Piezoelectric vibration device

Abstract

The present invention suppresses creep-up toward a communication part formed in a second sealing member of a joining material for joining an external terminal of a piezoelectric vibrator and a mounting pad of a substrate.　The present invention comprises: a piezoelectric vibrator 3 which is provided with a piezoelectric vibration plate 10 and first and second sealing members 20, 30 for hermetically sealing a vibration part 11 of the piezoelectric vibration plate 10, and which has a first external terminal 32a formed on a second main surface 302 of the second sealing member 30; a substrate 2 on which a first pad 52a for mounting the piezoelectric vibrator 3 is formed; solder H which joins the first external terminal 32a and the first pad 52a; and a resin mold part 5 which is molded onto the substrate 2 so as to cover the piezoelectric vibrator 3. The second sealing member 30 has a penetration part 33a1 connected to a first region 32a1 of the first external terminal 32a. A through electrode 33a2 is formed in the penetration part 33a1. A metal material on the surface of the first region 32a1 is less likely to be wetted by the solder H than the metal material on the surface of a second region 32a2 of the first external terminal 32a.

Description

Piezoelectric Vibration Device

[0001] The present invention relates to a piezoelectric vibration device including a substrate and a piezoelectric vibrator mounted on a mounting surface of the substrate.

[0002] An example of a piezoelectric vibration device is the piezoelectric vibration device disclosed in Patent Document 1. The piezoelectric vibration device disclosed in Patent Document 1 includes a substrate, and a piezoelectric vibrator and electronic components mounted on the mounting surface of the substrate. A plurality of external connection terminals are formed on the surface (external bottom surface) of the piezoelectric vibrator facing the substrate, and a plurality of piezoelectric vibrator mounting pads corresponding to the plurality of external connection terminals are formed on the mounting surface of the substrate. The plurality of external connection terminals formed on the external bottom surface of the piezoelectric vibrator are solder-bonded to corresponding piezoelectric vibrator mounting pads among a plurality of piezoelectric vibrator mounting pads formed on the mounting surface of the substrate.

[0003] Another example of a piezoelectric vibrator is a so-called sandwich-structured piezoelectric vibrator, which is disclosed, for example, in Patent Document 2. The sandwich-structured piezoelectric vibrator disclosed in Patent Document 2 includes a piezoelectric diaphragm having a first excitation electrode formed on one main surface and a second excitation electrode paired with the first excitation electrode formed on the other main surface, a first sealing member covering the first excitation electrode of the piezoelectric diaphragm, and a second sealing member covering the second excitation electrode of the piezoelectric diaphragm, and by bonding the first sealing member to the piezoelectric diaphragm and also bonding the second sealing member to the piezoelectric diaphragm, an internal space is provided in which a vibration part of the piezoelectric diaphragm including the first excitation electrode and the second excitation electrode is hermetically sealed, and a plurality of external terminals are formed on the other main surface of the second sealing member opposite to the one main surface facing the piezoelectric diaphragm. The piezoelectric vibrator includes a first excitation electrode and a second excitation electrode of the piezoelectric diaphragm, and a second excitation electrode of the piezoelectric diaphragm is electrically connected to the first excitation electrode and the second excitation electrode by a through-hole formed on an inner wall surface of the through-hole extending from one main surface to the other main surface of the second sealing member and connected to the external terminal. When the piezoelectric vibrator is mounted on a substrate, the external terminal is electrically connected to a piezoelectric vibrator mounting pad formed on the substrate via solder.

[0004] Incidentally, sandwich-structured piezoelectric vibrators are advantageous for miniaturization and have stable characteristics after hermetically sealing. For this reason, sandwich-structured piezoelectric vibrators are suitable for packaging configurations in which they are combined with electronic components such as an integrated circuit (IC) for an oscillation circuit and mounted on the mounting surface of a substrate using solder, and the piezoelectric vibrator and electronic components are sealed with resin.

[0005] JP 2007-173431 A International Publication No. 2020 / 137830

[0006] However, in the case of sandwich-structured piezoelectric vibrators, when the piezoelectric vibrator device is soldered to an external circuit board or the like through a reflow oven using reflow soldering or the like, the piezoelectric vibrator device is reheated. As a result, the solder connecting the external terminals of the piezoelectric vibrator built into the piezoelectric vibrator device to the piezoelectric vibration mounting pads on the board is also reheated and remelted. The remelted solder is prone to creeping up. In particular, in the case of piezoelectric vibrators covered with a resin molded portion, the piezoelectric vibrator is surrounded by the resin molded around it, and therefore has no escape route other than the through-hole formed in the second sealing member. Therefore, there is a risk of the solder creeping up to the through-hole formed in the second sealing member and even to the sealing portion where the piezoelectric diaphragm and the second sealing member are joined. In particular, the solder that creeps up to the through-hole may diffuse to the through-hole electrode, which may lead to a decrease in electrical connectivity between the electrodes (e.g., first excitation electrode, second excitation electrode) and the corresponding external terminals, impede the vibration of the piezoelectric diaphragm, and cause airtightness problems due to corrosion of the metal material of the first sealing member and the second sealing member.

[0007] In view of the above problems, the present invention aims to provide a piezoelectric vibration device that can suppress creeping up to a connecting portion formed by a through portion or notch formed in a second sealing member of a bonding material that joins the external terminal of a piezoelectric vibrator to a mounting pad of a substrate.

[0008] In order to achieve the above object, a piezoelectric vibration device according to the present invention comprises a piezoelectric vibration plate on which electrodes are formed, and a pair of first and second sealing members that sandwich the piezoelectric vibration plate to hermetically seal a vibration portion of the piezoelectric vibration plate, a piezoelectric vibrator having external terminals formed on one main surface of the second sealing member that faces the piezoelectric vibration plate and the other main surface opposite the other main surface, a substrate having mounting pads on its mounting surface on which the piezoelectric vibrator is mounted, and a metal brazing material that bonds the external terminals and the mounting pads, The member has a connecting portion formed by a through portion or a notch portion extending from the one main surface to the other main surface and connecting to the external terminal formed on the other main surface, and a connection electrode is formed in the connecting portion and forms part of a conductive path connecting the external terminal and the electrode, and in a planar view, the external terminal has a first region connected to the connecting portion and a second region having a metal material composition different from that of the first region, and the metal material on the surface of the first region is less likely to be wetted by the metal brazing material than the metal material on the surface of the second region.

[0009] According to this configuration, in a plan view, the metal material on the surface of the first region that connects to the connecting portion of the external terminal is made of a material that is less wettable by the metal brazing material (a state in which the metal brazing material is less likely to flow and adapt to the metal surface) than the metal material of the second region that is not connected to the connecting portion of the external terminal.This makes it possible to suppress the flow of the metal brazing material around the overlapping region, thereby reducing the amount of metal brazing material that overlaps the connecting portion and suppressing the metal brazing material from creeping up to the connecting portion.

[0010] In this case, it is preferable that the piezoelectric transducer further includes a resin molded portion molded on the mounting surface of the substrate so as to cover the piezoelectric vibrator mounted on the mounting surface of the substrate.

[0011] The area of ​​the second region in a plan view may be larger than the area of ​​the first region in a plan view.

[0012] According to this configuration, by making the area of ​​the second region in a planar view of the external terminal, in which the metal material on the surface is more easily wetted by the metal brazing material, larger than the area of ​​the first region in a planar view, it is possible to increase the area of ​​the region where the second region, in a planar view, whose surface is made of a metal material that is more easily wetted by the metal brazing material, and the mounting pad overlap, thereby improving the electrical connection between the external terminal and the mounting pad via the metal brazing material.

