side in the Z′-axis direction. The crystal plane 26 is formed so as to be in contact with each other, and the first crystal plane 24 which is a natural plane of the other crystal is formed on the − side in the Z′-axis direction. Thereafter, when the etching of the exposed surface of the quartz substrate 10 is further advanced, the unmasked quartz portion completely penetrates, and both side faces 20 in the Z′-axis direction are formed by the first crystal face 24 and the second crystal face 25. The side surface shape is composed of two crystal planes consisting of (FIG. 3C).

Subsequently, the resist 33 is peeled off, and all of chromium (Cr) 31 and gold (Au) 32 are removed (FIG. 3D). Thereafter, the entire periphery of the vibrating piece 101 having two crystal faces on both side surfaces 20 in the Z′-axis direction is etched using an ammonium fluoride solution or the like, and the thickness of the vibrating portion 12 is adjusted so as to obtain a desired frequency. adjust.
The etching amount Md is represented by the following formula (1) based on the thickness of the vibration part 12 of the quartz substrate 10.
Md = (T0−Tx) / T0 (%) (1)
Here, T0 is the thickness of the vibrating portion 12 of the quartz substrate 10 before thickness adjustment etching, and Tx (where x is 1 to 3) is the thickness of the vibrating portion 12 of the quartz substrate 10 after thickness adjustment etching.
That is, Md is the difference between the thickness of the vibrating portion 12 of the quartz substrate 10 before thickness adjustment etching and the thickness of the vibrating portion 12 of the quartz substrate 10 after thickness adjustment etching. It represents with the ratio (%) with respect to the thickness of the vibration part 12 of the quartz substrate 10.
When the amount of thickness Md to be removed by wet etching (hereinafter referred to as the etching amount Md) is less than 10%, both side surfaces 21 in the Z′-axis direction of the resonator element 102 are two surfaces having a shape before thickness adjustment etching. Although composed of crystal planes, the region of the first crystal plane 24 tends to be large and the region of the second crystal plane 25 tends to be small (FIG. 3 (e)).
Next, when the etching amount Md is 10% or more and less than 15%, as a result of experiment and analysis, both side surfaces 22 in the Z′-axis direction of the resonator element 103 are the first crystal plane 24 and the second crystal plane 25. Then, it was found that the side surface shape was composed of four crystal planes including the newly generated fourth crystal plane 27 and the fifth crystal plane 28 (FIG. 3 (f)).

First, on the side surface on the −Z ′ side, new fourth crystal surface 27 and fifth crystal surface 28 formed between the −Y ′ side main surface of the quartz substrate 10 and the first crystal surface 24 are formed. The side surface shape is composed of four crystal planes.
The angle formed between the −Y′-side main surface of the quartz substrate 10 and the fourth crystal surface 27, the angle formed between the fourth crystal surface 27 and the fifth crystal surface 28, and the fifth crystal surface 28 and the first crystal surface 27. The angle formed by the crystal plane 24, the angle formed by the first crystal plane 24 and the second crystal plane 25, and the angle formed by the second crystal plane 25 and the + Y ′ side main surface are all obtuse angles. .
Then, the side surface on the + Z ′ side includes the new fourth crystal surface 27 and the fifth crystal surface 28 formed between the + Y ′ side main surface of the quartz substrate 10 and the first crystal surface 24 4. It becomes a side surface shape constituted by the crystal plane of the surface.
The angle formed between the + Y′-side main surface of the quartz substrate 10 and the fourth crystal surface 27, the angle formed between the fourth crystal surface 27 and the fifth crystal surface 28, the fifth crystal surface 28 and the first crystal The angle formed by the surface 24, the angle formed by the first crystal surface 24 and the second crystal surface 25, and the angle formed by the second crystal surface 25 and the −Y ′ side main surface are all obtuse angles. .
When the etching is further performed and the etching amount Md is set to 15% or more, the both side surfaces 23 in the Z′-axis direction of the resonator element 104 are newly formed between the first crystal surface 24 and the fifth crystal surface 28. It was found that 6 crystal planes 29 were formed and the side surface shape was composed of 5 crystal planes (FIG. 3G).
On both side surfaces 23 in the Z′-axis direction, an angle formed between the main surface of the quartz substrate 10 and the fourth crystal surface 27, an angle formed between the fourth crystal surface 27 and the fifth crystal surface 28, and a fifth crystal An angle formed by the plane 28 and the sixth crystal plane 29, an angle formed by the sixth crystal plane 29 and the first crystal plane 24, an angle formed by the first crystal plane 24 and the second crystal plane 25, The angles formed by the second crystal plane 25 and the main surface of the quartz crystal substrate 10 are all obtuse angles.

