JP2007208537A - Junction structure for piezoelectric vibration chip, and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a junction structure for a piezoelectric vibration chip whereby a mount area of a piezoelectric device utilizing a downsized piezoelectric vibration chip can be furthermore decreased and to provide the piezoelectric device. <P>SOLUTION: The junction structure of the piezoelectric vibration chip is characterized in that the piezoelectric vibration chip 30 formed with an exciting part 30a by providing exciting electrodes 44, 45 to the front side of a piezoelectric body is joined with a side of a package 20, and side edge parts 32a of the piezoelectric vibration chip 30 other than the exciting part 30a are directly joined with an inner bottom 20a of the package 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrating piece bonding structure bonded to a package side, and a piezoelectric device.

FIG. 8 shows a conventional piezoelectric device 1 widely used in small information devices such as HDDs (hard disk drives), mobile computers, or IC cards, and mobile communication devices such as mobile phones and automobile phones. It is a schematic longitudinal cross-sectional view.
The piezoelectric device 1 in this figure is configured to accommodate a piezoelectric vibrating piece 2 in a rectangular package 3 (see, for example, Patent Document 1).

That is, the package 3 has a rectangular shape as a whole, and has an internal space S inside thereof. The bottom surface 3a exposed to the internal space S is electrically connected to the mounting terminals 4 and 4 (see FIG. Not shown). The electrodes (not shown) and the piezoelectric vibrating piece 2 are connected by conductive adhesives 5 and 5 so that the main surface of the piezoelectric vibrating piece 2 is horizontal.
However, in recent years, electronic devices described above have been remarkably miniaturized, and it is desired to reduce the mounting area of the piezoelectric device 1 used in the electronic device.

  In this regard, as shown in FIG. 9 showing another example of the conventional piezoelectric device, if the main surface of the piezoelectric vibrating piece 7 is set along the height direction, the mounting area of the piezoelectric device 6 seems to be reduced. . That is, the piezoelectric device 6 in FIG. 9 is supported by a plurality of frames 9 electrically connected to the mounting terminals 8 via lead wires so as to sandwich the main surface of the piezoelectric vibrating piece 7. (See, for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2004-343541 Japanese Patent Laid-Open No. 2004-36397

  However, due to recent technological advances, the size of piezoelectric vibrating reeds has been remarkably reduced. At present, for example, a so-called tuning fork-type piezoelectric vibrating reed having two resonating arms extending in parallel with each other from the base portion has a width. It has dimensions of 1.2 mm, length of 2 mm, and thickness of 0.6 mm, and is extremely miniaturized. For this reason, the main surface of the piezoelectric vibrating reed 7 no longer has a space necessary to be supported and fixed by being sandwiched by the frame 9 as shown in FIG. It is difficult to stand the piece 7 vertically.

  An object of the present invention is to provide a piezoelectric vibrating piece joining structure and a piezoelectric device that can further reduce the mounting area of a piezoelectric device using a miniaturized piezoelectric vibrating piece.

  According to the first aspect of the present invention, there is provided a piezoelectric vibrating piece joining structure in which a piezoelectric vibrating piece having an excitation portion having an excitation electrode formed on the surface of a piezoelectric body is joined to a package side. A side edge portion other than the excitation portion of the piezoelectric vibrating piece is achieved by a piezoelectric vibrating piece joining structure that is directly joined to the inner bottom side of the package.

According to the configuration of the first invention, the side edge portion of the piezoelectric vibrating piece is directly joined to the inner bottom side of the package. For this reason, the inner bottom of the package that accommodates the piezoelectric vibrating piece only needs to be formed corresponding to the area of the side edge portion that is significantly smaller than the area of the main surface of the piezoelectric vibrating piece. Even a miniaturized piezoelectric vibrating piece with no margin can be joined to the package side by effectively utilizing its side edge. Further, since the portion of the piezoelectric vibrating piece joined to the package is a side edge portion other than the excitation portion, there is little adverse effect on the vibration characteristics of the piezoelectric vibrating piece.
Therefore, according to the present invention, it is possible to provide a bonded structure of a piezoelectric vibrating piece that can further reduce the mounting area of a piezoelectric device that uses a miniaturized piezoelectric vibrating piece.

