JP2004236008A - Piezo-electric oscillating member, piezo-electric device using the same, and cell phone unit and electric apparatus using piezo-electric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezo-electric oscillating member for restricting a CI value, by preventing a deterioration in oscillating characteristics caused by a difference of stiffness between right and left swinging arms. <P>SOLUTION: A tuning-fork type piezo-electric oscillating member 32 made up of a piezo-electric material with anisotropic characteristics by etching has a pair of oscillating arms 34, 35 extending in parallel from a base 51. The piezo-electric oscillating member 32 has a crotch 37 located between each oscillating arm of the base 51. The crotch has a notch 70 extending in a direction to which each oscillating arm extends, and located at a center of the base in a widthwise direction or from the center, located at a position nearer to one arm with higher rigidity out of each oscillating arm. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a piezoelectric vibrating reed, a piezoelectric device in which the piezoelectric vibrating reed is housed in a package, and a mobile phone and an electronic device using the piezoelectric device.
[0002]
[Prior art]
In a small information device such as an HDD (hard disk drive), a mobile computer, or an IC card, or a mobile communication device such as a mobile phone, a car phone, or a paging system, a piezoelectric vibrating piece is housed in a package. Piezoelectric devices such as vibrators and piezoelectric oscillators are widely used.
FIG. 8 is a schematic perspective view showing a configuration example of such a piezoelectric device (see Patent Document 1).
In the figure, a piezoelectric device 1 accommodates a piezoelectric vibrating reed 3 inside a package 2. In this case, the package 2 is made of an insulating material formed in a shallow box shape. After the piezoelectric vibrating reed 3 is housed and fixed inside, the package 2 is sealed by the lid 4.
[0003]
The piezoelectric vibrating reed 3 has a shape as shown in FIG. 8 by, for example, etching quartz. As shown in the drawing, the piezoelectric vibrating reed 3 includes a so-called tuning-fork type quartz vibrating reed having a base 5 and a pair of vibrating arms 6 and 7 extending in parallel from the base 5.
An excitation electrode (not shown) is formed on the piezoelectric vibrating reed 3. Electrodes 8 are provided in the package 2, and the base 5 of the piezoelectric vibrating reed 3 is joined to the electrodes 8 using conductive adhesives 8 a.
[0004]
Thus, by applying a drive voltage to the piezoelectric vibrating reed 3 from the outside via the electrode portions 8 of the package 2, the vibrating arms 6 and 7 move their tips toward and away from each other as shown by arrows. The bending vibration to be performed is performed at a predetermined vibration frequency. By extracting a vibration frequency based on such vibration, it is used for various signals such as a control clock signal.
[0005]
[Patent Document 1] Japanese Patent No. 3229005
[Problems to be solved by the invention]
FIG. 9 is a diagram illustrating a part of the piezoelectric vibrating reed 3 used in the above-described piezoelectric device 1.
Regarding the virtual center line C1 bisecting the width direction of the base 5 of the piezoelectric vibrating reed 3, it is preferable that the vibrating arms 6 and 7 have the same structural rigidity. That is, in order for the piezoelectric vibrating reed 3 to vibrate correctly, if the left and right structures in the figure do not have the same rigidity with respect to the center line C1, the bending vibrations of the vibrating arms 6 and 7 will vary, resulting in poor vibration performance. Has adverse effects.
[0007]
A possible cause of such rigidity imbalance is that the piezoelectric material for forming the piezoelectric vibrating reed 3 exhibits anisotropy due to etching.
That is, in order to form the tuning fork shape as shown in FIG. 8, the piezoelectric vibrating reed 3 needs to etch a piezoelectric material such as a quartz wafer. At the time of this etching, a fin-shaped deformed portion 9a is formed in the crotch portion 9 between the vibrating arms 6 and 7 shown in FIG. For example, as shown in FIG. 9, the deformed portion 9a has a large area on the right side of the center line C1. With such a structure, the right resonating arm 7 in the drawing becomes difficult to move, and A difference in rigidity between the left and right of the line C1, in other words, a difference in rigidity between the vibrating arm 6 and the vibrating arm 7 occurs.
