JP2019012987A - Piezoelectric vibrator and piezoelectric unit - Google Patents

Abstract

To provide a tuning fork type vibrator.SOLUTION: A tuning fork type vibrator 100 includes a base portion 30, tuning fork arms 10, 20 connected to the base portion, and frames 1-4. The tuning fork arms include respective first vibration portions 11, 21 each having a first width W and a first length L, and respective second vibration portions 13, 23 each having a second width We greater than W and a second length Le smaller than L. Groove 12, 22 are formed to at least one face of the upper face and the lower face of the respective first vibration portions 11, 21. A first frame portion and a second frame portion are formed outside the respective tuning fork arms to be extended in a direction common with the tuning fork arms, the first frame portion being connected to the second frame portion via a third frame portion and a fourth frame portion. The base portion is connected to the third frame portion via a connection portion. When the sum of lengths of an outer side face from the first frame portion to the fourth frame portion is defined as a first length dimension Lo and the sum of lengths of an inner side face is defined as a second length dimension Li, 2.4 mm≤Lo≤5 mm and 1.6 mm≤Li≤4.2 mm are satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention includes a tuning fork type piezoelectric vibrator (tuning fork type piezoelectric vibrator), a piezoelectric unit including the tuning fork type piezoelectric vibrator, a case, and a lid, and a piezoelectric oscillation circuit including the piezoelectric unit. The present invention relates to a piezoelectric oscillator, an electronic apparatus including the piezoelectric oscillator, and a manufacturing method thereof.

の位置に形成されていることが記載されている。この形状で、かつ、従来のケースの内部の固定部に固定した方法では、基本波モード振動の発振周波数が、例えば約３２．７６８ｋＨｚで、その周波数での等価直列抵抗Ｒ_１の増加を抑え、かつ、ある程度の小型化（例えば、全長が２ｍｍ程度の水晶ユニット）を図ることができるが、全長が１．３５ｍｍに等しいか、あるいは、１．３５ｍｍより小さいより小型化された水晶ユニットを実現するには、

直列抵抗Ｒ_１が全長２ｍｍの水晶ユニットの等価直列抵抗の２倍以上と極めて大きな等価直列抵抗となると共に、バラツキも大きくなり、等価直列抵抗Ｒ_１の増加を抑制した音叉腕のより短い超小型の音叉型水晶振動子を実現することは極めて困難であった。同時に、音叉型水晶振動子の長さを短く小型化すると等価インダクタンスＬ１が大きくなり、その振動子で発振器を構成し、その発振器の電源をオンにしたときに、その発振器の出力信号の立ち上がり時間（Ｌ１に比例する）、いわゆる起動時間が長くなるという課題が残されていた。
特開２００３−４３６３１０ For example, in paragraph 0035 of Patent Document 1, the first width W is set at a position about half of the tip from the base side.

It is described that it is formed at the position. With this shape and the method fixed to the fixed part inside the conventional case, the oscillation frequency of the fundamental mode vibration is, for example, about 32.768 kHz, and an increase in the equivalent series resistance R ₁ at that frequency is suppressed, In addition, a certain size reduction (for example, a crystal unit having a total length of about 2 mm) can be achieved, but a more compact crystal unit having a total length equal to 1.35 mm or smaller than 1.35 mm is realized. In

With a series resistor R ₁ is extremely large equivalent series resistance twice or more the equivalent series resistance of the quartz unit of full length 2 mm, the variation becomes large, the shorter micro tuning fork arm which can suppress an increase in equivalent series resistance R ₁ It was extremely difficult to realize a tuning fork crystal resonator. At the same time, when the tuning fork crystal unit is shortened and reduced in size, the equivalent inductance L1 increases, and when the oscillator is constituted by the resonator and the oscillator is turned on, the rise time of the output signal of the oscillator The problem that the so-called start-up time becomes long (proportional to L1) remains.
JP 2003-436310 A

  For this reason, in order to realize an ultra-compact tuning fork type piezoelectric vibrator having a shorter tuning fork arm having a small equivalent inductance L1 while suppressing an increase in the equivalent series resistance R1, a new tuning fork type piezoelectric vibrator is provided. A piezoelectric unit including the tuning fork type piezoelectric vibrator, a lid, and a case, a piezoelectric oscillator including the piezoelectric unit, an amplifier, a capacitor, and a resistor, and an electron including the piezoelectric oscillator Devices and methods for their production have been desired.

  In particular, a new-form tuning fork crystal resonator using quartz as a piezoelectric material, a crystal unit including the tuning fork crystal resonator, a crystal oscillator including the crystal unit, and an electronic device including the crystal oscillator, Their manufacturing method has been desired.

  The present invention includes an ultra-compact tuning fork type piezoelectric (crystal) vibrator, a tuning fork type piezoelectric (crystal) vibrator, a lid, and a case that vibrate in a bending mode that advantageously solves the conventional problems by the following method. A piezoelectric (quartz) unit configured, a piezoelectric (quartz) oscillator configured including the piezoelectric (quartz) unit, an amplifier, a capacitor, and a resistor; and an electronic device including the piezoelectric (quartz) oscillator An object of the present invention is to provide a manufacturing method thereof.

