JP2010178092A - Piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric device capable of being miniaturized and improving mechanical strength. <P>SOLUTION: The piezoelectric device 1 includes a package 3 housing a piezoelectric body element 2, a mounting board 4 for supporting the package 3 through a column member 51, and an electronic component 6 provided on the mounting board 4 so as to be positioned in a gap between the package 3 and the mounting board 4 formed of the column member 51 for driving the piezoelectric body element 2. The column member 51 has a recessed part 512 formed on an upper end face 511 at the side of the package 3, and the column member 51 and the package 3 are bonded with solder accumulated in the recessed part 512. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric device.

As a piezoelectric device, an electronic component constituting a crystal oscillator circuit is provided on a support substrate, and the crystal resonator is fixed to the support substrate via a spacer so that the crystal resonator is positioned above the electronic component. The thing of a structure is known (refer patent document 1).
A piezoelectric device (quartz oscillator) described in Patent Literature 1 includes a container body in which a crystal resonator element is mounted, a mounting base on which the container body is placed and fixed via four spacers, and the container body and the mounting And an IC element mounted on the mounting substrate so as to be positioned between the mounting substrates. In addition, a bonding electrode for electrically connecting the crystal resonator and the IC element through the spacer is provided at a portion that contacts the spacer of the container body. The bonding electrode is connected to the spacer through the solder. It is joined to.

  However, in the piezoelectric device (quartz oscillator) described in Patent Document 1, since solder is applied to the upper end surface constituted by the flat surface of the spacer, the spacer and the bonding electrode are pressed to bond them together. However, a solder fillet (for example, a lump of solder formed so as to cover the boundary between the spacer and the bonding electrode) cannot be formed. For this reason, the bonding strength between the spacer and the bonding electrode is insufficient (that is, the mechanical strength of the crystal unit is insufficient).

If soldering is performed from the outside so as to cover (close) these boundary portions in a state where the spacer and the bonding electrode are in contact with each other, the above-described fillet can be formed. A space for forming the fillet is required, which leads to an increase in the size of the crystal oscillator. In addition, depending on the shape of the bonding electrode (particularly the shape and area of the portion exposed from the spacer), the fillet is formed biased toward the side surface of the spacer or the bonding electrode. In this case, the spacer and the bonding electrode The joint strength is insufficient.
Thus, the piezoelectric device (quartz oscillator) of Patent Document 1 has a problem that it is impossible to achieve both reduction in size and improvement in mechanical strength.

Japanese Patent Laying-Open No. 2005-210673

  An object of the present invention is to provide a piezoelectric device that can be reduced in size and improved in mechanical strength.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
[Application Example 1]
A package containing a piezoelectric element;
A mounting substrate that supports the package;
A spacer provided between the package and the mounting substrate, and forming a gap between the package and the mounting substrate;
An electronic component disposed in the gap and for driving the piezoelectric element;
The spacer has a recess that opens to the end surface on the package side,
The said spacer and the said package are joined by the brazing | wax material stored in the said recessed part, The piezoelectric device characterized by the above-mentioned.
Accordingly, it is possible to provide a piezoelectric device that can be reduced in size and improved in mechanical strength.

[Application Example 2]
The piezoelectric device according to Application Example 1, wherein a fillet is formed inside the recess.
Accordingly, the bonding strength between the spacer and the package can be increased, and the piezoelectric device can be miniaturized and the degree of design freedom can be improved.
[Application Example 3]
The piezoelectric device according to Application Example 2, wherein the fillet is formed in an arch shape that connects a pair of opposing side surfaces of the recess.
Thereby, the joint strength between the spacer and the package can be further increased.

[Application Example 4]
The spacer has a columnar shape,
4. The piezoelectric device according to any one of application examples 1 to 3, wherein the concave portion has a concave line whose both ends are open to a side surface of the spacer.
Thereby, the fillet formed in the recess can be visually recognized from the outside of the spacer. As a result, the joining state between the spacer and the package can be easily confirmed.

