Crystal plate, crystal element using same, and intermediate wafer for crystal element

Abstract

The invention provides a crystal sheet having a novel shape suitable for manufacturing a crystal element, a crystal element using the crystal sheet, and an intermediate wafer for the crystal element. The crystal sheet is an AT-cut crystal sheet in which an X-Z'plane defined by the X-axis of the crystal and the Z '-axis of the crystal is taken as the main surface, the Y'-axis of the crystal is taken as the thickness direction, and the crystal sheet has a quadrilateral shape in plan view. Furthermore, when one of the side surfaces along both ends of the X-axis is defined as a first side surface of the X-axis, the other is defined as a second side surface of the X-axis, one of the side surfaces along both ends of the Z '-axis is defined as a first side surface of the second axis, and the other is defined as a second side surface of the second axis, the Z'-axis is defined as a second side surface of the Z '-axis. Each of the side surfaces is composed of a crystal surface derived from a crystal and an amorphous surface having an outline parallel to a normal line of the main surface.

Description

Technical Field

[0001] The present invention relates to a crystal wafer suitable for use in the manufacture of crystal elements such as crystal oscillators, crystal oscillators with temperature sensors and crystal oscillators (including crystal oscillators with temperature compensation functions), the crystal element and an intermediate wafer suitable for use in the manufacture of the crystal element. Background Art

[0002] With the miniaturization or high frequency of communication equipment, the miniaturization and high frequency of the frequency reference source of the communication equipment, that is, the crystal element, has become increasingly necessary. Therefore, it is also desired that the crystal pieces constituting the crystal element are small and thin. As a manufacturing technology for such crystal pieces, the use of photolithography and wet etching technology to manufacture AT-cut crystal pieces is widely promoted. Examples thereof are recorded, for example, in paragraphs 42 to 48 of patent document 1, FIG. 3, etc., and in paragraphs 42 to 46 of patent document 2, FIG. 3, etc.

[0003] In the crystal piece disclosed in Patent Document 1, the side surface on the +X side of the side surfaces along the X axis of the crystal consists of six crystal planes, and the side surface on the -X side consists of two crystal planes. In the crystal piece disclosed in Patent Document 2, the side surfaces along the Z axis of the crystal consist of four crystal planes respectively. In the techniques of Patent Documents 1 and 2, the side surfaces are formed by over-etching the crystal piece by more than 10% of the thickness.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2014-27505

[0007] [Patent Document 2] Japanese Patent Application Publication No. 2014-27506 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] Photolithography and wet etching are indeed effective technologies for miniaturization and high frequency of crystal pieces. However, in the case of the above technologies, the outer shape of the crystal piece may become a shape that impairs the characteristics of the crystal element due to the anisotropy of the crystal axis of the crystal.

[0010] For example, the side of the crystal piece formed by photolithography and wet etching technology, as described in Patent Documents 1 and 2, is mostly composed of an inclined surface that is inclined relative to the main surface of the crystal piece due to the crystallinity of the crystal. On the other hand, the vibration area of ​​the crystal piece is the part facing the main surface, and the part with the inclined surface does not function as a vibration area. Therefore, the more inclined surfaces the side includes, the narrower the vibration area, and therefore sometimes it is not good in improving the characteristics of the crystal element. Since the more the miniaturization of the crystal element is promoted, the smaller the shape of the crystal piece itself, the above-mentioned problem sometimes becomes serious.

[0011] The present application is made in view of the above-mentioned situation, and therefore an object of the present application is to provide a crystal piece having a novel shape suitable for use in the manufacture of a crystal element, a crystal element using the same, and an intermediate wafer for the crystal element.

[0012] [Technical means to solve the problem]

[0013] To achieve the above object, according to the first invention of the present application, i.e., the invention of a crystal piece, in which a first axis-second axis plane defined by a first axis derived from an X axis of the crystal and a second axis derived from a Z axis of the crystal is set as a main surface, and a third axis derived from a Y axis of the crystal is set as a thickness direction, in a crystal piece having a quadrilateral shape when viewed from above, characterized in that:

[0014] When one of the sides of the crystal plate intersecting the first axis is defined as the first side of the first axis and the other is defined as the second side of the first axis, and one of the sides of the crystal plate intersecting the second axis is defined as the first side of the second axis and the other is defined as the second side of the second axis,

[0015] The first side surface of the first axis, the second side surface of the first axis, the first side surface of the second axis, and the second side surface of the second axis are respectively composed of a crystal plane derived from crystal and an amorphous plane having a contour parallel to the normal line of the main surface.