[0013] The external terminal may be formed such that, in a plan view, the second region is closer to the approximate center of the mounting pad than the first region.

[0014] With this configuration, it is possible to increase the amount of metal brazing material in the area where the second region, whose surface is made of a metal material that is easily wetted by metal brazing material when viewed in a plane, overlaps with the mounting pad, thereby improving the electrical connection between the external terminal and the mounting pad via the metal brazing material.

[0015] According to the present invention, when viewed in a plane, the metal material on the surface of the first region that is connected to the connecting portion of the external terminal is made of a material that is less wettable by the metal brazing material (a state in which the metal brazing material is less likely to flow and adapt to the metal surface) than the metal material of the second region that is not connected to the connecting portion of the external terminal.This makes it possible to suppress the flow of the metal brazing material around the overlapping region, thereby reducing the amount of metal brazing material that overlaps the connecting portion and suppressing the metal brazing material from creeping up to the connecting portion.

[0016] 1 is a schematic plan view of the top surface side of a piezoelectric vibration device excluding a sealing resin according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the bottom surface side of the piezoelectric vibration device (substrate of FIG. 1) of FIG. 1. FIG. 3 is a schematic cross-sectional view of the piezoelectric vibration device along line A-A of FIG. 1 with sealing resin added. FIG. 4 is a schematic plan view of the top surface side (first main surface side of a first sealing member provided in the piezoelectric vibrator of FIG. 1) of the piezoelectric vibrator of FIG. 1. FIG. 5 is a schematic plan view of the second main surface side of the first sealing member provided in the piezoelectric vibrator of FIG. 1. FIG. 6 is a schematic plan view of the first main surface side of a piezoelectric diaphragm provided in the piezoelectric vibrator of FIG. 1. FIG. 7 is a schematic plan view of the second main surface side of the piezoelectric diaphragm provided in the piezoelectric vibrator of FIG. 1. FIG. 8 is a schematic plan view of the first main surface side of a second sealing member provided in the piezoelectric vibrator of FIG. 1. FIG. 9 is a schematic plan view of the bottom surface side (second main surface side of the second sealing member provided in the piezoelectric vibrator of FIG. 1). FIG. 10 is a schematic plan view of the top surface (mounting surface) side of the substrate of FIG. 1. FIG. 11 is a schematic cross-sectional view of a through hole formed in the second sealing member provided in the piezoelectric vibrator of FIG. 1. 1. A diagram for explaining the positional relationship between first to fourth external terminals of a second sealing member provided in the piezoelectric vibrator of FIG. 1 and three through holes formed in the second sealing member, and first to fourth piezoelectric vibrator mounting pads formed on the upper surface of a substrate. A diagram for explaining the positional relationship between the first to fourth external terminals and through holes, and first to fourth piezoelectric vibrator mounting pads in Modification 1. A diagram for explaining the positional relationship between the first to fourth external terminals and through holes, and first to fourth piezoelectric vibrator mounting pads in Modification 2. A diagram for explaining the positional relationship between the first to fourth external terminals and castellations, and first to fourth piezoelectric vibrator mounting pads in Modification 3.

[0017] A piezoelectric vibration device according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 12. FIG.

[0018] As shown in Figures 1 to 3, the piezoelectric vibration device 1 comprises a substrate (corresponding to the "substrate" of the present invention) 2, a piezoelectric vibrator (corresponding to the "piezoelectric vibrator" of the present invention) 3 and an electronic component 4 mounted on an upper surface (corresponding to the "mounting surface" of the present invention) 2a of the substrate 2, solder (corresponding to the "bonding material" of the present invention) H, and a resin molded portion (corresponding to the "resin molded portion" of the present invention) 5 molded on the upper surface 2a of the substrate 2 so as to cover the piezoelectric vibrator 3 and the electronic component 4.

[0019] 3, the piezoelectric vibrator 3 includes a piezoelectric diaphragm 10 (corresponding to the "piezoelectric diaphragm" of the present invention), a first sealing member 20 (corresponding to the "first sealing member" of the present invention), and a second sealing member 30 (corresponding to the "second sealing member" of the present invention). In the piezoelectric vibrator 3, the piezoelectric diaphragm 10 and the first sealing member 20 are bonded together, and the piezoelectric vibrator 3 is bonded to the second sealing member 30, thereby forming a package with a substantially rectangular parallelepiped sandwich structure. That is, in the piezoelectric vibrator 3, the first sealing member 20 and the second sealing member 30 are bonded to both main surfaces of the piezoelectric diaphragm 10, respectively, to form an internal space (cavity) of the package, and the vibrating section 11 (see FIGS. 6 and 7) is hermetically sealed in this internal space.

[0020] The piezoelectric vibrator 3 according to this embodiment has a package size of, for example, 1.0 mm x 0.8 mm, and is designed to be compact and low-profile. In addition, first to fourth external terminals 32 a to 32 d (described later) of the piezoelectric vibrator 3 are electrically connected via solder H to first to fourth piezoelectric vibrator mounting pads 52 a to 52 d (described later) formed on the upper surface 2 a of the substrate 2 (see FIG. 3).

[0021] Next, the piezoelectric diaphragm 10, the first sealing member 20, and the second sealing member 30 that make up the piezoelectric vibrator 3 will be described with reference to Figures 3 to 9. Note that the description here focuses on each of the components that are configured as individual components that are not joined together. Figures 4 to 9 merely show examples of the configuration of the piezoelectric diaphragm 10, the first sealing member 20, and the second sealing member 30, and do not limit the present invention.

[0022] First, the piezoelectric diaphragm 10 will be described with reference to FIGS.

[0023] The piezoelectric diaphragm 10 is a piezoelectric substrate made of quartz crystal, and both of its main surfaces (first main surface 101 and second main surface 102) are formed as flat, smooth surfaces (mirror-finished). In this embodiment, an AT-cut quartz crystal plate that performs thickness-shear vibration is used as the piezoelectric diaphragm 10. In the piezoelectric diaphragm 10 shown in Figures 6 and 7, both main surfaces (first main surface 101 and second main surface 102) of the piezoelectric diaphragm 10 are in the XZ' plane. In this XZ' plane, the direction parallel to the short side (short side direction) of the piezoelectric diaphragm 10 is the X-axis direction, and the direction parallel to the long side (long side direction) of the piezoelectric diaphragm 10 is the Z'-axis direction. Note that AT-cut is a processing technique in which artificial quartz crystal is cut at an angle of 35°.15' around the X-axis with respect to the Z-axis, which is one of the three crystal axes of the artificial quartz crystal: the electrical axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). In an AT-cut quartz plate, the X-axis coincides with the crystal axis of the quartz. The Y'-axis and Z'-axis coincide with axes tilted approximately 35°15' from the Y-axis and Z-axis, respectively (this cutting angle may be changed slightly within the range required to adjust the frequency-temperature characteristics of the AT-cut quartz plate). The Y'-axis and Z'-axis directions correspond to the cutting direction when the AT-cut quartz plate is cut.

[0024] The piezoelectric diaphragm 10 includes a substantially rectangular vibration portion 11, a thicker outer frame portion 12 that surrounds the outer periphery of the vibration portion 11 with a gap therebetween, and a retaining portion 13 that connects the vibration portion 11 to the outer frame portion 12 and holds the vibration portion 11. That is, the piezoelectric diaphragm 10 is configured such that the vibration portion 11, the outer frame portion 12, and the retaining portion 13 are integrally formed. The retaining portion 13 extends (protrudes) from only one corner of the vibration portion 11 located in the +X direction and the -Z' direction toward the outer frame portion 12 in the -Z' direction. A cutout portion 10a is formed by cutting out the piezoelectric diaphragm 10 between the vibration portion 11 and the outer frame portion 12. In this embodiment, the piezoelectric diaphragm 10 includes only one retaining portion 13 that connects the vibration portion 11 to the outer frame portion 12, and the cutout portion 10a is continuously formed to surround the outer periphery of the vibration portion 11. In this embodiment, the piezoelectric diaphragm 10 is configured so that no through-holes or castellations are provided in the outer frame portion 12. The piezoelectric diaphragm 10 is configured so that it does not have any through-holes other than the cutout portion 10a.