[Application Example 5]
The piezoelectric device according to Application Example 4, wherein the recess includes a plurality of the recesses, and at least two of the recesses intersect each other.
Thereby, since the area | region which can form a fillet can be ensured large in a concave strip, the joining strength of a spacer and a package can be raised more.

[Application Example 6]
The electronic component is mounted on the mounting board,
The piezoelectric device according to any one of Application Examples 1 to 5, wherein the spacer has conductivity, and electrically connects the piezoelectric element and the electronic component.
Thereby, the number of parts of the piezoelectric device can be reduced, and the manufacture of the piezoelectric device can be simplified, the cost can be reduced, and the size can be reduced.

[Application Example 7]
7. The piezoelectric device according to any one of application examples 1 to 6, wherein an end surface of the spacer on the package side is configured by a curved convex surface.
Thereby, a fillet is formed in the recess, and a fillet is also formed between the end surface of the spacer on the package side and the package. As a result, the bonding strength between the spacer and the package can be further increased.

It is sectional drawing which shows 1st Embodiment of the piezoelectric device of this invention. FIG. 2 is a top view and a bottom view of a package included in the piezoelectric device shown in FIG. 1. It is a top view of the mounting substrate with which the piezoelectric device shown in FIG. 1 is provided. It is a perspective view of the pillar member with which the piezoelectric device shown in FIG. 1 is provided. It is the elements on larger scale for demonstrating the joining method of the column member shown in FIG. It is the elements on larger scale for demonstrating the joining method of the column member shown in FIG. It is sectional drawing which shows the state which molded the piezoelectric device shown in FIG. It is a perspective view which shows the pillar member with which the piezoelectric device which concerns on 2nd Embodiment of this invention is provided. It is the top view and sectional drawing which show the pillar member with which the piezoelectric device which concerns on 3rd Embodiment of this invention is provided. It is a figure which shows the joining state of the pillar member shown in FIG. 9, and a package. It is a perspective view which shows the pillar member with which the piezoelectric device which concerns on 4th Embodiment of this invention is provided. It is a figure which shows the joining state of the pillar member shown in FIG. 11, and a package.

Hereinafter, a piezoelectric device of the present invention will be described in detail based on embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a cross-sectional view showing a first embodiment of the piezoelectric device of the present invention, FIG. 2 is a top view and a bottom view of a package included in the piezoelectric device shown in FIG. 1, and FIG. 3 is a diagram of the piezoelectric device shown in FIG. FIG. 4 is a perspective view of a column member included in the piezoelectric device shown in FIG. 1, and FIGS. 5 and 6 are partially enlarged views for explaining a method of joining the column members shown in FIG. FIGS. 7 and 7 are cross-sectional views showing a state where the piezoelectric device shown in FIG. 1 is molded. In FIG. 3, the wiring pattern 42 described later is not shown. 1 and FIGS. 4 to 7, the upper side is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.
The piezoelectric device 1 shown in FIG. 1 mounts (fixes and supports) the package 3 via a package (accommodating portion) 3 that accommodates the piezoelectric element 2 and four column members (spacers) 51, 52, 53, and 54. And the electronic component 6 mounted on the mounting substrate 4 so as to be positioned between the package 3 and the mounting substrate 4.

Hereinafter, these will be described in detail in order.
First, the piezoelectric element 2 will be described.
In the present embodiment, the piezoelectric element 2 is a surface acoustic wave element (SAW chip). As shown in FIG. 2, the surface acoustic wave element 2 includes a piezoelectric substrate 21 having a longitudinal shape, an IDT (comb electrode) 22 provided on the piezoelectric substrate 21, and a pair disposed on both sides of the IDT 22. Reflectors 23a and 23b.