Therefore, after forming the outer shape of the resonator element, it has been found that a new crystal plane is formed on the side surface in the Z′-axis direction by performing further wet etching such as thickness adjustment, so that the etching amount Md is 10%. With the above configuration, it is possible to manufacture a resonator element having side surfaces in the Z′-axis direction that are configured by four to five crystal planes.
The tilt angle of each crystal plane with respect to the normal direction of the main surface of the quartz substrate 10 is about 3 ° (3 ° ± 2 °, that is, in the range of 1 ° to 3 °) for the first crystal plane 24, and the second angle. The crystal plane 25 is about 54 ° (54 ° ± 2 °, ie, in the range of 52 ° to 56 °), and the third crystal plane 26 is about 68 ° (68 ° ± 2 °, ie, in the range of 66 ° to 70 °). ), The fourth crystal plane 27 is about 37 ° (37 ° ± 2 °, ie, in the range of 35 ° -39 °), and the fifth crystal plane 28 is about 18 ° (18 ° ± 2 °, ie, 16 ° ˜ The range of 20 °), the sixth crystal plane 29 is about 10 ° (10 ° ± 2 °, ie in the range of 8 ° to 12 °).
The simulation and experiment of the present inventors that the effect of improving the energy confinement effect of the thickness-shear vibration mode, which is the main vibration, cannot be obtained when the inclination angle of each crystal plane is out of the above-mentioned inclination angle range. It is confirmed from the verification by. Furthermore, it has been found that by setting the tilt angle of each crystal plane within the above tilt angle range, the influence of the unnecessary mode can be further suppressed and the temperature characteristic of the CI value can be improved. did.

  4A, 4B, and 4C show the cross-sectional shapes of the Z′-axis end portions of the vibrating pieces 102, 103, and 104 with respect to the etching amount Md, and FIG. 4D shows the excitation electrode. 15 shows the vibration displacement in the Z′-axis direction of the resonator elements 102, 103, 104 having the shape 15. As shown in FIG. 4D, the vibration displacement of the main vibration at the end in the Z′-axis direction tends to attenuate as the etching amount Md increases on both side surfaces in the Z′-axis direction of the resonator element. Yes. That is, it is considered that the vibration displacement of the main vibration at the end portion in the Z′-axis direction is further attenuated by forming the side surface shape in which both side surfaces in the Z′-axis direction of the vibrating piece are constituted by a plurality of crystal planes. . The inventors of the present application succeeded in further improving the energy confinement effect by increasing the etching amount Md and configuring the side surface in the Z′-axis direction with many crystal planes. Furthermore, it has also been found that the unnecessary mode can be suppressed and is effective in reducing the CI value.

FIGS. 5 and 6 are graphs showing the temperature characteristics of the CI value. FIGS. 5A and 6A show that the side surface in the Z′-axis direction of the resonator element as in the prior art is composed of two crystal planes. FIG. 5B and FIG. 6B show the CI characteristics when the side surface in the Z′-axis direction of the resonator element according to the present invention is composed of four crystal planes. It is a graph which shows the temperature characteristic of a value.
When the resonance frequency of the vibrating piece is 27 MHz, the CI when the size of the crystal piece in the X-axis direction is constant at 1.390 (mm) and the size of the crystal piece in the Z′-axis direction is 0.970 (mm). 5 is a graph showing the temperature characteristics of the values, and FIG. 6 is a graph showing the temperature characteristics of the CI values when the dimension of the crystal piece in the Z′-axis direction is 0.975 (mm). It can be observed that the resonator element according to the present invention can reduce the CI value as compared with the conventional structure. Furthermore, it has also been confirmed that the present invention can reduce the CI value regardless of the dimension of the crystal piece in the Z′-axis direction.
In addition, it seems that it is possible to increase the energy confinement effect in the Z′-axis direction by forming a new crystal plane on the side surface in the Z′-axis direction by applying an etching amount Md of 30% or more. Since CI value deterioration due to unevenness caused by etch pits (also called etch channels) is expected on the surface of the surface, the upper limit of the etching amount Md is considered to be about 30%.