[0025] A rectangular first excitation electrode 111 is formed on the vibrating portion 11 of the first main surface 101 of the piezoelectric diaphragm 10. A rectangular second excitation electrode 112 that pairs with the first excitation electrode 111 is formed on the vibrating portion 11 of the second main surface 102 of the piezoelectric diaphragm 10. The first excitation electrode 111 and the second excitation electrode 112 are not limited to being rectangular in shape and may be, for example, rhombic or elliptical. The first excitation electrode 111 and the second excitation electrode 112 are not limited to being the same shape and may be different shapes, for example, the first excitation electrode 111 may be rectangular and the second excitation electrode 112 may be rhombic.

[0026] A first lead wiring 113 for connecting the first excitation electrode 111 to the first external terminal 32a is formed on the first main surface 101 of the piezoelectric diaphragm 10. In addition, a connection bonding pattern 12a is formed on the outer frame portion 12 of the first main surface 101 of the piezoelectric diaphragm 10. The first lead wiring 113 is led out from the first excitation electrode 111 on the first main surface 101 of the piezoelectric diaphragm 10, and is connected to the connection bonding pattern 12a via a holding portion 13 of the first main surface 101 of the piezoelectric diaphragm 10. In addition, connection bonding patterns 12b and 12c are formed on the outer frame portion 12 of the first main surface 101 of the piezoelectric diaphragm 10.

[0027] A second extraction wiring 114 for connecting the second excitation electrode 112 to the second external terminal 32b is formed on the second main surface 102 of the piezoelectric diaphragm 10. A connection bonding pattern 12d is also formed on the outer frame portion 12 portion of the second main surface 102 of the piezoelectric diaphragm 10. The second extraction wiring 114 is extracted from the second excitation electrode 112 on the second main surface 102 of the piezoelectric diaphragm 10, and is connected to the connection bonding pattern 12d via the holding portion 13 portion of the second main surface 102 of the piezoelectric diaphragm 10. Connection bonding patterns 12e and 12f are also formed on the outer frame portion 12 portion of the second main surface 102 of the piezoelectric diaphragm 10.

[0028] Furthermore, internal wiring 12g is formed on the inner wall surface of the outer frame portion 12 of the piezoelectric diaphragm 10. The connection bonding pattern 12a is connected to the connection bonding pattern 12e via the internal wiring 12g. The internal wiring 12g is provided on the inner wall surface of the outer frame portion 12 that is along the X-axis direction and is on the inner wall surface on the -Z' direction side. In this case, the internal wiring 12g is formed in a V-shaped recess in a plan view provided on the inner wall surface of the outer frame portion 12. In this way, by forming a V-shaped recess on the inner wall surface of the outer frame portion 12, the internal wiring 12g can be formed in a state that is aligned with a direction other than the X-axis direction of the AT cut. Therefore, even if an inclined surface is formed in the wet etching process, portions other than acute angles will also appear, thereby reducing the risk of wire breakage, etc.

[0029] A vibration-plate-side first bonding pattern 121 is provided on the first main surface 101 of the piezoelectric vibration plate 10 as a vibration-side sealing portion for bonding the piezoelectric vibration plate 10 to the first sealing member 20. The vibration-plate-side first bonding pattern 121 is formed in a ring shape in a plan view on the outer frame portion 12 portion of the first main surface 101 of the piezoelectric vibration plate 10. The outer peripheral edge of the vibration-plate-side first bonding pattern 121 is provided close to the outer peripheral edge of the first main surface 101 of the piezoelectric vibration plate 10 (outer frame portion 12). The vibration-plate-side first bonding pattern 121 is electrically connected to a third external terminal 32 serving as a ground terminal, which will be described later, and functions as an earth electrode.

[0030] A diaphragm-side second bonding pattern 122 is provided on the second main surface 102 of the piezoelectric diaphragm 10 as a vibration-side sealing portion for bonding the piezoelectric diaphragm 10 to the second sealing member 30. The diaphragm-side second bonding pattern 122 is formed in a ring shape in a plan view on the outer frame portion 12 portion of the second main surface 102 of the piezoelectric diaphragm 10. The outer peripheral edge of the diaphragm-side second bonding pattern 122 is provided close to the outer peripheral edge of the second main surface 102 of the piezoelectric diaphragm 10 (outer frame portion 12). The diaphragm-side second bonding pattern 122 is electrically connected to a third external terminal 32 serving as a ground terminal (described later) and functions as an earth electrode. The first excitation electrode 111 or the second excitation electrode 112, or the diaphragm-side first and second bonding patterns 121-122 correspond to "electrodes" in the present invention.

[0031] Furthermore, internal wiring 17 is formed on the inner wall surface of the outer frame portion 12 of the piezoelectric diaphragm 10. The diaphragm-side first bonding pattern 121 and the diaphragm-side second bonding pattern 122 are connected via the internal wiring 17. The internal wiring 17 is provided on the inner wall surface of the outer frame portion 12 that is along the Z'-axis direction and on the inner wall surface on the -X direction side, and is provided on the inner wall surface that is perpendicular to the inner wall surface on which the above-mentioned internal wiring 12g is provided.

[0032] Next, the first sealing member 20 will be described with reference to FIGS.

[0033] The first sealing member 20 is a substantially rectangular parallelepiped substrate formed from a single AT-cut quartz crystal plate. The second main surface 202 (the surface bonded to the piezoelectric diaphragm 10) of the first sealing member 20 is formed as a flat, smooth surface (mirror-finished). Although the first sealing member 20 does not have a vibrating portion, the use of an AT-cut quartz crystal plate, like the piezoelectric diaphragm 10, allows the piezoelectric diaphragm 10 and the first sealing member 20 to have the same thermal expansion coefficient, thereby suppressing thermal deformation of the piezoelectric vibrator 3. The X-, Y'-, and Z'-axes of the first sealing member 20 are also aligned in the same direction as those of the piezoelectric diaphragm 10. In this embodiment, the first sealing member 20 does not have through-holes or castellations, significantly shortening the manufacturing process for the first sealing member 20. Furthermore, the first sealing member 20 eliminates a path for moisture to enter the internal space of the package, thereby improving corrosion resistance.

[0034] In this embodiment, no electrodes or the like are formed on the first main surface 201 of the first sealing member 20 .

[0035] A sealing-member-side first bonding pattern 24 is provided on the second main surface 202 of the first sealing member 20 as a sealing-member-side sealing portion for bonding to the piezoelectric diaphragm 10. The sealing-member-side first bonding pattern 24 is formed in a ring shape in a plan view. The outer peripheral edge of the sealing-member-side first bonding pattern 24 is provided close to the outer peripheral edge of the second main surface 202 of the first sealing member 20. In a plan view, the vibration-plate-side first bonding pattern 121 on the piezoelectric diaphragm 10 side and the sealing-member-side first bonding pattern 24 on the first sealing member 20 side are provided in a position where they overlap.

