Quartz crystal vibration element and its manufacturing method

Abstract

To provide a crystal vibration element with a small temperature change in frequency and a low ESR value, and a simple manufacturing method thereof.SOLUTION: A crystal vibration element (102) includes a quartz crystal blank (110) having a pair of opposing main surfaces (112, 114), and a pair of excitation electrodes (120, 130) provided on the pair of main surfaces (112, 114) of the quartz crystal blank (110). The X-axis, Y-axis, and Z-axis are the crystal axes of the quartz crystal. The Z-axis is the rotation axis, and the X-axis and Y-axis are rotated at a rotation angle φ to define the X'-axis and Y'-axis, respectively. When the axes obtained by rotating the Y'-axis and Z-axis by a rotation angle θ are defined as the Y"-axis and Z'-axis, respectively, each of the pair of principal surfaces (112, 114) of the quartz crystal piece (110) is perpendicular to the Y"-axis. When the pair of principal surfaces (112, 114) of the quartz crystal piece (110) is viewed in plan, the angle formed by the X-axis and X'-axis is defined as ψ, and the relationships ψ=α×φ×θ and α=±0.0165 ±0.016 are satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a quartz crystal resonator element and a method for manufacturing the same. [Background technology]

[0002] Quartz crystal resonator elements are used in various electronic devices such as mobile communication terminals, communication base stations, home appliances, etc. as timing devices, sensors, oscillators, etc. Quartz crystal resonator elements include a quartz crystal blank having a pair of main surfaces and a pair of excitation electrodes provided on the pair of main surfaces of the quartz crystal blank.

[0003] For example, Patent Document 1 discloses a quartz crystal vibration element that includes a quartz crystal piece that is rotated twice and has a rectangular planar shape, where the plane perpendicular to the quartz crystal's Y axis is rotated by φ degrees around the quartz crystal's Z axis as the center of rotation, and then rotated θ degrees from that state around the quartz crystal's X axis as the center of rotation, resulting in a side along the X' axis being the first side and a side along the Z' axis being the second side.

[0004] Patent Document 2 discloses a quartz crystal vibration element including a quartz crystal blank having a pair of main surfaces parallel to an X' axis obtained by rotating the X axis, which is the crystal axis of the quartz crystal, around the Z axis, which is the crystal axis of the quartz crystal, in a range of 15 to 25 degrees, and a Z' axis obtained by rotating the Z axis, which is the crystal axis of the quartz crystal, around the X' axis, in a range of 33 to 34 degrees. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-78062 [Patent Document 2] Japanese Patent Application Publication No. 2017-192032 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the quartz crystal resonator element described in Patent Document 1, when rotating the quartz crystal by θ degrees, it is necessary to tilt the quartz crystal to measure the angle, which can make the mechanisms of the angle measurement device and quartz crystal cutting device complex. This can result in a decrease in the angular accuracy of the quartz crystal blank, an increase in the ESR value due to an increase in secondary vibrations, and an increase in the temperature change of frequency within a specified temperature range.

[0007] Furthermore, in the quartz crystal resonator element described in Patent Document 2, when the main surface of the quartz crystal blank is viewed in plan, the angle between the X-axis and the X'-axis is large, which causes a problem in that the secondary vibration increases and couples with the primary vibration, deteriorating the ESR value.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a quartz crystal resonator element having a small temperature change in frequency and a low ESR value, and a simple method for manufacturing the same. [Means for solving the problem]

[0009] A quartz crystal vibrating element according to one aspect of the present invention includes a quartz crystal blank having a pair of main surfaces facing each other, and a pair of excitation electrodes provided on the pair of main surfaces of the quartz crystal blank, wherein, with respect to X-axis, Y-axis, and Z-axis, which are crystal axes of quartz, when the X-axis and the Y-axis are rotated around the Z-axis by a rotation angle φ as the X'-axis and the Y'-axis, respectively, and the Y'-axis and the Z-axis are rotated around the X'-axis by a rotation angle θ as the Y''-axis and the Z'-axis, respectively, each of the pair of main surfaces of the quartz crystal blank is perpendicular to the Y''-axis, each of the pair of main surfaces of the quartz crystal element has a short side and a long side; When the pair of main surfaces of the crystal element are viewed in plan, the X axis and the long sides of the pair of main surfaces When the angle formed by these angles is ψ, the relationship ψ=α×φ×θ and α=±0.0165±0.016 holds.