[0008]
FIG. 10 is a vector analysis diagram of the above-described bending vibration of the piezoelectric vibrating reed 3. From the base 5 to the tips of the vibrating arms 6 and 7, approximately a, b, c, d, e, f, g, The displacement amount increases for each of the regions h and i.
In the case of the conventional piezoelectric vibrating piece 3, for example, the vibration frequency is 3.4944 · 10 4 Hz (Hertz) = 34.944 kHz (Kilohertz), and, for example, an arbitrary electric field energy (piezoelectric action) is applied. The displacement amount of the tip i of each of the vibrating arms 6 and 7 at the time is 6.57 · 10 −3 μm in the X direction, 4.02 · 10 −4 μm in the Y direction, and Z direction in the drawing. 3.49 · 10 minus 6 μm. This is because the displacement of the tip of each of the vibrating arms 6 and 7 is larger than in the normal state, and the displacement in the Z direction is particularly large.
[0009]
As a result, the oscillating arm 7 has higher rigidity than the oscillating arm 6, so that the vector vortex near the base or the base of the oscillating arm 7 collapses as shown in FIG. I have. It is understood that the vector vortex on the side of the vibrating arm 6 having low rigidity moves upward, and the form of the vector vortex is not balanced between left and right. Due to such vibration, there is a problem that the CI (crystal impedance) value of the piezoelectric vibrating reed 3 increases.
[0010]
The present invention relates to a so-called tuning-fork type piezoelectric vibrating reed, which is capable of preventing a deterioration in vibration characteristics due to a difference in rigidity between left and right vibrating arms and suppressing a CI value, and a piezoelectric vibrating reed such as described above. It is an object to provide a piezoelectric device used, and a mobile phone and an electronic device using the piezoelectric device.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a tuning-fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base, A crotch portion located between the vibrating arms of the base portion, and the crotch portion is closer to a higher rigidity of the respective vibrating arms from the center in the width direction of the base portion or from the center. This is achieved by a piezoelectric vibrating reed in which a cut is formed at a position along a direction in which each of the vibrating arms extends.
[0012]
According to the configuration of the first aspect, the notch is provided in the crotch portion located between the respective vibrating arms. Moreover, the cut is provided at the center of the base in the width direction or at a position closer to the side having higher rigidity than the center. By providing a cut in the crotch portion, a region divided by the cut becomes easy to move, so that the CI value at the time of bending vibration is reduced. In addition, since the notch is provided at a position closer to the higher rigidity side, the vibrating arm having higher rigidity can be more easily moved, thereby deteriorating vibration characteristics due to poor rigidity balance of each vibrating arm. Can be prevented.
Here, the cut includes a configuration in which a cut is formed in the base from the crotch side, a configuration in which a slit is formed in the base from the crotch side, and the like. Further, the present invention can be applied to not only the balance of the deformed shape formed at the crotch between the vibrating arms, but also the difference in rigidity of each vibrating arm based on the difference in material thickness.
Therefore, the present invention can provide an effect that it is possible to provide a piezoelectric vibrating reed that can prevent deterioration of vibration characteristics due to a difference in rigidity between the left and right vibrating arms and suppress the CI value.
[0013]
A second invention is characterized in that, in the configuration of the first invention, the crotch portion includes a deformed portion based on the anisotropy at a position corresponding to the higher rigidity side.
According to the configuration of the second aspect, the deformed portion formed by etching is formed on one side of the center of the crotch portion based on the anisotropy of the piezoelectric material. Alternatively, a main portion or a large area portion of the deformed portion is formed by one side of the center of the crotch portion. This makes it difficult for one side to move relative to the center due to the deformed portion. By forming the cut in such a region, the rigidity balance can be improved.
[0014]
According to a third aspect of the present invention, in the configuration according to any one of the first and second aspects, a center line C in the virtual width direction passing through the center and the vibrating arm on the higher rigidity side from the center line C are provided. When the distance from the inner surface is L, the cut is formed in a range of L / 2 from the center line C.
According to the third aspect of the invention, when the deformed portion formed by etching is formed closer to one side than the center of the crotch portion, the cut is formed in the range of L / 2 from the center line C. Thus, a part of the deformed portion can be left on one side, and the ease of movement and the rigidity can be balanced, so that the rigidity balance between the one side and the other can be appropriately adjusted.