The piezoelectric substrate 21 is made of quartz. Note that the piezoelectric substrate 21 may be made of a piezoelectric material other than quartz, such as lithium tantalate, lithium niobate, and lithium borate.
The IDT 22 is provided at the center of the piezoelectric substrate 21. The IDT 22 includes a pair of electrodes 22a and 22b. The pair of electrodes 22a and 22b are arranged so that the electrode finger 221a of the electrode 22a and the electrode finger 221b of the electrode 22b are engaged with each other. When a voltage is applied between the pair of electrodes 22a and 22b, periodic distortion occurs between the electrode fingers 221a and 221b due to the piezoelectric effect of the piezoelectric substrate 21, and the surface acoustic wave is excited. The excited surface acoustic wave propagates along the continuous direction of the electrode fingers 221a and 221b (that is, the longitudinal direction of the piezoelectric substrate 21).
The pair of reflectors 23a and 23b are arranged on both sides of the IDT 22 in the above-described propagation direction of the surface acoustic wave. Such reflectors 23a and 23b have a function of reflecting the surface acoustic wave propagating to the piezoelectric substrate 21 and confining it between the reflectors 23a and 23b.

  The IDT 22 and the reflectors 23a and 23b are formed so as to be shifted to one end side in the longitudinal direction of the piezoelectric substrate 21 (right end side in FIG. 2). A pair of extraction electrodes 24 a and 24 b are formed on the other end side (left end side in FIG. 2) of the piezoelectric substrate 21. The extraction electrodes 24a and 24b are each formed so as to go from the upper surface (the surface on which the IDT 22 is formed) of the piezoelectric substrate 21 to the lower surface via the side surface. The extraction electrode 24a is electrically connected to the electrode 22a, and the extraction electrode 24b is electrically connected to the electrode 22b.

Such IDTs 22 (electrodes 22a and 22b), reflectors 23a and 23b, and extraction electrodes 24a and 24b can be formed of a metal material having excellent conductivity such as aluminum and aluminum alloy, respectively.
By providing such a surface acoustic wave element 2, the piezoelectric device 1 can constitute a SAW device such as a SAW oscillator. The piezoelectric element 2 may be a vibration element other than a surface acoustic wave element such as a thickness-shear vibration piece or a tuning fork type vibration piece.

  Next, the package 3 that houses and fixes the surface acoustic wave element 2 will be described. The package 3 has a substantially rectangular shape in plan view. As shown in FIG. 1, such a package 3 includes a plate-like base substrate 31, a frame-like frame member 32, and a plate-like lid member 33. The base substrate 31, the frame member 32, and the lid member 33 are laminated in this order from the mounting substrate 4 side. The base substrate 31, the frame member 32, and the frame member 32 and the lid member 33 are adhesives, respectively. Or it is joined by brazing material or the like. The package 3 accommodates the surface acoustic wave element 2 in the internal space S defined by the base substrate 31, the frame member 32 and the lid member 33.

As a constituent material of such a base substrate 31, those having insulating properties (non-conductive) are preferable. For example, various ceramics such as various glasses, oxide ceramics, nitride ceramics, carbide ceramics, polyimide Various resin materials such as can be used.
Moreover, as a constituent material of the frame member 32 and the lid member 33, the same constituent material as the base substrate 31, various metal materials such as Al and Cu, various glass materials, and the like can be used, for example.

  As shown in FIGS. 1 and 2, a pair of internal terminals 34 a and 34 b are formed on the upper surface of the base substrate 31 so as to be exposed to the internal space S. On the internal terminals 34a and 34b, epoxy-based and polyimide-based conductive adhesives 39a and 39b are respectively applied (stacked), and further on the conductive adhesives 39a and 39b. The surface acoustic wave element 2 described above is placed with the surface on which the IDT 22a and the like are formed facing upward (the lid member 33 side). Then, the surface acoustic wave element 2 is fixed to the internal terminals 34a and 34b (base substrate 31) by curing the conductive adhesives 39a and 39b.

  In this fixing, the conductive adhesive 39a contacts the extraction electrode 24a (the region of the extraction electrode 24a located on the lower surface of the piezoelectric substrate 21), and the conductive adhesive 39b is connected to the extraction electrode 24b (the extraction electrode 24b). The end of the surface acoustic wave element 2 on which the extraction electrodes 24a and 24b are formed is placed on the conductive adhesives 39a and 39b so as to be in contact with the region located on the lower surface of the piezoelectric substrate 21). Do. As a result, the surface acoustic wave element 2 is fixed to the base substrate 31 via the conductive adhesives 39a and 39b, and the extraction electrode 24a and the internal terminal 34a are electrically connected to the extraction electrode 24b and the internal terminal 34b, respectively. can do.

