Piezoelectric vibrator

Abstract

A piezoelectric vibrator (1) comprises: a piezoelectric vibration element (10) having a piezoelectric piece (11) and excitation electrodes (14a, 14b) configured so as to be able to apply voltage to the piezoelectric piece (11); a base member (30) on which the piezoelectric vibration element (10) is mounted; a lid member (40) that accommodates the piezoelectric vibration element (10) in an internal space provided between the lid member and the base member (30); and a joining part (50) that joins the base member (30) and the lid member (40) and seals the internal space. The joining part (50) contains an organic adhesive. When the direction intersecting the circumferential direction of the joining part (50) along a main surface (31A) of the base member (30) is defined as a width direction and the direction intersecting the main surface (31A) of the base member (30) is defined as a thickness direction, the relation of S / V / W ≤ 6 is established where the volume of the internal space is defined as an internal volume V, the dimension in the width direction of the joining part (50) is defined as a sealing width W, the dimension in the thickness direction of the joining part (50) is defined as a sealing thickness t, the dimension in the circumferential direction of the joining part (50) is defined as a circumferential length Lc, and the product of the sealing thickness t and the circumferential length Lc is defined as a sealing cross-sectional area S.

Description

Piezoelectric vibrator

[0001] The present invention relates to a piezoelectric vibrator.

[0002] Piezoelectric vibration elements are used in various electronic devices such as mobile communication terminals, communication base stations, home appliances, etc. as timing devices, sensors, oscillators, etc. A piezoelectric vibration element includes a piezoelectric plate having a pair of main surfaces and a pair of excitation electrodes provided on the pair of main surfaces of the piezoelectric plate.

[0003] For example, Patent Document 1 discloses a piezoelectric vibration component that includes a substrate, a piezoelectric vibrator held on the substrate, and a cap fixed to the substrate with an adhesive.

[0004] Patent No. 4947213

[0005] However, with the piezoelectric vibration part described in Patent Document 1, air or water vapor may enter through the adhesive, causing an increase in internal pressure or electrode oxidation, resulting in frequency fluctuations.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a piezoelectric vibrator that can suppress frequency fluctuations.

[0007] A piezoelectric vibrator according to one aspect of the present invention comprises a piezoelectric vibration element having a piezoelectric piece and an excitation electrode configured to be able to apply a voltage to the piezoelectric piece, a base member on which the piezoelectric vibration element is mounted, a lid member that houses the piezoelectric vibration element in an internal space provided between the base member and the lid member, and a joint that joins the base member and the lid member and seals the internal space, wherein the joint contains an organic adhesive, and when the direction along the main surface of the base member that intersects the circumferential direction of the joint is defined as the width direction and the direction that intersects the main surface of the base member is defined as the thickness direction, the volume of the internal space is defined as the internal volume V, the dimension of the joint in the width direction is defined as the sealing width W, the dimension of the joint in the thickness direction is defined as the sealing thickness t, the dimension of the joint in the circumferential direction is defined as the circumferential length Lc, and the product of the sealing thickness t and the circumferential length Lc is defined as the sealing cross-sectional area S, a relationship of S / V / W≦6 holds.

[0008] According to the present invention, it is possible to provide a piezoelectric vibrator capable of suppressing frequency fluctuations.

[0009] FIG. 1 is an exploded perspective view of a quartz crystal resonator according to a first embodiment. FIG. 2 is a cross-sectional view of a quartz crystal resonator according to a first embodiment. FIG. 3 is an enlarged cross-sectional view of a bonded portion of a quartz crystal resonator according to a first embodiment. FIG. 4 is a plan view of a quartz crystal resonator according to a first embodiment. FIG. 5 is a graph showing frequency fluctuations of examples based on the first embodiment. FIG. 6 is a cross-sectional view of a quartz crystal resonator according to a second embodiment. FIG. 7 is an enlarged cross-sectional view of a bonded portion of a quartz crystal resonator according to the second embodiment. FIG. 8 is a cross-sectional view of a quartz crystal resonator according to a third embodiment. FIG. 9 is an enlarged cross-sectional view of a bonded portion of a quartz crystal resonator according to a third embodiment. FIG. 10 is a cross-sectional view of a quartz crystal resonator according to a fourth embodiment. FIG. 11 is a graph showing fluctuations in equivalent series resistance of examples based on the first embodiment.

[0010] Hereinafter, embodiments of the present invention will be described. In the following description of the drawings, the same or similar components are denoted by the same or similar reference numerals. The drawings are illustrative, and the dimensions and shapes of each part are schematic. The technical scope of the present invention should not be interpreted as being limited to the embodiments.

[0011] For the sake of clarity, each drawing may be accompanied by a Cartesian coordinate system consisting of an X-axis, a Y'-axis, and a Z'-axis to clarify the interrelationships between the drawings and to aid in understanding the positional relationships of the various components. The X-axis, Y'-axis, and Z'-axis correspond to each other in each drawing. The X-axis, Y'-axis, and Z'-axis each correspond to the crystallographic axes of the quartz blank 11, which will be described later. The X-axis corresponds to the electrical axis (polarity axis) of the quartz, the Y-axis corresponds to the mechanical axis of the quartz, and the Z-axis corresponds to the optical axis of the quartz. The Y'-axis and Z'-axis are axes obtained by rotating the Y-axis and Z-axis counterclockwise around the X-axis by θ degrees when viewed from the positive direction of the X-axis.

[0012] In the following description, the direction parallel to the X-axis is referred to as the "X-axis direction," the direction parallel to the Y'-axis is referred to as the "Y'-axis direction," and the direction parallel to the Z'-axis is referred to as the "Z'-axis direction." The directions of the arrows on the X-axis, Y'-axis, and Z'-axis are referred to as "positive" or "+ (plus)," and the directions opposite the arrows are referred to as "negative" or "- (minus)." For convenience, the +Y'-axis direction will be described as the upward direction, and the -Y'-axis direction will be described as the downward direction, but the up-down orientation of the quartz crystal vibrating element 10 and the quartz crystal vibrator 1 is not limited to this. The plane specified by the X-axis and Z'-axis will be referred to as the Z'X plane, and the same applies to planes specified by the other axes.

[0013] First Embodiment First, the configuration of a quartz crystal resonator according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is an exploded perspective view of the quartz crystal resonator according to the first embodiment. Fig. 2 is a cross-sectional view of the quartz crystal resonator according to the first embodiment.

