Vibration element and vibration device

Abstract

To provide a vibration element and a vibration device that can prevent a deterioration in vibration characteristics.SOLUTION: A vibration element comprises a vibration part 110, a support part 120, and a connection part 130, and also comprises: a first excitation electrode 21 that is provided on a first principal face 101; a second excitation electrode 22 that is provided on a second principal face 102 and excites thickness slip vibration displaced along an X-direction with the first excitation electrode 21; a first support electrode 23 that is provided on the support part 120 and electrically connected with the first excitation electrode 21; a second support electrode 24 that is provided on the support part 120 and electrically connected with the second excitation electrode 22; a first lead-out wire 21a that is led out from the first excitation electrode 21 along a Z-direction and electrically connects the first excitation electrode 21 and the first support electrode 23 to each other; and a second lead-out wire 22a that is led out from the second excitation electrode 22 along the Z-direction and electrically connects the second excitation electrode 22 and the second support electrode 24 to each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vibration element and a vibration device. [Background Art]

[0002] Patent Document 1 discloses a piezoelectric vibrating piece including: a vibration portion provided with a pair of excitation electrodes; a support portion extending apart from the vibration portion; and a connection portion extending to connect one end of the support portion and an end of the vibration portion, wherein lead-out wirings are respectively drawn from the pair of excitation electrodes to a bonding surface of the support portion, thereby suppressing the influence of support stress on vibration. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2015-186196 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in the technology described in Patent Document 1, the lead-out wirings are drawn out from the vibration portion in the X direction, which is the direction in which thickness-shear vibration occurs, so the lead-out wirings are affected by the vibration, which may deteriorate vibration characteristics. [Means for Solving the Problem]

[0005] The vibrating element comprises: a vibrating portion having a first main surface, a second main surface facing the first main surface, a first side surface connecting the first and second main surfaces and extending along a first direction, and a second side surface connecting the first and second main surfaces and extending along a second direction intersecting the first direction; a support portion disposed spaced apart from the vibrating portion and facing the first side surface of the vibrating portion, having a first support side surface extending along a first direction and a second support side surface extending along a second direction; and a connecting portion having a first connecting surface connected to the first side surface and the first support surface, and a second connecting surface connected to the second side surface and the second support surface. The device comprises: a first excitation electrode provided on the first main surface; a second excitation electrode provided on the second main surface for exciting a thickness sliding vibration displaced along the second direction together with the first excitation electrode; a first support electrode provided on the support portion and electrically connected to the first excitation electrode; a second support electrode provided on the support portion and electrically connected to the second excitation electrode; a first lead wire drawn out from the first excitation electrode along the first direction and electrically connecting the first excitation electrode and the first support electrode; and a second lead wire drawn out from the second excitation electrode along the first direction and electrically connecting the second excitation electrode and the second support electrode.

[0006] The vibration device comprises the vibration element described above, a base on which the vibration element is mounted, and a container for housing the vibration element, wherein the support portion of the vibration element is joined to the base via a bonding material. [Brief explanation of the drawing]

[0007] [Figure 1] A plan view showing the configuration of the vibration device. [Figure 2] A cross-sectional view of the vibration device shown in Figure 1, along line AA. [Figure 3] A plan view showing the configuration of the vibrating element. [Figure 4] A cross-sectional view of the vibrating element along the BB line shown in Figure 3. [Figure 5] A plan view showing the configuration of a modified vibration element. [Figure 6A] A plan view showing the configuration of a modified vibration element. [Figure 6B] Figure 6A is a side view showing the configuration of the vibrating element. [Figure 6C] Figure 6A is a side view showing the configuration of the vibrating element. [Figure 7A] A plan view showing the configuration of a modified vibration element. [Figure 7B] A side view showing the configuration of the vibrating element in Figure 7A. [Figure 7C] A side view showing the configuration of the vibrating element in Figure 7A. [Figure 8A] A plan view showing the configuration of a modified vibration element. [Figure 8B] Figure 8A is a side view showing the configuration of the vibrating element. [Modes for carrying out the invention]

[0008] In the following diagrams, the three mutually orthogonal axes are referred to as the X-axis, Y-axis, and Z-axis. The direction along the X-axis is called the "X-direction," the direction along the Y-axis is called the "Y-direction," and the direction along the Z-axis is called the "Z-direction." The direction of the arrow is the + direction, and the direction opposite to the + direction is called the - direction.

[0009] First, the configuration of the vibration device 100 will be explained with reference to Figures 1 and 2. Note that, for the sake of clarity, the lid 47 is omitted from Figure 1.

