Quartz-crystal vibrating piece, crystal unit, crystal controlled oscillator, and intermediate wafer for quartz-crystal vibrating piece

Abstract

The present invention provides a crystal oscillator with a novel structure suitable for the implementation of high-frequency piezoelectric devices. The crystal oscillator (10) includes an element part, an excitation electrode (13), and a lead-out electrode (15). The element part includes: a vibrating part (11a), which is quadrilateral in plan view and vibrates in a thickness shear mode, having a thickness t1; a first thick-walled part (11b), which is rectangular in plan view, with its short side connected to one side of the vibrating part and extending along a first direction, having a thickness t2 that is thicker than the thickness t1; and a second thick-walled part (11c), which is connected to the two sides of the end of the first thick-walled part opposite to the vibrating part and extends along a second direction intersecting the first direction, having a thickness t3 that is thicker than the thickness t1 and the same as or different from the thickness t2, for connection with a container.

Description

Crystal vibrating piece, crystal oscillator, crystal oscillator, and intermediate wafer for crystal vibrating piece The present invention relates to a crystal vibrating piece, a crystal oscillator, a crystal oscillator, and an intermediate wafer for a crystal vibrating piece. In order to cope with the increase in communication volume in information communication, it is necessary to further increase the communication speed. Therefore, high frequency is also expected for piezoelectric devices that are reference signal sources for information communication. In order to achieve high frequency for crystal oscillators and crystal oscillators using piezoelectric vibrating pieces that vibrate in the thickness-shear mode, it is necessary to make the thickness of the vibrating portion thinner. However, when the thickness of the vibrating portion is made thinner, the influence of stress and the like from the supporting portion that supports the piezoelectric vibrating piece toward the vibrating portion becomes a problem. In order to avoid the above problems, for example, in Patent Document 1, as a structure of a piezoelectric device that realizes a high frequency such as 600 MHz, a piezoelectric oscillator in which a vibrating portion formed of a thin sheet and a supporting portion that is larger than the plate thickness of the vibrating portion along one side of the outer periphery of the vibrating portion are integrally formed is disclosed (Claim 1, FIG. 1, Paragraph 2, etc. of Patent Document 1). According to the technology of Patent Document 1, the thickness of the supporting portion can be set to an arbitrary thickness regardless of the oscillation frequency. Therefore, the stress of the deformation of the container can be resisted by the thickness of the supporting portion, and the change in the oscillation frequency can be prevented (Paragraph 33 of Patent Document 1). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Laid-Open No. 2001-144578 [Problems to be Solved by the Invention] However, through the research of the inventors of the present application, it is known that as a piezoelectric device for high frequency, if the development of a piezoelectric device for high frequency exceeding 400 MHz, for example, is actually promoted, further measures are required. The present invention has been completed in view of the above aspects. Therefore, the object of the present application is to provide a crystal vibrating piece including a novel structure suitable for the realization of a high-frequency crystal device, a crystal oscillator and a crystal oscillator using the crystal vibrating piece, and an intermediate wafer for forming the crystal vibrating piece. [Technical Means for Solving the Problem] In order to achieve the above object, according to the invention of the crystal vibrating piece which is the first invention of the present application, it includes: a component part, including: a vibrating part which is quadrilateral in plan view, vibrates in a thickness-shear mode, and has a thickness t1; a first thick-wall part which is rectangular in plan view, has a short side connected to one side of the vibrating part, extends along a first direction, and has a thickness t2 which is thicker than the thickness t1; and a second thick-wall part which is connected to both side surfaces of the end part on the opposite side of the vibrating part of the first thick-wall part, extends respectively along a second direction intersecting with the first direction, and has a thickness t3 which is thicker than the thickness t1 and the same as or different from the thickness t2, and is used for connecting the crystal vibrating piece with an external member; exciting electrodes which are arranged on the front and back surfaces of the vibrating part; and lead-out electrodes which start from the exciting electrodes, pass through the first thick-wall part and reach the second thick-wall part. Moreover, according to the invention of the crystal oscillator which is the second invention of the present application, it includes: the crystal vibrating piece of the first invention; and a container as the external member, which electrically connects and fixes the crystal vibrating piece through the second thick-wall part and houses the crystal vibrating piece. Moreover, according