WO2025063008A1 - Piezoelectric resonator device - Google Patents

Abstract

The present invention prevents a bonding material that bonds external terminals of a piezoelectric resonator and a mounting pad of a substrate from spreading up to a communication part formed in a second sealing member.　This piezoelectric resonator device comprises: a piezoelectric resonator 3 including a piezoelectric resonator plate 10, and first and second sealing members 20, 30 that hermetically seal a vibrating part 11 of the piezoelectric resonator plate 10, the piezoelectric resonator 3 having a first external terminal 32a formed on a second main surface 302 of the second sealing member 30; a substrate 2 having a first pad 52a formed thereon for mounting the piezoelectric resonator 3; a solder H that bonds the first external terminal 32a and the first pad 52a; and a resin mold part 5 molded on the substrate 2 so as to cover the piezoelectric resonator 3. The second sealing member 30 has a penetrating part 33a1 continuous with the first external terminal 32a, and a through electrode 33a2 is formed in the penetrating part 33a1. The penetrating part 33a1 does not overlap with a line segment connecting a center point C2a of the first pad 52a and a center point C1a of the first external terminal 32a in a plan view.

Description

Piezoelectric Vibration Device

The present invention relates to a piezoelectric vibration device comprising a substrate and a piezoelectric vibrator mounted on the mounting surface of the substrate.

An example of a piezoelectric vibration device is the piezoelectric vibration device disclosed in Patent Document 1, which is as follows. The piezoelectric vibration device disclosed in Patent Document 1 comprises 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 (outer bottom surface) of the piezoelectric vibrator facing the substrate, and a plurality of mounting pads for the piezoelectric vibrator corresponding to the plurality of external connection terminals are formed on the mounting surface of the substrate. The multiple external connection terminals formed on the outer bottom surface of the piezoelectric vibrator are joined via solder to corresponding ones of the multiple mounting pads for the piezoelectric vibrator formed on the mounting surface of the substrate.

Furthermore, as a piezoelectric vibrator, there is a so-called sandwich structure piezoelectric vibrator, which is disclosed, for example, in Patent Document 2. The sandwich structure 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 the first sealing member and the piezoelectric diaphragm are joined together to provide an internal space in which the 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 the one main surface facing the piezoelectric diaphragm. A through electrode formed on the inner wall surface of the through portion that connects to the external terminal from one main surface to the other main surface of the second sealing member is used as part of the conductive path that electrically connects each of the first excitation electrode and the second excitation electrode of the piezoelectric diaphragm to the external terminal corresponding to the first excitation electrode and the second excitation electrode. 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.

　By the way, 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 the oscillator circuit and mounted on the mounting surface of a substrate using solder, with the piezoelectric vibrator and electronic components sealed in resin.

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

However, in the case of a sandwich-structure piezoelectric vibrator, when the piezoelectric vibrator device is soldered to an external circuit board or the like through a reflow furnace by reflow soldering or the like, the piezoelectric vibrator device is reheated. As a result, the solder that joins the external terminal of the piezoelectric vibrator built into the piezoelectric vibrator device to the piezoelectric vibration mounting pad of the board is also reheated and remelted. The remelted solder is likely to creep up. In particular, in the case of a piezoelectric vibrator covered with a resin molded part, since the piezoelectric vibrator is surrounded by the resin molded around it, there is no escape route other than the through-hole formed in the second sealing member, and there is a risk that the solder will creep up to the through-hole formed in the second sealing member and even to the sealing part where the piezoelectric diaphragm and the second sealing member are joined. In particular, the solder that creeps up to the through-hole will diffuse to the through-hole electrode, which may lead to a decrease in electrical connectivity between the electrodes (first excitation electrode, second excitation electrode, etc.) and the external terminals corresponding to the electrodes, vibration inhibition of the piezoelectric diaphragm, and poor airtightness due to corrosion of the metal material of the first sealing member and the second sealing member.

In view of the above problems, the present invention aims to provide a piezoelectric vibration device that can prevent creeping up into a connection formed by a penetration or notch formed in a second sealing member of a bonding material that bonds an external terminal of a piezoelectric vibrator to a mounting pad of a substrate.

