JP2007184752A - Piezoelectric vibrator and radio controlled watch equipped with the same, oscillator, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator which can not only have piezoelectric vibrating pieces easily mounted with high precision, but also be improved in durability, a radio controlled watch equipped with the same, an oscillator, and electronic equipment. <P>SOLUTION: The piezoelectric vibrator is equipped with a piezoelectric vibrator plate 2 composed of a plurality of piezoelectric vibrating pieces 24, 25, and 26 and a frame part 29 enclosing the plurality of piezoelectric vibrating pieces 24, 25, and 26 in one body and a plate-shaped lid member 6 and a base member 7 between which the piezoelectric vibrator plate 2 is sandwitched along the thickness, and the frame part 29 and lid member 6, and the frame part 29 and base member 7 are anode-bonded. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrator, a radio timepiece including the same, an oscillator, and an electronic device.

In recent years, various piezoelectric vibrators have been used as time sources, timing sources of control signals, and the like in mobile phones and portable information terminal devices.
In these piezoelectric vibrators, a plurality of piezoelectric vibrating pieces are formed as separate bodies, or a plurality of piezoelectric vibrating pieces are formed integrally with each other, and the plurality of piezoelectric vibrating pieces are packaged by a conductive adhesive. There has been proposed a piezoelectric vibrator bonded to (see, for example, Patent Document 1).
Further, an angular velocity sensor including a piezoelectric vibrator plate in which a plurality of piezoelectric vibrating pieces and a frame-like portion surrounding the plurality of piezoelectric vibrating pieces are integrally formed has been proposed (for example, see Patent Document 2).
JP 2003-258589 A JP-A-8-278142

  However, in the configuration described in Patent Document 1, since a frame-like portion or the like is not provided, it is necessary to mount a plurality of piezoelectric vibrating pieces independently or as separate bodies. There is a problem that it is difficult to mount the piece with an appropriate position and angle with high accuracy. In order to facilitate the mounting, it is conceivable to provide a certain amount of space. However, if these spaces are provided, the overall size increases. Furthermore, since the piezoelectric vibrating reed is bonded with an adhesive, there is a problem that it is easily removed depending on various factors such as impact and deterioration with time.

  Further, in the configuration described in Patent Document 2, since the plurality of piezoelectric vibrating pieces are formed integrally with the frame-like portion, the piezoelectric vibrating piece can be mounted together with the frame-like portion. Although it is easy to mount a plurality of piezoelectric vibrating reeds formed as an adhesive, the piezoelectric vibrator plate is considered to adhere to the package with an adhesive, so that it is still easily removed due to various factors such as impact and deterioration over time. There is a problem.

  The present invention has been made in view of such circumstances, and not only can a plurality of piezoelectric vibrating pieces be mounted with high accuracy and ease, but also a piezoelectric vibrator capable of improving durability. An object of the present invention is to provide a radio timepiece, an oscillator, and an electronic device including the above.

In order to solve the above problems, the present invention provides the following means.
A first configuration of a piezoelectric vibrator according to the present invention includes a piezoelectric vibrator plate in which a plurality of piezoelectric vibrating pieces and a frame-like portion surrounding the plurality of piezoelectric vibrating pieces are integrally formed, and the piezoelectric vibrator A plate-like lid member and a base member that sandwich the plate in the thickness direction, and the frame-like portion and the lid member, and the frame-like portion and the base member are anodically bonded. And

In the first configuration of the piezoelectric vibrator according to the present invention, the piezoelectric vibrator plate is formed by integrally forming a plurality of piezoelectric vibrating pieces and a frame-like portion surrounding the plurality of piezoelectric vibrating pieces. The part and the lid member, and the frame-like part and the base member are anodically bonded. That is, an electrostatic attractive force is generated between the frame-shaped portion and the lid member, and between the frame-shaped portion and the base member, and they are strongly adhered and anodically bonded.
Thereby, the piezoelectric vibrator plate, the lid member, and the base member can be firmly joined.

  In addition, a second configuration of the piezoelectric vibrator according to the present invention includes a pair of vibrating arm portions in which each of the plurality of piezoelectric vibrating pieces extends in parallel with each other and vibrates when a voltage is applied thereto. Each of the pair of vibrating arm portions is provided with a frequency adjusting region for adjusting a resonance frequency, and the frequency adjusting region extends in the length direction of the vibrating arm portion over the plurality of piezoelectric vibrating reeds. They are arranged on the same straight line in the intersecting direction.

  In the second configuration of the piezoelectric vibrator according to the present invention, the resonance frequency of the pair of vibrating arms is adjusted by adjusting the weight of the frequency adjustment region. At this time, since the frequency adjustment region is arranged on the same straight line in a direction intersecting the length direction of the vibrating arm portion, the weight of the frequency adjustment region can be adjusted sequentially. Therefore, the resonance frequency of the pair of vibrating arms can be adjusted quickly and easily.

  The third configuration of the piezoelectric vibrator according to the present invention is characterized in that the frequency adjustment region is a fine adjustment region for finely adjusting the resonance frequency.

In the third configuration of the piezoelectric vibrator according to the present invention, for example, when laser light or the like is irradiated to the fine adjustment region, the member provided in the fine adjustment region is heated and evaporated. Therefore, the weight of the fine adjustment region is adjusted. At this time, for example, the weight of the fine adjustment region is adjusted by moving the light emitting portion of the laser beam along the same straight line.
As a result, it is possible to finely adjust the resonance frequency of the vibrating arm portion more quickly and easily.