to the invention of the crystal oscillator which is the third invention of the present application, it includes: the crystal vibrating piece of the first invention; an oscillation circuit for the crystal vibrating piece; and a container as the external member, which electrically connects and fixes the crystal vibrating piece through the second thick-wall part, and houses the crystal vibrating piece and the oscillation circuit. Moreover, according to the invention of the intermediate wafer for forming a crystal vibrating piece which is the fourth invention of the present application, it is composed of a crystal wafer which includes a large number of crystal vibrating pieces of the first invention in a matrix form. When implementing the first to fourth inventions, for the crystal vibrating piece, when setting the dimension along the first direction of the vibrating part as α, the dimension along the first direction of the part of the first thick-wall part except the part connected to the second thick-wall part as β, the dimension along the first direction of the part of the second thick-wall part connected to the first thick-wall part as γ, the dimension along the second direction of the part of the first thick-wall part connected to the second thick-wall part as W, and the dimension along the second direction of the second thick-wall part as L, it will be described in detail through the embodiments described below, but preferably a part or all of these α, β, γ, W, and L are in a specified relationship with each other. Thus, compared with the case where it is not like this, the mutual interference between the vibrating part and the external member can be reduced. Moreover, when implementing the first to fourth inventions, it is preferable that the first thick-wall part includes an inclined part on the vibrating part side, and the thickness of the inclined part gradually becomes thinner toward the vibrating part. If the inclined part is included, compared with the case where it is not like this, the mutual interference between the vibrating part and the external member can be reduced. [Effects of the Invention] The crystal vibrating piece according to the present invention can realize a crystal vibrating piece having a structure in which a vibrating portion is separated from a support portion such as a container by a first thick wall portion and a second thick wall portion intersecting the first thick wall portion. Further, the connection of the crystal vibrating piece to the outside is performed through the second thick wall portion. In these respects, compared with the prior art, the influence of external stress on the vibrating portion can be reduced. Therefore, a crystal vibrating piece, a crystal oscillator, and a crystal oscillator including a novel structure suitable for realizing a high-frequency crystal device can be provided. Hereinafter, embodiments of each invention of the present application will be described with reference to the drawings. In addition, each drawing used for the description is schematically shown only to the extent that these inventions can be understood. Moreover, in each drawing used for the description, there are cases where the same constituent elements are denoted by the same reference numerals and the description thereof is omitted. Moreover, the shapes, materials, etc. described below are only preferred examples within the scope of the present invention. Therefore, each invention is not limited to the following embodiments. 1. Embodiment of the invention of the crystal vibrating piece The crystal vibrating piece 10 of the embodiment of the first invention will be described with reference to FIGS. 1(A) to 1(C). Here, FIG. 1(A) is a perspective view of the crystal vibrating piece 10, FIG. 1(B) is a side view of the crystal vibrating piece 10, and FIG. 1(C) is a top view of the crystal vibrating piece 10. The crystal vibrating piece 10 of the embodiment includes an element portion 11, an exciting electrode 13, and a lead-out electrode 15. The element portion 11 includes a vibrating portion 11a, a first thick wall portion 11b, and a second thick wall portion 11c. The vibrating portion 11a, the first thick wall portion 11b, and the second thick wall portion 11c are integrally formed, for example, formed from an AT-cut crystal wafer by photolithography. Hereinafter, the specific structure of each part will be described. The vibrating portion 11a is quadrilateral in plan view, vibrates in the thickness-shear mode, and has a thickness t1. When the component portion 11 itself is composed of an AT-cut crystal wafer, the vibrating portion 11a is also composed of an AT-cut crystal wafer. The planar shape of the vibrating portion 11a may be square or rectangular, and in the said embodiment, it is set as a square with a side length of α. The size α is determined according to the design of the vibrating portion 11a. Moreover, the thickness t1 of the vibrating portion 11a is a thickness corresponding to the oscillation frequency required for the crystal vibrating piece 10. That is, when the required oscillation frequency is, for example, 460 MHz, the thickness t1 is approximately 3.5 μm, which is quite thin. However, the said thickness is expressed as a value without considering the mass load of the exciting electrode 13. When the thickness t1 of the vibrating portion 11a is quite thin, if the size α is made too large, abnormalities such as bending of the vibrating