Substrate and piezoelectric vibrator
The substrate design with a bonding region, metal film, and low-permeability insulating film addresses gas intrusion and leakage issues in piezoelectric vibration components, improving airtightness and aging performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MURATA MFG CO LTD
- Filing Date
- 2025-09-10
- Publication Date
- 2026-06-11
Smart Images
Figure JP2025031954_11062026_PF_FP_ABST
Abstract
Description
Substrate and piezoelectric vibrator 【0001】 The present invention relates to a substrate and a piezoelectric vibrator. 【0002】 In various electronic devices such as mobile communication terminals, communication base stations, and home appliances, piezoelectric vibration elements are used for applications such as timing devices, sensors, or oscillators. The piezoelectric vibration element includes a piezoelectric piece having a pair of main surfaces, and a pair of excitation electrodes provided on the pair of main surfaces of the piezoelectric piece. 【0003】 For example, Patent Document 1 discloses a piezoelectric vibration component including a substrate, a piezoelectric vibrator held on the substrate, a cap fixed to the substrate with an adhesive, and a lead electrode formed on the upper surface of the substrate so that one end is connected to a terminal electrode. 【0004】 Japanese Patent No. 4947213 【0005】 However, in the piezoelectric vibration component of Cited Document 1, in the adhesion region between the cap and the substrate, the electrode portion led out to the terminal electrode is convex and higher than the substrate surface. Therefore, a void corresponding to that portion is formed in the adhesion layer between the bottom surface of the cap and the substrate in the portion without the lead electrode, and the thickness of the resin sealing portion increases. As a result, there are problems such as deterioration of the aging performance due to easy intrusion of gas from the resin sealing portion and deterioration of the leakage failure rate due to the increase in the thickness of the sealing adhesive. 【0006】 The present invention has been made in view of such circumstances, and an object thereof is to improve airtightness. 【0007】A substrate according to one aspect of the present invention comprises a base member having a main surface for mounting a piezoelectric vibration element; a bonding region formed in a frame shape along the outer periphery of the main surface, which is bonded to a bonding portion that seals the piezoelectric vibration element; a metal film formed on the main surface, which includes an electrode pad disposed inside the bonding region and holding the piezoelectric vibration element, and a lead electrode drawn out from the electrode pad to an external electrode, intersecting the bonding region; and an insulating film formed on the main surface in a region including the bonding region, wherein the bonding portion is made of an organic adhesive, and the insulating film is made of an insulating material with lower gas permeability than the organic adhesive, and is formed in the bonding region while avoiding the surface of the lead electrode. 【0008】 According to the present invention, it is possible to improve airtightness. 【0009】 Figure 1 is an exploded perspective view schematically showing the configuration of the quartz crystal oscillator in this embodiment. Figure 2 is a plan view schematically showing an example of the configuration of the substrate in this embodiment. Figure 3 is a plan view schematically showing the configuration of the cross section of the quartz crystal oscillator shown in Figure 1 along the line III-III. Figure 4 is a plan view schematically showing the configuration of the cross section of the quartz crystal oscillator shown in Figure 1 along the line IV-IV. Figure 5 is a perspective view schematically showing another example of the configuration of the substrate in this embodiment. Figure 6 is a perspective view schematically showing an example of the configuration of the lid in this embodiment. Figure 7 is a plan view schematically showing a part of the cross section of another example of the configuration of the lid in this embodiment along the line III-III. 【0010】 Embodiments of the present invention are described below. In the following drawings, identical or similar components are denoted by identical 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 limited to these embodiments. 【0011】Each drawing may, for convenience, include a Cartesian coordinate system consisting of the X, Y', and Z' axes to clarify the relationships between the drawings and to help understand the positional relationships of each component. The X, Y', and Z' axes correspond to each other in each drawing. The X, Y', and Z' axes correspond to the crystal axes of the quartz piece 11, which will be described later. The X axis corresponds to the electrical axis (polarity axis) of the quartz, the Y axis to the mechanical axis of the quartz, and the Z axis to the optical axis of the quartz. The Y' and Z' axes are axes obtained by rotating the Y and Z axes by θ degrees around the X axis in the direction from the Y axis to the Z axis, respectively. 【0012】 In the following explanation, the direction parallel to the X-axis is referred to as the "X-axis direction," the direction parallel to the Y'-axis as the "Y'-axis direction," and the direction parallel to the Z'-axis as the "Z'-axis direction." Furthermore, the direction of the arrowheads for the X-axis, Y'-axis, and Z'-axis is referred to as "positive" or "+ (plus)," and the direction opposite to the arrow is referred to as "negative" or "- (minus)." For convenience, the +Y'-axis direction will be described as upward and the -Y'-axis direction as downward, but the vertical orientation of the quartz oscillator 10 and the quartz resonator 1 is not limited. Also, the plane specified by the X-axis and Z'-axis will be referred to as the Z'X plane, and the same applies to the planes specified by the other axes. 【0013】 The configuration of the quartz crystal oscillator according to this embodiment will be described with reference to Figures 1 to 4. Figure 1 is an exploded perspective view schematically showing the configuration of the quartz crystal oscillator 1 in this embodiment. Figure 2 is a plan view schematically showing an example of the configuration of the base member 31 in this embodiment. Figure 3 is a plan view schematically showing the configuration of a cross-section of the quartz crystal oscillator shown in Figure 1 along the line III-III. Figure 4 is a plan view schematically showing the configuration of a cross-section of the quartz crystal oscillator shown in Figure 1 along the line IV-IV. 【0014】 As shown in Figure 1, the quartz oscillator 1 comprises a quartz oscillator element 10, a substrate 30, a cover portion 40, and a joint portion 50. In the following description, the X-axis direction is also referred to as the "length direction" of the quartz oscillator 1 and the substrate 30, the Z'-axis direction is also referred to as the "width direction" of the quartz oscillator 1 and the substrate 30, and the Y'-axis direction is also referred to as the "thickness direction" of the quartz oscillator 1 and the substrate 30. 