In order to achieve the above-mentioned object, the piezoelectric vibration device of the present invention comprises a piezoelectric vibration plate having an electrode formed thereon, and a pair of first and second sealing members which sandwich the piezoelectric vibration plate to hermetically seal the vibration portion of the piezoelectric vibration plate, a piezoelectric vibrator having an external terminal formed on one main surface of the second sealing member opposite to the piezoelectric vibration plate, a substrate having a mounting pad formed on its mounting surface for mounting the piezoelectric vibrator, and a bonding material which bonds the external terminal and the mounting pad, wherein the second sealing member has a connecting portion formed by a through portion or 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, a connecting electrode is formed in the connecting portion and forms part of a conductive path connecting the external terminal and the electrode, and when viewed in a planar view, the connecting portion does not overlap with a line segment connecting approximately the center of the mounting pad and approximately the center of the external terminal.

With this configuration, by making the connection portion not overlap the line connecting the approximate center of the mounting pad, where the amount of bonding material is greater, and the approximate center of the external terminal, in a plan view, it is possible to prevent the bonding material from creeping up to the connection portion.

In this case, it is preferable to further provide 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.

The joining material may be a brazing metal material, and in a plan view, an overlapping region of the external terminal where the connection electrode and the external terminal overlap, and a surrounding region around the overlapping region may be formed of an electrode material that is not easily wetted by the brazing metal material.

With this configuration, in a plan view, the overlapping area where the connecting electrode of the external terminal and the external terminal overlap, and the surrounding area around the overlapping area, are made of an electrode material that is not easily wetted by the metal brazing material (a state in which the metal brazing material does not flow easily and does not blend well with the metal surface), so the flow of the metal brazing material around the overlapping area can be suppressed, further reducing the amount of metal brazing material used as a joining material near the connection part, and creeping up into the connection part of the metal brazing material used as a joining material can be further suppressed.

According to the present invention, by making the connection portion not overlap with the line segment connecting the center point of the mounting pad, where the amount of bonding material is greater, and the center point of the exterior, in a plan view, it is possible to prevent the bonding material from creeping up to the connection portion.

2 is a schematic plan view of the upper 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 lower surface side of the piezoelectric vibration device (substrate of FIG. 1) of FIG. 1 . 2 is a schematic cross-sectional view of the piezoelectric vibration device taken along line AA of FIG. 1 with sealing resin added. 2 is a schematic plan view of the upper surface side of the piezoelectric vibrator of FIG. 1 (the first main surface side of a first sealing member provided in the piezoelectric vibrator of FIG. 1 ). 2 is a schematic plan view of a second main surface side of a first sealing member included in the piezoelectric vibrator of FIG. 1 . 2 is a schematic plan view of a first main surface side of a piezoelectric diaphragm included in the piezoelectric vibrator of FIG. 1 . 2 is a schematic plan view of a second main surface side of a piezoelectric diaphragm included in the piezoelectric vibrator of FIG. 1 . 2 is a schematic plan view of a first main surface side of a second sealing member included in the piezoelectric vibrator of FIG. 1 . 2 is a schematic plan view of the lower surface side of the piezoelectric vibrator of FIG. 1 (the second main surface side of a second sealing member provided in the piezoelectric vibrator of FIG. 1 ). FIG. 2 is a schematic plan view of the upper surface (mounting surface) side of the substrate of FIG. 1. 2 is a schematic cross-sectional view of a through hole formed in a second sealing member included in the piezoelectric vibrator of FIG. 1 . 1. This figure is for explaining the positional relationship between the first to fourth external terminals of the second sealing member provided on the piezoelectric vibrator in Figure 1, three through holes formed in the second sealing member, and the first to fourth pads for mounting the piezoelectric vibrator formed on the upper surface of the substrate. 13 is a diagram for explaining the positional relationship between the first to fourth external terminals and through holes and the first to fourth pads for mounting a piezoelectric vibrator in the first modified example. FIG. 13 is a diagram for explaining the positional relationship between the first to fourth external terminals and through holes and the first to fourth pads for mounting a piezoelectric vibrator in the second modified example. FIG. 13 is a diagram for explaining the positional relationship between the first to fourth external terminals and castellations and the first to fourth pads for mounting a piezoelectric vibrator in the third modified example. FIG.

