JP2004120249A - Piezoelectric vibration chip and piezoelectric device utilizing piezoelectric vibration chip, and mobile phone utilizing piezoelectric device, and electronic apparatus utilizing piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibration chip whose frequency can be adjusted by adopting a mass reduction method without substantially reducing the area of a region related to vibration of the piezoelectric vibration chip and giving adverse effect on the vibration characteristic and to provide a piezoelectric device utilizing the piezoelectric vibration chip. <P>SOLUTION: The piezoelectric vibration chip is provided with: a pair of vibration arms 34, 35 made of a piezoelectric material and extended in parallel from a base; grooves 56, 57 provided to the vibration arms respectively and extended in the length direction; and a frequency adjustment section wherein island or peninsular regions are formed in the grooves and metal coating parts 61, 62 for adjustment purpose are provided on the surface of the regions. <P>COPYRIGHT: (C)2004,JPO

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. 10 is a schematic perspective view showing a configuration example of such a piezoelectric device.
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. Note that the lid 4 of the piezoelectric device 1 in FIG. 10 is transparent.
[0003]
The shape of the piezoelectric vibrating reed 3 is formed by, for example, etching quartz. In this case, the piezoelectric vibrating reed 3 is composed of a so-called tuning-fork type crystal piece including a base 5 and a pair of vibrating arms 6 and 7 extending in parallel to the left from the base 5 in the drawing. Exciting electrodes 8, 8 are formed on the surfaces of the vibrating arms 6, 7, and when a driving voltage is applied to the exciting electrodes 8, 8 from the outside, the vibrating arms 6, 7 are moved to the tip side. Vibrates so that they approach and separate from each other. By extracting a vibration frequency based on such vibration, it is used for various signals such as a control clock signal.
[0004]
[Problems to be solved by the invention]
By the way, in the piezoelectric device 1 having such a structure, in each of the vibrating arms 6 and 7, the excitation electrodes 8 and 8 are formed halfway in the longitudinal direction, and near the tip of each of the vibrating arms 6 and 7, Metal coating portions 9, 9 different from the electrodes are provided. In the manufacturing process, after the piezoelectric vibrating reed 3 is housed and fixed in the package 2, the final frequency adjustment of the piezoelectric vibrating reed 3 after sealing with the transparent lid 4 is performed in the manufacturing process. Used to do.
[0005]
That is, as shown in FIG. 10, by irradiating the metal cover 9 with a light beam L1 such as a laser beam that passes through the lid 4 and partially evaporates the metal cover 9, The frequency adjustment of the mass reduction method is performed.
However, since the metal coating portions 9 are provided at the tips of the respective vibrating arms 6 and 7, the locations where the excitation electrodes 8 and 8 are provided are limited to a region halfway through the respective vibrating arms 6 and 7. I will.
When the region where the excitation electrodes 8 and 8 of each of the vibrating arms 6 and 7 are provided is limited halfway as shown in FIG. 10, the area of the excitation electrodes involved in the vibration of each of the vibrating arms 6 and 7 is reduced. There is a disadvantage that the resistance value of the piezoelectric vibrating piece 3 increases with the decrease.
[0006]
In particular, in order to reduce the size of the piezoelectric vibrating reed 3 and the piezoelectric device 1, it is necessary to further reduce the overall size of the piezoelectric vibrating reed 3. The absolute area of the part involved is increasingly reduced.
Therefore, a configuration as shown in FIG. 11 is also conceivable.
In the piezoelectric vibrating reed 13 shown in FIG. 11, the exclusive metal coating 9 for frequency adjustment is eliminated, and the excitation electrodes 8, 8 of each of the vibrating arms 6, 7 are extended to near the distal end. By irradiating the laser beams L1 to the tips 8a, 8a, the frequency is to be adjusted.
However, according to such a method, a hole is formed at the tip of the excitation electrodes 8, 8, and the electric field to be formed during the vibration in each of the vibrating arms 6, 7 is disturbed, which adversely affects the vibration performance. give.