[0036] Connection bonding patterns 22a, 22b, and 22c are formed on the second main surface 202 of the first sealing member 20 to bond to the connection bonding patterns 12a, 12b, and 12c formed on the outer frame portion 12 of the first main surface 101 of the piezoelectric diaphragm 10. In a plan view, these patterns are provided at positions where the connection bonding patterns 12a, 12b, and 12c on the piezoelectric diaphragm 10 side overlap with the connection bonding patterns 22a, 22b, and 22c on the first sealing member 20 side, respectively.

[0037] Finally, the second sealing member 30 will be described with reference to FIGS.

[0038] The second sealing member 30 is a substantially rectangular parallelepiped substrate made of an AT-cut quartz crystal plate, and a first main surface 301 (the surface that bonds to the piezoelectric diaphragm 10) of this second sealing member 30 is formed as a flat, smooth surface (mirror-finished). Note that the second sealing member 30 also uses an AT-cut quartz crystal plate like the piezoelectric diaphragm 10, and it is desirable that the orientations of the X-axis, Y'-axis, and Z'-axis are the same as those of the piezoelectric diaphragm 10.

[0039] A sealing-member-side second bonding pattern 31 is provided on a first main surface (corresponding to "one main surface" in the present invention) 301 of the second sealing member 30 as a sealing-member-side sealing portion for bonding to the piezoelectric diaphragm 10. The sealing-member-side second bonding pattern 31 is formed in a ring shape in a plan view. The outer peripheral edge of the sealing-member-side second bonding pattern 31 is provided close to the outer peripheral edge of the first main surface 301 of the second sealing member 30. In a plan view, the vibration-plate-side second bonding pattern 122 on the piezoelectric diaphragm 10 side and the sealing-member-side second bonding pattern 31 on the second sealing member 30 side are provided at a position where these patterns overlap.

[0040] Connection bonding patterns 34a, 34b, and 34c are formed on the first main surface 301 of the second sealing member 30 to bond to the connection bonding patterns 12d, 12e, and 12f formed on the outer frame portion 12 of the second main surface 102 of the piezoelectric diaphragm 10. In a plan view, these patterns are provided at positions where the connection bonding patterns 12d, 12e, and 12f on the piezoelectric diaphragm 10 side overlap with the connection bonding patterns 34a, 34b, and 34c on the second sealing member 30 side, respectively. In addition, a wiring pattern 35 extending in the Z′-axis direction is connected to the first main surface 301 of the second sealing member 30, connecting the connection bonding pattern 34a and the connection bonding pattern 34c.

[0041] First to fourth external terminals 32a to 32d are provided on the second main surface 302 (corresponding to the "other main surface" of the present invention) of the second sealing member 30. The first to fourth external terminals 32a to 32d are formed in a substantially rectangular shape in a plan view and are located at the four corners (corner portions) of the second main surface 302 of the second sealing member 30. However, the fourth external terminal 32d has a chamfered C-surface (corner surface) that serves as an indicator for the mounting direction of the piezoelectric vibrator 3. Note that this indicator is not limited to a chamfered C-surface (corner surface), and may be, for example, a chamfered R-surface (rounded surface) or a protrusion. The first to fourth external terminals 32a to 32d are provided in positions that overlap the outer frame portion 12 of the piezoelectric diaphragm 10 described above in a plan view. The first external terminal 32a is an input terminal, and the second external terminal 32b is an output terminal. The third and fourth external terminals 32c and 32d are ground terminals. The first to third external terminals 32a to 32c correspond to the "external terminals" of the present invention.

[0042] The first to fourth external terminals 32a to 32d each have a first region 32a1 to 32d1 and a second region 32a2 to 32d2 in a plan view, and the first regions 32a1 to 32d1 are made of a different metal material than the second regions 32a2 to 32d2, as will be described later. The first regions 32a1 to 32c1 include at least overlapping regions that overlap with the penetrating electrodes 33a2 to 33c2 of the through holes 33a to 33c, respectively, and peripheral regions surrounding the overlapping regions. In a plan view, the first region 32a1 is located near the end of the first external terminal 32a on the +X side and the -Z' side, the first region 32b1 is located near the end of the second external terminal 32b on the -X side and the +Z' side, the first region 32c1 is located near the end of the third external terminal 32c on the +X side and the +Z' side, and the first region 32d1 is located near the end of the fourth external terminal 32d on the -X side and the -Z' side. Note that the first regions 31a1 to 31c1 correspond to the "first region" in the present invention, and the second regions 31a2 to 31c2 correspond to the "second region" in the present invention.

[0043] The second sealing member 30 has three through holes 33a, 33b, and 33c formed between the first main surface 301 and the second main surface 302. The through holes 33a and 33b are configured to include penetration portions 33a1 and 33b1 that penetrate the second sealing member 30 and penetration electrodes 33a2 and 33b2 that are formed along the inner wall surfaces of the penetration portions 33a1 and 33b1 and that establish electrical continuity between the connection bonding patterns 34b and 34c and the first and second external terminals 32a and 32b. The through hole 33c is configured to include a penetration portion 33c1 that penetrates the second sealing member 30 and a penetration electrode 33c2 that is formed along the inner wall surface of the penetration portion 33c1 and that establishes electrical continuity between the sealing member-side second bonding pattern 31 and the third external terminal 32c. The central portion of each of the through holes 33a, 33b, and 33c is a hollow penetrating portion that penetrates between the first main surface 301 and the second main surface 302. The connection bonding pattern 12a, the internal wiring 12g, the connection bonding pattern 12e, the connection bonding pattern 34b, and the penetrating electrode 33a2 form a conductive path CD1 that electrically connects the first excitation electrode 111 and the first external terminal 32a, and the connection bonding pattern 12d, the connection bonding pattern 34a, the wiring pattern 35, and the penetrating electrode 33b2 form a conductive path CD2 that electrically connects the second excitation electrode 112 and the first external terminal 32b. The penetrating portions 33a1, 33b1, and 33c1 correspond to the "communicating portion" and "penetrating portion" of the present invention, and the penetrating electrodes 33a2, 33b2, and 33c2 correspond to the "connecting electrodes" that form part of the conductive paths CD1 and CD2 of the present invention. The through holes 33a, 33b, and 33c will be described in detail later.

[0044] The through holes 33a, 33b, 33c (penetrating portions 33a1, 33b1, 33c1 of the through holes 33a, 33b, 33c) are connected to first regions 32a1, 32b1, 32c1 of the first to third external terminals 32a, 32b, 32c.

[0045] In the piezoelectric vibrator 3 including the piezoelectric diaphragm 10, first sealing member 20, and second sealing member 30 configured as described above, the piezoelectric diaphragm 10 and the first sealing member 20 are diffusion bonded with the diaphragm-side first bonding pattern 121 and the sealing member-side first bonding pattern 24 overlapping each other, and the piezoelectric diaphragm 10 and the second sealing member 30 are diffusion bonded with the diaphragm-side second bonding pattern 122 and the sealing member-side second bonding pattern 31 overlapping each other, thereby manufacturing a sandwich-structured package as shown in Fig. 3. This forms an internal space in which the vibration portion 11 of the piezoelectric diaphragm 10, including the first excitation electrode 111 and the second excitation electrode 112, is hermetically sealed.