  The radio-controlled timepiece according to the invention is characterized in that the filter unit includes any one of the piezoelectric vibrators having the first to third configurations.

  In the radio-controlled timepiece according to the present invention, the same effects as those of the piezoelectric vibrator having any of the first to third configurations can be obtained.

  An oscillator according to the present invention is characterized in that the piezoelectric vibrator having any one of the first to third configurations is electrically connected to an integrated circuit as an oscillator.

  In the oscillator according to the present invention, the same effects as those of the piezoelectric vibrator having any of the first to third configurations can be obtained.

  An electronic apparatus according to the present invention includes the piezoelectric vibrator having any one of the first to third configurations.

  In the electronic device according to the present invention, the same effects as those of the piezoelectric vibrator of any of the first to third configurations can be obtained.

  According to the present invention, since the piezoelectric vibrator plate including the integrally formed piezoelectric vibrating piece and the frame-like portion can be firmly bonded to the lid member and the base member, a plurality of piezoelectric vibrating pieces can be accurately combined. Moreover, not only can it be easily mounted, but also durability can be improved.

(Embodiment 1)
Hereinafter, a crystal resonator (piezoelectric resonator) according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a crystal resonator as a first embodiment. FIG. 2 is an exploded perspective view showing the crystal resonator. FIG. 3 is an enlarged plan view showing a crystal resonator plate in the crystal resonator.
In FIG. 1, reference numeral 1 denotes a crystal resonator.
A crystal resonator 1 includes a crystal resonator plate (piezoelectric resonator plate) 2 made of crystal and formed in a rectangular shape, and a plate-shaped lid that is overlapped and joined in the thickness direction across the crystal resonator plate 2. And a sealed container 3 having a member 6 and a base member 7.

  The lid member 6 and the base member 7 are made of glass such as soda lime glass as shown in FIG. Of the two main surfaces of the lid member 6, a substantially rectangular lid-side recess 11 is formed on one main surface 6 a. Similarly, a substantially rectangular base-side recess 14 is formed on one main surface 7 a of the base member 7. Then, by making the lid member 6 and the base member 7 face each other, a hollow portion is formed in the sealed container 3, and the vibration of the vibrating arm portion described later is allowed by this hollow portion. The airtight container 3 is hermetically sealed, and the cavity is kept in a vacuum state.

  In addition, external terminal connection portions 21 that are notched in an arc shape are provided at the four corners of the base member 7. The external terminal connection portion 21 is provided with an external electrode 20 extending to the bottom surface 7b of the base member 7 (the other main surface of the base member 7). The two external electrodes 20 disposed on one end side in the depth direction D of the base member 7 are electrically connected to each other, and the two external electrodes 20 disposed on the other end side in the depth direction D are connected to each other. Are electrically connected. That is, the pair of external electrodes 20 separated at both ends in the depth direction D function as positive and negative external electrodes for applying a voltage to the crystal resonator plate 2.

Furthermore, the external electrode 20 includes a base metal film to be bonded to the base member 7 and a surface metal film that is provided on the base metal film and forms the surface of the external electrode 20. The base metal film and the surface metal film And a two-layer structure. The base metal film is made of an alloy of nickel (Ni) and chromium (Cr), and is formed by sputtering or vapor deposition. Typical component ratios of nickel and chromium are 80% nickel and 20% chromium by weight. In addition, this weight ratio is an example, Comprising: It can change according to a use. A suitable Cr ratio is 5% to 80%.
The surface metal film is made of gold (Au) and is formed by being deposited on the base metal film by sputtering or vapor deposition.

  In addition, a protective film (not shown) for preventing corrosion of the electrode film 4 described later is formed on the outer peripheral surface of the sealed container 3 except for the bottom surface 7b. The protective film is made of 0.1 wt% fluorocarbon of a fluorine-based coating agent having trimethylsiloxane as a terminal. As the protective film, for example, OPTOOL DSX (product name: manufactured by Daikin Industries, Ltd.) is used.

As shown in FIG. 3, the quartz resonator plate 2 includes tuning-fork type first to third quartz crystal vibrating pieces (piezoelectric vibrating pieces) 24, 25, and 26, and these first to third quartz crystal vibrating pieces 24, And a rectangular frame-shaped portion 29 that surrounds 25 and 26. The first to third quartz crystal vibrating pieces 24, 25, and 26 and the frame portion 29 are integrally formed. The first to third quartz crystal vibrating pieces 24, 25, and 26 are set to have the same thickness dimension. Each of the first to third quartz crystal vibrating pieces 24, 25, and 26 includes a pair of vibrating arm portions 24a, 25a, and 26a extending in parallel to each other and base ends of the pair of vibrating arm portions 24a, 25a, and 26a. And plate-like bases 24b, 25b, and 26b that connect the sides. And the frame-shaped part 29 is integrally connected with the base end side of the base parts 24b, 25b, and 26b. The pair of vibrating arm portions 24a, 25a, and 26a vibrate at a predetermined frequency by applying a voltage.
The resonance frequency of the first crystal vibrating piece 24 is set to 40 kHz, the resonance frequency of the second crystal vibrating piece 25 is set to 60 kHz, and the resonance frequency of the third crystal vibrating piece 26 is set to 77.5 kHz. ing. The first to third quartz crystal vibrating pieces 24, 25, and 26 are arranged in the width direction W and are electrically connected in parallel.

