JP3894284B2 - Piezoelectric device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piezoelectric device in which a tuning fork type piezoelectric vibrating piece is built in a package.
[0002]
[Prior art]
In recent years, miniaturization and thinning of devices have been remarkable in small information devices such as HDDs (hard disk drives), mobile computers, and IC cards, and mobile communication devices such as mobile phones, car phones, and paging systems. Piezoelectric devices used in the industry are also required to be small and thin.
In addition, there is a need for a surface-mount type piezoelectric device that can be mounted on both sides of the circuit board of the apparatus.
[0003]
[Problems to be solved by the invention]
FIG. 14 is a schematic plan view showing a configuration example of a piezoelectric device that is being prototyped under such a demand for miniaturization, and FIG. 14A is a schematic diagram showing a configuration of a small piezoelectric device. Sectional drawing and FIG.14 (b) are the figures which expand and show the part A of Fig.14 (a).
Referring to FIG. 14, a piezoelectric device 1 whose prototype is being considered contains a piezoelectric vibrating piece 2 inside a package 6. The piezoelectric vibrating piece 2 is formed using a quartz substrate, for example. The piezoelectric vibrating reed 2 is formed in a tuning fork type having a base 11 joined to an electrode portion of the package 6 and a pair of vibrating arms 4 and 5 extending in parallel from the base 11, and a driving for driving (not shown) is formed on the surface thereof. A metal electrode is formed.
[0004]
The package 6 is formed by laminating a plurality of ceramic substrates to form a predetermined internal space S inside. In the internal space S, the base 11 of the piezoelectric vibrating reed 2 described above is bonded and fixed to the electrode portions 3 and 3 via the conductive adhesive 7 or the like at the bottom inside the package 6. The tip of the vibrating piece 2 is a free end.
A lid 9 formed of a material that transmits light, such as glass, that is, a light-transmitting material, is joined to the open upper end of the package 6 via a brazing material such as low-melting glass. It is sealed by.
[0005]
The piezoelectric device 1 is configured as described above. When an external driving voltage is transmitted to the piezoelectric vibrating piece 2 via the electrode unit 3 and the conductive adhesive 7, the piezoelectric vibrating piece 2 is not illustrated. When the voltage from the excitation electrode is transmitted to the piezoelectric material, the pair of vibrating arms 4 and 5 generate bending vibration and vibrate at a predetermined frequency.
By extracting the predetermined frequency to the outside, an output with the predetermined frequency can be obtained.
[0006]
Here, the piezoelectric device 1 uses, for example, a tuning-fork type piezoelectric vibrating piece 2 as shown in FIG. 14A to set the dimensions shown in FIG. ing.
In the figure, the total length a of the package 6 is 3.20 mm, the total width b of the package 6 is 1.50 mm, the total length d of the piezoelectric vibrating piece 2 is 2.20 mm, and the distance c between the base 11 of the piezoelectric vibrating piece 2 and the inner wall of the package 6 Is 0.1 mm, and the distance e between the tips of the vibrating arms 4 and 5 of the piezoelectric vibrating piece 2 and the inner wall of the package 6 is 0.1 mm.
[0007]
Thus, when the piezoelectric vibrating reed 2 is joined in the package 6 of the miniaturized piezoelectric device 1, as described above, on the electrode portions 3 and 3 formed on the inner bottom portion of the package 6, Applying the conductive adhesives 7 and 7, placing the base 11 of the piezoelectric vibrating reed 2 thereon, pressing lightly from above, spreading the conductive adhesives 7 and 7 under the base 11, and then curing. I have to.
[0008]
However, such a bonding / fixing operation of the piezoelectric vibrating piece 2 has the following problems.
FIG. 15 shows a region where the piezoelectric vibrating piece 2 is fixed, and is an enlarged plan view showing an upper portion of the base 11 of the piezoelectric vibrating piece 2 in FIG.