[0015]
A fourth invention is characterized in that, in any one of the first to third inventions, the piezoelectric material is quartz.
According to the configuration of the fourth aspect, the single-crystal quartz exhibits the anisotropy by etching to form the deformed portion, and therefore, by providing the cut, the rigidity balance can be appropriately adjusted. .
[0016]
In a fifth aspect based on the configuration of the fourth aspect, the length direction of each vibrating arm is the X axis (electric axis) of the crystal, and the width direction of each vibrating arm is the Y axis (mechanical axis) of the crystal. Axis), the thickness direction of each of the vibrating arms is the Z axis (optical axis) of the quartz crystal, and the notch is provided near the plus X direction of the crotch portion.
According to the configuration of the fifth aspect, the deformed portion formed on the plus X direction side of the crotch portion by etching is larger than the deformed portion formed on the minus X direction side. By providing the notch near the direction, the vibrating arm that is hard to move can be more easily moved.
[0017]
According to a sixth aspect of the present invention, there is provided a tuning fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base. In the piezoelectric device housed in the, the piezoelectric vibrating reed, the crotch portion located between the respective vibrating arms of the base, the crotch, from the center or the center in the width direction of the base, This is achieved by a piezoelectric device in which a cut is formed at a position closer to a higher rigidity side of each of the vibrating arms along a direction in which each of the vibrating arms extends.
According to the configuration of the sixth aspect, the notch is provided in the crotch portion located between the respective vibrating arms of the piezoelectric vibrating reed used for the piezoelectric device. Since this notch acts in the same manner as in the first invention, the vibrating arms of the piezoelectric vibrating reed can be more easily moved, thereby preventing the vibration characteristics from being deteriorated due to poor rigidity balance of each vibrating arm. Can be.
[0018]
According to a seventh aspect of the present invention, there is provided a tuning fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base. A cellular phone device using a piezoelectric device housed therein, wherein the piezoelectric vibrating piece has a crotch portion located between the vibrating arms of the base, and the crotch portion has a width in the width direction of the base. A control clock signal is obtained by a piezoelectric device in which a notch is formed along the direction in which the respective vibrating arms extend at the center or at a position closer to the higher rigidity side of the respective vibrating arms from the center. This is achieved by the mobile telephone device.
According to an eighth aspect of the present invention, there is provided a tuning fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base. An electronic device using a piezoelectric device housed therein, wherein the piezoelectric vibrating reed is a crotch portion located between the respective vibrating arms of the base, and the crotch portion has a center in a width direction of the base. Alternatively, a clock signal for control may be obtained by a piezoelectric device having a notch formed at a position closer to a higher rigidity side of each of the vibrating arms from the center along the direction in which each of the vibrating arms extends. This is achieved by an electronic device.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 3 show an embodiment of the piezoelectric device of the present invention. FIG. 1 is a schematic plan view, FIG. 2 is a schematic sectional view taken along line AA of FIG. 1, and FIG. FIG. 4 is a sectional view taken along the line B.
In the drawing, the piezoelectric device 30 shows an example in which a piezoelectric vibrator is formed, and the piezoelectric device 30 accommodates a piezoelectric vibrating piece 32 in a package 36. The package 36 is formed, for example, by laminating a plurality of substrates formed by molding ceramic green sheets of aluminum oxide as an insulating material, and then sintering. Each of the plurality of substrates is formed with a predetermined hole inside thereof so that when stacked, a predetermined internal space S2 is formed inside when stacked. This embodiment is formed by laminating a first substrate 63 and a second substrate 64 in order to minimize the thickness of the package 36, and removing the material inside the second substrate 64. Thus form a space of the internal space S2.
This internal space S2 is a housing space for housing the piezoelectric vibrating reed.
[0020]
The first substrate 63 which is exposed to the internal space S2 and forms an inner bottom near the left end in the drawing of the internal space S2 of the package 36 has, for example, an electrode portion formed by nickel plating and gold plating on tungsten metallization. 31, 31 are provided.