[0007]
The present invention provides a piezoelectric vibrating reed in which the frequency can be adjusted by a mass reduction method without substantially reducing the area of a region involved in the vibration of the piezoelectric vibrating reed and without adversely affecting the vibration characteristics. It is another object of the present invention to provide a piezoelectric device using the piezoelectric vibrating reed, and a mobile phone and an electronic device using the piezoelectric device.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, the above object is provided with a pair of vibrating arms formed of a piezoelectric material and extending in parallel from a base, provided on each of the vibrating arms, and along a length direction of each of the vibrating arms. By a piezoelectric vibrating reed, a groove extending to the vicinity of the tip, and a predetermined area raised above the bottom of the groove in the groove, and a frequency adjusting section provided with a metal coating for adjustment on the surface of the area, Achieved.
[0009]
According to the configuration of the first invention, the pair of vibrating arms extending in parallel from the base are formed with grooves extending to the vicinity of the distal end along the length direction of each vibrating arm. By providing the excitation electrode inside this groove, it can be used as a region involved in vibration up to the longitudinal end of each vibrating arm.
Then, a predetermined region is formed in the groove so as to be higher than the bottom of the groove, and a metal coating portion is provided in that region. By irradiating the metal coating with laser light or the like, the frequency can be adjusted without affecting the excitation electrode.
For this reason, according to the present invention, the frequency can be adjusted by the mass reduction method without substantially reducing the area of the region involved in the vibration of the piezoelectric vibrating reed and without adversely affecting the vibration characteristics. The effect of being able to provide the piezoelectric vibrating reed of the present invention is provided.
[0010]
According to a second aspect, in the configuration of the first aspect, the predetermined region is a peninsula provided near a longitudinal end of each of the vibrating arms.
According to the configuration of the second invention, since the peninsula is provided near the tip of each vibrating arm, the mass near the tip of each vibrating arm can be adjusted. Thereby, the adjustment width of the vibration frequency of the piezoelectric vibrating reed can be increased.
[0011]
According to a third aspect of the present invention, in the configuration of the first aspect, the predetermined region is an island portion provided near a center in a length direction of each of the vibrating arms.
According to the configuration of the third aspect, the predetermined region is an island (Island-island) provided near the center in the length direction of each of the vibrating arms. Therefore, it is possible to reduce the mass in the vicinity of the middle in the length direction of each vibrating arm, and it is possible to finely adjust the vibration frequency of the piezoelectric vibrating reed which needs to be adjusted in a minute width. Thereby, it is possible to precisely adjust the vibration frequency.
[0012]
A fourth invention is characterized in that, in any one of the first to third inventions, the base has a notch in a region close to a base end of the vibrating arm.
According to the configuration of the fourth invention, in the tuning-fork type vibrating reed, by forming the notch in the base thereof, it is possible to effectively prevent the vibration from the vibrating arm from leaking into the base, and to reduce the crystal impedance value. Can be suppressed.
[0013]
According to a fifth aspect of the present invention, there is provided a piezoelectric device in which a piezoelectric vibrating reed is housed in a package, wherein at least a part of the package is configured to transmit light. A vibrating reed is formed of a piezoelectric material, and a pair of vibrating arms extending in parallel from the base, a groove provided in each of the vibrating arms, a groove extending in the length direction thereof, and an island-shaped or peninsula-shaped This is achieved by a piezoelectric device including: a frequency adjusting unit that forms a region and has a metal coating portion for adjustment provided on the surface of the region.
According to the configuration of the fifth aspect, the pair of vibrating arms extending in parallel from the base are formed with the grooves extending to the vicinity of the tip along the length direction of each vibrating arm. By providing the excitation electrode inside this groove, it can be used as a region involved in vibration up to the longitudinal end of each vibrating arm.
Then, an island-shaped or peninsula-shaped region is formed in the groove to provide a metal coating portion, and a laser is applied to the metal coating portion of the piezoelectric vibrating reed via a transparent portion of the package, for example, a glass lid on the package. By irradiating light or the like, the frequency can be adjusted without affecting the excitation electrode.