【0015】The crystal oscillator 1 has external dimensions smaller than, for example, 2.0 × 1.6 mm (2016 size), and is a small crystal oscillator such as 1.6 × 1.2 mm (1612 size) or 1.0 × 0.8 mm (1008 size). The crystal oscillator 1 is used as a component in, 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 oscillator 10 is an element that vibrates a quartz crystal by the piezoelectric effect and converts electrical energy into mechanical energy. The quartz crystal oscillator 10 includes a thin, flake-shaped quartz crystal (Quartz Crystal Element). 【0017】 The quartz piece 11 has a first main surface 11A and a second main surface 11B that are opposite to each other. The quartz piece 11 has a flat plate shape. Therefore, the first main surface 11A and the second main surface 11B of the quartz piece 11 are both flat surfaces. Note that the quartz piece 11 is not limited to a flat plate shape; for example, the central part may be convex or concave. 【0018】 The quartz piece 11 is, for example, an AT-cut type quartz crystal. An AT-cut type quartz crystal is formed such that the XZ' plane is the main plane and the direction parallel to the Y' axis is the thickness. As an example, when the first main plane 11A is viewed from above in the thickness direction (hereinafter simply referred to as "planar view"), the shape of the quartz piece 11 (hereinafter referred to as "planar shape") is rectangular, having a pair of short sides extending in the Z' axis direction and a pair of long sides extending in the X axis direction. 【0019】Furthermore, the planar shape of the quartz piece 11 is not limited to the shape described above. For example, the planar shape of the quartz piece may be rectangular with a long side extending in the Z' direction and a short side extending in the X direction, or it may be square with a side extending in the Z' direction and a side extending in the X direction. Also, the planar shape of the quartz piece may be rectangular with sides extending along the Z direction and the direction intersecting the Z' direction. Moreover, the planar shape of the quartz piece may be polygonal, circular, elliptical, or a combination thereof. 【0020】 The AT-cut quartz piece 11 is cut out using the XZ' plane, which is determined by rotating the Y and Z axes, respectively, around the X axis in the direction from the Y axis to the Z axis by 35 degrees 15 minutes ± 1 minute 30 seconds, as the main plane of the XZ' plane, which is determined by the X and Z' axes. 【0021】 Furthermore, the rotation angles of the Y' and Z' axes in the AT-cut quartz piece 11 may be tilted within the range of 35 degrees 15 minutes to -5 degrees or more and +15 degrees or less. In addition, the cut angle of the quartz piece 11 may be a different cut other than the AT cut, such as a BT cut, GT cut, SC cut, etc. 【0022】 Quartz oscillators using AT-cut quartz crystals exhibit high frequency stability over a wide temperature range. Furthermore, AT-cut quartz oscillators have excellent aging characteristics and can be manufactured at low cost. Additionally, AT-cut quartz oscillators utilize the thickness-shear vibration mode as their primary vibration mode. 【0023】 The quartz oscillator 10 further includes a pair of excitation electrodes. An alternating electric field is applied between this pair of excitation electrodes. As a result, the vibrating portion of the quartz piece 11 vibrates at a predetermined oscillation frequency by the thickness-slip vibration mode, and resonance characteristics associated with this vibration are obtained. 【0024】Thus, because the main vibration of the quartz oscillator 10 is a thickness-slip vibration mode, a quartz oscillator 1 that performs thickness-slip vibration at MHz vibration frequencies can be easily realized by using, for example, an AT-cut quartz piece 11. 【0025】 Furthermore, the primary vibration of the quartz crystal oscillator is not limited to the thickness-slip vibration mode, but may also be, for example, the thickness-longitudinal vibration mode, the spreading vibration mode, the length vibration mode, or the bending vibration mode. 【0026】 The quartz oscillator 10 includes a first excitation electrode 14a and a second excitation electrode 14b, which constitute a pair of electrodes. The first excitation electrode 14a is provided on the first main surface 11A. The second excitation electrode 14b is provided on the second main surface 11B. The first excitation electrode 14a and the second excitation electrode 14b are provided facing each other, sandwiching the quartz piece 11 in a region that includes the center of each main surface. The first excitation electrode 14a and the second excitation electrode 14b are arranged so that their entirety substantially overlaps in the XZ' plane. The region where the first excitation electrode 14a and the second excitation electrode 14b are provided becomes the vibrating part of the quartz piece 11. 【0027】 The first excitation electrode 14a and the second excitation electrode 14b each have a long side parallel to the X-axis direction, a short side parallel to the Z'-axis direction, and a thickness parallel to the Y'-axis direction. In the example shown in Figure 1, in the XZ' plane, the long sides of the first excitation electrode 14a and the second excitation electrode 14b are parallel to the long side of the quartz crystal 11. Similarly, the short sides of the first excitation electrode 14a and the second excitation electrode 14b are parallel to the short side of the quartz crystal 11. Furthermore, the long sides of the first excitation electrode 14a and the second excitation electrode 14b are separated from the long side of the quartz crystal 11. Similarly, the short sides of the first excitation electrode 14a and the second excitation electrode 14b are separated from the short side of the quartz crystal 11. 【0028】 The first excitation electrode 14a has a rectangular shape with a short side extending in the Z' axis direction and a long side extending in the X axis direction. The first excitation electrode 14a also has thickness in the Y' axis direction. The second excitation electrode 14b has a similar shape. 【0029】The planar shapes of the first and second excitation electrodes are not limited to the examples described above. The planar shapes of the first and second excitation electrodes may be rectangular with a short side extending in the X-axis direction, or square with sides extending in the X-axis direction and sides extending in the Z'-axis direction. The planar shapes of the first and second excitation electrodes may be rectangular with sides extending along directions intersecting the Z-axis direction and the Z'-axis direction. The planar shapes of the first and second excitation electrodes may be polygonal, circular, elliptical, or a combination thereof. 【0030】 The quartz oscillator 10 further includes a first extraction electrode 15a and a second extraction electrode 15b, and a first connecting electrode 16a and a second connecting electrode 16b. The first connecting electrode 16a is electrically connected to the first excitation electrode 14a via the first extraction electrode 15a. The second connecting electrode 16b is electrically connected to the second excitation electrode 14b via the second extraction electrode 15b. The first connecting electrode 16a and the second connecting electrode 16b are terminals for electrically connecting to the substrate 30. The first connecting electrode 16a and the second connecting electrode 16b are each provided on the second main surface 11B of the quartz piece 11. The first connecting electrode 16a and the second connecting electrode 16b are each arranged along the direction of the short side near the short side on the negative Z' axis side of the quartz piece 11. 