[0010] As shown in Figures 1 and 2, the vibration device 100 comprises a vibration element 1, a container 40 made of ceramic or the like that houses the vibration element 1, and a lid 47 made of glass, ceramic, or metal or the like.

[0011] As shown in Figure 2, the container 40 is formed by stacking mounting terminals 44, a first substrate 41, a second substrate 42, and a third substrate 43. In this embodiment, the second substrate 42 is the base on which the vibrating piece 10, i.e., the vibrating element 1, is mounted.

[0012] The container 40 has a cavity 48 that opens upward. The interior of the cavity 48 that houses the vibration element 1 is hermetically sealed into a reduced-pressure atmosphere or an inert gas atmosphere such as nitrogen by joining a lid 47 with a joining member 50 such as a seal ring.

[0013] A plurality of mounting terminals 44 are provided on the outer bottom surface of the first substrate 41. The mounting terminals 44 are electrically connected to connection terminals 45 provided above the second substrate 42 via through electrodes or interlayer wirings not shown in the figures.

[0014] The vibration element 1 is housed inside the cavity 48 of the container 40. In the vibration element 1, support electrodes 23 and 24 provided on a support portion 120 (see FIG. 3) are respectively joined to connection terminals 45 provided on a mounting surface 46 of the second substrate 42 serving as a base via a joining material 51 such as a conductive adhesive, and are thus electrically connected.

[0015] The joining material 51 includes a first conductive adhesive and a second conductive adhesive. The first conductive adhesive electrically connects the first excitation electrode 21 to the second substrate 42. The second conductive adhesive electrically connects the second excitation electrode 22 to the second substrate 42. That is, the excitation electrodes 21 and 22 of the vibration element 1 and the mounting terminals 44 provided on the container 40 are respectively electrically connected to each other via the support electrodes 23 and 24, the joining material 51, the connection terminals 45, and the like.

[0016] Next, the configuration of the vibration element 1 will be described with reference to FIG. 3 and FIG. 4.

[0017] As shown in FIG. 3 and FIG. 4, the vibration element 1 includes a vibrating piece 10, a first excitation electrode 21, a second excitation electrode 22, a first support electrode 23, and a second support electrode 24.

[0018] The vibrating element 10 is capable of thickness-sliding vibration and is made of various piezoelectric materials, including quartz crystals. Typically, it is an AT-cut quartz crystal or a quartz crystal with a double rotation cut, such as an SC-cut crystal. In this embodiment, the vibrating element 10 has a square planar shape, specifically a rectangular AT-cut quartz crystal. Therefore, the positive directions of the X, Y, and Z axes in the figure coincide with the positive directions of the X, Y', and Z' axes of the quartz crystal, respectively. However, this is not necessarily the case, and at least one of the axes may coincide with the negative direction.

[0019] The vibrating piece 10 is a rectangular flat plate with the X direction as the longitudinal direction and the Z direction as the width direction. The vibrating piece 10 has a vibrating part 110, a support part 120 positioned spaced apart from the vibrating part 110, and a connecting part 130 that connects the vibrating part 110 and the support part 120.

[0020] The vibrating section 110 has a first main surface 101, a second main surface 102 which is in a front-back relationship with the first main surface 101, a first side surface 103 which connects the first main surface 101 and the second main surface 102 and extends along the first direction, the Z direction, and a second side surface 104 which connects the first main surface 101 and the second main surface 102 and extends along the second direction, the X direction which intersects the Z direction.

[0021] The support portion 120 is positioned opposite the first side surface 103 of the vibrating portion 110 and has a first support side surface 121 extending along the Z direction and a second support side surface 122 extending along the X direction.

[0022] The connecting portion 130 has a first connecting surface 131 connected to the first side surface 103 and the first support side surface 121, and a second connecting surface 132 connected to the second side surface 104 and the second support side surface 122.

[0023] A first excitation electrode 21 is provided approximately in the center of the first main surface 101 of the vibrating piece 10. A second excitation electrode 22 is provided approximately in the center of the second main surface 102 of the vibrating piece 10 so as to overlap with the first excitation electrode 21 in a plan view. Specifically, the second excitation electrode 22 excites a thickness-sliding vibration that displaces along the X direction together with the first excitation electrode 21.

[0024] The first excitation electrode 21 is electrically connected to the first support electrode 23 via the first lead wiring 21a. The second excitation electrode 22 is electrically connected to the second support electrode 24 via the second lead wiring 22a. The first support electrode 23 is electrically connected to the first lead wiring 21a via, for example, a through electrode provided through the vibrating piece 10.