By the way, when adjusting the thickness of the resonator element by wet etching, the following phenomenon also occurs on the side surface intersecting the X axis.
FIGS. 7A, 7B, and 7C show cross-sectional shapes in the X-axis direction of the resonator elements 102, 103, and 104 with respect to the etching amount Md. FIG. The amplitude energy of the thickness bending vibration in the X-axis direction of the resonator elements 102, 103, and 104 having the shape of FIG.
When the etching amount Md is 10% or more, the + side surfaces 131b and 131c in the X-axis direction of the resonator elements 103 and 104 have a new inclination angle with respect to the normal direction of the main surface of the quartz substrate 10. A crystal plane is formed, and a side surface shape composed of four or more crystal planes is formed. In proportion to the increase in the etching amount Md, the number of crystal planes constituting the + side surface in the X-axis direction increases. It became clear.
That is, when the etching amount Md is 10% or more and less than 15%, the − side surface 121b in the X-axis direction of the resonator element 103 has an inclination angle of about 25 ° (25 ° ± 2 °, that is, 23 ° to 27 °). Of the crystal planes 125 and 126 in the range of (2)), and the same shape as when the etching amount Md is less than 10%. However, the side surface 131b on the + side in the X-axis direction includes crystal surfaces 133 and 134 having an inclination angle of about 27 ° (27 ° ± 2 °, that is, a range of 25 ° to 29 °), and a new + Y ′ of the quartz substrate 10. The crystal surface 135 having an inclination angle of about 58 ° (58 ° ± 2 °, that is, a range of 56 ° to 60 °) generated between the side main surface and the crystal surface 133, and the −Y ′ side main surface of the crystal substrate 10. And a crystal plane 136 having a tilt angle of about 58 ° (58 ° ± 2 °, in other words, a range of 56 ° to 60 °) generated between the crystal plane 134 and the crystal plane 134. (FIG. 7B).

When the etching is further performed and the etching amount Md is set to 15% or more, the − side surface 121c in the X-axis direction of the vibrating piece 104 has an inclination angle of about 25 ° (25 ° ± 2 °, that is, 23 ° to 27 °). The side surface shape is composed of two crystal planes of the crystal planes 125 and 126 in the range (°), and is the same shape as when the etching amount Md is less than 15%. However, the side surface 131c on the + side in the X-axis direction has crystal planes 133 and 134 with an inclination angle of about 27 ° and a crystal plane 135 with an inclination angle of about 58 ° (32 ° ± 2 °, that is, a range of 30 ° to 34 °). , And an inclination angle of about 86 ° (86 ° ± 2 °, that is, 84 ° to 88 °) newly generated between the + Y ′ side main surface of the quartz crystal substrate 10 and the crystal surface 135. ) Of the crystal plane 137 and the tilt angle generated between the −Y ′ side main surface of the quartz crystal substrate 10 and the crystal plane 136 is about 86 ° (86 ° ± 2 °, that is, a range of 84 ° to 88 °). And the crystal plane 138, and a side surface shape composed of six crystal planes (FIG. 7C).
By forming a plurality of surfaces on the X-axis end surface as described above, the amplitude energy of the thickness bending vibration can be suppressed as shown in FIG. 7D, and the CI value can be improved.
In other words, the vibration piece is located at the end along the Z ′ of the vibration piece at a position where the energy of bending vibration is attenuated such as X1, X2, and X3 in FIG. Although the size of the vibrating piece in the X-axis direction is determined so that the position becomes the antinode, strictly speaking, the energy of the bending vibration is not zero. Since it can be further damped, bending vibration can be more effectively suppressed, and even if some variation occurs in the size of the vibrating piece in the X-axis direction, bending vibration can be sufficiently suppressed. Excellent effect.

8A and 8B are schematic views showing another structure of the resonator element according to the embodiment of the invention, in which FIG. 8A is a plan view of the resonator element, and FIG. 8B is P in FIG. 8A. It is -P sectional drawing.
(Structure of vibrating piece)
The resonator element 2 is a rectangle having the long side in the X-axis direction and the short side in the Z′-axis direction of the rotated Y-cut quartz crystal substrate. Both side surfaces 122 in the Z′-axis direction of the resonator element 2 are composed of four surfaces: a first crystal surface 24, a second crystal surface 25, a fourth crystal surface 27, and a fifth crystal surface 28. In addition, the resonator element 2 has a mesa structure including the thick central portion 13 as the vibrating portion 12 and a thin peripheral portion 14 around the outer periphery of the thick central portion 13.
Note that the side surface of the mesa portion that is the protruding portion formed on the + side in the Y′-axis direction of the resonator element 2 that is the thick central portion 13 is the second crystal plane 25 and the − side in the Z′-axis direction. The third crystal plane 26 is composed of two planes so that the boundary is spatially in contact with each other, and the + side in the Z′-axis direction is composed of the first crystal plane 24. The side surface of the mesa formed on the negative side in the Y′-axis direction of the resonator element 2 is point-symmetric with respect to this, and the positive side in the Z′-axis direction is such that the second crystal plane 25 and the third crystal plane 26 are mutually connected. The boundary is spatially in contact with two faces, and the negative side in the Z′-axis direction is the first crystal face 24.
This mesa shape can further improve the energy confinement effect of the thickness-shear vibration mode, which is the main vibration, and can further suppress the influence of the unnecessary mode and improve the frequency characteristics.

