Piezoelectric Vibration Device

Abstract

To provide a piezoelectric vibration device capable of sufficiently performing hermetic sealing of a vibration part with an annular seal part.SOLUTION: In a piezoelectric vibration device, annular seal paths 115 and 116 for hermetically sealing a vibration part 11 of a crystal diaphragm 10 are provided between a first seal member 20 and the crystal diaphragm 10 and between a second seal member 30 and the crystal diaphragm 10. Narrow parts 115a, 115b, 116a and 116b of the seal paths 115 and 116 are overlapped with at least one of a portion of first and second terminals 22 and 23 and a portion of external electrode terminals 32 and 32 in a planar view.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a piezoelectric vibration device such as a piezoelectric vibrator. [Background technology]

[0002] In recent years, the operating frequencies of various electronic devices have become higher and their packages have become smaller (especially lower profile). As a result, there is a demand for piezoelectric vibration devices (e.g., quartz crystal resonators, quartz crystal oscillators, etc.) to accommodate the higher frequencies and smaller packages.

[0003] In this type of piezoelectric vibration device, the housing is configured as a roughly rectangular parallelepiped package. This package is configured of a first sealing member and a second sealing member made of, for example, glass or quartz, and a piezoelectric vibration plate made of, for example, quartz and having excitation electrodes formed on both main surfaces, and the first sealing member and the second sealing member are laminated and bonded via the piezoelectric vibration plate. Then, the vibration part (excitation electrode) of the piezoelectric vibration plate arranged inside the package (internal space) is hermetically sealed (for example, Patent Document 1). Hereinafter, such a laminated form of a piezoelectric vibration device is referred to as a sandwich structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-252051 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the piezoelectric vibration device as described above, annular sealing parts that hermetically seal the vibration part of the piezoelectric vibration plate are formed between the first sealing member and the piezoelectric vibration plate, and between the second sealing member and the piezoelectric vibration plate, and are hermetically sealed, for example, by pressure diffusion bonding the package. However, as the package becomes smaller, the area in which the sealing part is formed is gradually narrowing, and if the sealing part is formed in such a narrow area, there is a possibility that the sealing part will not hermetically seal the vibration part insufficiently. For example, such a problem is particularly of concern in a configuration in which wiring patterns such as wiring routes are arranged in parallel around the sealing part.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a piezoelectric vibration device that is capable of sufficiently hermetically sealing a vibration portion with an annular sealing portion. [Means for solving the problem]

[0007] The present invention provides a means for solving the above-mentioned problems as follows. That is, the present invention provides a piezoelectric diaphragm having a first excitation electrode formed on one main surface of a substrate and a second excitation electrode formed on the other main surface of the substrate to be paired with the first excitation electrode, a first sealing member that covers the first excitation electrode of the piezoelectric diaphragm, and a second sealing member that covers the second excitation electrode of the piezoelectric diaphragm, and the first sealing member and the piezoelectric diaphragm are bonded together, thereby providing a piezoelectric diaphragm having a first excitation electrode formed on one main surface of the substrate and a second excitation electrode formed on the other main surface of the substrate, and a first sealing member that covers the second excitation electrode of the piezoelectric diaphragm, and the first sealing member and the piezoelectric diaphragm are bonded together, A roughly rectangular parallelepiped package is formed. In a piezoelectric vibration device having an internal space in which a vibration portion of the piezoelectric vibration plate including the first excitation electrode and the second excitation electrode is hermetically sealed, The above package ofa top surface terminal formed on a main surface of the first sealing member that does not face the internal space and an external electrode terminal formed on a main surface of the second sealing member that does not face the internal space are electrically connected via side wiring formed on a side surface; inter-laminate wiring connected to the side wiring is provided between the first sealing member and the piezoelectric diaphragm and between the second sealing member and the piezoelectric diaphragm; annular sealing portions that hermetically seal the vibration portion of the piezoelectric diaphragm are provided between the first sealing member and the piezoelectric diaphragm and between the second sealing member and the piezoelectric diaphragm; the inter-laminate wiring is provided around the sealing portion at a predetermined distance from the sealing portion; a narrow portion that is narrower than a portion not along the inter-laminate wiring is provided in a portion of the sealing portion that is along the inter-laminate wiring in a planar view; and the narrow portion overlaps at least one of a portion of the top surface terminal and a portion of the external electrode terminal in a planar view.

[0008] According to the above configuration, the narrow portion overlaps, in a planar view, with at least one of a portion of the top terminal and a portion of the external electrode terminal. Therefore, when manufacturing a package for the piezoelectric vibration device by pressure diffusion bonding or the like, pressure can be sufficiently transmitted to the narrow portion in the overlapping portion in a planar view, so that the narrow portion of the sealing portion can be pressurized as uniformly as possible, and the vibration portion can be sufficiently hermetically sealed by the annular sealing portion.

[0009] In the above configuration, In a plan view, the narrow portion is in contact with at least one of a portion of the upper surface terminal and a portion of the external electrode terminal. The length of the overlapping portion in a direction along the outer periphery of the sealing portion is preferably 50% or more of the length of the narrow portion in a direction along the outer periphery of the sealing portion. With this configuration, by ensuring that the overlapping portion in a plan view is as large as possible, the narrow portion of the sealing portion can be pressurized as uniformly as possible, and the vibration portion can be sufficiently hermetically sealed by the annular sealing portion.

[0010] In the above configuration, the narrow portion is, in a plan view, a part of the upper surface terminal and a part of the external electrode terminal over its entire area. At least oneWith this configuration, pressure can be sufficiently transmitted to the narrow portion of the sealing portion, and the non-pressurized area of ​​the narrow portion can be reduced as much as possible. This allows the narrow portion to be pressurized as uniformly as possible, and the vibration portion can be sufficiently hermetically sealed by the annular sealing portion.

[0011] In the above configuration, the sealing portion is The above Located along the outer periphery of the package, and having a long side portion and a short side portion, The narrow portion is The above It is preferable that the narrow portion is provided on the long side portion. With this configuration, even if the narrow portion is provided on the long side portion of the sealing portion, pressure can be reliably transmitted to the narrow portion in the overlapping portion in a plan view. This makes it possible to apply pressure to the narrow portion as uniformly as possible, and to sufficiently hermetically seal the vibration portion with the annular sealing portion.

[0012] In the above configuration, the first sealing member and the piezoelectric diaphragm are joined by Au-Au bonding, and the second sealing member and the piezoelectric diaphragm are joined by Au-Au bonding, The thickness of the sealing portion between the first sealing member and the piezoelectric diaphragm is 1 μm or less, A gap between the first sealing member and the piezoelectric diaphragm is 1 μm or less, and the thickness of the sealing portion between the second sealing member and the piezoelectric diaphragm is 1 μm or less; It is preferable that the gap between the second sealing member and the piezoelectric vibration plate is 1 μm or less. With this configuration, it is possible to easily accommodate a reduction in the height of the piezoelectric vibration device. Effect of the Invention

[0013] According to the piezoelectric vibration device of the present invention, the narrow portion overlaps at least one of a portion of the top terminal and a portion of the external electrode terminal when viewed in a plan view. Therefore, when manufacturing a package for the piezoelectric vibration device by pressure diffusion bonding or the like, the narrow portion of the sealing portion can be pressurized as uniformly as possible, and the vibration portion can be sufficiently hermetically sealed by the annular sealing portion. [Brief description of the drawings]

[0014] [Figure 1]FIG. 1 is a schematic diagram showing the configuration of a crystal resonator according to this embodiment. [Diagram 2] FIG. 2 is a schematic plan view of the first main surface side of the first sealing member of the quartz crystal unit. [Diagram 3] FIG. 3 is a schematic plan view of the second principal surface side of the first sealing member of the quartz crystal unit. [Figure 4] FIG. 4 is a schematic plan view of the first main surface side of the quartz crystal plate of the quartz crystal unit. [Diagram 5] FIG. 5 is a schematic plan view of the second main surface side of the quartz crystal plate of the quartz crystal unit. [Figure 6] FIG. 6 is a schematic plan view of the first main surface side of the second sealing member of the quartz crystal unit. [Figure 7] FIG. 7 is a schematic plan view of the second principal surface side of the second sealing member of the quartz crystal unit. [Figure 8] FIG. 8 is a schematic side view of the -X direction side of the quartz crystal resonator. [Figure 9] FIG. 9 is a schematic side view of the +X direction side of the quartz crystal unit. [Figure 10] FIG. 10 is a diagram showing the positional relationship in plan view between the narrow portion of the seal path between the first sealing member and the quartz crystal plate, the first and second terminals, and the metal film. [Figure 11] FIG. 11 is a diagram showing the positional relationship in plan view between the narrow portion of the seal path between the first sealing member and the quartz crystal plate, and the external electrode terminals. [Figure 12] FIG. 12 is a diagram showing the positional relationship in plan view between the narrow portion of the seal path between the second sealing member and the quartz crystal plate, the first and second terminals, and the metal film. [Figure 13] FIG. 13 is a diagram showing the positional relationship in plan view between the narrow portion of the seal path between the second sealing member and the quartz crystal plate, and the external electrode terminals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following preferred embodiments, a piezoelectric resonator device to which the present invention is applied is a quartz crystal resonator.

