Vibrating element and vibration device

Abstract

To provide a vibration element capable of suppressing formation of foreign substances such as a burr, a vibration device and a method for manufacturing a vibration element.SOLUTION: Vibrating arms 43, 44 of a vibration element 1 each include: a first surface 101 as a top surface; a second surface 102 as a lower surface, opposing the first surface 101 in a Z direction; a first side surface 111 and a second side surface 112 as side surfaces; and a third side surface 113 as a tip surface. At least one of the first side surface 111, the second side surface 112, and the third side surface 113 includes a first side surface part tilted with respect to the Z direction, and a second side surface part tilted toward the first surface 101 or the second surface 102 with respect to the first side surface part. A first weight 461 is arranged so that outer edges 463A, 463B, 463C of the first weight 461 are located at an inner side of innermost parts 131, 132, 133 in the first side surface part and the second side surface part, or at a same position as the innermost parts 131, 132, 133, respectively, when viewed from the Z direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vibration element, a vibration device, and a method for manufacturing a vibration element.

Background Art

[0002] Conventionally, as shown in Patent Document 1, in a vibrating piece of a crystal oscillator, a frequency adjustment metal film is formed on a first surface, a first side surface having a cross-sectional convex portion, and a second side surface, and a laser is incident from a second surface facing the first surface to remove a part of the frequency adjustment metal film, thereby adjusting the frequency. A frequency adjustment method for a crystal oscillator is known. Also, as shown in Patent Document 1, by making the angle at which the laser is incident an acute angle from the second side surface toward the first side surface, it is known that it is possible to prevent the frequency adjustment metal film to be removed from remaining as burrs in the frequency adjustment metal film on the first side surface side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the frequency adjustment method of the crystal oscillator described in Patent Document 1, since the angle at which the laser is incident is an acute angle from the second side surface toward the first side surface, when removing the frequency adjustment metal film on the second side surface side, the laser is refracted or shielded by the second side surface. For this reason, the laser is not sufficiently irradiated onto the frequency adjustment metal film on the second side surface side, and there is a risk of forming foreign matters such as burrs. If such foreign matters as burrs fall during the production process or after the product is completed, the frequency of the crystal oscillator will change.

Means for Solving the Problems

[0005] The vibrating element includes a base portion, a first surface, a second surface facing the first surface in a direction along the Z-axis, a first side surface, a second side surface facing the first side surface in a direction along the X-axis orthogonal to the Z-axis, and a third side surface located on the side opposite to the base portion, and has a vibrating arm extending from the base portion in a direction along the Y-axis orthogonal to the Z-axis and the X-axis, and a first weight disposed on the second surface. At least one of the first side surface, the second side surface, and the third side surface includes a first side surface portion inclined with respect to the direction along the Z-axis, and a second side surface portion inclined toward the first surface or the second surface with respect to the first side surface portion. The first weight is disposed such that, when viewed from the direction along the Z-axis, an outer edge portion of the first weight is inside or at the same position as the innermost portion in the first side surface portion and the second side surface portion.

[0006] The vibration device has the above-described vibrating element and a package for housing the vibrating element.

[0007] The method for manufacturing a vibrating element includes a frequency adjustment method for adjusting the frequency of the vibrating element. The vibrating element includes a base portion, a first surface, a second surface facing the first surface in a direction along the Z-axis, a first side surface, a second side surface facing the first side surface in a direction along the X-axis orthogonal to the Z-axis, and a third side surface located on the side opposite to the base portion, and has a vibrating arm extending from the base portion in a direction along the Y-axis orthogonal to the Z-axis and the X-axis, and a first weight disposed on the second surface. At least one of the first side surface, the second side surface, and the third side surface includes a first side surface portion inclined with respect to the direction along the Z-axis, and a second side surface portion inclined toward the first surface or the second surface with respect to the first side surface portion. The first weight is disposed such that, when viewed from the direction along the Z-axis, an outer edge portion of the first weight is inside or at the same position as the innermost portion in the first side surface portion and the second side surface portion. The frequency adjustment method includes a step of changing the oscillation frequency of the vibrating element by irradiating laser light from the first surface side in the direction along the Z-axis to remove at least a part of the first weight.

Brief Description of the Drawings

[0008]

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MODE FOR CARRYING OUT THE INVENTION

[0009] 1. Embodiment 1 The vibration element 1 according to Embodiment 1 will be described with reference to FIGS. 1 to 6. For convenience of explanation, in the following figures, the X-axis, Y-axis, and Z-axis are shown as three mutually orthogonal axes. The direction along the X-axis is referred to as the "X direction", the direction along the Y-axis is referred to as the "Y direction", and the direction along the Z-axis is referred to as the "Z direction". Also, the arrow side of each axis is also referred to as the "plus side", and the side opposite to the arrow is also referred to as the "minus side". Also, the Z-direction plus side is also referred to as "up", and the Z-direction minus side is also referred to as "down". Further, in a plan view from the Z direction, the surface on the Z-direction plus side is described as the upper surface, and the surface on the Z-direction minus side, which is the opposite side of this upper surface, is described as the lower surface. In this embodiment, the X-axis, Y-axis, and Z-axis correspond to the electrical axis, mechanical axis, and optical axis, which are the crystal axes of quartz, as will be described later. Also, in the following figures, for easier understanding of the explanation, there may be cases where they are drawn at scales different from the actual ones.

[0010] As shown in FIG. 1, the vibration element 1 is a tuning fork type crystal oscillator. The vibration element 1 includes a vibrating body 41, an electrode 45 for vibrating the vibrating body 41, and a metal film 46 for adjusting the frequency of the vibrating body 41.

[0011] The vibrating body 41 is formed from a Z-cut quartz plate, has an extent in the XY plane defined by the X-axis and Y-axis, and is in the shape of a flat plate having a thickness in the Z direction. The X-axis, Y-axis, and Z-axis respectively correspond to the electrical axis, mechanical axis, and optical axis, which are the crystal axes of quartz.

[0012] The vibrating body 41 has a first surface 101 and a second surface 102 facing the first surface 101 in the Z direction. In the present embodiment, the first surface 101 is the main surface on the plus side in the Z direction of the vibrating body 41, and the second surface 102 is the main surface on the minus side in the Z direction of the vibrating body 41. That is, the first surface 101 is the upper surface of the vibrating body 41, and the second surface 102 is the lower surface of the vibrating body 41.

[0013] Note that the constituent material of the vibrating body 41 is not particularly limited. For example, various piezoelectric materials such as lead zirconate titanate may be used, or materials other than piezoelectric materials such as silicon substrates may be used.

[0014] The vibrating body 41 has a base portion 42 and a pair of vibrating arms 43 and 44 extending from the base portion 42 in the Y direction. In the present embodiment, the vibrating arms 43 and 44 extend from the base portion 42 to the plus side in the Y direction.

[0015] The vibrating arms 43 and 44 include the first surface 101 which is the upper surface, the second surface 102 which is the lower surface, a first side surface 111 connecting the first surface 101 and the second surface 102, a second side surface 112 facing the first side surface 111 in the X direction, and a third side surface 113 located on the side opposite to the base portion 42 and connecting the first surface 101 and the second surface 102. In the present embodiment, the first side surface 111 is the side surface on the plus side in the X direction of the vibrating arms 43 and 44, and the second side surface 112 is the side surface on the minus side in the X direction of the vibrating arms 43 and 44. The third side surface 113 is the side surface on the plus side in the Y direction of the vibrating arms 43 and 44, that is, the tip surface of the vibrating arms 43 and 44.

[0016] The vibrating arms 43 and 44 each have an arm portion 430 and 440 and a weight portion 431 and 441. The weight portions 431 and 441 are arranged at the tip portions of the vibrating arms 43 and 44 on the side opposite to the base portion 42. The arm portions 430 and 440 are arranged closer to the base portion 42 than the weight portions 431 and 441 and connect the weight portions 431 and 441 to the base portion 42.

[0017] On the arm portions 430 and 440 of the vibrating arms 43 and 44, electrodes 45 are disposed. On the weight portions 431 and 441 of the vibrating arms 43 and 44, metal films 46 are disposed.

[0018] First, the arm portions 430 and 440 of the vibrating arms 43 and 44 will be described. As shown in FIGS. 1 and 2, the arm portion 430 of the vibrating arm 43 has a groove-shaped recess 432 that opens to the first surface 101 and a groove-shaped recess 433 that opens to the second surface 102. Similarly, the arm portion 440 of the vibrating arm 44 has a groove-shaped recess 442 that opens to the first surface 101 and a groove-shaped recess 443 that opens to the second surface 102. Thus, the arm portions 430 and 440 each have a substantially H-shaped cross-sectional shape having groove-shaped recesses 432 and 442 on their respective first surfaces 101 and groove-shaped recesses 433 and 443 on their respective second surfaces 102.