[0014]
According to a sixth aspect of the present invention, there is provided a mobile phone device using a piezoelectric device in which a piezoelectric vibrating piece is housed in a package, wherein the piezoelectric vibration is formed in a piezoelectric material, and A pair of vibrating arms extending parallel to each other, a groove provided in each of the vibrating arms, a groove extending in the length direction thereof, and an island-shaped or peninsula-shaped region is formed in the groove, and a surface for adjustment is formed on the surface of the region. The present invention is achieved by a cellular phone device that obtains a control clock signal by a piezoelectric device including a frequency adjustment unit provided with a metal coating unit.
[0015]
Still further, according to a seventh aspect of the present invention, there is provided an electronic apparatus using a piezoelectric device in which a piezoelectric vibrating piece is housed in a package, wherein the piezoelectric vibrating piece is formed of a piezoelectric material. A pair of vibrating arms extending in parallel from the base, a groove provided on each of the vibrating arms and extending in the length direction thereof, and an island-shaped or peninsula-shaped region formed in the groove; The present invention is achieved by an electronic apparatus that obtains a control clock signal by using a piezoelectric device including a frequency adjustment unit provided with a metal coating unit.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show a first embodiment of the piezoelectric device of the present invention. FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic sectional view taken along line AA of FIG.
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 internal space S2 is a housing space for housing the piezoelectric vibrating reed.
That is, as shown in FIG. 2, in this embodiment, the package 36 is formed by, for example, stacking a first laminated substrate 61, a second laminated substrate 64, and a third laminated substrate 68 from below. ing.
[0017]
In the drawing of the inner space S2 of the package 36 near the left end in the drawing, the second laminated substrate 64 exposed to the inner space S2 and constituting the inner bottom portion has, for example, electrodes formed by nickel plating and gold plating on tungsten metallization. Parts 31, 31 are provided.
The electrode portions 31 are connected to the outside and supply a drive voltage. A conductive adhesive 43, 43 is applied on each of the electrode portions 31, 31, and a base 51 of the piezoelectric vibrating reed 32 is placed on the conductive adhesive 43, 43, and the conductive adhesive 43 , 43 are cured. 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.
[0018]
The piezoelectric vibrating reed 32 is made of, for example, quartz, and a piezoelectric material other than quartz, such as lithium tantalate or lithium niobate, can be used. In the case of the present embodiment, the piezoelectric vibrating reed 32 is formed in a small size, and has a shape shown in particular in order to obtain necessary performance.
In other words, the piezoelectric vibrating reed 32 includes a base 51 fixed to the package 36 side as described later, and a pair of vibrators extending in parallel to the right side in the figure and bifurcated with the base 51 as a base end. A so-called tuning-fork type piezoelectric vibrating reed having arms 34 and 35 and having a whole shape like a tuning fork is used.
The detailed configuration of the piezoelectric vibrating reed 32 will be described later.
[0019]
A through hole 37 that is open to the outside is provided near the center of the bottom surface of the package 36 by forming through holes 37a and 37b that are continuous with the two laminated substrates that constitute the package 36. Out of the two through-holes constituting the through-hole 37, the outer through-hole 37a, which is the second hole, has a larger inner diameter than the first hole 37b opened inside the package. I have. Thereby, the through-hole 37 is a stepped opening including the downward stepped portion 62 in FIG. 2. A metal coating (not shown) is provided on the surface of the step 62.
[0020]
Here, as the metal sealing material 38 filled in the through hole 37, for example, a sealing material containing no lead is preferably selected. For example, silver brazing, Au / Sn alloy, Au / Ge alloy And so on. Correspondingly, it is preferable to form nickel plating and gold plating on the tungsten metallization on the metal coating on the surface of the step 62.