When the piezoelectric vibrating reed 2 is accommodated in the package 6 and is to be fixed securely, a relatively large amount of the conductive adhesive 7 is applied on the electrode part 3, and the base part 11 is placed on the conductive part 7 to conduct electricity. The adhesive 7 is cured.
In the case of FIG. 15, the piezoelectric vibrating reed 2 is firmly fixed on the electrode part 3 by a large amount of conductive adhesive 7, and even when an external impact is applied to the piezoelectric device 1, it is difficult to break. There are advantages.
[0009]
However, when a large amount of the conductive adhesive 7 is applied, as shown in FIG. 15, the conductive adhesive 7 spreads sideways, and not only the entire base portion 11 but also between the base portion 11 and the widened portion 12 near the base end of the vibrating arm 4. In some cases, the conductive adhesive 7 may wrap around to the notch 13 present in the area.
Here, the notch 13 is provided so that the vibration from the vibrating arm 4 does not easily leak into the base 11, and the conductive adhesive 7 wraps around the notch 13 and vibrates as shown in the figure. If the portion close to the arm 4 is fixed with the conductive adhesive 7, the original function of the cutout portion 13 may be hindered after fixing, and the CI (crystal impedance) value may be increased.
[0010]
In order to avoid such a situation, the amount of the conductive adhesive 7 is limited and, for example, a small amount of the conductive adhesive 7 is set so as to be in a range corresponding to the vicinity of the center of the base portion 11 as indicated by parallel oblique lines in FIG. When the adhesive 7 is applied on the electrode part 3 and the base part 11 is placed from above and pressed lightly, the state shown in FIG. 16 may be obtained.
[0011]
That is, FIG. 16 shows the relationship between the bottom surface 11 b of the base portion 11 of the piezoelectric vibrating piece 2 and the conductive adhesive 7. Even if a small amount of the conductive adhesive 7 is pressed from above by the base portion 11, May not wrap around the entire bottom surface 11 b of the base 11.
In particular, as shown in FIGS. 14B and 15, both corners on the end 11 c side of the base 11 are formed at right angles, and therefore, the conductive adhesive 7 is provided at the corners. A gap or notch 14 is formed without wrapping around.
Since the location of the gap 14 is not fixed by the conductive adhesive 7, when an impact is applied to the piezoelectric device 1 from the outside, stress is concentrated and may be destroyed.
[0012]
An object of the present invention is made to solve the above-described problem, and even when configured in a small size, the piezoelectric vibrating piece is firmly fixed, so that a piezoelectric device having excellent impact resistance; It is an object of the present invention to provide a mobile phone device and an electronic device using this device.
[0013]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a piezoelectric device having a package in which a tuning fork type piezoelectric vibrating piece is fixed in a cantilever manner and accommodated therein, and a lid fixed to the package. The tuning fork type piezoelectric vibrating piece includes a base fixed to the package side and a pair of vibrating arms extending in parallel from the base, and the base end of the vibrating arm and the base has a cutout portion between, both widthwise end portions of the vibrating arm opposite said base portion, is curvilinear or chamfered shape, the electrodes of the base portion of the bottom surface and the package of the piezoelectric vibrating reed The conductive adhesive applied between the parts is achieved by the piezoelectric device applied inside the notch .
According to the configuration of the first aspect, since both ends in the width direction on the opposite side of the vibrating arm of the base of the piezoelectric vibrating piece are curved or chamfered, a corner portion is formed in the region on the bottom of the base. Does not exist. For this reason, even when a relatively small amount of conductive adhesive is used, the adhesive adheres to the entire bottom surface of the base.
For this reason, since there is no gap at the bottom of the corner corner without the conductive adhesive adhering, there is no place where stress is concentrated due to an impact from the outside, and an area that is easily broken is not formed. The piezoelectric vibrating piece is firmly fixed.
Since the piezoelectric vibrating piece can be firmly fixed with a relatively small amount of conductive adhesive, a large amount of conductive adhesive is not used and the conductive adhesive does not reach the notch. The increase in CI value can be effectively prevented without inhibiting the function of the notch.