[0016] In addition, the so-called non-crystalline surface in the invention includes the case of a true non-crystalline surface and the case of a non-crystalline surface when observed macroscopically but containing a tiny crystalline surface derived from crystal when observed microscopically. In any case, it is a surface having a contour that is parallel or substantially parallel to the normal line of the main surface of the crystal piece when observing the contour of the non-crystalline surface.

[0017] In addition, the non-crystalline surface mentioned in the invention preferably includes tiny bumps on its surface, such as bumps with a height difference of several nm to several 100 nm, preferably bumps of several 10 nm to several 100 nm. The reason is that it is expected to reduce unnecessary vibrations relative to the main vibration of the crystal plate.

[0018] In addition, when implementing the first invention, the crystal piece of the first invention is typically a crystal piece vibrating in a thickness shear mode, such as a so-called double-rotation crystal piece represented by an AT-cut crystal piece or a vibration piece cut by stress compensation (SC). In the case where the crystal piece is an AT-cut crystal piece, the first axis is the X-axis of the crystal, the second axis is the Z' axis of the crystal, and the third axis is the Y' axis of the crystal. Here, the so-called Z' axis and Y' axis are, as is known, angles that deviate from the Z-axis and the Y-axis of the crystal according to the cutting angle of the AT-cut crystal piece relative to the crystal raw stone.

[0019] In addition, the first invention can also be applied to a crystal piece in which the first axis derived from the X axis of the crystal and the first axis-second axis plane derived from the Y axis of the crystal are set as the main surface, and the third axis derived from the Z axis of the crystal is set as the thickness direction. For example, the first invention can also be applied to a crystal piece of a contour system such as GT cutting.

[0020] In addition, when implementing the first invention, the manufacture of the crystal piece is preferably carried out through the following steps, for example: irradiating a predetermined portion of the outer edge of the crystal piece with a laser, preferably an ultrashort pulse laser, along the predetermined portion of the outer edge of the crystal piece to form a crystallization-losing region along the thickness direction of the crystal piece at the predetermined portion of the outer edge; and immersing the crystal wafer with the crystallization-losing region formed in an etchant for wet etching, such as a hydrofluoric acid-based etchant, to remove the area of ​​the crystal wafer including the outer edge area to form the outer shape of the crystal piece.

[0021] In addition, according to the second invention of this application, namely the invention of the crystal element, it is characterized by comprising: a crystal vibrating plate including the crystal piece of the first invention and excitation electrodes arranged on the main surfaces of the front and back of the crystal piece; and a container, which houses the crystal vibrating plate.

[0022] The crystal element referred to in the second invention is typically a crystal vibrator, a crystal vibrator with a temperature sensor, or a crystal oscillator (including a crystal oscillator with a temperature compensation function).

[0023] In addition, according to the third invention of this application, namely the invention of an intermediate chip for a crystal element, it is characterized in that it includes a crystal chip including multiple crystal vibrating plates in a matrix, and the crystal vibrating plate includes the crystal chip of the first invention and excitation electrodes arranged on the front and back of the crystal chip.

[0024] [Effects of the Invention]

[0025] According to the crystal piece of the first invention of the present application, the first side surface of the first axis, the second side surface of the first axis, the first side surface of the second axis and the second side surface of the second axis are respectively composed of a crystalline surface and a non-crystalline surface derived from the crystal, and the non-crystalline surface is a non-crystalline surface having a contour parallel to the normal line of the main surface. Therefore, compared with the case where the side surface of the crystal piece is composed only of the crystalline surface of the crystal, the influence of the shape caused by the anisotropy of the crystal axis of the crystal can be reduced. Therefore, the undesirable situation that the effective vibration area of ​​the crystal piece is narrowed due to the shape caused by the anisotropy of the crystal axis of the crystal can be improved. In general, a crystal vibrator piece with a wide vibration area in a crystal vibrator piece has the advantages of easily making the electrical characteristics of the crystal vibrator piece good and increasing the design freedom of the crystal vibrator piece, so the advantages are easily obtained according to the present invention. Therefore, a crystal piece with a novel shape suitable for the manufacture of crystal elements can be provided.