[0021]
Further, in this embodiment, a recess 42 corresponding to the thickness of the laminated substrate is formed in the lowermost substrate 61 of the laminated substrate constituting the package 36 by forming a hole near the right end in FIG. ing. The recess 42 is located below the free end of the piezoelectric vibrating reed 32. Thus, in the present embodiment, even when the free end of the piezoelectric vibrating piece 32 is displaced in the direction of arrow D and shakes when an external shock is applied to the package 36, the piezoelectric vibrating piece 32 abuts against the inner bottom surface of the package 36. This is effectively prevented from being done.
[0022]
A lid 39 is joined to the open upper end of the package 36 to seal it. After the lid 39 is sealed and fixed to the package 36, as shown in FIG. 2, a laser beam L2 is externally applied to a metal coating portion of the piezoelectric vibrating reed 32, as shown in FIG. To do this, it is made of a light-transmitting material, 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.
[0023]
Next, the piezoelectric vibrating reed 32 (first embodiment of the piezoelectric vibrating reed) housed in the package 36 of the piezoelectric device 30 will be described in detail with reference to FIGS.
3 is a schematic perspective view showing the configuration of the piezoelectric vibrating reed 32, FIG. 4 (a) is an end view taken along the line BB of FIG. 3 (a view showing only a cut surface), and FIG. It is a CC sectional view end view.
In FIG. 3, the piezoelectric vibrating reed 32 has a pair of vibrating arms 34 and 35 extending in parallel from the base 51 as described above. The vibrating arms 34 and 35 have grooves 56 and 57 extending in the length direction, respectively. As shown in FIGS. 4A and 4B, the grooves 56 and 57 are formed on the front and back surfaces of the vibrating arms 34 and 35, respectively.
[0024]
Further, in FIG. 3, extraction electrodes 52 and 53 are formed near both ends in the width direction of the end (the right end in FIG. 3) of the base 51 of the piezoelectric vibrating reed 32. The extraction electrodes 52 and 53 are similarly formed on the back surface (not shown) of the base 51 of the piezoelectric vibrating piece 32.
These lead electrodes 52 and 53 are portions connected to the electrode portions 31 and 31 on the package 36 side described with reference to FIGS. 1 and 2 by the conductive adhesives 43 and 43, respectively. As shown, the extraction electrodes 52 and 53 are connected to excitation electrodes 54 and 55 provided in grooves 56 and 57 of the vibrating arms 34 and 35, respectively. As shown in FIG. 4, the excitation electrodes 54 and 55 are also formed on both side surfaces of each of the vibrating arms 34 and 35, and one of the vibrating arms, for example, the vibrating arm 34 has a groove 57. The excitation electrode 54 in the inside and the excitation electrode 55 on the side surface thereof have different polarities from each other.
[0025]
Further, in the grooves 56, 57, preferably near the tips of the vibrating arms 34, 35, there is provided a frequency adjusting section in which the piezoelectric material constituting the piezoelectric vibrating reed 32 is provided partially higher than the bottom of the grooves. Have been. The frequency adjustment unit is provided by leaving a groove for etching only in the region in a step of etching, for example, quartz as a piezoelectric material to form the outer shape of the piezoelectric vibrating reed 32 in a manufacturing process. In this embodiment, the frequency adjusting portion is connected to each of the vibrating arms 34 and 35 such that the leading end portions 34a and 35a of the vibrating arms 34 and 35 are continuous with the portions where the grooves are not formed as shown in the drawing. Peninsular portions 58 and 59 extend in the direction in which the groove extends within 56 and 57.
The surfaces of these peninsula portions 58, 59 are coated with metal to form metal coating portions 61, 62. The metal constituting these metal coating portions 61, 62 may be the same as the excitation electrodes 54, 55, but may be coated with a different metal. When the excitation electrodes 54 and 55 are the same, gold (Au) is deposited by vapor deposition or sputtering with chromium (Cr) as a base. In this embodiment, the metal coating portions 61 and 62 are not connected to the excitation electrodes 54 and 55, but may be connected.
[0026]
The piezoelectric vibrating reed 32 of the present embodiment is configured as described above, and the driving voltage applied from the package 36 side is transmitted to the excitation electrodes 54 and 55 via the lead electrodes 52 and 53.