On the front and back surfaces of the crystal resonator plate 2, there are formed electrode films 4 for exciting the vibration arm portions 24a, 25a and 26a by applying a voltage. The electrode film 4 is made of a conductive member such as aluminum, and is patterned according to various specifications and shapes. Moreover, the area | region of the front-end | tip part of vibration arm part 24a, 25a, 26a becomes frequency adjustment area | region 24c, 25c, 26c for adjusting the resonance frequency of vibration arm part 24a, 25a, 26a, These frequency adjustment area | regions 24c, 25c, and 26c are provided with an aluminum film. That is, the aluminum film and the electrode film 4 in the frequency adjustment regions 24c, 25c, and 26c are integrally formed, but the base end side functions as the electrode film 4 from the distal end portion, and the distal end portions are the frequency adjustment regions 24c, 25c. , 26c. The frequency adjustment areas 24c, 25c, and 26c are composed of coarse adjustment areas 24d, 25d, and 26d on the front end side, and fine adjustment areas 24e, 25e, and 26e.
Reference numeral 5 denotes a through hole for conducting the front and back electrode films 4.

Next, a method for manufacturing the crystal unit 1 in the present embodiment will be described.
FIG. 4 is a flowchart showing the procedure of the method for manufacturing the crystal unit 1.
First, a quartz crystal ore is subjected to polishing or the like, cut at a predetermined cut angle, and washed to form a disk-shaped piezoelectric wafer (step S10). Then, a plurality (n sets) of first to third crystal vibrating pieces 24, 25, and 26 are formed in the matrix direction by etching or the like on the piezoelectric wafer (step S11). Then, a film made of aluminum is formed on the front and back surfaces of the piezoelectric wafer by sputtering or vapor deposition. Further, patterning is performed by photolithography, etching, or the like to form the electrode film 4 and the aluminum films of the frequency adjustment regions 24c, 25c, and 26c. In the coarse adjustment step, the resonance frequency of each of the vibrating arm portions 24a, 25a, and 26a is roughly adjusted. That is, trimming is performed by irradiating the aluminum film in the coarse adjustment regions 24d, 25d, and 26d with a laser to evaporate a part of the aluminum film. As a result, the resonance frequencies of the respective vibrating arm portions 24a, 25a, and 26a are adjusted to the vicinity of the desired resonance frequency.

Further, the glass is polished, washed, etched, etc., to form a disk-shaped lid wafer (step S20). A plurality of lid-side recesses 11 are formed in the matrix direction on the lid wafer by photolithography and etching (step S21). Then, a V-shaped bevel cut is formed in the matrix direction as a guide groove when the lid wafer is cut later on the lid wafer (step S22).
Further, the glass is polished, washed, etched, etc. to form a disk-shaped base wafer (step S30). A plurality of base-side recesses 14 arranged in the matrix direction are formed on the base wafer by photolithography, etching, and the like (step S31). Then, through holes for forming external electrodes are formed on the base wafer by blasting or the like (step S32). This through hole for forming an external electrode is divided into four parts in a cutting process to be described later, and becomes an external terminal connection part 21 cut out in an arc shape. Further, a bevel cut having a V-shaped cross section is formed in the matrix direction on the base wafer (step S33).

  Then, in the alignment step, the piezoelectric wafers are stacked in a predetermined position so as to be sandwiched between the lid wafer and the base wafer in the thickness direction (step S40). At this time, the respective lid-side recesses 11 and the base-side recesses 14 face each other, thereby forming a cavity.

  Then, in the bonding process, the three superposed wafers are put into an anodic bonding apparatus, and anodic bonding is performed by applying a predetermined voltage in a predetermined temperature atmosphere (step S41). That is, when a positive potential (usually ground potential) is supplied to one point of the piezoelectric wafer, all of the electrode films 4 formed on the front and back surfaces of the piezoelectric wafer are applied to the same potential. A negative potential conductive electrode is uniformly adhered to the non-bonding surface side (surface side) of each of the lid wafer and the base wafer, and an electric field is generated between the electrode film 4 and the conductive electrode. . By application of thermal energy and electric field energy, the electrode film 4 provided at a portion corresponding to the frame-shaped portion 29 is bonded to the lid wafer and the base wafer.

Next, in the external electrode forming step, a metal mask is applied to the bottom surface (surface, non-bonded surface) of the base wafer, and the external electrode 20 is formed by sputtering or vapor deposition (step S42). The external electrode 20 becomes a pair of positive and negative external electrodes 20 that are electrically connected to the electrode film 4 and extend to the bottom surface of the base wafer.
Then, in the cutting process, the bonded lid wafer, piezoelectric wafer, and base wafer are fully cut in the matrix direction along the bevel cut (step S43). As a result, the crystal unit 1 is cut one by one.

Further, in the fine adjustment step, the resonance frequency is finely adjusted for the individually cut crystal units 1 (step S44). That is, trimming is performed by irradiating the aluminum film in the fine adjustment regions 24e, 25e, and 26e with a laser to evaporate a part of the film in the fine adjustment region. As a result, the resonance frequencies of the respective vibrating arm portions 24a, 25a, and 26a can be adjusted to a desired resonance frequency with high accuracy.
Then, in the coating process, a protective film is formed on the outer peripheral surface of the sealed container 3 except for the bottom surface 7b (step S45).
Thus, the crystal resonator 1 shown in FIG. 1 is obtained.