portion 11a itself will occur. Therefore, it is advisable to determine the upper limit of the size α in consideration of this aspect. When the required oscillation frequency is, for example, 460 MHz, although not limited thereto, the upper limit of the size α of the vibrating portion 11a can be, for example, about 0.5 mm, and more preferably about 0.4 mm. The first thick wall portion 11b is rectangular in plan view, has its short side connected to one side of the vibrating portion 11a, extends along the first direction D1, and has a thickness t2 thicker than the thickness t1 of the vibrating portion 11a. Here, the dimension β along the first direction D1 of the portion of the first thick wall portion 11b except for the portion in contact with the second thick wall portion 11c is set to satisfy β > α. If β > α, compared with the case where it is not so, the vibrating portion 11a and the second thick wall portion 11c can be separated by at least the distance α, so it is preferable as it is easy to reduce the mutual interference between the second thick wall portion 11c fixed to the external member and the vibrating portion 11a. The larger the dimension β, the better because the vibrating portion 11a and the second thick wall portion 11c can be separated, and the upper limit of β is determined in consideration of the overall dimension in the first direction required for the crystal vibrating piece. Moreover, in the case of the said embodiment, one surface of the vibrating portion 11a and one surface of the first thick wall portion 11b constitute a continuous flat surface. If it is the said structure, in order to form the vibrating portion 11a, it is only necessary to etch the predetermined area of the crystal wafer (not shown) for forming the vibrating portion 11a from only one side of the crystal wafer until the remaining thickness becomes t1, so it is preferable. Moreover, in the case of the said embodiment, the first thick wall portion 11b includes an inclined portion 11ba on the vibrating portion 11a side where the thickness gradually becomes thinner toward the vibrating portion 11a. When the inclined portion 11ba is provided, compared with the case where it is not so, it is easy to reduce the mutual interference between the portion of the first thick wall portion 11b except for the inclined portion 11ba and the vibrating portion 11a. In addition, there may be a case where a step difference is provided instead of the inclined portion. Moreover, the angle formed by the inclined surface of the inclined portion 11ba and the flat surface formed by the vibrating portion 11a and the first thick-walled portion 11b is θ. In this case, the range is θ = 35 ± 3 degrees. The inclined surface with the angle θ comes from the crystal plane of the crystal generated when forming the crystal vibrating piece 10 through photolithography technology and wet etching technology, and thus contributes to forming the inclined portion with good controllability. The thickness t2 of the portion other than the inclined portion 11ba of the first thick-walled portion 11b is preferably an appropriate thickness that takes into account reducing the stress on the vibrating portion 11a and making the stability good when connecting and fixing the element portion 11 itself to the container (refer to FIG. 3). However, the thickness t2 of the first thick-walled portion 11b is not limited to this relative to the thickness t1 of the vibrating portion 11a. For example, it can be a thickness that satisfies t2 ≧ 10 · t1, and more preferably a thickness that satisfies t2 ≧ 15 · t1. The upper limit of the thickness t2 is determined by the internal height of the container in which the crystal vibrating piece 10 is installed or the economical thickness of the crystal wafer used in the manufacture of the crystal vibrating piece 10. Moreover, it is preferable that the dimension δ of the inclined portion 11ba along the first direction D1 is long enough to separate the vibrating portion 11a and the first thick-walled portion 11b. For example, it can be set as δ > t2. However, the upper limit of the dimension δ is determined in consideration of the overall dimension of the crystal vibrating piece 10 in the first direction D1, the thickness of the crystal wafer forming the crystal vibrating piece 10, or the required oscillation frequency, etc. The second thick-walled portion 11c is connected to both side surfaces of the end portion on the opposite side of the vibrating portion 11a of the first thick-walled portion 11b, and extends along the second direction D2 that intersects the first direction D1. And it has a thickness t3 that is thicker than the thickness t1 of the vibrating portion 11a and may be the same as or different from the thickness t2 of the first thick-walled portion, and is used for the connection of the crystal vibrating piece 10 and an external member such as a container (refer to FIG. 3, etc.). Here, in the case of the above-described embodiment, the direction in which the first direction D1 and the second direction D2 intersect is set as the direction in which the first direction D1 and the second direction D2 are orthogonal. In the case where the first direction D1 and the second direction D2 are in an orthogonal relationship and the crystal vibrating piece 10 is an AT-cut crystal piece, the first direction D1 can be set as the direction parallel to the X-axis of the crystal axis, and the second direction D2 can be set as the