【0031】The first extraction electrode 15a electrically connects the first excitation electrode 14a and the first connecting electrode 16a. Specifically, the first extraction electrode 15a extends from the first excitation electrode 14a on the first main surface 11A in the positive Z' direction and the negative X direction, and extends from the first main surface 11A through each side surface of the quartz piece 11 to the second main surface 11B, and is electrically connected to the first connecting electrode 16a on the second main surface 11B. The second extraction electrode 15b electrically connects the second excitation electrode 14b and the second connecting electrode 16b. Specifically, the second extraction electrode 15b extends from the second excitation electrode 14b on the second main surface 11B in the negative X direction, and is electrically connected to the second connecting electrode 16b on the second main surface 11B. In this way, by extending the first extraction electrode 15a and the second extraction electrode 15b, the first connecting electrode 16a and the second connecting electrode 16b, which are electrically connected to the first excitation electrode 14a and the second excitation electrode 14b provided on both main surfaces of the first main surface 11A and the second main surface 11B, can be positioned on one of the second main surfaces 11B. 【0032】 The first connecting electrode 16a and the second connecting electrode 16b are electrically connected to electrodes on the substrate 30, which will be described later, via conductive holding members 36a and 36b. 【0033】 The first excitation electrode 14a, the first extraction electrode 15a, and the first connecting electrode 16a are provided integrally. Similarly, the second excitation electrode 14b, the second extraction electrode 15b, and the second connecting electrode 16b are also provided integrally. The group of electrodes consisting of the first excitation electrode 14a, the first extraction electrode 15a, and the first connecting electrode 16a is designated as the first electrode, and the group of electrodes consisting of the second excitation electrode 14b, the second extraction electrode 15b, and the second connecting electrode 16b is designated as the second electrode. 【0034】The first and second electrodes have a multilayer structure, for example, formed by stacking a base layer and a surface layer in that order. The base layer material is a metallic material that has better adhesion to the quartz piece 11 than the surface layer material. Examples of base layer materials include chromium (Cr), titanium-tungsten alloy (WTi), or alloys containing these. The surface layer material is preferably a metallic material that is less prone to oxidation than the base layer material and has better conductivity than the base layer material. Examples of surface layer materials include gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), or alloys containing these. The first and second electrodes may also contain titanium (Ti), aluminum (Al), molybdenum (Mo), or aluminum-copper alloy (AlCu) with aluminum (Al) as the main component. 【0035】 In this embodiment, the quartz oscillator 10 is described as having a configuration including a flat plate-shaped quartz piece 11, but it is not limited thereto. The quartz piece may employ a mesa-type structure in which the vibrating portion including the center of the main surface is thicker than the peripheral portion, or an inverse mesa structure in which the vibrating portion is thinner than the peripheral portion. Alternatively, the quartz piece may have a convex or bevel shape in which the change in thickness (e.g., a step) between the vibrating portion and the peripheral portion changes continuously. Furthermore, the cut angle of the quartz piece may be a different cut other than the AT cut, such as a BT cut. Moreover, the quartz oscillator may be a tuning fork-type quartz oscillator, which uses a quartz plate cut at a predetermined angle with respect to the X, Y, and Z axes that are mutually orthogonal as the crystal axes of the quartz as a base material, and comprises a quartz piece having a base portion and at least one vibrating arm extending from the base portion, and an excitation electrode provided on the vibrating arm to cause bending vibration. 【0036】 Thus, by including a pair of first excitation electrodes 14a and second excitation electrodes 14b provided on both main surfaces of the quartz crystal piece 11, the quartz crystal oscillator 10 can be easily constructed (realized) in which the vibrating part vibrates in a predetermined vibration mode. 【0037】 The lid portion 40 forms an internal space 39 between itself and the substrate 30, in which the quartz crystal oscillator 10 is housed. 【0038】The lid portion 40 has a concave shape, specifically a box shape including an opening. The lid portion 40 has a top wall portion 41, a side wall portion 42 connected to the outer edge of the top wall portion 41 and extending in the direction normal to the main surface of the top wall portion 41, and a lower edge portion 43 which is the end of the side wall portion 42 opposite to the connection end with the top wall portion 41. The top wall portion 41 faces the substrate 30 with the crystal oscillator 10 in between in the Y' axis direction. The side wall portions 42 surround the crystal oscillator 10 with a gap in the XZ' plane direction. The lower edge portion 43 is provided in a frame shape in plan view and is provided closest to the substrate 30 of the lid portion 40. The lid portion 40 is electrically connected to at least one of the external electrodes 35c and 35d, which will be described later, by a grounding member (not shown). In this embodiment, the shape of the lower edge portion is not limited to the shape disclosed in Figure 3, and for example, the lower edge portion 43 may have a flange extending outward. 【0039】 Alternatively, instead of the lid portion 40, a lid portion 40A as shown in Figure 6 may be provided. The lid portion 40A has a protrusion 43A that projects toward the base member 31 at the lower edge portion 43 corresponding to the portion where the lead electrodes 34a and 34b are provided, i.e., the portion where the insulating film 32 is not formed. In the example shown in Figure 6, the protrusions 43A are provided at the four corner portions of the lid portion 40A, but the portion where the protrusions 43A are provided is not limited to this, and it is sufficient to have the protrusions 43A in the portion where the lead electrodes 34a and 34b are provided, i.e., the portion where the insulating film 32 is not formed. The protrusions 43A may be located on the same short side or on the same long side in a plan view of the lower edge portion 43. 【0040】 The lid portion 40A has a protrusion 43A on its lower edge portion 43, which corresponds to the portion where the insulating film 32 is not provided. When the lid portion 40 is joined to the substrate 30, the protrusion 43A fits into the recessed structure of the substrate 30. As a result, the thickness of the joining portion 50 can be reduced in the portion with the protrusion 43A. Furthermore, when mounting the lid portion 40A to the substrate 30, the recessed structure of the substrate 30 and the protrusion 43A make alignment easier. 