  According to a second aspect of the present invention, there is provided a piezoelectric vibrating piece joining structure in which a piezoelectric vibrating piece having an excitation portion having an excitation electrode formed on the surface of a piezoelectric body is joined to a package side. A fixed arm joined to the package is formed so as to extend from a region other than the excitation portion of the piezoelectric vibrating piece, and the fixed arm has a side edge facing the inner bottom of the package. Thus, this is achieved by the bonding structure of the piezoelectric vibrating reed that is directly bonded to the package side.

According to the configuration of the second invention, the fixed arm joined to the package of the piezoelectric vibrating piece is directly joined to the package such that the side edge portion faces the inner bottom of the package. . Accordingly, since the inner bottom of the package that accommodates the piezoelectric vibrating piece only needs to be formed corresponding to the area of the side edge portion of the opposing piezoelectric vibrating piece, the mounting area can be significantly reduced.
Further, by forming a fixed arm for joining to the package, even if the piezoelectric vibrating piece is reduced in size and has no space on the main surface, the package is also applied to portions other than the side edge portion of the piezoelectric vibrating piece. Can be securely bonded to the package.

According to a third invention, in the configuration of the second invention, a lead electrode is provided on the surface of the piezoelectric body so as to pull out the excitation electrode, and the portion of the fixed arm joined to the package Is characterized in that a pair of connection electrodes connected to the package-side electrode are provided so as to extend the extraction electrode.
According to the configuration of the third invention, the portion of the fixed arm joined to the package is provided with a pair of connection electrodes that are connected to the package-side electrode so as to extend the extraction electrode. If the connecting electrode of the fixed arm and the electrode on the package side are joined using a conductive adhesive, electromechanical connection can be achieved.

According to a fourth invention, in the configuration of the third invention, the pair of polarized electrodes of the extraction electrode and the connection electrode have substantially the same area.
According to the configuration of the fourth invention, since the pair of polarized electrodes of the extraction electrode and the connection electrode have substantially the same area, it is possible to supply voltages in a balanced manner with the same electric capacity. .

According to a fifth invention, in the configuration of the third or fourth invention, a groove is formed between a pair of polarized electrodes of the connection electrode.
According to the fifth aspect of the invention, since the groove is formed between the pair of polarized electrodes of the connection electrode, the contact of the conductive adhesive connected to each of the pair of electrodes is prevented. Can prevent short circuit.

According to a sixth invention, in the configuration of the first to fifth inventions, the piezoelectric vibrating piece projects from the region other than the excitation portion toward the opening side of the package when bonded to the package side. It has the protrusion part which has.
According to the configuration of the sixth aspect of the invention, the piezoelectric vibrating reed has the protruding portion that protrudes from the region other than the excitation portion toward the opening of the package when bonded to the package side. For this reason, when the piezoelectric vibrating reed is joined to the package side, if the piezoelectric vibrating reed is mounted by holding the protruding portion with an adsorber or the like, the opening of the package becomes narrow and the adsorber or the like Even when it cannot be inserted into the package, the piezoelectric vibrating piece can be accurately bonded to the package.

  According to a seventh aspect of the present invention, there is provided a piezoelectric vibrating piece in which an excitation part having an excitation electrode is formed on the surface of a piezoelectric body, and a package that accommodates the piezoelectric vibrating piece. This is achieved by a piezoelectric device in which the side edge portion other than the excitation portion of the piezoelectric vibrating piece is directly joined to the inner bottom side of the package.