Below, a piezoelectric vibration device according to one embodiment of the present invention will be described with reference to Figures 1 to 12.

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 the 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.

As shown in FIG. 3, the piezoelectric vibrator 3 comprises a piezoelectric diaphragm (corresponding to the "piezoelectric diaphragm" of the present invention) 10, a first sealing member (corresponding to the "first sealing member" of the present invention) 20, and a second sealing member (corresponding to the "second sealing member" of the present invention) 30. In the piezoelectric vibrator 3, the piezoelectric diaphragm 10 and the first sealing member 20 are bonded together, and the piezoelectric vibrator 3 and the second sealing member 30 are bonded together to form a package with a substantially rectangular sandwich structure. That is, in the piezoelectric vibrator 3, the first sealing member 20 and the second sealing member 30 are bonded to each of the two main surfaces of the piezoelectric diaphragm 10 to form an internal space (cavity) of the package, and the vibration part 11 (see FIG. 6 and FIG. 7) is hermetically sealed in this internal space.

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

Next, the piezoelectric vibration plate 10, the first sealing member 20, and the second sealing member 30 that constitute the piezoelectric vibrator 3 will be described with reference to Figs. 3 to 9. Note that the description here focuses on each component that is constructed as a single unit without being joined. Figs. 4 to 9 merely show examples of the configuration of the piezoelectric vibration plate 10, the first sealing member 20, and the second sealing member 30, respectively, and do not limit the present invention.

First, we will explain the piezoelectric diaphragm 10 with reference to Figures 6 and 7.

The piezoelectric diaphragm 10 is a piezoelectric substrate made of quartz, and both of its main surfaces (first main surface 101 and second main surface 102) are formed as flat and smooth surfaces (mirror finish). In this embodiment, an AT-cut quartz 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 of the 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 direction (short side direction) of the piezoelectric diaphragm 10 is the X-axis direction, and the direction parallel to the long side direction (long side direction) of the piezoelectric diaphragm 10 is the Z'-axis direction. The AT cut is a processing technique in which the three crystal axes of artificial quartz, the electrical axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis), are cut at an angle of 35°15' around the X-axis with respect to the Z-axis. In an AT-cut quartz plate, the X-axis coincides with the crystal axis of the quartz. The Y'-axis and Z'-axis coincide with axes that are inclined at approximately 35°15' from the Y-axis and Z-axis of the quartz crystal, respectively (this cutting angle may be changed somewhat within the range of adjusting the frequency-temperature characteristics of the AT-cut quartz plate). The Y'-axis and Z'-axis directions correspond to the cutting direction when cutting out the AT-cut quartz plate.

The piezoelectric vibration plate 10 has a vibration part 11 formed in a substantially rectangular shape, an outer frame part 12 that is thicker than the vibration part 11 and surrounds the outer periphery of the vibration part 11 with a gap therebetween, and a holding part 13 that holds the vibration part 11 by connecting the vibration part 11 and the outer frame part 12. That is, the piezoelectric vibration plate 10 is configured such that the vibration part 11, the outer frame part 12, and the holding part 13 are integrally provided. The holding part 13 extends (protrudes) from only one corner of the vibration part 11 located in the +X direction and the -Z' direction to the outer frame part 12 in the -Z' direction. Then, a cutout part 10a formed by cutting out the piezoelectric vibration plate 10 is provided between the vibration part 11 and the outer frame part 12. In this embodiment, the piezoelectric vibration plate 10 has only one holding part 13 that connects the vibration part 11 and the outer frame part 12, and the cutout part 10a is formed continuously so as to surround the outer periphery of the vibration part 11. In this embodiment, the outer frame portion 12 of the piezoelectric diaphragm 10 is configured without through holes or castellations. The piezoelectric diaphragm 10 is configured without any through-holes other than the cutout portion 10a.