[0014] The quartz crystal resonator 1 includes a quartz crystal resonator element 10, a base member 30, a lid member 40, and a bonding portion 50. Hereinafter, the Y′-axis direction will be referred to as the “thickness direction” of the quartz crystal resonator element 10.

[0015] The crystal resonator 1 is used as a component of, for example, a temperature compensated crystal oscillator (TCXO), a voltage controlled crystal oscillator (VCXO), or an oven controlled crystal oscillator (OCXO).

[0016] The quartz crystal vibrating element 10 is an electromechanical energy conversion element that converts electrical energy into mechanical energy and vice versa by the piezoelectric effect.

[0017] The quartz crystal vibrating element 10 is excited at a predetermined frequency based on the applied alternating voltage. The quartz crystal vibrating element 10 is held so as to be vibrable in a vibration space provided between a base member 30 and a lid member 40. The main vibration of the quartz crystal vibrating element 10 is a thickness shear vibration mode.

[0018] The main vibration of the quartz crystal vibration element is not limited to the thickness shear vibration mode, but may be, for example, a thickness extensional vibration mode, a divergence vibration mode, a length vibration mode, or a bending vibration mode.

[0019] As shown in FIG. 1, the quartz crystal element 10 includes a thin quartz crystal element 11, a first excitation electrode 14a and a second excitation electrode 14b that constitute a pair of excitation electrodes, a first extraction electrode 15a and a second extraction electrode 15b that constitute a pair of extraction electrodes, and a first connection electrode 16a and a second connection electrode 16b that constitute a pair of connection electrodes.

[0020] The crystal blank 11 has an upper surface 11A and a lower surface 11B that face each other. The upper surface 11A is located on the side facing a ceiling wall portion 41 (described later) of the lid member 40. The lower surface 11B is located on the side facing the base member 30. The upper surface 11A and the lower surface 11B correspond to a pair of main surfaces of the crystal blank 11.

[0021] The quartz crystal blank 11 is, for example, an AT-cut quartz crystal. An AT-cut quartz crystal is formed so that the XZ' plane is the main surface and the thickness is in the direction parallel to the Y' axis. As an example, when the top surface 11A is viewed in a plan view in the thickness direction (hereinafter simply referred to as "plan view"), the shape of the quartz crystal blank 11 (hereinafter referred to as "planar shape") is rectangular with a pair of short sides extending in the Z'-axis direction and a pair of long sides extending in the X-axis direction. As an example, the shape of the quartz crystal blank 11 is a flat plate with a uniform thickness.

[0022] The planar shape of the crystal blank is not limited to the above. For example, the planar shape of the crystal blank may be rectangular with long sides extending in the Z'-axis direction and short sides extending in the X-axis direction, or square with sides extending in the Z'-axis direction and sides extending in the X-axis direction. The planar shape of the crystal blank may also be rectangular with sides extending in directions intersecting the Z-axis direction and the Z'-axis direction. The planar shape of the crystal blank may also be polygonal, circular, elliptical, or a combination thereof. Furthermore, the crystal blank is not limited to a flat shape. The crystal blank may have a mesa structure or an inverted mesa structure with irregularities on at least one of the top and bottom surfaces. The crystal blank may have a convex structure in which the amount of change in thickness changes continuously, or a bevel structure in which the amount of change in thickness changes discontinuously.

[0023] The AT-cut quartz crystal piece 11 is cut out with the XZ' plane as the main surface, with the Y'-axis and Z'-axis being the axes obtained by rotating the Y-axis and Z-axis around the X-axis by 35 degrees 15 minutes ± 1 minute 30 seconds from the Y-axis toward the Z-axis, out of the X-axis, Y-axis, and Z-axis which are the crystal axes of synthetic quartz crystal.

[0024] The quartz crystal vibrating element 10 using the AT-cut quartz crystal blank 11 has high frequency stability over a wide temperature range. The AT-cut quartz crystal vibrating element also has excellent aging characteristics and can be manufactured at low cost. Furthermore, the AT-cut quartz crystal vibrating element uses the thickness shear vibration mode as its primary vibration mode.

[0025] The cut angle of the quartz crystal blank is not limited to the above. The rotation angle of the Y'-axis and Z'-axis in the AT-cut quartz crystal blank 11 may be inclined within a range of -5 degrees or more or +15 degrees or less from 35 degrees 15 minutes. The cut angle of the quartz crystal blank may also be a cut other than the AT cut, such as a BT cut, a GT cut, or an SC cut. The primary vibration mode of the quartz crystal vibrating element is not limited to the thickness-shear vibration mode, and may be, for example, thickness-extensional vibration, diaphragm vibration, longitudinal vibration, or flexural vibration.

[0026] The first excitation electrode 14a and the second excitation electrode 14b apply an AC voltage to the crystal blank 11 to excite the crystal blank 11. The first excitation electrode 14a and the second excitation electrode 14b are provided in the center of the crystal blank 11 in a plan view. The first excitation electrode 14a is provided on the upper surface 11A, and the second excitation electrode 14b is provided on the lower surface 11B. The first excitation electrode 14a and the second excitation electrode 14b face each other in the Y'-axis direction, sandwiching the crystal blank 11 therebetween.

[0027] The first excitation electrode 14a has a rectangular planar shape with short sides extending in the Z'-axis direction and long sides extending in the X-axis direction. The first excitation electrode 14a has a thickness in the Y'-axis direction. The second excitation electrode 14b has a similar shape.

[0028] The planar shapes of the first excitation electrode and the second excitation electrode are not limited to those described above. The planar shapes of the first excitation electrode and the second excitation electrode may be rectangular having short sides extending in the X-axis direction, or may be square having sides extending in the X-axis direction and sides extending in the Z'-axis direction. The planar shapes of the first excitation electrode and the second excitation electrode may be rectangular having sides extending along directions intersecting the Z-axis direction and the Z'-axis direction. The planar shapes of the first excitation electrode and the second excitation electrode may be polygonal, circular, elliptical, or a combination thereof.

[0029] The first extraction electrode 15a electrically connects the first excitation electrode 14a to the first connection electrode 16a, and the second extraction electrode 15b electrically connects the second excitation electrode 14b to the second connection electrode 16b. The first extraction electrode 15a is provided across the top surface 11A and the bottom surface 11B of the crystal blank 11, and the second extraction electrode 15b is provided on the bottom surface 11B of the crystal blank 11.