  In such a crystal resonator 1, when a predetermined voltage is applied to the external electrode 20, the voltage is applied to the vibrating arm portions 24 a, 25 a, and 26 a through the electrode film 4. Then, due to the piezoelectric effect, the vibrating arms 24a, 25a, 26a bend (vibrate) with a predetermined frequency in a direction in which they approach or separate from each other, that is, in a reverse phase mode. When the vibrating arm portions 24a, 25a, and 26a vibrate, the vibrations are converted into electric signals by the piezoelectric characteristics of the crystal. Thereby, a highly accurate and stable frequency signal can be obtained.

As described above, according to the crystal resonator 1 in the present embodiment, the first to third crystal vibrating pieces 24a, 25a, and 26a and the frame-shaped portion 29 are integrally formed, so that the first to third The crystal vibrating pieces 24a, 25a, and 26a can be mounted with high accuracy and ease. Further, since the crystal resonator plate 2 and the lid member 6 and the crystal resonator plate 2 and the base member 7 can be strongly bonded by anodic bonding, the first may be caused by factors such as impact and deterioration over time. The third crystal vibrating pieces 24a, 25a, 26a can be prevented from coming off. Therefore, the durability of the crystal unit 1 can be improved and its soundness can be maintained for a long time.
Moreover, since anodic bonding is performed, an aging step for solidifying the adhesive and degassing can be eliminated.

Here, a method for setting the dimensions of each resonator element constituting the crystal unit 1 according to the present embodiment will be described. When one crystal unit 1 is installed, three conventional cylinder packages are arranged. How the installation space changes depending on the case will be described. This will be described with reference to FIG. FIG. 5 is an explanatory diagram showing a part of the size of the resonator element constituting the crystal resonator in the present embodiment.
As described above, the resonance frequency of the first crystal vibrating piece 24 is set to 40 kHz. The second crystal vibrating piece 25 is set to 60 kHz, and the third crystal vibrating piece 26 is set to 77.5 kHz.
The approximate dimension of the dimension value (L2) of each vibrating arm can be obtained according to a well-known equation representing the resonance frequency of a tuning fork vibrator in which a pair of vibrating arms vibrate in a bending mode. That is, the resonance frequency is proportional to the width (W1) of the vibrating arm and inversely proportional to the square of the length (L2) of the vibrating arm. The pair of vibrating arms are designed to have the same width, and the length of the vibrating arm is a dimension value from the bottom side of the fork to the tip. Here, the width dimensions of the vibrating arms of the three frequencies are designed to be the same dimension value. Therefore, the length of the vibrating arm having the lowest frequency of 40 KHz is the longest dimension value, and the length of the vibrating piece of the third vibrator having the highest frequency is the shortest.
In the present invention, from the viewpoint of management of the width dimension in the manufacturing process as described above, the width of the vibrating arm of the three frequencies is designed to be a common value (W1), and the width dimension (W2) of the base portion is also set. It set so that it might become the same dimension. The width of the base is slightly larger than the total width of the two arms (twice W1) and the distance between the arms. This is a well-known measure against vibration leakage. The vibration leakage will be described next.

The dimension value (L1) indicating the length of the base was set for each frequency. The dimension value L1 is determined from the characteristics of vibration leakage and stability against fluctuations in driving power applied to the vibrator. The characteristic of vibration leakage is a characteristic indicating how much the resonance frequency and the resonance resistance value change when a static load of about 10 N, for example, is applied from the outside to the housing of the completed vibrator. When vibration leakage occurs, the resonance frequency changes by several ppm when a load is applied. In this vibrator, L1 was set so as to be within ± 1 ppm.
In addition, the stability with respect to the driving power was set such that even when a power in a range corresponding to 0.1 μW to about 5 μW was applied, the resonance frequency and the resonance resistance value were small and stable within this power range.
Thus, the optimum base length (L1) at each frequency was determined from simulation and experimental data so as to satisfy the stability of vibration leakage characteristics and applied power characteristics.

The total length (L1 + L2) of the base length (L1) set as described above and the length (L2) of the vibrating arm set in advance is the total length of the vibrating piece. As the total length, the lowest frequency, 40 KHz, is the longest, about 3.1 mm, and the highest frequency, 77.5 KHz, is the shortest.
The thickness dimensions (plate thickness) of the first to third quartz crystal vibrating pieces 24, 25, and 26 are all the same. Furthermore, the cut angles when forming the piezoelectric wafer are all set to 1 °.

Further, regarding the overall size of the crystal unit 1, as shown in FIG. 1, the width dimension (short side part) in the width direction W is 2.8 mm, and the depth dimension (long side part) in the depth direction D is 4.0 mm. The height dimension is set to 1.0 mm. Here, referring to the figure, the size of the crystal unit 1 will be compared with the conventional product. FIG. 6 is an explanatory diagram showing the floor area, volume, and weight of the crystal resonator according to the present embodiment and the conventional cylinder package as a table. FIG. 7 is an explanatory view showing a size portion of a conventional cylinder type package.
As shown in FIG. 6, the floor area of the crystal unit 1 is 11.2 mm ² due to the product of the width dimension (2.8 mm) and the depth dimension (4.0 mm), and the volume is the width dimension (2. 8 mm), the depth dimension (4.0 mm), and the height dimension (1.0 mm) are 11.2 mm ³ . The weight is set to 25 mg.