[0019] On the arm portions 430 and 440 of the vibrating arms 43 and 44, a signal electrode 481 and a ground electrode 482 are disposed as the electrodes 45. The signal electrode 481 is disposed on the first surface 101 and the second surface 102 of the vibrating arm 43 and on the first side surface 111 and the second side surface 112 of the vibrating arm 44. The ground electrode 482 is disposed on the first side surface 111 and the second side surface 112 of the vibrating arm 43 and on the first surface 101 and the second surface 102 of the vibrating arm 44.

[0020] By applying a drive signal to the signal electrode 481, the vibrating arms 43 and 44 bend and vibrate so as to repeat approaching and separating.

[0021] Next, the weight portions 431 and 441 of the vibrating arms 43 and 44 will be described. As shown in FIGS. 3 and 4, the first side surface 111 of the weight portion 431 of the vibrating arm 43 includes an upper side surface portion 121 and a lower side surface portion 122. The upper end of the upper side surface portion 121 on the first side surface 111 is connected to the first surface 101. The lower end of the upper side surface portion 121 on the first side surface 111 is connected to the upper end of the lower side surface portion 122 on the first side surface 111. The lower end of the lower side surface portion 122 on the first side surface 111 is connected to the second surface 102.

[0022] In this embodiment, the upper side surface portion 121 of the first side surface 111 of the weight portion 431 is parallel to the Z direction, and the lower side surface portion 122 of the first side surface 111 of the weight portion 431 is inclined with respect to the Z direction.

[0023] That is, the lower side surface portion 122 of the first side surface 111 of the weight portion 431 is the first side surface inclined with respect to the Z direction in the present invention. And the upper side surface portion 121 of the first side surface 111 of the weight portion 431 is the second side surface inclined toward the first surface 101 with respect to the first side surface in the present invention. In other words, the first side surface 111 of the weight portion 431 includes a lower side surface portion 122 that is the first side surface inclined with respect to the Z direction, and an upper side surface portion 121 that is the second side surface inclined toward the first surface 101 with respect to the lower side surface portion 122 that is the first side surface.

[0024] Further, the second side surface 112 of the weight portion 431 of the vibrating arm 43 includes an upper side surface portion 123 and a lower side surface portion 124. The upper end of the upper side surface portion 123 of the second side surface 112 is connected to the first surface 101. The lower end of the upper side surface portion 123 of the second side surface 112 is connected to the upper end of the lower side surface portion 124 of the second side surface 112. The lower end of the lower side surface portion 124 of the second side surface 112 is connected to the second surface 102.

[0025] In this embodiment, the upper side surface portion 123 of the second side surface 112 of the weight portion 431 is parallel to the Z direction, and the lower side surface portion 124 of the second side surface 112 of the weight portion 431 is inclined with respect to the Z direction.

[0026] That is, the lower side surface portion 124 of the second side surface 112 of the weight portion 431 is the first side surface inclined with respect to the Z direction in the present invention. And the upper side surface portion 123 of the second side surface 112 of the weight portion 431 is the second side surface inclined toward the first surface 101 with respect to the first side surface in the present invention. In other words, the second side surface 112 of the weight portion 431 includes a lower side surface portion 124 that is a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 123 that is a second side surface portion inclined toward the first surface 101 with respect to the lower side surface portion 124 that is the first side surface portion.

[0027] As shown in FIG. 5, the third side surface 113 of the weight portion 431 of the vibrating arm 43 includes an upper side surface portion 125 and a lower side surface portion 126. The upper end of the upper side surface portion 125 of the third side surface 113 is connected to the first surface 101. The lower end of the upper side surface portion 125 of the third side surface 113 is connected to the upper end of the lower side surface portion 126 of the third side surface 113. The lower end of the lower side surface portion 126 of the third side surface 113 is connected to the second surface 102.

[0028] In the present embodiment, the upper side surface portion 125 of the third side surface 113 of the weight portion 431 is parallel to the Z direction, and the lower side surface portion 126 of the third side surface 113 of the weight portion 431 is inclined with respect to the Z direction.

[0029] That is, the lower side surface portion 126 of the third side surface 113 of the weight portion 431 is a first side surface portion inclined with respect to the Z direction in the present invention. And the upper side surface portion 125 of the third side surface 113 of the weight portion 431 is a second side surface portion inclined toward the first surface 101 with respect to the first side surface portion in the present invention. In other words, the third side surface 113 of the weight portion 431 includes a lower side surface portion 126 that is a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 125 that is a second side surface portion inclined toward the first surface 101 with respect to the lower side surface portion 126 that is the first side surface portion.

[0030] Also, as shown in FIGS. 1 and 3 to 6, the weight portion 441 of the vibrating arm 44 has substantially the same basic configuration as the weight portion 431 of the vibrating arm 43. The first side surface 111 of the weight portion 441 of the vibrating arm 44 includes a lower side surface portion 122 as a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 121 as a second side surface portion inclined toward the first surface 101 with respect to the lower side surface portion 122 as the first side surface portion. The second side surface 112 of the weight portion 441 includes a lower side surface portion 124 as a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 123 as a second side surface portion inclined toward the first surface 101 with respect to the lower side surface portion 124 as the first side surface portion. The third side surface 113 of the weight portion 441 includes a lower side surface portion 126 as a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 125 as a second side surface portion inclined toward the first surface 101 with respect to the lower side surface portion 126 as the first side surface portion.

[0031] Next, the metal film 46 disposed on the weight portions 431 and 441 of the vibrating arms 43 and 44 will be described. As shown in FIGS. 1 and 3 to 6, the metal film 46 is disposed on the second surface 102, the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441 of the vibrating arms 43 and 44, respectively. The metal film 46 is for adjusting the resonance frequency of the vibrating element 1 or adjusting the vibration balance of the vibrating arms 43 and 44. As will be described later, in the frequency adjustment step included in the frequency adjustment method of the vibrating element 1, the laser beam LB is irradiated onto the metal film 46 to remove a part of the metal film 46, and by reducing the mass of the vibrating arms 43 and 44, the resonance frequency of the vibrating element 1 can be adjusted. Note that the material constituting the metal film 46 is not particularly limited, and for example, it can be composed of a metal material mainly containing gold (Au), silver (Ag), aluminum (Al), or the like. In the present embodiment, the metal film 46 is composed of gold (Au).

[0032] The metal film 46 disposed on the second surface 102 of the weight portions 431 and 441 of the vibrating arms 43 and 44 is the first weight 461 disposed on the second surface 102 in the present invention.

[0033] Figures 1 and 3 to 6 show the state after the frequency adjustment process, that is, the state in which the laser beam LB is irradiated and a part of the first weight 461 is removed. As shown in Figures 1 and 4 to 6, the removal region 462 on the second surface 102 is the region where the laser beam LB is irradiated and the first weight 461 is removed in the frequency adjustment process.

[0034] In the present embodiment, the first weight 461 and the removal region 462 on the second surface 102 are arranged side by side in the Y direction, which is the longitudinal direction of the vibrating arms 43 and 44, and the removal region 462 is located on the tip side of the vibrating arms 43 and 44 with respect to the first weight 461, that is, on the plus side in the Y direction. By arranging the removal region 462 on the tip side of the vibrating arms 43 and 44 rather than the first weight 461, in other words, by removing the tip side of the first weight 461, the amount of frequency change per unit mass of the removed first weight 461 can be made larger. Therefore, in the frequency adjustment process, a sufficient frequency adjustment range can be ensured. However, the arrangement of the first weight 461 and the removal region 462 is not particularly limited. For example, the removal region 462 may be located on the minus side in the Y direction of the first weight 461.

[0035] Next, the arrangement of the first weight 461 with respect to the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441 of the vibrating arms 43 and 44 will be described.

[0036] First, the arrangement of the first weight 461 with respect to the first side surface 111 of the weight portion 431 of the vibrating arm 43 will be described. As shown in Figure 3 and as described above, the lower side surface portion 122 of the first side surface 111 of the weight portion 431 is inclined with respect to the Z direction. Specifically, the lower side surface portion 122 of the first side surface 111 of the weight portion 431 is inclined inward of the weight portion 431 from the first surface 101 toward the second surface 102. That is, on the first side surface 111 of the weight portion 431, the innermost portion 131 of the lower side surface portion 122, which is the first side surface portion, and the upper side surface portion 121, which is the second side surface portion, is the lower end portion of the lower side surface portion 122 where the lower side surface portion 122 is connected to the second surface 102.

[0037] In the present invention, the "innermost part" refers to the part located at the innermost of the weight parts 431 and 441 on each of the first side surface 111, the second side surface 112, and the third side surface 113 when the first side surface 111, the second side surface 112, and the third side surface 113 are projected in the Z direction.