[0030] The first connection electrode 16a and the second connection electrode 16b electrically connect the quartz crystal vibrating element 10 to the base member 30. The first connection electrode 16a and the second connection electrode 16b are provided on the lower surface 11B of the quartz crystal blank 11.

[0031] The first excitation electrode 14a, the first extraction electrode 15a, and the first connection electrode 16a are integrally formed. The same is true for the second excitation electrode 14b, the second extraction electrode 15b, and the second connection electrode 16b. A group of electrodes consisting of the first excitation electrode 14a, the first extraction electrode 15a, and the first connection electrode 16a is referred to as the first electrodes, and a group of electrodes consisting of the second excitation electrode 14b, the second extraction electrode 15b, and the second connection electrode 16b is referred to as the second electrodes.

[0032] The first electrode and the second electrode have a multilayer structure, for example, in which a base layer and a surface layer are stacked in this order. For example, the base layer is a chromium (Cr) layer that has good adhesion to the crystal blank 11, and the surface layer is a gold (Au) layer that has good chemical stability. The first electrode and the second electrode may contain titanium (Ti), aluminum (Al), molybdenum (Mo), or an aluminum-copper alloy (AlCu) mainly composed of aluminum (Al). The first electrode and the second electrode may also have a single-layer structure.

[0033] The base member 30 holds the quartz crystal vibrating element 10 so as to be capable of vibrating. The base member 30 includes a substrate 31, connection electrodes 33a and 33b, lead electrodes 34a and 34b, and external electrodes 35a, 35b, 35c, and 35d.

[0034] The base 31 is a plate-shaped insulator having an upper surface 31A and a lower surface 31B that face each other in the thickness direction. The upper surface 31A and the lower surface 31B correspond to a pair of main surfaces of the base 31. The upper surface 31A is located on the side facing the quartz vibrating element 10 and the lid member 40, and corresponds to the mounting surface on which the quartz vibrating element 10 is mounted. From the viewpoint of suppressing thermal stress acting from the base 31 on the quartz vibrating element 10 due to thermal history such as reflow, the base 31 is preferably made of a heat-resistant material. From the same viewpoint, the base 31 may be made of a material with a thermal expansion coefficient similar to that of the quartz blank 11. The base 31 is made of, for example, a ceramic substrate, a glass substrate, or a quartz substrate.

[0035] The corner portions of the base 31 have cutout side surfaces formed in a cylindrical curved surface shape (also called a castellation shape). However, the shape of the corner portions of the base 31 is not limited to this. The corner portions of the base may have cutout side surfaces formed in a prismatic shape, or may be substantially right-angled corner portions without cutouts.

[0036] The connection electrodes 33a and 33b are electrically connected to the quartz crystal vibrating element 10. The connection electrode 33a is electrically connected to the first connection electrode 16a of the quartz crystal vibrating element 10, and the connection electrode 33b is connected to the second connection electrode 16b of the quartz crystal vibrating element 10.

[0037] The lead electrode 34a electrically connects the connection electrode 33a to the external electrode 35a, and the lead electrode 34b electrically connects the connection electrode 33b to the external electrode 35b. The lead electrodes 34a and 34b are provided on the upper surface 31A of the base 31.

[0038] The external electrodes 35a and 35b are external terminals for electrically connecting the quartz crystal vibrating element 10 to an external substrate (not shown). The external electrode 35a electrically connects the first excitation electrode 14a of the quartz crystal vibrating element 10 to the external substrate, and the external electrode 35b electrically connects the second excitation electrode 14b of the quartz crystal vibrating element 10 to the external substrate. One of the external electrodes 35c and 35d is a ground electrode that grounds the lid member 40, and the other is a dummy electrode that is not electrically connected to the quartz crystal vibrating element 10 or the lid member 40. The external electrodes 35a, 35b, 35c, and 35d are each continuously provided from the cutout side surfaces provided at four corners of the base 31 to the bottom surface 31B. In the example shown in FIG. 1 , the external electrodes 35a and 35b are located at diagonal corners on the top surface 31A of the base 31, and the external electrodes 35c and 35d are located at another diagonal corner on the top surface 31A of the base 31.

[0039] The functions and positions of the external electrodes 35a, 35b, 35c, and 35d are not limited to those described above. Both external electrodes 35c and 35d may be ground electrodes, or both may be dummy electrodes. The external electrodes 35c and 35d may be omitted. The external electrode 35c may be electrically connected to one of the external electrodes 35a and 35b, and the external electrode 35d may be electrically connected to the other of the external electrodes 35a and 35b. In a plan view, the external electrodes 35a and 35b may be located on the same short side or the same long side of the upper surface 31A of the base 31.

[0040] Conductive holding members 36a and 36b are provided on the base member 30 on the side facing the quartz-crystal vibrating element 10. The conductive holding members 36a and 36b electrically connect the base member 30 and the quartz-crystal vibrating element 10 and mechanically hold the quartz-crystal vibrating element 10. The conductive holding member 36a electrically connects the first connection electrode 16a of the quartz-crystal vibrating element 10 to the connection electrode 33a of the base member 30. The conductive holding member 36b electrically connects the second connection electrode 16b of the quartz-crystal vibrating element 10 to the connection electrode 33b of the base member 30. The conductive holding members 36a and 36b are cured products of a conductive adhesive containing a thermosetting resin, a photocurable resin, or the like. The main component of the conductive holding members 36a and 36b is, for example, silicone resin. The conductive holding members 36a and 36b contain conductive particles, such as metal particles containing silver (Ag).

[0041] The main component of the conductive holding members 36a, 36b is not limited to silicone resin, but may be, for example, epoxy resin or acrylic resin. Furthermore, the conductive particles contained in the conductive holding members 36a, 36b are not limited to silver particles, but may be formed from other metals, conductive ceramics, conductive organic materials, etc. The conductive holding members 36a, 36b may also contain a conductive polymer.