(Manufacturing method of vibrating piece)
Next, another method for manufacturing the resonator element according to the embodiment of the invention will be described with reference to a schematic cross-sectional view of one resonator element 2. The quartz substrate 10 will be described with an example using an AT cut quartz substrate.
FIG. 9 is a schematic cross-sectional view of the quartz substrate and the vibration piece in the manufacturing process of the outer shape processing of the vibration piece, and FIG. 10 is a schematic cross-sectional view of the vibration piece in the manufacturing process of the mesa processing performed after the outer shape processing of the vibration piece.
Etching is performed on the exposed surface of the quartz substrate 10 so that the unmasked quartz portion completely penetrates, and the two surfaces of the first crystal face 24 and the second crystal face 25 are formed on the side face 120 in the Z′-axis direction. Until the side surface composed of crystal faces is formed, the manufacturing method is the same as that shown in FIG. 3 (FIG. 9D).
Thereafter, mesa-shaped pattern masks 30c and 30d are formed on both the front and back main surfaces of the resonator element 201 on which the side surfaces constituted by two crystal planes are formed (FIG. 10E). Subsequently, etching is performed using an ammonium fluoride solution or the like to form a mesa shape. Etching for adjusting the step of the mesa is equivalent to thickness adjusting etching in the manufacturing process of FIG. Therefore, the shape of both side surfaces in the Z′-axis direction after etching is the same as the side surface shape formed by the manufacturing method of FIG.
That is, when the etching amount Md is less than 10%, both side surfaces 121 in the Z′-axis direction of the resonator element 202 are constituted by two crystal planes that are shapes before the mesa formation etching. Similarly, the region of the first crystal plane 24 tends to increase and the region of the second crystal plane 25 tends to decrease (FIG. 10 (f)).

Next, when the etching amount Md is 10% or more and less than 15%, both side surfaces 122 in the Z′-axis direction of the resonator element 203 are etched, and the main surface corresponding to the thickness T2 and the first crystal surface 24 The side surface shape is composed of four crystal planes including the new fourth crystal plane 27 and the fifth crystal plane 28 generated during the period (FIG. 10G).
When the etching is further performed and the etching amount Md is set to 15% or more, both side surfaces 123 of the vibrating piece 204 in the Z′-axis direction are newly formed between the first crystal plane 24 and the fifth crystal plane 28. As a result, six crystal planes 29 are formed, and the side surface is formed of five crystal planes (FIG. 10H).
Therefore, even in the resonator elements 202, 203, and 204 having a mesa shape, both side surfaces in the Z′-axis direction can be configured with two to five crystal planes in relation to the etching amount Md. .

Therefore, by increasing the etching amount Md, many crystal planes can be formed on both side surfaces in the Z′-axis direction, so that an energy confinement effect is exhibited, which is effective in reducing the CI value, and the mesa shape is also increased. By forming the resonator element, it is possible to further improve the energy confinement effect of the thickness-shear vibration mode, which is the main vibration, and to further suppress the influence of the unnecessary mode, and to manufacture a resonator element that can improve the frequency characteristics.
In addition, it seems that it is possible to increase the energy confinement effect in the X-axis direction by forming a new crystal plane on the side surface in the X-axis direction by applying an etching amount Md of 30% or more. Since the energy confinement effect of the thickness-shear vibration mode related to the mesa step is expected to be attenuated by increasing the thickness, the upper limit of the etching amount Md is considered to be about 30%.
Here, in one embodiment of the present invention, the etching amount Md is determined by the difference between the thickness of the vibrating portion 12 of the quartz substrate 10 before thickness adjustment etching and the thickness of the vibrating portion 12 of the quartz substrate 10 after thickness adjustment etching. It was explained that the amount of thickness to be removed was expressed as a ratio (%) to the thickness of the vibrating portion 12 of the quartz substrate 10 before thickness adjustment etching. However, in the case of the mesa type resonator element, the etching amount Md is the size of the step between the thick central portion 13 and the thin peripheral portion 14 and the thickness of the quartz substrate 10 before the thickness adjustment etching and the thin peripheral portion. The amount of thickness to be removed in the thin peripheral portion 14 region, which is a difference in thickness from the thickness 14, is expressed as a percentage (%) with respect to the thickness of the quartz substrate 10 before thickness adjustment etching.