[0016] First, the basic structure of the quartz crystal unit 100 according to this embodiment will be described. As shown in Fig. 1, the quartz crystal unit 100 is configured to include a quartz crystal vibration plate (piezoelectric vibration plate) 10, a first sealing member 20, and a second sealing member 30. In this quartz crystal unit 100, the quartz crystal vibration plate 10 and the first sealing member 20 are bonded together, and the quartz crystal vibration plate 10 and the second sealing member 30 are bonded together to form a package having a substantially rectangular sandwich structure. That is, in the quartz crystal unit 100, the first sealing member 20 and the second sealing member 30 are bonded to both main surfaces of the quartz crystal vibration plate 10, respectively, to form an internal space (cavity) of the package, and the vibration unit 11 (see Figs. 4 and 5) is hermetically sealed in this internal space.

[0017] The crystal unit 100 according to this embodiment has a package size of, for example, 0.8×0.6 mm or 1.0×0.0 mm, and is small and low-profile. In addition, in order to achieve the small size, the package does not form castellations, but uses side wiring, etc., to be described later, to achieve electrical continuity of the electrodes. The crystal unit 100 is electrically connected to an external circuit board (not shown) provided externally via solder.

[0018] Next, the quartz crystal plate 10, the first sealing member 20, and the second sealing member 30 in the above-mentioned quartz crystal unit 100 will be described with reference to Figs. 1 to 7. Note that the following describes each of the components that are configured as separate units that are not joined together. Figs. 2 to 7 merely show examples of the configuration of the quartz crystal plate 10, the first sealing member 20, and the second sealing member 30, and do not limit the present invention.

[0019] As shown in FIG. 4 and FIG. 5, the quartz crystal vibrating plate 10 is a piezoelectric substrate made of quartz crystal, and both main surfaces (first main surface 101, second main surface 102) are formed as flat and smooth surfaces (mirror finish). In this embodiment, an AT-cut quartz crystal plate that performs thickness-shear vibration is used as the quartz crystal vibrating plate 10. In the quartz crystal vibrating plate 10 shown in FIG. 4 and FIG. 5, both main surfaces 101, 102 of the quartz crystal vibrating plate 10 are XZ' planes. In this XZ' plane, the direction parallel to the short side direction (short side direction) of the quartz crystal vibrating plate 10 is the X-axis direction, and the direction parallel to the long side direction (long side direction) of the quartz crystal vibrating plate 10 is the Z'-axis direction. The AT-cut is a processing technique in which the artificial quartz crystal is cut at an angle of 35°15' around the X-axis with respect to the Z-axis, which is one of the three crystal axes of the artificial quartz crystal, that is, the electric axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). In an AT-cut quartz plate, the X-axis coincides with the crystal axis of the quartz. The Y'-axis and Z'-axis coincide with axes that are inclined at approximately 35°15' from the Y-axis and Z-axis of the quartz crystal (this cutting angle may be changed somewhat within the range to adjust the frequency-temperature characteristics of the AT-cut quartz plate). The Y'-axis and Z'-axis directions correspond to the cutting direction when the AT-cut quartz plate is cut.

[0020] A pair of excitation electrodes (first excitation electrode 111, second excitation electrode 112) are formed on both main surfaces 101, 102 of the quartz crystal vibration plate 10. The quartz crystal vibration plate 10 has a vibration part 11 formed in a substantially rectangular shape, an outer frame part 12 surrounding the outer periphery of the vibration part 11, and a holding part 13 that holds the vibration part 11 by connecting the vibration part 11 and the outer frame part 12. That is, the quartz crystal vibration plate 10 is configured such that the vibration part 11, the outer frame part 12, and the holding part 13 are integrally provided. The holding part 13 extends (protrudes) from only one corner of the vibration part 11 located in the +X direction and the -Z' direction to the outer frame part 12 in the -Z' direction. A cutout part 10a formed by cutting out the quartz crystal vibration plate 10 is provided between the vibration part 11 and the outer frame part 12. In this embodiment, the quartz crystal vibration plate 10 is provided with only one holding portion 13 that connects the vibration portion 11 and the outer frame portion 12, and the cutout portion 10a is formed continuously so as to surround the outer periphery of the vibration portion 11.

[0021] The first excitation electrode 111 is provided on the first main surface 101 side of the vibration section 11, and the second excitation electrode 112 is provided on the second main surface 102 side of the vibration section 11. The first excitation electrode 111 and the second excitation electrode 112 are connected with lead-out wiring (first lead-out wiring 113, second lead-out wiring 114) for connecting these excitation electrodes to external electrode terminals formed on the bottom surface of the package. The first lead-out wiring 113 is led out from the first excitation electrode 111 and connected to a connection bonding pattern 14 formed on the outer frame section 12 via a holding section 13. The second lead-out wiring 114 is led out from the second excitation electrode 112 and connected to a connection bonding pattern 15 formed on the outer frame section 12 via a holding section 13.

[0022] Both main surfaces (first main surface 101, second main surface 102) of the quartz crystal vibration plate 10 are provided with a vibration plate-side sealing portion for bonding the quartz crystal vibration plate 10 to the first sealing member 20 and the second sealing member 30. A vibration plate-side first bonding pattern 121 is formed as the vibration plate-side sealing portion of the first main surface 101, and a vibration plate-side second bonding pattern 122 is formed as the vibration plate-side sealing portion of the second main surface 102. The vibration plate-side first bonding pattern 121 and the vibration plate-side second bonding pattern 122 are provided on the outer frame portion 12 and are formed in an annular shape in a plan view. The outer peripheral edge of the vibration plate-side first bonding pattern 121 is provided close to the outer peripheral edge of the first main surface 101 of the quartz crystal vibration plate 10 (outer frame portion 12). The outer peripheral edge of the vibration plate-side second bonding pattern 122 is provided close to the outer peripheral edge of the second main surface 102 of the quartz crystal vibration plate 10 (outer frame portion 12).

[0023] Interlaminar wiring bonding patterns 181, 182 are formed on the outer periphery of the vibration plate first bonding pattern 121 on the first main surface 101 of the quartz crystal vibrating plate 10. The interlaminar wiring bonding patterns 181, 182 are not connected to the vibration plate first bonding pattern 121 and are provided at a predetermined interval from the vibration plate first bonding pattern 121. The interlaminar wiring bonding patterns 181, 182 are provided on the long side portions (here, portions along the Z' axis direction) of the quartz crystal vibrating plate 10. The interlaminar wiring bonding pattern 181 is provided on the -X direction side and +Z' direction side of the first main surface 101 of the quartz crystal vibrating plate 10 and is connected to the first side surface wiring 171 described later. The interlaminar wiring bonding pattern 182 is provided on the +X direction side and -Z' direction side of the first main surface 101 of the quartz crystal vibrating plate 10 and is connected to the second side surface wiring 172 described later.

[0024] In this embodiment, narrow width portions 121a and 121b are provided in portions of the diaphragm-side first bonding pattern 121 that are aligned (facing) with the interlaminar wiring bonding patterns 181 and 182 in a plan view, and that are narrower in width (here, width in the X-axis direction) than portions that are not aligned with the interlaminar wiring bonding patterns 181 and 182. The narrow width portions 121a and 121b are formed by indenting the outer peripheral edge of the diaphragm-side first bonding pattern 121 inward, and the interlaminar wiring bonding patterns 181 and 182 are disposed in the recesses formed by indenting the diaphragm-side first bonding pattern 121.