[0010] A method for manufacturing a quartz crystal vibrating element according to another aspect of the present invention is a method for manufacturing a quartz crystal vibrating element including a quartz crystal blank having a pair of main surfaces facing each other, and a pair of excitation electrodes provided on the pair of main surfaces of the quartz crystal blank, the method including: preparing a quartz crystal having X-axis, Y-axis, and Z-axis crystal axes; specifying X'-axis and Y'-axis by rotating the X-axis and the Y-axis by a rotation angle φ around the Z-axis; cutting the quartz crystal along a plane perpendicular to the X'-axis; specifying Y"-axis and Z'-axis by rotating the Y'-axis and Z-axis by a rotation angle θ around the X'-axis; and cutting the quartz crystal along a plane perpendicular to the Y"-axis, wherein each of the pair of main surfaces of the quartz crystal blank is perpendicular to the Y"-axis, each of the pair of main surfaces of the quartz crystal element has a short side and a long side; When the pair of main surfaces of the crystal element are viewed in plan, the X axis and the long sides of the pair of main surfaces When the angle formed by these angles is ψ, the relationship ψ=α×φ×θ and α=±0.0165±0.016 holds. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a quartz crystal resonator element having a small temperature change in frequency and a low ESR value, and a simple method for manufacturing the same. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an exploded perspective view of a quartz crystal resonator according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the quartz crystal resonator shown in FIG. [Figure 3] 2 is a diagram for explaining the angle of the crystal blank shown in FIG. 1. FIG. [Figure 4] 10 is a graph illustrating the relationship between the rotation angle φ and the frequency temperature characteristics. [Figure 5] 10 is a graph illustrating the relationship between the rotation angle θ and the frequency temperature characteristics. [Figure 6] 10 is a graph illustrating the relationship between the rotation angle φ and the electromechanical coupling coefficient. [Figure 7] 1 is a flowchart illustrating a part of a method for manufacturing a quartz crystal vibrating element according to an embodiment of the present invention. [Figure 8] 1A to 1C are diagrams illustrating a method for manufacturing a quartz crystal vibrating element according to an embodiment of the present invention. [Figure 9] 1A to 1C are diagrams illustrating a method for manufacturing a quartz crystal vibrating element according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described. In the following description of the drawings, the same or similar components are denoted by the same or similar reference numerals. The drawings are illustrative, and the dimensions and shapes of each part are schematic. The technical scope of the present invention should not be interpreted as being limited to the embodiments.

[0014] <Crystal unit> First, the configuration of a quartz crystal resonator 100 according to one embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is an exploded perspective view of the quartz crystal resonator according to one embodiment of the present invention. Figure 2 is a cross-sectional view of the quartz crystal resonator shown in Figure 1.

[0015] The quartz crystal resonator 100 includes a quartz crystal resonator element 102, a lid member 140, a base member 150, and a bonding member 190. The quartz crystal resonator element 102 is disposed between the base member 150 and the lid member 140. The base member 150 and the lid member 140 form a holder for housing the quartz crystal resonator element 102. In the example shown in FIGS. 1 and 2, the base member 150 is flat, and the quartz crystal resonator element 102 is housed in a recess in the lid member 140. However, as long as at least the portion of the quartz crystal resonator element 102 to be excited is housed in the holder, the shapes of the base member 150 and the lid member 140 are not limited to those described above. For example, the base member 150 may have a recess on the side facing the lid member 140, or both the base member 150 and the lid member 140 may have recesses on their opposing sides.

[0016] The quartz crystal vibrating element 102 is an electromechanical energy conversion element capable of converting electrical energy and mechanical energy by the piezoelectric effect. The quartz crystal vibrating element 102 includes a quartz crystal blank 110, a first excitation electrode 120 and a second excitation electrode 130 that constitute a pair of excitation electrodes, a first extraction electrode 122 and a second extraction electrode 132 that constitute a pair of extraction electrodes, and a first connection electrode 124 and a second connection electrode 134 that constitute a pair of connection electrodes.

[0017] The crystal blank 110 has an upper surface 112 and a lower surface 114 that face each other. The upper surface 112 is located on the side opposite the side facing the base member 30, i.e., the side facing the top wall portion 141 of the cover member 140, which will be described later. The lower surface 114 is located on the side facing the base member 150. The upper surface 112 and the lower surface 114 are rectangular. The upper surface 112 and the lower surface 114 correspond to a pair of main surfaces of the crystal blank 110.

[0018] The primary vibration of the quartz crystal vibrating element 10 using the quartz crystal blank 110 is a thickness shear vibration mode. In the example shown in Figures 1 and 2, the top surface 112 and bottom surface 114 of the quartz crystal blank 110 are flat, but this is not limited to this. The top surface 112 and bottom surface 114 may also be mesa-shaped, inverted mesa-shaped, convex-shaped, or bevel-shaped.