According to the configuration of the seventh invention, since the side edge portion of the piezoelectric vibrating piece is directly joined to the inner bottom side of the package, the inner bottom of the package is piezoelectric as in the first invention. It is only necessary to provide an area corresponding to the area of the side edge of the resonator element, and even a piezoelectric resonator element that is downsized and has no space on the main surface can be joined to the package side. Further, since the portion of the piezoelectric vibrating piece joined to the package is a side edge portion other than the excitation portion, there is little adverse effect on the vibration characteristics of the piezoelectric vibrating piece.
Therefore, according to the present invention, it is possible to provide a piezoelectric device that can further reduce the mounting area of the piezoelectric device that uses the miniaturized piezoelectric vibrating piece.

  According to an eighth aspect of the present invention, there is provided a piezoelectric vibrating piece in which an excitation electrode is provided on the surface of a piezoelectric body to form an exciting portion, and a package that accommodates the piezoelectric vibrating piece. A fixed arm joined to the package so as to extend from a region other than the excitation portion of the piezoelectric vibrating piece, and the fixed arm has a side edge portion thereof. Is achieved by a piezoelectric device which is directly bonded to the package side so as to face the inner bottom of the package.

  According to the configuration of the eighth invention, the fixed arm of the piezoelectric vibrating piece to be bonded to the package is directly bonded to the package such that the side edge portion faces the inner bottom of the package. . For this reason, as in the second invention, the inner bottom of the package that accommodates the piezoelectric vibrating piece only needs to be formed corresponding to the area of the side edge that is significantly smaller than the area of the main surface of the piezoelectric vibrating piece. Further, even a miniaturized piezoelectric vibrating piece having no space on the main surface can be joined to the package side.

1 to 3 show a piezoelectric device 10 according to a first embodiment of the present invention. FIG. 1 is a schematic plan view of the piezoelectric device 10 (that is, when the piezoelectric device 10 is connected to a mounting substrate, FIG. 2 is a schematic sectional view taken along line AA in FIG. 1, and FIG. 3 is an end view taken along line BB in FIG.
The term “piezoelectric device” refers to all products in which a piezoelectric vibrating piece is accommodated in a package, regardless of the name of a piezoelectric vibrator, a piezoelectric oscillator, a piezoelectric gyro sensor, or the like.
Further, for the convenience of understanding, the portion indicated by the parallel oblique lines in FIG. 2 indicates the electrode portion of the piezoelectric vibrating piece, and does not indicate a cross section or the like.

The piezoelectric device 10 in these drawings shows an example in which a surface-mount type piezoelectric vibrator is configured. The piezoelectric device 10 houses a piezoelectric vibrating piece 30 in a package 20.
The package 20 has an inner bottom 20 a that is surrounded by an inner wall and to which the piezoelectric vibrating piece 30 is bonded.

Specifically, the package 20 is formed by, for example, laminating a first substrate 21 and a second substrate 22 formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering. Has been.
The first substrate 21 is formed with a predetermined hole inside thereof, so that when the first substrate 21 is stacked on the second substrate 22, a predetermined internal space S <b> 1 is formed inside the package 20.
This internal space S1 is a cavity for accommodating the piezoelectric vibrating piece 30 and is formed in a rectangular shape in this embodiment.

  Further, the opening end surface 21a on the opening 20b side that opens upward in FIG. 2 of the first substrate 21 is made of, for example, a metal such as Kovar (Fe-Ni-Co) using a Koval seam ring 24 or the like. The lid body 26 formed of the alloy is joined, and the internal space S1 is sealed with the lid. Thus, the lid 26 is made of metal, so that it can be grounded and have a shielding effect.

The entire second substrate 22 has a flat plate shape, and mounting terminals 23 are provided at both ends in the longitudinal direction of the bottom surface as shown in FIG.
In addition, on the bottom surface exposed to the internal space S1 of the second substrate 22, that is, the inner bottom 20a of the package 20, for example, a pair of mount electrodes 28, 28 formed by nickel plating and gold plating on tungsten metallization are provided. Yes.
Each of the mount electrodes 28 and 28 is connected to the mounting terminal portions 23 and 23 on the back surface through conductive patterns 29 and 29 in via holes provided in the second substrate 22, thereby differentiating each other. Thus, an electrode for supplying a driving voltage to the piezoelectric vibrating piece 30 is obtained.

