JP5369889B2 - Vibration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration device for avoiding the damage of a vibrating-reed, etc., caused by static electricity. <P>SOLUTION: The vibration device includes: a package base 20; a lid 30 to be joined with the package base 20; and a crystal vibrating-reed 10 to be stored in an internal space surrounded by the package base 20 and the lid 30. The package base 20, where a through-hole 26 for communication from the internal space to an external part is formed, includes on an outer bottom surface 23: a first terminal 27 and a second terminal 28 which are arranged at one end and the other end, respectively, in a first axial direction B in parallel with a pair of opposing sides 23a, 23b of the outer bottom surface 23; and a third terminal 29 arranged between the first and second terminals 27, 28. The first terminal 27 and the second terminal 28 are electrically connected to the crystal vibrating-reed 10. The third terminal 29 is electrically connected to the lid 30. The third terminal 29 and the through-hole 26 are mutually arranged by separation each other in plan view of the outer bottom surface 23. The through-hole 26 is sealed with a sealing material 70. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vibration device represented by a piezoelectric vibrator and the like.

  Conventionally, a piezoelectric vibrating piece is accommodated as a vibrating piece in an internal space of a package, an opening portion of the package is covered with a lid, the piezoelectric vibrating piece is connected to an electrode portion formed on an inner bottom portion of the package, and the electrode portion is connected to the package. There is known a vibrating device having a configuration that is routed to the outside to form a mounting terminal (see, for example, Patent Document 1).

JP 2003-318691 A

In the vibrating device configured as described above, static electricity generated for some reason may be discharged to the mounting terminals formed on the outer bottom surface of the package via the lid.
As a result, in the vibrating device, the static electricity discharged to the mounting terminal reaches the vibrating piece through the electrode portion. Therefore, depending on the magnitude of the electrostatic energy, the vibrating piece may be damaged and the characteristics may deteriorate. There is.
Further, in the vibration device, even if the vibration piece does not have to be damaged, the stray capacitance may fluctuate due to static electricity remaining on the lid, and the vibration characteristics of the vibration piece may be deteriorated.

  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 vibrating device according to this application example includes a package base, a lid joined to the package base, a vibrating piece housed in an internal space surrounded by the package base and the lid, A through hole communicating with the outside from the internal space is formed in the package base, and the package base is provided on the outer bottom surface in one of the first axial directions parallel to a pair of opposite sides of the outer bottom surface. A first terminal provided at an end, a second terminal provided at the other end, and a third terminal provided between the first terminal and the second terminal; The terminal and the second terminal are electrically connected to the vibrating piece, the third terminal is electrically connected to the lid, and the third terminal and the through hole are flat surfaces of the outer bottom surface. The said penetrations are arranged apart from each other in view There, a vibration device, characterized in that is sealed with a plug.

According to this, in the vibration device, the first terminal and the second terminal provided on the outer bottom surface of the package base are electrically connected to the vibration piece, and the third terminal is electrically connected to the lid. Yes.
As a result, the vibration device is, for example, a mounting board of an external device on which the vibration device is mounted via the third terminal electrically connected to the lid when static electricity is discharged to the lid. It is easy to release static electricity.
Therefore, the vibration device can maintain good vibration characteristics because fluctuations in stray capacitance due to discharged static electricity, damage to the vibration piece, and the like are avoided.

In the vibration device, the third terminal and the through hole are arranged apart from each other, and the through hole is sealed with a sealing material.
As a result, when the vibrating device is mounted on an external device, for example, the mounting solder flows out from the third terminal to the through hole as compared with the case where the third terminal and the through hole are close to each other. Can be avoided.
Therefore, since the vibration device can avoid the deterioration of the sealing material due to the solder, the reliability of the sealing of the through hole by the sealing material can be favorably maintained.