Here, the piezoelectric device widely includes piezoelectric elements in which a piezoelectric vibrating piece is accommodated in a package such as a piezoelectric vibrator or a piezoelectric oscillator.
[0014]
The invention of claim 2 is characterized in that, in the configuration of claim 1, both end portions in the width direction opposite to the vibrating arm of the base are formed in a curved shape including a part of an ellipse or an ellipse. To do.
According to the configuration of the second aspect, since both ends in the width direction opposite to the vibrating arm of the base portion of the piezoelectric vibrating piece are formed in a curved shape including a part of an ellipse or an ellipse. As in the case of, there are no corners at this location, and there is no gap where the conductive adhesive does not adhere.
[0017]
According to a third aspect of the present invention, there is provided a package in which a tuning fork type piezoelectric vibrating piece is fixed in a cantilever manner and accommodated therein, and a lid fixed to the package. A piezoelectric device, wherein the tuning-fork type piezoelectric vibrating piece includes a base portion fixed to a package side and a pair of vibrating arms extending in parallel from the base portion, and at least a side of the base opposite to the vibrating arm. Both ends in the width direction have an inclination inward toward the bottom surface , and have a notch between the base end of the vibrating arm and the base, and the base of the piezoelectric vibrating piece This is achieved by a piezoelectric device characterized in that a conductive adhesive applied between the bottom surface of the package and the electrode part of the package is applied inside the notch .
According to the configuration of the third aspect , since the bottom surfaces of both end portions in the width direction of the base portion of the piezoelectric vibrating piece have an inward slope, the base portion is placed on the conductive adhesive. Even when a relatively small amount of the conductive adhesive is used, the conductive adhesive wraps around along this inclination, so that there is no gap where the conductive adhesive does not adhere. For this reason, since there is no gap at the bottom of the corner corner without the conductive adhesive adhering, there is no place where stress is concentrated due to an impact from the outside, and an area that is easily broken is not formed. The piezoelectric vibrating piece is firmly fixed.
[0018]
According to this configuration, since the piezoelectric vibrating piece can be firmly fixed with a relatively small amount of the conductive adhesive, a large amount of the conductive adhesive is not used. Therefore, an increase in CI value can be effectively prevented without inhibiting the function of the notch.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B show a first embodiment of a piezoelectric device according to the present invention. FIG. 1A is a schematic plan view thereof, and FIG. 1B is a schematic cross-sectional view taken along line AA of FIG. FIG.
In these drawings, the piezoelectric device 30 shows an example in which a piezoelectric vibrator is configured. The piezoelectric device 30 houses a piezoelectric vibrating piece 32 in a package 36. The package 36 is formed, for example, by laminating a plurality of substrates using an aluminum oxide sintered body formed by sintering a ceramic green sheet. Each of the plurality of substrates is formed with a predetermined hole on the inner side thereof so that a predetermined inner space S is formed on the inner side when stacked.
[0023]
In the inner space S of the package 36, in the vicinity of the left end portion, electrode portions 31 and 31 plated with Au and Ni are provided on the laminated substrate that is exposed to the inner space S and forms the bottom, as shown in FIG. As shown to (a), it forms at predetermined intervals. The electrode parts 31, 31 are connected to the outside and supply a driving voltage. Conductive adhesives 43, 43 are applied on the electrode portions 31, 31, and the base 51 of the piezoelectric vibrating piece 32 is placed on the conductive adhesives 43, 43, so that conductive adhesion is achieved. The agents 43 and 43 are bonded by being cured.
[0024]
In the present embodiment, as will be described later, the piezoelectric vibrating reed 32 can be firmly fixed even when a relatively small amount of the conductive adhesives 43 are used.
An extraction electrode (not shown) for transmitting a driving voltage is formed on a portion of the base 51 of the piezoelectric vibrating piece 32 that comes into contact with the conductive adhesives 43, 43. The driving electrodes to be connected are electrically connected to the electrode portions 31 and 31 on the package 36 side via the conductive adhesives 43 and 43.