[0019] The first excitation electrode 120 and the second excitation electrode 130 apply a voltage to the crystal blank 110. The first excitation electrode 120 is provided on the top surface 112 of the crystal blank 110, and the second excitation electrode 130 is provided on the bottom surface 114 of the crystal blank 110. The first excitation electrode 120 and the second excitation electrode 130 face each other across the crystal blank 110. When the top surface 112 of the crystal blank 110 is viewed from above, the first excitation electrode 120 and the second excitation electrode 130 are each rectangular and are arranged so that they overlap each other almost entirely.

[0020] Note that the planar shapes of the first excitation electrode 120 and the second excitation electrode 130 when viewing the top surface 112 of the crystal blank 110 from above are not limited to rectangular. The planar shapes of the first excitation electrode 120 and the second excitation electrode 130 may be polygonal, circular, elliptical, or a combination thereof.

[0021] The first extraction electrode 122 electrically connects the first excitation electrode 120 and the first connection electrode 124, and the second extraction electrode 132 electrically connects the second excitation electrode 130 and the second connection electrode 134. The first extraction electrode 122 is provided across the top surface 112 and the bottom surface 114 of the crystal blank 110, and the second extraction electrode 132 is provided on the bottom surface 114 of the crystal blank 110.

[0022] The first connection electrode 124 and the second connection electrode 134 electrically connect the quartz crystal vibrating element 102 to the base member 150. The first connection electrode 124 and the second connection electrode 134 are provided at both ends of one short side of the bottom surface 114 of the quartz crystal blank 110.

[0023] The first excitation electrode 120, the first extraction electrode 122, and the first connection electrode 124 are integrally formed. The same is true for the second excitation electrode 130, the second extraction electrode 132, and the second connection electrode 134. These electrodes of the quartz crystal vibrating element 102 have a multilayer structure in which, for example, a base layer and a surface layer are laminated in this order. For example, the base layer is a chromium (Cr) layer that has good adhesion to the quartz crystal blank 110, and the surface layer is a gold (Au) layer that has good chemical stability.

[0024] The base member 150 holds the crystal vibrating element 102 so as to be able to vibrate. The base member 150 includes a substrate 151, connection electrodes 160 and 162, lead electrodes 164 and 166, external electrodes 170, 172, 174 and 176, and conductive holding members 180 and 182.

[0025] The base 151 is a plate-shaped insulator having an upper surface 152 and a lower surface 154 that face each other in the thickness direction. The upper surface 152 and the lower surface 154 correspond to a pair of main surfaces of the base 151. The upper surface 152 is located on the side facing the quartz vibrating element 102 and the lid member 140, and corresponds to the mounting surface on which the quartz vibrating element 102 is mounted. From the viewpoint of suppressing thermal stress acting from the base 151 on the quartz vibrating element 102 due to thermal history such as reflow, the base 151 is preferably made of a heat-resistant material. From the same viewpoint, the base 151 may be made of a material with a thermal expansion coefficient close to that of the quartz blank 110. The base 151 is made of, for example, a ceramic substrate, a glass substrate, or a quartz substrate.

[0026] The corners of the base 151 have cutout side surfaces formed by cutting a portion of the base 151 into a cylindrical curved surface shape (also called a castellation shape). Note that the shape of the corners of the base 151 is not limited to this, and the cutout shape may be flat, or there may be no cutout and a substantially right-angled corner portion may remain.

[0027] The connection electrodes 160 and 162 are electrically connected to the quartz crystal vibrating element 102. The connection electrode 160 is electrically connected to the connection electrode 124 of the quartz crystal vibrating element 102, and the connection electrode 162 is connected to the connection electrode 134 of the quartz crystal vibrating element 102.

[0028] The extraction electrode 164 electrically connects the connection electrode 160 to the external electrode 170, and the extraction electrode 166 electrically connects the connection electrode 162 to the external electrode 172. The extraction electrodes 164 and 166 are provided on the upper surface 152 of the base 151.