direction parallel to the Z'-axis of the crystal axis. That is, it can be set as the direction of obtaining a so-called X-length crystal vibrating piece as the crystal vibrating piece 10. However, conversely, there may also be a case where the first direction D1 is set as the direction parallel to the Z'-axis, and the second direction D2 is set as the direction parallel to the X-axis. That is, there may also be a case of obtaining a so-called Z-length crystal vibrating piece as the crystal vibrating piece 10. In addition, there may also be a case where the first direction D1 and the second direction D2 intersect in a non-orthogonal state. Moreover, the second thick wall portion 11c of the embodiment is connected to the first thick wall portion 11b with a dimension γ along the first direction D1, and extends with a dimension L along the second direction, and is quadrilateral in plan view. Here, the dimension L is preferably set to L≧0.5W with respect to the width W in the second direction of the portion of the first thick wall portion 11b that is in contact with the second thick wall portion 11c (in the embodiment, it is the same dimension as the length α of one side of the vibrating portion 11a). The reason is that: the longer L is, the more the portion of the second thick wall portion 11c connected to the external member can be separated from the vibrating portion 11a. The upper limit of the dimension L is determined, for example, in consideration of the constraints on the dimension in the direction of the second direction D2 of the crystal vibrating piece 10. In addition, in the case of the embodiment, the lengths L of the second thick wall portions 11c provided on the left and right of the first thick wall portion 11b are set to be the same, but there may also be different cases. Moreover, the dimension γ can be set to γ<β with respect to the dimension β of the first thick wall portion 11b. If γ<β, the connection width γ of the second thick wall portion 11c with respect to the first thick wall portion 11b can be specified with a specified relationship with respect to β, so it is preferred. However, if the dimension γ is small, the strength of the second thick wall portion 11c as a fixing portion cannot be ensured, so the lower limit of the dimension γ is set to be a dimension above the dimension that can ensure the strength. Moreover, the second thick wall portion 11c has a thickness t3 that is thicker than the thickness t1 of the vibrating portion 11a and is the same as or different from the thickness t2 of the first thick wall portion 11b. In addition, when the thickness of the second thick wall portion 11c is set to t3, on the premise that the thickness t3 is thicker than the thickness t1 of the vibrating portion 11a, it can be thicker or thinner than the thickness t2 of the first thick wall portion 11b. However, in the case of the embodiment, the thickness t1 of the vibrating portion 11a, the thickness t2 of the first thick wall portion 11b, and the thickness t3 of the second thick wall portion 11c are set to t1<<t2=t3. The exciting electrodes 13 are provided on the front and back surfaces of the vibrating portion 11a. The planar shape of the exciting electrodes 13 can be set to any suitable shape corresponding to the design, for example, it can be quadrilateral, circular, elliptical, etc. In the case of the embodiment, it is set to a shape with a diameter of φ that is circular in plan view. The exciting electrodes 13 are set to have a smaller planar area (φ<α) with respect to the vibrating portion 11a that is square in plan view, and are provided on the front and back surfaces of the vibrating portion 11a in a state where their center points coincide with each other and with the same size and facing each other in the front and back. However, the exciting electrodes 13 can also be in a so-called eccentric state where the center points of the exciting electrodes 13 are deviated from the center point of the vibrating portion 11a by a specified dimension. The exciting electrodes 13 can be formed of any suitable metal film. The lead-out electrode 15 extends from the excitation electrode 13 via the first thick-wall portion 11b to the second thick-wall portion 11c. Moreover, the lead-out electrode 15 is disposed in the end region in the short-side direction of the first thick-wall portion 11b along the first direction D1. In addition, the lead-out electrode 15 extends from the excitation electrode 13 to the second thick-wall portion 11c on the front and back surfaces of the vibrating portion 11a, but the lead-out electrode disposed on the surface that forms a flat surface where the vibrating portion 11a is continuous with the first thick-wall portion 11b is led around to the opposite surface of the second thick-wall portion 11c via the side surface of the second thick-wall portion 11c. The reason is to facilitate connecting and fixing the electrodes included in the container when forming the crystal oscillator (described in detail below) to the lead-out electrode 15 using a conductive adhesive or the like. The lead-out electrode 15 can be formed of any suitable metal film and is typically formed integrally with the excitation electrode 13. 