【0041】The material of the lid 40 is preferably a conductive material, and more preferably a highly airtight metallic material. By making the lid 40 out of a conductive material, an electromagnetic shielding function that reduces the inflow and outflow of electromagnetic waves into the internal space 39 can be provided to the lid 40. From the viewpoint of suppressing the generation of thermal stress, it is desirable that the material of the lid 40 is a material that has a coefficient of thermal expansion close to that of the substrate 30. For example, an Fe-Ni-Co alloy whose coefficient of thermal expansion at or near room temperature matches that of glass or ceramic over a wide temperature range. Specifically, the lid 40 is made of 42 alloy, which is an alloy containing iron (Fe) and nickel (Ni), or Kovar, which is an alloy containing iron (Fe), nickel (Ni), and cobalt (Co). Both 42 alloy and Kovar are known as metals with low coefficients of thermal expansion. A nickel (Ni) layer formed by plating may be provided on the innermost surface of the lid 40. In addition, a gold (Au) layer or the like may be provided on the outermost surface of the lid 40 for the purpose of preventing oxidation, etc. Furthermore, a nickel (Ni) layer and a gold (Au) layer formed by plating may be provided on the surface of the lower edge 43 facing the substrate 30 (hereinafter also referred to as the "bottom surface"). 【0042】 The material of the lid portion 40 is not limited to a conductive material. The material of the lid portion 40 may be an insulating material such as ceramic. In this case, the electrodes that cross the joint portion 50 provided on the first main surface 31A of the substrate 30 will not be electrically short-circuited through the lid portion 40, and therefore the thickness of the joint portion 50 can be reduced. When the lid portion 40 is made of ceramic, it is desirable to use the same material for the base member 31 of the substrate 30 and the lid portion 40 from the viewpoint of suppressing the generation of thermal stress. 【0043】 The external dimensions of the lid portion 40 are, for example, 1.53 x 1.13 mm when the external dimensions of the crystal oscillator 1 are 1.6 x 1.2 mm (size 1612). 【0044】The joint portion 50 joins the lid portion 40 and the substrate 30. The joint portion 50 has a frame shape and is provided on the outer peripheral portion of the first main surface 31A of the substrate 30 along the entire circumference of the lower edge portion 43 of the lid portion 40. That is, the joint portion 50 is sandwiched between the bottom surface of the lower edge portion 43 of the lid portion 40 and the first main surface 31A of the substrate 30. Thereby, the crystal oscillator 10 is sealed in the internal space 39 surrounded by the lid portion 40 and the substrate 30. 【0045】 The joint portion 50 may include a cap insulating film 44 that covers the bottom surface of the lower edge portion 43 of the lid portion 40 between the joint portion 50 and the lid portion 40 (see FIG. 7). In this case, the material of the cap insulating film is preferably one with high adhesion to metal or one that is easily leveled to the shape of the lower edge portion. For example, an insulating member containing a resin such as an epoxy-based, phenol-based, or polyimide-based resin may be used. According to the cap insulating film 44, the contact area between the joint portion 50 and the lid portion 40 can be increased to improve the joint strength, and the insulation reliability between the lid portion 40 and the substrate 30 can be improved. 【0046】 Also, in the embodiment disclosed in FIG. 3, the bottom surface of the lower edge portion 43 of the lid portion 40 is a straight line, but the shape of the bottom surface is not limited to this. For example, the bottom surface of the lower edge portion 43 may have a curved surface as shown in FIG. 7. In the cross-section obtained by cutting the lower edge portion 43 in the normal direction of the side wall portion 42, it may be rounded so as to protrude in the direction of the joint portion with the substrate 30. 【0047】In this case, it is desirable that the apex of the roundness is at the center in the width direction of the bonding region 50A to be described later, that is, at the center of the width of the bottom surface in the cross section. When the apex of the roundness is at the center in the width direction of the bonding region 50A, when the lid portion 40 is bonded to the substrate 30, the organic adhesive of the bonding portion 50 is evenly spread over both widths. As a result, the bonding portion 50 has a fillet shape at the boundary between the lid portion 40 and the substrate 30, and it becomes possible to widen the sealing width, contributing to an improvement in adhesion stability. Further, when the lower edge portion 43 has the cap insulating film 44, as shown in FIG. 7, the cap insulating film 44 also adheres to the lid portion 40 in a curved surface shape due to surface tension or the like. When the bottom surface of the lower edge portion 43 is formed in a curved surface shape, the surface area of the lower edge portion 43 becomes smaller than that of a structure in which the bottom surface of the lower edge portion 43 is a straight line. Therefore, the contact area between the lower edge portion 43 and the cap insulating film 44 becomes smaller, and the coating film thickness of the cap insulating film 44 can be reduced. 【0048】 The bonding portion 50 includes an organic adhesive that bonds the lower edge portion 43 of the lid portion 40 and the substrate 30. The organic adhesive is, for example, an adhesive containing a resin such as an epoxy-based, vinyl-based, acrylic-based, urethane-based or silicone-based resin. 【0049】 Thus, since the organic adhesive contained in the bonding portion 50 is an adhesive containing an epoxy-based resin, the lid portion 40 and the substrate 30 can be easily bonded. 【0050】 The substrate 30 supports the crystal vibration element 10 so as to be vibratable. Specifically, the crystal vibration element 10 is held on the substrate 30 via conductive holding members 36a and 36b so as to be vibratable. 【0051】 The substrate 30 includes a base member 31. The base member 31 has a flat plate shape and has a first main surface 31A and a second main surface 31B which are XZ' planes facing each other. The first main surface 31A and the second main surface 31B correspond to a set of main surfaces of the base member 31. The first main surface 31A is located on the side facing the crystal vibration element 10 and the lid portion 40, and corresponds to a mounting surface on which the crystal vibration element 10 is provided and mounted. 【0052】The base member 31 is a substrate mainly composed of ceramic, for example, a sintered material of an insulating ceramic such as alumina (Al2O3). In this case, the base member 31 may be formed by laminating and sintering a plurality of insulating ceramic sheets. 【0053】 The corners of the base member 31 have notched sides formed in a cylindrical curved shape (also called a "castellation shape"). However, the shape of the corners of the base member 31 is not limited to this. For example, the corners of the base member may have notched sides formed in a prismatic shape, or they may be approximately right-angle corners without notches. 【0054】 The external dimensions of the substrate 30 are, for example, 1.65 x 1.25 mm when the external dimensions of the crystal oscillator 1 are 1.6 x 1.2 mm (1612 size). 【0055】 The substrate 30 further comprises electrode pads 33a, 33b, lead electrodes 34a, 34b, and external electrodes 35a, 35b, 35c, 35d. 