As shown in FIGS. 1 and 2, four external terminals 35a, 35b, 35c, and 35d are provided on the lower surface of the base substrate 31 so as to be positioned at the four corners. Further, the terminals 35a to 35d are positioned so as to face four connection terminals 41a to 41d, which will be described later, provided on the mounting substrate 4, respectively.
Out of these four external terminals 35a to 35d, the external terminals 35a and 35b are hot terminals electrically connected to the internal terminals 34a and 34b through via holes formed in the base substrate 31, respectively. The other two external terminals 35c and 35d are dummy terminals for increasing the bonding strength (the bonding strength between the spacers 53 and 54 and the package 3) when the package 3 is mounted on the mounting substrate 4, respectively.
Such internal terminals 34a and 34b and external terminals 35a to 35d can be formed, for example, by applying gold plating to an underlying layer of tungsten and nickel plating.

Next, the mounting substrate 4 on which the above package 3 is mounted (fixed) will be described. As shown in FIG. 3, the mounting substrate 4 has a substantially rectangular shape in plan view, and is slightly larger than the base substrate 31 of the package 3 described above.
Such a mounting substrate 4 may be a rigid substrate, a flexible substrate, or a rigid flexible substrate. In addition, the constituent material of the mounting substrate 4 is preferably an insulating (non-conductive) material, for example, various ceramics such as various glasses, oxide ceramics, nitride ceramics, carbide ceramics, polyimide, etc. Various resin materials can be used.

  2 and 3, four connection terminals 41a, 41b, 41c, and 41d and a wiring pattern 42 are formed on the upper surface (the surface on the package 3 side) of the mounting substrate 4. The four connection terminals 41a to 41d are formed near the corners of the mounting substrate 4 so as to face the external terminals 35a to 35d of the package 3, respectively. Of these connection terminals 41a to 41d, connection terminals 41a and 41b corresponding to external terminals (hot terminals) 35a and 35b are electrically connected to the wiring pattern 42, respectively.

On the other hand, as shown in FIG. 1, on the lower surface of the mounting substrate 4, for example, a plurality of mounting terminals 43 that are electrically and mechanically connected to a circuit board (not shown) on which the piezoelectric device 1 is mounted are formed. . Each mounting terminal 43 is electrically connected to the wiring pattern 42 through a via hole formed in the mounting substrate 4.
Note that, on the lower surface of the mounting substrate 4, a writing terminal for rewriting (adjusting) a characteristic inspection of the IC 6 described later and various information inside the IC (for example, temperature compensation information of the piezoelectric device) as necessary. May be formed.

  An electronic component 6 is mounted on the central portion of the upper surface of the mounting substrate 4. The electronic component 6 is, for example, an integrated circuit element (hereinafter also simply referred to as “IC”) as a circuit element for driving the surface acoustic wave element 2. As shown in FIG. 1, such an IC 6 is mounted on the mounting substrate 4 by an insulating (non-conductive) adhesive or an adhesive member 44 such as an adhesive sheet, and further, wire bonding (metal wire 45). ) To be electrically connected to the wiring pattern 42. Thereby, each terminal (connection terminal 41a, 41b and mounting terminal 43) and IC6 are electrically connected via the wiring pattern 42. FIG.

  Such a mounting substrate 4 has the package 3 fixed on its upper surface side via column members (spacers) 51 to 54. The column members 51 to 54 have a function of forming a gap for mounting the IC 6 or the like between the mounting substrate 4 and the package 3. Thereby, since the package 3 and the IC 6 can be stacked (stacked) in the height direction of the piezoelectric device 1, the size of the piezoelectric device 1 can be reduced.

  The column member 51 is provided between the connection terminal 41 a of the mounting substrate 4 and the external terminal 35 a of the package 3. Similarly, the column member 52 is between the connection terminal 41b and the external terminal 35b, the column member 53 is between the connection terminal 41c and the external terminal 35c, and the column member 54 is between the connection terminal 41d and the external terminal 35d. Are provided respectively. Each of the column members 51 to 54 is joined to the connection terminals 41a to 41d and the external terminals 35a to 35d by solder (brazing material).