Here, as shown in FIGS. 4A and 4B, the inner surfaces of the grooves 56 and 57 and the excitation electrodes on the side surfaces of the vibrating arms 34 and 35 have different polarities. An electric field is generated, and based on the electric field, the vibrating arms 34, 35 vibrate so that their foremost portions 34a, 35a approach and separate from each other.
[0027]
In this case, since the grooves 56 and 57 of each of the vibrating arms 34 and 35 are formed up to the vicinity of the tip of each of the vibrating arms 34 and 35, almost the entire length of each of the vibrating arms 34 and 35 becomes a region involved in vibration, and Even when the resonator element 32 is formed small, the absolute area of the excitation electrodes 54 and 55 involved in vibration does not decrease.
[0028]
Further, as described with reference to FIG. 2, the frequency of the peninsula portions 58 and 59 is adjusted by irradiating the package 36 with the laser beam L2 or the like after the lid 39 is sealed. Specifically, by irradiating the metal coating portion 61 and / or 62 with the laser beam L2 or the like and partially evaporating the same, it is possible to reduce the mass of the portion and adjust the frequency so that the vibration frequency becomes higher. it can.
[0029]
Here, since the peninsula portions 58 and 59 are provided near the tips of the vibrating arms 34 and 35, the mass near the tips of the vibrating arms 34 and 35 can be adjusted. Thereby, the adjustment range of the vibration frequency can be widened.
[0030]
The peninsula portions 58 and 59 are formed to provide the metal coating portions 61 and 62 for frequency adjustment as described above, but the peninsula portions 58 and 59 without the metal coating portions 61 and 62 are shown in FIG. As shown in a), the vibrating arms 34 and 35 are also formed on the back side. Thus, the weight balance between the front side and the back side of each of the vibrating arms 34 and 35 is matched, so that the vibration performance is improved as compared with the case where only one of them is provided.
[0031]
FIG. 5 shows a modification of the first embodiment of the piezoelectric vibrating reed. In the piezoelectric vibrating reed 70 of this modified example, the portions denoted by the same reference numerals as those in FIGS. 3 and 4 have the same configuration, and thus the overlapping description will be omitted, and the differences will be mainly described.
In FIG. 5, the piezoelectric vibrating reed 70 differs from the piezoelectric vibrating reed 32 in the configuration of the metal coating portions 71 and 72, and the other configurations are the same. However, in this case, the metal coating portions 71 and 72 are not connected to the excitation electrodes 54 and 55.
[0032]
The metal covering portions 71 and 72 of the piezoelectric vibrating piece 70 are integrally connected to the excitation electrodes 54 and 55 routed to the foremost portions 34a and 35a of the vibrating arms 34 and 35.
For this reason, the metal covering portions 71 and 72 of the piezoelectric vibrating piece 70 are formed simultaneously with the formation of the excitation electrodes 54 and 55 on the piezoelectric vibrating piece 70 in the manufacturing process. It is not necessary to provide a step of forming only the steps, and the steps can be simplified accordingly. Other functions and effects are the same as those of the piezoelectric vibrating piece 32.
[0033]
Next, the piezoelectric vibrating piece 80 (the second embodiment of the piezoelectric vibrating piece) housed in the package 36 of the piezoelectric device 30 will be described in detail with reference to FIGS.
FIG. 6 is a schematic perspective view showing the configuration of the piezoelectric vibrating reed 80, FIG. 7A is a cross-sectional end view taken along line DD of FIG. 6, and FIG. 7B is a cross-sectional end view taken along line EE of FIG. is there.
In these figures, the portions denoted by the same reference numerals as those in FIGS. 3 and 4 have the same configuration, and thus the duplicated description will be omitted, and the description will focus on the differences.
6 and 7, in the piezoelectric vibrating piece 80, the configuration of the frequency adjustment unit is different from that of the piezoelectric vibrating piece 32, and the other configuration is the same.