2. Embodiment of the crystal vibrating piece As an embodiment of the crystal vibrating piece 10, a crystal vibrating piece having the dimensions of the main part set as the dimensions shown in the following examples was prototyped. A plurality of crystal vibrating pieces were prototyped as follows: the size α of one side of the vibrating portion 11a is 0.4 mm, the size β of the first thick-wall portion 11b other than the portion in contact with the second thick-wall portion 11c is 0.7 mm, the size γ of the second thick-wall portion 11c in contact with the first thick-wall portion 11b is 0.3 mm, the size L of the second thick-wall portion 11c in the second direction D2 is 0.2 mm, the size W of the portion of the first thick-wall portion 11b in contact with the second thick-wall portion 11c along the second direction D2 is 0.4 mm (i.e., the same as α), the size δ of the inclined portion is 0.07 mm, the thickness t1 of the vibrating portion 11a is the thickness corresponding to the oscillation frequency of 460 MHz (fundamental wave), the thicknesses t2 of the first thick-wall portion 11b and t3 of the second thick-wall portion 11c are 0.05 mm respectively, the diameter φ of the excitation electrode 13 is 0.1 mm, and the angle θ is about 35 degrees. In addition, the above-mentioned respective size values are target sizes. When studying with the target sizes, for β > α, β = α · 0.7 / 0.4 = 1.75 · α. Moreover, for γ < β, γ = β · 0.3 / 0.7 = 0.43 · β. Moreover, L = W · 0.2 / 0.4 = 0.5 · W. Moreover, for δ > t2, δ = t2 · 0.07 / 0.05 = 1.4 · t2. Since δ is 0.07 mm and t2 is 0.05 mm, the angle θ is 0.05 / 0.07 ≈ 0.714 ≈ 35.5 degrees. Hereinafter, the prototyped crystal vibrating piece will be described as the prototyped crystal vibrating piece 10x. Among the plurality of prototyped crystal vibrating pieces 10x, the sizes α, β, γ, δ, and L are within the range of 1% as the specified tolerance. A crystal oscillator is fabricated using the trial-produced crystal vibrating piece 10x, and the time-dependent change in the oscillation frequency and the time-dependent change in the drive current of the crystal oscillator are studied. Details regarding the above aspects are described in the section on the first embodiment of the crystal oscillator in the next item. Further, based on the shape and dimensions of the trial-produced crystal vibrating piece 10x, an analytical model for the finite element method is fabricated, and the stress distribution in a structure in which the model is fixed to a ceramic package at a portion corresponding to the second thick wall portion using a polyimide-based conductive adhesive is analyzed. The analysis is performed by studying the stress distribution generated in the analytical model when the temperature of the analytical model is changed from room temperature (25°C) to 125°C. FIG. 2 is a diagram showing the analyzed stress distribution. In FIG. 2, the darker the gray shade, the greater the influence of the stress in the bonding portion. In specific numerical terms, the von Mises stress at the center Q1 of the region where the first thick wall portion 11b is in contact with the second thick wall portion 11c is 4.8E+7 (to the power of 7 of 10). The von Mises stress at the center Q2 of the region from the center line P of the region other than where the first thick wall portion 11b is in contact with the second thick wall portion 11c to the second thick wall portion 11c side is 3.5E+6. The von Mises stress at the center Q3 of the region from the center line P of the region other than where the first thick wall portion 11b is in contact with the second thick wall portion 11c to the vibration portion 11a side is 2.8E+5. The von Mises stress at the center Q4 of the vibration portion 11a is 2.6E+4. It can be seen that the stress in the vibration portion 11a is three orders of magnitude smaller than the stress in the region where the first thick wall portion 11b is in contact with the second thick wall portion 11c. Further, in the first thick wall portion 11b, it can be seen that, with the vicinity of the center P in the longitudinal direction of the first thick wall portion 11b (refer to FIG. 2) as a boundary, the influence of the stress decreases as it approaches the vibration portion 11a. Accordingly, it can be known that the stress in the portion of the vibration portion 11a is smaller than that in other portions. Further, it can be considered that the stress from the support portion becomes smaller near the center of the first thick wall portion 11b in the first direction D1, that is, near β / 2≒α. Therefore, it can be known that, in terms of the above aspects, it is also preferable that β>α. 3. Embodiments of the Invention of the Crystal Oscillator Next, embodiments of the crystal oscillator, which is the second invention of this application, will be described. Fig. 3 is a perspective view for explaining the crystal oscillator 30 of the embodiment, and is a perspective view showing a part of the container 31 included in the crystal oscillator 30 cut away. The crystal oscillator 30 of the embodiment includes the crystal vibrating piece 10 of the first invention, a container 31 that electrically connects and fixes the crystal vibrating piece 10 with the second thick wall portion 11c and houses it, and a lid member 33 that seals the container 31. In the case of the above embodiment, the container 31 includes a recess 31a that houses the crystal vibrating piece 10, a wall portion 31b that surrounds the recess 31a, an adhesive pad 31c provided at a position corresponding to the second thick wall portion 11c of the crystal vibrating piece 10 on the bottom surface of the recess 31a, and an external connection terminal 31d provided