[0046] At this time, the connection bonding patterns 22a, 22b, and 22c formed on the second main surface 202 of the above-mentioned first sealing member 20 and the connection bonding patterns 12a, 12b, and 12c formed on the first main surface 101 of the piezoelectric diaphragm 10 are diffusion bonded in an overlapping state, and the connection bonding patterns 12d, 12e, and 12f formed on the second main surface 102 of the piezoelectric diaphragm 10 and the connection bonding patterns 34a, 34b, and 34c formed on the first main surface 301 of the second sealing member 30 are diffusion bonded in an overlapping state. This provides electrical conductivity between the first excitation electrode 111 and the first external terminal 32a, and electrical conductivity between the second excitation electrode 112 and the second external terminal 32b. Specifically, the first excitation electrode 111 is connected to the first external terminal 32a via the first escape wiring 113, the connection bonding pattern 12a, the internal wiring 12g, the connection bonding pattern 12e, the connection bonding pattern 34b, and the through electrode 33a2 of the through hole 33a, in that order. The second excitation electrode 112 is connected to the second external terminal 32b via the second escape wiring 114, the connection bonding pattern 12d, the connection bonding pattern 34a, the wiring pattern 35, the connection bonding pattern 34c, and the through electrode 33b2 of the through hole 33b, in that order.

[0047] In addition, the third external terminal 32c is connected to the penetrating electrode 33c2 of the through hole 33c, the second bonding pattern 31 on the sealing member side, the second bonding pattern 122 on the vibration plate side, the internal wiring 17, the first bonding pattern 121 on the vibration plate side, and the first bonding pattern 24 on the sealing member side.

[0048] In the piezoelectric vibrator 3, the various bonding patterns (sealing member side first bonding pattern 24, connection bonding patterns 22a, 22b, 22c, vibration plate side first bonding pattern 121, connection bonding patterns 12a, 12b, 12c, vibration plate side second bonding pattern 122, connection bonding patterns 12d, 12e, 12f, sealing member side second bonding pattern 31, connection bonding patterns 34a, 34b, 34c, etc.) and wiring patterns (wiring pattern 35, etc.) are formed by stacking multiple metal layers on a quartz plate, and from the bottom layer onwards, a Ti (titanium) metal layer and an Au (gold) metal layer are formed in that order by vapor deposition or sputtering. In addition, the electrodes (first excitation electrode 111, second excitation electrode 112), wiring (first outgoing wiring 113, second outgoing wiring 114, internal wiring 12g, 17, etc.), and portions of the external terminals (second regions 32a2 to 32d2 of the first to fourth external terminals 32a to 32d, etc.) formed on the piezoelectric vibrator 3 are made by stacking multiple metal layers on a quartz plate, with a Ti (titanium) metal layer and an Au (gold) metal layer formed in that order from the bottom layer side by vapor deposition or sputtering.

[0049] The remaining portions of the external terminals (such as the first regions 32a1 to 32d1 of the first to fourth external terminals 32a to 32d) and the through electrodes formed on the inner wall surfaces of the through holes (such as the through electrodes 33a2 to 33c2 formed on the inner wall surfaces of the through holes 33a to 33c) consist only of a Ti (titanium) metal layer on the quartz plate.

[0050] As described above, the first regions 32a1-32d1 consist solely of a Ti (titanium) metal layer on the quartz plate, while the second regions 32a2-32d2 consist of a Ti (titanium) metal layer and an Au (gold) metal layer stacked in this order on the quartz plate. Thus, the Ti (titanium) on the surfaces of the first regions 32a1-32d1 is an electrode material that is less wettable with brazing filler metals such as solder H, while the Au (gold) on the surfaces of the second regions 32a2-32d2 is an electrode material that is more wettable with brazing filler metals such as solder H. In other words, the metal material on the surfaces of the first regions 32a1-32d1 is less wettable with brazing filler metals such as solder H than the metal material on the surfaces of the second regions 32a2-32d2.

[0051] 11, through hole 33a is formed so that its diameter decreases from first main surface 301 toward the center in the thickness direction of second sealing member 30, and increases from the center in the thickness direction of second sealing member 30 toward second main surface 302. Through holes 33b and 33c have the same structure as through hole 33a.

[0052] In the piezoelectric vibrator 3 configured as described above, the sealing portion (seal paths 15, 16 shown in FIG. 3 ) that hermetically seals the vibration portion 11 of the piezoelectric diaphragm 10 is formed in an annular shape in a plan view. The seal path 15 is formed by diffusion bonding (Au-Au bonding) between the above-described vibration plate-side first bonding pattern 121 and the sealing member-side first bonding pattern 24. The outer edge shape of the seal path 15 is formed in a substantially rectangular shape, and the outer periphery of the seal path 15 is disposed close to the outer periphery of the package. Similarly, the seal path 16 is formed by diffusion bonding (Au-Au bonding) between the above-described vibration plate-side second bonding pattern 122 and the sealing member-side second bonding pattern 31. The outer edge shape of the seal path 16 is formed in a substantially rectangular shape, and the outer periphery of the seal path 16 is disposed close to the outer periphery of the package. The seal paths 15 and 16 are not electrically connected to the electrical conduction paths between the first and second excitation electrodes 111 and 112 and the first and second external terminals 32 a and 32 b. Specifically, the seal path 15 is connected to the seal path 16 via the internal wiring 17, and the seal path 16 is connected to earth (ground connection, using the third external terminal 32 c, etc.) via the penetrating electrode 33 c 2 of the through hole 33 c.

[0053] In the piezoelectric vibrator 3 in which the seal paths 15, 16 are formed by diffusion bonding in this manner, the first sealing member 20 and the piezoelectric diaphragm 10 have a gap of 1.00 μm or less, and the second sealing member 30 and the piezoelectric diaphragm 10 have a gap of 1.00 μm or less. In other words, the thickness of the seal path 15 between the first sealing member 20 and the piezoelectric diaphragm 10 is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm for the Au-Au bonding of this embodiment), and the thickness of the seal path 16 between the second sealing member 30 and the piezoelectric diaphragm 10 is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm for the Au-Au bonding of this embodiment). For comparison, a conventional metal paste sealing material using Sn has a thickness of 5 μm to 20 μm. For comparison, a sealing material made of a brazing material using an AuSn alloy has a thickness of 5 μm to 20 μm.

[0054] The electronic component 4 is an IC (Integrated Circuit) that controls the piezoelectric vibrator 3, and is mounted by wire bonding on the upper surface 2a of the substrate 2. The electronic component 4 has an electronic circuit such as an oscillation circuit that generates a predetermined oscillation output, and outputs the oscillation output generated by the oscillation circuit to the outside as a reference signal such as a clock signal.

[0055] 1, first to sixth external terminals 4a to 4f, each having a substantially rectangular shape in a plan view, are formed on the top surface of the electronic component 4. The first to sixth external terminals 4a to 4f are, for example, the following terminals: the first external terminal 4a is a clock input terminal, the second external terminal 4b is a ground terminal, and the third external terminal 4c is an oscillation output terminal. The fourth external terminal 4d is a clock output terminal, the fifth external terminal 4e is an output enable terminal, and the sixth external terminal 4f is a power supply terminal. The first to sixth external terminals 4a to 4f are electrically connected by wires to first to sixth electronic component connecting pads 53a to 53f formed on the top surface 2a of the substrate 2.

[0056] The substrate 2 is an insulating substrate that electrically connects the piezoelectric vibrator 3 and the electronic component 4 with a wiring pattern and integrally forms them, and is made of a resin material. The substrate 2 is made of, for example, glass epoxy resin, which is an insulator that is easy to process, such as by cutting.

[0057] As shown in Figures 1 and 3, a piezoelectric vibrator 3 and an electronic component 4 are mounted on the top surface 2a of the substrate 2. The overlapping area where the top surface 2a of the substrate 2 and the piezoelectric vibrator 3 overlap is substantially rectangular in plan view. As shown in Figures 1, 3, and 10, first to fourth recesses 51a to 51d are formed in a substantially rectangular shape in plan view at each corner of the overlapping area on the top surface 2a so as to include the corner and its periphery. The first to fourth recesses 51a to 51d have a shape that allows the first to fourth external terminals 32a to 32d of the piezoelectric vibrator 3 to be disposed therein, and are recessed in a direction perpendicular to the top surface 2a.