  Specifically, the mount electrodes 28 and 28 are provided at positions facing side edge portions 30c of portions where the later-described extraction electrodes 46 and 47 of the piezoelectric vibrating piece 30 are provided. Then, a conductive adhesive such as silicone, epoxy, or polyimide is applied as an adhesive 40, 40 on the mount electrodes 28, 28, and the piezoelectric vibrating piece 30 is mounted on the adhesive 40, 40. As a result, the mounting electrodes 28 and 28 and the piezoelectric vibrating piece 30 are electrically and mechanically connected. In addition, it is preferable to use the flexible silicone type conductive adhesive which can absorb the impact from the outside as the adhesives 40 and 40.

The piezoelectric vibrating piece 30 is formed of, for example, quartz or the like, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to the quartz.
The piezoelectric vibrating reed 30 is formed with substantially the same thickness D1 except for a long groove 50 described later, and has excitation electrodes 44 and 45 on the surface of the piezoelectric body, as shown in FIG. An excitation portion 30a is formed, and an extraction portion 30b having extraction electrodes 46 and 47 formed so as to extract the excitation electrodes 44 and 45 is formed.

Since the piezoelectric vibrating piece 30 of the present embodiment is erected and joined to the package 20 as will be described later, the following configuration is adopted to reduce the size (in this embodiment, 2 mm × 1.2 mm × 0). .. designed to be 6 mm), preventing overturning.
First, the piezoelectric vibrating piece 30 is a so-called tuning fork type piezoelectric vibrating piece. In other words, the pair of vibrating arms 34 and 35 extending in parallel with each other of the piezoelectric vibrating piece 30 serves as the excitation unit 30a, and the base portion that supports the pair of vibrating arms 34 and 35 serves as the extraction unit 30b.

Further, the vibrating arms 34 and 35 divided into two forks from the lead-out portion 30b are formed with long grooves 50 extending along the longitudinal direction on the front and back surfaces, respectively, and the cross section is substantially H-shaped as shown in FIG. It has become.
An excitation electrode 44 is formed in the long groove 50 of the vibrating arm 35, and an excitation electrode 45 is formed on the side surface of the vibrating arm 35 so as to face the excitation electrode 44 in the long groove 50. An excitation electrode 45 is formed in the long groove 50 of the vibrating arm 34, and the excitation electrode 44 is formed on the side surface of the vibrating arm 34 so as to face the excitation electrode 45 in the long groove 50.
The excitation electrodes 44 and 45 are electrically connected to the pair of extraction electrodes 46 and 47 drawn to the base and have different polarities. The electrodes 44, 45, 46, and 47 are connected to the side edges (approximately the crotch between the vibrating arm 34 and the vibrating arm 35, and the extraction electrode 46 and the extraction electrode) over substantially the entire circumference of the piezoelectric vibrating piece 30. 47), and the connection is made.

As a result, the electric field efficiency can be increased in the vibrating arms 34 and 35 and the crystal impedance value (CI value) can be lowered, so that the piezoelectric vibrating piece 30 can be reduced in size.
Further, although not shown in the drawing, the lead-out portion 30b that is a base portion that supports the pair of vibrating arms 34 and 35 is formed with a notch portion (not shown) facing the side surface so as to reduce the width direction. Of course, so-called vibration leakage is prevented and the piezoelectric vibrating piece 30 can be downsized.

Here, as shown in FIG. 2, the piezoelectric vibrating piece 30 has a side edge portion 30 c other than the excitation portion 30 a that is directly joined to the inner bottom 20 a of the package 20.
That is, the side edge portion 30c other than the excitation portion 30a of the piezoelectric vibrating piece 30 is disposed so as to face the inner bottom 20a of the package 20, and the side edge portion 30c and the inner bottom 20a are directly joined.