That is, the first aspect of the piezoelectric vibrator of the present invention is a tuning fork vibrator comprising a base portion, at least a first tuning fork arm and a second tuning fork arm connected to the base portion, and a frame. Each tuning fork arm of the first tuning fork arm and the second tuning fork arm has a first width and a first length, a first vibrating portion, a second width greater than the first width, and a second length smaller than the first length. And at least one second vibration part, and a groove is formed on at least one of an upper surface and a lower surface of the first vibration part, and the frame includes at least a first frame part, a second frame part, and a third frame. The first frame portion and the second frame portion extend in the same direction as the first tuning fork arm and the second tuning fork arm on the outside of the first tuning fork arm and the second tuning fork arm. The first frame portion is connected to the second frame portion via the third frame portion and the fourth frame portion, and the base portion is connected via the connection portion. Connected to the third frame portion, the lengths of the outer side surfaces of the first frame portion to the fourth frame portion are given by a, b, c, d, respectively, and the sum is defined by the first length dimension Lo, and Lo = a + b + c + d, the lengths of the inner side surfaces of the first frame portion to the fourth frame portion are given by A, B, C, D, respectively, and the sum is defined by the second length dimension Li, and , Li = A + B + C + D, the first length dimension Lo is in the range of 2.4 mm to 5 mm, and the second length dimension Li is a piezoelectric vibrator in the range of 1.6 mm to 4.2 mm. is there.
According to a second aspect of the piezoelectric vibrator of the present invention, in the first aspect, the fourth frame portion extends in a different direction from the first tuning fork arm and the second tuning fork arm, and the width F4 of the fourth frame portion is the first. The piezoelectric vibrator is different from the interval W3 between the second vibration part of the first tuning fork arm and the second vibration part of the second tuning fork arm.

A first aspect of the piezoelectric unit of the present invention is a piezoelectric unit comprising the piezoelectric vibrator described in the first aspect, a case, and a lid, and the dimension of the maximum side of the piezoelectric unit is Each of the case and the lid includes at least a first fixing portion to a fourth fixing portion, and the first frame portion is the first fixing portion of the case and the first of the lid. The first frame portion is fixed to the first fixing portion of the case and the first fixing portion of the lid so that the second frame portion is located between the second fixing portion of the case and the second fixing portion of the lid so as to be between the fixing portions. The second frame portion is fixed to the second fixing portion of the case and the second fixing portion of the lid, and the third frame portion is between the third fixing portion of the case and the third fixing portion of the lid so as to be in between. As described above, the third frame portion is fixed to the third fixing portion of the case and the third fixing portion of the lid, and the fourth frame portion is fixed to the fourth fixing portion and the lid of the case. To lie between the fourth fixed portion, the fourth frame portion is a piezoelectric unit which is fixed to the fourth fixed portion of the fourth fixing portion and the lid of the case.
According to a second aspect of the piezoelectric unit of the present invention, in the first aspect, the distance between the tip of the first tuning fork arm and the fourth frame portion and the distance between the tip of the second tuning fork arm and the fourth frame portion. When the intervals are defined by the interval L3, the piezoelectric unit is a piezoelectric unit in which the width F4 of the fourth frame portion is greater than or equal to the interval L3.

  A tuning fork vibrator (tuning fork piezoelectric vibrator or tuning fork crystal vibrator) formed of a piezoelectric material such as quartz includes at least a tuning fork arm, a base portion, and a frame, and these are integrally formed. Since the frame is fixed to the fixing part of the case and the lid so that the frame is sandwiched between the case and the lid, a tuning fork vibrator having a small equivalent inductance L1 is obtained, and the tuning fork vibrator, the case and the lid are An ultra-compact piezoelectric (quartz) unit constructed and provided can be realized. As a result, an ultra-small piezoelectric (quartz) unit having a maximum side dimension equal to 1.35 mm or smaller than 1.35 mm is high quality (small). It can be realized with an equivalent inductance L1). This dimension is brought about for the first time by the present invention, and its effect is extremely large.

  In addition, since the equivalent inductance L1 of the tuning fork vibrator is reduced, when the power source of the oscillator configured using this vibrator is turned on, the start time of the output signal of the oscillator is shortened. Is done.

  Furthermore, since the oscillator is configured by including an ultra-small piezoelectric (crystal) unit including a tuning fork vibrator having a small equivalent series resistance R1 and a small equivalent inductance, an amplifier, a capacitor, and a resistor, Even though it is a small oscillator, it has an excellent effect that current consumption (roughly proportional to R1) is comparable to the conventional one. In addition, the electronic device configured with the oscillator has an effect of increasing the degree of freedom in designing the electronic device and realizing an electronic device having more information.

  Hereinafter, a piezoelectric vibrator and a piezoelectric unit formed of a piezoelectric material such as quartz according to an embodiment of the present invention will be specifically described with reference to the drawings.

Tuning fork vibrator according to the first embodiment

  FIG. 1 is a plan view of a tuning fork vibrator 100 that vibrates in a bending mode according to the first embodiment of the present invention. For example, the tuning fork vibrator 100 is a tuning fork type piezoelectric vibrator formed of a piezoelectric material or a tuning fork type crystal vibrator formed of quartz. In FIG. 1, the electrode disposed on the tuning fork arm, the electrode disposed on the base portion, and the electrode disposed on the frame are omitted. The tuning fork vibrator 100 includes a base portion 30, a tuning fork arm 10 and a tuning fork arm 20 connected to the base portion 30, a connection portion 40 connected to the base portion 30, and a third portion connected to the connection portion 40. A frame part 3, a first frame part 1 and a second frame part 2 connected to the third frame part 3, and a fourth frame part 4 connected to the first frame part 1 and the second frame part 2; It is configured with. Therefore, the frame is composed of the first frame portion to the fourth frame portion.