  In the embodiment shown in FIG. 8 and FIG. 10, an example of a mesa shape with one step on the front and back main surfaces of the resonator element is shown. A multi-stage mesa shape or a multi-stage mesa shape may be provided on either the front or back main surface of the resonator element. In addition, although an example in which the mesa shape is a rectangle is shown, the shape is not limited to this, and the shape may be a circle or an ellipse.

11A and 11B are schematic views illustrating the configuration of a vibration element according to an embodiment of the present invention, in which FIG. 11A is a plan view of the vibration element, and FIG. 11B is a PP of FIG. 11A. It is sectional drawing.
The vibration element 3 includes a quartz substrate 10 having a vibrating portion 12, an excitation electrode 15 formed to face both main surfaces (front and back surfaces in the ± Y ′ direction) of the quartz substrate 10, a lead electrode 16, A pad electrode 17 and a connection electrode 18 are provided.
The lead electrode 16 extends from the excitation electrode 15 and is electrically connected to a pad electrode 17 formed at the end of the quartz substrate 10.
The pad electrodes 17 are formed so as to face the ends of both main surfaces of the quartz substrate 10, and are electrically connected to each other by connection electrodes 18 formed on the side surfaces 22 of the quartz substrate 10.

In the embodiment shown in FIG. 11A, an example in which the shape of the excitation electrode 15 formed so as to face the main surface of the substantially central portion of the vibrating portion 12 is rectangular is shown, but it is necessary to limit to this. Alternatively, the shape may be circular or elliptical.
In the case of the mesa type resonator element shown in FIGS. 8 and 10, the excitation electrode 15 is provided on the main surface of the thick central portion 13 to be the vibrating portion 12, and the pad electrode 17 provided on the thin peripheral portion 14. And a lead electrode 16 that electrically connects the excitation electrode 15 to each other.

12A and 12B are schematic views showing the configuration of the vibrator according to the embodiment of the present invention. FIG. 12A is a plan view in which the lid member is omitted, and FIG. 12B is a longitudinal sectional view. The vibrator 5 includes a vibration element 3, a package body 40 formed in a rectangular box shape for housing the vibration element 3, a lid member 49 made of metal, ceramic, glass, or the like. Yes.
As shown in FIG. 12, the package body 40 is formed by laminating a first substrate 41, a second substrate 42, a third substrate 43, a seal ring 44, and a mounting terminal 45. Yes. A plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 41. The third substrate 43 is an annular body from which the central portion is removed, and a seal ring 44 such as Kovar is formed on the upper peripheral edge of the third substrate 43.
The third substrate 43 and the second substrate 42 form a recess (cavity) that houses the vibration element 3. A plurality of element mounting pads 47 that are electrically connected to the mounting terminals 45 by conductors 46 are provided at predetermined positions on the upper surface of the second substrate 42. The element mounting pad 47 is disposed so as to correspond to the pad electrode 17 formed at the end of the crystal substrate 10 when the vibration element 3 is mounted.

When the vibration element 3 is supported and fixed, first, the pad electrode 17 of the vibration element 3 is placed on the element mounting pad 47 coated with the conductive adhesive 38 and a load is applied.
Next, in order to cure the conductive adhesive 38, it is placed in a high temperature furnace at a predetermined temperature for a predetermined time. After the conductive adhesive 38 is cured, an annealing process is performed, and the frequency is adjusted by adding mass to the excitation electrode 15 or reducing the mass. Thereafter, the lid member 49 is placed on the seal ring 44 formed on the upper surface of the third substrate 43 of the package body 40, and the lid member 49 is seam welded and sealed in a vacuum or in an atmosphere of nitrogen gas. The vibrator 5 is completed.
Alternatively, there is also a method in which the lid member 49 is placed on the low melting point glass applied to the upper surface of the package body 40 and melted and adhered. Also in this case, the cavity of the package is evacuated or filled with an inert gas such as nitrogen gas, and the vibrator 5 is completed.

  In the above-described embodiment of the vibrator 5, an example in which a laminated plate is used for the package body 40 has been described. However, a vibrator using a single-layer ceramic plate for the package body 40 and a cap that has been drawn on the lid body. 5 may be configured.

FIG. 13 is a longitudinal sectional view showing a modification of the vibrator according to the embodiment of the present invention. FIG. 13 (a) is a longitudinal sectional view of Modification 1, and FIG. 13 (b) is a longitudinal section of Modification 2. FIG.
As shown in FIG. 13, the vibrators 5a and 5b are vibration elements 3, a thermistor 70 that functions as a temperature sensor (temperature sensing element), and a container in which the vibration element 3 and the thermistor 70 are mounted (contained). Package 40a, 40b.
FIG. 13A shows a structure in which the vibration element 3 and the thermistor 70 are mounted (accommodated) in a recess (cavity) formed by the third substrate 43 and the second substrate 42a.
Further, in FIG. 13B, the vibration element 3 is mounted (stored) in the recessed portion (cavity) formed by the third substrate 43 and the second substrate 42b, and the first substrate 41b and the second substrate 42b. The thermistor 70 is mounted in a recess (cavity) formed by the substrate 42b.