[0025] In addition, interlaminar wiring bonding patterns 183, 184 are formed on the outer periphery of the vibration plate-side second bonding pattern 122 on the second main surface 102 of the quartz crystal vibrating plate 10. The interlaminar wiring bonding patterns 183, 184 are not connected to the vibration plate-side second bonding pattern 122, and are provided at a predetermined interval from the vibration plate-side second bonding pattern 122. The interlaminar wiring bonding patterns 183, 184 are provided on the long side portions (here, portions along the Z'-axis direction) of the quartz crystal vibrating plate 10. The interlaminar wiring bonding pattern 183 is provided on the -X-direction side and +Z'-direction side portions of the second main surface 102 of the quartz crystal vibrating plate 10, and is connected to the first side surface wiring 171 described later. The interlaminar wiring bonding pattern 184 is provided on the +X-direction side and -Z'-direction side portions of the second main surface 102 of the quartz crystal vibrating plate 10, and is connected to the second side surface wiring 172 described later.

[0026] In this embodiment, narrow width portions 122a, 122b are provided in portions of the diaphragm-side second bonding pattern 122 that are aligned (facing) with the interlaminar wiring bonding patterns 183, 184 in a plan view, and that are narrower in width (here, width in the X-axis direction) than portions that are not aligned with the interlaminar wiring bonding patterns 183, 184. The narrow width portions 122a, 122b are formed by indenting the outer peripheral edge of the diaphragm-side second bonding pattern 122 inward, and the interlaminar wiring bonding patterns 183, 184 are disposed in the recesses formed by indenting the diaphragm-side second bonding pattern 122.

[0027] As shown in Fig. 4 and Fig. 5, the quartz crystal vibration plate 10 has one through hole penetrating between the first main surface 101 and the second main surface 102. Specifically, the first through hole 162 is provided in the outer frame portion 12, on the inner periphery side of the vibration plate-side first bonding pattern 121 and the vibration plate-side second bonding pattern 122. The first through hole 162 is also provided on one side in the Z'-axis direction of the vibration portion 11 (the -Z'-direction side in Figs. 4 and 5). Around the first through hole 162, a connection bonding pattern 124 is formed on the first main surface 101 side, and a connection bonding pattern 15 is formed on the second main surface 102 side.

[0028] In the first through-hole 162, a through electrode for achieving electrical continuity between the electrodes formed on the first main surface 101 and the second main surface 102 is formed along the inner wall surface of the first through-hole 162. The central portion of the first through-hole 162 is a hollow through portion that penetrates between the first main surface 101 and the second main surface 102. Note that electrical continuity between the electrodes on the first main surface 101 and the second main surface 102 may be achieved by means other than the through-hole through electrode (for example, wiring formed on the inner wall surface of the outer frame portion 12, etc.).

[0029] 4 and 5, two side wirings are formed on the side of the quartz-crystal vibrating plate 10. Specifically, a first side wiring 171 is formed on the side 103 on the -X direction side of the quartz-crystal vibrating plate 10. A second side wiring 172 is formed on the side 104 on the +X direction side of the quartz-crystal vibrating plate 10.

[0030] The first side surface wiring 171 is formed on a portion of the +Z' direction side of the side surface 103 on the -X direction side of the quartz crystal vibrating plate 10. The first side surface wiring 171 is connected to an inter-layer wiring bonding pattern 181 provided on the first main surface 101 of the quartz crystal vibrating plate 10. The first side surface wiring 171 is connected to an inter-layer wiring bonding pattern 183 provided on the second main surface 202 of the quartz crystal vibrating plate 10.

[0031] The second side surface wiring 172 is formed on a portion of the -Z' direction side of the side surface 104 on the +X direction side of the quartz crystal plate 10. The second side surface wiring 172 is connected to an inter-layer wiring bonding pattern 182 provided on the first main surface 101 of the quartz crystal plate 10. The second side surface wiring 172 is connected to an inter-layer wiring bonding pattern 184 provided on the second main surface 202 of the quartz crystal plate 10.

[0032] 4 and 5, two internal wirings are formed on the inner wall surface of the outer frame portion 12 of the quartz-crystal vibrating plate 10. Specifically, a first internal wiring 173 is formed on the inner wall surface 105 on the -X direction side of the outer frame portion 12 of the quartz-crystal vibrating plate 10. A second internal wiring 174 is formed on the inner wall surface 106 on the +X direction side of the outer frame portion 12 of the quartz-crystal vibrating plate 10.

[0033] The first internal wiring 173 is provided with a predetermined width in the center of the inner wall surface 105 on the -X direction side of the outer frame portion 12. The first internal wiring 173 is connected to a diaphragm-side first bonding pattern 121 provided on the first main surface 101 of the quartz-crystal vibration plate 10. The first internal wiring 173 is connected to a diaphragm-side second bonding pattern 122 provided on the second main surface 102 of the quartz-crystal vibration plate 10.

[0034] The second internal wiring 174 is provided with a predetermined width in the center of the inner wall surface 106 on the +X direction side of the outer frame portion 12. The second internal wiring 174 is connected to a diaphragm-side first bonding pattern 121 provided on the first main surface 101 of the quartz-crystal vibration plate 10. The second internal wiring 174 is connected to a diaphragm-side second bonding pattern 122 provided on the second main surface 102 of the quartz-crystal vibration plate 10. The first internal wiring 173 and the second internal wiring 174 are arranged to face each other with the vibration portion 11 in between.

[0035] 2 and 3, the first sealing member 20 is a rectangular parallelepiped substrate formed from a single AT-cut quartz crystal plate, and the second main surface 202 (the surface to be bonded to the quartz crystal vibrating plate 10) of this first sealing member 20 is formed as a flat and smooth surface (mirror-finished). Although the first sealing member 20 does not have a vibrating part, by using an AT-cut quartz crystal plate like the quartz crystal vibrating plate 10, the thermal expansion coefficients of the quartz crystal vibrating plate 10 and the first sealing member 20 can be made the same, and thermal deformation of the quartz crystal unit 100 can be suppressed. Furthermore, the orientations of the X-axis, Y-axis, and Z'-axis in the first sealing member 20 are also the same as those of the quartz crystal vibrating plate 10.

[0036] As shown in FIG. 2, the first and second terminals 22 and 23 for wiring and the metal film 28 for shielding (earth connection) are formed on the first main surface 201 (the outer main surface not facing the crystal vibration plate 10) of the first sealing member 20 as top surface terminals formed on the top surface of the package. The first and second terminals 22 and 23 for wiring are provided as wiring for electrically connecting the first and second excitation electrodes 111 and 112 of the crystal vibration plate 10 to the external electrode terminal 32 of the second sealing member 30. The first and second terminals 22 and 23 are provided at both ends in the Z′-axis direction, with the first terminal 22 provided on the +Z′-direction side and the second terminal 23 provided on the −Z′-direction side. The first and second terminals 22 and 23 are formed to extend in the X-axis direction. The first terminal 22 and the second terminal 23 are formed in a substantially rectangular shape. The first terminal 22 extends to an end of the first main surface 201 on the -X direction side, and is connected to a third side surface wiring 271, which will be described later. The second terminal 23 extends to an end of the first main surface 201 on the +X direction side, and is connected to a fourth side surface wiring 272, which will be described later.

[0037] The metal film 28 is provided between the first and second terminals 22, 23 and is disposed at a predetermined interval from the first and second terminals 22, 23. The metal film 28 is provided in almost all areas of the first main surface 201 of the first sealing member 20 where the first and second terminals 22, 23 are not formed. The metal film 28 is provided from the end in the +X direction to the end in the -X direction of the first main surface 201 of the first sealing member 20. The metal film 28 extends to the end in the -X direction of the first main surface 201 and is connected to a fifth side surface wiring 273 described later. The metal film 28 also extends to the end in the +X direction of the first main surface 201 and is connected to a sixth side surface wiring 274 described later.

[0038] 2 and 3, the first sealing member 20 has two through holes formed therein, penetrating between the first main surface 201 and the second main surface 202. Specifically, second and third through holes 212, 213 are provided in the +Z' and -Z' directions in FIGS.

[0039] In the second and third through holes 212 and 213, through electrodes for achieving electrical continuity between the electrodes formed on the first main surface 201 and the second main surface 202 are formed along the inner wall surfaces of the second and third through holes 212 and 213. The central portions of the second and third through holes 212 and 213 are hollow through portions that penetrate between the first main surface 201 and the second main surface 202. The through electrode of the second through hole 212 is electrically connected to the first terminal 22. The through electrode of the third through hole 213 is electrically connected to the second terminal 23.