【0056】 The electrode pads 33a and 33b are terminals for electrically connecting to the quartz crystal oscillator 10. The electrode pads 33a and 33b are provided on the first main surface 31A near the short side of the substrate 30 in the positive X-axis direction. In the example shown in Figure 1, the electrode pads 33a and 33b are arranged away from the short side of the substrate 30 and along the direction of that short side. Electrode pad 33a is connected to the first connecting electrode 16a of the quartz crystal oscillator 10 via a conductive holding member 36a. Electrode pad 33b is connected to the second connecting electrode 16b of the quartz crystal oscillator 10 via a conductive holding member 36b. In this way, one end of the quartz crystal oscillator 10 (the end in the positive X-axis direction) is held by the electrode pads 33a and 33b and the conductive holding members 36a and 36b. Note that the electrode pads 33a and 33b and the conductive holding members 36a and 36b in this embodiment correspond to an example of a "set of holding parts" of the present invention. 【0057】The lead electrodes 34a and 34b are provided on the first main surface 31A of the base member 31. Lead electrode 34a electrically connects the electrode pad 33a and the external electrode 35a, and lead electrode 34b electrically connects the electrode pad 33b and the external electrode 35b. In addition, lead electrode 34a includes an electrode that extends in the X-axis direction near the long side on the negative Z' axis side of the four sides of the substrate 30. One end of this electrode is electrically connected to the electrode pad 33a and the external electrode 35a, but the other end is not electrically connected. 【0058】 Since the lead electrodes 34a and 34b are led out to the external electrode, intersecting the bonding region 50A, at least a portion of them overlaps with the bonding portion 50. In this embodiment, the portions where the lead electrodes 34a and 34b intersect with the bonding portion 50 are provided diagonally on the first main surface 31A of the base member 31, but this is not limited to this. For example, in a plan view, the portions where the lead electrodes 34a and 34b intersect with the bonding portion 50 may be located on the same short side or on the same long side of the first main surface 31A of the base member 31. As shown in Figures 1 and 2, the lead electrode 34b, which is led out from the electrode pad 33b and electrically connected to the external electrode 35b, extends along the X-axis direction near the long side in the positive Z' direction of the substrate 30. In this way, by extending the lead electrodes 34a and 34b from the electrode pads 33a and 33b, it is possible to prevent the adhesive of the joint 50, which will be described later, from seeping into the central region of the base member 31, and to suppress the stray capacitance within the piezoelectric vibrator. 【0059】 External electrodes 35a and 35b are external terminals for electrically connecting the quartz oscillator 10 to an external substrate (not shown). External electrode 35a electrically connects the first excitation electrode 14a of the quartz oscillator 10 to the external substrate, and external electrode 35b electrically connects the second excitation electrode 14b of the quartz oscillator 10 to the external substrate. Of the external electrodes 35c and 35d, one is a ground electrode that grounds the cover portion 40, and the other is a dummy electrode that is not electrically connected to the quartz oscillator 10 or the cover portion 40. 【0060】Each of the external electrodes 35a, 35b, 35c, and 35d is continuously provided on the second main surface 31B from the notched side surfaces provided at the four corners of the base member 31. In the example shown in Figure 1, the external electrodes 35a and 35b are located diagonally opposite each other on the first main surface 31A of the base member 31, and the external electrodes 35c and 35d are located on other diagonal sides of the first main surface 31A of the base member 31. 【0061】 The functions and positions of the external electrodes 35a, 35b, 35c, and 35d are not limited to the examples described above. Both external electrodes 35c and 35d may be ground electrodes, or both may be dummy electrodes. Furthermore, the external electrodes 35c and 35d may be omitted. External electrode 35c may be electrically connected to one of the external electrodes 35a and 35b, and 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 on the same long side of the first main surface 31A of the base member 31. 【0062】 As shown in Figure 2, the substrate 30 may further include a projection 37. The projection 37 is positioned opposite the electrode pads 33a, 33b and conductive holding members 36a, 36b with the quartz oscillator 10 in between, that is, opposite the other end of the quartz oscillator 10 (the end on the negative X-axis side). Specifically, the projection 37 is provided on the base member 31 so as to face the second main surface 11B of the quartz piece 11. 【0063】 The electrode pads 33a, 33b, lead electrodes 34a, 34b, external electrodes 35a, 35b, 35c, 35d, and projections 37 of the substrate 30 are all made of metal films. For example, the electrode pads 33a, 33b, lead electrodes 34a, 34b, external electrodes 35a, 35b, 35c, 35d, and projections 37 are each constructed by laminating a molybdenum (Mo) layer, a nickel (Ni) layer, and a gold (Au) layer from the bottom layer to the top layer. 【0064】In the crystal oscillator 1 of this configuration example, an alternating electric field is applied between a pair of first excitation electrodes 14a and second excitation electrodes 14b in the crystal oscillator element 10 via external electrodes 35a and 35b of the substrate 30. As a result, the vibrating part of the crystal piece 11 vibrates in a predetermined vibration mode, such as the thickness-slip vibration mode, and resonance characteristics associated with this vibration are obtained. 【0065】 As shown in Figure 2, the quartz oscillator 10 is held such that one end of the quartz piece 11 in the direction of its long side (the end on which the electrode pads 33a and 33b are placed) is a fixed end, and the other end is a free end. 【0066】 More specifically, the conductive holding members 36a and 36b are formed on one surface of the electrode pads 33a and 33b (the surface on the positive Y' axis side in Figure 2), and one end of the quartz oscillator 10 is held on the surface of the electrode pads 33a and 33b by the conductive holding members 36a and 36b. 【0067】 The conductive retaining members 36a and 36b are cured products of a conductive adhesive containing a thermosetting resin or a photocurable resin. The main component of the conductive retaining members 36a and 36b is, for example, silicone resin. The conductive retaining members 36a and 36b contain conductive particles, and for example, metal particles containing silver (Ag) are used as such conductive particles. 【0068】 This structure can be obtained, for example, by applying a conductive adhesive to one surface of the electrode pads 33a and 33b, and then heating and solidifying the conductive adhesive with the quartz oscillator 10 mounted on it. The solidified conductive holding members 36a and 36b electrically connect the first connecting electrode 16a and the second connecting electrode 16b of the quartz oscillator 10 to the electrode pads 33a and 33b of the substrate 30. The quartz oscillator 10 is mounted such that the second excitation electrode 14b faces the first main surface 31A of the substrate 30. 