A rectangular first excitation electrode 111 is formed on the vibration 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 vibration 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 a rectangular shape, and may be, for example, a diamond shape or an ellipse shape. The first excitation electrode 111 and the second excitation electrode 112 are not limited to the same shape, and may be different shapes, for example, the first excitation electrode 111 is rectangular and the second excitation electrode 112 is diamond shaped.

A first lead-out 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. 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-out 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 the holding portion 13 of the first main surface 101 of the piezoelectric diaphragm 10. 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.

A second lead-out 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 formed on the outer frame portion 12 of the second main surface 102 of the piezoelectric diaphragm 10. The second lead-out wiring 114 is led out 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 of the second main surface 102 of the piezoelectric diaphragm 10. Connection bonding patterns 12e and 12f are formed on the outer frame portion 12 of the second main surface 102 of the piezoelectric diaphragm 10.

In addition, an 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 -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 along a direction other than the X-axis direction of the AT cut, so that even if an inclined surface is formed in the wet etching process, parts other than acute angles also appear, reducing the risk of disconnection, etc.

The first main surface 101 of the piezoelectric diaphragm 10 is provided with a diaphragm-side first bonding pattern 121 as a vibration-side sealing part for bonding the piezoelectric diaphragm 10 to the first sealing member 20. The diaphragm-side first bonding pattern 121 is formed in a ring shape in a plan view on the outer frame part 12 of the first main surface 101 of the piezoelectric diaphragm 10. The outer peripheral edge of the diaphragm-side first bonding pattern 121 is provided close to the outer peripheral edge of the first main surface 101 of the piezoelectric diaphragm 10 (outer frame part 12). The diaphragm-side first bonding pattern 121 is electrically connected to a third external terminal 32 as a ground terminal described later, and acts as an earth electrode.

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

Furthermore, internal wiring 17 is formed on the inner wall surface of the outer frame portion 12 of the piezoelectric diaphragm 10. The first diaphragm-side bonding pattern 121 and the second diaphragm-side 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 is 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.

Next, the first sealing member 20 will be described with reference to Figures 4 and 5.

The first sealing member 20 is a substantially rectangular parallelepiped substrate formed from a single AT-cut quartz plate, and the second main surface 202 (the surface to be bonded to the piezoelectric diaphragm 10) of the first sealing member 20 is formed as a flat and smooth surface (mirror finish). Although the first sealing member 20 does not have a vibrating portion, by using an AT-cut quartz plate like the piezoelectric diaphragm 10, the thermal expansion coefficients of the piezoelectric diaphragm 10 and the first sealing member 20 can be made the same, and thermal deformation in the piezoelectric vibrator 3 can be suppressed. In addition, the directions of the X-axis, Y'-axis, and Z'-axis in the first sealing member 20 are also the same as those of the piezoelectric diaphragm 10. In this embodiment, the first sealing member 20 is configured without through holes or castellations, so that the manufacturing process of the first sealing member 20 can be significantly shortened. In addition, the first sealing member 20 has an improved corrosion resistance by eliminating the path for moisture to enter the internal space of the package.

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

The second main surface 202 of the first sealing member 20 is provided with a sealing member-side first bonding pattern 24 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 an overlapping position.

The second main surface 202 of the first sealing member 20 has connection bonding patterns 22a, 22b, and 22c formed thereon for bonding 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.

Finally, we will explain the second sealing member 30 with reference to Figures 8 and 9.

The second sealing member 30 is a roughly rectangular parallelepiped substrate made from an AT-cut quartz plate, and the first main surface 301 (the surface that is bonded to the piezoelectric diaphragm 10) of this second sealing member 30 is formed as a flat, smooth surface (mirror finish). Note that it is preferable that the second sealing member 30 also uses an AT-cut quartz plate like the piezoelectric diaphragm 10, and that the orientation of the X-axis, Y'-axis, and Z'-axis are the same as those of the piezoelectric diaphragm 10.

The first main surface (corresponding to the "first main surface" of the present invention) 301 of the second sealing member 30 is provided with a sealing member-side second bonding pattern 31 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, these patterns are provided at a position where 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 overlap.