[0040] On the second main surface 202 of the first sealing member 20, a sealing member-side first bonding pattern 24 is formed as a sealing member-side first sealing portion for bonding to the quartz crystal vibration plate 10. The sealing member-side first bonding pattern 24 is formed in an annular shape in a plan view. The outer periphery of the sealing member-side first bonding pattern 24 is provided close to the outer periphery of the second main surface 202 of the first sealing member 20. In addition, on the second main surface 202 of the first sealing member 20, a connection bonding pattern 261 is formed around the second through hole 212, and a connection bonding pattern 262 is formed around the third through hole 213. Furthermore, a connection bonding pattern 263 is formed on the opposite side (-Z' direction side) of the long axis direction of the first sealing member 20 with respect to the connection bonding pattern 261, and the connection bonding pattern 261 and the connection bonding pattern 263 are connected by a wiring pattern 27.

[0041] In addition, interlaminar wiring junction patterns 281 and 282 are formed on the second main surface 202 of the first sealing member 20 on the outer periphery side of the sealing member side first junction pattern 24. The interlaminar wiring junction patterns 281 and 282 are not connected to the sealing member side first junction pattern 24 and are provided at a predetermined interval from the sealing member side first junction pattern 24. The interlaminar wiring junction patterns 281 and 282 are provided on the long side portions (here, portions along the Z' axis direction) of the first sealing member 20. The interlaminar wiring junction pattern 281 is provided on the -X direction side and +Z' direction side of the second main surface 202 of the first sealing member 20 and is connected to a third side surface wiring 271 described later. The interlaminar wiring junction pattern 282 is provided on the +X direction side and -Z' direction side of the second main surface 202 of the first sealing member 20 and is connected to a fourth side surface wiring 272 described later.

[0042] In this embodiment, narrow width portions 24a, 24b are provided in portions (facing portions) of the sealing member-side first bonding pattern 24 that are aligned with the interlaminar wiring bonding patterns 281, 282 in a plan view, and that are narrower in width (here, width in the X-axis direction) than portions that are not aligned with the interlaminar wiring bonding patterns 281, 282. The narrow width portions 24a, 24b are formed by indenting the outer peripheral edge of the sealing member-side first bonding pattern 24 inward, and the interlaminar wiring bonding patterns 281, 282 are disposed in the recesses formed by indenting the sealing member-side first bonding pattern 24.

[0043] 2 and 3, four side surface wirings are formed on a side surface of the first sealing member 20. Specifically, a third side surface wiring 271 and a fifth side surface wiring 273 are formed on a side surface 203 on the -X direction side of the first sealing member 20. A fourth side surface wiring 272 and a sixth side surface wiring 274 are formed on a side surface 204 on the +X direction side of the first sealing member 20.

[0044] The third side surface wiring 271 is formed on a portion on the +Z' direction side of the side surface 203 on the -X direction side of the first sealing member 20. The third side surface wiring 271 is connected to a first terminal 22 provided on the first main surface 201 of the first sealing member 20. The third side surface wiring 271 is connected to an interlayer wiring junction pattern 281 provided on the second main surface 202 of the first sealing member 20.

[0045] The fourth side surface wiring 272 is formed on a portion on the -Z' direction side of the side surface 204 on the +X direction side of the first sealing member 20. The fourth side surface wiring 272 is connected to the second terminal 23 provided on the first main surface 201 of the first sealing member 20. The fourth side surface wiring 272 is connected to an interlayer wiring junction pattern 282 provided on the second main surface 202 of the first sealing member 20.

[0046] The fifth side surface wiring 273 is formed on a portion on the -Z' direction side of the side surface 203 on the -X direction side of the first sealing member 20. The fifth side surface wiring 273 is connected to the metal film 28 provided on the first main surface 201 of the first sealing member 20. The fifth side surface wiring 273 is connected to the sealing member side first bonding pattern 24 provided on the second main surface 202 of the first sealing member 20.

[0047] The sixth side surface wiring 274 is formed on a portion on the +Z' direction side of the side surface 204 on the +X direction side of the first sealing member 20. The sixth side surface wiring 274 is connected to the metal film 28 provided on the first main surface 201 of the first sealing member 20. The sixth side surface wiring 274 is connected to the sealing member side first bonding pattern 24 provided on the second main surface 202 of the first sealing member 20.

[0048] 6 and 7, the second sealing member 30 is a rectangular parallelepiped substrate formed from a single AT-cut quartz crystal plate, and a first main surface 301 (the surface to be bonded to the quartz crystal vibration plate 10) of this second sealing member 30 is formed as a flat and smooth surface (mirror-finished). Note that, like the quartz crystal vibration plate 10, the second sealing member 30 also uses an AT-cut quartz crystal plate, and it is preferable that the orientations of the X-axis, Y-axis, and Z'-axis are the same as those of the quartz crystal vibration plate 10.

[0049] A sealing member-side second bonding pattern 31 is formed on the first main surface 301 of the second sealing member 30 as a sealing member-side second sealing portion for bonding to the quartz crystal vibration plate 10. The sealing member-side second bonding pattern 31 is formed in an annular shape in a plan view. The outer periphery of the sealing member-side second bonding pattern 31 is provided close to the outer periphery of the first main surface 301 of the second sealing member 30.

[0050] In addition, interlaminar wiring junction patterns 381 and 382 are formed on the first main surface 301 of the second sealing member 30 on the outer periphery side of the sealing member side second junction pattern 31. The interlaminar wiring junction patterns 381 and 382 are not connected to the sealing member side second junction pattern 31 and are provided at a predetermined interval from the sealing member side second junction pattern 31. The interlaminar wiring junction patterns 381 and 382 are provided on the long side portions (here, portions along the Z' axis direction) of the second sealing member 30. The interlaminar wiring junction pattern 381 is provided on the -X direction side and +Z' direction side of the first main surface 301 of the second sealing member 30 and is connected to a seventh side surface wiring 371 described later. The interlaminar wiring junction pattern 382 is provided on the +X direction side and -Z' direction side of the first main surface 301 of the second sealing member 30 and is connected to an eighth side surface wiring 372 described later.

[0051] In this embodiment, narrow width portions 31a, 31b are provided in portions of the sealing member side second bonding pattern 31 that are aligned (facing) with the interlaminar wiring bonding patterns 381, 382 in a plan view, and that are narrower in width (here, width in the X-axis direction) than portions that are not aligned with the interlaminar wiring bonding patterns 381, 382. The narrow width portions 31a, 31b are formed by indenting the outer periphery of the sealing member side second bonding pattern 31 inward, and the interlaminar wiring bonding patterns 381, 382 are disposed in the recesses formed by indenting the sealing member side second bonding pattern 31.

[0052] Four external electrode terminals 32 are provided on the second main surface 302 (the outer main surface not facing the quartz crystal vibrating plate 10) of the second sealing member 30, which are electrically connected to an external circuit board provided outside the quartz crystal vibrating device 100. The external electrode terminals 32 are located at four corners (corner portions) of the second main surface 302 of the second sealing member 30. The external electrode terminals 32 are provided along the internal space of the package of the quartz crystal vibrating device 100 in a plan view, and are formed in a substantially L-shape. The external electrode terminals 32 are provided at positions overlapping with the outer frame portion 12 of the quartz crystal vibrating plate 10 described above in a plan view.

[0053] 6 and 7, four side surface wirings are formed on a side surface of second sealing member 30. Specifically, seventh side surface wiring 371 and ninth side surface wiring 373 are formed on side surface 303 on the -X direction side of second sealing member 30. Eighth side surface wiring 372 and tenth side surface wiring 374 are formed on side surface 304 on the +X direction side of second sealing member 30.

[0054] The seventh side surface wiring 371 is formed on a portion on the +Z' direction side of the side surface 303 on the -X direction side of the second sealing member 30. The seventh side surface wiring 371 is connected to an interlayer wiring junction pattern 381 provided on the first main surface 301 of the second sealing member 30. The seventh side surface wiring 371 is connected to an external electrode terminal 32 provided on the second main surface 302 of the second sealing member 30.

[0055] The eighth side surface wiring 372 is formed on a portion on the -Z' direction side of the side surface 304 on the +X direction side of the second sealing member 30. The eighth side surface wiring 372 is connected to an interlayer wiring junction pattern 382 provided on the first main surface 301 of the second sealing member 30. The eighth side surface wiring 372 is connected to an external electrode terminal 32 provided on the second main surface 302 of the second sealing member 30.