【0069】The main component of the conductive retaining members 36a and 36b is not limited to silicone resin, but may be epoxy resin, acrylic resin, or the like. Furthermore, the conductive particles contained in the conductive retaining members 36a and 36b are not limited to silver particles, but may be formed from other metals, conductive ceramics, conductive organic materials, etc. The conductive retaining members 36a and 36b may also contain conductive polymers. 【0070】 Next, the configuration of the substrate according to this embodiment will be described. 【0071】 As shown in Figures 2 to 4, the substrate 30 is provided with an insulating film 32 on the first main surface 31A. The material of the insulating film 32 is, for example, glass such as quartz (SiO2), or a resin with lower gas permeability compared to the organic adhesive in the joint 50, or a resin with a low elastic modulus and a low glass transition temperature, such as acrylic resin. The insulating film 32 made of glass material has the characteristic of less bleeding (also called "bleeding phenomenon") with respect to both the organic adhesive and the conductive adhesive mentioned above. For example, on the first main surface 31A of the base member 31, the organic adhesive contained in the joint 50 bleeds by about 100 to 200 μm. In contrast, on the insulating film 32, the bleeding of the organic adhesive is 20 μm or less. The tendency to bleed is also called bleedability. 【0072】 The insulating film 32 has a thickness of, for example, about 10 μm or less. In this embodiment, as shown in Figures 2 to 3, the insulating film 32 is formed in the bonding region 50A of the base member 31, excluding the extracted electrode exposed portions 34a1 and 34b1, which are the portions where the extracted electrodes 34a and 34b are provided. 【0073】An insulating film 32 is not formed on the exposed lead electrode portions 34a1 and 34b1. Therefore, when the substrate 30 is viewed from the positive Y' direction in plan view, the lead electrodes 34a and 34b are exposed in the exposed lead electrode portions 34a1 and 34b1. Here, "exposure" defines the relationship between the lead electrodes 34a and 34b and the insulating film 32, and it is sufficient that the lead electrodes 34a and 34b are exposed from the insulating film 32 in the above plan view. Therefore, a joint portion 50, a cover portion 40, etc. may be provided on the exposed lead electrode portions 34a1 and 34b1, and this does not exclude, for example, a state in which the lead electrodes 34a and 34b are not visible or are not exposed to air. Furthermore, as shown in Figure 4, it is desirable that the thickness of the insulating film 32 in the Y' axis direction is greater than the thickness of the extraction electrodes 34a and 34b in the Y' axis direction at the extraction electrode exposed portions 34a1 and 34b1. The organic adhesive of the joint portion 50 is bonded to the extraction electrodes 34a and 34b and the insulating film 32 at the extraction electrode exposed portions 34a1 and 34b1, and the lid portion 40 is bonded to them. Therefore, the thickness of the organic adhesive of the joint portion 50 in the Y' axis direction at the joint region 50A is the gap in the Y' axis direction between the extraction electrodes 34a and 34b and the lid portion 40 at the extraction electrode exposed portions 34a1 and 34b1, and the gap in the Y' axis direction between the insulating film 32 and the lid portion 40 at the other regions. To improve aging characteristics, it is desirable that the thickness of the organic adhesive in the Y'-axis direction of the joint 50 in these joint regions 50A be 25 μm or less. 【0074】 As described above, by forming the insulating film 32 higher in the Y' axis direction than the extraction electrodes 34a and 34b in the extracted electrode exposed portions 34a1 and 34b1, the Y' axis direction gap between the lid portion 40 and the base member 31, which is caused by the extraction electrodes 34a and 34b protruding toward the joint portion 50 in the bonding region 50A, can be filled by the insulating film 32. This makes it possible to reduce the thickness of the sealing portion of the joint portion 50 with organic adhesive, delaying the intrusion of gases (e.g., air and water vapor) from the sealing portion and improving the aging characteristics. Furthermore, the occurrence rate of leak defects caused by impurities can also be reduced. 【0075】When a material with low surface roughness, such as glass, is used for the insulating film 32, both the bleeding of the organic adhesive from the joint 50 to the substrate 30 and the bleeding of the conductive adhesive from the electrode pads 33a, 33b and conductive holding members 36a, 36b can be suppressed compared to when the organic adhesive is directly bonded to the substrate 30, which is mainly composed of ceramic. Therefore, compared to the conventional method, the clearances such as the spacing, space, gaps, and margins between members on the first main surface 31A of the base member 31 can be reduced, and the substrate 30 can be easily miniaturized. Particularly preferable is to use sintered glass for the insulating film 32, and to form the base member 31, which includes the electrode pads 33a, 33b, lead electrodes 34a, 34b, external electrodes 35a, 35b, 35c, 35d, and projections 37, as well as the metal film, from a sintered material, thereby improving the adhesion and reliability of the substrate 30. In this case, the insulating film 32 is formed, for example, by creating a pattern on an insulating glass paste containing semi-crystallized glass using screen printing or the like, then drying it with a solvent and firing it in a firing furnace. As a result, the surface of the insulating film 32 has a moderate roughness (surface roughness) and no continuous grooves are formed. 【0076】 On the other hand, in this embodiment, it is preferable that the insulating film 32 is not formed in the area approximately in the center of the first main surface 31A of the base member 31, that is, the area corresponding to the first excitation electrode 14a and the second excitation electrode 14b of the quartz oscillator 10 (not shown). This allows for a distance (space) between the quartz oscillator 10 and the first main surface 31A equal to the thickness of the insulating film 32, even if the quartz oscillator 10 has a thick vibrating part that has been beveled, thus reducing the likelihood of the vibration of the quartz oscillator 10 being hindered. 【0077】Furthermore, the region on the first main surface 31A of the base member 31 in which the insulating film 32 is formed is not limited to the example shown in Figure 2. It is sufficient that it is formed in at least the bonding region 50A, and in the bonding region 50A, it is formed while avoiding the exposed lead electrode portions 34a1 and 34b1, and the insulating film 32 may be formed in all other regions. Also, for example, in addition to the exposed lead electrode portions 34a1 and 34b1, it may be formed in the area on the first main surface 31A of the base member 31 excluding the substantially central region, and in the area excluding the electrode pads 33a and 33b. 【0078】 Furthermore, as shown in Figure 5, the insulating film 32 may also be formed on external electrodes 35a, 35b, 35c, and 35d provided on the notched side surfaces of the base member 31. In this case, the insulating film 32 formed on the notched side surfaces can prevent the organic adhesive of the joint 50 from dripping onto the notched side surfaces. Also, one end of the insulating film 32 formed in the joint region 50A may extend inward from the inner frame of the joint 50 to the outer periphery of the first main surface 31A, or it may be formed in a region approximately in the center. 