  That is, the base portion 30 is connected to the third frame portion 3 via the connection portion 40. Specifically, the side surface of the base portion 30 is connected to the side surface of the connection portion 40, and the other side surface of the connection portion 40 is connected to the side surface of the third frame portion 3. Further, the tuning fork arm 10 includes at least a first vibrating part 11 and a second vibrating part 13. The first vibrating unit 11 includes at least a first width W and a first length L, and the second vibrating unit 13 includes a second width We larger than the first width W and a second length Le smaller than the first length L. And at least. In addition, a groove 12 is formed on the upper surface of the first vibrating section 11 and a groove 32 (not shown) is formed on the lower surface. Similarly, the tuning fork arm 20 includes at least a first vibrating portion 21 and a second vibrating portion 23. The first vibrating portion 21 includes at least a first width W and a first length L, and the second vibrating portion 23 has a second width We larger than the first width W and a second length Le smaller than the first length L. And at least. In addition, a groove 22 is formed on the upper surface of the first vibrating portion 21, and a groove 42 (not shown) is formed on the lower surface.

  More specifically, each tuning fork arm of the tuning fork arms 10 and 20 includes a first vibrating portion and a second vibrating portion, and the first vibrating portion has a first width W and a first length L. The first length L of the vibration part is larger than the second length Le of the second vibration part, the first width W of the first vibration part is smaller than the second width We of the second vibration part, The first width W of one vibration part is larger than 0.03 mm and smaller than 0.05 mm, preferably in the range of 0.035 mm to 0.048 mm. In addition, the first length L of the first vibrating portion is in the range of 0.3 mm to 0.75 mm, and preferably in the range of 0.32 mm to 0.72 mm. Furthermore, there is a relationship of We <Le or We = Le between the second width We and the second length Le of the second vibrating portion, and the second width We is in the range of 0.12 mm to 0.26 mm. In addition, the second length Le is larger than 0.15 mm and smaller than 0.5 mm, preferably in the range of 0.17 mm to 0.38 mm.

  The interval between the first frame portion 1 and the first vibration portion 21 of the tuning fork arm 20 is defined by W5 (not shown), and the second frame portion 2 and the first vibration portion 11 of the tuning fork arm 10 Is defined as W6 (not shown), with the relationship We> W5, W6, each of the distance W5 and the distance W6 being in the range of 0.02 mm to 0.18 mm, preferably Is in the range of 0.03 mm to 0.16 mm. Further, there is a relationship of W3 <W5, W6 between the interval W3, the interval W5, and the interval W6, and the interval W3 is in the range of 0.015 mm to 0.07 mm.

  In addition, if the distance between the first vibrating part 11 of the tuning fork arm 10 and the first vibrating part 21 of the tuning fork arm 20 is defined by W7 (not shown), each tuning fork arm of the tuning fork arms 10 and 20 A relationship of We = W7 or We ≠ W7 is provided between the second width We of the second vibrating section and the interval W7. That is, We> W7 or We <W7. Further, there is a relationship of W7> W5, W6 between the interval W7, the interval W5, and the interval W6. Further, the base portion 30 has a width W2 and a length L2, and the connection portion 40 has a width W1 and a length L1. In addition, the first frame part 1 has an outer dimension a, an inner dimension A and a width F1, the second frame part 2 has an outer dimension b, an inner dimension B and a width F2, and the third frame part 3 has an outer dimension. The dimension c, the inner dimension C and the width F3, and the fourth frame portion 4 have an outer dimension d, an inner dimension D and a width F4.

  Further, the distance W3 between the second vibration part 13 of the tuning fork arm 10 and the second vibration part 23 of the tuning fork arm 20 and the distance W4 between the second vibration part 13 of the tuning fork arm 10 and the second frame portion 2 are given. It is done. Similarly, the distance between the second vibrating portion 23 of the tuning fork arm 20 and the first frame portion 1 is also given by the interval W4. In addition, the distance L3 between the fourth frame portion 4 and the second vibrating portion 13 of the tuning fork arm 10 is similarly the distance L3 between the fourth frame portion 4 and the second vibrating portion 23 of the tuning fork arm 20. Given in. That is, the distance L3 is the distance between the tip of the tuning fork arm 10 and the fourth frame part 4, and is also the distance between the tip of the tuning fork arm 20 and the fourth frame part 4. Further, the spacing between the base portion 30 and the first frame portion 1 is given by W8 (not shown), and the spacing between the base portion 30 and the second frame portion 2 is W9 (not shown). Given in.

  More specifically, the interval W4 has a relationship of W4 = W3 or W4 ≠ W3, that is, a relationship of W4> W3 or W4 <W3, and the interval W4 is larger than 0.01 mm and 0.2 mm. It is smaller, preferably in the range of 0.012 mm to 0.18 mm, more preferably in the range of 0.025 mm to 0.1 mm. Further, the distance L3 has a relationship of L3 = W4 or L3 ≠ W4, that is, a relationship of L3> W4 or L3 <W4, and L3 is larger than 0.01 mm and smaller than 0.2 mm, preferably, It is in the range of 0.015 mm to 0.18 mm, more preferably in the range of 0.025 mm to 0.1 mm. In order to facilitate the etching process between the base portion and the frame and between the second vibration portion and the frame, the relationship of W3, W4 ≠ W8, W9 is provided. That is, a relationship of W3, W4 <W8, W9 or a relationship of W3, W4> W8, W9 is provided.

  Further, the length L2 of the base portion 30 is greater than or equal to the distance L3, that is, the relationship L2> L3 or L2 = L3, and the length L1 of the connecting portion 40 and the distance L3 are equal, or Have different dimensions. In other words, L1 = L3 or L1 ≠ L3, that is, L1> L3 or L1 <L3. In addition, the width We of the second vibrating portion 13 of the tuning fork arm 10 is larger than the interval between the first vibrating portion 11 and the second frame portion 2 of the tuning fork arm 10 and the second vibrating portion 23 of the tuning fork arm 20. The width We is larger than the distance between the first vibrating portion 21 of the tuning fork arm 20 and the first frame portion 1. Furthermore, a relationship of L2 <L3 may be provided.