On the other hand, in the conventional general cylinder type package, as shown in FIG. 7, the diameter φ (height dimension) of the package body is 1.2 mm, and the length dimension L′ 1 of the package body is 4.6 mm. The overall length L′ 2 is set to 6.5 mm. Assuming that three cylinder-type packages are arranged in parallel, the overall length dimension is 6.5 mm, but the overall width dimension orthogonal to the length direction is 3.6 mm, three times 1.2 mm. Become.
Therefore, as shown in FIG. 6, the floor area is 23.4 mm ² by the product of the overall length dimension (6.5 mm) and the overall width dimension 3.6 mm, and the volume is 5 mm. In other words, 21.6 mm ³ is obtained from the product of the overall width dimension of 3.6 mm and the diameter φ (1.2 mm). The weight is 48 mg.

From the above results, it can be seen that the floor area, volume, and weight of the crystal unit 1 are reduced to about 50%, respectively, as compared with the case where three conventional cylindrical packages are arranged. Thereby, further miniaturization and weight reduction can be achieved compared with the conventional cylinder type package.
When the resonance frequency of the crystal vibrating piece is 68.5 kHz, when the same vibrating arm width (W1) as 40 kHz or the like is used, the value of (L1 + L2) indicating the total length of the vibrating piece is 77.5 kHz. Longer than 60 kHz. Therefore, even when 68.5 kHz is selected, it can be accommodated in the package having the depth dimension (4.0 mm) described above, and thus the effect that it is more advantageous than the case where it is accommodated in the cylinder type package is similarly established. The width (W2), thickness (plate thickness), and cut angle of the base are also set to the same values as the other frequencies described above.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a front view showing a crystal resonator plate as a second embodiment. In FIG. 8, the same components as those shown in FIGS. 1 to 7 are denoted by the same reference numerals, and the description thereof is omitted.
This embodiment and the first embodiment have the same basic configuration, and only the differences will be described here.

  In the present embodiment, the fine adjustment regions 24e, 25e, and 26e provided in the respective vibrating arm portions 24a, 25a, and 26a are aligned in a direction intersecting the length direction of the vibrating arm portions 24a, 25a, and 26a. . That is, the fine adjustment regions 24e, 25e, and 26e are arranged on a virtual straight line R that is directed in a direction (width direction W) that intersects the length direction of the vibrating arm portions 24a, 25a, and 26a.

Under such a configuration, the light emitting unit of the fine adjustment laser is irradiated from the light emitting unit by moving the vibrating arm units 24a, 25a, and 26a in the width direction W while suppressing the movement in the length direction. The laser is sequentially irradiated onto the fine adjustment regions 24e, 25e, and 26e.
As described above, an increase in tact time in the fine adjustment process can be suppressed, and the resonance frequencies of the vibrating arm portions 24a, 25a, and 26a can be adjusted quickly and easily.

(Embodiment 3)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a front view showing a crystal resonator plate as a third embodiment. In FIG. 9, the same components as those shown in FIGS. 1 to 8 are denoted by the same reference numerals, and the description thereof is omitted.
This embodiment and the first embodiment have the same basic configuration, and only the differences will be described here.

  In the present embodiment, in addition to the first to third quartz crystal vibrating pieces 24, 25, and 26, a fourth quartz crystal vibrating piece (piezoelectric vibrating piece) 27 is provided. A connecting portion 29 a extending in the width direction W is provided at a substantially central portion in the depth direction D of the frame-shaped portion 29, whereby two installations arranged in the depth direction D are arranged in the frame-shaped portion 29. Spaces 31 and 32 are formed. In one installation space 32, the first and second crystal vibrating pieces 24 and 25 are arranged in the width direction W. The first and second quartz crystal vibrating pieces 24 and 25 are directed outward in the depth direction D with respect to the coupling portion 29a when the base portions 24b and 25b are integrally connected to the coupling portion 29a. . In the other space 31, third and fourth crystal vibrating pieces 26 and 27 are arranged in the width direction W. The third and fourth crystal vibrating pieces 26 and 27 are directed outward in the depth direction D with respect to the connecting portion 29a by connecting the base portions 26b and 27b integrally to the connecting portion 29a. .

The resonance frequencies of the first to third crystal vibrating pieces 24, 25, and 26 are set to 40 kHz, 60 kHz, and 77.5 kHz as described above, and the resonance frequency of the fourth crystal vibrating piece 27 is 68. .5 kHz is set. The first to fourth quartz crystal vibrating pieces 24, 25, 26, and 27 are electrically connected in parallel.
From the above, not only the same effects as in the first embodiment can be obtained, but also more frequencies can be handled, and installation efficiency can be improved.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a front view showing a crystal resonator plate as a fourth embodiment. 10, the same components as those shown in FIGS. 1 to 7 are denoted by the same reference numerals, and the description thereof is omitted.
This embodiment and the first embodiment have the same basic configuration, and only the differences will be described here.

In the present embodiment, first and second crystal vibrating pieces 24 and 25 are provided in the frame-shaped portion 29. The first crystal vibrating piece 24 is oriented in the depth direction D, and the second crystal vibrating piece 25 is installed so as to be inclined with respect to the first crystal vibrating piece 24 so that the tip is separated. Yes. By providing the inclination in this way, the second crystal vibrating piece has a temperature characteristic different from that of the first crystal vibrating piece.
Conventionally, it has been known that when two tuning fork type vibrators having different frequency temperature characteristics with the resonance frequency adjusted equally are connected in parallel, the temperature characteristics are superior to the temperature characteristics of the crystal unit alone. However, since the external terminals or leads of the two vibrators housed in independent containers are connected in parallel, there is a disadvantage that the entire volume increases. Since the crystal resonator 1 in this embodiment is accommodated in one container, the volume can be significantly reduced.
Further, since the two vibrating pieces are disposed close to each other in the same container, the temperatures of the two vibrating pieces can be regarded as being substantially equal. Therefore, it is possible to provide a vibrator having excellent reproducibility of the relationship between frequency and temperature over a wide temperature range.