[0025]
The piezoelectric vibrating piece 32 is formed of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to quartz. In the case of the present embodiment, the piezoelectric vibrating piece 32 has a particularly illustrated shape in order to form a small size and obtain necessary performance.
That is, the piezoelectric vibrating piece 32 is preferably bundled by shrinking partly from both sides at a base 51 fixed to the package 36 as will be described later and one end of the base 51. And the widened portions 52 and 52, which are regions formed wider than the cutout portions 53 and 53. Further, the piezoelectric vibrating piece 32 includes a pair of vibrating arms 34 and 35 extending in parallel to be divided into two forks to the right in the drawing with the widened portions 52 and 52 as the base ends, and the whole is a tuning fork. A so-called tuning fork type piezoelectric vibrating piece having such a shape is used.
Thereby, especially in the piezoelectric vibrating piece 32 of this embodiment, the vibration of the pair of vibrating arms 34 and 35 is prevented from leaking as much as possible with respect to the base 51 on the fixed side. The CI value is reduced as much as possible.
[0026]
The upper end of the package 36 is sealed by bonding a lid 39 via a brazing material 33 such as low melting point glass. The lid 39 is formed of a material that transmits light, for example, glass, in order to perform frequency adjustment described later.
[0027]
In addition, an opening 37 is provided near the center of the bottom surface of the package 36 by forming through holes 37 a and 37 b that are continuous with two laminated substrates (not shown) constituting the package 36. Of the two through-holes constituting the opening 37, the outer through-hole 37b, which is the second hole, has a larger inner diameter than the first hole 37a opened inside the package. . Thereby, the opening 37 is a stepped opening, and preferably, the step portion of the through hole 37b, which is the second hole, and the inner peripheral surface of the through hole 37a are covered with metal.
The opening 37 is filled with a metal sealing material 38 so that the lid 39 can be sealed after being fixed to the package 36.
As the metal sealing material 38 filled in the opening 37, for example, an alloy of gold (Au) and tin (Sn) is used, and the step portion of the second hole 37a and the metal covering portion on the inner peripheral surface of the hole are used. For this, a structure in which a gold plating is coated on a base layer made of nickel plating is suitable.
[0028]
Further, in this embodiment, a recess 42 corresponding to the thickness of the multilayer substrate is formed in the lowermost substrate of the multilayer substrate constituting the package 36 by forming a hole near the right end in the figure. . The recess 42 is located below the free end 32 b of the piezoelectric vibrating piece 32. This effectively prevents the package 36 from coming into contact with the inner bottom surface when the free end 32b of the piezoelectric vibrating piece 32 swings in the direction of the arrow when an external impact is applied to the package 36. .
[0029]
Next, the configuration of the base 51 of the piezoelectric vibrating piece 32 in the present embodiment will be described in detail.
FIG. 2 shows an enlarged portion B of FIG.
In the drawing, at the end 51a of the base 51 of the piezoelectric vibrating piece 32, both ends 57, 57 in the width direction are curved. The curved portions correspond to the end portions in the length direction at both end portions in the width direction of the base portion 51 as indicated by reference numerals 57 and 57 in FIG.
[0030]
Therefore, there are no corners that project at an acute angle or a right angle at both ends in the length direction of the base 51 and at both ends in the width direction. Therefore, as shown in FIG. 3, even when a relatively small amount of the conductive adhesive 43 is used, the conductive adhesive 43 adheres to the entire bottom surface 51 b of the base 51.
As a result, the conductive adhesive 43 does not adhere and no gap is formed at the bottom of the corner, so there is no portion where stress is concentrated due to an impact from the outside, and a region that is easily broken is not formed. The piezoelectric vibrating piece 32 is firmly fixed.
[0031]
In addition, since the piezoelectric vibrating piece 32 can be firmly fixed with a relatively small amount of the conductive adhesive 43, the conductive adhesive 43 does not cut the piezoelectric vibrating piece 32 without using a large amount of the conductive adhesive 43. Since the notch 53 is not reached, the increase of the CI value can be effectively prevented without inhibiting the function of the notch 53.