  Further, the ratio (W / L) of the width W and the length L of the first vibrating part of each tuning fork arm 10 and tuning fork arm 20 is larger than 0.098, and preferably 0.0981 to 0.11. Is in range. Alternatively, the ratio (W / L) is less than 0.097, preferably in the range of 0.088 to 0.0968.

  Further, Le> L2 between the second length Le of the second vibrating portion, the length L2 of the base portion 30 and the width F3 of the third frame portion 3 of each tuning fork arm of the tuning fork arm 10 and the tuning fork arm 20. , F3 exists. Further, there is a relationship of W1 <W2, C between the width W1 of the connection portion 40, the width W2 of the base portion 30, and the length C of the inner side surface of the third frame portion 3. The width W1 is larger than 0.04 mm and smaller than 0.2 mm, preferably in the range of 0.045 to 0.18 mm, more preferably in the range of 0.045 mm to 0.093 mm. . further,

  In addition, there is a relationship of L2> L1 and F3 between the length L2 of the base portion 30, the length L1 of the connection portion 40, and the width F3 of the third frame portion 3, and the length L2 is .0. It is in the range of 025 mm to 0.12 mm, preferably in the range of 0.025 mm to 0.08 mm, more preferably in the range of 0.025 mm to 0.078 mm. The length L1 is larger than 0.01 mm and smaller than 0.12 mm, preferably in the range of 0.015 mm to 0.08 mm, more preferably in the range of 0.015 mm to 0.04 mm. is there.

  Further, the four widths F1, F2, F3, and F4 of the frame portion of the frame usually have a relationship of F1 = F2 = F3 = F4, but all four widths may be different widths, At least one of the widths may be different. For example, when the width F4 of the fourth frame portion 4 is different, the relationship of F4 ≠ F1 = F2 = F3 is satisfied, and when the width F3 of the third frame portion 3 is different, F3 ≠ F1 = F2 = F4. Have the relationship. As a further example, when the width F3 of the third frame portion 3 and the width F4 of the fourth frame portion 4 are different, there is a relationship of F3 ≠ F4, that is, F3> F4 or F3 <F4. In addition, the ratio (F4 / F3) is in the range of 0.45 to 1.8, preferably greater than 0.45 and less than 1, or greater than 1 and less than 1.8. . Although some examples have been described, many combinations exist and the present invention encompasses all these combinations. In particular, in order to reduce the length and reduce the size, F1 and F2 have different widths from F3 and F4. Preferably, F1 and F2 are larger than F3 and F4, that is, F1, F2> F3. , F4, and F3 and F4 have a relationship of F3> F4 or F3 = F4 or F3 <F4.

  In addition, the width F4 of the fourth frame portion 4 has a relationship of F4> L1, L3, W3, W4, and the width F1 of the first frame portion 1 and the width F2 of the second frame portion 2 are F1, F2. > L1, L2, L3, W3. In this case, there is a relationship of F1 = F2 or F1 ≠ F2. That is, there is a relationship of F1> F2 or F1 <F2. The present invention is not limited to the above relationship, and may have a relationship of F1, F2 <F3, F4. Furthermore, a relationship of F4 = L2 or F4 ≠ L2 is provided. That is, the relationship of F4> L2 or F4 <L2 is provided. In addition, in order to reduce the dimension in the direction of the tuning fork arm, there may be a relationship of F4 ≦ L1, L3, W3, W4.

  Further, when the sum of the lengths of the outer sides (outer side surfaces) of the respective frame portions from the first frame portion 1 to the fourth frame portion 4 is defined by the first length dimension Lo, it is given by Lo = a + b + c + d. The first embodiment of the present invention aims to make the maximum side length and / or the mounting area smaller than that of the conventional unit, so that the maximum side length is equal to 1.35 mm, or 1 Limited to dimensions smaller than .35 mm. This dimension is about 15.6% shorter than the maximum side length (1.6 mm) of a unit on which a conventional tuning fork type crystal resonator mounted on an electronic device or the like is mounted.

In addition, a conventional mounting area (length 1.6 mm × width 1 mm = 1.6 mm ² ) of a crystal unit equipped with a conventional tuning fork type crystal resonator is obtained, or a smaller mounting area is obtained. The first length dimension Lo is limited to a dimension equal to or smaller than 5 mm. When the dimension Lo is 5 mm, the maximum mounting area is about 1.563 mm ² , which is comparable to the conventional one. Of course, when Lo is smaller than 5 mm, it goes without saying that it is smaller than the maximum mounting area.

  Furthermore, when the sum of the lengths of the inner sides (inner side surfaces) of the respective frame portions from the first frame portion 1 to the fourth frame portion 4 is defined by the second length dimension Li, Li = A + B + C + D is given. It goes without saying that a tuning fork vibrator according to the dimension of the Li is accommodated in the Li. FIG. 3 shows the relationship between Li and the change ΔR = ΔR1 / R1 of the equivalent series resistance R1 of the tuning fork vibrator. In FIG. 3, it is standardized by R1 of the tuning fork vibrator accommodated when Li = 4.4 mm. That is, ΔR = 0 when Li = 4.4 mm. Further, when Li is 3 mm, ΔR = 2.1%, and when Li = 1.6 mm, ΔR = 4.9%. As Li becomes smaller, ΔR gradually increases. Compared with, a comparable product is obtained.

  However, when Li is smaller Li = 1.4 mm, ΔR is abruptly large as 23%, and when Li is smaller, Li = 1.2 mm, ΔR is larger as 62%. From this relationship, Li is limited to 1.6 mm. In other words, this limitation provides a product that is comparable to the conventional one.