[0026] Furthermore, according to the invention of the crystal element which is the second invention of the present application, a crystal element having superior characteristics than those conventionally achieved is realized.

[0027] Furthermore, according to the intermediate wafer for a crystal device according to the third invention of the present application, a crystal device having superior characteristics compared with conventional devices can be manufactured with good mass productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A to Figure 1C It is a diagram for explaining the crystal piece 10 according to the embodiment.

[0029] Figure 2A and Figure 2B It is a diagram for explaining the shape of each side surface of the crystal piece 100 of the comparative example.

[0030] Figure 3A , Figure 3B This is a diagram for explaining a crystal vibrator 20 as an embodiment of a crystal element.

[0031] Figure 4A and Figure 4B This is a diagram for explaining a crystal element 30 according to another embodiment.

[0032] Figure 5A to Figure 5D 1 and 2 are diagrams for explaining an example of a method for manufacturing the crystal wafer 10 according to the embodiment, and are diagrams for explaining an intermediate wafer 50 x for a crystal element according to the embodiment.

[0033] [Explanation of Symbols]

[0034] 10: Crystal Sheet of Implementation Method

[0035] 10a: First axis (X axis of the crystal)

[0036] 10b: Second axis (Z' axis of the crystal)

[0037] 10ca: One of the main surfaces of the crystal

[0038] 10cb: The other main surface of the crystal piece

[0039] 10cc: Normal of the main surface

[0040] 10d: The third axis (the Y' axis of the crystal)

[0041] 10aa: First side of the first axis

[0042] 10ab: Second side of the first axis

[0043] 10ba: First side of the second axis

[0044] 10bb: Second side of the second axis

[0045] 10e: Crystal face

[0046] 10f: non-crystalline surface

[0047] 10fa: Profile of amorphous surface

[0048] 10g, 10h, 10i, 10j: The four corners of the crystal

[0049] 11: Excitation electrode

[0050] 11a: Extraction electrode

[0051] 20: Crystal device (crystal oscillator) according to the embodiment

[0052] 21: Crystal vibrator

[0053] 23: Container

[0054] 23a: concave part

[0055] 23b: Embankment

[0056] 23c: Follow up with pad

[0057] 23d: External connection terminal

[0058] 25: Conductive adhesive

[0059] 27: Cover member

[0060] 30: Crystal element of other embodiments

[0061] 31: Other electronic parts (temperature sensors, oscillation circuits, etc.)

[0062] 50: AT-cut crystal wafer

[0063] L: Laser

[0064] 50a: Outer edge predetermined portion

[0065] 50b: Crystallinity disappearance region

[0066] 50x: Intermediate wafer for crystal element formation DETAILED DESCRIPTION

[0067] Hereinafter, the embodiments of the inventions of the present application will be described with reference to the accompanying drawings. In addition, the various figures used for explanation are only schematically represented to the extent that these inventions can be understood. In addition, in the various figures used for explanation, the same components are sometimes marked with the same reference numerals, and their descriptions are omitted. In addition, the shapes, materials, manufacturing method examples, etc. described in the following embodiments are merely preferred examples within the scope of the invention. Therefore, the present invention is not limited to the following embodiments.

[0068] 1-1. Crystal Sheet of Embodiment

[0069] Reference Figure 1A to Figure 1C The crystal piece 10 according to the embodiment will be described. Figure 1A to Figure 1C 1 is an explanatory diagram of a crystal plate 10 according to an embodiment, and in particular, Figure 1A This is its top view. Figure 1B It is along the crystal piece 10 Figure 1A The cross-sectional view of the PP line in the Figure 1C It is along the crystal piece 10 Figure 1A The cross-section diagram cut by line QQ in . However, Figure 1A The crystal plate 10 in the case is shown as a crystal vibrating plate including an excitation electrode 11 on the main surface 10c of the front and back. Figure 1A In the figure, reference numeral 11 a denotes an extraction electrode extending from the excitation electrode 11 to one side of the crystal piece 10 . Figure 1A to Figure 1C Each of the figures is a photograph of the crystal piece 10 according to the embodiment taken using an electron microscope (Scanning Electron Microscope (SEM)).