on the outer bottom surface of the container 31. The adhesive pad 31c and the external connection terminal 31d are connected through a via wiring (not shown) or the like. The container 31 can be constituted by, for example, a ceramic package. The crystal vibrating piece 10 is connected and fixed to the adhesive pad 31c of the container 31 through a conductive adhesive 35 at the position of the lead electrode 15 of the second thick wall portion 11c. And, by using the lid member 33 to seal the opening of the recess 31a, the crystal oscillator 30 of the embodiment is constituted. The structure and shape of the lid member 33 can be selected according to the sealing method. In the case of the above embodiment, the lid member 33 is constituted by a flat plate-shaped member. Using the trial-produced crystal vibrating piece 10x as the crystal vibrating piece 10 assembled in the crystal oscillator 30 described with reference to Fig. 3, a plurality of crystal oscillators were trial-produced. Then, the trial-produced crystal oscillators were placed in a constant temperature bath set at a temperature of 125°C in a non-operating state, taken out from the constant temperature bath at appropriate times, and the time-dependent changes of the frequency and the drive current were measured respectively. Fig. 4(A) is a graph showing the time-dependent change of the frequency in the above test, and Fig. 4(B) is a graph showing the time-dependent change of the drive current in the above test. In both graphs, the horizontal axis is the elapsed time, and the vertical axis is the change rate of each measurement data relative to the initial value, that is, the frequency change rate (ppm) or the current change rate (%). From the two graphs, it can be seen that at the time point about 2500 hours after the start of the test, the frequency change rate is ±5 ppm and the change rate has a decreasing tendency, and it can be seen that the drive current change rate is also about 1% and has a saturation tendency. Therefore, it can be known that the trial-produced crystal oscillator exhibits practical characteristics. In addition, in the above form, a container including a recess is used as the container 31, and a flat plate-shaped lid member is used as the lid member 33, but a flat plate-shaped container can also be used as the container, and a cap-shaped lid member including a recess for housing the crystal vibrating piece can be used as the lid member. 4. Embodiments of the Invention of the Crystal Oscillator Next, embodiments of the crystal oscillator, which is the third invention of this application, will be described. Fig. 5 is a perspective view for explaining the crystal oscillator 40 of the embodiment, and is a perspective view showing a part of the container 43 included in the crystal oscillator 40 cut away. The crystal oscillator 40 of the embodiment includes the crystal vibrating piece 10 of the first invention, an oscillation circuit 41 for the crystal vibrating piece, a container 43 that electrically connects and fixes the crystal vibrating piece 10 with the second thick wall portion 11c and houses the crystal vibrating piece 10 and the oscillation circuit 41, and a lid member 33 that seals the container 43. In the case of the said embodiment, the container 43 includes a second recess 43a for housing the oscillation circuit 41 on the bottom surface of the recess 31a that houses the crystal vibrating piece 10. The other structures are set to be the same as those of the said container 31. The oscillation circuit 41 can be any suitable circuit and can include an integrated circuit having an oscillation function and a temperature compensation function, etc. In addition, in the said example, an example of a crystal oscillator with a so-called one-room structure in which the crystal vibrating piece 10 and an integrated circuit including the oscillation circuit are installed in one container is shown. However, although not shown in the drawings, the present invention can also be applied to a so-called H-type structure crystal oscillator formed by laminating a crystal chamber housing the crystal vibrating piece and an integrated circuit (Integrated Circuits, IC) chamber housing a semiconductor integrated circuit for the oscillation circuit. 5. Intermediate Wafer for Forming Crystal Vibration Elements Next, embodiments of the intermediate wafer for forming crystal vibration elements, which is the fourth invention of this application, will be described. Fig. 6 is a plan view for explaining the intermediate wafer 50 for forming crystal vibration elements of the embodiment (hereinafter simply referred to as the intermediate wafer 50) and an enlarged view of a part thereof. In addition, in Fig. 6, the crystal wafer as the intermediate wafer 50 and its relationship with the crystal axes X-axis, Y'-axis, and Z'-axis of the crystal are shown together. The intermediate wafer 50 of the embodiment is composed of a crystal wafer 50 including a plurality of crystal vibrating pieces 10 of the first invention in a matrix. In the illustrated example, the planar shape of the intermediate wafer 50 is circular, but it can also be quadrilateral. In the intermediate wafer 50, each crystal vibrating piece 10 is connected to the frame portion 51 via a break-off portion 53. Each crystal vibrating piece 10 is broken off from the intermediate wafer 50 at the break-off portion 53, singulated into the crystal vibrating piece 10, and used by being further installed in each container of a crystal oscillator or a crystal oscillator. 