[0058] As shown in FIG. 10 , first to fourth piezoelectric vibrator mounting pads 52a to 52d, each having a substantially rectangular shape in a plan view, are formed on the bottom surfaces of the first to fourth recesses 51a to 51d. In a plan view, there are gaps between the side surfaces of the first to fourth piezoelectric vibrator mounting pads 52a to 52d and the side surfaces of the first to fourth recesses 51a to 51d. The first to fourth piezoelectric vibrator mounting pads 52a to 52d are, for example, the following terminals: The first piezoelectric vibrator mounting pad 52a is a terminal connected to the first external terminal 32a, which is the input terminal of the piezoelectric vibrator 3; The second piezoelectric vibrator mounting pad 52b is a terminal connected to the second external terminal 32b, which is the output terminal of the piezoelectric vibrator 3; and the third and fourth piezoelectric vibrator mounting pads 52c and 52d are terminals connected to the third and fourth external terminals 32c and 32d, which are ground terminals of the piezoelectric vibrator 3. The first to third piezoelectric vibrator mounting pads 52a to 52c correspond to the "mounting pads" of the present invention.

[0059] The piezoelectric vibrator 3 is mounted on the upper surface 2a of the substrate 2 by joining the first to fourth external terminals 32a to 32d to the mounting surfaces of the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator using solder H (see Figure 3).

[0060] A fifth recess 51 e and a sixth recess 51 f are formed in a generally rectangular shape in plan view at each of two corners of the upper surface 2 a of the substrate 2 so as to include the corner and its periphery. The fifth recess 51 e and the sixth recess 51 f are recessed in a direction perpendicular to the upper surface 2 a.

[0061] The bottom surface of the fifth recess 51e is provided with first to third electronic component connection pads 53a to 53c, each having a substantially rectangular shape in plan view. The bottom surface of the sixth recess 51f is provided with fourth to sixth electronic component connection pads 53d to 53f, each having a substantially rectangular shape in plan view. The first to sixth electronic component connection pads 53a to 53f are, for example, the following terminals: the first electronic component connection pad 53a is a clock input terminal, the second electronic component connection pad 53b is a ground terminal, and the third electronic component connection pad 53c is an oscillation output terminal. The fourth electronic component connection pad 53d is a clock output terminal, the fifth electronic component connection pad 53e is an output enable terminal, and the sixth electronic component connection pad 53f is a power supply terminal. The first to sixth electronic component connection pads 53a to 53f are electrically connected to the first to sixth external terminals 4a to 4f of the electronic component 4 via wires.

[0062] A first wiring pattern 54a electrically connected to the second piezoelectric vibrator mounting pads 52b is formed on the upper surface 2a of the substrate 2. A second wiring pattern 54b electrically connected to the first piezoelectric vibrator mounting pads 52a is also formed on the upper surface 2a of the substrate 2. A third wiring pattern 54c electrically connecting the third piezoelectric vibrator mounting pads 52c and the fourth piezoelectric vibrator mounting pads 52d is also formed on the upper surface 2a of the substrate 2. A fourth wiring pattern 54d electrically connecting the second piezoelectric vibrator mounting pads 52b and the fourth electronic component connecting pads 53d is also formed on the upper surface 2a of the substrate 2. A fifth wiring pattern 54e electrically connecting the first piezoelectric vibrator mounting pads 52a and the first electronic component connecting pads 53a is also formed on the upper surface 2a of the substrate 2.

[0063] Furthermore, a sixth wiring pattern 54f is formed on the upper surface 2a of the substrate 2, electrically connecting the fourth piezoelectric vibrator mounting pad 52d and the second electronic component connecting pad 53b. A seventh wiring pattern 54g is formed on the upper surface 2a of the substrate 2, electrically connected to the fifth electronic component connecting pad 53e. An eighth wiring pattern 54h is formed on the upper surface 2a of the substrate 2, electrically connected to the sixth electronic component connecting pad 53f. A ninth wiring pattern 54i is formed on the upper surface 2a of the substrate 2, electrically connected to the third electronic component connecting pad 53c.

[0064] 2, first to fourth recesses 55a to 55d, each having a substantially rectangular shape, are formed at each corner of the lower surface 2b of the substrate 2 so as to include the corner and its periphery in a plan view. The first to fourth recesses 55a to 55d are recessed in a direction perpendicular to the lower surface 2b.

[0065] First to fourth external terminals 56a to 56d are formed on the bottom surfaces of the first to fourth recesses 55a to 55d. The first to fourth external terminals 56a to 56d are used when mounting the piezoelectric vibrating device 1 on another device (such as a substrate). The first to fourth external terminals 56a to 56d are, for example, the following terminals: the first external terminal 56a is a power supply terminal, the second external terminal 56b is a clock output terminal, the third external terminal 56c is a ground terminal, and the fourth external terminal 56d is an output enable terminal.

[0066] The first to fourth external terminals 56a to 56d are generally rectangular in plan view, with gaps between the side surfaces of the first to fourth external terminals 56a to 56d and the side surfaces of the first to fourth recesses 55a to 55d. However, the fourth external terminal 56d has a chamfered C-surface (cornered surface) that serves as an indicator for the mounting direction of the piezoelectric vibrating device 1. Note that this indicator is not limited to a chamfered C-surface (cornered surface), and may be, for example, a chamfered R-surface (rounded surface) or a protrusion.

[0067] A first wiring pattern 57a ​​electrically connected to the first external terminal 56a is formed on the lower surface 2b of the substrate 2, and the first wiring pattern 57a ​​extends to the side surface of the substrate 2. A second wiring pattern 57b electrically connected to the first external terminal 56a is formed on the lower surface 2b of the substrate 2. A third wiring pattern 57c electrically connected to the second external terminal 56b is formed on the lower surface 2b of the substrate 2, and the third wiring pattern 57c extends to the side surface of the substrate 2. A fourth wiring pattern 57d electrically connected to the second external terminal 56b is formed on the lower surface 2b of the substrate 2. A fifth wiring pattern 57e electrically connected to the third external terminal 56c is formed on the lower surface 2b of the substrate 2.

[0068] Furthermore, a sixth wiring pattern 57f electrically connected to the third external terminal 56c is formed on the lower surface 2b of the substrate 2, and the sixth wiring pattern 57f extends to the side surface of the substrate 2. Furthermore, a seventh wiring pattern 57g electrically connected to the fourth external terminal 56d and branching out, one of the branches extending to the side surface of the substrate 2, is formed on the lower surface 2b of the substrate 2. Furthermore, an eighth wiring pattern 57h is formed on the lower surface 2b of the substrate 2, one end of which extends to the side surface of the substrate 2. Furthermore, a ninth wiring pattern 57i is formed on the lower surface 2b of the substrate 2, one end of which extends to the side surface of the substrate 2.

[0069] The substrate 2 is formed with through holes 58a to 58f, each having a through portion penetrating from the upper surface 2a to the lower surface 2b of the substrate 2 and a through electrode formed on the inner wall surface of the through portion. The through electrode of the through hole 58a electrically connects the first wiring pattern 54a to the eighth wiring pattern 57h. The through electrode of the through hole 58b electrically connects the second wiring pattern 54b to the ninth wiring pattern 57i. The through electrode of the through hole 58c electrically connects the eighth wiring pattern 54h to the second wiring pattern 57b. The through electrode of the through hole 58d electrically connects the sixth wiring pattern 54f to the fifth wiring pattern 57e. The through electrode of the through hole 58e electrically connects the ninth wiring pattern 54i to the fourth wiring pattern 57d. The through electrode of the through hole 58f electrically connects the seventh wiring pattern 54g to the seventh wiring pattern 57g.