Hereinafter, although the concrete structure of these column members 51-54 is demonstrated, since these column members 51-54 are the mutually same structures, it demonstrates about the column member 51 as a representative, About the column members 52-54 The description is omitted.
As shown in FIG. 4, the column member 51 is a right-angle column as a whole. Moreover, the cross-sectional shape of the column member 51 is a substantially square shape.

  On such an upper surface (upper end surface) 511 of the column member 51, a recess (recess) 512 that opens to the upper surface 511 is formed. The recess 512 is open at one end to the side surface 513 and at the other end to the side surface 514 facing the side surface 513. Such a concave 512 functions as a solder reservoir for collecting solder for joining the column member 51 and the package 3 (external terminal 35a).

  The recess 512 has a pair of side surfaces 512 a and 512 b that are inclined approximately 90 degrees with respect to the upper surface 511 and parallel to each other, and a bottom surface 512 c that is parallel to the upper surface 511. In other words, the cross-sectional shape of the internal space of the recess 512 has a substantially square shape or a substantially rectangular shape. Although it does not specifically limit as such width W (distance of the side surfaces 512a and 512b) of the groove 512, It is preferable that it is about 0.01 mm-0.1 mm.

Here, the joining of the column member 51 and the package 3 is performed by applying a solder paste (a paste-like brazing material) to the upper surface 511 of the column member so as to cover the opening of the recess 512, as will be described later. However, by setting the width W within the above range, the solder paste applied to the upper surface 511 can be kept so as to cover the opening of the recess 512 without dripping into the recess 512 due to its viscosity. . As a result, as will be described later, when the package 3 and the column member 51 are joined, a solder fillet is formed in the recess 512, and the joining strength thereof can be further increased.
Further, the depth T of the recess 512 is not particularly limited, but is preferably about 0.01 mm to 0.1 mm. The side surfaces 513 and 514 of the recess 512 can have a sufficient area (particularly the length in the height direction of the column member 51) to form the above-described solder fillet, whereby the package 3 and the column member can be formed. The bonding strength of 51 can be further increased.

  Such a column member 51 preferably has conductivity. Thereby, the connection terminal 41a formed on the mounting substrate 4 and the external terminal 35a formed on the package 3 can be electrically connected via the pillar member 51 (that is, via the pillar member 51, IC6 and surface acoustic wave element 2 can be electrically connected). Thereby, the number of parts of the piezoelectric device 1 can be reduced (for example, it is not necessary to provide a metal wire or the like for electrically connecting the connection terminal 41a and the external terminal 35a), and simplification of manufacturing. Cost reduction and size reduction can be achieved.

  The configuration of the column member 51 is not particularly limited as long as the connection terminal 41 a and the external terminal 35 a can be electrically connected via the column member 51. For example, the column member 51 may be composed of various conductive metal materials such as Au, Ag, Cu, and Al as a main material, or a non-conductive substrate composed of various resin materials and ceramics. You may comprise by forming electroconductive films, such as plating, on the surface of this.

Next, a method of joining the column member 51 having such a configuration to the mounting substrate 4 and the package 3 will be described with reference to FIGS. 5 and 6, only the periphery of the column member 51 is illustrated, and the other portions are not illustrated.
First, the column member 51 is bonded to the mounting substrate 4. As shown in FIG. 5, the column member 51 is joined to the mounting substrate 4 by [1] mounting the column member 51 so that the end surface on the side where the recess 512 is not formed faces the mounting substrate 4 side. The step of placing on the connection terminal 41a formed on the upper surface of [2], and [2] by soldering a part or the entire area (entire circumference) of the boundary portion B1 between the column member 51 and the connection terminal 41a. And a bonding terminal 41a (package 3). When soldering the boundary portion B1, the melted solder spreads on the connection terminal 41a, and the fillet 71 is formed so as to cover the boundary portion B1. Thereby, the joining strength of the column member 51 and the joining terminal 41a increases. Moreover, since the fillet 71 can be visually recognized from the outside, the joining state of the column member 51 and the joining terminal 41a can be confirmed easily.