  Application Example 2 In the vibration device according to Application Example 1, the package base includes a bottom substrate and a frame substrate that surrounds the vibration piece and is stacked on the bottom substrate. 2. A vibration device comprising: a bottom substrate through hole that is at least a part of a hole, wherein the bottom substrate through hole overlaps with the frame substrate in a plan view.

According to this, the vibration device includes a package base that includes a bottom substrate and a frame substrate that surrounds the resonator element and is stacked on the bottom substrate, and the through hole is formed in the bottom substrate so as to at least partially overlap the frame substrate. Is formed.
As a result, the vibration device can be reduced in size and thickness because the package base can be reduced in size and thickness.

  Application Example 3 In the vibration device according to Application Example 2, in the frame substrate, a frame substrate through hole that is a part of the through hole and penetrates in the thickness direction of the frame substrate is formed in the frame substrate. A vibration device, wherein a hole is formed in a region of the bottom substrate through hole of the bottom substrate in a plan view.

According to this, the vibration device includes the frame substrate through-hole through which the frame substrate penetrates in the thickness direction of the frame substrate, and the frame substrate through-hole is formed at a position overlapping the bottom substrate through-hole of the bottom substrate.
As a result, the vibration device can be reduced in size and thickness because the package base can be reduced in size and thickness.

  Application Example 4 In the vibration device according to any one of Application Examples 1 to 3, at least a part of the third terminal is in the second axis direction orthogonal to the first axis of the package base. A vibrating device characterized by being formed over the entire width of one terminal or the second terminal in the second axial direction.

According to this, in the vibration device, at least a part of the third terminal is formed over the entire width of the first terminal or the second terminal in the second axial direction.
As a result, in the vibration device, for example, in the manufacturing process of the package base, the deformation such as the undulation of the package base at the time of pressing the facing surface facing the outer bottom surface is caused by the third terminal and the first terminal or the second terminal. It can suppress suitably compared with the case where the formation range of a biaxial direction differs.

The schematic diagram which shows schematic structure of the crystal oscillator of this embodiment. FIG. 6 is a schematic cross-sectional view showing a schematic configuration of a crystal resonator according to Modification 1. The model back top view which shows schematic structure of the crystal resonator of the modification 2. The model back top view which shows schematic structure of the crystal resonator of the modification 3.

Hereinafter, embodiments of the vibration device will be described with reference to the drawings.
(Embodiment)
Here, as an example of the vibration device, a crystal resonator that is a piezoelectric vibration device will be described as an example.
FIG. 1 is a schematic diagram showing a schematic configuration of a crystal resonator according to the present embodiment. 1A is a front plan view as viewed from the lid side, FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A, and FIG. 1C is as viewed from the package base side. It is a back top view.
In the front plan view, the lid is omitted for easy understanding, and the outer shape of the lid is indicated by a two-dot chain line.

  As shown in FIG. 1, the crystal resonator 1 includes a crystal resonator element 10 as a piezoelectric resonator element, a package base 20 on which the crystal resonator element 10 is mounted, and a lid that covers the crystal oscillator piece 10 and is joined to the package base 20. And a body 30.

The quartz crystal vibrating piece 10 is a tuning fork type quartz crystal vibrating piece including a base portion 11 having a substantially rectangular planar shape and a pair of prismatic vibrating arm portions 12 extending from one end of the base portion 11 substantially in parallel to each other. Note that an excitation electrode (not shown) is formed on the crystal vibrating piece 10.
The package base 20 includes a flat bottom substrate 21 having a substantially rectangular planar shape, and a frame-shaped frame substrate 22 that surrounds the crystal resonator element 10 mounted on the bottom substrate 21 and is stacked on the bottom substrate 21. Yes.
For the bottom substrate 21 and the frame substrate 22, an aluminum oxide sintered body formed by firing a ceramic green sheet is used.