[0038] On the first side surface 111 of the weight part 431, a virtual line parallel to the Z direction passing through the innermost part 131 in the lower side surface part 122 which is the first side surface part and the upper side surface part 121 which is the second side surface part is defined as the virtual line L1, and a virtual line parallel to the Z direction passing through the outer edge part 463A on the first side surface 111 side of the first weight 461 disposed on the second surface 102 of the weight part 431 is defined as the virtual line L2. Then, the virtual line L1 and the virtual line L2 are at the same position in a side view from the Y direction orthogonal to the Z direction.

[0039] In the present invention, "the same" and "equal" include manufacturing variations and the like, and mean substantially the same or substantially equal.

[0040] Also, as shown in FIG. 1, in the weight part 431, the innermost part 131 in the lower side surface part 122 which is the first side surface part and the upper side surface part 121 which is the second side surface part on the first side surface 111 and the outer edge part 463A on the first side surface 111 side of the first weight 461 are at the same position. That is, the first weight 461 in the weight part 431 is arranged such that, when viewed from the Z direction, the outer edge part 463A on the first side surface 111 side of the first weight 461 is at the same position as the innermost part 131 in the lower side surface part 122 which is the first side surface part and the upper side surface part 121 which is the second side surface part on the first side surface 111.

[0041] In this way, when viewed from the Z direction, the outer edge portion 463A on the first side surface 111 side of the first weight 461 is arranged at the same position as the innermost portion 131 of the lower side surface portion 122 which is the first side surface portion and the upper side surface portion 121 which is the second side surface portion on the first side surface 111. By arranging the first weight 461 in this manner, when irradiating the first weight 461 with the laser beam LB, refraction or shielding of the laser beam LB on the lower side surface portion 122 and the upper side surface portion 121 of the first side surface 111 can be suppressed. For this reason, the laser beam LB can be sufficiently irradiated onto the first weight 461, and the formation of foreign matters such as burrs is suppressed. Therefore, it is possible to provide the vibration element 1 in which a change in frequency due to the fall of foreign matters such as burrs hardly occurs.

[0042] Next, the arrangement of the first weight 461 with respect to the second side surface 112 of the weight portion 431 of the vibrating arm 43 will be described. As shown in FIG. 3 and as described above, the lower side surface portion 124 of the second side surface 112 of the weight portion 431 is inclined with respect to the Z direction. Specifically, the lower side surface portion 124 of the second side surface 112 of the weight portion 431 is inclined inward of the weight portion 431 from the first surface 101 toward the second surface 102. That is, on the second side surface 112 of the weight portion 431, the innermost portion 132 of the lower side surface portion 124 which is the first side surface portion and the upper side surface portion 123 which is the second side surface portion is the lower end portion of the lower side surface portion 124 where the lower side surface portion 124 is connected to the second surface 102.

[0043] On the second side surface 112 of the weight portion 431, a virtual line parallel to the Z direction passing through the innermost portion 132 of the lower side surface portion 124 which is the first side surface portion and the upper side surface portion 123 which is the second side surface portion is defined as the virtual line L3, and a virtual line parallel to the Z direction passing through the outer edge portion 463B on the second side surface 112 side of the first weight 461 arranged on the second surface 102 of the weight portion 431 is defined as the virtual line L4. Then, the virtual line L3 and the virtual line L4 are at the same position in a side view from the Y direction orthogonal to the Z direction.

[0044] Further, as shown in FIG. 1, in the weight portion 431, the innermost portion 132 of the lower side surface portion 124, which is the first side surface portion on the second side surface 112, and the upper side surface portion 123, which is the second side surface portion, is in the same position as the outer edge portion 463B on the second side surface 112 side of the first weight 461. That is, the first weight 461 in the weight portion 431 is arranged such that when viewed from the Z direction, the outer edge portion 463B on the second side surface 112 side of the first weight 461 is in the same position as the innermost portion 132 of the lower side surface portion 124, which is the first side surface portion on the second side surface 112, and the upper side surface portion 123, which is the second side surface portion.

[0045] In this way, when viewed from the Z direction, by arranging the first weight 461 such that the outer edge portion 463B on the second side surface 112 side of the first weight 461 is in the same position as the innermost portion 132 of the lower side surface portion 124, which is the first side surface portion on the second side surface 112, and the upper side surface portion 123, which is the second side surface portion, it is possible to suppress the refraction or shielding of the laser beam LB also on the second side surface 112, similar to the first side surface 111. For this reason, the laser beam LB can be sufficiently irradiated onto the first weight 461, generation of foreign matters such as burrs can be suppressed, and the vibration element 1 in which a change in frequency hardly occurs can be provided.

[0046] Next, the arrangement of the first weight 461 with respect to the third side surface 113 in the weight portion 431 of the vibrating arm 43 will be described. As shown in FIG. 5, also, as described above, the lower side surface portion 126 of the third side surface 113 in the weight portion 431 is inclined with respect to the Z direction. Specifically, the lower side surface portion 126 of the third side surface 113 in the weight portion 431 is inclined inward of the weight portion 431 from the first surface 101 toward the second surface 102. That is, in the third side surface 113 of the weight portion 431, the innermost portion 133 of the lower side surface portion 126, which is the first side surface portion, and the upper side surface portion 125, which is the second side surface portion, is the lower end portion of the lower side surface portion 126 where the lower side surface portion 126 is connected to the second surface 102.

[0047] On the third side surface 113 of the hammer part 431, a virtual line parallel to the Z direction passing through the innermost part 133 in the lower side surface part 126 which is the first side surface part and the upper side surface part 125 which is the second side surface part is defined as the virtual line L5, and a virtual line parallel to the Z direction passing through the outer edge part 463C on the third side surface 113 side of the first hammer 461 arranged on the second surface 102 of the hammer part 431 is defined as the virtual line L6. Then, the virtual line L6 is located on the minus Y direction side in a side view from the X direction orthogonal to the Z direction with respect to the virtual line L5. That is, the virtual line L6 parallel to the Z direction passing through the outer edge part 463C is located on the minus Y direction side which is the direction toward the inside from the virtual line L5 parallel to the Z direction passing through the innermost part 133 in the first side surface part and the second side surface part of the third side surface 113.

[0048] Also, as shown in FIG. 1, in the hammer part 431, the outer edge part 463C on the third side surface 113 side of the first hammer 461 is located more inside than the innermost part 133 in the lower side surface part 126 which is the first side surface part and the upper side surface part 125 which is the second side surface part of the third side surface 113.

[0049] In this way, when viewed from the Z direction, by arranging the first hammer 461 so that the outer edge part 463C on the third side surface 113 side of the first hammer 461 is located more inside than the innermost part 133 in the lower side surface part 126 which is the first side surface part and the upper side surface part 125 which is the second side surface part of the third side surface 113, similar to the first side surface 111 and the second side surface 112, it is possible to suppress the refraction or shielding of the laser light LB also on the third side surface 113. For this reason, the laser light LB can be sufficiently irradiated to the first hammer 461, generation of foreign matters such as burrs can be suppressed, and the vibration element 1 in which a change in frequency hardly occurs can be provided.

[0050] Next, the arrangement of the first hammer 461 with respect to the first side surface 111, the second side surface 112, and the third side surface 113 of the hammer part 441 of the vibrating arm 44 will be described. As shown in FIGS. 1 and 3 to 6, the weight portion 441 of the vibrating arm 44 has substantially the same basic configuration as the weight portion 431 of the vibrating arm 43. Therefore, the arrangement of the first weight 461 with respect to the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portion 441 of the vibrating arm 44 is the same as that of the weight portion 431 of the vibrating arm 43. Specifically, when viewed from the Z direction, the first weight 461 is arranged such that the outer edge portions 463A and 463B of the first weight 461 are at the same positions as the innermost portions 131 in the first side portions and the second side portions of the first side surface 111 and the innermost portions 132 in the first side portions and the second side portions of the second side surface 112, respectively. When viewed from the Z direction, the first weight 461 is arranged such that the outer edge portion 463C of the first weight 461 is inside the innermost portions 133 in the first side portions and the second side portions of the third side surface 113. Thereby, refraction or shielding of the laser beam LB by the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portion 441 can be suppressed. For this reason, the laser beam LB can be sufficiently irradiated onto the first weight 461, generation of foreign matters such as burrs can be suppressed, and the vibrating element 1 in which a change in frequency hardly occurs can be provided.