  Further, a difference between the first length dimension Lo and the second length dimension Li is defined by a dimension difference Loi = Lo−Li. FIG. 4 shows the relationship between the dimensional difference Loi and the frequency change Δf = Δf1 / f1. In FIG. 4, it is standardized by the frequency f1 of the tuning fork vibrator housed when Loi = 3.6 mm. That is, when Loi = 3.6 mm, Δf = 0. Further, when Loi = 1.5 mm and Loi = 2.4 mm, which are equal to or larger than Loi = 0.8 mm, there is almost no frequency change Δf and the frequency is stable.

  However, when Loi = 0.65 mm, the frequency changes abruptly as Δf = 0.115%. One reason for this is the loss of vibration energy due to vibration leakage. When this frequency change is converted into vibration energy loss, it corresponds to about 0.23% leakage. Therefore, the lower limit value of Loi is limited to 0.8 mm, and the lower limit value of the first length dimension Lo is limited to 2.4 mm from the relationship between Loi = 0.8 mm and Li = 1.6 mm.

  Similarly, the upper limit value of the second length dimension Li is limited to 4.2 mm from the relationship of Loi = 0.8 mm and Lo = 5 mm. In other words, the first length dimension Lo is in the range of 2.4 mm to 5 mm, and the second length dimension Li is in the range of 1.6 mm to 4.2 mm. Loi is in the range of 0.8 mm to 3.6 mm. As a result, there is an effect that a small unit with a small mounting area provided with a tuning fork type vibrator having no frequency change can be obtained.

  As described above in detail, the present invention is not limited to the above numerically limited units, and particularly when a unit having a smaller equivalent series resistance R1 and equivalent inductance L1 is required, the size of the tuning fork vibrator Should be a little larger. That is, the upper limit value of the second length dimension Li may be changed from 4.2 mm to 4.4 mm, which is a little longer. In this case, the upper limit value of the first length Lo is limited to 5 mm to 5.2 mm from the relationship of Loi = 0.8 mm and Li = 4.4 mm.

As a result, a unit having a smaller equivalent series resistance R1 and equivalent inductance L1 can be realized. The largest footprint of the unit when it is found that there is no footprint 1.6 mm ² and inferior of 1.69 mm ^2, and the conventional units. The lower limit value of the maximum length dimension of the frame (unit) is determined from the first length dimension Lo = 2.4 mm. That is, the lower limit is 0.6 mm in consideration of impact resistance and mountability. In other words, the maximum side dimension of the unit is in the range of 0.6 mm to 1.35 mm. In order to reduce the mounting area, it is preferably in the range of 0.6 mm to 1.1 mm.

  The tuning fork vibrator according to the first embodiment has a relationship of A = B and / or C = D, but the present invention is not limited to this, and A ≠ B and / or C ≠ D. You may have the relationship. In other words, a relationship of A> B or A <B and / or C> D or C <D is provided.

  That is, by limiting the first length dimension and the second length dimension, the mounting area of the piezoelectric unit composed of the tuning fork vibrator, the case, and the lid is extremely small, the equivalent inductance L1 is small, and the small capacitance ratio is small. There is an effect that the tuning fork vibrator having the series resistance R1, excellent in aging characteristics, strong against impact, and small in energy loss due to vibration leakage can be obtained. In addition, there is a remarkable effect that the startup time of the output signal of the oscillator equipped with the tuning fork type vibrator is shortened.

  Further, the tuning fork arms 10 and 20, the base portion 30, the connection portion 40, and the first frame portion 1 to the fourth frame portion 4 of the tuning fork type vibrator 100 are integrally formed. In addition, the tuning fork vibrator 100 of the first embodiment shows two tuning fork arms, but may be three or more. That is, at least two tuning fork arms are provided.

  Although the tuning fork vibrator according to the first embodiment includes the first vibrating portion and the second vibrating portion, the present invention is not limited to this. In other words, two or more vibration parts having different widths including the third vibration part or the third vibration part and the fourth vibration part may be formed between the first vibration part and the second vibration part. In other words, the third vibration part, the fourth vibration part, the fifth vibration part, the sixth vibration part,..., And the N1 vibration part, where N1 is an integer of 7 or more. For example, when N1 = 10, the third to tenth vibration units are provided. That is, the third to N2th vibration parts are provided. However, N2 is an integer of 4 or more.

  In the first example, when at least the third vibration part is formed between the first vibration part and the second vibration part, the third width of the third vibration part is greater than the first width W of the first vibration part. It is larger and smaller than the second width We of the second vibrating part. Further, the third length of the third vibrating portion is smaller than the first length L of the first vibrating portion and smaller than the second length Le of the second vibrating portion. In addition, when the sum of the second length Le of the second vibrating portion and the third length of the third vibrating portion is defined by the length L4, the length L4 is smaller than the first length L of the first vibrating portion. . When the third vibration part is between the first vibration part and the second vibration part, the ratio (We / W) of each tuning fork arm 10 to the tuning fork arm 20 is in the range of 3.3 to 6.1. And preferably within the range of 3.3 to 5.9. In addition, the overall length Lt (= L + Le) of each tuning fork arm is in the range of 0.45 mm to 0.92 mm. Preferably, it is between 0.45 mm and 0.88 mm.