[0056] The ninth side surface wiring 373 is formed on a portion on the -Z' direction side of the side surface 303 on the -X direction side of the second sealing member 30. The ninth side surface wiring 373 is connected to the sealing member side second bonding pattern 31 provided on the first main surface 301 of the second sealing member 30. The ninth side surface wiring 373 is connected to the external electrode terminal 32 provided on the second main surface 302 of the second sealing member 30.

[0057] The tenth side surface wiring 374 is formed on a portion on the +Z' direction side of the side surface 304 on the +X direction side of the second sealing member 30. The tenth side surface wiring 374 is connected to the sealing member side second bonding pattern 31 provided on the first main surface 301 of the second sealing member 30. The tenth side surface wiring 374 is connected to the external electrode terminal 32 provided on the second main surface 302 of the second sealing member 30.

[0058] In the quartz crystal unit 100 including the quartz crystal vibration plate 10, the first sealing member 20, and the second sealing member 30 configured as above, the quartz crystal vibration plate 10 and the first sealing member 20 are diffusion bonded in a state where the first vibration plate-side bonding pattern 121 and the first sealing member-side bonding pattern 24 are overlapped, and the quartz crystal vibration plate 10 and the second sealing member 30 are diffusion bonded in a state where the second vibration plate-side bonding pattern 122 and the second sealing member-side bonding pattern 31 are overlapped, thereby manufacturing a sandwich-structured package as shown in Figs. 1, 8, and 9. At this time, the diffusion bonding is performed by applying pressure to the package (pressurized diffusion bonding). As a result, the internal space of the package, that is, the storage space of the vibration part 11, is hermetically sealed.

[0059] In the quartz crystal vibrator 100, the sealing portions (seal paths) 115, 116 that hermetically seal the vibration portion 11 of the quartz crystal vibrating plate 10 are formed in an annular shape in a plan view. The seal path 115 is formed by diffusion bonding (Au-Au bonding) of the above-mentioned vibration plate side first bonding pattern 121 and the sealing member side first bonding pattern 24, and the inner edge shape of the seal path 115 is formed into a substantially octagonal shape. The outer edge shape of the seal path 115 is formed into a substantially rectangular shape, and the outer periphery of the seal path 115 is disposed close to the outer periphery of the package. At this time, the narrow width portions 115a, 115b of the seal path 115 are formed by diffusion bonding (Au-Au bonding) of the narrow width portions 121a, 122b of the vibration plate side first bonding pattern 121 and the narrow width portions 24a, 24b of the sealing member side first bonding pattern 24.

[0060] Similarly, the seal path 116 is formed by diffusion bonding (Au-Au bonding) of the above-mentioned diaphragm-side second bonding pattern 122 and the sealing member-side second bonding pattern 31, and the inner edge shape of the seal path 116 is formed to be approximately octagonal. The outer edge shape of the seal path 116 is formed to be approximately rectangular, and the outer periphery of the seal path 116 is disposed close to the outer periphery of the package. At this time, the narrow width parts 116a and 116b of the seal path 116 are formed by diffusion bonding (Au-Au bonding) of the narrow width parts 122a and 122b of the diaphragm-side second bonding pattern 122 and the narrow width parts 31a and 31b of the sealing member-side second bonding pattern 31.

[0061] In the quartz crystal unit 100 in which the seal paths 115, 116 are formed by diffusion bonding in this manner, the first sealing member 20 and the quartz crystal plate 10 have a gap of 1.00 μm or less, and the second sealing member 30 and the quartz crystal plate 10 have a gap of 1.00 μm or less. In other words, the thickness of the seal path 115 between the first sealing member 20 and the quartz crystal plate 10 is 1.00 μm or less, and the thickness of the seal path 116 between the second sealing member 30 and the quartz crystal plate 10 is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au-Au bonding of this embodiment). As a comparative example, the thickness of a conventional metal paste sealing material using Sn is 5 μm to 20 μm.

[0062] The above-mentioned connection bonding patterns and interlaminar wiring bonding patterns are also diffusion bonded in a state of being superimposed. The connection bonding patterns and the interlaminar wiring bonding patterns are bonded to each other, and thus electrical conduction is obtained between the first excitation electrode 111, the second excitation electrode 112, and the external electrode terminal 32 in the quartz crystal resonator 100. Specifically, the first excitation electrode 111 is connected to the external electrode terminal 32 via the first lead wiring 113, the wiring pattern 27, the second through hole 212, the first terminal 22, the third side wiring 271, the first interlaminar wiring 117, the first side wiring 171, the second interlaminar wiring 118, and the seventh side wiring 371 in this order. The first interlaminar wiring 117 is a wiring disposed between the first sealing member 20 and the quartz crystal vibrating plate 10. The first interlayer wiring 117 is formed by diffusion bonding between an interlayer wiring bonding pattern 281 formed on the second main surface 202 of the first sealing member 20 and an interlayer wiring bonding pattern 181 formed on the first main surface 101 of the quartz crystal vibrating plate 10. As shown in FIG. 8, the third side surface wiring 271 is connected to the end of the first interlayer wiring 117 on the +Z' direction side, and the first side surface wiring 171 is connected to the end of the first interlayer wiring 117 on the -Z' direction side. The second interlayer wiring 118 is a wiring disposed between the layers of the quartz crystal vibrating plate 10 and the second sealing member 30. The second interlayer wiring 118 is formed by diffusion bonding between an interlayer wiring bonding pattern 183 formed on the second main surface 102 of the quartz crystal vibrating plate 10 and an interlayer wiring bonding pattern 381 formed on the first main surface 301 of the second sealing member 30. As shown in FIG. 8, the first side surface wiring 171 is connected to the end of the second interlayer wiring 118 on the -Z' direction side, and the seventh side surface wiring 371 is connected to the end of the second interlayer wiring 118 on the +Z' direction side.

[0063] The second excitation electrode 112 is connected to the external electrode terminal 32 via the second extraction wiring 114, the first through hole 162, the third through hole 213, the second terminal 23, the fourth side surface wiring 272, the third interlayer wiring 119, the second side surface wiring 172, the fourth interlayer wiring 120, and the eighth side surface wiring 372 in this order. The third interlayer wiring 119 is a wiring disposed between the first sealing member 20 and the quartz crystal vibration plate 10. The third interlayer wiring 119 is formed by diffusion bonding between the interlayer wiring bonding pattern 282 formed on the second main surface 202 of the first sealing member 20 and the interlayer wiring bonding pattern 182 formed on the first main surface 101 of the quartz crystal vibration plate 10. As shown in FIG. 9, the fourth side surface wiring 272 is connected to the end of the third interlayer wiring 119 on the -Z' direction side, and the second side surface wiring 172 is connected to the end of the third interlayer wiring 119 on the +Z' direction side. The fourth interlayer wiring 120 is a wiring disposed between the layers of the quartz-crystal vibrating plate 10 and the second sealing member 30. The fourth interlayer wiring 120 is formed by diffusion bonding between the interlayer wiring bonding pattern 184 formed on the second main surface 102 of the quartz-crystal vibrating plate 10 and the interlayer wiring bonding pattern 382 formed on the first main surface 301 of the second sealing member 30. As shown in FIG. 9, the second side surface wiring 172 is connected to the end of the fourth interlayer wiring 120 on the +Z' direction side, and the eighth side surface wiring 372 is connected to the end of the fourth interlayer wiring 120 on the -Z' direction side.

[0064] Furthermore, the metal film 28 is connected to earth (ground connection, using a part of the external electrode terminal 32) via the fifth side surface wiring 273, the seal path 115, the first internal wiring 173, the seal path 116, and the ninth side surface wiring 373 in this order. Similarly, the metal film 28 is connected to earth (ground connection, using a part of the external electrode terminal 32) via the sixth side surface wiring 274, the seal path 115, the second internal wiring 174, the seal path 116, and the tenth side surface wiring 374 in this order.

[0065] In this embodiment, the electrical conduction paths between the first and second excitation electrodes 111, 112 and the external electrode terminals 32, 32 are not electrically connected to the annular seal paths 115, 116.