[0051] In the present embodiment, as described above, the three side surfaces of the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441 of the vibrating arms 43 and 44 are lower side surface portions 122, 124, and 126 that are first side surface portions inclined with respect to the Z direction, and upper side surface portions 121, 123, and 125 that are second side surface portions inclined toward the first surface 101 with respect to the first side surface portion, respectively. And the first weight 461 is arranged such that when viewed from the Z direction, the outer edge portions 463A, 463B, and 463C of the first weight 461 are respectively inside or at the same position as the innermost portions 131, 132, and 133 of the lower side surface portions 122, 124, and 126 that are the first side surface portions and the upper side surface portions 121, 123, and 125 that are the second side surface portions. Note that at least one of the first side surface 111, the second side surface 112, and the third side surface 113 may be configured as in the present embodiment. However, if the three side surfaces of the first side surface 111, the second side surface 112, and the third side surface 113 are configured as in the present embodiment, generation of foreign matters such as burrs is suppressed on the three side surfaces of the first side surface 111, the second side surface 112, and the third side surface 113. Therefore, it is possible to provide the vibration element 1 in which a change in frequency is less likely to occur as compared with the case where one or two of the three side surfaces of the first side surface 111, the second side surface 112, and the third side surface 113 are configured as in the present embodiment.

[0052] Further, by configuring at least one of the first side surface 111 and the second side surface 112 of the weight portions 431 and 441 of the vibrating arms 43 and 44 as in the present embodiment, it is possible to provide a tuning fork type crystal oscillator in which a change in frequency is less likely to occur as the vibration element 1. That is, when a tuning fork type crystal oscillator is formed by wet etching, due to the anisotropy of the crystal, the first side surface 111 and the second side surface 112 are likely to have a shape with a convex cross section as in the prior art. However, even if it has a shape with a convex cross section, when irradiating the first weight 461 with the laser beam LB in the frequency adjustment step of the vibration element 1 described later, refraction or shielding of the laser beam LB on the first side surface 111 or the second side surface 112 can be suppressed. Therefore, it is possible to provide a tuning fork type crystal oscillator in which a change in frequency is less likely to occur as the vibration element 1.

[0053] Further, by configuring the third side surface 113 of the weight portions 431 and 441 of the vibrating arms 43 and 44 as in this embodiment, it is possible to increase the amount of frequency change in the frequency adjustment process of the vibrating element 1 described later, and to provide a vibrating element 1 in which a change in frequency after the frequency adjustment process hardly occurs. That is, the third side surface 113 is the tip surface of the vibrating arms 43 and 44. By suppressing the refraction or shielding of the laser beam LB on the third side surface 113 which is the tip surface of the vibrating arms 43 and 44, it becomes easy to remove the first weight 461 from the tip side of the vibrating arms 43 and 44. Therefore, the amount of frequency change can be increased in the frequency adjustment process. In addition, since the generation of foreign matters such as burrs on the tip side of the vibrating arms 43 and 44 can be suppressed, it is possible to provide a vibrating element 1 in which a change in frequency after the frequency adjustment process hardly occurs.

[0054] Also, as shown in FIG. 3, the width W4 in the X direction on the second surface 102 of the weight portions 431 and 441 is smaller than the width W3 in the X direction on the first surface 101 of the weight portions 431 and 441. Thereby, it becomes easy to form the first weight 461 over the entire width W4 in the X direction on the second surface 102 of the weight portions 431 and 441, and it is possible to provide a vibrating element 1 that is easy to manufacture.

[0055] Also, as shown in FIG. 2, the width W1 in the X direction on the first surface 101 of the arm portions 430 and 440 is equal to the width W2 in the X direction on the second surface 102 of the arm portions 430 and 440. As described above, a signal electrode 481 and a ground electrode 482 are arranged on the arm portions 430 and 440, and by applying a drive signal to the signal electrode 481, the vibrating arms 43 and 44 vibrate. By making the width W1 in the X direction on the first surface 101 of the arm portions 430 and 440 equal to the width W2 in the X direction on the second surface 102 of the arm portions 430 and 440, the vibration balance of the vibrating arms 43 and 44 is improved, and vibration leakage can be reduced. Thereby, it is possible to provide a vibrating element 1 having excellent vibration efficiency.

[0056] Next, a method for manufacturing the vibrating element 1 according to this embodiment will be described with reference to FIGS. 7 to 11.

[0057] The manufacturing method of the vibration element 1 includes a frequency adjustment method for adjusting the frequency of the vibration element 1. And, as shown in FIG. 7, the frequency adjustment method for adjusting the frequency of the vibration element 1 includes a preparation step of preparing the vibration element 1, a frequency measurement step of measuring the oscillation frequency of the vibration element 1, and a frequency adjustment step of changing the oscillation frequency of the vibration element 1 to adjust the oscillation frequency of the vibration element 1 to a target value.

[0058] 1.1 Preparation step First, in step S1, as shown in FIG. 8, a quartz wafer 40 is prepared, and a plurality of vibrating bodies 41 are formed on the quartz wafer 40 by patterning the quartz wafer 40 using photolithography techniques and etching techniques. Next, an electrode 45 is formed on the surface of the vibrating body 41 by sputtering or the like, and further, a metal film 46 is formed on the weight portions 431 and 441 of the vibrating arms 43 and 44 by evaporation or the like. In the present embodiment, as described above, the metal film 46 is formed on the second surface 102, the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441. The metal film 46 formed on the second surface 102 is the first weight 461.

[0059] 1.2 Frequency measurement step Next, in step S2, for example, a probe of a frequency measuring device having an oscillation circuit is brought into contact with the electrode 45 formed on the surface of the vibrating body 41 to measure the oscillation frequency of the vibration element 1.

[0060] 1.3 Frequency adjustment step Next, in step S3, based on the oscillation frequency measured in step S2, the frequency of the vibration element 1 is adjusted. Specifically, as shown in FIGS. 9 to 11, the first weight 461 disposed on the second surface 102 of the weight portions 431 and 441 is irradiated with a laser beam LB, and a part of the first weight 461 is removed. In the present embodiment, the laser beam LB is irradiated in a direction along the Z direction from the first surface 101 side of the vibration element 1 toward the second surface 102. By removing a part of the first weight 461 and reducing the mass of the vibrating arms 43 and 44, the oscillation frequency of the vibration element 1 can be changed and adjusted to a target frequency. Since the basic configurations of the weight portion 431 of the vibrating arm 43 and the weight portion 441 of the vibrating arm 44 are the same, in FIGS. 10 and 11, among the weight portions 431 and 441 of the vibrating arms 43 and 44, the weight portion 431 of the vibrating arm 43 is illustrated.

[0061] As shown in FIG. 10, when viewed from the Z direction, which is the direction in which the laser beam LB is irradiated, the laser beam LB irradiated inside or at the same position as the innermost portion 131 of the lower side surface portion 122, which is the first side surface portion of the first side surface 111, and the upper side surface portion 121, which is the second side surface portion, is suppressed from being refracted or blocked by the first side surface 111. That is, when removing the first weight 461 disposed inside or at the same position as the innermost portion 131 of the first side surface portion and the second side surface portion of the first side surface 111 when viewed from the Z direction, the first weight 461 disposed inside or at the same position as the innermost portion 131 can be sufficiently irradiated with the laser beam LB. Therefore, when removing the first weight 461, the formation of foreign matters such as burrs is suppressed, so that it is possible to provide the vibration element 1 in which a change in frequency due to the fall of foreign matters such as burrs hardly occurs.

[0062] Also, similarly, when viewed from the Z direction, the laser light LB irradiated on the inner side or at the same position as the innermost part 132 of the lower side surface part 124 which is the first side surface part and the upper side surface part 123 which is the second side surface part on the second side surface 112 is less refracted or shielded by the second side surface 112. Therefore, the laser light LB can be sufficiently irradiated onto the first weight 461 disposed on the inner side of the innermost part 132 or at the same position as the innermost part 132. Thus, when removing the first weight 461, the formation of foreign matters such as burrs is suppressed, and the vibration element 1 with a less likely occurrence of frequency change can be provided.

[0063] Also, as shown in FIG. 11, when viewed from the Z direction, the laser light LB irradiated on the inner side and at the same position as the innermost part 133 of the lower side surface part 126 which is the first side surface part or the upper side surface part 125 which is the second side surface part on the third side surface 113 is less refracted or shielded by the third side surface 113. Therefore, the laser light LB can be sufficiently irradiated onto the first weight 461 disposed on the inner side of the innermost part 133 or at the same position as the innermost part 133. Thus, when removing the first weight 461, the formation of foreign matters such as burrs is suppressed, and the vibration element 1 with a less likely occurrence of frequency change can be provided.

[0064] In this embodiment, the frequency adjustment step is performed after the frequency measurement step of step S2, but it is not limited thereto. In the frequency adjustment step, the oscillation frequency of the vibration element 1 may be adjusted while measuring the frequency.