[0032]
FIG. 4 is a schematic plan view showing a second embodiment of the piezoelectric device of the present invention. In the figure, the same reference numerals as those in the first embodiment are used in common, and therefore, overlapping description will be omitted, and differences will be mainly described.
[0033]
The piezoelectric device 60 according to the second embodiment has the same configuration as that of the first embodiment except for the shape of the base 51 of the piezoelectric vibrating piece 32.
FIG. 5 is an enlarged view of a portion C in FIG. As shown in the drawing, the end portion in the length direction of the base portion 51 and both end portions in the width direction (one end portion is shown in FIG. 5 and the structure of the other end portion is the same) 56 are linear. It is chamfered diagonally.
[0034]
Therefore, in the case of the second embodiment as well, there are no corners that protrude in an acute angle or a right angle at both ends in the length direction of the base 51 and at both ends in the width direction. Therefore, as in the case described with reference to FIG. 3, even when a relatively small amount of the conductive adhesive 43 is used, the conductive adhesive 43 adheres to the entire bottom surface of the base portion 51.
As a result, the conductive adhesive 43 does not adhere and no gap is formed at the bottom of the corner, so there is no portion where stress is concentrated due to an impact from the outside, and a region that is easily broken is not formed. The piezoelectric vibrating piece 32 is firmly fixed.
[0035]
FIG. 6 is a schematic plan view showing a third embodiment of the piezoelectric device of the present invention. In the figure, the same reference numerals as those in the first embodiment are used in common, and therefore, overlapping description will be omitted, and differences will be mainly described.
[0036]
In the piezoelectric device 70 according to the third embodiment, all except the point that the shape of the package 76 is slightly longer than the shape of the package 36 of the first embodiment and the shape of the base 51 of the piezoelectric vibrating piece 32 are all the first. This is the same configuration as the embodiment.
FIG. 7 is an enlarged view of a portion D in FIG. As shown in the drawing, both side surfaces 71 including end portions in the length direction of the base portion 51 and both end portions in the width direction (one end portion is shown in FIG. 7 and the other end portion has the same structure). Is formed in a curved shape including a part of an ellipse or an ellipse.
[0037]
Accordingly, in the case of the third embodiment as well, there are no corners that project at an acute angle or a right angle on both side surfaces 71 and 71 at the end in the length direction of the base 51 and including both ends in the width direction. . Therefore, as in the case described with reference to FIG. 3, even when a relatively small amount of the conductive adhesive 43 is used, the conductive adhesive 43 adheres to the entire bottom surface of the base portion 51.
As a result, the conductive adhesive 43 does not adhere and no gap is formed at the bottom of the corner, so there is no portion where stress is concentrated due to an impact from the outside, and a region that is easily broken is not formed. The piezoelectric vibrating piece 32 is firmly fixed.
[0038]
FIG. 8 is a schematic plan view showing a fourth embodiment of the piezoelectric device of the present invention. In the figure, the same reference numerals as those in the first embodiment are used in common, and therefore, overlapping description will be omitted, and differences will be mainly described.
[0039]
The piezoelectric device 80 according to the fourth embodiment has the same configuration as that of the first embodiment except for the shape of the base 51 of the piezoelectric vibrating piece 32.
FIG. 9 is an enlarged view of a portion E in FIG. As shown in the drawing, the end portion in the length direction of the base portion 51 and both end portions in the width direction (one end portion is shown in FIG. 9 and the other end portion has the same structure) 81 are shown in FIG. The shape is as shown in FIG.
[0040]
FIG. 10 is a partially enlarged perspective view showing the shape of the both ends 81 and 81 in the width direction described above with the bottom surface 51b of the base 51 facing upward.
As shown in the drawing, both end portions 81, 81 in the width direction of the base 51 are provided with inclined surfaces 82, 82 having an inclination inward toward the bottom surface.