The first main surface 301 of the second sealing member 30 has connection bonding patterns 34a, 34b, and 34c formed thereon to bond with 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. 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.

4. The second main surface 302 of the second sealing member 30 (corresponding to the "other main surface" of the present invention) is provided with the first to fourth external terminals 32a to 32d. 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 (corners) 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 of the mounting direction of the piezoelectric vibrator 3. Note that the indicator is not limited to the chamfering of the 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 at positions that overlap the outer frame portion 12 of the piezoelectric vibration plate 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.

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 configuration of the metal material in the first region 32a1 to 32d1 is different from the configuration of the metal material in the second region 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 surrounding regions around the overlapping regions. In 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.

The second sealing member 30 has three through holes 33a, 33b, and 33c that penetrate the first main surface 301 and the second main surface 302. The through holes 33a and 33b are configured to include a penetration portion 33a1 and 33b1 that penetrate the second sealing member 30, and a penetration electrode 33a2 and 33b2 that are formed along the inner wall surface of the penetration portion 33a1 and 33b1 to provide 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 to provide 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 penetrating 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 through electrode 33a2 form a conductive path CD1 that 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 through electrode 33b2 form a conductive path CD2 that connects the second excitation electrode 112 and the first external terminal 32b. The through portions 33a1, 33b1, and 33c1 correspond to the "communication portion" and "through portion" of the present invention, and the through electrodes 33a2, 33b2, and 33c2 correspond to the "connection electrodes" of the present invention that constitute a part of the conductive paths CD1 and CD2. Details of through holes 33a, 33b, and 33c will be described later.

Through holes 33a, 33b, 33c (penetration portions 33a1, 33b1, 33c1 of through holes 33a, 33b, 33c) are connected to first regions 32a1, 32b1, 32c1 of first to third external terminals 32a, 32b, 32c.

In the piezoelectric vibrator 3 including the piezoelectric diaphragm 10, first sealing member 20, and second sealing member 30 configured as 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, to manufacture 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.

At this time, the connection bonding patterns 22a, 22b, 22c formed on the second main surface 202 of the first sealing member 20 described above and the connection bonding patterns 12a, 12b, 12c formed on the first main surface 101 of the piezoelectric diaphragm 10 are diffusion bonded in a superimposed state, and the connection bonding patterns 12d, 12e, 12f formed on the second main surface 102 of the piezoelectric diaphragm 10 and the connection bonding patterns 34a, 34b, 34c formed on the first main surface 301 of the second sealing member 30 are diffusion bonded in a superimposed state. As a result, electrical conduction is obtained between the first excitation electrode 111 and the first external terminal 32a, and electrical conduction is obtained 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 through the first lead 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 this order. The second excitation electrode 112 is connected to the second external terminal 32b through the second lead 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 this order.

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 diaphragm side, the internal wiring 17, the first bonding pattern 121 on the diaphragm side, and the first bonding pattern 24 on the sealing member side.

In the piezoelectric vibrator 3, the various bonding patterns (first bonding pattern 24 on the sealing member side, connection bonding patterns 22a, 22b, 22c, first bonding pattern 121 on the vibration plate side, connection bonding patterns 12a, 12b, 12c, second bonding pattern 122 on the vibration plate side, connection bonding patterns 12d, 12e, 12f, second bonding pattern 31 on the sealing member side, 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, with a Ti (titanium) metal layer and an Au (gold) metal layer being formed in that order from the bottom layer side by vapor deposition or sputtering. In addition, the electrodes (first excitation electrode 111, second excitation electrode 112), wiring (first lead-out wiring 113, second lead-out wiring 114, internal wiring 12g, 17, etc.), and parts 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.

The remaining parts 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 the Ti (titanium) metal layer on the quartz plate.