[0065] In addition, the laser beam LB used in the frequency adjustment process is not particularly limited. For example, pulsed laser beams such as YAG and excimer lasers, or continuous oscillation laser beams such as carbon dioxide lasers may be used. In this embodiment, a pulsed laser beam is used as the laser beam LB. That is, by continuously irradiating the laser beam LB focused in a spot shape, a part of the first weight 461 is removed. In this way, by using a pulsed laser beam as the laser beam LB, the irradiation amount, that is, the energy amount, of the laser beam LB per unit area on the first weight 461 can be controlled by changing the irradiation time and irradiation pitch while keeping the intensity of the laser beam LB constant without changing it. Therefore, the laser beam LB is stable, and the frequency adjustment process can be performed with high accuracy.

[0066] In this embodiment, a part of the first weight 461 is removed in the frequency adjustment process, but all of the first weight 461 may be removed. That is, by removing at least a part of the first weight 461, the oscillation frequency of the vibration element 1 can be changed, and the vibration element 1 can be adjusted to the target frequency.

[0067] As described above, according to this embodiment, the following effects can be obtained. The vibrating element 1 includes a base portion 42, a first surface 101, a second surface 102 facing the first surface 101 in the Z direction, a first side surface 111, a second side surface 112 facing the first side surface 111 in the X direction, and a third side surface 113 located on the side opposite to the base portion 42, and has vibrating arms 43 and 44 extending in the Y direction from the base portion 42, and a first weight 461 disposed on the second surface 102. And at least one of the first side surface 111, the second side surface 112, and the third side surface 113 of the vibrating element 1 is a lower side surface portion 122, 124, 126 which is a first side surface portion inclined with respect to the Z direction, and an upper side surface portion 121, 123, 125 which is a second side surface portion inclined toward the first surface 101 with respect to the first side surface portion. And when viewed from the Z direction, the outer edge portions 463A, 463B, 463C of the first weight 461 are located inside or at the same position as the innermost portions 131, 132, 133 in the lower side surface portions 122, 124, 126 which are the first side surface portions and the upper side surface portions 121, 123, 125 which are the second side surface portions on the first side surface 111, the second side surface 112, and the third side surface 113, respectively. Thereby, the laser beam LB can be sufficiently irradiated to the first weight 461, formation of foreign matters such as burrs in the first weight 461 is suppressed, and a vibrating element 1 in which a change in frequency due to falling of foreign matters such as burrs is unlikely to occur can be provided.

[0068] In the present embodiment, the upper side surface portions 121, 123, 125 which are the second side surface portions on the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431, 441 are parallel to the Z direction, but may be inclined with respect to the Z direction.

[0069] Further, in the present embodiment, the lower side surface portions 122, 124, 126 which are the first side surface portions on the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431, 441 are inclined inward of the weight portion 431 from the first surface 101 toward the second surface 102, but may be inclined outward of the weight portion 431.

[0070] In addition, in the present embodiment, the lower side surface portions 122, 124, and 126 on the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441 are the first side surface portions in the present invention, and the upper side surface portions 121, 123, and 125 are the second side surface portions in the present invention. However, the upper side surface portions 121, 123, and 125 may be arranged as the first side surface portions, and the lower side surface portions 122, 124, and 126 may be arranged as the second side surface portions. When the lower side surface portions 122, 124, and 126 are arranged as the second side surface portions, the lower side surface portions 122, 124, and 126 serving as the second side surface portions are inclined toward the second surface 102 with respect to the upper side surface portions 121, 123, and 125 serving as the first side surface portions.

[0071] In addition, in the present embodiment, on the first side surface 111, the second side surface 112, and the third side surface 113 of the weight portions 431 and 441, the upper end portions of the upper side surface portions 121, 123, and 125 are connected to the first surface 101. However, the upper end portions of the upper side surface portions 121, 123, and 125 and the first surface 101 may be connected via other side surface portions. Similarly, the lower end portions of the upper side surface portions 121, 123, and 125 and the upper end portions of the lower side surface portions 122, 124, and 126 may be connected via other side surface portions, or the upper end portions of the lower side surface portions 122, 124, and 126 and the second surface 102 may be connected via other side surface portions.

[0072] 2. Embodiment 2 Next, the vibration element 1a according to Embodiment 2 will be described with reference to FIGS. 12 to 15. The vibration element 1a of Embodiment 2 is the same as that of Embodiment 1 except that the shapes of the weight portions 431a and 441a of the vibration arms 43 and 44 are different. For components having the same configuration as those in the above-described Embodiment 1, the same reference numerals are given and their descriptions are omitted. FIGS. 12 to 15 show the state after the frequency adjustment process, that is, the state in which the laser beam LB is irradiated and a part of the first weight 461 is removed. Further, since the basic configurations of the weight portions 431a of the vibrating arms 43 and 441a of the vibrating arm 44 are the same, FIGS. 13 to 15 illustrate the weight portion 431a of the vibrating arm 43 among the weight portions 431a and 441a of the vibrating arms 43 and 44.

[0073] As shown in FIGS. 12, 13, and 15, metal films 46 are disposed on the second surface 102, the first side surface 111a, the second side surface 112a, and the third side surface 113a of the weight portions 431a and 441a of the vibrating arms 43 and 44, respectively. The metal film 46 disposed on the second surface 102 of the weight portion 431a of the vibrating arm 43 is the first weight 461. Further, as shown in FIGS. 12, 14, and 15, the removal region 462 on the second surface 102 is a region where the first weight 461 is removed by irradiation with the laser beam LB in the frequency adjustment process.

[0074] The first side surface 111a of the weight portion 431a of the vibrating arm 43 includes an upper side surface portion 121a and a lower side surface portion 122a. The upper end of the upper side surface portion 121a of the first side surface 111a is connected to the first surface 101. The lower end of the upper side surface portion 121a of the first side surface 111a is connected to the upper end of the lower side surface portion 122a of the first side surface 111a. The lower end of the lower side surface portion 122a of the first side surface 111a is connected to the second surface 102.

[0075] In the present embodiment, the upper side surface portion 121a of the first side surface 111a of the weight portion 431a is inclined with respect to the Z direction, and the lower side surface portion 122a of the first side surface 111a of the weight portion 431a is parallel to the Z direction.

[0076] That is, the upper side surface portion 121a of the first side surface 111a in the weight portion 431a is the first side surface inclined with respect to the Z direction in the present invention. And the lower side surface portion 122a of the first side surface 111a in the weight portion 431a is the second side surface inclined toward the second surface 102 with respect to the first side surface in the present invention. In other words, the first side surface 111a in the weight portion 431a includes an upper side surface portion 121a that is the first side surface inclined with respect to the Z direction, and a lower side surface portion 122a that is the second side surface inclined toward the second surface 102 with respect to the upper side surface portion 121a that is the first side surface.

[0077] In the present embodiment, the upper side surface portion 121a of the first side surface 111a in the weight portion 431a is inclined inward of the weight portion 431a from the first surface 101 toward the second surface 102. That is, in the first side surface 111a of the weight portion 431a, the innermost portion 131a in the upper side surface portion 121a that is the first side surface and the lower side surface portion 122a that is the second side surface is the lower end portion of the upper side surface portion 121a where the upper side surface portion 121a is connected to the lower side surface portion 122a.

[0078] As shown in FIG. 13, in the first side surface 111a of the weight portion 431a, a virtual line parallel to the Z direction passing through the innermost portion 131a in the upper side surface portion 121a that is the first side surface and the lower side surface portion 122a that is the second side surface is defined as a virtual line L1a, and a virtual line parallel to the Z direction passing through the outer edge portion 463A on the first side surface 111a side of the first weight 461 disposed on the second surface 102 of the weight portion 431a is defined as a virtual line L2a. Then, the virtual line L1a and the virtual line L2a are at the same position in a side view from the Y direction orthogonal to the Z direction.

[0079] Further, as shown in FIG. 12, in the weight portion 431a, the innermost portion 131a of the upper side surface portion 121a which is the first side surface portion of the first side surface 111a and the lower side surface portion 122a which is the second side surface portion is in the same position as the outer edge portion 463A on the first side surface 111a side of the first weight 461. That is, the first weight 461 in the weight portion 431a is arranged such that when viewed from the Z direction, the outer edge portion 463A on the first side surface 111a side of the first weight 461 is in the same position as the innermost portion 131a of the upper side surface portion 121a which is the first side surface portion of the first side surface 111a and the lower side surface portion 122a which is the second side surface portion.