  Next, the package 3 is joined to the upper end surface 511 of the column member 51. As shown in FIG. 6, the bonding of the package 3 to the column member 51 includes [1] a step of applying a solder paste 72 to the upper surface 511 of the column member 51 so as to cover the opening of the recess 512, and [2]. The package 3 is placed on the upper surface 511 of the pillar member 51, and the solder paste 72 is melted and solidified to join the external terminals 35a and the pillar member 51.

Here, when the package 3 is placed on the upper surface 511 of the column member 51 and the solder paste 72 is melted, the solder paste 72 faces the side surfaces 512a and 512b of the recess 512 and the external terminals 35a (the inner space of the recess 512). By spreading out and solidifying in the region, a fillet 73 is formed in the recess 512 so as to cover the boundary B2 between the recess 512 and the external terminal 35a (see FIG. 6C). Thereby, the joint strength between the column member 51 and the external terminal 35a can be increased.
In particular, in this embodiment, the fillet 73 is formed in an arch shape so as to bridge (connect) the side surfaces 512a and 512b of the recess 512 via the external terminal 35a. The bonding strength with the terminal 35a can be further increased.

Further, since the solder paste 72 wets and spreads in the region facing the internal space of the recess 512 of the external terminal 35a and hardly wets and spreads in other regions, the shape (planar shape) of the external terminal 35a can be freely designed. be able to. Thereby, the freedom degree of the design of the piezoelectric device 1 increases.
Further, by using such a column member 51, no fillet is formed on the outside of the column member 51. Therefore, it is not necessary to secure a space for forming a fillet around the upper end surface 511 of the column member 51 in advance. Thus, the piezoelectric device 1 can be reduced in size.
Further, as described above, in the present embodiment, since both ends of the recess 512 are open to the side surfaces 513 and 514 of the column member 51, the fillet 73 formed in the recess 512 is disposed outside the column member 51. Can be visually recognized. Thereby, the joining state of the column member 51 and the external terminal 35a (package 3) can be confirmed easily.

As described above, the piezoelectric device 1 of the present embodiment has been described. As shown in FIG. 7, the molding material 8 made of a fluid resin is poured into the piezoelectric device 1, and the lid member 33 of the package 3 is poured. The entire piezoelectric device 1 may be covered with the molding material 8 so that the upper surface and the lower surface of the mounting substrate 4 are exposed to the outside.
Moreover, in this embodiment, as shown in FIG. 3, although the groove formed in each column member 51-54 is extended in the mutually same direction (vertical direction in FIG. 3), extension of a groove The direction is not particularly limited, and for example, each concave line may extend in the horizontal direction in FIG. 3, or may be mixed with concave lines extending in different directions.

  Moreover, in this embodiment, although it is set as the structure using the four pillar members 51-54 as a spacer, if the function as mentioned above can be exhibited as a spacer, it will not specifically limit about the shape and number. . For example, as the spacer, a frame-like member provided around the entire edge of the mounting substrate 4 may be used, or one to three or five or more column members may be used.

  Moreover, in this embodiment, although the shape of each column member 51-54 was the structure made into the right-angled column whose cross-sectional shape makes a substantially square shape, it does not specifically limit as a shape of each column member 51-54. For example, each of the column members 51 to 54 may have a cross-sectional shape that is circular, elliptical, triangular, pentagonal, or the like. In addition, each of the column members 51 to 54 may have a parallel cross-sectional shape, a trapezoidal shape, or the like.

<Second Embodiment>
Next, a second embodiment of the piezoelectric device of the present invention will be described.
FIG. 8 is a perspective view showing a column member included in the piezoelectric device according to the second embodiment of the present invention. In FIG. 8, the upper side is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.
Hereinafter, the piezoelectric device according to the second embodiment will be described focusing on the differences from the above-described embodiment, and description of similar matters will be omitted.