(Embodiment 5)
Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a block diagram showing a radio timepiece as a fifth embodiment.
In the present embodiment, a radio timepiece including the above-described piezoelectric vibrator in a filter unit will be described. In FIG. 11, reference numeral 71 denotes a radio timepiece according to the fifth embodiment of the present invention.

  The radio clock 71 is a clock having a function of receiving a standard radio wave including time information and automatically correcting and displaying the correct time. In Japan, there are transmitting stations (transmitting stations) that transmit standard radio waves to Fukushima Prefecture (40 kHz) and Saga Prefecture (60 kHz), each transmitting standard radio waves. Long waves such as 40 kHz or 60 kHz have the property of propagating on the ground surface and the property of propagating while reflecting the ionosphere and the ground surface, so the propagation range is wide, and the above two transmitting stations cover all of Japan. .

Here, the functional configuration of the radio timepiece 71 will be described with reference to FIG.
The antenna 74 receives the long standard radio wave of 40 kHz or 60 kHz. The long standard radio wave is obtained by subjecting time information called a time code to AM modulation on the 40 kHz or 60 kHz carrier wave.
The received long standard wave is amplified by the amplifier 75 and filtered and tuned by the filter unit 76 having the crystal unit 1. The crystal resonator 1 includes first and second crystal vibrating pieces 24 and 25 having resonance frequencies of 40 kHz and 60 kHz that are the same as the carrier frequency.
Further, the filtered signal having a predetermined frequency is detected and demodulated by the detection and rectification circuit 81. Subsequently, the time code is taken out via the waveform shaping circuit 84 and counted by the CPU 85. The CPU 85 reads information such as the current year, accumulated date, day of the week, and time. The read information is reflected on the RTC 86, and accurate time information is displayed.

Since the carrier wave is 40 kHz or 60 kHz, the first and second crystal vibrating pieces 24 and 25 preferably have the tuning fork type structure described above.
In the circuit block diagram shown in FIG. 11, the first and second crystal vibrating pieces 24 and 25 having resonance frequencies of 40 kHz and 60 kHz are respectively drawn in parallel. In the present invention, since the tuning fork type crystal vibrating piece corresponding to these two frequencies can be stored in one package, the mounting area is greatly increased compared to the case of mounting two vibrators stored in separate containers. It is possible to reduce it. Therefore, it is particularly suitable for electronic devices that require downsizing, such as watches and portable devices.

Although the above description has been given with an example in Japan, the frequency of the long standard radio wave is different overseas. For example, in Germany, a standard radio wave of 77.5 kHz is used. Therefore, when a radio timepiece that can be handled overseas is incorporated into a portable device, a crystal resonator having a frequency different from that in Japan is required. In this case, if the crystal resonator 1 in the first embodiment is used, the first to third crystal vibrating pieces 24, 25, and 26 can handle frequencies of 40 kHz, 60 kHz, and 77.5 kHz. it can.
As described above, since the radio-controlled timepiece 71 in which a plurality of vibrating pieces are housed in one package is configured using the present invention, compared to the case where a plurality of vibrators housed in individual containers are mounted. It has become possible to significantly reduce the mounting area and volume. Since the quartz resonator plate 2 in which the quartz vibrating piece and the frame-shaped portion are integrally formed is anodically bonded, the radio-controlled timepiece can function with stable accuracy over a long period of time.

(Embodiment 6)
Next, an example of an oscillator as Embodiment 6 according to the present invention will be described with reference to FIG. FIG. 12 is a schematic configuration diagram illustrating an oscillator including the crystal resonator according to any one of Embodiments 1 to 4 according to the present invention.
As shown in FIG. 12, the oscillator 90 of the present embodiment is configured by configuring the crystal unit 1 as an oscillator electrically connected to an integrated circuit 91. The oscillator 90 includes a substrate 93 on which an electronic component 92 such as a capacitor is mounted. On the substrate 93, the integrated circuit 91 for the oscillator is mounted, and the crystal vibrating piece 1 is mounted in the vicinity of the integrated circuit 91. The electronic component 92, the integrated circuit 91, and the piezoelectric vibrator 90 are electrically connected by a wiring pattern (not shown). Each component is molded with a resin (not shown).

In the oscillator 90 configured as described above, when a voltage is applied to the crystal resonator 1, the crystal resonator element in the crystal resonator 1 vibrates, and this vibration is converted into an electrical signal by the piezoelectric characteristics of the crystal, It is input to the integrated circuit 91 as an electrical signal. The input electrical signal is subjected to various processes by the integrated circuit 91 and output as a frequency signal. Thereby, the crystal unit 1 functions as an oscillator.
Further, by selectively setting the configuration of the integrated circuit 91, for example, an RTC (real-time clock) module or the like as required, the operation date and time of the device and external device in addition to a single-function oscillator for a clock, etc. A function for controlling the time, providing a time, a calendar, and the like can be added.

  As described above, according to the oscillator 90 of the present embodiment, since the small-sized quartz crystal resonator 1 having a plurality of integrally formed crystal vibrating pieces and having excellent durability is provided, the oscillator 90 itself is also downsized. And durability can be improved, and the reliability of the product can be improved. In addition to this, it is possible to obtain a highly accurate frequency signal that is stable over a long period of time.