A bottom substrate through-hole 24 is formed in the bottom substrate 21 from an inner bottom surface 21a that is a surface on which the crystal resonator element 10 inside the package base 20 is mounted to reach an outer bottom surface 23 that is a bottom surface outside the package base 20. Yes. Further, the frame substrate 22 includes a frame substrate through hole 25 that penetrates in the thickness direction of the frame substrate 22.
The frame substrate through hole 25 is formed at a position overlapping the bottom substrate through hole 24 in plan view. Further, the planar size of the bottom substrate through hole 24 is formed larger than the planar size of the frame substrate through hole 25.

The planar shape of the bottom substrate through hole 24 and the frame substrate through hole 25 is usually circular, but may be a triangle, a quadrangle, a pentagon or more polygon, an ellipse, or the like.
By the bottom substrate through hole 24 and the frame substrate through hole 25, the package base 20 is formed with a stepped through hole 26 that reaches the outer bottom surface 23 of the bottom substrate 21 from the surface 22 a on the lid body 30 side of the frame substrate 22. .
Hereinafter, when it is not necessary to distinguish the bottom substrate through hole 24 and the frame substrate through hole 25, they are referred to as a through hole 26.

The outer bottom surface 23 of the package base 20 is provided with a first terminal 27 at one end in the first axial direction B parallel to the pair of sides 23a and 23b, and a second terminal 28 at the other end. ing. The first terminal 27 and the second terminal 28 are substantially rectangular and have the same size.
A third terminal 29 is provided between the first terminal 27 and the second terminal 28 on the outer bottom surface 23 of the package base 20.

  Here, as shown in FIG. 1C, a part of the third terminal 29 is part of the entire width of the second terminal 28 in the second axial direction C in the second axial direction C perpendicular to the longitudinal direction of the package base 20. L is formed over L. The formation range of the third terminal 29 in the second axial direction C may extend over the entire width of the first terminal 27 in the second axial direction C.

Further, the third terminal 29 and the through hole 26 are arranged apart from each other when the outer bottom surface 23 is viewed in plan. More specifically, the metal coating constituting the third terminal 29 is arranged away from the through hole 26 on the outer bottom surface 23 so as not to reach the through hole 26. Here, the third terminal 29 and the through hole 26 indicate that, for example, when the crystal unit 1 is mounted on an external device, solder for mounting that has spread to the third terminal 29 flows out to the through hole 26. Not far away.
Thus, the third terminal 29 has a substantially rectangular shape with a part cut out on the through hole 26 side.
The first terminal 27, the second terminal 28, and the through hole 26 pass through the third terminal 29 and the through hole 26 so that the mounting solder wetted and spread on the first terminal 27 and the second terminal 28 does not flow out to the through hole 26. It is preferable that the gap is formed more than the distance from the hole 26.

  The first terminal 27, the second terminal 28, and the third terminal 29 are made of a metal film obtained by laminating each film such as nickel and gold on a metallized layer such as tungsten by plating.

Internal electrodes 21 b and 21 c are formed on the inner bottom surface 21 a of the package base 20, and the crystal vibrating piece 10 is mounted via a conductive adhesive 40 such as epoxy, silicon, or polyimide. For mounting the crystal vibrating piece 10, a bonding material such as solder or bump may be used instead of the conductive adhesive 40.
The quartz crystal resonator element 10 has a mount electrode electrically connected to the excitation electrode formed on the base 11 and is mounted so that the mount electrode overlaps the internal electrodes 21b and 21c. Thereby, in the crystal resonator 1, the excitation electrode of the crystal resonator element 10 and the internal electrodes 21b and 21c are electrically connected.

The internal electrodes 21b and 21c are electrically connected to the first terminal 27 and the second terminal 28, respectively, through internal wiring (not shown). For example, the internal electrode 21 b is connected to the first terminal 27, and the internal electrode 21 c is connected to the second terminal 28.
Accordingly, the first terminal 27 and the second terminal 28 are electrically connected to the crystal vibrating piece 10.
The internal electrodes 21b and 21c are made of a metal film obtained by laminating a film of nickel, gold or the like on a metallized layer of tungsten or the like by plating or the like, similar to the above terminals.