[0025] The first support electrode 23 is provided on the support portion 120 and is electrically connected to the first excitation electrode 21. The second support electrode 24 is provided on the support portion 120 and is electrically connected to the second excitation electrode 22.

[0026] The first lead wire 21a is drawn out from the first excitation electrode 21 along the Z direction and electrically connects the first excitation electrode 21 and the first support electrode 23. Specifically, the first lead wire 21a is drawn out from the first excitation electrode 21 toward the second side surface 104 in the -Z direction.

[0027] The second lead wire 22a is drawn out from the second excitation electrode 22 along the Z direction and electrically connects the second excitation electrode 22 and the second support electrode 24. Specifically, the second lead wire 22a is drawn out from the second excitation electrode 22 toward the second side surface 104 in the -Z direction.

[0028] Thus, the first lead wire 21a is led out from the first excitation electrode 21 in the -Z direction and then electrically connected to the first support electrode 23, and the second lead wire 22a is led out from the second excitation electrode 22 in the -Z direction and then electrically connected to the second support electrode 24. This makes it possible to suppress the effect of thickness-sliding vibrations generated in the X direction on the lead wires 21a and 22a, and thus suppress the deterioration of vibration characteristics. Examples of vibration characteristics include the Q value (ease of vibration) and the CI (Crystal Impedance) value (i.e., the resistance value of the vibration element 1).

[0029] Furthermore, since the first lead wire 21a and the second lead wire 22a are led out to the second side surface 104, the length of the lead wires 21a and 22a from each excitation electrode 21 and 22 to the support electrodes 23 and 24 can be shortened, and the wiring resistance of the lead wires 21a and 22a can be reduced.

[0030] As described above, the vibration element 1 of this embodiment has a vibration section 110 having a first main surface 101, a second main surface 102 which is in a front-back relationship with the first main surface 101, a first side surface 103 which connects the first main surface 101 and the second main surface 102 and extends along the Z direction, and a second side surface 104 which connects the first main surface 101 and the second main surface 102 and extends along the X direction which intersects the Z direction; a support section 120 which is spaced apart from the vibration section 110, is positioned opposite the first side surface 103 of the vibration section 110 and has a first support side surface 121 which extends along the Z direction and a second support side surface 122 which extends along the X direction; a first connecting surface 131 which is connected to the first side surface 103 and the first support side surface 121, and connected to the second side surface 104 and the second support side surface 122 The device comprises a connecting portion 130 having a second connecting surface 132, a first excitation electrode 21 provided on the first main surface 101, a second excitation electrode 22 provided on the second main surface 102 which excites a thickness sliding vibration displaced along the X direction together with the first excitation electrode 21, a first support electrode 23 provided on the support portion 120 and electrically connected to the first excitation electrode 21, a second support electrode 24 provided on the support portion 120 and electrically connected to the second excitation electrode 22, a first lead wire 21a drawn out from the first excitation electrode 21 along the -Z direction and electrically connecting the first excitation electrode 21 and the first support electrode 23, and a second lead wire 22a drawn out from the second excitation electrode 22 along the -Z direction and electrically connecting the second excitation electrode 22 and the second support electrode 24.

[0031] With this configuration, the first lead wire 21a is led out from the first excitation electrode 21 in the -Z direction and then electrically connected to the first support electrode 23, and the second lead wire 22a is led out from the second excitation electrode 22 in the -Z direction and then electrically connected to the second support electrode 24. This makes it possible to suppress the effect of thickness-sliding vibrations generated in the X direction on the lead wires 21a and 22a, thereby suppressing the deterioration of vibration characteristics.

[0032] Furthermore, in the vibration element 1 of this embodiment, it is preferable that the first lead wire 21a is led out from the first excitation electrode 21 toward the second side surface 104, and the second lead wire 22a is led out from the second excitation electrode 22 toward the second side surface 104. With this configuration, it is possible to shorten the length of the lead wires 21a, 22a from each excitation electrode 21, 22 to the support electrodes 23, 24, and the wiring resistance of the lead wires 21a, 22a can be reduced.

[0033] As described above, the vibration device 100 of this embodiment comprises the vibration element 1 described above, a second substrate 42 on which the vibration element 1 is mounted, and a container 40 for housing the vibration element 1. The support portion 120 of the vibration element 1 is joined to the second substrate 42 via a bonding material 51. This configuration makes it possible to provide a vibration device 100 in which the influence of vibration characteristics is suppressed.