The electrode portions 31 are connected to the outside and supply a drive voltage. A conductive adhesive 43 is applied on each of the electrode portions 31, and the extraction electrodes 33 provided on both ends in the width direction of the base 51 of the piezoelectric vibrating reed 32 on the conductive adhesive 43. , 33 are placed, and the conductive adhesives 43, 43 are cured. Each of the extraction electrodes 33 is connected to an excitation electrode of a piezoelectric vibrating piece 32 described later (not shown). In addition, as the conductive adhesives 43, 43, those obtained by adding conductive particles such as silver fine particles to a synthetic resin agent as an adhesive component exhibiting a bonding force can be used. Or polyimide-based conductive adhesive or the like can be used.
[0021]
The piezoelectric vibrating reed 32 is formed using a piezoelectric material having anisotropy by etching, and for example, single crystal quartz is used. Piezoelectric materials such as lithium tantalate and lithium niobate other than quartz can be used.
In FIG. 1, the piezoelectric vibrating piece 32 is formed, for example, by processing quartz as a piezoelectric material having anisotropy by etching into a tuning fork shape. In this case, the crystal is cut out of a single crystal of crystal such that the X axis shown in FIG. 1 is the electric axis, the Y axis is the mechanical axis, and the Z axis is the optical axis.
Further, the piezoelectric vibrating reed 32 includes a base 51 fixed to the package 36 side and a pair of vibrating arms 34 and 35 extending parallel to the right side in FIG. A so-called tuning-fork type piezoelectric vibrating reed, which has a shape like a tuning fork as a whole, is used.
[0022]
Further, the piezoelectric vibrating reed 32 preferably has a constricted portion or a notched portion 48, 48 provided near the base end of each of the vibrating arms 34, 35 of the base 51 so as to reduce the width of the base 51. Have. The piezoelectric vibrating reed 32 is provided with the notches 48, 48, so that leakage of vibrations from the vibrating arms 34, 35 to the base 51 side is suppressed.
[0023]
Each of the vibrating arms 34, 35 has a groove 44, 44 extending in the longitudinal direction, respectively. As shown in FIG. 3, the grooves 44 are formed on the front and back surfaces of the vibrating arms 34 and 35, respectively. At the end of the base 51 of the piezoelectric vibrating reed 32, as described with reference to FIG. 1, the lead electrodes 33, 33 for connecting to the electrodes 31, 31 of the package 36 are formed. The extraction electrodes 33 are provided on the front and back of the base 51 of the piezoelectric vibrating reed 32. These lead electrodes 33, 33 are connected to excitation electrodes provided in the grooves 44, 44 of the respective vibrating arms 34, 35.
[0024]
As shown in FIG. 3, the excitation electrode, which is a drive electrode of the piezoelectric vibrating reed 32, includes a first electrode 61 and a second electrode 62. The first electrode 61 and the second electrode 62 Are connected to the respective lead electrodes 33, 33 of FIG. The first electrode 61 and the second electrode 62 are separated from each other, and as shown in FIG. 3, in the region of each vibrating arm 34, 35, each groove 44, 44 The electrodes are formed on the side surfaces of the arms 34 and 35 so that the electrodes occupy positions facing each other.
Thereby, when a driving voltage is applied to the first electrode 61 and the second electrode 62, an electric field can be formed as shown by an arrow in FIG. 3, and each vibration is generated based on a frequency change of the driving voltage. Bending vibration is generated in the arms 34 and 35.
[0025]
A lid 39 is joined to the open upper end of the package 36 to seal it. After the lid 39 is preferably sealed and fixed to the package 36, as shown in FIG. 2, a laser beam LB is externally applied to the metal coating portion of the piezoelectric vibrating reed 32 or a part of the excitation electrode (not shown). In order to irradiate light and adjust the frequency by the mass reduction method, it is formed of a material that transmits light, in particular, a thin glass plate.
As a glass material suitable for the lid 39, for example, borosilicate glass is used as a thin glass manufactured by a down-draw method.
[0026]
FIG. 4 is an explanatory diagram showing, in an enlarged manner, a region at the base or root of each of the vibrating arms 34 and 35 of the piezoelectric vibrating reed 32 of FIG.
