Vibration device, vibration module, electronic device and mobile object

Abstract

To provide a vibration device that has excellent vibration characteristics, a vibration module, an electronic apparatus, and a movable body.SOLUTION: A vibration device has a vibration element, a relay substrate, a base, an element-side joint member that joins the vibration element and the relay substrate to each other, and a base-side joint member that joins the base and the relay substrate to each other. The element-side joint member has a first joint member and a second joint member that are arranged side by side along an A axis. An X axis of a first crystal substrate of the vibration element is along the A axis, and a second crystal substrate of the relay substrate is a z-cut crystal substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration device, a vibration module, an electronic device, and a moving object. [Background technology]

[0002] The piezoelectric vibrating device described in Patent Document 1 has a base made of ceramics, a piezoelectric vibrating piece made of an AT-cut quartz crystal substrate, and a support material made of a Z-cut quartz crystal substrate. The piezoelectric vibrating piece is supported on the base via the support material. A pair of first metal bumps is disposed between the base and the support material, and the base and the support material are mechanically and electrically connected by the pair of first metal bumps. A pair of second metal bumps is disposed between the support material and the piezoelectric vibrating piece, and the support material and the piezoelectric vibrating piece are mechanically and electrically connected by the pair of second metal bumps.

[0003] In addition, in Fig. 1 of Patent Document 1, the X-axis is drawn along the longitudinal direction of the piezoelectric vibrating reed, but there is no description of the X-axis in the detailed description of the specification. Therefore, it is unclear whether this X-axis represents the electrical axis of the AT-cut quartz crystal substrate that constitutes the piezoelectric vibrating reed, or simply represents a three-dimensional coordinate system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-166884 A Summary of the Invention [Problem to be solved by the invention]

[0005] In such a piezoelectric vibrating device of Patent Document 1, a support material is interposed between the base and the piezoelectric vibrating piece. Therefore, there are many interfaces between members with different linear expansion coefficients, such as between the base and the first metal bump, between the first metal bump and the support member, between the support member and the second metal bump, and between the second metal bump and the piezoelectric vibrating piece. As such, when the number of interfaces between members with different linear expansion coefficients increases, the stress applied to the piezoelectric vibrating piece increases due to the difference between the linear expansion coefficients, and the deformation of the piezoelectric vibrating piece increases, resulting in a problem of deteriorating frequency accuracy. [Means for solving the problem]

[0006] The vibration device according to the present invention includes a vibration element including a first quartz crystal substrate having a first surface and a second surface that are in a front-back relationship with each other and aligned along an X-axis that is an electrical axis, a first excitation electrode arranged on the first surface, a second excitation electrode arranged on the second surface so as to face the first excitation electrode, and a first terminal arranged on the first surface and electrically connected to the first excitation electrode and a second terminal arranged on the first surface and electrically connected to the second excitation electrode; A base including a substrate located on the first surface side of the vibration element, and a first substrate wiring and a second substrate wiring arranged on the substrate; a relay substrate including a second quartz crystal substrate disposed between the vibration element and the base, the thickness direction of which is along the Z-axis which is the optical axis; a first relay wiring and a second relay wiring disposed on a third surface of the second quartz crystal substrate on the vibration element side; a third relay wiring electrically connected to the first relay wiring and a fourth relay wiring electrically connected to the second relay wiring, which are reverse to the third surface and disposed on a fourth surface of the base side; an element-side bonding member that includes a first bonding member that electrically connects the first terminal and the first relay wiring and a second bonding member that electrically connects the second terminal and the second relay wiring, and that bonds the vibration element to the relay substrate; a third bonding member electrically connecting the first substrate wiring and the third relay wiring and a fourth bonding member electrically connecting the second substrate wiring and the fourth relay wiring, and a base side bonding member bonding the base and the relay substrate; The first joint member and the second joint member are arranged side by side in a direction along the X-axis.

[0007] A vibration module according to the present invention includes the vibration device described above.

[0008] An electronic device according to the present invention includes the above-mentioned vibration device, and a processing circuit that operates based on a signal output from the vibration device.