[0029] The external electrodes 170 and 172 are external terminals for electrically connecting the quartz crystal vibrating element 102 to an external substrate. The external electrode 170 electrically connects the first excitation electrode 120 of the quartz crystal vibrating element 102 to the external substrate, and the external electrode 172 electrically connects the second excitation electrode 130 of the quartz crystal vibrating element 102 to the external substrate. As an example, one of the external electrodes 174 and 176 is a ground electrode that grounds the cover member 140, and the other is a dummy electrode that is not electrically connected to the quartz crystal vibrating element 102. Each of the external electrodes 170, 172, 174, and 176 is continuously provided from the cutout side surfaces provided at the four corners of the base 151 to the bottom surface 154. In the example shown in FIG. 1 , the external electrodes 170 and 172 are located at diagonal corners on the top surface 152 of the base 151, and the external electrodes 174 and 176 are located at different diagonal corners on the top surface 152 of the base 151. However, the external electrodes 170, 172, 174, and 176 are not limited to the above. Both the external electrodes 174 and 176 may be ground electrodes, or both may be dummy electrodes. The external electrodes 174 and 176 may be omitted. The external electrode 174 may be electrically connected to one of the external electrodes 170 and 172, and the external electrode 176 may be electrically connected to the other of the external electrodes 170 and 172.

[0030] The conductive holding members 180, 182 electrically connect the base member 150 and the quartz vibrating element 102 and mechanically hold the quartz vibrating element 102. The conductive holding member 180 electrically connects the first connection electrode 124 of the quartz vibrating element 102 to the connection electrode 160 of the base member 150. The conductive holding member 182 electrically connects the second connection electrode 134 of the quartz vibrating element 102 to the connection electrode 162 of the base member 150. The conductive holding members 180, 182 are a cured product of a conductive adhesive containing a thermosetting resin, a photocurable resin, or the like. The main component of the conductive holding members 180, 182 is, for example, a silicone resin. The conductive holding members 180, 182 contain conductive particles, such as metal particles containing silver (Ag).

[0031] The main component of the conductive holding members 180, 182 is not limited to silicone resin, but may be, for example, epoxy resin or acrylic resin. Furthermore, the conductive particles contained in the conductive holding members 180, 182 are not limited to silver particles, but may be formed from other metals, conductive ceramics, conductive organic materials, etc. The conductive holding members 180, 182 may also contain a conductive polymer.

[0032] The lid member 140 has a top wall 141 and a side wall 142 extending from the outer edge of the top wall 141 toward the base member 150. The top wall 141 faces the base member 150 across the quartz crystal resonator element 102, and the side wall 142 surrounds the quartz crystal resonator element 102 at a distance. The lid member 140 is preferably made of a conductive material, more preferably a highly airtight metal material. The conductive material of the lid member 140 provides the lid member 140 with an electromagnetic shielding function that reduces the transmission of electromagnetic waves into and out of the internal space 101. To suppress thermal stress, the lid member 140 is preferably made of a material with a thermal expansion coefficient similar to that of the base member 150, such as an Fe-Ni-Co alloy whose thermal expansion coefficient at room temperature matches that of glass or ceramic over a wide temperature range. The lid member 140 is electrically connected to at least one of the external electrodes 174 and 176 via a grounding member (not shown).

[0033] The bonding member 190 bonds the base member 150 and the lid member 140 together, sealing the internal space 101 housing the crystal vibrating element 102. The bonding member 190 is provided in a frame shape around the entire outer periphery of the base member 150 and is sandwiched between the tip of the side wall portion 142 of the lid member 140 and the top surface 152 of the base member 150. The bonding member 190 is made of an insulating material. The bonding member 190 is formed using an organic adhesive containing, for example, an epoxy-based, vinyl-based, acrylic-based, urethane-based, or silicone-based resin. The material of the bonding member 190 is not limited to organic adhesives, and may be inorganic adhesives such as silicon-based adhesives containing water glass or calcium-based adhesives containing cement. The material of the bonding member 190 may also be low-melting-point glass (e.g., lead borate-based or tin phosphate-based).

[0034] Next, the configuration of crystal blank 110 will be described in more detail with reference to Figures 3 to 6. Figure 3 is a diagram illustrating the angle of the crystal blank shown in Figure 1. Figure 4 is a graph illustrating the relationship between the rotation angle φ and the frequency temperature characteristics. Figure 5 is a graph illustrating the relationship between the rotation angle θ and the frequency temperature characteristics. Figure 6 is a graph illustrating the relationship between the rotation angle φ and the electromechanical coupling coefficient.

[0035] The principal surfaces 112, 114 of the quartz piece 110 are Z'X' planes perpendicular to the Y'' axis. The quartz piece 110 is formed by etching a quartz substrate (e.g., a quartz wafer) obtained by cutting and polishing a synthetic quartz crystal.