As described above, the first regions 32a1-32d1 consist only of a Ti (titanium) metal layer on the quartz plate, and the second regions 32a2-32d2 consist of a Ti (titanium) metal layer and an Au (gold) metal layer laminated in this order on the quartz plate from the quartz plate side. In this way, the Ti (titanium) on the surfaces of the first regions 32a1-32d1 is an electrode material that is not easily wetted by a metal brazing material such as solder H, and the Au (gold) on the surfaces of the second regions 32a2-32d2 is an electrode material that is easily wetted by a metal brazing material such as solder H. In other words, the metal material on the surfaces of the first regions 32a1-32d1 is less easily wetted by a metal brazing material such as solder H than the metal material on the surfaces of the second regions 32a2-32d2.

As shown in FIG. 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 its diameter 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.

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 vibration plate 10 is formed in a ring shape in a plan view. The seal path 15 is formed by diffusion bonding (Au-Au bonding) between the vibration plate side first bonding pattern 121 and the sealing member side first bonding pattern 24 described above. 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 arranged close to the outer periphery of the package. Similarly, the seal path 16 is formed by diffusion bonding (Au-Au bonding) between the vibration plate side second bonding pattern 122 and the sealing member side second bonding pattern 31 described above. 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 arranged close to the outer periphery of the package. The seal paths 15 and 16 are not electrically connected to the electrical conduction path between the first and second excitation electrodes 111 and 112 and the first and second external terminals 32a and 32b. 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 32c, etc.) via the penetrating electrode 33c2 of the through hole 33c.

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 vibration plate 10 have a gap of 1.00 μm or less, and the second sealing member 30 and the piezoelectric vibration plate 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 vibration plate 10 is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au-Au bonding of this embodiment), and the thickness of the seal path 16 between the second sealing member 30 and the piezoelectric vibration plate 10 is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au-Au bonding of this embodiment). As a comparative example, the thickness of a conventional metal paste sealing material using Sn is 5 μm to 20 μm. As a comparative example, the thickness of a sealing material made of a brazing material using an AuSn alloy is 5 μm to 20 μm.

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

As shown in FIG. 1, the first to sixth external terminals 4a to 4f, which are substantially rectangular in 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 the first to sixth pads 53a to 53f for connecting electronic components, which are formed on the top surface 2a of the substrate 2.

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

As shown in Figs. 1 and 3, a piezoelectric vibrator 3 and electronic components 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 approximately rectangular in plan view. As shown in Figs. 1, 3 and 10, first to fourth recesses 51a to 51d are formed in approximately rectangular shapes in plan view at each corner of the overlapping area on the top surface 2a in plan view, so as to include the corner and its periphery. The first to fourth recesses 51a to 51d are shaped so that the first to fourth external terminals 32a to 32d of the piezoelectric vibrator 3 can be placed therein, and are recessed in a direction perpendicular to the top surface 2a.

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

The piezoelectric vibrator 3 is mounted on the upper surface 2a of the substrate 2 by bonding 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).

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

The first to third electronic component connecting pads 53a to 53c, which are generally rectangular in plan view, are formed on the bottom surface of the fifth recess 51e, and the fourth to sixth electronic component connecting pads 53d to 53f, which are generally rectangular in plan view, are formed on the bottom surface of the sixth recess 51f. The first to sixth electronic component connecting pads 53a to 53f are, for example, the following terminals. The first electronic component connecting pad 53a is a clock input terminal, the second electronic component connecting pad 53b is a ground terminal, and the third electronic component connecting pad 53c is an oscillation output terminal. The fourth electronic component connecting pad 53d is a clock output terminal, the fifth electronic component connecting pad 53e is an output enable terminal, and the sixth electronic component connecting pad 53f is a power supply terminal. The first to sixth external terminals 4a to 4f of the electronic component 4 are electrically connected to the first to sixth pads 53a to 53f for connecting electronic components by wires.

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

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

As shown in FIG. 2, first to fourth recesses 55a to 55d are formed on the lower surface 2b of the substrate 2, each of which has a substantially rectangular shape in a plan view at each corner of the lower surface 2b, so as to include the corner and its periphery. The first to fourth recesses 55a to 55d are recessed in a direction perpendicular to the lower surface 2b.

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 vibration device 1 on other equipment (such as a board). 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.