[0066] Specifically, inside the annular seal paths 115 and 116 in plan view, the first excitation electrode 111 is electrically connected to the first terminal 22 on the first main surface 201 of the first sealing member 20 via the through electrode of the second through hole 212. The first terminal 22 is disposed across the inside and outside of the annular seal paths 115 and 116 in plan view. Then, outside the annular seal paths 115 and 116 in plan view, the first terminal 22 is electrically connected to the external electrode terminal 32 on the second main surface 302 of the second sealing member 30 via the side wirings 271, 171, and 371 formed on the package side surface of the crystal unit 100. Such an electrical conduction path between the first excitation electrode 111 and the external electrode terminal 32 is not electrically connected to the annular seal paths 115 and 116.

[0067] Similarly, inside the annular seal paths 115 and 116 in plan view, the second excitation electrode 112 is electrically connected to the second terminal 23 on the first main surface 201 of the first sealing member 20 via the through electrode of the first through hole 162 and the through electrode of the third through hole 213. The second terminal 23 is disposed across the inside and outside of the annular seal paths 115 and 116 in plan view. Then, outside the annular seal paths 115 and 116 in plan view, the second terminal 23 is electrically connected to the external electrode terminal 32 on the second main surface 302 of the second sealing member 30 via the side wirings 272, 172, and 372 formed on the package side surface of the crystal unit 100. Such an electrical conduction path between the second excitation electrode 112 and the external electrode terminal 32 is not electrically connected to the annular seal paths 115 and 116.

[0068] In the quartz crystal unit 100, the various bonding patterns described above are preferably formed by laminating a plurality of layers on the quartz crystal plate, with a Ti (titanium) layer and an Au (gold) layer being formed from the bottom layer side by vapor deposition or sputtering. In addition, if the other wiring and electrodes formed on the quartz crystal unit 100 have the same configuration as the bonding patterns, the bonding patterns, wiring, and electrodes can be patterned simultaneously, which is preferable.

[0069] In this embodiment, as shown in FIG. 10 and FIG. 11, the first interlayer wiring 117 is formed on the outer periphery of the seal path 115. The first interlayer wiring 117 is not connected to the seal path 115 and is provided at a predetermined interval from the seal path 115. The first interlayer wiring 117 is provided on a long side portion of the package (a portion along the Z′-axis direction in this case). The first interlayer wiring 117 is provided on a portion of the package on the −X-direction side and the +Z′-direction side in a plan view. A narrow width portion 115a is provided in a portion of the seal path 115 along the first interlayer wiring 117 in a plan view (a portion facing the first interlayer wiring 117), the narrow width portion 115a being narrower in width (here, width in the X-axis direction) than a portion not along the first interlayer wiring 117. The narrow width portion 115a is formed by recessing the outer periphery of the seal path 115 inward, and the first interlayer wiring 117 is disposed in the recessed portion of the seal path 115.

[0070] As shown in FIG. 10 and FIG. 11, the third interlayer wiring 119 is formed on the outer periphery of the seal path 115. The third interlayer wiring 119 is not connected to the seal path 115 and is provided at a predetermined interval from the seal path 115. The third interlayer wiring 119 is provided on a long side portion of the package (a portion along the Z′-axis direction in this case). The third interlayer wiring 119 is provided on a portion of the package on the +X-direction side and the −Z′-direction side in a plan view. A narrow width portion 115b is provided in a portion of the seal path 115 that is along the third interlayer wiring 119 in a plan view (a portion facing the third interlayer wiring 119) and has a narrower width (here, a width in the X-axis direction) than a portion that is not along the third interlayer wiring 119. The narrow width portion 115b is formed by recessing the outer periphery of the seal path 115 inward, and the third interlayer wiring 119 is disposed in the recessed portion of the seal path 115.

[0071] Similarly, as shown in FIG. 12 and FIG. 13, the second interlayer wiring 118 is formed on the outer periphery of the seal path 116. The second interlayer wiring 118 is not connected to the seal path 116 and is provided at a predetermined interval from the seal path 116. The second interlayer wiring 118 is provided on the long side of the package (here, the portion along the Z′-axis direction). The second interlayer wiring 118 is provided on the −X-direction side and +Z′-direction side of the package in a plan view. A narrow width portion 116a is provided in a portion of the seal path 116 that is along the second interlayer wiring 118 in a plan view (opposing portion) and has a narrower width (here, the width in the X-axis direction) than a portion that is not along the second interlayer wiring 118. The narrow width portion 116a is formed by recessing the outer periphery of the seal path 116 inward, and the second interlayer wiring 118 is disposed in the recessed portion formed by recessing the seal path 116.

[0072] As shown in FIG. 12 and FIG. 13, the fourth interlayer wiring 120 is formed on the outer periphery of the seal path 116. The fourth interlayer wiring 120 is not connected to the seal path 116 and is provided at a predetermined interval from the seal path 116. The fourth interlayer wiring 120 is provided on a long side portion of the package (a portion along the Z′-axis direction in this case). The fourth interlayer wiring 120 is provided on a portion of the package on the +X-direction side and the −Z′-direction side in a plan view. A narrow width portion 116b is provided in a portion of the seal path 116 that is along the fourth interlayer wiring 120 in a plan view (a portion facing the fourth interlayer wiring 120) and has a narrower width (here, a width in the X-axis direction) than a portion that is not along the fourth interlayer wiring 120. The narrow width portion 116b is formed by recessing the outer periphery of the seal path 116 inward, and the fourth interlayer wiring 120 is disposed in the recessed portion of the seal path 116 that is recessed.

[0073] In this embodiment, the narrow width parts 115a, 115b, 116a, and 116b of the seal paths 115 and 116 overlap at least one of the parts of the first and second terminals 22 and 23 and the parts of the external electrode terminals 32 and 32 in a plan view. The length of the overlapping parts in a direction along the outer periphery of the seal paths 115 and 116 (here, the Z'-axis direction) is 50% or more of the length of the narrow width parts 115a, 115b, 116a, and 116b in a direction along the outer periphery of the seal paths 115 and 116 in a plan view. In this case, the narrow width parts 115a, 115b, 116a, and 116b of the seal paths 115 and 116 overlap with the parts of the first and second terminals 22 and 23 and the parts of the external electrode terminals 32 and 32 in their entirety in a plan view. These points will be described with reference to Figs. 10 to 13.

[0074] FIG. 10 shows the positional relationship between the narrow portions 115a, 115b (shown by solid lines) of the seal path 115 and the first and second terminals 22, 23 (shown by dashed lines) in a plan view. FIG. 11 shows the positional relationship between the narrow portions 115a, 115b (shown by solid lines) of the seal path 115 and the external electrode terminals 32, 32 (shown by dashed lines) in a plan view. FIG. 12 shows the positional relationship between the narrow portions 116a, 116b (shown by solid lines) of the seal path 116 and the first and second terminals 22, 23 (shown by dashed lines) in a plan view. FIG. 13 shows the positional relationship between the narrow portions 116a, 116b (shown by solid lines) of the seal path 116 and the external electrode terminals 32, 32 (shown by dashed lines) in a plan view.

[0075] Specifically, as shown in Fig. 10, the narrow portion 115a of the seal path 115 between the first sealing member 20 and the quartz crystal plate 10 overlaps with a portion of the first terminal 22 in a plan view. As shown in Fig. 11, the narrow portion 115a overlaps with a portion of the external electrode terminal 32 in a plan view. The length of the overlapping portion in a direction along the outer periphery of the seal path 115 (here, the Z'-axis direction) is 50% or more of the length of the narrow portion 115a in a direction along the outer periphery of the seal path 115. In this case, the narrow portion 115a of the seal path 115 overlaps with either a portion of the first terminal 22 or a portion of the external electrode terminal 32 over its entire area in a plan view. That is, in a plan view, in a portion where the narrow portion 115a does not overlap with a portion of the first terminal 22, the narrow portion 115a overlaps with a portion of the external electrode terminal 32, and in a plan view, in a portion where the narrow portion 115a does not overlap with a portion of the external electrode terminal 32, the narrow portion 115a overlaps with a portion of the first terminal 22. In a plan view, the narrow portion 115a also overlaps with a portion of the first terminal 22 and a portion of the external electrode terminal 32. In addition, the narrow portion 115a also overlaps with a portion of the metal film 28 in a plan view.