[0042] The lid member 40 forms an internal space 39 between itself and the base member 30, in which the quartz-crystal vibrating element 10 is housed. The lid member 40 has a top wall 41 and a side wall 42 extending from the outer periphery of the top wall 41 toward the base member 30. The top wall 41 faces the base member 30 in the Y'-axis direction, sandwiching the quartz-crystal vibrating element 10 therebetween. The side wall 42 surrounds the quartz-crystal vibrating element 10 at a distance in the XZ'-plane direction. The lid member 40 is preferably made of a conductive material, more preferably a highly airtight metal material. By using a conductive material for the lid member 40, the lid member 40 can be endowed with an electromagnetic shielding function that reduces the transmission of electromagnetic waves into and out of the internal space 39. From the perspective of suppressing the generation of thermal stress, the lid member 40 is preferably made of a material with a thermal expansion coefficient similar to that of the base member 30, such as an Fe—Ni—Co alloy whose thermal expansion coefficient near room temperature matches that of glass or ceramic over a wide temperature range. The cover member 40 is electrically connected to at least one of the external electrodes 35c and 35d by a grounding member (not shown).

[0043] The material of the lid member is not limited to a conductive material. The lid member may be made of an insulating material such as ceramic. This prevents the electrodes across the joint provided on the main surface of the base member from being electrically short-circuited via the lid member, allowing the thickness of the joint to be reduced. When the lid member is made of ceramic, it is desirable to use the same material for the base body of the base member and the lid member in order to suppress the occurrence of thermal stress.

[0044] The joint 50 joins the base member 30 and the lid member 40 together and seals the internal space 39. The joint 50 is provided in a frame shape surrounding the quartz-crystal vibrating element 10 along the end (hereinafter referred to as the "tip") of the side wall 42 of the lid member 40 on the base member 30 side. The joint 50 is sandwiched between the tip of the side wall 42 of the lid member 40 and the upper surface 31A of the base member 30.

[0045] The bonding portion 50 includes an insulating film 52 and an organic adhesive 51 .

[0046] The insulating film 52 covers the tip of the sidewall 42 of the lid member 40. The organic adhesive 51 bonds the insulating film 52 to the base member 30. The insulating film 52 is made of an organic insulating material, such as an epoxy-based, vinyl-based, acrylic-based, urethane-based, or silicone-based resin. The organic adhesive 51 is, for example, an adhesive containing an epoxy-based, vinyl-based, acrylic-based, urethane-based, or silicone-based resin. The insulating film 52 increases the contact area with the bonding portion 50, thereby improving bonding strength. The insulating film 52 also reduces variations in the thickness of the organic adhesive 51 due to positional variations of the tip of the sidewall 42 caused by undulations in the lid member 40. In other words, because the flatness of the tip of the insulating film 52 is higher than the flatness of the tip of the sidewall 42, a decrease in bonding strength and a decrease in sealing performance due to variations in the thickness of the organic adhesive 51 are suppressed.

[0047] The organic adhesive 51 has an elastic modulus of, for example, 3 GPa or more and 7 GPa or less. The organic adhesive 51 may contain, for example, an insulating filler. The insulating filler is sandwiched between the base member 30 and the lid member 40 and functions as a spacer that ensures a certain distance between the base member 30 and the lid member 40. The material of the insulating filler is not particularly limited as long as it is an insulating material, and examples include resin, limestone, and clay. The resin insulating filler is, for example, spherical particles with a particle size of 3 μm or more and 100 μm or less.

[0048] Next, the dimensions of the bonding portion 50 according to the first embodiment will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is an enlarged cross-sectional view of the bonding portion of the crystal unit according to the first embodiment. Fig. 4 is a plan view of the crystal unit according to the first embodiment.

[0049] With respect to the joint 50, the direction intersecting the circumferential direction of the joint 50 along the upper surface 31A of the base 31 of the base member 30 is defined as the width direction, and the direction intersecting the upper surface 31A of the base 31 of the base member 30 is defined as the thickness direction. The upper surface 31A of the base 31 is an example of a main surface of the base member 30.

[0050] The volume of the internal space 39 of the quartz crystal resonator 1 is defined as the internal volume V. The internal volume V is the volume of the space surrounded by the substrate 31 of the base member 30 and the lid member 40, and includes the volumes of the quartz crystal resonator element 10, the conductive holding members 36a, 36b, etc. In order to reduce the effect of gas that has entered the internal space 39 on the quartz crystal resonator element 10, it is desirable to increase the internal volume V.

[0051] The widthwise dimension of the joint 50 is defined as the sealing width W. The sealing width W is the widthwise distance between the inner surface of the joint 50 facing the internal space 39 and the outer surface of the joint 50 facing away from the internal space 39. The sealing width W is specified, for example, as the average value of the sealing widths at multiple cross sections of the joint 50, but may also be specified as the sealing width at a cross section at a specific position. The sealing width of the joint 50 at a certain cross section is specified, for example, as the minimum or average value of the widthwise dimensions of the joint 50. The sealing width of the joint 50 at a certain cross section may also be specified as the widthwise dimension of a portion of the base member 30 that contacts the joint 50. The sealing width of the joint 50 at a certain cross section may also be specified as the widthwise dimension of a portion of the lid member 40 that contacts the joint 50. In this case, for example, the sealing width W is specified as the thickness of the lid member 40. In order to increase the difficulty of gas entering the internal space 39 from the outside through the joint 50 (hereinafter referred to as the "gas barrier properties of the joint 50"), it is desirable that the sealing width W be large.

[0052] The dimension of the joint 50 in the thickness direction is defined as the sealing thickness t. The sealing thickness t is the distance in the thickness direction between the joint surface of the base member 30 that contacts the joint 50 and the joint surface of the lid member 40 that contacts the joint 50. The sealing thickness t is specified, for example, as the average value of the sealing thicknesses at each of multiple cross sections of the joint 50, but may also be specified as the sealing thickness at a cross section at a specific position. The sealing thickness of the joint 50 at a certain cross section is specified, for example, as the maximum or average value of the dimension in the thickness direction of the portion of the joint 50 that is sandwiched between the base member 30 and the lid member 40. To improve the gas barrier properties of the joint 50, it is desirable that the sealing thickness t be small. To reduce the sealing thickness t, it is desirable that the flatness of the joint surface of the base member 30 that contacts the joint 50 be 3 μm or less, and it is desirable that the flatness of the joint surface of the tip of the side wall portion 42 of the lid member 40 that faces the base member 30 and contacts the joint 50 be 3 μm or less.

[0053] The dimension of the joint 50 in the circumferential direction is defined as the circumferential length Lc. The circumferential length Lc is the length of the outermost periphery of the outer surface of the joint 50 in a plan view. The circumferential length Lc is specified, for example, as the length of the outermost periphery of the lid member 40 in a plan view. The product of the sealing thickness t and the circumferential length Lc is defined as the sealing cross-sectional area S (S = t × Lc). To improve the gas barrier properties of the joint 50, it is desirable that the circumferential length Lc is small and that the sealing cross-sectional area S is small.