[0034]
In this piezoelectric vibrating reed 80, the frequency adjusting portion is not peninsula-shaped, but in the vicinity of the center in the longitudinal direction of each of the grooves 56, 57, in an isolated convex shape, and along the extending direction of each of the grooves 56, 57. Island portions 88 and 89 formed in a long shape.
Then, metal coating portions 81 and 82 are formed on the surfaces (upper surfaces in the drawings) of the island portions 88 and 89, respectively. The metal covering portions 81 and 82 can be formed of the same metal as the metal covering portions 61 and 62 of the first embodiment of the piezoelectric vibrating reed.
[0035]
The present embodiment is configured as described above, and can exhibit the same functions and effects as those of the first embodiment, and the island portions 88 and 89 are formed near the middle of the respective vibrating arms 34 and 35 in the longitudinal direction. Therefore, if the frequency is adjusted by using the metal coating portions 81 and 82, the mass of the vibrating arms 34 and 35 near the center in the length direction can be reduced. As a result, the adjustment width of the vibration frequency of the piezoelectric vibrating piece 80 can be finely adjusted with a relatively small width, so that the vibration frequency can be precisely adjusted.
As a result, the piezoelectric vibrating reed 80 of the piezoelectric device that requires the adjustment of the vibration frequency with extremely high accuracy uses a conventional laser device to apply the same amount of metal coating as the tip of the vibrating arm of the above-described embodiment. Even if it evaporates, the frequency change amount which can be adjusted becomes smaller. In other words, for fine adjustment, the laser output is bothersome adjusted to be low, and as a result, there is no possibility that the evaporation amount of the metal film becomes unstable, so that extremely high-precision frequency adjustment can be easily performed.
As described above, the frequency adjustment unit can be set at a predetermined position in the length direction of each of the vibrating arms 34 and 35 according to the necessary adjustment width by the frequency adjustment. The frequency adjustment unit may be provided not only near the front end or the middle in the length direction of each vibrating arm, but also on both or more places.
[0036]
FIG. 8 is a schematic perspective view of a piezoelectric vibrating piece 90 (third embodiment of the piezoelectric vibrating piece) housed in the package 36 of the piezoelectric device 30.
In FIG. 8, the portions denoted by the same reference numerals as those in FIGS. 3 and 4 have the same configuration, and thus the duplicate description will be omitted, and the description will focus on the differences.
In FIG. 8, the structure around the base 51 of the piezoelectric vibrating reed 90 is different from that of the piezoelectric vibrating reed 32 as compared with the piezoelectric vibrating reed 32, and the other configuration is the same.
[0037]
That is, in the base 51 of the piezoelectric vibrating piece 90, at a position close to the base end side of the pair of vibrating arms 34 and 35, a notch or constriction 91, which is provided with a reduced width in the width direction of the base 51, 91 may be provided.
Thereby, leakage of the vibration of the piezoelectric vibrating piece 90 into the base 51 can be prevented, and the CI (crystal impedance) value can be reduced.
Other functions and effects are the same as those of the first embodiment.
[0038]
FIG. 9 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 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 is provided. CPU (Central
(Processing Unit) 301.
The CPU 301 controls the input / output unit 302 including an LCD as an image display unit and operation keys for inputting information, and the information storage unit 303 including a RAM and a ROM, in addition to modulation and demodulation of transmission / reception signals. Is supposed to do it. For this reason, the piezoelectric device 30 or the piezoelectric device 90 or the piezoelectric device 100 is attached to the CPU 301, and the output frequency thereof is adapted to the control content by a predetermined frequency dividing circuit (not shown) built in the CPU 301. It is used as a clock signal. 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.
[0039]
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.
[0040]
As described above, the piezoelectric vibrating reeds 32, 70, 80, and 90 according to the above-described embodiment and the piezoelectric device 30 using the same are used in an electronic apparatus such as the digital cellular phone device 300 including the control unit. This allows accurate frequency adjustment even in a small-sized configuration, so that an accurate clock signal can be generated.
[0041]
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.