[0080] In this way, when viewed from the Z direction, by arranging the first weight 461 such that the outer edge portion 463A on the first side surface 111a side of the first weight 461 is in the same position as the innermost portion 131a of the upper side surface portion 121a which is the first side surface portion of the first side surface 111a and the lower side surface portion 122a which is the second side surface portion, when irradiating the first weight 461 with the laser beam LB, refraction or shielding of the laser beam LB in the upper side surface portion 121a and the lower side surface portion 122a of the first side surface 111a can be suppressed. For this reason, the laser beam LB can be sufficiently irradiated to the first weight 461, formation of foreign matters such as burrs is suppressed, and thus a vibration element 1a in which a change in frequency due to the fall of foreign matters such as burrs hardly occurs can be provided.

[0081] Note that, as shown in FIGS. 13 and 14, in the present embodiment, the second side surface 112a of the weight portion 431a of the vibrating arm 43 is a plane parallel to the YZ plane, and as shown in FIG. 15, the third side surface 113a is a plane parallel to the XZ plane. That is, the second side surface 112a and the third side surface 113a of the weight portion 431a of the vibrating arm 43 do not include the first side surface portion and the second side surface portion in the present invention.

[0082] Although the weight portion 431a of the vibrating arm 43 has been described, the basic configurations of the weight portion 431a of the vibrating arm 43 and the weight portion 441a of the vibrating arm 44 are the same. Similar to the weight portion 431a of the vibrating arm 43, the first side surface 111a of the weight portion 441a of the vibrating arm 44 includes an upper side surface portion 121a which is a first side surface portion inclined with respect to the Z direction, and a lower side surface portion 122a which is a second side surface portion inclined toward the second surface 102 with respect to the first side surface portion. And when viewed from the Z direction, the first weight 461 is arranged such that the outer edge portion 463A on the first side surface 111a side of the first weight 461 is at the same position as the innermost portion 131a of the upper side surface portion 121a which is the first side surface portion and the lower side surface portion 122a which is the second side surface portion of the first side surface 111a. Thereby, the laser beam LB can be sufficiently irradiated onto the first weight 461, and a vibrating element 1a can be provided in which a change in frequency hardly occurs due to the dropping of foreign matters such as burrs.

[0083] As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained. One of the first side surface 111a, the second side surface 112a, and the third side surface 113a of the vibrating element 1a, the first side surface 111a, includes an upper side surface portion 121a which is a first side surface portion inclined with respect to the Z direction, and a lower side surface portion 122a which is a second side surface portion inclined toward the second surface 102 with respect to the first side surface portion. And the first weight 461 is arranged such that, when viewed from the Z direction, the outer edge portion 463A on the first side surface 111a side of the first weight 461 is at the same position as the innermost portion 131a of the upper side surface portion 121a which is the first side surface portion and the lower side surface portion 122a which is the second side surface portion. Thereby, the laser beam LB can be sufficiently irradiated onto the first weight 461, formation of foreign matters such as burrs in the first weight 461 is suppressed, and a vibrating element 1a in which a change in frequency hardly occurs can be provided.

[0084] Note that, in the present embodiment, the lower side surface portion 122a which is the second side surface portion of the first side surface 111a of the weight portions 431a, 441a is parallel to the Z direction, but may be inclined with respect to the Z direction.

[0085] In addition, in the present embodiment, the upper side surface portion 121a, which is the first side surface portion on the first side surface 111a of the weights 431a and 441a, is inclined inward of the weight 431a from the first surface 101 toward the second surface 102, but it may be inclined outward of the weight 431a.

[0086] 3. Embodiment 3 Next, the vibration element 1b according to Embodiment 3 will be described with reference to FIGS. 16 to 18. The vibration element 1b of Embodiment 3 is the same as that of Embodiment 1, except that the metal film 46 disposed on the lower side surface portion 122, which is the first side surface portion on the first side surface 111 of the weights 431 and 441 of the vibrating arms 43 and 44, becomes the second weight 465, and the second weight 465 has a removal region 466 removed by the laser beam LB. Regarding the same configurations as those in Embodiment 1 described above, the same reference numerals are given and the description thereof is omitted. FIGS. 16 to 18 show a state after the frequency fine adjustment process described later is completed, that is, a state in which the laser beam LB is irradiated and a part of the second weight 465 is removed. Further, since the basic configurations of the weight 431 of the vibrating arm 43 and the weight 441 of the vibrating arm 44 are the same, FIGS. 17 and 18 illustrate the weight 431 of the vibrating arm 43 among the weights 431 and 441 of the vibrating arms 43 and 44.

[0087] As shown in FIGS. 16 and 17, metal films 46 are disposed on the second surface 102, the first side surface 111, the second side surface 112, and the third side surface 113 of the weights 431 and 441 of the vibrating arms 43 and 44, respectively.

[0088] In the present embodiment, the metal film 46 disposed on the lower side surface portion 122, which is the first side surface portion on the first side surface 111 of the weights 431 and 441, is the second weight 465. In other words, the second weight 465 is disposed on the lower side surface portion 122, which is the first side surface portion on the first side surface 111 of the weights 431 and 441.

[0089] Further, as shown in FIGS. 16 and 18, the lower side surface portion 122, which is the first side surface portion on the first side surface 111, has a removal region 466. The removal region 466 is a region where the second weight 465 is removed by irradiating laser light LB in the frequency fine adjustment process described later.

[0090] Next, a method for manufacturing the vibration element 1b according to Embodiment 3 will be described with reference to FIGS. 19 to 21. The method for manufacturing the vibration element 1b of Embodiment 3 is the same as that of Embodiment 1, except that it has a frequency measurement step which is Step S4 and a frequency fine adjustment step which is Step S5. Note that, for the same configurations as those in Embodiment 1 described above, the same reference numerals are given and the description thereof is omitted. Also, since the basic configurations of the weight portions 431 of the vibrating arms 43 and 441 of the vibrating arm 44 are the same, in FIG. 21, among the weight portions 431 and 441 of the vibrating arms 43 and 44, the weight portion 431 of the vibrating arm 43 is illustrated.

[0091] The method for manufacturing the vibration element 1b includes a frequency adjustment method for adjusting the frequency of the vibration element 1b. And, as shown in FIG. 19, the frequency adjustment method for adjusting the frequency of the vibration element 1b includes a preparation step of preparing the vibration element 1b, a frequency measurement step of measuring the oscillation frequency of the vibration element 1b, a frequency adjustment step of adjusting the oscillation frequency of the vibration element 1b, a frequency measurement step of measuring the oscillation frequency of the vibration element 1b, and a frequency fine adjustment step of changing the oscillation frequency of the vibration element 1b and finely adjusting the oscillation frequency of the vibration element 1b to a target value.

[0092] The preparation step which is Step S1, the frequency measurement step which is Step S2, and the frequency adjustment step which is Step S3 are the same steps as those in Embodiment 1, and thus the detailed description thereof is omitted.

[0093] 1.1 Preparation Step First, in step S1, a quartz wafer 40 is prepared, and a plurality of vibrating elements 41 are formed on the quartz wafer 40. Next, an electrode 45 and a metal film 46 are formed on the surface of the vibrating element 41. In the present embodiment, as described above, the metal film 46 formed on the second surface 102 of the weight portions 431 and 441 is the first weight 461, and the metal film 46 formed on the lower side surface portion 122, which is the first side surface portion on the first side surface 111 of the weight portions 431 and 441, is the second weight 465.

[0094] 1.2 Frequency measurement step Next, in step S2, the oscillation frequency of the vibration element 1b is measured.

[0095] 1.3 Frequency adjustment step Next, in step S3, based on the oscillation frequency measured in step S2, the frequency of the vibration element 1 is adjusted. Specifically, the first weight 461 disposed on the second surface 102 of the weight portions 431 and 441 is irradiated with a laser beam LB to remove a part of the first weight 461.

[0096] 1.4 Frequency measurement step Next, in step S4, in the same manner as in step S2, the probe of the frequency measurement device having an oscillation circuit is brought into contact with the electrode 45 formed on the surface of the vibrating element 41, and the oscillation frequency of the vibration element 1b is measured.

[0097] 1.5 Fine frequency adjustment step Next, in step S5, based on the oscillation frequency measured in step S4, the frequency of the vibration element 1b is finely adjusted. Specifically, as shown in FIGS. 20 and 21, the second weight 465 disposed on the lower side surface portion 122, which is the first side surface portion on the first side surface 111 of the weight portions 431 and 441, is irradiated with a laser beam LB to remove a part of the second weight 465.

[0098] In this embodiment, the laser beam LB is irradiated in the direction along the Z direction from the first surface 101 side of the vibrating element 1 toward the second surface 102. The position of the focus of the laser beam LB is at the position of the first weight 461 disposed on the second surface 102 so that the first weight 461 disposed on the second surface 102 can be efficiently removed in the frequency adjustment step which is step S3. That is, the position of the second weight 465 disposed on the lower side surface portion 122 which is the first side surface portion on the first side surface 111 of the weight portions 431, 441 does not coincide with the position of the focus of the laser beam LB irradiated to the second weight 465. Therefore, the irradiation amount, that is, the energy amount, of the laser beam LB per unit area irradiated to the second weight 465 is reduced compared to the energy amount of the laser beam LB per unit area irradiated to the first weight 461, and the removal amount of the second weight 465 per spot of the laser beam LB is reduced compared to the removal amount of the first weight 461 per spot of the laser beam LB.