[0054] To summarize the internal volume V, sealing width W, and sealing cross-sectional area S, it is desirable that the parameter S / V / W be small in order to improve the gas barrier properties of the joint 50 and reduce the impact of gas that has entered the internal space 39. For example, in the quartz crystal resonator 1, the relationship S / V / W≦6 holds, and preferably the relationship S / V / W≦4 holds. Furthermore, from the perspective of processing accuracy, it is desirable that the relationship 1.5≦S / V / W holds. Note that "S / V / W" is a parameter obtained by dividing S by V and then further dividing the result by W, and can also be expressed as S / (V×W).

[0055] Next, the relationship between S / V / W and frequency fluctuation will be described with reference to FIG. 5 . FIG. 5 is a graph showing frequency fluctuations for examples and comparative examples based on the first embodiment. In the graph shown in FIG. 5 , the horizontal axis represents S / V / W. In the graph shown in FIG. 5 , the vertical axis represents the average value Δfavg of frequency fluctuations in a humid heat durability test of multiple quartz crystal vibrating elements in each example and comparative example based on the first embodiment. The durability test was conducted under the following conditions: test temperature 60°C, test humidity 93% RH, and test time 1000 hours. The frequency fluctuation Δf is the difference in frequency before and after the durability test. Note that in a humid heat environment, gas that has entered the internal space 39 of the quartz crystal vibrator 1 increases the internal pressure of the quartz crystal vibrator 1 and acts as a resistance to the vibration of the quartz crystal vibrating element 10, thereby decreasing the frequency. Furthermore, in a humid heat environment, water vapor and oxygen that have entered the internal space 39 of the quartz crystal vibrator 1 oxidize the electrodes of the quartz crystal vibrating element 10, increasing the mass of the quartz crystal vibrating element 10, thereby decreasing the frequency.

[0056] (Comparative Example) Planar dimensions of substrate 31 of base member 30: 1.65 mm x 1.25 mm Material of substrate 31 of base member 30: alumina Planar dimensions of lid member 40: 1.53 mm x 1.13 mm Material of lid member 40: Fe-Ni-Co alloy Material of organic adhesive 51: epoxy resin Elastic modulus of organic adhesive 51: 3 GPa Internal volume V of internal space 39: 0.17 mm ３ Sealing cross-sectional area S of joint 50: 0.12 mm ２ Sealing width W of joint 50: 0.10 mm S / V / W=7.1 Δfavg=−9.0 ppm

[0057] (First Example) Dimensions of substrate 31 of base member 30 in plan view: 1.65 mm x 1.25 mm Material of substrate 31 of base member 30: alumina Dimensions of lid member 40 in plan view: 1.53 mm x 1.13 mm Material of lid member 40: Fe-Ni-Co alloy Material of organic adhesive 51: epoxy resin Elastic modulus of organic adhesive 51: 3 GPa to 7 GPa Internal volume V of internal space 39: 0.21 mm ３ Sealing cross-sectional area S of joint 50: 0.07 mm ２Sealing width W of joint 50: 0.07 mm S / V / W = 4.8 Δfavg = -5.0 ppm In the first embodiment, spherical resin particles with a particle size of 10 μm are added to the organic adhesive 51, and the insulating film 52 is omitted.

[0058] Second Example Planar dimensions of substrate 31 of base member 30: 1.25 mm x 1.05 mm Material of substrate 31 of base member 30: alumina Planar dimensions of lid member 40: 1.24 mm x 1.04 mm Material of lid member 40: ceramic Material of organic adhesive 51: epoxy resin Elastic modulus of organic adhesive 51: 7 GPa Internal volume V of internal space 39: 0.45 mm ３ Sealing cross-sectional area S of joint 50: 0.18 mm ２ Sealing width W of joint 50: 0.11 mm S / V / W=3.6 Δfavg=−4.0 ppm

[0059] Third Example Dimensions of substrate 31 of base member 30 in plan view: 2.05 mm x 1.65 mm Material of substrate 31 of base member 30: alumina Dimensions of lid member 40 in plan view: 1.82 mm x 1.62 mm Material of lid member 40: Fe-Ni-Co alloy Material of organic adhesive 51: epoxy resin Elastic modulus of organic adhesive 51: 7 GPa Internal volume V of internal space 39: 0.2 mm ３ Sealing cross-sectional area S of joint 50: 0.04 mm ２ Sealing width W of joint 50: 0.14 mm S / V / W = 1.4 Δfavg = -3.0 ppm In the third embodiment, electrical connection between connection electrodes 33a, 33b and external electrodes 35a, 35b of base member 30 is achieved by through electrodes that penetrate substrate 31 in the thickness direction, and no extraction electrodes that overlap joint 50 are formed. This improves the flatness of the bonding surface joined by joint 50 of base member 30. The improved flatness of the bonding surface reduces sealing thickness t, which is the average thickness of joint 50, and reduces sealing cross-sectional area S, which is proportional to sealing thickness t.

[0060] The inventors discovered a correlation between the parameter S / V / W and the average value of frequency fluctuation, Δfavg, as shown in FIG. 5. As S / V / W decreases, Δfavg approaches 0, and as S / V / W increases, Δfavg decreases. Here, "Δfavg decreases" means that the absolute value of Δfavg, which is a negative value, increases. As S / V / W increases, the amount of change in Δfavg relative to the amount of change in S / V / W increases. The lower the gas barrier property of the joint 50, the smaller Δfavg becomes. A smaller Δfavg means greater frequency fluctuation in a humid and hot environment. From the graph shown in FIG. 5, it can be seen that the smaller the S / V / W, the smaller the frequency fluctuation in a humid and hot environment and the higher the humid and heat durability. For example, by satisfying the relationship S / V / W≦6.0, it is possible to achieve -7.0 ppm≦Δfavg. In other words, the frequency fluctuation after 1000 hours at 60°C and 93% RH can be suppressed to 7.0 ppm or less. Furthermore, by satisfying the relationship S / V / W≦4.0, it is possible to achieve −4.1 ppm≦Δfavg. In other words, the frequency fluctuation after 1000 hours at 60°C and 93% RH can be suppressed to 4.1 ppm or less.