[0070] The crystal piece 10 of the embodiment is a crystal piece as follows: the first axis 10a derived from the X axis of the crystal and the second axis 10b derived from the Z axis of the crystal are defined as the first axis-second axis plane as the main surface 10ca and the main surface 10cb, and the third axis 10d derived from the Y axis of the crystal is set as the thickness direction and is a quadrilateral shape when viewed from above. Specifically, in this case, the crystal piece 10 of the embodiment is an AT-cut crystal piece. Therefore, the first axis 10a is the X axis of the crystal, the second axis 10b is the Z' axis of the crystal, and the third axis 10d is the Y' axis of the crystal. The Z' axis and the Y' axis are the axes that deviate from the Z axis and the Y axis of the crystal due to the cutting angle of the AT cut, respectively. In addition, in the crystal piece 10, the two facing main surfaces 10ca and 10cb are the surfaces of the region where the thickness of the crystal piece 10 is t.

[0071] Furthermore, in the crystal piece 10, when one of the side surfaces (the +X side surface in this case) of the crystal piece 10 intersecting the first axis (the X axis of the crystal in this case) is defined as the first side surface 10aa of the first axis, and the other side surface (the -X side surface in this case) is defined as the second side surface 10ab of the first axis, and one of the side surfaces of the crystal piece intersecting the second axis (the Z' axis of the crystal) is defined as the first side surface 10ba of the second axis, and the other side surface 10bb of the second axis, the first side surface 10aa of the first axis, the second side surface 10ab of the first axis, the first side surface 10ba of the second axis, and the second side surface 10bb of the second axis are respectively composed of a crystal surface 10e derived from the crystal and a non-crystallized surface 10f, and the non-crystallized surface 10f is a non-crystallized surface 10f having a contour 10fa parallel to the normal line 10cc of the main surface 10c. The side surfaces 10aa to 10bb are described in detail below.

[0072] First, refer to Figure 1B The first side surface 10aa of the first axis and the second side surface 10ab of the first axis will be described.

[0073] In this case, the first side surface 10aa of the first axis is the side surface on the +X side of the crystal among the two side surfaces intersecting the X axis of the crystal. Moreover, the first side surface 10aa of the first axis is composed of a first crystal surface 10e in contact with one of the main surfaces 10ca of the crystal plate 10, a second crystal surface 10e in contact with the other main surface 10cb of the crystal plate 10, and a non-crystalline surface 10f located between the two crystal surfaces 10e. One of the main surfaces 10ca of the crystal plate 10 is in contact with the first crystal surface 10e at an angle θ1. The other main surface 10cb of the crystal plate 10 is in contact with the second crystal surface 10e at an angle θ2.

[0074] In the case of the example, the angle θ1 is about 152 degrees, and the angle θ2 is about 149 degrees. The angles θ1 and θ2 are 150 degrees ± 5 degrees. These angles θ1 and θ2 are based on the following reference Figure 5A to Figure 5D The amount of wet etching in the manufacturing method described above is slightly changed.

[0075] Furthermore, the amorphous surface 10f included in the first side surface 10aa of the first axis is a surface of the crystal plate that is mainly concave and convex along the Y' axis, and the contour 10fa is parallel to the normal line 10cc of the main surface 10c of the crystal plate 10. The term "parallel" here also includes substantially parallel.

[0076] Furthermore, when the thickness of the portion where the main surface 10ca and the main surface 10cb of the crystal sheet 10 face each other ( Figure 1B When the thickness in the Y' direction of the non-crystalline surface 10f is defined as t, and the dimension in the Y' direction of the non-crystalline surface 10f is defined as t1, when t1 / t is large, the ratio of the side surface to the main surface being orthogonal becomes high, so it is easy to ensure the vibration area, which is preferred. t1 / t can be, for example, 50% or more, preferably 70% or more. In the case of the above embodiment, t1 / t is about 74%.

[0077] On the other hand, in this case, the second side surface 10ab of the first axis is the side surface on the -X side of the crystal among the two side surfaces intersecting the X axis of the crystal. Moreover, the second side surface 10ab of the first axis is composed of a crystal surface 10e in contact with one of the main surfaces 10ca of the crystal plate 10, and a non-crystalline surface 10f continuous from the crystal surface 10e to the other main surface 10cb side of the crystal plate 10 and in contact with the other main surface 10cb. In addition, in the example, the second side surface 10ab of the first axis is an example of a two-sided structure of one crystal surface 10e and one non-crystalline surface 10f, but there may also be a case where the second crystal surface is slightly present on the other main surface side of the non-crystalline surface 10f.