As shown, a substantially U-shaped crotch portion 37 is located in a region between the vibrating arms 34 and 35. Here, for the convenience of description, the center of the crotch portion 37, that is, the center in the width direction (X direction in FIG. 4) of the piezoelectric vibrating piece 32, passes along the length direction of the vibrating arm 34 and the vibrating arm 35. A virtual center line C is set. The cut 70 is provided at a position including the center line C and closer to the plus X direction than the center line C.
[0027]
The cut 70 is formed along the length direction of the vibrating arm 34 and the vibrating arm 35. The cut 70 is a cut or a slit, and needs to penetrate.
The cut 70 is provided in the piezoelectric vibrating reed 32 in consideration of the difference in rigidity between the vibrating arm 34 and the vibrating arm 35 that bend and vibrate. That is, in the case of a so-called tuning fork type piezoelectric vibrating reed, the vibrating arm 34 and the vibrating arm 35 of the piezoelectric vibrating reed 32 have the same shape and the same structure. However, for example, when the piezoelectric vibrating reed 32 is formed by etching a quartz wafer in the manufacturing process, the vibrating arm 34 and the vibrating arm 35 may not have exactly the same shape and structure. Increases rigidity.
In particular, when the above-mentioned crystal or the like having anisotropy due to etching is used as the material, as shown in FIG. 4, an irregular shape not matching the mask pattern or the like is formed at the crotch portion 37 or other places. In some cases, a deformed portion 73 is formed.
[0028]
For example, as shown in FIG. 4, the deformed portion 73 is formed as a fin-shaped portion having a thickness smaller than the material thickness of the base 51 and the vibrating arms 34 and 35. The deformed portion 73 has a relatively small area on the minus side in the X direction with respect to the center line C of the crotch portion 37, and has a relatively large area on the plus side in the X direction with respect to the center line C of the crotch portion 37. .
Due to the formation of such a deformed portion having a left-right unbalanced shape, the vibrating arm 35 has higher rigidity than the vibrating arm 34, and accordingly, the movement thereof is deteriorated, which adversely affects the performance of the bending vibration.
[0029]
Therefore, in FIG. 4, the cut 70 is formed at least along the center line C, preferably at a position closer to the plus side in the X direction than the center line C. Thereby, the vibrating arm 34 and the vibrating arm 35 of the piezoelectric vibrating reed 32 can be further separated left and right by the cuts 70 and the size of the deformed portion 72 can be balanced. And the vibrating arm 35 can have substantially the same rigidity.
[0030]
In this case, preferably, as shown in FIG. 4, the position where the cut 70 is formed is a distance between the center line C and the inner side surface 35 a of the vibrating arm 35 on the plus side in the X direction from the center line C. When L is set, it is formed in a range of 1 / 2L (a range of cuts 70-1 to 70-2 indicated by a dotted line).
Thereby, a part 72 of the deformed portion 73 can be left on the plus side in the X direction than the cut 70. Therefore, the other portion 71 of the deformed portion remaining on the minus side in the X direction than the cut 70 can be made substantially the same in area as the portion 72 of the deformed portion, and the height of ease of movement and rigidity can be improved. And the rigidity balance between the vibrating arm 34 and the vibrating arm 35 can be appropriately adjusted.
[0031]
FIG. 5 is a vector analysis diagram of the bending vibration of the piezoelectric vibrating reed 32 of the present embodiment. In each of the drawings, the distance from the base 51 to the tip of each of the vibrating arms 34 and 35 is approximately a, b, c, and c. The displacement amount increases for each of the regions d, e, f, g, h, and i. Although the detailed shape of the piezoelectric vibrating reed 32 is not shown in FIGS. 5 and 6 for convenience of illustration, it goes without saying that the shape and the structure are the same as those described in FIGS. 1 to 4.
[0032]
As illustrated, FIG. 5 is a vector analysis diagram of the bending vibration of the piezoelectric vibrating reed 32, omitting details including cuts and the like for the sake of simplicity. In the figure, the displacement amount gradually increases in each of the areas a, b, c, d, e, f, g, h, and i from the base 51 to the tip of each of the vibrating arms 34, 35. FIG. 6 is a vector analysis diagram of bending vibration of an ideal piezoelectric vibrating piece 32-1 when the vibrating arms 34-1 and 35-1 are formed with equal rigidity balance. Also in this figure, as the distance from the base 51-1 to the tip of each of the vibrating arms 34-1 and 35-1, each area of a, b, c, d, e, f, h, g, h, i , The displacement gradually increases.