[0034] Furthermore, in the vibration device 100 of this embodiment, it is preferable that the bonding material 51 includes a first conductive adhesive that electrically connects the first excitation electrode 21 provided on the first main surface 101 and the second substrate 42, and a second conductive adhesive that electrically connects the second excitation electrode 22 provided on the second main surface 102 and the second substrate 42. With this configuration, since the bonding material 51 includes the first conductive adhesive and the second conductive adhesive, electrical transmission and reception can be performed between the first excitation electrode 21 and the second excitation electrode 22 and the outside.

[0035] The following describes some variations of the embodiments described above.

[0036] As described above, the method of drawing out the first lead wire 21a from the first excitation electrode 21 and the method of drawing out the second lead wire 22a from the second excitation electrode 22 are not limited to the above embodiment, but may be as shown in Figures 5 to 8B.

[0037] In the modified example shown in Figure 5, the first lead wire 21a of the vibrating element 1A is led out in the +Z direction from the first excitation electrode 21 and routed along the edges of the third side surface 105, the first side surface 103, the first connecting surface 131, and the first support side surface 121, electrically connecting the first excitation electrode 21 and the first support electrode 23. On the other hand, the second lead wire 22a is arranged in the same manner as in the above embodiment.

[0038] In this configuration, it is preferable that the first lead wire 21a is led out from the first excitation electrode 21 toward the third side surface 105, which is the opposite side of the second side surface 104, and the second lead wire 22a is led out from the second excitation electrode 22 toward the second side surface 104. With this configuration, since the first lead wire 21a and the second lead wire 22a are led out in opposite directions, it is possible to increase the distance between the first lead wire 21a and the second lead wire 22a, thereby suppressing the formation of parasitic capacitance.

[0039] Alternatively, the first lead wire 21a may be routed toward the second side surface 104, and the second lead wire 22a may be routed toward the third side surface 105.

[0040] Furthermore, the first lead wire 21a of the modified vibration element 1B shown in Figures 6A, 6B, and 6C is led out in the +Z direction from the first excitation electrode 21 and routed to the side surfaces, namely the third side surface 105, the first side surface 103, the first connecting surface 131, and the first support side surface 121, thereby electrically connecting the first excitation electrode 21 and the first support electrode 23. On the other hand, the second lead wire 22a is led out in the -Z direction from the second excitation electrode 22 and routed to the side surfaces, namely the second side surface 104, the second connecting surface 132, and the second support side surface 122, thereby electrically connecting the second excitation electrode 22 and the second support electrode 24.

[0041] Thus, it is preferable that the first lead wiring 21a is provided across the third side surface 105, and the second lead wiring 22a is provided across the second side surface 104. With this configuration, the lead wirings 21a and 22a are formed on the second side surface 104 and the third side surface 105, and the lead wirings 21a and 22a are arranged on surfaces different from the surface on which the first excitation electrode 21 and the second excitation electrode 22 are located, so that vibrations generated on the surface do not affect the lead wirings 21a and 22a.

[0042] Alternatively, the first lead-out wiring 21a may be led to the second side surface 104, and the second lead-out wiring 22a may be led to the third side surface 105, the first side surface 103, the first connecting surface 131, and the first support side surface 121.

[0043] Furthermore, the first lead wire 21a of the modified vibrating element 1C shown in Figures 7A, 7B, and 7C is led out in the +Z direction from the first excitation electrode 21 and routed along both the surface and the side of the third side surface 105, the first side surface 103, the first connecting surface 131, and the first support side surface 121, electrically connecting the first excitation electrode 21 and the first support electrode 23. On the other hand, the second lead wire 22a is led out in the -Z direction from the second excitation electrode 22 and routed along both the surface and the side of the second side surface 104, the second connecting surface 132, and the second support side surface 122, electrically connecting the second excitation electrode 22 and the second support electrode 24.

[0044] In this way, by arranging the lead wires 21a and 22a on the first main surface 101 and the second main surface 102 and the side surface, the area of ​​the lead wires 21a and 22a is increased, which reduces the wiring resistance and lowers the CI value.

[0045] Furthermore, the first lead wire 21a of the modified vibration element 1D shown in Figures 8A and 8B is arranged in the same manner as in the above embodiment. On the other hand, the second lead wire 22a is led out from the second excitation electrode 22 in the -Z direction and routed to the side surfaces, namely the second side surface 104, the second connecting surface 132, and the second support side surface 122, thereby electrically connecting the second excitation electrode 22 and the second support electrode 24.