[0036] As shown in FIG. 3, the top surface 112 of the quartz blank 110 has a rectangular shape with long sides parallel to the X'-axis direction and short sides parallel to the Z'-axis direction. The quartz blank 110 is also plate-shaped with a thickness parallel to the Y"-axis direction. The X'-axis, Y"-axis, and Z'-axis are defined based on the crystallographic axes of the quartz. Specifically, the X'-axis and Y'-axis are axes obtained by rotating the X-axis and Y-axis, which are the crystallographic axes of the quartz, at a rotation angle φ around the Z-axis, which is the crystallographic axis of the quartz. The Y"-axis and Z'-axis are axes obtained by rotating the Y'-axis and Z-axis at a rotation angle θ around the X'-axis. The X-axis corresponds to the electrical axis (polarity axis) of the quartz, the Y-axis corresponds to the mechanical axis of the quartz, and the Z-axis corresponds to the optical axis of the quartz.

[0037] When the top surface 112 of the crystal blank 110 is viewed from above, the X axis and Long side of top surface 112 When the angle formed by these is defined as ψ, the relationships ψ=α×φ×θ and α=±0.0165±0.016 hold. By using a quartz crystal blank 110 with such an angle, it is possible to provide a quartz crystal vibrating element 102 that has good frequency-temperature characteristics and is capable of suppressing the occurrence of secondary vibrations. The angle ψ is determined by the angle between the axis obtained by projecting the X-axis onto the top surface along the Y" axis and Long side of top surface 112 This can be rephrased as the angle formed by the angle.

[0038] When viewed from the positive side of the Z axis, the counterclockwise direction is defined as positive, and the relationship 1 degree ≦ φ ≦ 14 degrees holds. As shown in Figure 4, changing the rotation angle φ shifts the frequency-temperature curve toward either the high-temperature or low-temperature side. When 1 degree ≦ φ ≦ 14 degrees, the frequency-temperature curve shifts toward the high-temperature side compared to when φ = 0 degrees. This suppresses frequency changes in the high-temperature range. Furthermore, as shown in Figure 6, changing the rotation angle φ reduces the electromechanical coupling coefficient k, peaking at φ = 0 degrees, and increases secondary vibrations. The relationship 1 degree ≦ φ ≦ 14 degrees holds, suppressing the reduction in the electromechanical coupling coefficient k and suppressing secondary vibrations, thereby keeping the ESR value low.

[0039] When viewed from the positive side of the X' axis, the counterclockwise direction is defined as positive, and the relationship 30 degrees≦θ≦40 degrees is preferably established. As shown in FIG. 5, when the rotation angle θ is changed, the frequency-temperature curve rotates around the inflection point. When 30 degrees≦θ≦40 degrees, the frequency-temperature curve rotates clockwise compared to when θ=0 degrees. This suppresses frequency changes in the low and high temperature ranges. By setting 1 degree≦φ≦14 degrees and 30 degrees≦θ≦40 degrees, the guaranteed temperature range of the quartz crystal vibrating element 102 can be expanded toward the high temperature side.

[0040] <Manufacturing method> Next, a method for manufacturing a quartz crystal vibrating element 102 according to one embodiment of the present invention will be described with reference to Fig. 7 to Fig. 9. Fig. 7 is a flowchart showing a part of a method for manufacturing a quartz crystal vibrating element according to one embodiment of the present invention. Fig. 8 and Fig. 9 are diagrams for explaining a method for manufacturing a quartz crystal vibrating element according to one embodiment of the present invention.

[0041] First, a quartz crystal XT0 is prepared (S110). The quartz crystal XT0 is cut on the XY plane perpendicular to the Z axis.

[0042] Next, the X'-axis and Y'-axis of the quartz crystal XT0 are identified (S120), and the quartz crystal XT0 is cut in the ZX'-plane and Y'Z-plane (S130). The quartz crystal XT0 is placed on the rotary stage so that one XY-plane abuts against the mounting surface of the rotary stage and the other XY-plane faces upward. Next, the other XY-plane is used as the measurement plane, and the crystal orientation of the quartz crystal XT0 is measured using an X-ray orientation measurement device while the rotary stage is rotated in the in-plane direction of the mounting surface. This identifies the X'-axis and Y'-axis directions of the quartz crystal XT0. Next, the quartz crystal XT0 on the rotary stage is cut along the X'-axis and Y'-axis using a blade of a quartz crystal cutting device installed perpendicular to the mounting surface of the rotary stage. This results in the quartz crystal XT1 being cut out from the quartz crystal XT0, as shown in Figure 8. In step S130, it is sufficient that the quartz crystal XT0 is cut in the Y'Z plane, which will be the measurement plane of the X-ray orientation measurement device in the subsequent step S140; it is not necessary to cut the quartz crystal XT0 in the ZX' plane. For details of such crystal orientation measurement and cutting processing of quartz crystal, please refer to the paper "MAKING DOUBLY ROTATED QUARTZ PLATES" (added to IEEE Xplore on December 5, 2005) by W.L. Bond and J.A. Kusters, presented at the 31st Annual Symposium on Frequency Control (June 1-3, 1977), and the numerical values ​​of the rotation angles in this embodiment were measured in accordance with this paper.