[0078] In the case of the second side surface 10ab of the first axis, the contour 10fa of the non-crystalline surface 10f in the second side surface 10ab of the first axis is also parallel (including substantially parallel) to the normal line 10cc of the main surface 10c of the crystal plate 10. Moreover, the non-crystalline surface 10f is the surface of the crystal plate that is mainly concave and convex along the Y' axis. Moreover, when the thickness of the portion where the main surface 10ca and the main surface 10cb of the crystal plate 10 face each other ( Figure 1B When the thickness in the Y' direction of the non-crystalline surface 10f is defined as t and the dimension in the Y' direction of the non-crystalline surface 10f is defined as t1, t1 / t is, for example, greater than 50%, preferably greater than 70%. In the case of the embodiment, t1 / t is approximately 90%.

[0079] According to the crystal piece 10 of the invention, since the first side surface 10aa and the second side surface 10ab of the first axis are structures including a non-crystalline surface 10f orthogonal to the main surface 10c, compared with a case where this is not the case, the length of the main surface of the crystal piece 10 along the X-axis direction of the crystal is longer, thereby achieving an effect of expanding the vibration area of ​​the crystal piece 10 along the X-axis direction of the crystal.

[0080] Next, refer to Figure 1C The first side surface 10ba of the second shaft and the second side surface 10bb of the second shaft will be described.

[0081] In this case, the first side surface 10ba of the second axis is one of the two side surfaces intersecting the Z' axis of the crystal, and in this case, the second side surface 10bb of the second axis is the other of the two side surfaces intersecting the Z' axis of the crystal. Moreover, the first side surface 10ba of the second axis is composed of a crystal surface 10e that contacts one of the main surfaces 10ca of the crystal plate 10 at an angle θ3, and a non-crystalline surface 10f that is continuous from the crystal surface 10e to the other main surface 10cb side of the crystal plate 10 and contacts the other main surface 10cb. In addition, the second side surface 10bb of the second axis is composed of a non-crystalline surface 10f and a crystal surface 10e, wherein the non-crystalline surface 10f contacts one of the main surfaces 10ca of the crystal plate 10, and the crystal surface 10e is located between the non-crystalline surface 10f and the other main surface 10cb of the crystal plate 10 and contacts the other main surface 10cb of the crystal plate 10 at an angle θ4. The non-crystalline surface 10f is a surface of the crystal plate that is mainly concave and convex along the Y' axis. Furthermore, the contour 10fa of the amorphous surface 10f of each of the first side surface 10ba and the second side surface 10bb of the second axis is parallel to the normal line 10cc of the main surface 10c of the crystal piece 10 (including a case where it is substantially parallel).

[0082] In addition, when the thickness of the portion where the main surface 10ca and the main surface 10cb of the crystal sheet 10 face each other ( Figure 1C When the thickness in the Y' direction of the non-crystalline surface 10f is defined as t, and the dimension in the Y' direction of the non-crystalline surface 10f is defined as t1, when t1 / t is large, the ratio of the side surface being orthogonal to the main surface becomes high, so it is easy to ensure the vibration area, which is preferred. t1 / t can be, for example, 50% or more, preferably 70% or more. In the case of the present embodiment, t1 / t is about 74%.

[0083] Here, the angle θ3 and the angle θ4 are based on the Figure 5A to Figure 5D The wet etching amount in the manufacturing method described in the following description slightly changes, but is in the range of about 110 to 120 degrees. In addition, the crystal planes 10e of the first side surface 10ba and the second side surface 10bb of the second axis are respectively relative to the center point R of the crystal plate 10 (refer to Figure 1C ) and become roughly point-symmetrical.

[0084] According to the crystal piece 10 of the invention, since the first side surface 10ba and the second side surface 10bb of the second axis are structures including a non-crystalline surface 10f orthogonal to the main surface 10c, the length of the main surface of the crystal piece 10 along the Z' axis of the crystal becomes longer compared to a case where this is not the case, thereby achieving an effect of expanding the vibration area of ​​the crystal piece 10 in the Z' direction.