The piezoelectric device according to the second embodiment of the present invention is the same as that of the first embodiment described above except that the shape of the column member is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
Hereinafter, the four column members 55 will be described. Since these are the same configuration as each other, only one column member 55 will be described as a representative, and description of the other column members 55 will be omitted.

  As shown in FIG. 8, the upper surface 551 of the column member 55 is formed with a recess 552 composed of two recesses 552 a and 552 b that open to the upper surface 551. These two concave strips 552a and 552b are formed so as to be orthogonal to each other. Further, one end of the groove 552a is open to the side surface 554 and the other end is open to the side surface 555 opposite to the side surface 554. The groove 552b has one end facing the side surface 556 and the other end facing the side surface 556. Each side surface 557 is open.

By setting the recess 552 to have such a configuration, for example, a larger area where a fillet can be formed can be ensured than the column member of the first embodiment. Thereby, the joint strength between the column member 51 and the external terminal 35a can be further increased, and the strength of the piezoelectric device is further improved.
In the present embodiment, the two concave strips 552a and 552b are described as being orthogonal to each other. However, the number of such concave strips and the intersecting angle are not particularly limited. Further, the plurality of concave stripes may not intersect each other (that is, may be parallel).

<Third Embodiment>
Next, a second embodiment of the piezoelectric device of the present invention will be described.
FIG. 9 is a plan view and a cross-sectional view showing a pillar member included in a piezoelectric device according to a third embodiment of the present invention, and FIG. 10 is a view showing a joined state between the pillar member and the package shown in FIG. 10 corresponds to a cross section taken along line AA in FIG. Further, the upper side of FIGS. 9 and 10 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.

Hereinafter, the piezoelectric device according to the third embodiment will be described with a focus on differences from the above-described embodiments, and description of similar matters will be omitted.
The piezoelectric device according to the third embodiment of the present invention is the same as that of the first embodiment described above except that the shape of the column member is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
Hereinafter, the four column members 56 will be described. Since these are the same configuration as each other, only one column member 56 will be described as a representative, and description of the other column members 56 will be omitted.

  As shown in FIG. 9, the pillar member 56 has a circular shape in plan view. Further, the upper surface 561 of the column member 56 is configured by a curved convex surface. Further, the upper surface 561 is formed with a concave portion 562 composed of two concave strips 562a and 562b that open to the upper surface 561. The two recesses 562a and 562b are formed so as to be orthogonal to each other. In addition, the curvature of the curved convex surface of the upper surface 561 is not specifically limited, For example, it can be set to 1 / T which is the curvature of the circle | round | yen which makes the depth T of the recessed stripes 562a and 562b a radius.

  When the column member 56 having such a configuration and the external terminal 35a of the package 3 are joined by the same process as in the first embodiment, a fillet 73 is formed in the recess 562 as shown in FIG. A fillet 74 is also formed between 561 and the external terminal 35a. Thereby, the joint strength between the column member 56 and the external terminal 35a can be further increased. In addition, since the fillet 74 does not protrude from the column member 56 in the lateral direction in FIG. 10, the fillet 74 can be prevented from hindering the miniaturization of the piezoelectric device.

In the present embodiment, the configuration of the recess 562 described in which the recess 562 is configured by two recesses 562a and 562b orthogonal to each other is not limited thereto. For example, the angle at which two concave stripes intersect is not limited (does not have to intersect). Also, the number of concave stripes may be one or three or more, for example.
Further, the upper surface 561 of the column member 56 may not be configured by a curved convex surface, and may be configured by, for example, an inclined surface inclined from the center portion of the upper surface 561 toward the edge.

<Fourth embodiment>
Next, a fourth embodiment of the piezoelectric device of the present invention will be described.
FIG. 11 is a perspective view showing a pillar member included in a piezoelectric device according to a fourth embodiment of the present invention, and FIG. 12 is a view showing a joined state between the pillar member and the package shown in FIG. 11 and 12, the upper side is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.