[0061] Next, the relationship between S / V / W and equivalent series resistance (ESR) will be described with reference to FIG. 11 . FIG. 11 is a graph showing the ESR variation of the equivalent series resistance based on the first embodiment. In the graph shown in FIG. 11 , the horizontal axis represents S / V / W, and the vertical axis represents the variation rate ΔESR [%] of the equivalent series resistance in the moisture resistance test. The moisture resistance test was performed under the following conditions: test temperature 25°C, test humidity 60% RH, and test time 2000 hours. When the equivalent series resistance before the test is ESR_0 and the equivalent series resistance after the test is ESR_2000, ΔESR is calculated by the following formula: ΔESR={(ESR_2000-ESR_0) / ESR_0}×100. In other words, a positive ΔESR means that the ESR increased as a result of the moisture resistance test. If the moisture resistance of the quartz crystal resonator 1 is low, water vapor and oxygen that enter the internal space 39 of the quartz crystal resonator 1 will oxidize the electrodes of the quartz crystal resonator element 10, resulting in a large ΔESR. A smaller ESR is more advantageous for oscillation, so a small ΔESR is desirable.

[0062] The inventors have found that there is a correlation between the parameter S / V / W and the rate of change in equivalent series resistance, ΔESR, as shown in FIG. 11 . As shown in FIG. 11 , when S / V / W is approximately 6.0, ΔESR is approximately 3.7%, when S / V / W is approximately 2.9, ΔESR is approximately 1.6%, and when S / V / W is approximately 1.3, ΔESR is approximately -0.3. From this data, it was found that ΔESR exhibits a linear correlation with S / V / W, and, for example, when S / V / W is approximately 1.5, ΔESR is approximately 0. The smaller the S / V / W, the smaller the ΔESR. A smaller ΔESR means that the moisture resistance of the crystal unit 1 is high, and therefore, it can be shown that the smaller the S / V / W, the higher the moisture resistance of the crystal unit 1. For example, by satisfying the relationship S / V / W≦6.0, ΔESR can be reduced to 4% or less; by satisfying the relationship S / V / W≦5.0, ΔESR can be reduced to 3% or less; by satisfying the relationship S / V / W≦4.0, ΔESR can be reduced to 2% or less; and by satisfying the relationship S / V / W≦2.4, ΔESR can be reduced to 1% or less.

[0063] As described above, according to this embodiment, the quartz crystal resonator 1 includes the quartz crystal resonator element 10, the base member 30 on which the quartz crystal resonator element 10 is mounted, the lid member 40 that forms an internal space 39 between the base member 30 and the lid member 40 to accommodate the quartz crystal resonator element 10, and a bonding portion 50 that bonds the base member 30 and the lid member 40 to seal the internal space 39. The bonding portion 50 contains an organic adhesive 51, and the internal volume V of the internal space 39, the sealing width W of the bonding portion 50, and the sealing cross-sectional area S of the bonding portion 50 satisfy the relationship S / V / W≦6.

[0064] This makes it possible to suppress the frequency fluctuation of the crystal resonator 1 caused by gas entering the internal space 39 through the joint 50, and for example, the frequency fluctuation can be reduced to 7.0 ppm or less.

[0065] In one aspect of this embodiment, the relationship S / V / W≦4 holds.

[0066] This makes it possible to further suppress the frequency fluctuation of the crystal resonator 1, and for example, the frequency fluctuation can be reduced to 4.1 ppm or less.

[0067] In one aspect of this embodiment, the relationship 1.5≦S / V / W holds.

[0068] This makes it possible to prevent an increase in the difficulty of manufacturing the crystal resonator 1 due to the need for fine processing, and to prevent a decrease in the yield of the crystal resonator 1.

[0069] In one aspect of this embodiment, the modulus of elasticity of the organic adhesive 51 is 3 GPa or more and 7 GPa or less.

[0070] According to this, by setting the modulus of elasticity of the organic adhesive 51 to 3 GPa or more, it is possible to improve the gas barrier properties of the organic adhesive 51. By setting the modulus of elasticity of the organic adhesive 51 to 7 GPa or less, it is possible to improve the handleability and prevent the occurrence of defective products such as peeling of the bonded portion 50.

[0071] In one aspect of this embodiment, the organic adhesive 51 contains an insulating filler, and the insulating filler is sandwiched between the base member 30 and the cover member 40 .

[0072] According to this, the insulating filler ensures a gap between the base member 30 and the lid member 40, thereby suppressing short-circuiting of the electrodes on the base member 30 via the lid member 40. Therefore, when joining the lid member 40 to the base member 30, the lid member 40 can be brought close to the base member 30 without worrying about short-circuiting, and the sealing thickness t can be reduced.

[0073] In this embodiment, the base member 30 facing the quartz-crystal vibrating element 10 is flat, and the lid member 40 facing the quartz-crystal vibrating element 10 is concave, but the embodiment according to the present invention is not limited to this. For example, the base member facing the quartz-crystal vibrating element may be concave, and the lid member facing the quartz-crystal vibrating element may be flat. Furthermore, both the base member facing the quartz-crystal vibrating element and the lid member facing the quartz-crystal vibrating element may be concave.

[0074] Other embodiments will be described below. Note that components that are the same as or similar to those in the first embodiment are denoted by the same or similar reference numerals, and descriptions thereof will be omitted as appropriate. Furthermore, similar effects resulting from similar components will not be mentioned one after another.

[0075] Second Embodiment Next, the configuration of a quartz crystal resonator 2 according to a second embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a cross-sectional view of the quartz crystal resonator according to the second embodiment. Fig. 7 is an enlarged cross-sectional view of a bonding portion of the quartz crystal resonator according to the second embodiment.

[0076] The lid member 240 of the crystal unit 2 further includes a flange portion 43. The flange portion 43 extends from the tip of the sidewall portion 42 on the base member 30 side toward the opposite side of the internal space 39. The flange portion 43 is frame-shaped in plan view and is located on the lid member 40 closest to the base member 30. The joint portion 250 is sandwiched between the flange portion 43 and the base member 30. The width of the flange portion 43 is greater than the width of the tip of the sidewall portion 42, allowing for a larger sealing width W. Furthermore, providing the flange portion 43 increases the contact area between the lid member 240 and the joint portion 250, thereby improving adhesion between the lid member 240 and the joint portion 250. For this reason, as shown in FIGS. 6 and 7 , the insulating film 52 may be omitted from the joint portion 250.