[0085] In addition, if we focus on the four corners of the crystal plate 10 of the embodiment, the structure becomes as follows. Figure 1A As shown, when viewed from above, the four corners 10g, 10h, 10i, and 10j are right-angled corners. The so-called right angle means that the angle formed by the intersecting pieces is 90±2 degrees, preferably 90±1 degrees. If the four corners 10g, 10h, 10i, and 10j are right-angled corners when viewed from above, the effect of expanding the vibration area of ​​the crystal piece 10 can be obtained compared to a case where this is not the case, so it is preferred.

[0086] In addition, in the above-mentioned embodiment, an example of applying the present invention to an AT-cut crystal piece whose vibration region is a flat plate is described, but the present invention can also be applied to a so-called desktop type AT-cut crystal piece in which the thickness of the vibration portion as a crystal piece is thicker than other parts.

[0087] In addition, the present invention can also be applied to a crystal piece that is rotated twice, such as SC cutting, by rotating a surface perpendicular to the Y axis of the crystal by φ degrees with the Z axis of the crystal as the rotation center, and then rotating it by θ degrees with the X axis of the crystal as the rotation center. In the case, the first axis is the X' axis derived from the two rotations, the second axis is the Z' axis derived from the two rotations, and the third axis is the Y' axis derived from the two rotations.

[0088] In addition, the first invention can be applied to a vibration piece other than a vibration piece of a thickness shear mode. The first invention can be applied to a crystal piece having a contour-based vibration mode such as GT cutting.

[0089] 1-2. Crystal Sheet of Comparative Example

[0090] In order to deepen the understanding of the crystal plate of the first invention, refer to Figure 2A and Figure 2B Specifically, the comparative crystal piece 100 manufactured using conventional photolithography and wet etching techniques is described by observing four side surfaces, namely, two side surfaces intersecting the X-axis of the crystal and two side surfaces intersecting the Z'-axis of the crystal.

[0091] Figure 2A is with Figure 1B The corresponding comparative example, Figure 2B is with Figure 1C In the case of the crystal piece 100 of the comparative example, the two side surfaces ( Figure 2A ) are composed of two crystal planes 100a, 100b or two crystal planes 100c, 100d, that is, two inclined crystal planes. In addition, Figure 2A In the figure, 101 indicates bubbles generated in the embedding resin when preparing the cross-sectional observation data, and has nothing to do with the present invention. In addition, the two side surfaces ( Figure 2B ) are composed of two crystal planes 100e, 100f or two crystal planes 100g, 100h, that is, inclined crystal planes and crystal planes approximately perpendicular to the main surface, and have a structure without non-crystal planes.

[0092] In addition, each side surface in the data of the comparative example is an example, and the number of crystal planes on the side surface changes due to the amount of wet etching of the crystal wafer, and a surface state such as that of Patent Document 1 and Patent Document 2 is also produced. In any case, the side surface in the case of the comparative example is composed of a plurality of crystal planes, i.e., crystal planes inclined relative to the main surface, and is different from the structure of the present invention.

[0093] 2. Crystal Element of Embodiment

[0094] Next, refer to Figure 3A , Figure 3B The crystal element 20 according to the embodiment will be described. Figure 3A , Figure 3B 1 is an explanatory diagram of a crystal oscillator 20 as a crystal element 20 according to an embodiment, and in particular, Figure 3A This is its top view. Figure 3B The crystal element 20 is along Figure 3A The cross-section diagram of the PP line in FIG. Figure 3A In the figure, the cover member 27 included in the crystal element 20 is omitted. Figure 3A This is a diagram using an electron microscope (SEM) photograph of the crystal element 20 according to the embodiment.

[0095] A crystal oscillator 20 as a crystal device of the embodiment includes a crystal oscillating plate 21 including the crystal plate 10 of the first invention and excitation electrodes 11 provided on the main surfaces of the front and back of the crystal plate 10 ; and a container 23 housing the crystal oscillating plate 21 .

[0096] The container 23 in the case of the example described above includes a concave portion 23a having a quadrilateral shape when viewed from above for accommodating the crystal vibrating plate 21, a bank portion 23b surrounding the concave portion 23a, a bonding pad 23c for fixing and bonding the crystal vibrating plate 21, and an external connection terminal 23d provided on the outer bottom surface of the container 23 and connecting the crystal element 20 to any electronic device. The bonding pad 23c and the external connection terminal 23d are electrically connected by through-hole wiring or castellation (not shown). The container 23 can be formed of a known ceramic package.