  That is, in an oscillator equipped with a tuning fork vibrator, the time for which the output signal of the oscillator takes a constant value is closely related to the vibrator shape and dimensions. Therefore, in the present invention, the time until the output signal reaches about 80% of the constant value is referred to as rise time or start-up time. When the ratio (We / W) of each tuning fork arm of the tuning fork arm 10 and the tuning fork arm 20 is 3.3 and the length Lt is 0.45 mm, the start-up time is about 0.3 seconds, and the ratio (We / W) Is 6.1 and Lt is 0.92 mm, the start-up time is about 0.7 seconds, and an effect of obtaining an oscillator with a short start-up time even if the tuning fork vibrator is made smaller than the conventional one is obtained. Is played. It goes without saying that this result is inferior to the conventional large one.

  In the second example, when at least the third vibration part and the fourth vibration part are formed between the first vibration part and the second vibration part, the third width of the third vibration part and the fourth vibration part Each width of the fourth width or at least one of the widths is larger than the first width W of the first vibrating portion and smaller than the second width We of the second vibrating portion. In addition, each of the third length of the third vibrating portion and the fourth length of the fourth vibrating portion, or at least one of the lengths is smaller than the first length L of the first vibrating portion, and the second vibration. Smaller than the second length Le of the portion.

  That is, when the third to N2th vibration parts (N2 is 4 or more) are formed between the first vibration part and the second vibration part, the third width of the third vibration part and the N2th vibration part Each width of the N2th width, or the width of at least one vibration part is larger than the first width W of the first vibration part and smaller than the second width We of the second vibration part. In addition, each of the third length of the third vibrating portion and the N2 length of the N2 vibrating portion, or the length of at least one vibrating portion is smaller than the first length L of the first vibrating portion, and , Smaller than the second length Le of the second vibrating part. When the third vibration unit and the N2 vibration unit are between the first vibration unit and the second vibration unit, the tuning fork arm 10 and the tuning fork arm are obtained in order to obtain a startup time of 0.3 to 0.7 seconds. The ratio of 20 tuning fork arms (We / W) is in the range of 3.4 to 6.3, preferably in the range of 3.4 to 6.1. In addition, the overall length Lt (= L + Le) of each tuning fork arm is in the range of 0.45 mm to 0.92 mm. Preferably, it is between 0.45 mm and 0.88 mm.

  The tuning fork vibrator according to the first embodiment is a quadrangular frame having at least four angles, that is, four frames including at least a first frame portion to a fourth frame portion, The present invention is not limited to this, and includes a frame having a pentagonal shape or more (at least five frames including at least the first frame portion to the fifth frame portion).

  Further, in the plan view of the tuning fork vibrator according to the first embodiment, the frame is a quadrangular frame, and the side surface portion of the frame is a straight line. However, the present invention is not limited to this, and the frame Even if the side portion has a concave and / or convex shape, it is included in the present invention. In this case, each of the first length dimension Lo and the second length dimension Li may be a dimension of a straight line of a side surface portion not including a concave portion and / or a convex portion in the plan view, or The dimension including the dimension of the side part of the convex part may also be used. Both are included in the present invention.

  In other words, in the plan view of the tuning fork vibrator, the end of the side portion of the frame is a straight line, but the present invention is not limited to this, and the end of the side portion of the frame is recessed. And even if it has a convex shape, it is included in the present invention. In this case, each dimension of the first length dimension Lo and the second length dimension Li may be a linear dimension at the end of the side surface portion not including the concave portion and / or the convex portion in the plan view, or The dimension including the dimension of the edge part of the side part of a recessed part and / or a convex part may be sufficient. Both are included in the present invention.

Piezoelectric unit according to the first embodiment

  FIG. 2 is a side view of the piezoelectric unit 200 according to the first embodiment of the present invention. The piezoelectric unit 200 includes the tuning fork vibrator 100, the case 60, and the lid 50 according to the first embodiment already described. The first frame portion 1 of the tuning fork vibrator 100 is located between the case 60 and the lid 50. The case 60 has an internal space 65, and the lid 50 similarly has an internal space 55. In addition, the tuning fork vibrator 100 has a thickness T1, the case 60 has a thickness T3, and the depth of the internal space 65 of the case is given by T5. On the other hand, the lid 50 has a thickness T2, and the depth of the internal space 55 of the lid is given by T4. Therefore, the thickness T of the piezoelectric unit 200 is given by T = T1 + T2 + T3. T is less than 0.6 mm, preferably greater than 0.2 mm and less than 0.5 mm, more preferably in the range of 0.25 mm to 0.38 mm.

  More specifically, each of the case 60 and the lid 50 includes a first fixing portion to a fourth fixing portion, and the first frame portion of the tuning fork vibrator 100 according to the first embodiment is the first portion of the case 60. It fixes to the 1st fixing part and the 1st fixing part of a lid | cover. That is, the first frame portion is fixed so that the first frame portion is located (sandwiched) between the first fixing portion of the case and the first fixing portion of the lid. Similarly, the second frame portion of the tuning fork vibrator 100 is fixed to the second fixing portion of the case 60 and the second fixing portion of the lid. That is, the second frame portion is fixed so that the second frame portion is located (sandwiched) between the second fixing portion of the case and the second fixing portion of the lid.

  Further, the third frame portion of the tuning fork vibrator 100 is fixed to the third fixing portion of the case 60 and the third fixing portion of the lid. That is, the third frame portion is fixed so that the third frame portion is located (sandwiched) between the third fixing portion of the case and the third fixing portion of the lid. Similarly, the fourth frame portion of the tuning fork vibrator 100 is fixed to the fourth fixing portion of the case 60 and the fourth fixing portion of the lid. That is, the fourth frame portion is fixed so that the fourth frame portion is located (sandwiched) between the fourth fixing portion of the case and the fourth fixing portion of the lid. Further, in order to obtain a tuning fork vibrator having a small equivalent series resistance R1, the vibrator is housed in a vacuum. It goes without saying that the piezoelectric unit 200 according to the first embodiment of the present invention also has the first length dimension Lo, the second length dimension Li, and the dimension difference Loi already described.