A metallized layer such as tungsten (not shown) is formed on the surface 22a of the frame substrate 22 of the package base 20 on the lid 30 side, and a plane made of a metal such as kovar via a joining member 50 such as a seam ring or a brazing material. The flat lid body 30 having a substantially rectangular shape is joined.
Here, as shown in FIG. 1B, the third terminal 29 is electrically connected to the lid 30 via an internal wiring using a via 29 a penetrating the bottom substrate 21 and the frame substrate 22, and the joining member 50. Connected.
Here, a housing portion that houses the crystal vibrating piece 10 including the package base 20, the lid body 30, and the bonding member 50 is referred to as a package 60. A space surrounded by the package 60 and accommodating the crystal vibrating piece 10 is referred to as an internal space.

In the crystal unit 1, the through hole 26 is made of a metal such as a gold / germanium alloy, a gold / tin alloy, or a silver braze in a state where the internal space of the package 60 is evacuated using a vacuum chamber or the like. It is sealed with a material 70.
The sealing material 70 is formed in a substantially spherical shape and is heated and melted by irradiation with a laser beam or an electron beam or using a heater or the like while being placed in the bottom substrate through hole 24 of the inverted package 60. Thus, the through hole 26 is filled. If the bottom substrate through hole 24 is securely sealed, the frame substrate through hole 25 is not necessarily filled with the sealing material 70.

  In the crystal unit 1, the internal space of the package 60 is maintained in a vacuum state by sealing the through hole 26 that communicates the internal space of the package 60 and the outside of the crystal unit 1 with a sealing material 70. The crystal vibrating piece 10 is excited by a drive signal applied via the first terminal 27 and the second terminal 28 and resonates at a predetermined frequency.

As described above, in the crystal resonator 1, the first terminal 27 and the second terminal 28 provided on the outer bottom surface 23 of the package base 20 are electrically connected to the crystal vibrating piece 10, and the third terminal 29 is The lid 30 is electrically connected.
As a result, for example, when the static electricity is discharged to the lid body 30, the crystal vibrator 1 is mounted via the third terminal 29 electrically connected to the lid body 30. Static electricity is easily released to the mounting board of external equipment.
Therefore, in the crystal resonator 1, the static electricity stays in the lid body 30 and the floating capacitance fluctuates, or the static electricity reaches the crystal vibrating piece 10 through the first terminal 27 and the second terminal 28, and the crystal vibrating piece 10 is damaged. Therefore, good vibration characteristics can be maintained.

Further, in the crystal resonator 1, the third terminal 29 and the through hole 26 are disposed apart from each other when the outer bottom surface 23 is viewed in plan, and the through hole 26 is sealed with a sealing material 70.
As a result, when the crystal unit 1 is mounted on an external device, for example, the solder that spreads wet to the third terminal 29 compared to the case where the third terminal 29 and the through hole 26 are close to each other. However, it is possible to avoid outflow into the through hole 26.
Therefore, the crystal unit 1 is deteriorated in the sealing material 70 due to contact with the solder (a phenomenon in which the sealing material 70 is eroded by the solder, specifically, the gold component contained in the sealing material 70 by the solder). Therefore, the reliability of sealing of the through hole 26 by the sealing material 70 can be maintained well.

In addition, the crystal unit 1 is provided on the outer bottom surface 23 of the package base 20 with a first terminal 27 provided at one end portion in the first axial direction B of the package base 20 and a second terminal provided at the other end portion. It has a terminal 28 and a third terminal 29 provided between the first terminal 27 and the second terminal 28.
As a result, the crystal resonator 1 has a shorter distance between the terminals than when the third terminal 29 is not provided.