Here, each of the inclined surfaces 82 and 82 in FIG. 10 may be configured not only as a flat inclined surface but also as a curved surface that slightly protrudes outward or slightly concaves inside.
[0041]
The present embodiment is configured as described above, and the base 51 is placed on the conductive adhesive 43 as shown in the partial cross-sectional view along the line aa in FIG. When lightly pressed, even when a relatively small amount of the conductive adhesive 43 is used, the conductive adhesive 43 wraps around the inclined surfaces 82 and 82, so that there is no gap where the conductive adhesive 43 does not adhere.
As a result, the conductive adhesive 43 does not adhere and no gap is formed at the bottom of the corner, so there is no portion where stress is concentrated due to an impact from the outside, and a region that is easily broken is not formed. The piezoelectric vibrating piece 32 is firmly fixed.
[0042]
FIG. 12 is a schematic cross-sectional view showing the configuration of the fifth embodiment of the piezoelectric device of the present invention.
In the figure, the piezoelectric device 90 shows an example in which a piezoelectric oscillator is formed by using the piezoelectric vibrating piece 32, and the portions denoted by the same reference numerals as those in the first embodiment have a common configuration. The description will be omitted, and the difference will be mainly described.
[0043]
In the package 91 of the piezoelectric device 90, a recess 92 is formed near the center, and an electrode (not shown) is provided on the inner bottom. On this electrode, an integrated circuit 93 is mounted. The integrated circuit 93 constitutes a predetermined frequency dividing circuit and the like, and is electrically connected to the drive electrode of the piezoelectric vibrating piece 32. The output drive voltage is applied to the piezoelectric vibrating piece 32.
Further, at the end in the length direction of the base portion 51 of the piezoelectric vibrating piece 32 and at both end portions 94 and 94 in the width direction, the same configuration as that in the first to fourth embodiments is selectively used. Has been adopted.
[0044]
This embodiment is configured as described above, and in the piezoelectric device 90 which is a piezoelectric oscillator, as in the first to fourth embodiments, the conductive property is formed on the bottom surface of the base 51 of the piezoelectric device 32. Since the adhesive 43 does not adhere and no gap is formed on the bottom surface of the corner portion, there is no portion where stress is concentrated due to an impact from the outside, and no fragile region is formed. Is firmly fixed.
[0045]
FIG. 13 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the piezoelectric device according to the above-described embodiment of the present invention.
In the figure, a microphone 308 for receiving the voice of the sender and a speaker 309 for outputting the received content as a voice output are provided, and further, an integrated circuit or the like as a control unit connected to the modulation and demodulation unit of the transmission / reception signal. A controller 301 is provided.
In addition to modulation and demodulation of transmission / reception signals, the controller 301 controls an information input / output unit 302 including an LCD as an image display unit, an operation key for inputting information, an information storage unit 303 including a RAM, a ROM, and the like. Is supposed to do. For this reason, the piezoelectric device 30 is attached to the controller 301, and the output frequency is used as a clock signal suitable for the control content by a predetermined frequency dividing circuit (not shown) built in the controller 301. Has been. The piezoelectric device 30 attached to the controller 301 may be a piezoelectric device 60 as shown in FIG. 12, which is an oscillator combining the piezoelectric device 30 and a predetermined frequency dividing circuit, etc. Good.
[0046]
The controller 301 is further connected to a temperature compensated crystal oscillator (TCXO) 305, and the temperature compensated crystal oscillator 305 is connected to the transmission unit 307 and the reception unit 306. As a result, even if the basic clock from the controller 301 fluctuates when the environmental temperature changes, it is corrected by the temperature compensated crystal oscillator 305 and supplied to the transmission unit 307 and the reception unit 306.
[0047]
As described above, by using the piezoelectric device according to the above-described embodiment in an electronic device such as the mobile phone device 300 including the control unit, the piezoelectric vibrating piece of the piezoelectric device is firmly fixed. The entire device can also have excellent impact resistance.