The thermistor 70 is, for example, a chip-type (cuboid-shaped) temperature sensing element (temperature sensing resistance element), and is a resistor whose electrical resistance changes greatly with respect to temperature changes.
As the thermistor 70, for example, a thermistor called an NTC (Negative Temperature Coefficient) thermistor whose resistance decreases with increasing temperature is used. NTC thermistors are frequently used as temperature sensors because the change in resistance value with respect to the change in temperature is proportional.
The thermistor 70 is housed (mounted) in the packages 40a and 40b, detects the temperature in the vicinity of the vibration element 3, and outputs it to a temperature compensation circuit (not shown). It plays a function that contributes to the correction.

14A and 14B are schematic views showing the configuration of an electronic device according to an embodiment of the present invention. FIG. 14A is a plan view in which a lid member is omitted, and FIG. 14B is a longitudinal sectional view. .
The electronic device 7 includes a package body 50, a lid member 49, the vibration element 3, an IC component 51 on which an oscillation circuit for exciting the vibration element 3 is mounted, a variable capacitance element whose capacitance changes according to voltage, and a resistance which depends on temperature. And at least one electronic component 52 such as a changing thermistor or inductor.

As shown in FIG. 14, the package body 50 is formed by stacking a first substrate 61, a second substrate 62, and a third substrate 63. A plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 61. The 2nd board | substrate 62 and the 3rd board | substrate 63 are formed with the annular body from which the center part was removed.
The first substrate 61, the second substrate 62, and the third substrate 63 form a recess (cavity) that accommodates the vibration element 3, the IC component 51, the electronic component 52, and the like. A plurality of element mounting pads 47 that are electrically connected to the mounting terminals 45 by conductors 46 are provided at predetermined positions on the upper surface of the second substrate 62. The position of the element mounting pad 47 is arranged so as to correspond to the pad electrode 17 formed at the end of the crystal substrate 10 when the vibration element 3 is mounted.

  The pad electrode 17 of the vibration element 3 is placed on the element mounting pad 47 of the package body 50 to which the conductive adhesive 38 is applied, and the conductive adhesive 38 is cured at a predetermined temperature. Conduction with the mounting pad 47 is intended. The IC component 51 is fixed at a predetermined position of the package body 50, and the terminal of the IC component 51 and the electrode terminal 55 of the package body 50 are connected by the bonding wire BW. Further, the electronic component 52 is placed at a predetermined position of the package body 50 and connected to the conductor 46 using a metal bump or the like. The package body 50 is filled with an inert gas such as vacuum or nitrogen, and the package body 50 is sealed with a lid member 49 to complete the electronic device 7.

  Also, stable oscillation can be achieved by configuring an oscillation circuit including a temperature compensation circuit and a voltage control circuit using a variable capacitance element whose capacitance changes with voltage and an electronic component 52 such as a thermistor or inductor whose resistance changes with temperature. An electronic device 7 such as a temperature-compensated oscillator or a voltage-controlled oscillator having characteristics can be configured.

Next, an electronic device (an electronic device of the present invention) to which the vibration element according to an embodiment of the present invention is applied will be described in detail based on FIGS. 15 to 17.
FIG. 15 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 100. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a vibration element 3 that functions as a filter, a resonator, a reference clock, and the like.

  FIG. 16 is a perspective view illustrating a configuration of a mobile phone (including PHS) as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a vibration element 3 that functions as a filter, a resonator, or the like.

FIG. 17 is a perspective view illustrating a configuration of a digital still camera as an electronic apparatus including the vibration element according to the embodiment of the invention. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 100 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 100 displays an object as an electronic image. Functions as a viewfinder. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.
When the photographer confirms the subject image displayed on the display unit 100 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 includes a vibration element 3 that functions as a filter, a resonator, or the like.

  Note that the electronic device including the vibration element according to the embodiment of the present invention includes, for example, an inkjet in addition to the personal computer (mobile personal computer) in FIG. 15, the mobile phone in FIG. 16, and the digital still camera in FIG. 17. Dispenser (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game machine, word processor , Workstations, videophones, crime prevention TV monitors, electronic binoculars, POS terminals, medical equipment (eg, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasonic diagnostic devices, electronic endoscopes), fish detectors, Various measuring instruments and instruments (example If, gages for vehicles, aircraft, and ships), can be applied to a flight simulator or the like.