【0079】 Embodiments of the present invention have been described above. According to this embodiment, the substrate 30 includes a base member 31 having a first main surface 31A for mounting the quartz oscillator 10, a bonding region 50A formed in a frame shape along the outer periphery of the first main surface 31A and bonded to a bonding portion 50 that seals the quartz oscillator 10, a metal film formed on the first main surface 31A, and an insulating film 32 formed on the first main surface 31A in a region including the bonding region 50A. The metal film also includes electrode pads 33a, 33b for holding the quartz oscillator 10, and lead electrodes 34a, 34b that are drawn out from the electrode pads 33a, 33b, intersecting the bonding region 50A and leading to external electrodes 35a, 35b. Furthermore, the bonding portion 50 is made of an organic adhesive, and the insulating film 32 is made of an insulating material with lower gas permeability than the organic adhesive of the bonding portion 50, and is formed in the bonding region 50A while avoiding the surfaces of the lead electrodes 34a, 34b. 【0080】As a result, a portion of the gap between the lower edge 43 of the lid portion 40 and the base member 31 in the joint portion 50 where the lead electrodes 34a and 34b are not formed can be filled with the insulating film 32, thereby reducing the thickness of the organic adhesive in the joint portion 50. Therefore, compared to conventional substrates, it is possible to provide a substrate that contributes to improved aging performance and a reduction in the leakage failure rate. 【0081】 Furthermore, in this embodiment, one end of the insulating film 32 formed in the bonding region 50A extends inward from the inner frame of the bonding region 50A towards the outer periphery on the first main surface 31A. 【0082】 Furthermore, in this embodiment, the insulating film 32 is formed on the first main surface 31A while avoiding the regions corresponding to the first excitation electrode 14a and the second excitation electrode 14b provided on the quartz oscillator 10. 【0083】 As a result, even if the quartz oscillator 10 has a thick beveled vibration section, for example, the distance (space) between the quartz oscillator 10 and the first main surface 31A can be increased by the thickness of the insulating film 32, making it less likely for the vibration of the quartz oscillator 10 to be hindered. 【0084】 Furthermore, in this embodiment, the thickness of the insulating film 32 is greater than the thickness of the extraction electrodes 34a and 34b. 【0085】 As a result, the Y'-axis void between the lid portion 40 and the base member 31, which is created when the lead electrodes 34a and 34b protrude in the direction of the joint portion 50 in the joint region 50A, can be filled by the insulating film 32. Therefore, the thickness of the sealing portion of the joint portion 50 with organic adhesive can be reduced, delaying the intrusion of gases (e.g., air and water vapor) from the sealing portion and improving the aging characteristics. Furthermore, the occurrence rate of leak defects caused by impurities can also be reduced. 【0086】 Furthermore, in this embodiment, the base member 31 is rectangular in shape and has notched sides at the corners, and the insulating film 32 is further formed on the notched sides. 【0087】This prevents the organic adhesive at the joint 50 from dripping onto the side of the cutout. 【0088】 Furthermore, in this embodiment, the insulating film 32 includes semi-crystallized glass. 【0089】 As a result, compared to the case where an organic adhesive is directly bonded to a ceramic-based substrate 30, both the bleeding of the organic adhesive from the bonding portion 50 to the substrate 30 and the bleeding of the conductive adhesive from the electrode pads 33a, 33b and the conductive holding members 36a, 36b can be suppressed. 【0090】 Furthermore, in this embodiment, the organic adhesive of the joint 50 is an adhesive containing an epoxy resin. 【0091】 Thus, because the organic adhesive contained in the joint 50 is an epoxy resin-based adhesive, the lid 40 and the substrate 30 can be easily joined together. 【0092】 Furthermore, in this embodiment, the device comprises a quartz oscillator 10, a substrate 30 on which the quartz oscillator 10 is mounted, a lid portion 40 provided on the side of the substrate 30 on which the quartz oscillator 10 is mounted, and a joint portion 50 provided between the lid portion 40 and the substrate 30 and sealing the quartz oscillator 10. The substrate 30 comprises a base member 31 having a first main surface 31A for mounting the quartz oscillator 10, a joint region 50A formed in a frame shape along the outer periphery of the first main surface 31A and joined to the joint portion 50 that seals the quartz oscillator 10, and a metal film formed on the first main surface 31A, the joint region The crystal oscillator 1 may include a metal film comprising electrode pads 33a and 33b arranged inside 50A and holding the crystal oscillator 10, and lead electrodes 34a and 34b drawn out from the electrode pads 33a and 33b, intersecting the bonding region 50A and leading to external electrodes 35a and 35b, and an insulating film 32 formed on the first main surface 31A in a region including the bonding region 50A, wherein the bonding portion 50 is made of an organic adhesive, and the insulating film 32 is made of an insulating material with lower gas permeability than the organic adhesive of the bonding portion 50, and is formed in the bonding region 50A while avoiding the surfaces of the lead electrodes 34a and 34b. 【0093】Furthermore, in this embodiment, the lid portion 40 may be a crystal oscillator 1 having a top wall portion 41, an opening facing the top wall portion 41, a side wall portion 42 connected to the outer edge of the top wall portion 41 and extending in a direction normal to the main surface of the top wall portion 41, and a lower edge portion 43 which is the end of the side wall portion on the opening side, with the bottom surface of the lower edge portion 43 fixed to the substrate 30 via a joint portion 50. 【0094】 Furthermore, in this embodiment, the piezoelectric vibrator may be such that the portion of the lower edge 43 of the lid portion 40 that corresponds to the portion where the lead electrodes 34a and 34b are provided has a protrusion 43A that protrudes toward the substrate 30. 【0095】 As a result, when joining the lid portion 40 to the substrate 30, the protrusion 43A fits into the recessed structure of the substrate 30, making it possible to reduce the thickness of the joining portion 50 in the area with the protrusion 43A. Furthermore, when mounting the lid portion 40A to the substrate 30, the recessed structure of the substrate 30 and the protrusion 43A make alignment easier. 【0096】 Furthermore, in this embodiment, the bottom surface of the lower edge portion 43 may be a curved surface having a apex, and the apex may be located at the center in the width direction of the bonding region 50A, thus forming a piezoelectric vibrator. 【0097】 As a result, the joint portion 50 has a fillet shape at the boundary between the lid portion 40 and the substrate 30, which makes it possible to widen the sealing width and contributes to improved adhesive stability. 