[0099] Therefore, by removing a part of the second weight 465 in the frequency fine adjustment step which is step S5, the oscillation frequency of the vibrating element 1b can be changed with higher precision than in the frequency adjustment step which is step S3, and the oscillation frequency of the vibrating element 1b can be finely adjusted to the target frequency.

[0100] In this embodiment, the frequency fine adjustment step is performed after the frequency measurement step of step S4, but it is not limited thereto, and the oscillation frequency of the vibrating element 1b may be finely adjusted while measuring the frequency in the frequency fine adjustment step.

[0101] Also, in this embodiment, the metal film 46 formed on the lower side surface portion 122 which is the first side surface portion on the first side surface 111 of the weight portions 431, 441 is used as the second weight 465, but the metal film 46 formed on the lower side surface portion 124 which is the first side surface portion on the second side surface 112 or the metal film 46 formed on the lower side surface portion 126 which is the first side surface portion on the third side surface 113 may be used as the second weight 465.

[0102] As described above, according to this embodiment, in addition to the effects of Embodiment 1, the following effects can be obtained. The vibration element 1b has a second weight 465 disposed on a lower side surface portion 122 which is a first side surface portion on the first side surface 111 of the weights 431 and 441. Thereby, a vibration element 1b that enables easy fine adjustment of the frequency can be provided.

[0103] In this embodiment, in the frequency fine adjustment process described above, a part of the second weight 465 is removed, but all of the second weight 465 may be removed. That is, by removing at least a part of the second weight 465, the oscillation frequency of the vibration element 1b can be changed, and the vibration element 1b can be finely adjusted to a target frequency.

[0104] 4. Embodiment 4 Next, the vibration device 10 according to Embodiment 4 will be described with reference to FIG. 22. In the vibration device 10 according to Embodiment 4, any of the vibration elements 1, 1a, and 1b described above can be used. In this embodiment, an example in which the vibration element 1 described in Embodiment 1 is applied is shown. For the same components as those in Embodiment 1 described above, the same reference numerals are given and the description thereof is omitted. Also, in FIG. 22, illustration of the electrodes 45 provided on the vibration element 1 and the metal film 46 is omitted.

[0105] The vibration device 10 shown in FIG. 22 is used, for example, as an oscillator. Note that the vibration device 10 may be used as various sensors other than an oscillator, for example, an acceleration sensor, an angular velocity sensor, or the like. The vibration device 10 can be incorporated in a computer, a printer, a smartphone, a tablet terminal, a clock, a television, a head-mounted display, a video camera, a digital still camera, a car navigation device, an electronic game device, various medical devices, various measuring devices, various moving bodies, and the like.

[0106] As shown in FIG. 22, the vibration device 10 includes a package 13, and a vibration element 1 and a circuit element 16 housed in the package 13.

[0107] Package 13 includes a base 31 having a recess 311 opening on the upper surface, and a plate-like lid 32 joined to the upper surface of the base 31 via a joining member 33 so as to close the opening of the recess 311. Inside the package 13, an internal space S is formed by the recess 311, and the vibration element 1 and the circuit element 16 are housed in the internal space S.

[0108] For example, the base 31 can be made of ceramics such as alumina, and the lid 32 can be made of a metal material such as kovar. However, the constituent materials of the base 31 and the lid 32 are not particularly limited. For example, the lid 32 may be made of a glass material having light transmissibility.

[0109] Also, the internal space S is airtight and in a decompressed state, preferably a state closer to a vacuum. Thereby, the viscous resistance is reduced and the vibration characteristics of the vibration element 1 are improved. However, the atmosphere in the internal space S is not particularly limited. For example, it may be an atmosphere filled with an inert gas such as nitrogen or argon, or may be in an atmospheric pressure state or a pressurized state instead of a decompressed state.

[0110] Further, the recess 311 has a recess 311a opening on the upper surface of the base 31, a recess 311b opening on the bottom surface of the recess 311a and having a smaller opening width than the recess 311a, and a recess 311c opening on the bottom surface of the recess 311b and having a smaller opening width than the recess 311b.

[0111] A plurality of internal terminals 341 are arranged on the bottom surface of the recess 311a. A plurality of internal terminals 342 are arranged on the bottom surface of the recess 311b. A plurality of external terminals 343 are arranged on the lower surface of the base 31. Some of the plurality of internal terminals 342 are electrically connected to the internal terminals 341 via internal wirings (not shown) formed in the base 31, and the rest are electrically connected to the external terminals 343 via internal wirings (not shown).

[0112] The vibration element 1 is joined to the internal terminal 341 via the conductive joining member 12 at the base portion 42 of the vibration element 1. As a result, the vibration element 1 is fixed to the base 31 via the joining member 12, and the electrode 45 of the vibration element 1 and the internal terminal 341 are electrically connected.

[0113] The circuit element 16 is joined to the bottom surface of the recess 311c. The circuit element 16 includes, for example, an interface portion that communicates with an external host device, an oscillation circuit that oscillates the vibration element 1, and the like. Note that the circuit element 16 may be omitted or may be disposed outside the package 13. Further, the circuit element 16 is electrically connected to the internal terminal 342 via the bonding wire BW.

[0114] In this way, since the vibration element 1 and the circuit element 16 are electrically connected via the internal terminal 341, internal wiring (not shown), internal terminal 342, and bonding wire BW, when the circuit element 16 applies a drive signal to the vibration element 1, the vibration element 1 can be oscillated at a desired frequency.

[0115] As described above, according to the present embodiment, the same effects as those of the above-described Embodiment 1 can be obtained, and the vibration device 10 in which a change in frequency hardly occurs can be provided.

[0116] 5. Embodiment 5 Next, the vibration element 1c according to Embodiment 5 will be described with reference to FIGS. 23 to 25. The vibration element 1c of Embodiment 5 is the same as that of Embodiment 1 except that it is a gyro element having a structure called a so-called double T-type as compared with the vibration element 1 of Embodiment 1. Note that the same components as those in the above-described Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 23 shows a state after the above-described frequency adjustment process is completed, that is, a state in which the laser beam LB is irradiated and a part of the first weight 461 is removed.

[0117] The vibration element 1c of this embodiment is a gyro element, specifically, an angular velocity sensor element capable of detecting an angular velocity ωz with the Z-axis as the detection axis.

[0118] As shown in FIG. 23, the vibration element 1c includes a vibrating body 41c, electrodes 45, and a metal film 46 for adjusting the frequency of the vibrating body 41. In this embodiment, as will be described later, the electrodes 45 are used to vibrate the driving arms 456, 457, 458, 459 of the vibrating body 41c and to detect the vibrations of the detection arms 452, 453 of the vibrating body 41c.

[0119] The vibrating body 41c is formed from a Z-cut quartz plate and has a base portion 451 located at the center, a pair of detection arms 452, 453 as vibrating arms extending from the base portion 451 to the +Y direction side and the -Y direction side respectively, a pair of connecting arms 454, 455 extending from the base portion 451 to the +X direction side and the -X direction side respectively, a pair of driving arms 456, 457 as vibrating arms extending from the tip of the connecting arm 454 to the +Y direction side and the -Y direction side respectively, and a pair of driving arms 458, 459 as vibrating arms extending from the tip of the connecting arm 455 to the +Y direction side and the -Y direction side respectively.

[0120] In this embodiment, the side surfaces on the +X direction side of the detection arm 452, the driving arm 456, and the driving arm 458 extending to the +Y direction side are defined as the first side surfaces 111, and the side surfaces on the -X direction side are defined as the second side surfaces 112. The side surfaces on the +Y direction side, which are the tip surfaces of the detection arm 452, the driving arm 456, and the driving arm 458, are defined as the third side surfaces 113.

[0121] Also, the side surfaces on the -X direction side of the detection arm 453, the driving arm 457, and the driving arm 459 extending to the -Y direction side are defined as the first side surfaces 111, and the side surfaces on the +X direction side are defined as the second side surfaces 112. The side surfaces on the -Y direction side, which are the tip surfaces of the detection arm 453, the driving arm 457, and the driving arm 459, are defined as the third side surfaces 113.