FIG. 18 is a perspective view schematically showing an automobile 2106 as a specific example of a moving object including the vibration element according to the embodiment of the invention. In this figure, the vibration element 3 is built in an electronic control unit 2108 for controlling a tire 2109 and mounted on a vehicle body 2107.
The automobile 2106 is equipped with a vibrator or electronic device having the vibration element according to the present invention. For example, a keyless entry, an immobilizer, a car navigation system, a car air conditioner, an antilock brake system (ABS), an air The present invention can be widely applied to electronic control units (ECUs) 2108 such as backs, tire pressure monitoring systems (TPMS), engine controls, battery monitors for hybrid vehicles and electric vehicles, and vehicle body attitude control systems.

  1, 2, 101, 102, 103, 104, 201, 202, 203, 204 ... vibrating piece, 3 ... vibrating element, 5 ... vibrator, 7 ... electronic device, 10 ... quartz substrate, 12 ... vibrating part, 13 ... Thick central part, 14 ... Thin peripheral part, 15 ... Excitation electrode, 16 ... Lead electrode, 17 ... Pad electrode, 18 ... Connection electrode, 20, 21, 22, 23, 120, 121, 122, 123 ... Side, 24 ... 1st crystal face, 25 ... 2nd crystal face, 26 ... 3rd crystal face, 27 ... 4th crystal face, 28 ... 5th crystal face, 29 ... 6th crystal face, 30a, 30b , 30c, 30d ... mask, 31 ... chrome (Cr), 32 ... gold (Au), 33 ... resist, 38 ... conductive adhesive, 40 ... package body, 41 ... first substrate, 42 ... second substrate 43 ... Third substrate 44 ... Seal ring 45 ... Mounting terminal 46 ... conductor, 47 ... element mounting pad, 49 ... lid member, 50 ... package body, 51 ... IC component, 52 ... electronic component, 55 ... electrode terminal, 61 ... first substrate, 62 ... second substrate, 63 3rd board 70 70 Thermistor 100 Display unit 1100 Personal computer 1102 Keyboard 1104 Main unit 1106 Display unit 1200 Mobile phone 1202 Operation buttons 1204 Earpiece 1206 ... Mouthpiece 1300 ... Digital still camera 1302 ... Case 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Memory 1312 ... Video signal output terminal 1314 ... Input / output terminal 1430 ... TV monitor 1440 ... Personal computer, 2106 ... automobile, 2107 ... car body, 21 8 ... electronic control unit, 2109 ... tire.

Claims (19)