  As a result, the crystal unit 1 is used for the purpose of correcting warpage of the sheet-like bottom substrate 21 in which the plurality of bottom substrates 21 are connected in the process of manufacturing the bottom substrate 21 of the package base 20, for example. When the inner bottom surface 21a is pressed (during pressing), deformation such as undulation of the bottom substrate 21 due to a step between the outer bottom surface 23 of the bottom substrate 21 and the mounting surface of each terminal is compared with the case where there is no third terminal 29. Can be suppressed.

In addition, in the crystal unit 1, a part of the third terminal 29 is formed over the entire width L of the second terminal 28 in the second axial direction C orthogonal to the longitudinal direction of the package base 20.
As a result, the crystal resonator 1 is deformed such as the undulation of the bottom substrate 21 when the formation range of the third terminal 29 in the second axial direction C is narrower than the entire width L of the second terminal 28 in the same direction. In comparison, it can be further suppressed.

Further, the crystal resonator 1 includes a package base 20 that includes a bottom substrate 21 and a frame substrate 22 that surrounds the crystal resonator element 10 mounted on the bottom substrate 21 and is stacked on the bottom substrate 21. The frame substrate through hole 25 is provided, and the entire frame substrate through hole 25 is formed in a region overlapping the bottom substrate through hole 24 of the bottom substrate 21 in plan view.
As a result, the crystal resonator 1 can be reduced in size and thickness because the package base 20 can be reduced in size and thickness as compared with, for example, a configuration in which the bottom substrate 21 has two layers. Can do.
In the present embodiment, the entire frame substrate through hole 25 has been described as an example of a configuration in which the entire frame substrate through hole 25 overlaps the bottom substrate through hole 24 in plan view. The package base 20 can be reduced in size and thickness as long as the package base 20 is disposed in a region overlapping the bottom substrate through hole 24.

Here, the modification of the said embodiment is demonstrated.
(Modification 1)
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the crystal resonator of the first modification. The cross-sectional position is the same position as the cross-sectional view of FIG. Moreover, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 2, in the crystal resonator 101 of the first modification, the frame substrate through hole 25 (see FIG. 1) of the frame substrate 122 of the package base 120 is deleted.
The crystal unit 101 is formed such that a part of the bottom substrate through hole 124 formed in the bottom substrate 121 overlaps the frame substrate 122 in plan view. Specifically, the frame substrate 122 has a hole for accommodating the crystal vibrating piece 10, but has no through-hole for sealing. Then, the frame substrate 122 is arranged on the bottom substrate 121 so that the inner edge on the lower surface side (the surface side in contact with the bottom substrate 121) of the frame substrate 122 is located in the region of the bottom substrate through hole 124 in plan view. ing.

According to this, since the crystal substrate 101 has the frame substrate through hole 25 of the frame substrate 122 removed, the size of the package base 120 in the second axial direction C (see FIG. 1) is the same as that of the above embodiment. In comparison, it can be further reduced.
Therefore, the crystal resonator 101 can be reduced in planar size as compared with the above embodiment.

(Modification 2)
FIG. 3 is a schematic back plan view showing a schematic configuration of the crystal resonator of the second modification. In addition, about a common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 3, the crystal resonator 201 of the second modification has a different shape of the third terminal 229 compared to the above embodiment.
Compared with the above-described embodiment, the crystal resonator 201 is formed such that the entire width L1 of the third terminal 229 in the first axial direction B of the package base 20 is narrow, and thus the third terminal 229, the first terminal 27, and The interval is widened.

  According to this, since the interval between the third terminal 229 and the first terminal 27 is wider as compared with the above-described embodiment, for example, when the crystal resonator 201 is mounted on an external device, It is possible to avoid the possibility that the first terminal 27 and the second terminal 28 are short-circuited via the third terminal 229 due to the outflow of the solder wetted and spread on the third terminal 229.