  Specifically, the extraction electrodes 46 and 47 provided on the extraction portion (base portion) 30b are side edges in the longitudinal direction of the extraction portion 30b in order to make electrical connection with the excitation electrodes 44 and 45 as described above. Also provided in the portion 30c, the lead electrodes 46, 47 and the mount electrodes 28, 28 of the side edge portion 30c in the longitudinal direction are electrically and mechanically connected by the conductive adhesives 40, 40. . For this reason, in the case of the present embodiment, the side edge portion 30c in the longitudinal direction is joined to the inner bottom 20a of the package, and the piezoelectric vibrating piece 30 has a longitudinal direction in the height direction (vertical direction in FIG. 2). It will stand up along.

  In the present embodiment, the mount electrodes 40, 40 are also provided on the surface (inner side surface exposed to the internal space S1) 20b of the package 20 in contact with the inner bottom 20a, and are in contact with the inner bottom 20a. The surface 20b and the side edge portion 30d in the width direction of the piezoelectric vibrating piece 30 are electrically and mechanically bonded by the conductive adhesive 40, so that the bonding strength of the piezoelectric vibrating piece 30 to the package 20 is improved. .

In order to accommodate such a piezoelectric vibrating piece 30, in the package 20, as shown in FIG. 2, at least one surface 20 c of the inner wall (inner side surface) exposed in the internal space S 1 is the main surface of the piezoelectric vibrating piece 30. It has an area larger than the projected area. In addition, since the internal space S <b> 1 of the present embodiment is formed in a substantially rectangular shape, two opposing surfaces of the inner wall have an area larger than the projected area of the main surface of the piezoelectric vibrating piece 30.
Specifically, as shown in FIG. 1 and FIG. 2, the longest side of the main surface of the piezoelectric vibrating piece 30 is the length L1, and the vertical direction of the main surface with respect to the length L1 is the width W1. When the thickness is D1, the height H2 of the internal space S1 of the package 20 is larger than the length L1 of the piezoelectric vibrating piece 30, the width W2 of the internal space S1 is larger than the width W1 of the piezoelectric vibrating piece 30, and the inner space S1 The depth D2 is formed larger than the thickness D1 of the piezoelectric vibrating piece 30.

  The first embodiment of the present invention is configured as described above, and the side edge portion 30 c of the piezoelectric vibrating piece 30 is directly joined to the inner bottom 20 a of the package 20. For this reason, the inner bottom 20a of the package 20 only needs to have a size corresponding to the area of the side edge portion 30c that is significantly smaller than the area of the main surface of the piezoelectric vibrating piece 30. Even if the piezoelectric vibrating piece 30 is reduced in size, it can be joined to the package 20 side by effectively utilizing the side edge 30c. Further, since the portion of the piezoelectric vibrating piece 30 bonded to the package 20 is the side edge portion 30c other than the excitation portion 30a, there is little adverse effect on the vibration characteristics of the piezoelectric vibrating piece 30. Therefore, the mounting area of the piezoelectric device 10 using the miniaturized piezoelectric vibrating piece 30 can be significantly reduced.

4 and 5 show the piezoelectric device 12 according to the second embodiment of the present invention. FIG. 4 is a schematic plan view of the piezoelectric device 12 (that is, when the piezoelectric device 12 is connected to the mounting substrate, FIG. FIG. 5 is a schematic sectional view taken along the line CC of FIG.
In addition, the part of the parallel oblique line of FIG. 5 is shown for the convenience of understanding, Comprising: A cross section etc. are not represented.

In these drawings, the portions denoted by the same reference numerals as those used in the description of FIGS. 1 to 3 have a common configuration, and therefore, a duplicate description will be omitted, and hereinafter, differences will be mainly described.
The piezoelectric device 12 is mainly different from the piezoelectric device 10 shown in FIGS. 1 to 3 in the bonding structure of the piezoelectric vibrating piece 30 to the package.