[0076] 10, the narrow portion 115b of the seal path 115 between the first sealing member 20 and the quartz crystal plate 10 overlaps with a portion of the second terminal 23 in a plan view. As shown in FIG. 11, the narrow portion 115b overlaps with a portion of the external electrode terminal 32 in a plan view. The length of the overlapping portion in a direction along the outer periphery of the seal path 115 (here, the Z′-axis direction) is 50% or more of the length of the narrow portion 115b in a direction along the outer periphery of the seal path 115. In this case, the narrow portion 115b of the seal path 115 overlaps with either a portion of the second terminal 23 or a portion of the external electrode terminal 32 over its entire area in a plan view. That is, in a plan view, in a portion where narrow portion 115b does not overlap with a portion of second terminal 23, narrow portion 115b overlaps with a portion of external electrode terminal 32, and in a portion where narrow portion 115b does not overlap with a portion of external electrode terminal 32, narrow portion 115b overlaps with a portion of second terminal 23. In a plan view, narrow portion 115b also overlaps with a portion of both second terminal 23 and external electrode terminal 32. Note that narrow portion 115b also overlaps with a portion of metal film 28 in a plan view.

[0077] As shown in Fig. 12, the narrow portion 116a of the seal path 116 between the second sealing member 30 and the quartz crystal vibrating plate 10 overlaps with a portion of the first terminal 22 in a plan view. As shown in Fig. 13, the narrow portion 116a overlaps with a portion of the external electrode terminal 32 in a plan view. The length of the overlapping portion in a direction along the outer periphery of the seal path 116 (here, the Z'-axis direction) is 50% or more of the length of the narrow portion 116a in a direction along the outer periphery of the seal path 116. In this case, the narrow portion 116a of the seal path 116 overlaps with either a portion of the first terminal 22 or a portion of the external electrode terminal 32 over its entire area in a plan view. That is, in a plan view, in a portion where narrow portion 116a does not overlap with a portion of first terminal 22, narrow portion 116a overlaps with a portion of external electrode terminal 32, and in a plan view, in a portion where narrow portion 116a does not overlap with a portion of external electrode terminal 32, narrow portion 116a overlaps with a portion of first terminal 22. In addition, in a plan view, narrow portion 116a also overlaps with a portion of metal film 28.

[0078] 12, the narrow portion 116b of the seal path 116 between the second sealing member 30 and the quartz crystal vibrating plate 10 overlaps with a portion of the second terminal 23 in a plan view. As shown in FIG. 13, the narrow portion 116b overlaps with a portion of the external electrode terminal 32 in a plan view. The length of the overlapping portion in a direction along the outer periphery of the seal path 116 (here, the Z′-axis direction) is 50% or more of the length of the narrow portion 116b in a direction along the outer periphery of the seal path 116. In this case, the narrow portion 116b of the seal path 116 overlaps with either a portion of the second terminal 23 or a portion of the external electrode terminal 32 over its entire area in a plan view. That is, in a plan view, in a portion where narrow portion 116b does not overlap with a portion of second terminal 23, narrow portion 116b overlaps with a portion of external electrode terminal 32, and in a plan view, in a portion where narrow portion 116b does not overlap with a portion of external electrode terminal 32, narrow portion 116b overlaps with a portion of second terminal 23. In addition, in a plan view, narrow portion 116b also overlaps with a portion of metal film 28.

[0079] According to this embodiment, the narrow portions 115a, 115b, 116a, and 116b of the sealing paths 115, 116 overlap portions of the first and second terminals 22, 23 and portions of the external electrode terminals 32, 32 in a planar view. Therefore, when manufacturing a package of the quartz crystal vibrator 100 by pressure diffusion bonding, the narrow portions 115a, 115b, 116a, and 116b of the sealing paths 115, 116 can be pressurized as uniformly as possible, and the annular sealing paths 115, 116 can sufficiently hermetically seal the vibration portion 11.

[0080] Here, in the past, since the narrow portions 115a, 115b, 116a, and 116b of the seal paths 115, 116 are narrower than the other portions, when the package is pressurized from one side in the vertical direction, there is a problem that the pressure is not easily transmitted to the narrow portions 115a, 115b, 116a, and 116b, or the pressure is not uniformly applied to the narrow portions 115a, 115b, 116a, and 116b, and there is concern about poor airtightness of the vibrating portion 11. In particular, such a problem is prominent in a configuration in which wiring such as the above-mentioned first to fourth interlayer wirings 117-120 is arranged on the outer periphery side of the seal paths 115, 116.

[0081] However, in this embodiment, as described above, the narrow portions 115a, 115b, 116a, and 116b of the seal paths 115 and 116 overlap with parts of the first and second terminals 22 and 23 and parts of the external electrode terminals 32 and 32 in a plan view, so that pressure can be sufficiently transmitted to the narrow portions 115a, 115b, 116a, and 116b in the overlapping parts in a plan view, and pressure can be applied to the narrow portions 115a, 115b, 116a, and 116b as uniformly as possible. This ensures that diffusion bonding (Au-Au bonding) can be performed in the narrow portions 115a, 115b, 116a, and 116b, and the annular seal paths 115 and 116 can adequately hermetically seal the vibration portion 11. Furthermore, pressure can be effectively transmitted to the narrow width portions 115a, 115b, 116a, and 116b from both the upper and lower sides, and pressure can be effectively applied to the narrow width portions 115a, 115b, 116a, and 116b.

[0082] In this case, the length of the overlapping portion in a planar view in a direction along the outer peripheral edge of the seal paths 115, 116 (here, the Z'-axis direction) is 50% or more of the length of the narrow portions 115a, 115b, 116a, 116b in a direction along the outer peripheral edge of the seal paths 115, 116. Therefore, by ensuring that the overlapping portion in a planar view is as large as possible, the narrow portions 115a, 115b, 116a, 116b can be pressurized as evenly as possible, and the annular seal paths 115, 116 can sufficiently hermetically seal the vibration portion 11.

[0083] Furthermore, in plan view, the narrow width portions 115a, 115b, 116a, 116b of the seal paths 115, 116 overlap with either a portion of the first and second terminals 22, 23 or a portion of the external electrode terminals 32, 32 over their entire regions, so that pressure can be sufficiently transmitted to the narrow width portions 115a, 115b, 116a, 116b, and the non-pressurized regions of the narrow width portions 115a, 115b, 116a, 116b can be minimized. This allows the narrow width portions 115a, 115b, 116a, 116b to be pressurized as uniformly as possible, and the annular seal paths 115, 116 can adequately hermetically seal the vibration portion 11.

[0084] In this embodiment, the sealing paths 115, 116 are provided along the outer periphery of the package of the crystal unit 100, and the narrow width portions 115a, 115b, 116a, 116b are provided on the long side portions of the sealing paths 115, 116. Here, when pressure is applied to the package from one side in the vertical direction, each member is likely to bend in the long side direction and warp. Due to the influence of this warping, there is a possibility that the pressure applied to the sealing paths 115, 116 will be insufficient at both ends of the long side direction of each member.

[0085] However, in this embodiment, as described above, the narrow width portions 115a, 115b, 116a, and 116b of the seal paths 115 and 116 overlap with parts of the first and second terminals 22 and 23 and parts of the external electrode terminals 32 and 32 in a plan view, so that even if the narrow width portions 115a, 115b, 116a, and 116b are provided on the long side portions of the seal paths 115 and 116, pressure can be reliably transmitted to the narrow width portions 115a, 115b, 116a, and 116b in the overlapping portions in a plan view. This allows the narrow width portions 115a, 115b, 116a, and 116b to be pressurized as uniformly as possible, and the annular seal paths 115 and 116 can adequately hermetically seal the vibration portion 11.

[0086] In addition, the first sealing member 20 and the quartz vibration plate 10 are joined by Au-Au bonding, and the second sealing member 30 and the quartz vibration plate 10 are joined by Au-Au bonding, and the gap between the first sealing member 20 and the quartz vibration plate 10 and the gap between the second sealing member 30 and the quartz vibration plate 10 are 1 μm or less, so that the quartz vibration unit 100 can easily be made low-profile.

[0087] In this embodiment, the first excitation electrode 111 is electrically connected to a first terminal 22 formed on a first main surface 201 on the side not facing the internal space of the first sealing member 20 via a through electrode of a second through hole 212 provided in the first sealing member 20. The second excitation electrode 112 is electrically connected to a second terminal 23 formed on the first sealing member 20 via a through electrode of a first through hole 162 provided in the quartz crystal plate 10 and a through electrode of a third through hole 213 provided in the first sealing member 20. The first terminal 22 is electrically connected to an external electrode terminal (first external electrode terminal) 32 formed on a second main surface 302 on the side not facing the internal space of the second sealing member 30 via side wirings 271, 171, and 371 formed on the package side surface of the quartz crystal resonator 100. The second terminal 23 is electrically connected to an external electrode terminal (second external electrode terminal) 32 formed on the second main surface 302 of the second sealing member 30 via side wiring 272, 172, 372 formed on the package side surface of the quartz crystal unit 100.