[0070] The first external terminal 56a is electrically connected to the sixth electronic component connecting pad 53f via the second wiring pattern 57b, through hole 58c, and eighth wiring pattern 54h. The second external terminal 56b is electrically connected to the third electronic component connecting pad 53c via the fourth wiring pattern 57d, through hole 58e, and ninth wiring pattern 54i. The third external terminal 56c is electrically connected to the fourth piezoelectric vibrator mounting pad 52d and the second electronic component connecting pad 53b via the fifth wiring pattern 57e, through hole 58d, and sixth wiring pattern 54f. The fourth external terminal 56d is electrically connected to the fifth electronic component connecting pad 53e via the seventh wiring pattern 57g, through hole 58f, and seventh wiring pattern 54g. The eighth wiring pattern 57h is electrically connected to the second piezoelectric vibrator mounting pad 52b via the through hole 58a and the first wiring pattern 54a. The ninth wiring pattern 57i is electrically connected to the first piezoelectric vibrator mounting pad 52a via a through hole 58b and the second wiring pattern 54b.

[0071] On the substrate 2, the various pads (first to fourth pads 52a to 52d for mounting piezoelectric vibrators, first to sixth pads 53a to 53f for connecting electronic components, etc.), external terminals (first to fourth external terminals 56a to 56d, etc.), and wiring patterns (first to ninth wiring patterns 54a to 54i, first to ninth wiring patterns 57a to 57i, etc.) are formed from Cu foil or the like, and the penetrating electrodes of the through holes (penetrating electrodes of through holes 58a to 58f, etc.) are formed from Cu plating or the like.

[0072] The sealing resin used for the resin molded portion 5 is a thermosetting resin such as epoxy resin, and as shown in Fig. 3, the resin molded portion 5 is molded onto the upper surface 2a side of the substrate 2 so as to cover the piezoelectric vibrator 3 and the electronic components 4. In a plan view, the periphery of the substrate 2 and the periphery of the resin molded portion 5 are substantially aligned.

[0073] Below, the positional relationship between the first to fourth external terminals 32a to 32d formed on the second main surface 302 of the second sealing member 30 of the piezoelectric vibrator 3 and the through holes 33a to 33c formed in the second sealing member 30, and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator formed on the upper surface 2a of the substrate 2 will be explained with reference to Figure 12.

[0074] In a planar view, the first to fourth external terminals 32a to 32d and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrators partially overlap each other, and the first to fourth external terminals 32a to 32d are positioned more inward than the first to fourth pads 52a to 52d for mounting the piezoelectric vibrators.

[0075] In a plan view, the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c are connected to the first to third external terminals 32a to 32c, and in this embodiment, are connected to the first regions 32a1 to 32c1 of the first to third external terminals 32a to 32c. As described above, the surfaces of the first regions 32a1 to 32d1 are Ti (titanium) metal layers, and the surfaces of the second regions 32a2 to 32d2 are Au (gold) metal layers, and the metal material on the surfaces of the first regions 32a1 to 32d1 is less wettable by solder H than the metal material on the surfaces of the second regions 32a2 to 32d2. The area of ​​the second regions 32a2 to 32d2 in a plan view is larger than the area of ​​the first regions 32a1 to 32d1 in a plan view. The first to third external terminals 32a to 32c are formed such that the second regions 32a2 to 32c2 are closer to the center points C2a to C2d of the first to third piezoelectric vibrator mounting pads 52a to 52c than the first regions 32a1 to 32c1 in a plan view. The center points C2a to C2c of the first to third piezoelectric vibrator mounting pads 52a to 52c correspond to the "approximate centers of the mounting pads" of the present invention.

[0076] In a plan view, a portion of the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap the first to third piezoelectric vibrator mounting pads 52a to 52c. In addition, in a plan view, the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap the line segments connecting the center points C2a to C2c of the first to third piezoelectric vibrator mounting pads 52a to 52c and the center points C1a to C1c of the first to third external terminals 32a to 32c.

[0077] According to the above-described embodiment, in a plan view, a portion of the penetration portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap with the first to third piezoelectric vibrator mounting pads 52a to 52c, so that the amount of solder H overlapping the penetration portions 33a1 to 33c1 of the through holes 33a to 33c and the amount of solder H near the penetration portions 33a1 to 33c1 can be reduced, and creeping up of the solder H into the penetration portions 33a1 to 33c1 of the through holes 33a to 33c can be suppressed. In addition, the penetration portions 33a1 to 33c1 of the through holes 33a to 33c (more specifically, the space inside the penetration electrodes 33a2 to 33c2) can be filled with the resin mold portion 5, which is further desirable for suppressing creeping up of the solder H into the penetration portions 33a1 to 33c1 of the through holes 33a to 33c.

[0078] Furthermore, the bulges of the solder H are largest at the center points C1a to C1d, which are approximately the centers of the first to fourth external terminals 32a to 32d, and at the center points C2a to C2d, which are approximately the centers of the first to fourth piezoelectric vibrator mounting pads 52a to 52d. Therefore, the positional relationship between the first to third external terminals 32a to 32d and the first to third piezoelectric vibrator mounting pads 52a to 52c and the through portions 33a1 to 33c1 is as follows: From the outside, by ensuring that the penetration portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap with the line segments connecting the center points C2a to C2c of the first to third pads 52a to 52c for mounting the piezoelectric vibrators and the center points C1a to C1c of the first to third external terminals 32a to 32c, where the amount of solder H is greatest, it is possible to prevent the solder H from creeping up into the penetration portions 33a1 to 33c1 of the through holes 33a to 33c.

[0079] Furthermore, when viewed in a plane, by making the metal material (Ti (titanium) in this embodiment) on the surface of the first regions 32a1 to 32c1 that are connected to the through portions 33a1 to 33c1 of the through holes 33a to 33c a material that is less wettable to solder H than the metal material (Au (gold) in this embodiment) of the second regions 32a2 to 32c2 that are not connected to the through portions 33a1 to 33c1 of the through holes 33a to 33c, the amount of solder H that overlaps with the through portions 33a1 to 33c1 of the through holes 33a to 33c can be reduced, and the solder H can be prevented from creeping up to the through portions 33a1 to 33c1 of the through holes 33a to 33c.

[0080] Furthermore, by making the area in a planar view of the second regions 32a2 to 32d2, whose surface metal material is more easily wetted by solder H, in the first external terminals 32a to 32d larger than the area in a planar view of the first regions 32a1 to 32d1, it is possible to increase the area of ​​the region where the second regions 32a2 to 32d2, whose surface metal material is more easily wetted by solder H in a planar view, overlap with the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator, thereby improving the electrical connection via solder H between the first to fourth external terminals 32a to 32d and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator.

[0081] Furthermore, by forming the first to fourth external terminals 32a to 32d so that the second regions 32a2 to 32d2, whose surface metal material is more easily wetted by solder H in a planar view, are closer to the center points C2a to C2d of the first to fourth pads 52a to 52d for mounting piezoelectric vibrators than the first regions 32a1 to 32d1, it is possible to increase the amount of solder H in the areas where the second regions 32a2 to 32d2, whose surface metal material is more easily wetted by solder H in a planar view, and the first to fourth pads 52a to 52d for mounting piezoelectric vibrators overlap, thereby improving the electrical connection via solder H between the first to fourth external terminals 32a to 32d and the first to fourth pads 52a to 52d for mounting piezoelectric vibrators.