  That is, the piezoelectric vibrating piece 30 of the piezoelectric device 12 is formed with a fixed arm 32 to be joined to the package 20 so as to extend the extraction portion 30b which is a region other than the excitation portion 30a. Is directly joined to the package 20 side so that the side edge portion 32a faces the inner bottom 20a of the package.

Specifically, the fixed arm 32 is integrally formed on the same surface as the drawing portion 30b, and has a length that allows the adhesive to be applied so that the posture of the piezoelectric vibrating piece 30 can be reliably held. The length is preferably longer than the length of the portion 30a. In the case of the present embodiment, the length is the same as the entire length of the piezoelectric vibrating piece 30.
As described above, the piezoelectric vibrating piece 30 is formed with a fixed arm 32 for joining to the package 20 separately from the excitation unit 30a and the extraction unit 30b, so that the portion other than the side edge portion of the piezoelectric vibrating piece 30 is formed. Also, the bonding strength of the piezoelectric vibrating piece 30 to the package 20 is increased.

The fixed arm 32 extends from the position of the end 30c farthest from the excitation part 30a of the extraction part 30b (in the present embodiment, near the corner at the end opposite to the excitation part 30a of the extraction part 30b). Thus, it is formed along the longitudinal direction of the piezoelectric vibrating piece 30 so as to face the side edge of the excitation unit 30a.
As described above, the fixed arm 32 is disposed so as to be away from the excitation unit 30a that actively participates in the vibration, thereby making it difficult to transmit the vibration of the excitation unit 30a to the package 20, and also the vibration and conductivity on the package 20 side. It is difficult to transmit the stress of the adhesive 40 to the excitation unit 30a.

  Furthermore, it is more preferable that the fixed arm 32 has a structure in which both sides 32-1 and 32-2 are joined to the package 20 around a virtual line CL <b> 1 in the width direction passing through the center of gravity OP of the piezoelectric vibrating piece 30. Thereby, the piezoelectric vibrating piece 30 can be held on the package 20 in a stable posture.

In addition, in the case of this embodiment, the mounting arm on the side of the package 20 is such that the extraction electrodes 46 and 47 extend to a portion joined to the package 20 of the fixed arm 32, that is, in the case of the present embodiment, the outer side edge portion 32a. A pair of connection electrodes 48 and 49 that are electrically and mechanically connected to the electrodes 28 and 28 are provided.
A groove 52 is formed between the pair of polarized electrodes 48 and 49 of the connection electrodes 48 and 49. The groove 52 is disposed so as to prevent contact between the adhesive 40 attached to the electrode 48 and the adhesive 40 attached to the electrode 49. In the present embodiment, the groove 52 is formed on the side edge 32 a of the fixed arm 32. A concave groove is formed. This prevents a short circuit between the connection electrode 48 and the connection electrode 49.

  The pair of polarized electrodes of the extraction electrodes 46 and 47 and the connection electrodes 48 and 49 have substantially the same area. That is, among the electrodes having different polarities, the extraction electrode 46, the connection electrode 48 formed integrally with the extraction electrode 46, the extraction electrode 47 and the connection electrode 49 formed integrally with the extraction electrode 47, Are provided on the surface of the piezoelectric body with substantially the same area. Thereby, the mutual electric capacity is made the same, and the voltage is supplied to the excitation unit 30a in a balanced manner.

Furthermore, the piezoelectric vibrating piece 30 of the second embodiment has a protruding portion 54 that protrudes from the lead-out portion 30b toward the opening 20b side of the package 20 when bonded to the package 20 side. .
The protruding portion 54 is a portion used when the piezoelectric vibrating piece 30 is mounted. For example, the collet is brought into contact with the side edge portion 54 a outside the protruding portion 54 and is adsorbed. For this reason, when the piezoelectric vibrating piece 30 is mounted, if the protrusion 54 is sucked and held, the opening 20b of the package 20 is narrow and the collet cannot be inserted into the package 20. Even if it exists, the piezoelectric vibrating piece 30 can be joined to the package 20 accurately.