The first to fourth external terminals 56a to 56d are generally rectangular in plan view, and there are 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-face (corner surface) that serves as an indicator for the mounting direction of the piezoelectric vibration device 1. Note that this indicator is not limited to a chamfered C-face (corner surface), and may be, for example, a chamfered R-face (rounded surface) or a protrusion.

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 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 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.

A sixth wiring pattern 57f is formed on the lower surface 2b of the substrate 2 and is electrically connected to the third external terminal 56c, and the sixth wiring pattern 57f extends to the side surface of the substrate 2. A seventh wiring pattern 57g is formed on the lower surface 2b of the substrate 2 and is electrically connected to the fourth external terminal 56d, and branches out, one of whose branches extends to the side surface of the substrate 2. 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. 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.

The substrate 2 is provided with through holes 58a-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.

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

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

The sealing resin used in 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 on 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 approximately aligned.

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 described with reference to FIG. 12.

In a plan view, the first to fourth external terminals 32a to 32d and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator 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 vibrator.

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 likely to be wetted 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. Additionally, 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.

In plan view, some areas of the penetration 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. In addition, in plan view, 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 vibrator and the center points C1a to C1c of the first to third external terminals 32a to 32c. Note that the center points C1a to C1c of the first to third external terminals 32a to 32c correspond to the "approximate centers of the external terminals" of the present invention, and the center points C2a to C2c of the first to third pads 52a to 52c for mounting the piezoelectric vibrator correspond to the "approximate centers of the mounting pads" of the present invention.

In the above 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 pads 52a to 52c for mounting the piezoelectric vibrator. This reduces the amount of solder H that overlaps with the penetration portions 33a1 to 33c1 of the through holes 33a to 33c in a plan view and the amount of solder H near the penetration portions 33a1 to 33c1, and thus prevents the solder H from creeping up to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c. 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 desirable for further preventing the solder H from creeping up to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c.

In addition, the bulge of the solder H is greatest 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 pads 52a to 52d for mounting the piezoelectric vibrator. Therefore, the positional relationship between the first to third external terminals 32a to 32 and the first to third pads 52a to 52c for mounting the piezoelectric vibrator, and the through-holes 33a1 to 33c1 is In plan view, the penetration portions 33a1-33c1 of the through holes 33a-33c are arranged not to overlap with the line segment connecting the center points C2a-C2c of the first to third piezoelectric vibrator mounting pads 52a-52c, where the amount of solder H is greatest, and the center points C1a-C1c of the first to third external terminals 32a-32c, thereby preventing the solder H from creeping up into the penetration portions 33a1-33c1 of the through holes 33a-33c.

In addition, by making the metal material (Ti (titanium) in this embodiment) of the surface of the first regions 32a1 to 32c1 that are connected to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c less wettable with solder H than the metal material (Au (gold) in this embodiment) of the second regions 32a2 to 32c2 that are not connected to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c in a plan view, it is possible to reduce the amount of solder H that overlaps with the penetration portions 33a1 to 33c1 of the through holes 33a to 33c, and to suppress the solder H from creeping up to the penetration portions 33a1 to 33c1 of the through holes 33a to 33c.

In addition, by making the area in plan 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 plan 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 plan 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.

In addition, 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 plan view, are closer to the center points C2a to C2d of the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator than the first regions 32a1 to 32d1, it is possible to increase the amount of solder H in the region where the second regions 32a2 to 32d2, whose surface metal material is more easily wetted by solder H in a plan view, and the first to fourth pads 52a to 52d for mounting the piezoelectric vibrator 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 the piezoelectric vibrator.

In addition, various design modifications can be made to the above-mentioned configuration within the scope of the matters described in the claims.