  The piezoelectric unit according to the first embodiment includes a tuning fork vibrator having at least a first frame portion to a fourth frame portion. However, the present invention is not limited to this, and a pentagon or more (at least A tuning fork vibrator having a frame in the shape of five or more frame portions including first to fifth frame portions is also included. In this case, each of the case and the lid is provided with five or more fixing portions including at least a fifth fixing portion, and the fifth frame portion of the tuning fork type piezoelectric vibrator is the fifth fixing portion of the case and the fifth fixing of the lid. Fixed to the part. That is, the fifth frame portion is fixed so that the fifth frame portion of the tuning fork type vibrator is located (sandwiched) between the fifth fixing portion of the case and the fifth fixing portion of the lid. Numerous frame parts such as the sixth frame part, the seventh frame part,... Are fixed in the same manner.

  Further, in order to realize a piezoelectric unit having a small equivalent series resistance R1 that is not affected by the acoustic effect, a small equivalent inductance L1, and a tuning fork vibrator that is resistant to impact, the case depth T5 is T5>. The relationship of T3 / 6, T5 <(3T3) / 4 is provided. Similarly, the lid depth T4 has a relationship of T4> T2 / 6 and T4 <(3T2) / 4. Preferably, the case depth T5 has a relationship of T5> T3 / 5 and T5 <T3 / 2. Similarly, the lid depth T4 has a relationship of T4> T2 / 5 and T4 <T2 / 2. Furthermore, T4 and T5 may be equal or different. That is, T4 = T5 or T4> T5 or T4 <T5.

  Specifically, the depth T5 of the case 60 and the depth T4 of the lid 50 are in the range of 0.01 mm to 0.2 mm, respectively. Preferably, it is in the range of 0.015 mm to 0.18 mm, more preferably in the range of 0.02 mm to 0.15 mm. T2 and T3 are larger than 0.06 mm and smaller than 0.27 mm, and preferably in the range of 0.08 mm to 0.16 mm. Furthermore, in order to reduce the distortion between the tuning fork vibrator of the piezoelectric unit, the case, and the lid due to the temperature change, the relationship of T1 = T2 = T3 is provided. However, the present invention is not limited to this, and a relationship of T1 ≠ T2 and T3 may be used. That is, T1> T2, T3 or T1 <T2, T3, or T2 = T3 or T2 ≠ T3. That is, T2> T3 or T2 <T3.

  Further, for example, the tuning fork type vibrator is a tuning fork type crystal vibrator made of quartz or a tuning fork type piezoelectric vibrator made of a piezoelectric material, and the case and the lid are made of a crystal material such as quartz. Yes. In addition, the tuning fork vibrator, the case, and the lid are formed using at least one method such as a chemical, physical, or mechanical etching method. A piezoelectric unit comprising a tuning fork type crystal resonator, a case and a lid is particularly called a crystal unit. Needless to say, quartz is one of piezoelectric materials.

  The present invention is not limited to the tuning fork vibrator according to the first embodiment and the piezoelectric unit according to the first embodiment, but the first length dimension Lo of the tuning fork vibrator according to the first embodiment. The second length dimension Li and the dimension difference Loi can also be applied to the dimensions of a case housing various tuning fork vibrators including the tuning fork vibrator described above. In this case, the tuning fork vibrator is fixed to the fixing portion of the case, and a lid is connected to the opening of the case to evacuate the inside of the case. That is, the tuning fork vibrator is housed in the case. More specifically, the first length dimension Lo corresponds to the outside dimension (outer side face) of the case, and the second length dimension Li corresponds to the inside dimension (inner side face) of the case. Of course, the dimension difference Loi is the difference between the first length dimension Lo on the outside (outer side face) of the case and the second length dimension Li on the inside (inner side face) of the case, and is given by the dimension difference Loi = Lo-Li. It is done.

  For example, the base portion of the tuning fork vibrator is fixed to the fixing portion of the case. At least a plurality of tuning fork arms (vibrating arms) are connected to the base portion. In other words, at least a first tuning fork arm (vibrating arm) and a second tuning fork arm (vibrating arm) are provided. In addition, all the relationships described in the first embodiment can be applied to a unit including a case for housing (fixing) a tuning fork vibrator and a lid connected to an opening of the case.

  Furthermore, in the tuning fork vibrator according to the first embodiment, the tuning fork vibrator includes the first frame portion to the fourth frame portion, but the present invention is not limited to this, and the fourth frame There is no part. That is, you may provide the 3rd frame part from the 1st frame part. In this case, the tuning fork vibrator is housed in the case. Specifically, the first frame portion is fixed to the first fixing portion in the case, and the second frame portion is fixed to the second fixing portion in the case. The lid is connected to the case so that the lid seals the opening of the case in a vacuum.

  In addition, in the tuning fork vibrator according to the first embodiment, the tuning fork vibrator includes the first frame portion to the fourth frame portion. However, the present invention is not limited to this, and at least 1 Individual frames (frames) may be provided. In this case, at least one frame is fixed to a fixing portion in the case. The lid is connected to the case so that the lid seals the opening of the case in a vacuum.

  For example, at least one frame (for example, the fourth frame portion) may be a base portion of a tuning fork vibrator, or may be a frame connected to the base portion. In this case, at least one portion of the frame is fixed to the fixing portion of the case. Preferably, two places of the frame are fixed to the fixing portion of the case. For example, the first frame portion of the frame is fixed to the first fixing portion of the case, and the second frame portion of the frame is fixed to the second fixing portion of the case. However, the present invention is not limited to this, and three or more portions of the frame may be fixed to each fixing portion of the case.