[0046] Thus, it is preferable that the second lead-out wiring 22a is provided across the second side surface 104. With this configuration, since the second lead-out wiring 22a, which is one of the first lead-out wiring 21a and the second lead-out wiring 22a, is arranged on the second side surface 104, the influence of vibrations generated on the second main surface 102 can be suppressed. Alternatively, the first lead-out wiring 21a may be led to the second side surface 104, and the second lead-out wiring 22a may be arranged in the same manner as in the above embodiment.

[0047] Furthermore, the first lead wiring 21a and the second lead wiring 22a each include a base layer made of chromium and an electrode layer made of gold, with the thickness of the base layer preferably being 1 nm or more and 5 nm or less, and the thickness of the electrode layer preferably being 100 nm or more and 500 nm or less.

[0048] With this configuration, by extending the lead wires 21a and 22a in the Z direction to suppress the effects of thickness-induced sliding vibrations in the X direction, even if the length of the lead wires 21a and 22a increases, the wiring resistance can be reduced by making the underlying layer the thickness described above. Therefore, it is possible to suppress the increase in resistance values ​​such as the CI value. [Explanation of symbols]

[0049] 1, 1A, 1B, 1C, 1D…Vibrating element, 10…Vibrating piece, 21…First excitation electrode, 21a…First lead-out wiring, 22…Second excitation electrode, 22a…Second lead-out wiring, 23…First support electrode, 24…Second support electrode, 40…Container, 41…First substrate, 42…Second substrate as base, 43…Third substrate, 44…Mounting terminals, 45…Connection terminals, 46…Mounting surface, 47… Lid, 48...Cavity, 50...Jointing member, 51...Jointing material, 100...Vibration device, 101...First main surface, 102...Second main surface, 103...First side surface, 104...Second side surface, 105...Third side surface, 110...Vibrating part, 120...Support part, 121...First support side surface, 122...Second support side surface, 130...Connecting part, 131...First connecting surface, 132...Second connecting surface.

Claims

1. A vibrating part having a first main surface, a second main surface that is in a front-back relationship with the first main surface, a first side surface that connects the first main surface and the second main surface and extends along a first direction, and a second side surface that connects the first main surface and the second main surface and extends along a second direction that intersects the first direction, A support portion having a first support surface that is spaced apart from the vibrating portion, facing the first side surface of the vibrating portion, and extending along the first direction, and a second support surface that extends along the second direction, A connecting portion having a first connecting surface connected to the first side surface and the first support side surface, and a second connecting surface connected to the second side surface and the second support side surface, Equipped with, The first excitation electrode provided on the first main surface, A second excitation electrode is provided on the second main surface and excites a thickness sliding vibration that displaces along the second direction together with the first excitation electrode, A first support electrode is provided on the support portion and is electrically connected to the first excitation electrode, A second support electrode is provided in the support portion and is electrically connected to the second excitation electrode, In a plan view, a first lead wire extends from the first excitation electrode toward the third side surface, which is the side opposite to the second side surface, and is arranged along the third side surface, the first side surface, the first connecting surface, and the first support side surface, electrically connecting the first excitation electrode and the first support electrode. In a plan view, a second lead wire extends from the second excitation electrode toward the second side surface and is arranged along the second side surface, the second connecting surface, and the second support side surface, electrically connecting the second excitation electrode and the second support electrode, A vibrating element equipped with the following features.

2. A vibrating element according to claim 1, The first lead-out wiring is provided across the third side surface, The second lead-out wiring is a vibrating element provided across the second side surface.

3. The vibrating element according to Claim 2, The first lead-out wiring is provided across the first side surface, the first connecting surface, and the first support side surface. The second lead-out wiring is a vibrating element provided across the second connecting surface and the second support side surface.

4. A vibrating element according to claim 1, The first lead wiring and the second lead wiring each include a base layer made of chromium and an electrode layer made of gold, The thickness of the aforementioned underlayer is 1 nm or more and 5 nm or less. A vibrating element having an electrode layer thickness of 100 nm or more and 500 nm or less.

5. A vibrating element according to any one of claims 1 to 4, The base on which the vibration element is mounted, A container for housing the vibrating element, Equipped with, A vibration device in which the support portion of the vibration element is joined to the base via a bonding material.

6. A vibration device according to claim 5, The bonding material includes a first conductive adhesive that electrically connects the first excitation electrode provided on the first main surface to the base, and a second conductive adhesive that electrically connects the second excitation electrode provided on the second main surface to the base, in a vibration device.

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