[0043] Next, the Y" and Z' axes of the crystal XT1 are identified (S140), and the crystal XT1 is cut in the X'Y" and Z'X' planes (S150). As in step S120, the Y'Z plane of the crystal XT1 placed on the mounting surface of the rotary stage is used as the measurement plane of the X-ray direction measurement device, and the Y" and Z' axis directions of the crystal XT1 are identified. Also, as in step S130, the crystal XT1 on the rotary stage is cut along the Y" and Z' axes. At this time, multiple substrate-shaped crystals XT2 are cut out from the crystal XT1.

[0044] After this, multiple crystal blanks 110 are formed within a single crystal XT2 by, for example, etching, and excitation electrodes and the like are provided to form an aggregate substrate of crystal resonator elements 102. At this time, the etching may be used to impart shapes such as mesa, inverted mesa, convex, or bevel to each of the multiple crystal blanks 110. Finally, the aggregate substrate is separated into individual crystal resonator elements 102. Note that the method for forming the multiple crystal blanks 110 within the crystal XT2 is not limited to etching, and may also be mechanical cutting or other processes. Furthermore, the method for imparting shapes to each of the multiple crystal blanks 110 is not limited to etching, and may also be chemical mechanical polishing or other processes. The process for imparting shapes to each of the multiple crystal blanks 110 may be performed before or after the excitation electrodes and the like are provided.

[0045] As described above, in the quartz crystal vibrating element 102 according to one embodiment of the present invention, the axes obtained by rotating the X-axis and Y-axis around the Z-axis by a rotation angle φ are defined as the X'-axis and Y'-axis, respectively, and the axes obtained by rotating the Y'-axis and Z-axis around the X'-axis by a rotation angle θ are defined as the Y''-axis and Z'-axis, respectively, when the pair of main surfaces 112, 114 of the quartz crystal blank 110 are viewed in plan view, Long sides of the pair of principal surfaces 112, 114 When the angle formed by these angles is ψ, the relationship ψ=α×φ×θ and α=±0.0165±0.016 holds.

[0046] This provides the crystal vibrating element 102 with a small temperature change in frequency and a low ESR value.

[0047] In one aspect of the above, when the counterclockwise direction is defined as positive as viewed from the positive side of the Z axis, the relationship 1 degree≦φ≦14 degrees holds.

[0048] This makes it possible to suppress changes in frequency in the high temperature range, and also to suppress a decrease in the electromechanical coupling coefficient k, thereby suppressing secondary vibrations and keeping the ESR value low.

[0049] In one aspect of the above, when the counterclockwise direction is defined as positive as viewed from the positive side of the X' axis, the relationship 30 degrees≦θ≦40 degrees holds.

[0050] This makes it possible to suppress changes in frequency in the low temperature range and the high temperature range.

[0051] In one embodiment of the above, each of the pair of main surfaces 112, 114 of the crystal blank 110 is rectangular with sides parallel to the X'-axis and Z'-axis.

[0052] This allows the internal space 101 of the crystal unit 100 to be efficiently utilized, maximizing the size of the crystal blank 110. This allows the ESR value to be kept low.

[0053] In addition, a manufacturing method of a quartz crystal vibrating element 102 according to another embodiment of the present invention includes identifying the Y'' axis and Z' axis of the quartz crystal XT1, cutting the quartz crystal XT1 in the Z'Y' plane and the Z'X' plane, identifying the Y'' axis and Z' axis of the quartz crystal XT1, and cutting the quartz crystal XT1 in the Z'Y' plane and the Z'X' plane.

[0054] This allows for the provision of a quartz crystal vibrating element 102 that has excellent frequency-temperature characteristics and is capable of suppressing the occurrence of secondary vibrations. Furthermore, there is no need to tilt the quartz crystal during measurement using a crystal orientation measurement device or during processing using a quartz crystal cutting device. Therefore, compared to manufacturing methods that involve tilting the quartz crystal to measure the crystal orientation or cut the quartz crystal, the quartz crystal vibrating element 102 can be manufactured more easily, and the angle error of the quartz crystal blank 110 can be reduced.