[0077] Third Embodiment Next, the configuration of a quartz crystal resonator 3 according to a third embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a cross-sectional view of the quartz crystal resonator according to the third embodiment. Fig. 9 is an enlarged cross-sectional view of a bonding portion of the quartz crystal resonator according to the third embodiment.

[0078] The bonding portion 350 of the quartz crystal unit 3 includes an organic adhesive 51 and a protruding portion 53. The protruding portion 53 is provided on the surface of the base member 30 that is bonded to the lid member 240. The protruding portion 53 is made of an organic insulating material, such as an epoxy-based, vinyl-based, acrylic-based, urethane-based, or silicone-based resin. Since the protruding portion 53 functions as an insulating spacer, even when an attempt is made to reduce the sealing thickness t by bringing the lid member 240 closer to the base member 30, it is possible to prevent short-circuiting of the electrodes provided on the surface of the base member 30 via the lid member 240.

[0079] The flatness of the surface of the protrusion 53 facing the lid member 240 is higher than the flatness of the upper surface 31A of the substrate 31 of the base member 30. This makes it possible to suppress variations in the thickness of the organic adhesive 51 in the circumferential direction of the joint 350. For example, in the closest region where the gap between the flange 43 and the base member 30 is smallest, the approach between the flange 43 and the base member 30 is restricted, thereby suppressing an increase in the gap between the flange 43 and the base member 30 in regions other than the closest region. Therefore, it is possible to suppress an increase in the sealing thickness t, which is the average thickness of the joint 350.

[0080] The inner end of the convex portion 53 on the quartz-crystal vibrating element 10 side in the width direction is located closer to the quartz-crystal vibrating element 10 than the inner end of the flange portion 43 on the quartz-crystal vibrating element 10 side in the width direction. The center of the convex portion 53 in the width direction is located closer to the internal space 39 than the center of the bonding portion 350 in the width direction, and is located closer to the internal space 39 than the center of the flange portion 43 in the width direction. As shown in FIG. 8 , the distance Lti between the inner ends of the convex portions 53 on the quartz-crystal vibrating element 10 side in the width direction is smaller than the distance Lci between the inner ends of the flange portion 43 on the quartz-crystal vibrating element 10 side in the width direction. As shown in FIG. 9 , in a cross section along the width direction, the distance Hct in the width direction from the outermost end of the quartz-crystal vibrating element 1 to the center of the convex portion 53 is larger than the distance Hcc in the width direction from the outermost end of the quartz-crystal vibrating element 1 to the center of the flange portion 43. This allows the convex portions 53 to limit the wetting and spreading of the organic adhesive 51 toward the internal space 39, thereby reducing the surface area of ​​the organic adhesive 51 on the internal space 39 side. Therefore, it is possible to suppress frequency fluctuations caused by organic matter originating from the organic adhesive 51 adhering to the quartz crystal vibrating element 10 .

[0081] In this embodiment, the protrusions are provided on the base member side, but this is not limiting. The protrusions may be provided on the lid member side, or on both the base member side and the lid member side.

[0082] Fourth Embodiment Next, the configuration of a quartz crystal resonator 4 according to a fourth embodiment will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view of the quartz crystal resonator according to the fourth embodiment.

[0083] The base member 430 of the quartz crystal unit 4 is provided with a through electrode 37a that electrically connects the connection electrode 33a and the external electrode 35a. The through electrode 37a penetrates the base body 31 in the thickness direction. In the base member 430, the extraction electrode 34a is omitted, and instead the through electrode 37a is provided. Although not shown, the base member 430 is also provided with a through electrode 37b that electrically connects the connection electrode 33b and the external electrode 35b. This makes it possible to omit the extraction electrode that crosses the joint 250, thereby increasing the flatness of the joint surface of the base member 430.

[0084] Some or all of the embodiments of the present invention will be described below, but the present invention is not limited to the following descriptions.

[0085] <1> A piezoelectric vibrator comprising: a piezoelectric vibration element having a piezoelectric piece and an excitation electrode configured to be able to apply a voltage to the piezoelectric piece; a base member on which the piezoelectric vibration element is mounted; a lid member that houses the piezoelectric vibration element in an internal space provided between the base member and the lid member; and a joint that joins the base member and the lid member and seals the internal space, wherein the joint includes an organic adhesive, and when a direction along a main surface of the base member that intersects with the circumferential direction of the joint is defined as a width direction and a direction that intersects with the main surface of the base member is defined as a thickness direction, the volume of the internal space is defined as an internal volume V, the dimension of the joint in the width direction is defined as a sealing width W, the dimension of the joint in the thickness direction is defined as a sealing thickness t, the dimension of the joint in the circumferential direction is defined as a circumferential length Lc, and the product of the sealing thickness t and the circumferential length Lc is defined as a sealing cross-sectional area S, the relationship S / V / W≦6 holds.

[0086] <2> The piezoelectric vibrator according to <1>, wherein a relationship of S / V / W≦4 is satisfied.

[0087] <3> The piezoelectric vibrator according to <1> or <2>, wherein the relationship 1.5≦S / V / W holds.

[0088] <4> The piezoelectric vibrator according to any one of <1> to <3>, wherein the organic adhesive has a modulus of elasticity of 3 GPa or more and 7 GPa or less.

[0089] <5> The piezoelectric vibrator according to any one of <1> to <4>, wherein the organic adhesive is an adhesive containing an epoxy resin.

[0090] <6> The piezoelectric vibrator according to any one of <1> to <5>, wherein the organic adhesive contains an insulating filler, and the insulating filler is sandwiched between the base member and the lid member.

[0091] <7> The piezoelectric vibrator according to any one of <1> to <6>, wherein a convex portion is provided on at least one of a bonding surface of the base member that is bonded to the lid member and a bonding surface of the lid member that is bonded to the base member.

[0092] <8> The piezoelectric vibrator according to <7>, wherein the center of the protrusion in the width direction is located closer to the internal space than the center of the joint in the width direction.

[0093] <9> The piezoelectric vibrator according to <7> or <8>, wherein the material of the protrusions is an insulating material.

[0094] <10> The piezoelectric vibrator according to any one of <1> to <9>, wherein at least one of the piezoelectric vibrating element side of the lid member and the piezoelectric vibrating element side of the base member is provided with a concave shape.