6. Deformation Examples of Crystal Oscillator Plates The crystal oscillator plate of the first invention can be deformed as described below. FIGS. 7(A) to 7(E) are explanatory diagrams thereof. FIGS. 7(A) to 7(D) are respectively top views of crystal oscillators of respective deformation examples, and FIG. 7(E) is a side view of the crystal oscillator of the deformation example. As shown in FIG. 7(A), the crystal oscillator plate 71 of deformation example 1 is provided with a notch extending from the left and right toward the center along the short side direction at an appropriate position in the long side direction of the first thick wall portion 11b, and the portion therebetween is set as a contraction portion 71a. In the illustrated example, the contraction portion 71a is set to one, but there may be a case where a plurality of contraction portions 71a are provided. As shown in FIG. 7(B), the crystal oscillator plate 72 of deformation example 2 is provided with a through hole 72a at an appropriate position in the long side direction of the first thick wall portion 11b. In the illustrated example, the through hole 72a is set to one, but there may be a case where a plurality of through holes 72a are provided. As shown in FIG. 7(C), the crystal oscillator plate 73 of deformation example 3 is provided with a notch extending from the top and bottom toward the center along the long side direction of the first thick wall portion at each second thick wall portion 11c, and the portion therebetween is set as a contraction portion 73a. The number of contraction portions 73a may also be plural. As shown in FIG. 7(D), the crystal oscillator plate 74 of deformation example 4 is provided with a through hole 74a at an appropriate position in the second thick wall portion 11c. The number of through holes 74a may also be plural. In deformation examples 1 to 4, a contraction portion or a through hole is provided between the connection points of the vibration portion 11a and the external member of the second thick wall portion 11c, and thus it is considered that mutual interference at the connection points of the external member of the second thick wall portion 11c can be easily reduced. The crystal oscillator plate 75 of deformation example 5 has the following structural example: inclined portions 75a and 75b or a stepped portion (not shown) are provided on both sides of the vibration portion side of the first thick wall portion 11b from the direction of the thickness t2, and the vibration portion 11a is connected to the first thick wall portion 11b in the middle of the thickness t2 of the first thick wall portion 11b. The connection position of the vibration portion 11a to the first thick wall portion 11b may be at the exact middle along the direction of the thickness t2, or may be a position biased to one side. In the case of deformation example 5, since the vibration portion 11a is connected to the first thick wall portion in a state including inclined portions etc. on both sides in the direction of the thickness t2, it is considered that the vibration portion can be easily cut off from the first thick wall portion. 10: Crystal vibrating piece of the embodiment 11: Element part 11a: Vibrating part 11b: First thick wall part 11ba, 75a, 75b: Tilt part 11c: Second thick wall part 13: Excitation electrode 15: Lead-out electrode 30: Crystal oscillator of the embodiment 31: External component (container) 31a: Recess 31b: Wall part 31c: Bonding pad 31d: External connection terminal 33: Cover member 35: Conductive adhesive 40: Crystal oscillator of the embodiment 41: Oscillation circuit (integrated circuit) 43: Container 43a: Second recess 50: Intermediate wafer for forming crystal vibrating piece 51: Frame 53: Detaching part 71 - 75: Crystal vibrating pieces of Modification 1 - Modification 5 71a, 73a: Shrinkage part 72a, 74a: Through hole D1: First direction D2: Second direction P: Center line Q1 - Q4: Center t1, t2, t3: Thickness (A) - (C) of FIG. 1 are diagrams for explaining the crystal vibrating piece 10 of the embodiment of the first invention. FIG. 2 is an analysis result obtained by the finite element method for explaining the influence of stress on the crystal vibrating piece 10 of the embodiment of the first invention. FIG. 3 is a diagram for explaining the crystal oscillator 30 of the embodiment of the second invention. (A) of FIG. 4 is a diagram for explaining the time - dependent change characteristic of the oscillation frequency of the crystal oscillator fabricated using the crystal vibrating piece 10 of the embodiment of the first invention, and (B) of FIG. 4 is a diagram for explaining the time - dependent change characteristic of the drive current of the same crystal oscillator. FIG. 5 is a diagram for explaining the crystal oscillator 40 of the embodiment of the third invention. FIG. 6 is a diagram for explaining the intermediate wafer 50 for the crystal vibrating piece of the embodiment of the fourth invention. (A) - (E) of FIG. 7 are diagrams for explaining Modification 1 - Modification 5 of the crystal vibrating piece of the first invention. 10: Crystal vibrating piece of the embodiment 11: Element part 11a: Vibrating part 11b: First thick wall part 11ba: Tilt part 11c: Second thick wall part 13: Excitation electrode 15: Lead - out electrode D1: First direction D2: Second direction t1, t2, t3: Thickness