[0097] In this case, the crystal vibrating plate 21 is a cantilever support structure. The crystal vibrating plate 21 is connected and fixed to the bonding pad 23c of the container 23 at the position of the lead-out electrode 11a by a conductive adhesive 25. The cover member 27 is bonded to the top surface of the bank 23b of the container 23 in a structure corresponding to the sealing method, so that the crystal vibrating plate 21 is sealed in the container 23.

[0098] In addition, in the above-mentioned embodiment, the example of the crystal resonator as the crystal element is shown, but Figure 4A and Figure 4B The crystal element 30 shown in the figure, in which the crystal piece 10, other electronic parts 31 such as a temperature sensor or an oscillation circuit are installed in a container 23, that is, a crystal vibrator or a crystal oscillator with a temperature sensor (including a crystal vibrator with a temperature compensation function) is also included in the electronic component of the present invention.

[0099] Although the container 23 has the recessed portion 23 a , the container 23 may be a container including a flat plate-shaped base and a cap-shaped cover member having a recessed portion for accommodating the crystal resonator plate.

[0100] Although not shown in the figure, the electronic component may also be an electronic component in which a cavity for accommodating a crystal resonator plate and a cavity for accommodating other electronic parts such as an oscillation circuit are stacked back to back and the cross section cut along the stacking direction is a so-called H-shaped structure.

[0101] 3. Example of a method for manufacturing a crystal wafer 10 and an intermediate wafer for forming a crystal element

[0102] Next, refer to Figure 5A to Figure 5D An example of a method for manufacturing the crystal piece 10 of the first invention and an embodiment of an intermediate wafer for a crystal element of the third invention will be described. Figure 5A to Figure 5D is the main part of the manufacturing process diagram for this purpose. In addition, Figure 5B , Figure 5C It is along Figure 5A Cross-sectional view of the PP line.

[0103] First, prepare an AT-cut crystal wafer 50 ( Figure 5A Then, the outer edge portion 50a of the crystal wafer 10 is irradiated with laser light, preferably ultrashort pulse laser light, to form a crystallinity-deleted region 50b ( Figure 5B ). In addition, during laser irradiation, the portion 50c (refer to Figure 5A ) is irradiated with laser. In addition, since the crystallinity-lost region 50b is formed by laser irradiation, the width W (refer to Figure 5B ) becomes narrower, thereby increasing the number of crystal pieces 10 in the crystal chip 50.

[0104] The crystal wafer having the crystal-free region 50b formed is immersed in an etchant for wet etching, such as a hydrofluoric acid-based etchant (not shown), to remove the region including the predetermined outer edge portion of the crystal wafer, thereby forming the outer shape of the crystal wafer 10 ( Figure 5C ). In the etching process, the etching of the crystallization disappearance region 50b of the crystal wafer 50 is carried out faster than that of the crystallization region. At this time, the vicinity of the surface of the crystal wafer 50 is etched in a direction intersecting the thickness direction of the crystal wafer 50 to produce a crystal surface 10e. The size of the crystal surface 10e changes depending on the length of the etching time. It can be considered that the crystallization disappearance region is etched in a state where the crystal surface disappears, and an amorphous junction surface 10f is produced, and an amorphous junction surface 10f having a contour 10fa parallel to the normal line of the main surface 10c of the crystal wafer 10 can be obtained ( Figure 5C ).

[0105] Next, the excitation electrodes 11 are formed on the front and back of each crystal piece 10 by a known film forming technology and a pattern forming technology involving a photolithography technology. Through these steps, an intermediate crystal piece 50x for forming a crystal element can be formed. That is, a crystal piece 50x including a plurality of crystal vibrating pieces 50y in a matrix can be formed. The crystal vibrating piece 50y includes the crystal piece 10 and the excitation electrodes 11 ( Figure 5D ).

Claims

1. A crystal plate, wherein a first axis-second axis plane defined by a first axis derived from an X axis of the crystal and a second axis derived from a Z axis of the crystal is set as a main surface, a third axis derived from a Y axis of the crystal is set as a thickness direction, and the crystal plate is a quadrilateral shape when viewed from above, wherein the crystal plate is characterized in that: When one of the sides of the crystal plate intersecting the first axis is defined as the first side of the first axis and the other is defined as the second side of the first axis, and one of the sides of the crystal plate intersecting the second axis is defined as the first side of the second axis and the other is defined as the second side of the second axis, The first side surface of the first axis, the second side surface of the first axis, the first side surface of the second axis, and the second side surface of the second axis are respectively composed of a crystalline surface and a non-crystalline surface derived from crystal. The non-crystalline surface is a non-crystalline surface having a contour parallel to a normal line of the main surface.