[0122] A pair of detection arms 452 and 453 as vibrating arms each have an arm portion 452a, 453a and a weight portion 452b, 453b. The weight portions 452b and 453b are disposed at the tip portions of the detection arms 452 and 453 on the side opposite to the base portion 451. The arm portions 452a and 453a are disposed closer to the base portion 451 than the weight portions 452b and 453b, and connect the weight portions 452b and 453b to the base portion 451.

[0123] A pair of drive arms 456 and 457 as vibrating arms each have an arm portion 456a, 457a and a weight portion 456b, 457b. The weight portions 456b and 457b are disposed at the tip portions of the drive arms 456 and 457 on the side opposite to the connecting arm 454. The arm portions 456a and 457a are disposed closer to the connecting arm 454 than the weight portions 456b and 457b, and connect the weight portions 456b and 457b to the connecting arm 454.

[0124] A pair of drive arms 458 and 459 as vibrating arms each have an arm portion 458a, 459a and a weight portion 458b, 459b. The weight portions 458b and 459b are disposed at the tip portions of the drive arms 458 and 459 on the side opposite to the connecting arm 455. The arm portions 458a and 459a are disposed closer to the connecting arm 455 than the weight portions 458b and 459b, and connect the weight portions 458b and 459b to the connecting arm 455.

[0125] The weight portions 456b, 457b, 458b, 459b, 452b, and 453b disposed at the tip portions of the drive arms 456, 457, 458, 459 and the detection arms 452, 453 have the same configuration as in the above-described Embodiment 1.

[0126] Specifically, a metal film 46 is disposed on the second surface 102, the first side surface 111, the second side surface 112, and the third side surface 113 of each of the weight portions 456b, 457b, 458b, 459b, 452b, and 453b. The metal film 46 disposed on the second surface 102 is the first weight 461. The removal region 462 on the second surface 102 is a region where the first weight 461 is removed by irradiation with the laser beam LB in the above-described frequency adjustment step.

[0127] When viewed from the Z direction, the first weight 461 in each of the weights 456b, 457b, 458b, 459b, 452b, and 453b is arranged such that the outer edge portion 463A on the first side surface 111 side of the first weight 461 is at the same position as the innermost portion 131 in the first side surface portion and the second side surface portion of the first side surface 111. Further, when viewed from the Z direction, the first weight 461 is arranged such that the outer edge portion 463B on the second side surface 112 side of the first weight 461 is at the same position as the innermost portion 132 in the first side surface portion and the second side surface portion of the second side surface 112. Further, when viewed from the Z direction, the first weight 461 is arranged such that the outer edge portion 463C on the third side surface 113 side of the first weight 461 is inside the innermost portion 133 in the first side surface portion and the second side surface portion of the third side surface 113. Thereby, when irradiating the first weight 461 with the laser beam LB, refraction or shielding of the laser beam LB by the first side surface 111, the second side surface 112, and the third side surface 113 in each of the weights 456b, 457b, 458b, 459b, 452b, and 453b can be suppressed. For this reason, the laser beam LB can be sufficiently irradiated to the first weight 461, generation of foreign matters such as burrs can be suppressed, and a vibration element 1c in which a change in frequency hardly occurs can be provided.

[0128] The electrode 45 includes a drive signal electrode 483, a drive ground electrode 484, a first detection signal electrode 485, a first detection ground electrode 486, a second detection signal electrode 487, and a second detection ground electrode 488. The drive signal electrode 483 is disposed on the first surface 101 and the second surface 102 of the arm portion 456a of the drive arm 456, the first surface 101 and the second surface 102 of the arm portion 457a of the drive arm 457, the first side surface 111 and the second side surface 112 of the arm portion 458a of the drive arm 458, and the first side surface 111 and the second side surface 112 of the arm portion 459a of the drive arm 459.

[0129] The drive ground electrode 484 is disposed on the first side surface 111 and the second side surface 112 of the arm portion 456a of the drive arm 456, on the first side surface 111 and the second side surface 112 of the arm portion 457a of the drive arm 457, on the first surface 101 and the second surface 102 of the arm portion 458a of the drive arm 458, and on the first surface 101 and the second surface 102 of the arm portion 459a of the drive arm 459.

[0130] The first detection signal electrode 485 is disposed on the first surface 101 and the second surface 102 of the arm portion 452a of the detection arm 452, and the first detection ground electrode 486 is disposed on the first side surface 111 and the second side surface 112 of the arm portion 452a of the detection arm 452.

[0131] The second detection signal electrode 487 is disposed on the first surface 101 and the second surface 102 of the arm portion 453a of the detection arm 453, and the second detection ground electrode 488 is disposed on the first side surface 111 and the second side surface 112 of the arm portion 453a of the detection arm 453.

[0132] Such a vibration element 1c detects the angular velocity ωz as follows. As shown in FIG. 24, first, when a drive signal is applied between the drive signal electrode 483 and the drive ground electrode 484, the drive arms 456, 457, 458, 459 bend and vibrate as indicated by the arrows in FIG. 24. Hereinafter, this drive mode is referred to as the drive vibration mode.

[0133] Then, as shown in Fig. 25, when an angular velocity ωz is applied to the vibration element 1c while the vibration element 1c is being driven in the driving vibration mode, a detection vibration mode is newly excited. In the detection vibration mode, a Coriolis force acts on the driving arms 456, 457, 458, 459, and vibration in the direction indicated by the arrow b in Fig. 25 is excited. Then, in response to the vibration in the direction indicated by the arrow b in the driving arms 456, 457, 458, 459, detection vibration due to bending vibration in the direction indicated by the arrow a occurs in the detection arms 452, 453. The charge generated in the detection arm 452 by such a detection vibration mode is taken out as a first detection signal from between the first detection signal electrode 485 and the first detection ground electrode 486, and the charge generated in the detection arm 453 is taken out as a second detection signal from between the second detection signal electrode 487 and the second detection ground electrode 488. Based on these first and second detection signals, the angular velocity ωz can be detected.

[0134] Also, according to the above-described Embodiment 5, the same effects as those of the above-described Embodiment 1 can be obtained. That is, the vibration element according to the present invention can also be applied to a gyro element.

Explanation of Reference Numerals

[0135] 1, 1a, 1b, 1c... vibration element, 10... vibration device, 13... package, 41, 41c... vibrating body, 42... base, 43, 44... vibration arms, 45... electrode, 46... metal film, 101... first surface, 102... second surface, 111, 111a... first side surface, 112, 112a... second side surface, 113, 113a... third side surface, 121, 121a, 123, 125... upper side portions, 122, 122a, 124, 126... lower side portions, 131, 131a, 132, 133... innermost portions, 430, 440... arm portions, 431, 431a, 441, 441a... weight portions, 432, 433, 442, 443... recesses, 461... first weight, 462... removal region, 463A, 463B, 463C... outer edge portions, 481... signal electrode, 482... ground electrode.

Claims

1. a base, a first surface, a second surface facing the first surface in a direction along the Z-axis, a first side surface, a second side surface facing the first side surface in a direction along the X-axis orthogonal to the Z-axis, and a third side surface located on the side opposite to the base, and a vibrating arm extending from the base in a direction along the Y-axis orthogonal to the Z-axis and the X-axis, a first weight disposed on the second surface, the third side surface includes a first side surface portion inclined with respect to the direction along the Z-axis, and a second side surface portion inclined toward the first surface or the second surface with respect to the first side surface portion, the first weight is arranged such that, when viewed from the direction along the Z-axis, an outer edge portion of the first weight on the third side surface side is closer to the base side than the innermost portions of the first side surface portion and the second side surface portion, a vibration element.

2. at least one of the first side surface and the second side surface has the first side surface portion and the second side surface portion, the vibration element according to Claim 1.

3. The first side surface and the second side surface have the first side surface portion and the second side surface portion, the first side surface portion of the first side surface and the first side surface portion of the second side surface are connected to the second surface, when viewed from the direction along the Z-axis, an outer edge portion of the first weight on the first side surface side is at the same position as the innermost portions of the first side surface portion and the second side surface portion on the first side surface, and an outer edge portion of the first weight on the second side surface side is at the same position as the innermost portions of the first side surface portion and the second side surface portion on the second side surface, the vibration element according to Claim 1.

4. the vibrating arm has a weight portion on which the first weight is disposed, and an arm portion having recesses formed in the first surface and the second surface on the base side of the weight portion, a width of the weight portion on the second surface in the direction along the X-axis is smaller than a width of the weight portion on the first surface in the direction along the X-axis, the vibration element according to any one of Claims 1 to 3.

5. a width of the arm portion on the first surface in the direction along the X-axis is equal to a width of the arm portion on the second surface in the direction along the X-axis, the vibration element according to Claim 4.

6. a second weight is disposed on the first side surface portion, the vibration element according to any one of Claims 1 to 5.

7. the vibration element according to any one of Claims 1 to 6, and A vibration device having a package for housing the vibration element.

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