Specifically, when the piezoelectric vibrating piece 30 is joined to the inner bottom 20a of the package 20, the protruding portion 54 is formed on the side edge portion 54a outside the protruding portion 54 in the height direction (vertical direction in FIG. 5). The position is formed so as to be substantially the same as the position of the end surface 21 a on the opening 20 b side of the package 20.
Further, the projecting portion 54 is an end portion farthest from the excitation portion 30a of the extraction portion 30b (in this embodiment, near the corner portion of the end portion on the opposite side of the excitation portion 30a of the extraction portion 30b), and the central axis Is formed so as to protrude from the end opposite to the fixed arm 32 side. The protruding portion 54 extends along the longitudinal direction of the piezoelectric vibrating piece 30 and preferably extends so as to be disposed on a virtual line CL1 in the width direction passing through the center of gravity OP of the piezoelectric vibrating piece 30. ing.

The second embodiment of the present invention is configured as described above, and the fixed arm 32 joined to the package 20 of the piezoelectric vibrating piece 30 has a side edge portion 32 a facing the inner bottom 20 a of the package 20. Thus, it is directly joined to the package 20. For this reason, since the inner bottom 20a of the package 20 that accommodates the piezoelectric vibrating piece 30 only needs to be formed corresponding to the area of the side edge portion 32a of the opposing piezoelectric vibrating piece 30, the mounting area can be greatly reduced. it can.
Further, by forming the fixed arm 32 for joining to the package 20 in this way, even if an adhesive is applied to the side edge portion 32a of the fixed arm 32 and the portion in contact with the side edge portion 32a. There is no problem, and the piezoelectric vibrating piece 30 can be reliably bonded to the package 20.

  As described above, a so-called tuning fork type piezoelectric vibrating piece is used for the piezoelectric vibrating piece 30 of the present embodiment, but the present invention is not limited to such a piezoelectric vibrating piece. As shown in FIG. 6, it may be a so-called AT-cut vibrating piece, or a SAW resonator or the like.

FIG. 7 is a schematic perspective view of a piezoelectric device 14 according to a modification of the second embodiment of the present invention. For convenience of understanding, the electrode on the piezoelectric vibrating piece is not shown.
In this figure, the portions denoted by the same reference numerals as those used in the description of FIGS. 1 to 6 have the same configuration, and therefore, a duplicate description will be omitted, and hereinafter, differences will be mainly described.
This piezoelectric device 14 differs from the piezoelectric devices 10 and 12 of FIGS. 1 to 6 only in the structure of the package.

That is, the package 20 of the piezoelectric device 14 is formed so that a plurality of substrates are stacked in the horizontal direction and in the thickness D1 direction of the piezoelectric vibrating piece 30.
Specifically, the package 20 includes a frame-like substrate 61 having an opening having an area larger than the projected area of the main surface of the piezoelectric vibrating piece 30 and a substantially flat plate-like substrate 60 in a horizontal direction. In this case, the piezoelectric vibrating reed 30 is formed by overlapping in the direction of the thickness D1.
Then, after mounting the piezoelectric vibrating piece 30, the opening of the frame-shaped substrate 61 (which becomes the opening of the package 20) is sealed (the internal space S 1 is sealed) with a substrate 62 that transmits light such as glass. I am doing so. For this reason, the substrate 62 that transmits light is disposed on the side surface of the package 20 that faces the main surface of the piezoelectric vibrating piece 30.