Further, the present invention can be applied to all piezoelectric devices irrespective of the names of the piezoelectric vibrator, the piezoelectric oscillator, and the like as long as the piezoelectric vibrating reed is housed in the package.
In the above-described embodiment, a box-shaped package using a piezoelectric material is used for the package. However, the present invention is not limited to such a form, and at least a part of the package is provided with a portion through which light can pass. If so, the present invention can be applied to any package and case.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a first 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 schematic perspective view showing a first embodiment of a piezoelectric vibrating reed used in the piezoelectric device of FIG. 1;
4A and 4B are cross-sectional end views of FIG. 3, wherein FIG. 4A is a cross-sectional view taken along line BB of FIG. 3, and FIG. 4B is a cross-sectional end view taken along line CC of FIG.
FIG. 5 is a schematic perspective view showing a modification of the piezoelectric vibrating reed of FIG. 3;
FIG. 6 is a schematic perspective view showing a second embodiment of a piezoelectric vibrating reed used in the piezoelectric device of FIG. 1;
7 is a sectional end view of FIG. 6, (a) is a sectional view taken along line DD of FIG. 6, and (b) is a sectional end view of line EE of FIG.
FIG. 8 is a schematic perspective view showing a third embodiment of a piezoelectric vibrating reed used in the piezoelectric device of FIG. 1;
FIG. 9 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. 10 is a schematic perspective view showing an example of a conventional piezoelectric device.
11 is a schematic perspective view of a piezoelectric vibrating reed used in the piezoelectric device of FIG.
[Explanation of symbols]
30, a piezoelectric device, 32, 70, 80, 90, a piezoelectric vibrating piece, 58, 59, a peninsula, 61, 62, 71, 72, 81, 82, a metal coating, 88, 89 ... Island part.

Claims (7)

A pair of vibrating arms formed of a piezoelectric material and extending in parallel from the base,
A groove provided in each of the vibrating arms, extending along the length direction of each vibrating arm to near the tip;
A piezoelectric vibrating reed comprising: a frequency adjusting section in which a predetermined area higher than the bottom of the groove is formed in the groove, and a metal coating section for adjustment is provided on the surface of the area. The piezoelectric vibrating reed according to claim 1, wherein the predetermined area is a peninsula provided near a longitudinal end of each of the vibrating arms. The piezoelectric vibrating reed according to claim 1, wherein the predetermined area is an island portion provided near a center in a length direction of each of the vibrating arms. The piezoelectric vibrating reed according to any one of claims 1 to 3, wherein the base has a notch in a region close to a base end of the vibrating arm. A piezoelectric device containing a piezoelectric vibrating reed in a package,
At least a part of the package is configured to transmit light,
The piezoelectric vibrating reed,
A pair of vibrating arms formed of a piezoelectric material and extending in parallel from the base,
A groove provided in each of the vibrating arms and extending in the length direction thereof;
A piezoelectric device comprising: an island-shaped or peninsular-shaped region formed in the groove; and a frequency adjustment unit provided with a metal coating portion for adjustment on the surface of the region. A mobile phone device using a piezoelectric device containing a piezoelectric vibrating reed in a package,
The piezoelectric vibrating reed,
A pair of vibrating arms formed of a piezoelectric material and extending in parallel from the base,
A groove provided in each of the vibrating arms and extending in the length direction thereof;
A clock signal for control is obtained by a piezoelectric device including an island-shaped or peninsula-shaped region formed in the groove, and a frequency adjustment unit provided with a metal coating for adjustment on the surface of the region. A mobile phone device characterized by the above-mentioned. An electronic device using a piezoelectric device containing a piezoelectric vibrating piece in a package,
The piezoelectric vibrating reed,
A pair of vibrating arms formed on the piezoelectric material and extending in parallel from the base,
A groove provided in each of the vibrating arms and extending in the length direction thereof;
A clock signal for control is obtained by a piezoelectric device including an island-shaped or peninsula-shaped region formed in the groove, and a frequency adjustment unit provided with a metal coating for adjustment on the surface of the region. Electronic equipment characterized by the following.

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