(Embodiment 7)
Next, as Embodiment 7 according to the present invention, a portable information device will be described as an example of an electronic device in which a crystal unit is connected to a timer unit.
First, as a premise, the portable information device according to the present embodiment is a development and improvement of a wrist watch in the prior art. The appearance is similar to that of a wristwatch, and a liquid crystal display is arranged in a portion corresponding to the dial so that the current time and the like can be displayed on this screen. When used as a communication device, it can be removed from the wrist and communicated in the same manner as a conventional mobile phone by a speaker and a microphone built in the band. However, it is much smaller and lighter than conventional mobile phones.

Next, a functional configuration of the portable information device according to the embodiment of the present invention will be described with reference to FIG. FIG. 13 is a block diagram functionally showing an example of the configuration of a portable information device using the crystal resonator according to any one of Embodiments 1 to 4 according to the present invention connected to a timer unit.
As illustrated in FIG. 13, the portable information device 100 includes a power supply unit 101 that supplies power to each functional unit. Specifically, the power supply unit 101 is realized by a lithium ion secondary battery. A control unit 102, a timing unit 103, a communication unit 104, a voltage detection unit 105, and a display unit 107, which will be described later, are connected in parallel to the power supply unit 101, and power is supplied from the power supply unit 101 to each functional unit.

  The control unit 102 controls each function unit to be described later, and performs operation control of the entire system such as transmission and reception of audio data, measurement and display of the current time, and the like. Specifically, the control unit 102 is realized by a program written in advance in a ROM, a CPU that reads and executes the program, a RAM that is used as a work area of the CPU, and the like.

The timer 103 includes an integrated circuit that includes an oscillation circuit, a register circuit, a counter circuit, an interface circuit, and the like, and the crystal unit 1. When a voltage is applied to the crystal unit 1, the above-mentioned crystal unit piece vibrates, and the vibration is converted into an electric signal by the piezoelectric characteristics of the crystal and input to an oscillation circuit formed by a transistor and a capacitor. The output of the oscillation circuit is binarized and counted by a register circuit and a counter circuit. Signals are transmitted / received to / from the control unit 102 via the interface circuit, and the current time, current date, calendar information, and the like are displayed on the display unit 107.
The timer unit 51 includes an integrated circuit including an oscillation circuit, a register circuit, a counter circuit, an interface circuit, and the like, and the crystal unit 1. When a voltage is applied to the crystal unit 1, any one of the above-described crystal vibrating pieces 24, 25, and 26 vibrates, and the vibration is converted into an electric signal by the piezoelectric characteristics of the crystal, and is sent to the oscillation circuit as an electric signal. Entered. The output of the oscillation circuit is binarized and counted by a register circuit and a counter circuit. Then, signals are transmitted to and received from the control unit 48 via the interface circuit, and the current time, current date, calendar information, and the like are displayed on the display unit 56.

  The communication unit 104 has functions similar to those of a conventional mobile phone, and includes a radio unit 104a, a voice processing unit 104b, an amplification unit 104c, a voice input / output unit 104d, a ring tone generation unit 104e, a switching unit 104f, and a call control memory. Part 104g and telephone number input part 104h.

  The wireless unit 104a transmits and receives various data such as voice data to and from the base station via the antenna. The audio processing unit 104b encodes and decodes an audio signal input from the radio unit 104a or an amplification unit 104c described later. The amplifying unit 104c amplifies the signal input from the audio processing unit 104b or the audio input / output unit 104d described later to a predetermined level. The voice input / output unit 104d is specifically a speaker and a microphone, and amplifies a ringtone and a received voice or collects a speaker voice.

  In addition, the ring tone generator 104e generates a ring tone in response to a call from the base station. The switching unit 104f switches the amplifying unit 104c connected to the voice processing unit 104b to the ringing tone generating unit 104e only when an incoming call is received, so that the generated ringing tone is transmitted to the voice input / output unit 104d via the amplifying unit 104c. Output to.

  The call control memory 104g stores a program related to incoming / outgoing call control of communication. The telephone number input unit 104h is specifically composed of 0 to 9 number keys and some other keys, and inputs the telephone number of the destination.

  The voltage detection unit 105 detects the voltage drop and notifies the control unit 102 when the voltage applied to each functional unit including the control unit 102 by the power supply unit 101 falls below a predetermined value. To do. The predetermined voltage value is a value set in advance as a minimum voltage necessary for stably operating the communication unit 104, and is, for example, a voltage of about 3V. Upon receiving the voltage drop notification from the voltage detection unit 105, the control unit 102 prohibits the operations of the radio unit 104a, the voice processing unit 104b, the switching unit 104f, and the ring tone generation unit 104e. In particular, it is essential to stop the operation of the wireless unit 104a with high power consumption. At the same time, the display unit 107 displays that the communication unit 104 has become unusable due to insufficient battery power.

The operation of the communication unit 104 can be prohibited by the functions of the voltage detection unit 105 and the control unit 102, and a message to that effect can be displayed on the display unit 107.
As the present embodiment, the function of the communication unit can be stopped in a more complete form by providing the power cutoff unit 106 that can selectively cut off the power supply of the part related to the function of the communication unit.

The display indicating that the communication unit 104 has become unusable may be made by a text message, but more intuitively by a method such as marking the phone icon on the display unit 107 with a cross (X). Good.
According to the portable information device 100 of the present embodiment, since the small crystal resonator 1 having a plurality of integrally formed crystal vibrating pieces and having excellent durability is provided, the portable information device 100 itself can be downsized. Durability can be improved and product reliability can be improved. In addition to this, it is possible to obtain time information that is stable and accurate over a long period of time.