(Modification 3)
FIG. 4 is a schematic back plan view showing a schematic configuration of the crystal resonator of the third modification. In addition, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 4, the crystal resonator 301 of the third modification is different in the shape of the third terminal 329 compared to the above embodiment.
In the crystal resonator 301, the total width L 2 of the third terminal 329 in the second axial direction C perpendicular to the first axial direction B of the package base 20 is narrower than the total width L of the second terminal 28 compared to the above embodiment. By being formed, the distance between the third terminal 329 and the through hole 26 is widened.

  According to this, since the interval between the third terminal 329 and the through hole 26 is larger than that in the above embodiment, the crystal resonator 301 is, for example, when mounted on an external device. It is possible to more reliably avoid the solder that has spread to the three terminals 329 from flowing into the through hole 26.

Further, since the crystal resonator 301 has a configuration in which the distance between the third terminal 329 and the through hole 26 is widened, the degree of freedom of arrangement of the through hole 26 is increased, and thus the through hole 26 is biased to any of the terminals. Can be placed in no position.
According to this, for example, when the crystal unit 301 is mounted on an external device, it is possible to substantially uniformly prevent the solder that has spread from the terminals from flowing into the through holes 26.
Note that the configurations of Modifications 2 and 3 can also be applied to Modification 1.

In the above-described embodiment and each modification, the tuning fork type crystal vibrating piece has been described as an example of the quartz crystal vibrating piece 10, but the present invention is not limited to this, and the AT vibrating crystal piece is not limited to this. Alternatively, a surface acoustic wave crystal vibrating piece may be used.
Further, as a material of the piezoelectric vibrating piece, lithium tantalate, lithium niobate, or the like may be used in addition to quartz.
Furthermore, it is possible to use various vibrating pieces other than the piezoelectric vibrating piece instead of the quartz vibrating piece 10. For example, a MEMS (Micro Electro Mechanical Systems) vibrating piece formed by processing a silicon substrate may be used. Good.

  In the above embodiment and each modified example, the description has been given taking the crystal resonator as an example of the vibration device. However, the present invention is not limited to this, and is applicable to an oscillator such as a crystal oscillator in which an oscillation circuit is incorporated in the crystal resonator. it can.

  DESCRIPTION OF SYMBOLS 1 ... Quartz crystal resonator, 10 ... Crystal vibrating piece, 11 ... Base part, 12 ... Vibrating arm part, 20, 120 ... Package base, 21, 121 ... Bottom substrate, 21a ... Inner bottom surface, 21b, 21c ... Internal electrode, 22, 122: Frame substrate, 22a: Surface on the lid side of the frame substrate, 23: Outer bottom surface, 24 ... Bottom substrate through hole, 25 ... Frame substrate through hole, 26 ... Through hole, 27 ... First terminal, 28 ... Second terminal , 29 ... third terminal, 30 ... lid, 40 ... conductive adhesive, 50 ... bonding member, 60 ... package, 70 ... sealing material.

Claims (4)

A vibrating piece,
The first surface and a second surface that is behind the first surface and has a substantially rectangular shape in plan view, and is disposed on the second surface along the first side of the substantially rectangular shape. A first terminal electrically connected to the piece, a second terminal arranged along a second side opposite to the first side and electrically connected to the vibrating piece, and the first A package base having a third terminal disposed between the terminal and the second terminal, and having a through-hole penetrating from the first surface to the second surface;
A lid that seals the resonator element between the first surface and is electrically connected to the third terminal ;
The through hole is sealed with a sealing material, and is in a range of a width in a direction intersecting the first side or the second side of the third terminal in a plan view, and the first An oscillating device characterized by being arranged apart from three terminals . The vibrating device according to claim 1,
The vibration device according to claim 3, wherein the third terminal has a cutout shape in a plan view . The vibrating device according to claim 2,
In a plan view, at least a part of the through hole is arranged within a range of a width in a direction along the first side or the second side of the third terminal. . The vibrating device according to any one of claims 1 to 3,
In a plan view, at least a part of the third terminal extends over the entire width in the direction along the first side or the second side of the first terminal or the second terminal. Vibration device.

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