Mainly includes a plane including an X-axis that is a crystal axis of quartz and a Z′-axis that is obtained by rotating the Z-axis that is the crystal axis toward the −Y-axis side of the Y-axis that is the crystal axis with the X-axis as a rotation axis. Prepare a rotating Y-cut quartz substrate having a thickness on the Y′-axis direction obtained by rotating the Y-axis, which is the crystal axis, to the −Z-axis side of the Z-axis, which is the crystal axis, with the X-axis as the rotation axis And a process of
After the thickness of the rotated Y-cut quartz substrate in the Y′-axis direction is reduced by 10% or more and at least one of the two sides intersecting the Z′-axis of the rotated Y-cut quartz substrate is etched. Etching the rotated Y-cut quartz substrate so that at least four surfaces are formed;
A method of manufacturing a resonator element comprising: Mainly includes a plane including an X-axis that is a crystal axis of quartz and a Z′-axis that is obtained by rotating the Z-axis that is the crystal axis toward the −Y-axis side of the Y-axis that is the crystal axis with the X-axis as a rotation axis. Prepare a rotating Y-cut quartz substrate having a thickness on the Y′-axis direction obtained by rotating the Y-axis, which is the crystal axis, to the −Z-axis side of the Z-axis, which is the crystal axis, with the X-axis as the rotation axis And a process of
The thickness of the rotated Y-cut quartz substrate in the Y′-axis direction is reduced within a range of 10% or more and less than 15%, and at least one of two side surfaces intersecting the Z′-axis of the rotated Y-cut quartz substrate. Etching the rotated Y-cut quartz substrate such that at least four surfaces are formed after etching the side surfaces;
A method of manufacturing a resonator element comprising: Mainly includes a plane including an X-axis that is a crystal axis of quartz and a Z′-axis that is obtained by rotating the Z-axis that is the crystal axis toward the −Y-axis side of the Y-axis that is the crystal axis with the X-axis as a rotation axis. Prepare a rotating Y-cut quartz substrate having a thickness on the Y′-axis direction obtained by rotating the Y-axis, which is the crystal axis, to the −Z-axis side of the Z-axis, which is the crystal axis, with the X-axis as the rotation axis And a process of
Etching the rotated Y-cut quartz substrate such that at least four surfaces are formed after etching at least one of the two sides intersecting the Z ′ axis of the rotated Y-cut quartz substrate; ,
And the etching step is performed by wet etching, and
A first mask is disposed on the principal surface on one side in the Y′-axis direction of the rotated Y-cut quartz substrate, and the Z ′ relative to the first mask on the principal surface on the other side in the Y′-axis direction. the second mask is disposed such that a position shifted to one side in the axial direction, the rotation Y cut quartz substrate is wet etched through the first mask and the second mask, the outer shape of the vibration piece Forming, and
Removing the first mask and the second mask;
Wet etching the rotating Y-cut quartz substrate to form the at least four surfaces on at least one of the side surfaces;
A method of manufacturing a resonator element comprising: In claim 1 or claim 2,
The method of manufacturing a resonator element, wherein the etching step is performed by wet etching. In claim 4,
The etching step includes
A first mask is disposed on the principal surface on one side in the Y′-axis direction of the rotated Y-cut quartz substrate, and the Z ′ relative to the first mask on the principal surface on the other side in the Y′-axis direction. A second mask is disposed so as to be shifted to one side in the axial direction, the rotary Y-cut quartz crystal substrate is wet-etched through the first mask and the second mask, and the outer shape of the vibrating piece is formed. Forming, and
Removing the first mask and the second mask;
Forming the at least four surfaces on at least one of the side surfaces by wet etching the vibration piece;
A method of manufacturing a resonator element comprising: In claim 3 or claim 5,
When the thickness of the rotated Y-cut quartz substrate is T (μm), the shift amount Δz (μm) of the second mask with respect to the first mask is
0.75 × T × 0.8 ≦ Δz ≦ 0.75 × T × 1.2
A method of manufacturing a resonator element characterized by satisfying the relationship: In any one of Claims 1 thru | or 6,
The method of manufacturing a resonator element, wherein the at least four surfaces are arranged in the Y′-axis direction. Mainly includes a plane including an X-axis that is a crystal axis of quartz and a Z′-axis that is obtained by rotating the Z-axis that is the crystal axis toward the −Y-axis side of the Y-axis that is the crystal axis with the X-axis as a rotation axis. A rotating Y-cut quartz substrate having a thickness in the Y′-axis direction obtained by rotating the Y-axis that is the crystal axis toward the −Z-axis side of the Z-axis that is the crystal axis with the X-axis as the rotation axis And
At least one of the two side surfaces intersecting the Z ′ axis of the rotated Y-cut quartz substrate includes at least four surfaces;
In the side surface having the main surface on one side in the Y′-axis direction, the main surface on the other side in the Y′-axis direction, and the at least four surfaces,
An oscillating piece characterized in that an angle formed by two surfaces whose ends are connected to each other is an obtuse angle. In claim 8,
At least one of the side surfaces includes five surfaces. In claim 9,
The resonator element according to claim 5, wherein the five surfaces are arranged in the Y′-axis direction. In claim 8 or claim 9,
The resonator element according to claim 1, wherein the at least four surfaces are arranged in the Y′-axis direction. In any one of Claims 8 to 11,
A protrusion is provided on at least one of the principal surfaces of the rotating Y-cut quartz crystal substrate on the one side in the Y′-axis direction and the principal surface on the other side in the Y′-axis direction. Vibrating piece characterized by. It is arranged excitation electrodes in the Y 'the main surface of one side in the axial direction and the Y' the main surface of the axial direction of the other side of the resonator element according to any one of claims 8 to 11 A vibrating element characterized by comprising: An excitation electrode is provided on the principal surface on one side in the Y′-axis direction and the principal surface on the other side in the Y′-axis direction of the resonator element according to claim 12 at a position overlapping the projecting portion in plan view. A vibrating element characterized by being arranged. In claim 13 or claim 14,
A pad electrode electrically connected to the excitation electrode;
The vibration element, wherein the pad electrode is disposed at a position overlapping the side surface having the at least four surfaces in plan view. The vibration element according to any one of claims 13 to 15,
A package containing the vibration element;
A vibrator characterized by comprising: The vibration element according to any one of claims 13 to 15,
Electronic components,
A container in which the vibration element and the electronic component are mounted;
An electronic device comprising:   An electronic device comprising the vibration element according to any one of claims 13 to 15.   A moving body comprising the vibration element according to any one of claims 13 to 15.

Images