Hereinafter, the piezoelectric device according to the fourth embodiment will be described focusing on the differences from the above-described embodiment, and description of similar matters will be omitted.
The piezoelectric device according to the fourth embodiment of the present invention is the same as that of the first embodiment described above except that the shape of the column member is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
Hereinafter, the four column members 57 will be described. Since these are the same configuration as each other, only one column member 57 will be described as a representative, and description of the other column members 57 will be omitted.

As shown in FIG. 11, the upper surface 571 of the column member 57 is composed of a pair of inclined surfaces 571a and 571b inclined downward from the opposite sides 572a and 572b toward the center. Further, the upper surface 571 is formed with a recess 573 that opens to the upper surface 571. The concave line 573 extends in a direction parallel to the sides 572a and 572b, and has one end opened to the side surface 574 and the other end opened to the side surface 575 facing the side surface 574.
When the column member 57 having such a configuration and the external terminal 35a of the package 3 are joined by the same process as in the first embodiment, as shown in FIG. 12, not only in the recess 573 but also the upper surface 571 (inclined surface). 571a, 571b) and the external terminal 35a are also formed with fillets 74. Thereby, the joint strength between the column member 57 and the external terminal 35a can be further increased.

The piezoelectric device of the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and the configuration of each part is replaced with an arbitrary configuration having the same function. be able to. Moreover, other arbitrary structures and processes may be added. Moreover, the piezoelectric device of the present invention may be a combination of any two or more configurations (features) of the above-described embodiments.
In the above-described embodiment, the configuration using the surface acoustic wave element as the piezoelectric element has been described. However, the piezoelectric element is not limited to this, and may be, for example, a gyro sensor using a piezoelectric body such as crystal. There may be.

  DESCRIPTION OF SYMBOLS 1 ... Piezoelectric device 2 ... Piezoelectric element (surface acoustic wave element) 21 ... Piezoelectric substrate 22a, 22b ... IDT 23a, 23b ... Reflector 24a, 24b ... Extraction electrode 3 ... Package 31 ... Base Substrate 32 ... Frame member 33 ... Lid member 34a, 34b ... Internal terminal 35a to 35d ... External terminal 39a, 39b ... Conductive adhesive 4 ... Mounting substrate 41a to 41d ... Connection terminal 42 ... Wiring Pattern 43 ... Mounting terminal 44 ... Adhesive member 45 ... Metal wire 51 to 54 ... Column member (spacer) 511 ... Upper surface 512 ... Recess (recess) 512a, 512b ... Side surface 512c ... Bottom surface 513, 514 …… Side surface 55 …… Column member 551 …… Top surface 552 …… Recess 552a, 552b …… Recess 554-557 …… Side 56 …… Member 561 …… Top surface 562 …… Concavity 562a, 562b …… Concave strip 57 …… Column member 571 …… Top surface 571a, 571b …… Inclined surface 572a, 572b …… Side 573 …… Concave strip 574, 575 …… Side 6 …… Electronic components (IC) 71, 73, 74 …… Fillet 72 …… Solder paste 8 …… Mold material

Claims (7)

A package containing a piezoelectric element;
A mounting substrate that supports the package;
A spacer provided between the package and the mounting substrate, and forming a gap between the package and the mounting substrate;
An electronic component disposed in the gap and for driving the piezoelectric element;
The spacer has a recess that opens to the end surface on the package side,
The said spacer and the said package are joined by the brazing | wax material stored in the said recessed part, The piezoelectric device characterized by the above-mentioned.   The piezoelectric device according to claim 1, wherein a fillet is formed inside the recess.   The piezoelectric device according to claim 2, wherein the fillet is formed in an arch shape that connects a pair of opposing side surfaces of the recess. The spacer has a columnar shape,
The piezoelectric device according to any one of claims 1 to 3, wherein the concave portion has a concave line whose both ends are open to a side surface of the spacer.   The piezoelectric device according to claim 4, wherein the recess has a plurality of the recesses, and at least two of the recesses intersect each other. The electronic component is mounted on the mounting board,
The piezoelectric device according to any one of claims 1 to 5, wherein the spacer has conductivity and electrically connects the piezoelectric element and the electronic component.   The piezoelectric device according to claim 1, wherein an end surface of the spacer on the package side is configured by a curved convex surface.

Images