In the first to seventh embodiments, the piezoelectric vibrating piece is a quartz vibrating piece made of quartz. However, the present invention is not limited to this, and the vibrator is made of various piezoelectric single crystal materials such as lithium niobate. It may be a piece.
Further, although the electrode film 4 is made of aluminum, the present invention is not limited to this, and other conductive members may be used.
Furthermore, although the aluminum film is provided in the frequency adjustment regions 24c, 25c, and 26c, the present invention is not limited to this, and other members may be used. In addition, although the aluminum film is formed integrally with the electrode film 4, the present invention is not limited to this, and a metal weight may be provided separately.

In addition, the number of crystal vibrating pieces installed can be changed as appropriate.
Furthermore, although the setting example and the frequency of the size of the resonator element of the crystal unit 1 have been described, the setting example and the frequency are examples, and the numerical values can be changed as appropriate.
Moreover, although the protective film is made of the OPTOOL DSX, the present invention is not limited to this, and the member can be appropriately changed.
In addition, although the base metal film of the external electrode is made of chromium, it is not limited to this, and the member can be changed as appropriate. For example, titanium (Ti) or tantalum (Ta) may be used.
In addition, although the surface metal film of the external electrode is made of gold, it is not limited to this, and the member can be appropriately changed. For example, platinum may be used.

Furthermore, in the second embodiment, the fine adjustment regions 24e, 25e, and 26e are aligned on the virtual straight line R. However, the present invention is not limited to this, and the coarse adjustment regions 24d, 25d, and 26d are aligned on the virtual straight line R. May be aligned.
The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 is a perspective view showing a crystal resonator as a first embodiment of the present invention. It is a perspective view which decomposes | disassembles and shows the crystal oscillator of FIG. FIG. 2 is an enlarged plan view showing a crystal resonator plate of FIG. 1. 2 is a flowchart showing a procedure of a manufacturing method of the crystal unit of FIG. It is explanatory drawing which shows the site | part of the dimension of the quartz crystal vibrating piece of FIG. It is explanatory drawing which shows the floor area, volume, and weight of the quartz oscillator of FIG. 1, and the conventional cylinder type package as a table | surface. It is explanatory drawing which shows the site | part of the size of the conventional cylinder type package. It is a front view which shows the crystal oscillator plate as the 2nd Embodiment of this invention. It is a front view which shows the crystal oscillator plate as the 3rd Embodiment of this invention. It is a front view which shows the crystal oscillator plate as the 4th Embodiment of this invention. It is a block diagram which shows the radio timepiece as the 5th Embodiment of this invention. It is a schematic block diagram which shows the structure of the oscillator as the 6th Embodiment of this invention. It is a block diagram which shows one example of a structure of the portable information device as the 7th Embodiment of this invention functionally.

Explanation of symbols

1 Crystal resonator (piezoelectric resonator)
2 Crystal oscillator plate (piezoelectric oscillator plate)
6 Lid member 7 Base member 24 First crystal vibrating piece (piezoelectric vibrating piece)
24a Vibrating arm portion 24c Frequency adjustment area 24e Fine adjustment area 25 Second crystal vibrating piece (piezoelectric vibrating piece)
25a Vibrating arm portion 25c Frequency adjustment area 25e Fine adjustment area 26 Third crystal vibrating piece (piezoelectric vibrating piece)
26a Vibrating arm portion 26c Frequency adjustment area 26e Fine adjustment area 27 Fourth crystal vibrating piece (piezoelectric vibrating piece)
27a Vibrating arm portion 27c Frequency adjustment region 27e Fine adjustment region 29 Frame portion 71 Radio wave clock 76 Filter portion 90 Oscillator 91 Integrated circuit 92 Electronic component 93 Substrate 100 Portable information device (electronic device)
DESCRIPTION OF SYMBOLS 101 Power supply part 102 Control part 103 Timekeeping part 104 Communication part 104a Radio | wireless part 104b Voice processing part 104c Amplification part 104d Voice input part 104e Ringing tone generation part 104f Switching part 104g Call control memory part 104h Telephone number input part 105 Voltage detection part 106 Power supply Blocking unit 107 Display unit

Claims (6)

A piezoelectric vibrator plate in which a plurality of piezoelectric vibrating pieces and a frame-like portion surrounding the plurality of piezoelectric vibrating pieces are integrally formed;
A plate-like lid member and a base member sandwiching the piezoelectric vibrator plate in the thickness direction,
The piezoelectric vibrator, wherein the frame-shaped portion and the lid member, and the frame-shaped portion and the base member are anodically bonded. Each of the plurality of piezoelectric vibrating pieces is
A pair of vibrating arms that extend in parallel with each other and vibrate when a voltage is applied;
Each of the pair of vibrating arm portions is provided with a frequency adjustment region for adjusting a resonance frequency,
2. The piezoelectric vibrator according to claim 1, wherein the frequency adjustment regions are arranged on the same straight line across the plurality of piezoelectric vibrating pieces in a direction intersecting a length direction of the vibrating arm portion.   The piezoelectric vibrator according to claim 2, wherein the frequency adjustment region is a fine adjustment region for finely adjusting a resonance frequency.   A radio timepiece comprising the piezoelectric vibrator according to claim 1 in a filter portion.   4. An oscillator, wherein the piezoelectric vibrator according to claim 1 is electrically connected to an integrated circuit as an oscillator.   An electronic apparatus comprising the piezoelectric vibrator according to any one of claims 1 to 3.

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