2. The crystal piece according to claim 1, characterized in that: When the thickness of the crystal piece is t and the length of the non-crystalline surface along the third axis is t1, t1 / t≧0.

5.

3. The crystal sheet according to claim 1, characterized in that: The crystal plane includes a crystal plane having one end continuous with at least one of the main surfaces of the front and back sides of the crystal piece and the other end continuous with the non-crystal plane.

4. The crystal sheet according to claim 1, characterized in that: The crystal surface includes two crystal surfaces, a first crystal surface and a second crystal surface, wherein one end of the first crystal surface is continuous with one of the main surfaces of the front and back of the crystal piece and the other end is continuous with the non-crystalline surface, and one end of the second crystal surface is continuous with the other main surface of the main surfaces of the front and back of the crystal piece and the other end is continuous with the non-crystalline surface.

5. The crystal sheet according to claim 1, characterized in that: The crystal plane is a crystal plane that is continuous with the main surface at a predetermined angle.

6. The crystal sheet according to claim 1, characterized in that: The four corners of the quadrilateral crystal piece are right-angled corners in a plan view.

7. The crystal sheet according to claim 1, characterized in that: The crystal piece is an AT-cut crystal piece. The first axis is the X axis of the crystal, The second axis is the Z' axis which deviates from the Z axis of the crystal due to the cutting angle of AT cutting. The third axis is the Y′ axis which is offset from the Y axis of the crystal due to the cutting angle of the AT cut.

8. The crystal sheet according to claim 1, characterized in that: The crystal piece is an AT-cut crystal piece. The first axis is the X axis of the crystal, The second axis is the Z' axis which deviates from the Z axis of the crystal due to the cutting angle of AT cutting. The third axis is the Y' axis which deviates from the Y axis of the crystal due to the cutting angle of AT cutting. The non-crystalline surfaces included in the side surfaces at both ends along the X-axis have rough surfaces.

9. The crystal sheet according to claim 1, characterized in that: The crystal plate is obtained by rotating the crystal plate twice: the surface perpendicular to the Y axis of the crystal is rotated by φ degrees with the Z axis of the crystal as the rotation center, and then rotating the crystal plate by θ degrees with the X axis of the crystal as the rotation center. The first axis is the X' axis resulting from the 2nd rotation, The second axis is the Z' axis resulting from the second rotation, The third axis is the Y' axis resulting from the 2nd rotation.

10. A crystal plate, wherein the first axis-second axis plane defined by the first axis derived from the X axis of the crystal and the second axis derived from the Y axis of the crystal is set as the main surface, and the third axis derived from the Z axis of the crystal is set as the thickness direction, and the crystal plate is a quadrilateral shape when viewed from above, wherein the crystal plate is characterized in that: When one of the sides of the crystal plate intersecting the first axis is defined as the first side of the first axis and the other is defined as the second side of the first axis, and one of the sides of the crystal plate intersecting the second axis is defined as the first side of the second axis and the other is defined as the second side of the second axis, The first side surface of the first axis, the second side surface of the first axis, the first side surface of the second axis, and the second side surface of the second axis are respectively composed of a crystalline surface and a non-crystalline surface derived from crystal. The non-crystalline surface is a non-crystalline surface having a contour parallel to a normal line of the main surface.

11. A crystal element, characterized in that include: A crystal resonator piece comprises the crystal piece according to any one of claims 1 to 10 and excitation electrodes provided on the main surfaces of the front and back of the crystal piece; and a container in which the crystal resonator piece is housed.

12. The crystal element according to claim 11, characterized in that The crystal element is a crystal vibrator, a crystal vibrator with a temperature sensor or a crystal oscillator.

13. An intermediate wafer for a crystal element, characterized in that A crystal wafer including a plurality of crystal vibrating pieces in a matrix, wherein the crystal vibrating piece includes the crystal wafer according to any one of claims 1 to 10 and excitation electrodes provided on the front and back of the crystal wafer.

Images