[0055] In the quartz crystal vibrating element according to one embodiment of the present invention, the internal space 101 may be sealed with metal. That is, the base member and the lid member may be joined by a joining member made of a metal material. In this case, the connection electrodes of the base member are spaced apart from the sealing member, and the connection electrodes of the base member and the external electrodes are electrically connected by, for example, through electrodes that penetrate the base member.

[0056] Some or all of the embodiments of the present invention will be described below, but the present invention is not limited to the following descriptions.

[0057] According to one aspect of the present invention, a crystal blank having a pair of opposing main surfaces and a pair of excitation electrodes provided on the pair of main surfaces of the crystal blank is provided, and when, with respect to the X-axis, Y-axis, and Z-axis, which are the crystal axes of the crystal, the X-axis and the Y-axis rotated by a rotation angle φ around the Z-axis as the rotation axis are defined as the X'-axis and the Y'-axis, respectively, and the Y'-axis and the Z-axis rotated by a rotation angle θ around the X'-axis are defined as the Y''-axis and the Z'-axis, respectively, each of the pair of main surfaces of the crystal blank is perpendicular to the Y''-axis, Each of the pair of main surfaces of the crystal blank has a short side and a long side, When the pair of main surfaces of the crystal blank is viewed in plan, the X axis and Long sides of a pair of main faces When the angle formed by the angle θ and the angle φ is ψ, the relationship ψ=α×φ×θ and α=±0.0165±0.016 is satisfied.

[0058] In one aspect of the above-described quartz crystal vibrating element, when viewed from the positive side of the Z axis, the relationship 1 degree≦φ≦14 degrees holds true, where the counterclockwise direction is positive.

[0059] In one aspect of the above-described quartz crystal vibrating element, when viewed from the positive side of the X' axis, the relationship 30 degrees≦θ≦40 degrees holds true, where θ is defined as being positive in the counterclockwise direction.

[0060] In one aspect of the quartz crystal vibrating element, each of the pair of main surfaces of the quartz crystal blank is rectangular with sides parallel to the X'-axis and Z'-axis.

[0061] In one aspect of the quartz crystal vibrating element, the main vibration is a thickness-shear vibration mode.

[0062] A quartz crystal unit is provided, comprising a quartz crystal vibration element according to any of the above aspects, a base member, and a lid member joined to the base member, with the quartz crystal vibration element being disposed in the internal space between the base member and the lid member.

[0063] According to another aspect of the present invention, there is provided a method for manufacturing a quartz crystal resonator element including a quartz crystal blank having a pair of opposing main surfaces and a pair of excitation electrodes provided on the pair of main surfaces of the quartz crystal blank, the method including: preparing a quartz crystal having X-axis, Y-axis, and Z-axis crystal axes; specifying X'-axis and Y'-axis by rotating the X-axis and Y-axis by a rotation angle φ around the Z-axis; cutting the quartz crystal along a plane perpendicular to the X'-axis; specifying Y"-axis and Z'-axis by rotating the Y'-axis and Z-axis by a rotation angle θ around the X'-axis; and cutting the quartz crystal along a plane perpendicular to the Y"-axis, wherein each of the pair of main surfaces of the quartz crystal blank is perpendicular to the Y"-axis, Each of the pair of main surfaces of the crystal blank has a short side and a long side, When the pair of main surfaces of the crystal blank is viewed in plan, the X axis and Long sides of a pair of main faces When the angle formed by these is ψ, the relationships ψ=α×φ×θ and α=±0.0165±0.016 are satisfied.

[0064] In one aspect of the manufacturing method of the above-described quartz crystal vibrating element, when viewed from the positive side of the Z axis, the relationship 1 degree≦φ≦14 degrees holds.

[0065] In one aspect of the manufacturing method of the above-described quartz crystal vibrating element, when viewed from the positive side of the X' axis, the relationship 30 degrees≦θ≦40 degrees holds true.

[0066] One aspect of the method for manufacturing the above-mentioned quartz crystal vibrating element further includes cutting the quartz crystal along a plane perpendicular to the Z' axis, and each of the pair of main surfaces of the quartz crystal piece is rectangular with sides parallel to the X' axis and the Z' axis.

[0067] As described above, according to one aspect of the present invention, it is possible to provide a quartz crystal resonator element having a small temperature change in frequency and a low ESR value, and a simple method for manufacturing the same.