[0033]
In the piezoelectric vibrating reed 32 in FIG. 5, for example, the vibration frequency is 3.4394 · 10 4 Hz (hertz) = 34.394 kHz (kilohertz), and, for example, the displacement amount of the tip of each of the vibrating arms 34 and 35. In the figure, the X direction is 2.41 · 10 −3 μm, the Y direction is 1.21 · 10 −4 μm, and the Z direction is 7.76 · 10 −7 μm in the Z direction.
In the ideal state of the piezoelectric vibrating piece 32-1 in FIG. 6, the vibration frequency is, for example, 3.378 · 10 × 4 Hz (hertz) = 33.781 kHz (kilohertz). The displacement of the tip of 35-1 is 2.51 · 10 −3 μm in the X direction, 1.26 · 10 −4 μm in the Y direction, and 8.40 · 10 in the Z direction. It is minus 7 μm.
[0034]
When FIG. 5 showing the piezoelectric vibrating reed 32 of this embodiment is compared with FIG. 6 in an ideal state and FIG. 10 prepared for a conventional piezoelectric vibrating reed, FIG. 5 is much closer to FIG. 6 than FIG. Is understood.
That is, in the piezoelectric vibrating reed 32 of FIG. 5 in which the notch is formed, the displacement amount in the Z direction is smaller by about one digit as compared with the conventional example of FIG. 10, which is very close to the ideal state of FIG. As a result, as shown in FIG. 5, the vector vortices of the left and right vibrating arms 34 and 35 are almost symmetrical, and the rigidity balance is greatly improved.
[0035]
As described above, according to the piezoelectric vibrating reed 32 of the present embodiment, by providing the cut 70 in the crotch portion 37 located between the vibrating arms 34 and 35, the vibrating arms 34 and 35 separated by the cut are formed. Since the base portion becomes easy to move, the CI value at the time of bending vibration is reduced. In particular, since the notch 70 is provided at a position closer to the side having higher rigidity, the vibrating arm 35 having higher rigidity can be more easily moved. Deterioration of vibration characteristics can be prevented.
[0036]
FIG. 7 is a diagram illustrating a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the piezoelectric device according to the 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 is provided. CPU (Central Processing Unit) 301.
In addition to modulation and demodulation of transmission / reception signals, a CPU 301 includes an LCD as an image display, an information input / output unit 302 including operation keys for inputting information, and a memory 303 as an information storage unit such as a RAM and a ROM. Control is performed. Therefore, the piezoelectric device 30 is attached to the CPU 301, and its output frequency is used as a clock signal suitable for the control content by a predetermined frequency dividing circuit (not shown) or the like built in the CPU 301. ing. The piezoelectric device 30 attached to the CPU 301 is not limited to the piezoelectric device 30 alone, but may be an oscillator combining the piezoelectric device 30 or the like with a predetermined frequency dividing circuit or the like.
[0037]
The CPU 301 is further connected to a temperature-compensated crystal oscillator (TCXO) 305, and the temperature-compensated crystal oscillator 305 is connected to a transmitting unit 307 and a receiving unit 306. Thus, even if the basic clock from the CPU 301 fluctuates when the environmental temperature changes, it is corrected by the temperature-compensated crystal oscillator 305 and provided to the transmitting unit 307 and the receiving unit 306.
[0038]
As described above, by using the piezoelectric vibrating reed 32 according to the above-described embodiment and the piezoelectric device 30 using the same in an electronic device such as the digital mobile phone device 300 including the control unit, Since the CI value can be suppressed by improving the rigidity balance between 34 and 35, appropriate vibration can be realized, and thus an accurate clock signal can be generated.
[0039]
The invention is not limited to the embodiments described above. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with another configuration not shown.
The present invention is applicable to all piezoelectric devices regardless of the names of the piezoelectric vibrator and the piezoelectric oscillator as long as the piezoelectric vibrating reed is housed in a package or a metal cylindrical case or the like. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an embodiment of a piezoelectric device of the present invention.