[0088] According to this embodiment, the first and second excitation electrodes 111, 112 and the external electrode terminals 32, 32 are electrically connected via the first and second terminals 22, 23 formed on the first main surface 201 on the side not facing the internal space of the first sealing member 20, so that the electrical conduction path from the first and second excitation electrodes 111, 112 to the external electrode terminals 32, 32 can be lengthened and erosion by solder of the first and second excitation electrodes 111, 112 can be suppressed. In addition, an increase in the conduction resistance and the occurrence of disconnection due to solder erosion of the side wirings 271, 171, 371 and the side wirings 272, 172, 372 can be suppressed. Furthermore, since the first and second terminals 22, 23 and the external electrode terminals 32, 32 are electrically connected without using through holes, there is no need to form through holes in the outer peripheral edges of the quartz crystal vibration plate 10 and the first and second sealing members 20, 30, respectively, which makes it easy to miniaturize the quartz crystal vibrator 100.

[0089] In this case, the side wirings 271, 171, 371 and the side wirings 272, 172, 372 are formed without forming recesses (castellations) on the side surfaces of the package. This eliminates the need to form recesses on the side surfaces of the quartz crystal plate 10 and the first and second sealing members 20, 30, making it easy to miniaturize the quartz crystal unit 100.

[0090] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Also, all modifications within the scope and meaning equivalent to the claims are included.

[0091] The shapes and positions of the narrow width portions 115a, 115b, 116a, and 116b described above are merely examples, and narrow width portions may be provided on the short side portions of the seal paths 115 and 116, for example.

[0092] In the above embodiment, the narrow width portions 115a, 116a overlap the first terminal 22 and the metal film 28 in a plan view, but the narrow width portions 115a, 116a may overlap only one of the first terminal 22 and the metal film 28. In addition, the narrow width portions 115b, 116b overlap the second terminal 23 and the metal film 28 in a plan view, but the narrow width portions 115b, 116b may overlap only one of the second terminal 23 and the metal film 28.

[0093] In the above embodiment, the narrow portions 115a, 115b, 116a, 116b overlap with portions of the first and second terminals 22, 23 and portions of the external electrode terminals 32, 32 in a planar view from the inner end side to the outer end side. However, it is sufficient that the narrow portions 115a, 115b, 116a, 116b overlap with portions of the first and second terminals 22, 23 and portions of the external electrode terminals 32, 32 at at least one of the inner end side and outer end side. In this case, since pressure is less likely to be transmitted to the inner end portions of the narrow portions 115a, 115b, 116a, 116b, in order to ensure a stable airtight seal, it is preferable that at least the inner end portions of the narrow portions 115a, 115b, 116a, 116b overlap portions of the first and second terminals 22, 23 and portions of the external electrode terminals 32, 32 in a planar view.

[0094] In the above embodiment, the first to fourth interlayer wirings 117-120 are arranged on the outer periphery of the seal paths 115, 116, but the interlayer wirings may be arranged around the seal paths 115, 116 at a predetermined interval from the seal paths 115, 116, and may be arranged, for example, on the inner periphery of the seal paths 115, 116. Since the closer to the center of the package, the less susceptible to the effect of deflection and the more stable the diffusion bonding, it is preferable to arrange the narrow portions 115a, 115b, 116a, 116b of the seal paths 115, 116 on the inner periphery side by arranging the first to fourth interlayer wirings 117-120 on the outer periphery of the seal paths 115, 116 as in the above embodiment.

[0095] In the above embodiment, the quartz crystal vibration plate 10 is provided with only one holding portion (connecting portion) 13 that connects the vibration portion 11 and the outer frame portion 12, but two or more holding portions 13 may be provided.

[0096] In the above embodiment, the number of external electrode terminals 32 on the second main surface 302 of the second sealing member 30 is four, but this is not limited to this and the number of external electrode terminals 32 may be, for example, two, six, or eight. In addition, although a case has been described in which the present invention is applied to the quartz crystal resonator 100, this is not limited to this and the present invention may also be applied to, for example, a quartz crystal oscillator or the like.

[0097] In the above embodiment, the first sealing member 20 and the second sealing member 30 are formed from a quartz plate, but this is not limited to this, and the first sealing member 20 and the second sealing member 30 may be formed from, for example, glass. [Explanation of symbols]

[0098] 10 Quartz crystal plate (piezoelectric plate) 11 Vibration section 20 First sealing member 22 1st terminal (top terminal) 23 2nd terminal (top terminal) 30 Second sealing member 32 External electrode terminal 100 Quartz crystal unit (piezoelectric vibration device) 111 1st excitation electrode 112 2nd excitation electrode 115,116 Seal path (sealing part) 115a,115b,116a,116b Narrow part 117 First interlayer wiring 118 Second interlayer wiring 119 3rd interlayer wiring 120 4th interlayer wiring

Claims

1. a piezoelectric diaphragm having a first excitation electrode formed on one main surface of a substrate and a second excitation electrode formed on the other main surface of the substrate to be paired with the first excitation electrode; a first sealing member that covers the first excitation electrode of the piezoelectric diaphragm; a second sealing member that covers the second excitation electrode of the piezoelectric diaphragm; a piezoelectric vibration device in which a substantially rectangular parallelepiped package is formed by bonding the first sealing member to the piezoelectric vibration plate and bonding the second sealing member to the piezoelectric vibration plate, and an internal space is provided in which a vibration portion of the piezoelectric vibration plate including the first excitation electrode and the second excitation electrode is hermetically sealed; a top surface terminal formed on a main surface of the first sealing member that does not face the internal space and an external electrode terminal formed on a main surface of the second sealing member that does not face the internal space are electrically connected via a side wiring formed on a side surface of the package of the piezoelectric vibration device, an inter-lamination wiring connected to the side wiring is provided between the first sealing member and the piezoelectric diaphragm and between the second sealing member and the piezoelectric diaphragm; Between the first sealing member and the piezoelectric diaphragm, and between the second sealing member and the piezoelectric diaphragm, annular sealing portions are provided to hermetically seal a vibration portion of the piezoelectric diaphragm; the inter-layer wiring is provided around the sealing portion at a predetermined interval from the sealing portion, a narrow portion is provided in a portion of the sealing portion that is aligned with the inter-layer wiring in a plan view, the narrow portion being narrower than a portion of the sealing portion that is not aligned with the inter-layer wiring; A piezoelectric vibration device characterized in that, in a planar view, the narrow portion overlaps with at least one of a portion of the top surface terminal and a portion of the external electrode terminal.

2. 2. The piezoelectric vibration device according to claim 1, A piezoelectric vibration device characterized in that, when viewed in a planar view, the length of the narrow portion in a direction along the outer edge of the sealing portion at a portion where the narrow portion overlaps with at least one of a portion of the top surface terminal and a portion of the external electrode terminal is 50% or more of the length of the narrow portion in a direction along the outer edge of the sealing portion.

3. 3. The piezoelectric vibration device according to claim 1, A piezoelectric vibration device characterized in that, in a planar view, the narrow portion overlaps, over its entire area, with at least one of a portion of the top surface terminal and a portion of the external electrode terminal.

4. The piezoelectric vibration device according to any one of claims 1 to 3, A piezoelectric vibration device characterized in that the sealing portion is provided along the outer peripheral edge of the package and has a long side portion and a short side portion, and the narrow portion is provided on the long side portion of the sealing portion.

5. The piezoelectric vibration device according to any one of claims 1 to 4, the first sealing member and the piezoelectric diaphragm are joined by Au-Au bonding, and the second sealing member and the piezoelectric diaphragm are joined by Au-Au bonding; The thickness of the sealing portion between the first sealing member and the piezoelectric diaphragm is 1 μm or less, and the gap between the first sealing member and the piezoelectric diaphragm is 1 μm or less, A piezoelectric vibration device characterized in that the thickness of the sealing portion between the second sealing member and the piezoelectric vibration plate is 1 μm or less, and the gap between the second sealing member and the piezoelectric vibration plate is 1 μm or less.

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