The modification of the second embodiment of the present invention is configured as described above, and the substrate 62 that transmits light is disposed on the side surface of the package 20 that faces the main surface of the piezoelectric vibrating piece 30. Even after the internal space S1 is sealed, the frequency is adjusted by a mass reduction method by irradiating a metal coating portion such as an excitation electrode (not shown) of the piezoelectric vibrating piece 30 with the laser beam LB from the side surface side. Can do.
Moreover, since the opening of the package 20 is formed at least larger than the projected area of the main surface of the piezoelectric vibrating piece 30, the piezoelectric vibrating piece 30 can be easily inserted into the package 20. Therefore, it is not necessary to provide the protrusion 54 unlike the piezoelectric vibrating piece 30 of FIG. 5, and the height of the package 20 can be suppressed.

  The present invention is not limited to the above-described embodiment. Each configuration of the embodiment and each modified example can be appropriately combined or omitted, and can be combined with other configurations not shown.

1 is a schematic plan view of a piezoelectric device according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line AA in FIG. 1. FIG. 3 is an end view taken along line B-B in FIG. 2. The schematic plan view of the piezoelectric device which concerns on the 2nd Embodiment of this invention. CC sectional schematic sectional drawing of FIG. The other example of the piezoelectric device which concerns on the 2nd Embodiment of this invention. The schematic perspective view of the piezoelectric device which concerns on the modification of the 2nd Embodiment of this invention. The schematic longitudinal cross-sectional view of the conventional piezoelectric device. The longitudinal cross-sectional view which showed the other example of the conventional piezoelectric device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 12, 14 ... Piezoelectric device, 20 ... Package, 20a ... Inner bottom, 30 ... Piezoelectric vibrating piece, 30a ... Excitation part, 30b ... Lead-out part, 32 ... Fixed arm, 30c, 32a ... side edge, 44, 45 ... excitation electrode, 46, 47 ... extraction electrode

Claims (8)

A piezoelectric vibrating reed bonding structure for bonding a piezoelectric vibrating reed having an excitation electrode formed on the surface of a piezoelectric body to the package side,
The piezoelectric vibrating piece joining structure, wherein a side edge portion of the piezoelectric vibrating piece other than the excitation portion is directly joined to the inner bottom side of the package. A piezoelectric vibrating reed bonding structure for bonding a piezoelectric vibrating reed having an excitation electrode formed on the surface of a piezoelectric body to the package side,
A fixed arm to be joined to the package is formed so as to extend from a region other than the excitation part of the piezoelectric vibrating piece,
This fixed arm is directly joined to the package side with its side edge facing the inner bottom of the package. The piezoelectric vibrating piece joining structure according to claim 1, wherein: An extraction electrode is provided on the surface of the piezoelectric body so as to extract the excitation electrode,
The pair of connection electrodes connected to the electrode on the package side are provided at the portion of the fixed arm that is joined to the package so as to extend the extraction electrode. The piezoelectric vibrating piece joining structure according to 1.   The piezoelectric vibrating piece joining structure according to claim 3, wherein the pair of polarized electrodes of the extraction electrode and the connection electrode have substantially the same area.   5. The piezoelectric vibrating piece joining structure according to claim 3, wherein a groove is formed between a pair of polarized electrodes of the connection electrode.   6. The piezoelectric vibrating piece according to claim 1, further comprising a projecting portion projecting from a region other than the excitation portion toward the opening side of the package when bonded to the package side. Bonding structure of the described piezoelectric vibrating piece. A piezoelectric device including a piezoelectric vibrating piece in which an excitation unit having an excitation electrode is formed on a surface of a piezoelectric body, and a package configured to accommodate the piezoelectric vibrating piece,
A side edge portion other than the excitation portion of the piezoelectric vibrating piece is directly joined to the inner bottom side of the package. A piezoelectric device including a piezoelectric vibrating piece in which an excitation electrode is provided on a surface of a piezoelectric body and an excitation portion is formed, and a package that accommodates the piezoelectric vibrating piece,
A fixed arm to be joined to the package is formed so as to extend from a region other than the excitation part of the piezoelectric vibrating piece,
The piezoelectric device is characterized in that the fixed arm is directly joined to the package side such that a side edge thereof faces the inner bottom of the package.

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