FIG. 2 is a schematic sectional view taken along line AA of FIG. 1;
FIG. 3 is a sectional view taken along line BB of FIG. 1;
FIG. 4 is an explanatory diagram showing, in an enlarged manner, a region at the base or base of each vibrating arm of the piezoelectric vibrating reed of FIG. 1;
FIG. 5 is a vector analysis diagram of bending vibration of the piezoelectric vibrating reed of FIG. 1;
FIG. 6 is a vector analysis diagram of flexural vibration of the piezoelectric vibrating reed in an ideal state with respect to the rigidity balance of the vibrating arm.
FIG. 7 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 an embodiment of the present invention.
FIG. 8 is a schematic perspective view showing an example of a conventional piezoelectric device.
9 is a partially enlarged view of a piezoelectric vibrating reed used in the piezoelectric device of FIG.
FIG. 10 is a vector analysis diagram of bending vibration of a piezoelectric vibrating reed used in the piezoelectric device of FIG. 8;
[Explanation of symbols]
Reference numeral 30 denotes a piezoelectric device, 32 denotes a piezoelectric vibrating piece, 34, 35 denotes a vibrating arm, 36 denotes a package, 37 denotes a crotch part, 70 denotes a cut, and 73 denotes a deformed part.

Claims (8)

A tuning fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base,
A crotch portion located between the vibrating arms of the base,
In the crotch portion, a notch is formed along a direction in which each of the vibrating arms extends at a position closer to a higher rigidity of the respective vibrating arms from the center in the width direction of the base portion or from the center. A piezoelectric vibrating reed, characterized in that: The piezoelectric vibrating reed according to claim 1, wherein the crotch portion includes a deformed portion based on the anisotropy at a position corresponding to the higher rigidity side. When a distance between an imaginary width direction center line C passing through the center and the inner surface of the vibrating arm on the higher rigidity side from the center line C is L, the notch is shifted from the center line C. The piezoelectric vibrating reed according to claim 1, wherein the piezoelectric vibrating reed is formed in a range of L / 2. 4. The piezoelectric vibrating reed according to claim 1, wherein the piezoelectric material is quartz. The length direction of each vibrating arm is the X axis (electric axis) of the crystal, the width direction of each vibrating arm is the Y axis (mechanical axis) of the crystal, and the thickness direction of each vibrating arm is the The piezoelectric vibrating reed according to claim 4, wherein the piezoelectric vibrating reed is a Z-axis (optical axis) of the quartz crystal, and the cut is provided near the crotch portion in the positive X direction. A piezoelectric device formed of a piezoelectric material having anisotropy by etching and containing a tuning-fork type piezoelectric vibrating reed having a pair of vibrating arms extending in parallel from a base in a case or a package,
The piezoelectric vibrating reed,
A crotch portion located between the vibrating arms of the base,
In the crotch portion, a notch is formed along a direction in which each of the vibrating arms extends at a position closer to a higher rigidity of the respective vibrating arms from the center in the width direction of the base portion or from the center. A piezoelectric device, comprising: A mobile phone device using a piezoelectric device in which a tuning-fork type piezoelectric vibrating reed formed of a piezoelectric material having anisotropy by etching and having a pair of vibrating arms extending in parallel from a base is accommodated in a case or a package. So,
The piezoelectric vibrating reed,
A crotch portion located between the vibrating arms of the base,
In the crotch portion, a notch is formed along a direction in which each of the vibrating arms extends at a position closer to a higher rigidity of the respective vibrating arms from the center in the width direction of the base portion or from the center. A cellular phone device wherein a clock signal for control is obtained by the piezoelectric device. An electronic device using a piezoelectric device formed of a piezoelectric material having anisotropy by etching and having a tuning fork type piezoelectric vibrating reed provided with a pair of vibrating arms extending in parallel from a base in a case or a package. hand,
The piezoelectric vibrating reed,
A crotch portion located between the vibrating arms of the base,
In the crotch portion, a notch is formed along a direction in which each of the vibrating arms extends at a position closer to a higher rigidity of the respective vibrating arms from the center in the width direction of the base portion or from the center. An electronic device, wherein a clock signal for control is obtained by the piezoelectric device.

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