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, the through-holes 33a to 33c have no areas that overlap with the first to third piezoelectric vibrator mounting pads 52a to 52c in the through-holes 33a to 33c, so that the solder H that overlaps with the through-holes 33a1 to 33c1 in the through-holes 33a to 33c and the solder H near the through-holes 33a1 to 33c1 in the plan view can be almost completely eliminated, and the solder H can be further prevented from creeping up to the through-holes 33a1 to 33c1 of the through-holes 33a to 33c. In addition, the through-holes 33a1 to 33c1 of the through-holes 33a to 33c (more specifically, the space inside the through-hole electrodes 33a2 to 33c2) can be filled with the resin molded part 5, which is desirable for further preventing the solder H from creeping up to the through-holes 33a1 to 33c1 of the through-holes 33a to 33c.

In addition, in the above embodiment, it has been described that in a plan view, some areas of the penetration 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. However, this is not limited to this, and for example, as shown in FIG. 14, all areas of the penetration 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.

In addition, in the above embodiment, 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 plan view are described as 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 thereto, and may be, for example, notches formed in the second sealing member 30 as shown in FIG. 15, an example of which is shown in FIG. 15.

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

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 with the first to third pads 52a to 52c for mounting the piezoelectric vibrator. In addition, in a plan view, the cutout portions 33A1 to 33C1 of the castellations 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 vibrator and the center points C1a to C1c of the first to third external terminals 32a to 32c.

It is also possible to arrange so that the entire area of the cutout portions 33A1 to 33C1 of the castellations 33A to 33C does not overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator. It is also possible to arrange so that the entire area of the cutout portions 33A1 to 33C1 of the castellations 33A to 33C overlap with the first to third pads 52a to 52c for mounting the piezoelectric vibrator.

In addition, 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 may be, for example, a metal brazing material other than solder or a conductive resin adhesive. Furthermore, the substrate is not limited to one with a glass epoxy resin base material and may be ceramic or the like.

In addition, in the above embodiment, the first and second sealing members 20, 30 that sandwich the piezoelectric diaphragm 10, which is an AT-cut quartz plate, are AT-cut quartz plates, but this is not limited to this, and for example, the first and second sealing members 20, 30 may be made of glass or a resin material.

In addition, in the above embodiment, the piezoelectric diaphragm 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.

In the above embodiment, a device in which the piezoelectric vibrator 3 and electronic components 4 are covered with a resin molded portion 5 has been described, but the present invention can be similarly implemented in devices that are not molded with resin.

Furthermore, the contents described in the above embodiment and the contents described in the above modified example may be combined as appropriate.

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.

1: Piezoelectric vibration device 2: Substrate 3: Piezoelectric vibrator 5: Resin molded part 10: Piezoelectric vibration plate 20: First sealing member 30: Second sealing member 32a-32d: First to fourth external terminals 33a-33c: Through holes 33a1-33c1: Penetrating parts 33a2-33c2: Penetrating electrodes 52a-52d: First to fourth pads 111, 112 for mounting piezoelectric vibrators: First and second excitation electrodes C1a-C1c: Center point (approximate center of external terminals)
C2a to C2c: Center points (approximate centers of mounting pads)
H: solder CD1, CD2: conductive path

Claims (3)

a piezoelectric vibrator including a piezoelectric diaphragm having electrodes formed thereon, and a pair of first and second sealing members sandwiching the piezoelectric diaphragm to hermetically seal a vibration portion of the piezoelectric diaphragm, the second sealing member having one main surface facing the piezoelectric diaphragm and another main surface opposite the piezoelectric diaphragm, the second sealing member having an external terminal formed thereon;
a substrate having a mounting pad on a mounting surface on which the piezoelectric vibrator is mounted;
a bonding material that bonds the external terminal and the mounting pad,
the second sealing 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 connected to the external terminal formed on the other main surface,
a connection electrode that forms a part of a conductive path that electrically connects the external terminal and the electrode is formed in the communication portion;
A piezoelectric vibration device, characterized in that, in a plan view, the connection portion does not overlap with a line segment connecting approximately the center of the mounting pad and the center of the external terminal. The piezoelectric vibration device according to 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. The joining material is a brazing metal material,
The piezoelectric vibration device of claim 1 or 2, characterized in that, when viewed in a plane, an overlapping area of the external terminal where the connection electrode and the external terminal overlap, and a surrounding area around the overlapping area, are formed from an electrode material that is not easily wetted by the metal brazing material.

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