Claims

1. A crystal oscillator, comprising: The component includes: a vibrating section, which is quadrilateral in plan view and vibrates in a thickness shear mode, having a thickness t1; a first thick-walled section, which is rectangular in plan view, with its short side connected to one side of the vibrating section and extending along a first direction, having a thickness t2 that is thicker than the thickness t1; and a second thick-walled section, which is connected to the two sides of the opposite end of the vibrating section of the first thick-walled section and extends along a second direction intersecting the first direction, having a thickness t3 that is thicker than the thickness t1 and the same as or different from the thickness t2, for connecting the crystal vibrator to an external component; an excitation electrode, disposed on the front and back sides of the vibrating section; and an output electrode, which extends from the excitation electrode through the first thick-walled section to the second thick-walled section, wherein, when the dimension of the vibrating section along the first direction is set as α, and the dimension of the portion of the first thick-walled section excluding the portion connected to the second thick-walled section along the first direction is set as β, β > α.

2. The crystal oscillator according to claim 1, wherein: When the dimension along the first direction of the portion of the second thick-walled portion that connects with the first thick-walled portion is set to γ, then γ < β.

3. The crystal oscillator according to claim 1, wherein: When the dimension along the second direction of the portion of the first thick-walled portion that connects with the second thick-walled portion is set as W, and the dimension along the second direction of the second thick-walled portion is set as L, then L≧0.5W.

4. The crystal oscillator according to claim 1, wherein: When the dimension of the portion of the second thick-walled portion that connects with the first thick-walled portion along the first direction is set to γ, γ < β, and when the dimension of the portion of the first thick-walled portion that connects with the second thick-walled portion along the second direction is set to W, and the dimension of the second thick-walled portion along the second direction is set to L, L ≧ 0.5W.

5. The crystal oscillator according to claim 1, wherein: When the dimension of the portion of the second thick-walled portion that connects to the first thick-walled portion along the first direction is set to γ, γ < β. When the dimension of the portion of the first thick-walled portion that connects to the second thick-walled portion along the second direction is set to W, and the dimension of the second thick-walled portion along the second direction is set to L, L ≧ 0.5W, and relative to t1, t2 is t2 ≧ 10・t1.

6. The crystal oscillator according to claim 1, wherein: The first thick-walled portion includes an inclined portion on the vibrating portion side, and the thickness of the inclined portion gradually decreases toward the vibrating portion.

7. The crystal oscillator according to claim 1, wherein: The first thick-walled portion includes an inclined portion on the vibrating portion side, and the thickness of the inclined portion gradually decreases toward the vibrating portion. When the dimension of the inclined portion along the first direction is defined as δ, the δ is δ > t2 relative to the thickness t2.

8. The crystal oscillator according to claim 1, wherein: The first thick-walled portion includes an inclined portion on the vibrating portion side. The thickness of the inclined portion gradually decreases toward the vibrating portion. One side of the vibrating portion and one side of the first thick-walled portion form a continuous flat surface. The angle θ formed by the inclined surface of the inclined portion and the flat surface is θ = 35 ± 3 degrees.

9. The crystal oscillator according to claim 1, wherein: When the dimension of the portion of the second thick-walled portion that connects to the first thick-walled portion along the first direction is set to γ, γ < β. When the dimension of the portion of the first thick-walled portion that connects to the second thick-walled portion along the second direction is set to W, and the dimension of the second thick-walled portion along the second direction is set to L, L ≧ 0.5W. Relative to t1, t2 is t2 ≧ 10・t1, and the first thick-walled portion includes an inclined portion on the vibrating portion side, the thickness of the inclined portion gradually thins toward the vibrating portion.

10. A crystal oscillator, comprising: A crystal oscillator according to any one of claims 1 to 9; and a container as the external component, wherein the crystal oscillator is electrically connected and fixed by the second thick-walled portion, and the crystal oscillator is housed therein.

11. A crystal oscillator, comprising: A crystal oscillator according to any one of claims 1 to 9; an oscillation circuit for the crystal oscillator; The container, which serves as the external component, electrically connects and fixes the crystal oscillator through the second thick-walled portion, and houses the crystal oscillator and the oscillation circuit.

12. An intermediate wafer for forming a crystal vibrating plate, wherein: The invention includes a crystal wafer, which comprises a plurality of crystal oscillators according to any one of claims 1 to 9 in a matrix configuration.

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