[0095] <11> The piezoelectric vibrator according to <10>, wherein the lid member has a top wall portion facing the base member across the piezoelectric vibrating element, a side wall portion extending from an outer edge of the top wall portion toward the lid member, and a flange portion extending from an end of the side wall portion on the base member side to the opposite side to the internal space.

[0096] <12> The piezoelectric vibrator according to any one of <1> to <11>, wherein the cover member is made of ceramic.

[0097] <13> The piezoelectric vibrator according to any one of <1> to <12>, wherein the base member has: an insulating plate-shaped substrate; a connection electrode provided on the piezoelectric vibration element side of the substrate and electrically connected to the piezoelectric vibration element; an external electrode provided on the substrate on the opposite side to the piezoelectric vibration element; and a through electrode provided through the substrate and electrically connecting the connection electrode and the external electrode.

[0098] <14> The piezoelectric vibrator according to any one of <1> to <12>, wherein the piezoelectric vibrating element is a quartz crystal vibrating element.

[0099] In this specification, a quartz crystal resonator having a quartz crystal element as a piezoelectric element has been described as an example, but the piezoelectric resonator is not limited to this. Examples of piezoelectric elements suitable for use in the piezoelectric vibrator according to this embodiment include piezoelectric ceramics such as lead zirconate titanate (PZT) and aluminum nitride, and piezoelectric single crystals such as lithium niobate and lithium tantalate, but the present invention is not limited to these and can be selected as appropriate.

[0100] The embodiments according to the present invention are not particularly limited and can be appropriately applied to any device that performs electromechanical energy conversion using the piezoelectric effect, such as a timing device, a sound generator, an oscillator, or a load sensor.

[0101] As described above, according to one aspect of the present invention, it is possible to provide a piezoelectric vibrator capable of suppressing frequency fluctuations.

[0102] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. The present invention may be modified or improved without departing from its spirit, and equivalents are also included within the scope of the present invention. In other words, designs modified by those skilled in the art as appropriate to the embodiments and / or modifications are also encompassed within the scope of the present invention as long as they incorporate the characteristics of the present invention. For example, the elements and their arrangements, materials, conditions, shapes, sizes, etc. of the embodiments and / or modifications are not limited to those illustrated and can be modified as appropriate. Furthermore, the embodiments and modifications are merely examples, and it goes without saying that partial substitutions or combinations of the components shown in different embodiments and / or modifications are possible. These are also encompassed within the scope of the present invention as long as they incorporate the characteristics of the present invention.

[0103] 1...Crystal resonator 10...Crystal vibrating element 30...Base member 31...Substrate 31A...Top surface 31B...Bottom surface 39...Inner space 40...Lid member 41...Top wall portion 42...Side wall portion 43...Flange portion 50...Joint portion 51...Organic adhesive 52...Insulating film 11...Crystal piece 11A...Top surface 11B...Bottom surface 14a...First excitation electrode 14b...Second excitation electrode 15a...First extraction electrode 15b...Second extraction electrode 16a...First connection electrode 16b...Second connection electrode V...Inner volume W...Sealing width t...Sealing thickness Lc...Perimeter length S...Sealing cross-sectional area

Claims

1. A piezoelectric vibrator comprising: a piezoelectric vibration element having a piezoelectric piece and an excitation electrode configured to be able to apply a voltage to the piezoelectric piece; a base member on which the piezoelectric vibration element is mounted; a lid member that houses the piezoelectric vibration element in an internal space provided between the base member and the lid member; and a joint that joins the base member and the lid member and seals the internal space, wherein the joint includes an organic adhesive, and when a direction along the main surface of the base member that intersects with the circumferential direction of the joint is defined as the width direction, and a direction that intersects with the main surface of the base member is defined as the thickness direction, the volume of the internal space is defined as the internal volume V, the dimension of the joint in the width direction is defined as the sealing width W, the dimension of the joint in the thickness direction is defined as the sealing thickness t, the dimension of the joint in the circumferential direction is defined as the circumferential length Lc, and the product of the sealing thickness t and the circumferential length Lc is defined as the sealing cross-sectional area S, the relationship S / V / W≦6 holds.

2. The piezoelectric vibrator according to claim 1, wherein the relationship S / V / W≦4 holds.

3. The piezoelectric vibrator according to claim 1 or 2, wherein the relationship 1.5≦S / V / W holds.

4. The piezoelectric vibrator according to any one of claims 1 to 3, wherein the organic adhesive has a modulus of elasticity of 3 GPa or more and 7 GPa or less.

5. The piezoelectric vibrator according to any one of claims 1 to 4, wherein the organic adhesive is an adhesive containing an epoxy resin.

6. A piezoelectric vibrator according to any one of claims 1 to 5, wherein the organic adhesive contains an insulating filler, and the insulating filler is sandwiched between the base member and the lid member.

7. A piezoelectric vibrator according to any one of claims 1 to 6, wherein a convex portion is provided on at least one of the bonding surface of the base member that is bonded to the lid member and the bonding surface of the lid member that is bonded to the base member.

8. The piezoelectric vibrator according to claim 7, wherein the center of the convex portion in the width direction is located closer to the internal space than the center of the joint portion in the width direction.

9. The piezoelectric vibrator according to claim 7 or 8, wherein the material of the protrusions is an insulating material.

10. A piezoelectric vibrator according to any one of claims 1 to 9, wherein at least one of the piezoelectric vibrator element side of the cover member and the piezoelectric vibrator element side of the base member is concave.

11. A piezoelectric vibrator as described in claim 10, wherein the lid member has a top wall portion facing the base member across the piezoelectric vibrating element, a side wall portion extending from the outer edge of the top wall portion toward the lid member, and a flange portion extending from the end of the side wall portion facing the base member to the side opposite the internal space.

12. The piezoelectric vibrator according to any one of claims 1 to 11, wherein the material of the cover member is ceramic.

13. A piezoelectric vibrator as described in any one of claims 1 to 12, wherein the base member has an insulating plate-shaped substrate, a connection electrode provided on the piezoelectric vibration element side of the substrate and electrically connected to the piezoelectric vibration element, an external electrode provided on the side of the substrate opposite the piezoelectric vibration element, and a through electrode provided through the substrate and electrically connecting the connection electrode and the external electrode.

14. The piezoelectric vibrator according to any one of claims 1 to 13, wherein the piezoelectric vibrating element is a quartz crystal vibrating element.

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