[0048]
The present invention is not limited to the above-described embodiment. As long as the configuration of the length direction end portion of the base portion 51 of the piezoelectric vibrating piece 32 and the width direction both end portions can wrap around the conductive adhesive, various forms other than the above-described forms are adopted. it can. In addition, each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.
[0049]
【The invention's effect】
As described above, according to the present invention, a piezoelectric device having excellent impact resistance by firmly fixing a piezoelectric vibrating piece even when configured in a small size, and a mobile phone device using this device In addition, an electronic device can be provided.
[Brief description of the drawings]
1A and 1B show a first embodiment of a piezoelectric device of the present invention, in which FIG. 1A is a schematic plan view thereof, and FIG. 1B is a schematic cross-sectional view taken along line AA in FIG.
FIG. 2 is an enlarged view of a portion B in FIG.
3 is a schematic cross-sectional view showing the vicinity of the bottom surface at both ends in the width direction of the base of the piezoelectric vibrating piece of the piezoelectric device of FIG. 1;
FIG. 4 is a schematic plan view of a second embodiment of the piezoelectric device of the present invention.
5 is an enlarged view of a portion C in FIG.
FIG. 6 is a schematic plan view of a third embodiment of the piezoelectric device of the present invention.
7 is an enlarged view of a part D in FIG.
FIG. 8 is a schematic plan view of a fourth embodiment of the piezoelectric device of the present invention.
9 is an enlarged view of a portion E in FIG.
10 is a partial schematic perspective view showing the shape of the vicinity of the bottom surface of the base portion of the piezoelectric vibrating piece of the piezoelectric device of FIG. 8;
11 is a partial cross-sectional view taken along line aa in FIG.
FIG. 12 is a schematic cross-sectional view showing a configuration of a fifth embodiment of a piezoelectric device of the present invention.
FIG. 13 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using a piezoelectric device according to each embodiment of the invention.
14A and 14B show a configuration of a prototype example of an ultra-small piezoelectric device, where FIG. 14A is a schematic plan view thereof, and FIG. 14B is an enlarged view of a portion A in FIG.
15 is an explanatory diagram showing a state in which a piezoelectric vibrating piece of the piezoelectric device of FIG. 14 is bonded.
16 is a partial cross-sectional view showing a state of adhesion near the bottom of the base of the piezoelectric vibrating piece of the piezoelectric device of FIG.
[Explanation of symbols]
30, 60, 70, 80, 90 Piezoelectric device 32 Piezoelectric vibrating piece 51 Base 51a End 36, 76 Package 37 Opening 38 Sealing material 39 Lid 42 Recess

Claims (3)

A piezoelectric device having a package in which a tuning fork-type piezoelectric vibrating piece is fixed in a cantilever manner and accommodated therein, and a lid fixed to the package,
The tuning fork type piezoelectric vibrating piece is
A base portion fixed to the package side and a pair of vibrating arms extending in parallel from the base portion, and a notch portion between the base end portion of the vibrating arm and the base portion;
The width direction opposite ends of the base opposite to the vibrating arm are curved or chamfered ,
A piezoelectric device, wherein a conductive adhesive applied between a bottom surface of a base portion of the piezoelectric vibrating piece and an electrode portion of the package is applied on an inner side than the notch portion .   2. The piezoelectric device according to claim 1, wherein both end portions in the width direction of the base opposite to the vibrating arm are formed in a curved shape including a part of an ellipse or an ellipse. A piezoelectric device having a package in which a tuning fork-type piezoelectric vibrating piece is fixed in a cantilever manner and accommodated therein, and a lid fixed to the package,
The tuning fork type piezoelectric vibrating piece is
A base portion fixed to the package side and a pair of vibrating arms extending in parallel from the base portion, and a notch portion between the base end portion of the vibrating arm and the base portion;
At least both ends in the width direction on the opposite side of the vibrating arm of the base portion have an inclination inward toward the bottom surface ,
A piezoelectric device, wherein a conductive adhesive applied between a bottom surface of a base portion of the piezoelectric vibrating piece and an electrode portion of the package is applied on an inner side than the notch portion .

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