【0098】 In this specification, a quartz crystal resonator comprising a quartz crystal element is used as an example of a piezoelectric element, but the piezoelectric resonator is not limited to this. Suitable piezoelectric elements for use in the piezoelectric resonator according to this embodiment include, for example, piezoelectric ceramics such as lead zirconate titanate (PZT) and aluminum nitride, and piezoelectric single crystals such as lithium niobate and lithium tantalate, but are not limited to these and can be appropriately selected. 【0099】The embodiments of the present invention are not particularly limited and can be applied as appropriate to any device that performs electromechanical energy conversion by the piezoelectric effect, such as timing devices, sound generators, oscillators, and load sensors. 【0100】 As described above, according to one aspect of the present invention, it is possible to improve airtightness. 【0101】 The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified or improved without departing from its spirit, and equivalents thereof are also included. That is, embodiments and / or modifications made by those skilled in the art are also included in the scope of the present invention, as long as they retain the features of the present invention. For example, the elements and their arrangement, materials, conditions, shapes, sizes, etc., of the embodiments and / or modifications are not limited to those exemplified and can be modified as appropriate. Furthermore, the embodiments and modifications are illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments and / or modifications is possible, and these are also included in the scope of the present invention as long as they retain the features of the present invention. 【0102】 The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified or improved without departing from its spirit, and equivalents thereof are also included. That is, any design modifications made to each embodiment by a person skilled in the art are also included within the scope of the present invention, as long as they retain the features of the present invention. For example, the elements and their arrangement, materials, conditions, shapes, sizes, etc., of each embodiment are not limited to those exemplified and can be modified as appropriate. Furthermore, each embodiment is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible, and these are also included within the scope of the present invention as long as they retain the features of the present invention. 【0103】1...Quartz oscillator 10...Quartz oscillator element 11...Quartz piece 11A...First main surface 11B...Second main surface 14a...First excitation electrode 14b...Second excitation electrode 15a...First lead electrode 15b...Second lead electrode 16a...First connection electrode 16b...Second connection electrode 30...Substrate 31...Base member 31A...First main surface 31B...Second main surface 32...Insulating film 33a, 33b...Electrode pads 34a, 34b...Lead electrodes 34a1, 34b1...Lead electrode exposed portion 35a, 35b, 35c, 35d...External electrodes 36a, 36b...Conductive holding member 37...Protrusion 39...Internal space 40, 40A...Lid portion 41...Top wall portion 42...Side wall portion 43...Lower edge portion 43A...Protrusion 44...Cap insulating film 50...Joint portion 50A...Joint region
Claims
1. A substrate comprising: a base member having a main surface for mounting a piezoelectric vibration element; a bonding region formed in a frame shape along the outer periphery of the main surface, which is bonded to a bonding portion that seals the piezoelectric vibration element; a metal film formed on the main surface, which includes an electrode pad disposed inside the bonding region and holding the piezoelectric vibration element, and a lead electrode drawn out from the electrode pad, intersecting the bonding region and leading to an external electrode; and an insulating film formed on the main surface in a region including the bonding region, wherein the bonding portion is made of an organic adhesive, and the insulating film is made of an insulating material with lower gas permeability than the organic adhesive, and is formed in the bonding region while avoiding at least a part of the surface of the lead electrode.
2. The substrate according to claim 1, wherein one end of the insulating film formed in the bonding region extends inward from the inner frame of the bonding region toward the outer periphery.
3. The substrate according to claim 1 or claim 2, wherein the insulating film is formed on the main surface, avoiding the region corresponding to the excitation electrode provided on the piezoelectric vibrating element.
4. The substrate according to any one of claims 1 to 3, wherein the thickness of the insulating film is greater than the thickness of the extraction electrode.
5. The substrate according to any one of claims 1 to 4, wherein the base member is rectangular in shape and has notched sides at the corners, and the insulating film is further formed on the notched sides.
6. The substrate according to any one of claims 1 to 5, wherein the insulating film comprises semi-crystallized glass.
7. The substrate according to any one of claims 1 to 6, wherein the organic adhesive is an adhesive containing an epoxy resin.
8. A piezoelectric vibrator comprising: a piezoelectric vibrating element; a substrate on which the piezoelectric vibrating element is mounted; a cover portion provided on the side of the substrate on which the piezoelectric vibrating element is mounted; and a joint portion provided between the cover portion and the substrate and sealing the piezoelectric vibrating element, wherein the substrate comprises: a base member having a main surface for mounting the piezoelectric vibrating element; a joint region formed in a frame shape along the outer periphery of the main surface and joined to the joint portion that seals the piezoelectric vibrating element; a metal film formed on the main surface, including an electrode pad disposed inside the joint region and holding the piezoelectric vibrating element, and a lead electrode drawn out from the electrode pad intersecting the joint region to an external electrode; and an insulating film formed on the main surface in a region including the joint region, wherein the joint portion is made of an organic adhesive, and the insulating film is made of an insulating material with lower gas permeability than the organic adhesive and is formed in the joint region avoiding at least a part of the surface of the lead electrode.
9. The piezoelectric vibrator according to claim 8, wherein the lid portion comprises: a top wall portion; an opening facing the top wall portion; a side wall portion connected to the outer edge of the top wall portion and extending in a direction normal to the main surface of the top wall portion; and a lower edge portion which is the end of the side wall portion on the opening side, and the bottom surface of the lower edge portion is fixed to the substrate via the joint portion.
10. The piezoelectric vibrator according to claim 9, wherein the portion of the lower edge of the lid that corresponds to the portion on which the lead-out electrode is provided has a protrusion that protrudes toward the substrate.
11. The piezoelectric vibrator according to claim 9 or claim 10, wherein the bottom surface of the lower edge portion is curved and has a apex, and the apex is located at the center in the width direction of the joining region.