  Although it has been described that the tuning fork type vibrator according to the first embodiment can be applied in various ways, it goes without saying that the above-described operational effects can also be achieved.

  The piezoelectric unit according to the first embodiment of the present invention is used as an oscillator. In other words, the oscillation circuit diagram constituting the oscillator includes an amplifier (CMOS inverter), a feedback resistor, a drain resistor, a plurality of capacitors, and a tuning fork vibrator. That is, the oscillation circuit includes an amplifier circuit including an amplifier and a feedback resistor, a drain resistor, a gate-side capacitor, a drain-side capacitor, a case, a lid, and a tuning fork vibrator 100 fixed to the case. And a feedback circuit configured as described above.

  Specifically, the oscillation circuit includes an amplifier circuit and a feedback circuit, the amplifier circuit includes at least an amplifier, and the feedback circuit includes at least a tuning fork vibrator and a capacitor. Further, the tuning fork type vibrator used in the oscillation circuit of the oscillator is housed in a container (unit). A so-called unit is used for the oscillation circuit. The output signal of the oscillator provided with the unit of the present invention is used as a signal for displaying time information on a display unit of an electronic device such as a portable device or a facsimile.

  Since the tuning fork vibrator and the piezoelectric unit of the present invention are provided with a small equivalent series resistance R1 and a small equivalent inductance L1 even if the tuning fork vibrator and the piezoelectric unit are miniaturized, the mobile phone particularly requires a more compact tuning fork vibrator and piezoelectric unit. It can be applied to portable devices such as telephones and electronic devices including consumer devices.

  1 is a plan view of a tuning fork vibrator that vibrates in a bending mode according to the first embodiment of the present invention. FIG.   The side view of the piezoelectric unit concerning Embodiment 1 of this invention is shown.   The relationship between 2nd length dimension Li of this invention and change (DELTA) R of equivalent series resistance R1 is shown.   The relationship between the dimension difference Loi of this invention and the change (DELTA) f of the frequency f1 is shown.

100 tuning fork type piezoelectric vibrator 10, 20 tuning fork arm 30 base portion 40 connection portion 1-4 first frame to fourth frame L length of first vibration portion of tuning fork arm L1 length of connection portion,
L2 Base part length W1 Connection part width W2 Base part widths F1 to F4 First frame to fourth frame width a First frame outer length dimension b Second frame outer length dimension c First Length 3 outside the frame 3 d Length 4 outside the fourth frame 200 Piezoelectric unit 50 Lid 60 Case A Length inside the first frame B Length inside the second frame C Length of the third frame Inner length dimension D Inner length dimension We of the fourth frame Width of the second vibration part of the tuning fork arm

Claims (4)

A tuning fork vibrator comprising a base portion, at least a first tuning fork arm and a second tuning fork arm connected to the base portion, and a frame;
Each tuning fork arm of the first tuning fork arm and the second tuning fork arm has a first vibrating portion having a first width and a first length, a second width larger than the first width, and a second length smaller than the first length. A second vibration part comprising:
A groove is formed on at least one of the upper surface and the lower surface of the first vibrating part,
The frame includes at least a first frame portion, a second frame portion, a third frame portion, and a fourth frame portion, and the first frame portion and the second frame portion are formed of a first tuning fork arm and a second tuning fork arm. The first tuning fork arm and the second tuning fork arm are formed to extend outward in the same direction, and the first frame portion is connected to the second frame portion via the third frame portion and the fourth frame portion, and the base portion The part is connected to the third frame part via the connection part,
The lengths of the outer side surfaces of the first frame portion to the fourth frame portion are given by a, b, c, d, respectively, the sum is defined by the first length dimension Lo, and given by Lo = a + b + c + d, When the lengths of the inner side surfaces of the first frame portion to the fourth frame portion are given by A, B, C and D, respectively, and the sum is defined by the second length dimension Li and given by Li = A + B + C + D ,
The piezoelectric vibrator, wherein the first length dimension Lo is in the range of 2.4 mm to 5 mm, and the second length dimension Li is in the range of 1.6 mm to 4.2 mm. In claim 1, the fourth frame portion extends in a direction different from that of the first tuning fork arm and the second tuning fork arm, and the width F4 of the fourth frame portion is such that the second vibrating portion of the first tuning fork arm and the second tuning fork arm. A piezoelectric vibrator characterized by being different from the interval W3 between the second vibrating portions. A piezoelectric unit comprising the piezoelectric vibrator according to claim 1, a case, and a lid, wherein the maximum side dimension of the piezoelectric unit is in a range of 0.6 mm to 1.35 mm. In
Each of the case and the lid includes at least a first fixing portion to a fourth fixing portion, and the first frame portion is located between the first fixing portion of the case and the first fixing portion of the lid. Is fixed to the first fixing part of the case and the first fixing part of the lid, and the second frame part is arranged between the second fixing part of the case and the second fixing part of the lid so that the second frame part is The third frame part is fixed to the second fixing part of the case and the third fixing part of the case so that the third frame part is between the third fixing part of the case and the third fixing part of the cover. The fourth frame portion is fixed to the third fixing portion of the case and the lid, and the fourth frame portion is between the fourth fixing portion of the case and the fourth fixing portion of the lid. And a piezoelectric unit fixed to the fourth fixing portion of the lid. In claim 3, when the distance between the tip portion of the first tuning fork arm and the fourth frame portion and the distance between the tip portion of the second tuning fork arm and the fourth frame portion are respectively defined by a distance L3, A piezoelectric unit characterized in that the width F4 of the frame portion is greater than or equal to the interval L3.

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