[0082] In addition, various design modifications can be made to the above-described configuration within the scope of the claims.

[0083] For example, in the above embodiment, it was described that in a planar view, some areas of the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator, but this is not limited to this, and for example, as shown in Figure 13, all areas of the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c may not overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator. In this case, in a plan view, there are no areas in the penetration portions 33a1 to 33c1 of the through holes 33a to 33c that overlap with the first to third piezoelectric vibrator mounting pads 52a to 52c, so that it is possible to almost completely eliminate the solder H that overlaps with the penetration portions 33a1 to 33c1 of the through holes 33a to 33c in a plan view or the solder H near the penetration portions 33a1 to 33c1, thereby further suppressing the solder H from creeping up to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c. In addition, it is possible to fill the penetration portions 33a1 to 33c1 of the through holes 33a to 33c (more specifically, the space inside the penetration electrodes 33a2 to 33c2) with the resin mold portion 5, which is desirable to further suppress the solder H from creeping up to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c.

[0084] Furthermore, in the above embodiment, it has been described that in a planar view, some areas of the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c do not overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator, but this is not limited to this, and for example, as shown in Figure 14, all areas of the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c may overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator.

[0085] In the above embodiment, the first to fourth external terminals 32a to 32d are generally rectangular in plan view, and the first to fourth piezoelectric vibrator mounting pads 52a to 52d are generally rectangular in plan view. However, this is not limited to this. For example, the first to fourth external terminals 32a to 32d may be generally L-shaped, the first to fourth piezoelectric vibrator mounting pads 52a to 52d may be generally L-shaped, and the first to fourth L-shaped external terminals 32a to 32d may be generally L-shaped. to 32d are configured to include second regions 32a2 to 32d2 whose surface metal material is Au (gold), and first regions 32a1 to 32d1 whose surface metal material is Ti (titanium), which is less likely to be wetted by metal brazing filler metals such as solder than Au (gold), and the penetrating portions 33a1 to 33c1 of the through holes 33a to 33c may be connected to the first regions 32a1 to 32c1 of the first to third external terminals 32a to 32c.

[0086] Furthermore, in the above embodiment, it has been described that the objects that do not overlap at least partially with the first to third pads 52a to 52c for mounting the piezoelectric vibrator in a planar view are the penetration portions 33a1 to 33c1 of the through holes 33a to 33c formed in the second sealing member 30, but this is not limited to this, and for example, as shown in Figure 15, they may also be cutout portions formed in the second sealing member 30, an example of which is shown in Figure 15.

[0087] 15, instead of through holes 33a to 33c, castellations 33A to 33C are formed in second sealing member 30 from first main surface 301 to second main surface 302. Castellations 33A to 33C are formed to include notch portions 33A1 to 33C1 formed in the side surface of second sealing member 30 and notch electrodes 33A2 to 33C2 formed in the wall surfaces of notch portions 33A1 to 33C3. Notch portions 33A1, 33B1, and 33C1 correspond to the "communication portion" and "notch portion" of the present invention, and notch electrodes 33A2, 33B2, and 33C2 correspond to the "connection electrodes" of the present invention.

[0088] In a plan view, the cutout portions 33A1 to 33C1 of the castellations 33A to 33C are connected to the first external terminals 32a to 32c, and in this embodiment, are connected to the first regions 32a1 to 32c1 of the first external terminals 32a to 32c. In a plan view, some regions of the cutout portions 33A1 to 33C1 of the castellations 33A to 33C do not overlap the first to third piezoelectric vibrator mounting pads 52a to 52c. Furthermore, in a plan view, the cutout portions 33A1 to 33C1 of the castellations 33A to 33C do not overlap the line segments connecting the center points C2a to C2c of the first to third piezoelectric vibrator mounting pads 52a to 52c and the center points C1a to C1c of the first to third external terminals 32a to 32c.

[0089] The entire area of ​​the cutout portions 33A1 to 33C1 of the castellations 33A to 33C may not overlap with the first to third piezoelectric vibrator mounting pads 52a to 52c, or the entire area of ​​the cutout portions 33A1 to 33C1 of the castellations 33A to 33C may overlap with the first to third piezoelectric vibrator mounting pads 52a to 52c.

[0090] Furthermore, in the above embodiment, solder H is used as the bonding material for bonding the first to fourth external terminals 32a to 32d and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator, but this is not limited to this and, for example, a metal brazing material other than solder may also be used.

[0091] In the above embodiment, the first and second sealing members 20, 30 sandwiching the piezoelectric diaphragm 10, which is an AT-cut quartz plate, are AT-cut quartz plates, but this is not limited to this. For example, the first and second sealing members 20, 30 may be made of glass or a resin material. Furthermore, the substrate is not limited to one with a glass epoxy resin base material, and ceramic or the like may also be used.

[0092] In addition, in the above embodiment, the piezoelectric vibration plate 10 is an AT-cut quartz plate, but this is not limited to this and may be, for example, a Z-plate (tuning fork vibrating piece), an SC-cut quartz plate, etc.

[0093] Furthermore, in the above embodiment, a device in which the piezoelectric vibrator 3 and the electronic component 4 are covered by a resin molded portion 5 has been described, but the present invention can also be implemented in a similar manner in a device that is not molded with resin.

[0094] Furthermore, the contents described in the above embodiment and the contents described in the above modified examples may be combined as appropriate.

[0095] The present invention is widely applicable to piezoelectric vibration devices that include a substrate and a piezoelectric vibrator mounted on the mounting surface of the substrate.

[0096] 1: Piezoelectric vibration device 2: Substrate 3: Piezoelectric vibrator 5: Resin molded portion 10: Piezoelectric vibration plate 20: First sealing member 30: Second sealing member 32a to 32d: First to fourth external terminals 32a1 to 32c1: First region 32a2 to 32c2: Second region 33a to 33c: Through holes 33a1 to 33c1: Penetration portion 33a2 to 33c2: Penetration electrodes 52a to 52d: First to fourth pads for mounting piezoelectric vibrators 111, 112: First and second excitation electrodes C2a to C2c: Center points (approximate centers of mounting pads) H: Solder CD1, CD2: Conductive paths

Claims

1. A piezoelectric vibration device comprising: a piezoelectric diaphragm having electrodes formed thereon; and a pair of first and second sealing members that sandwich the piezoelectric diaphragm to hermetically seal the vibration portion of the piezoelectric diaphragm, a piezoelectric vibrator having external terminals formed on one main surface of the second sealing member opposite the piezoelectric diaphragm; a substrate having mounting pads on its mounting surface for mounting the piezoelectric vibrator; and a metal brazing material that bonds the external terminals to the mounting pads, wherein the second sealing member has a communication portion formed by a through portion or cutout portion that extends from the one main surface to the other main surface and connects to the external terminals formed on the other main surface, and a connection electrode that forms part of a conductive path that connects the external terminals and the electrodes is formed in the communication portion, wherein, in a plan view, the external terminals have a first region connected to the communication portion and a second region having a metal material composition different from that of the first region, and the metal material on the surface of the first region is less likely to be wetted by the metal brazing material than the metal material on the surface of the second region.

2. A piezoelectric vibration device as described in claim 1, further comprising a resin molded portion molded onto the mounting surface of the substrate so as to cover the piezoelectric vibrator mounted on the mounting surface of the substrate.

3. A piezoelectric vibration device as described in claim 1 or claim 2, characterized in that the area of ​​the second region in a planar view is larger than the area of ​​the first region in a planar view.

4. A piezoelectric vibration device as described in claim 1 or 2, characterized in that the external terminal is formed so that, in a planar view, the second region is closer to approximately the center of the mounting pad than the first region.