[0068] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. The present invention may be modified or improved without departing from its spirit, and equivalents are also encompassed within the scope of the present invention. In other words, designs resulting from appropriate design modifications made by a person skilled in the art to the embodiments and / or modifications are also encompassed within the scope of the present invention as long as they incorporate the characteristics of the present invention. For example, the elements of the embodiments and / or modifications, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. Furthermore, the embodiments and modifications are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments and / or modifications is possible. These are also encompassed within the scope of the present invention as long as they incorporate the characteristics of the present invention. [Explanation of symbols]

[0069] 100...Crystal resonator 101...Interior space 102...Crystal oscillator element 110...Crystal piece 112...Top surface 114…Bottom surface 120...1st excitation electrode 130…Second excitation electrode 122...1st extraction electrode 132…Second extraction electrode 124...First connection electrode 134...Second connection electrode 150...Base member 140...Cover member 190... Joint material φ...Rotation angle around the Z axis θ...Rotation angle around the X' axis ψ...X axis when the main surface of the crystal blank is viewed in plan Long side of the main surface of the crystal blank The angle formed by the ribs

Claims

1. a crystal element having a pair of opposing main surfaces; and a pair of excitation electrodes provided on the pair of main surfaces of the crystal element; Regarding the X-axis, Y-axis, and Z-axis, which are the crystal axes of quartz, the Z-axis is used as a rotation axis, and the X-axis and the Y-axis are rotated by a rotation angle φ to form the X'-axis and the Y'-axis, respectively. When the X'-axis is the rotation axis and the Y'-axis and the Z-axis are rotated by a rotation angle θ, the Y''-axis and the Z'-axis are respectively each of the pair of principal surfaces of the quartz crystal blank is perpendicular to the Y″ axis; When viewed from the positive side of the Z axis, the counterclockwise direction is defined as positive. 1 degree≦φ≦14 degree The relationship is established, When viewed from the positive side of the X' axis, the counterclockwise direction is defined as positive. 30 degrees≦θ≦40 degrees The relationship between Quartz crystal oscillator element.

2. Each of the pair of main surfaces of the quartz crystal element has a short side and a long side, When the pair of main surfaces of the crystal element are viewed in plan, the X-axis is inclined at an angle ψ with respect to the long sides of the pair of main surfaces. The quartz crystal resonator element according to claim 1 .

3. ψ = α × φ × θ, and α＝±０．０１６５±０．０１６ The relationship between The quartz crystal resonator element according to claim 2 .

4. Each of the pair of main surfaces of the crystal blank has sides parallel to the X'-axis and the Z'-axis. The quartz crystal resonator element according to claim 1 .

5. The main vibration is the thickness-shear mode. The quartz crystal resonator element according to claim 1 .

6. The quartz crystal resonator element according to claim 1; A base member; a cover member joined to the base member; Equipped with The crystal vibrating element is provided in the internal space between the base member and the lid member.

7. A method for manufacturing a quartz crystal vibrating element including a quartz crystal piece having a pair of main surfaces facing each other, and a pair of excitation electrodes provided on the pair of main surfaces of the quartz crystal piece, Preparing a quartz crystal having X-axis, Y-axis, and Z-axis crystal axes; Identifying X'-axis and Y'-axis obtained by rotating the X-axis and the Y-axis by a rotation angle φ around the Z-axis; cutting the crystal in a plane perpendicular to the X' axis; Identifying a Y''-axis and a Z'-axis obtained by rotating the Y'-axis and the Z-axis by a rotation angle θ around the X'-axis; cutting the quartz crystal in a plane perpendicular to the Y" axis; Including, each of the pair of principal surfaces of the quartz crystal blank is perpendicular to the Y″ axis; When viewed from the positive side of the Z axis, the counterclockwise direction is defined as positive. 1 degree≦φ≦14 degree The relationship is established, When viewed from the positive side of the X' axis, the counterclockwise direction is defined as positive. 30 degrees≦θ≦40 degrees The relationship between A method for manufacturing a quartz crystal vibrating element.

8. Each of the pair of main surfaces of the quartz crystal element has a short side and a long side, When the pair of main surfaces of the crystal element are viewed in plan, the X-axis is inclined at an angle ψ with respect to the long sides of the pair of main surfaces. The method for manufacturing a quartz crystal resonator element according to claim 7 .

9. ψ = α × φ × θ, and α＝±０．０１６５±０．０１６ The relationship between The method for manufacturing a quartz crystal resonator element according to claim 8 .

10. further comprising cutting the crystal along a plane perpendicular to the Z' axis; Each of the pair of main surfaces of the crystal blank has sides parallel to the X'-axis and the Z'-axis. The method for manufacturing a quartz crystal resonator element according to claim 7 .

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