[0009] A moving object according to the present invention includes the above-mentioned vibration device and and a processing circuit that operates based on a signal output from the vibration device. [Brief description of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of a vibration device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the vibration device in FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line WW in FIG. [Diagram 5] FIG. [Figure 6] FIG. 1 is a diagram showing the cut angle of an AT cut. [Figure 7] FIG. 2 is a plan view showing a vibration element. [Figure 8] FIG. 13 is a plan view showing a modified example of the relay substrate. [Figure 9] FIG. 13 is a plan view showing a modified example of the relay substrate. [Figure 10] 11 is a cross-sectional view showing a state in which the relay substrate is curved and deformed. FIG. [Figure 11] FIG. 13 is a plan view showing a modified example of the relay substrate. [Figure 12] FIG. 4 is a plan view showing a vibration device according to a second embodiment of the present invention. [Figure 13] 13 is a graph showing the amount of displacement of a vibrating section. [Figure 14] FIG. 11 is a plan view showing a vibration device according to a third embodiment of the present invention. [Figure 15] 11 is a cross-sectional view showing a vibration element of a vibration device according to a fourth embodiment of the present invention. FIG. [Figure 16] 13 is a cross-sectional view showing a vibration element of a vibration device according to a fifth embodiment of the present invention. FIG. [Figure 17] 13 is a cross-sectional view showing a vibration module according to a sixth embodiment of the present invention. FIG. [Figure 18] FIG. 13 is a perspective view showing a smartphone according to a seventh embodiment. [Figure 19] FIG. 13 is a perspective view showing an automobile according to an eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vibration device, a vibration module, an electronic device, and a moving object according to the present invention will be described below in detail with reference to embodiments shown in the accompanying drawings.

[0012] First Embodiment FIG. 1 is an exploded perspective view of a vibration device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the vibration device in FIG. 1. FIG. 3 is a plan view showing a base. FIG. 4 is a cross-sectional view of the WW line in FIG. 3. FIG. 5 is a plan view showing an intermediate substrate. FIG. 6 is a diagram showing the cut angle of the AT cut. FIG. 7 is a plan view showing a vibration element. FIG. 8 and FIG. 9 are plan views showing modified intermediate substrates. FIG. 10 is a cross-sectional view showing a state in which the intermediate substrate is curved and deformed. FIG. 11 is a plan view showing a modified intermediate substrate. For convenience of explanation, each figure shows an A axis, a B axis, and a C axis that are perpendicular to each other. The tip side of the arrow of each axis is also called the "plus side", and the base end side is also called the "minus side". The plus side of the C axis is also called the "upper side", and the minus side is also called the "lower side". A plan view from a direction along the C axis is also simply called a "plan view".

[0013] As shown in FIG. 1, the vibration device 1 has a base 4, an intermediate substrate 6 bonded to the upper surface of the base 4 via a base-side bonding member 8, a vibration element 5 bonded to the upper surface of the intermediate substrate 6 via an element-side bonding member 9, and a lid 3 bonded to the upper surface of the base 4 via a bonding member 7 so as to cover the intermediate substrate 6 and the vibration element 5. In such a vibration device 1, as shown in FIG. 2, the base 4 and the lid 3 form a storage space S for accommodating the intermediate substrate 6 and the vibration element 5. The storage space S is airtight and in a reduced pressure state, preferably in a state closer to a vacuum. This reduces the CI (crystal impedance) value of the vibration element 5, improving the oscillation characteristics. However, the atmosphere of the storage space S is not particularly limited, and may be, for example, in an atmospheric pressure state or a pressurized state.

[0014] 3 and 4, base 4 has substrate 41, and first substrate wiring 42 and second substrate wiring 43 arranged on substrate 41. Substrate 41 is a thin plate, and has lower surface 411 and upper surface 412 which are opposite surfaces. Substrate 41 has two through holes 413, 414 penetrating lower surface 411 and upper surface 412. Substrate 41 has a rectangular shape in a plan view.

[0015] The substrate 41 is a semiconductor substrate. The semiconductor substrate is not particularly limited, and may be, for example, a silicon substrate, a germanium substrate, or a compound semiconductor substrate such as GaP, GaAs, or InP. By using a semiconductor substrate as the substrate 41, the resonator device 1 can be formed by a semiconductor process. Therefore, the resonator device 1 can be manufactured with high precision and can be made smaller. In addition, the substrate 41 can be doped with impurities such as phosphorus (P) or boron (B) to form a plurality of active elements, and the active elements can be electrically connected to each other, thereby forming a semiconductor circuit, for example, including an oscillator circuit, on the substrate 41. In this way, the space of the substrate 41 can be effectively utilized. In this embodiment, a silicon substrate is used as the substrate 41. This makes the substrate 41 easy to obtain, inexpensive, and easy to process.

[0016] In order to ensure the insulation of the substrate 41, an insulating film 410 is formed on the surface of the substrate 41. The insulating film 410 is made of a silicon oxide film (SiO2 film). The method of forming the insulating film 410 is not particularly limited, and for example, the insulating film 410 may be formed by thermally oxidizing the surface of the substrate 41, or may be formed by plasma CVD using TEOS (tetraethoxysilane). The insulating film 410 is not particularly limited, and may be formed of an insulating resin material such as polyimide, or may be formed of a composite material in which different materials are laminated.

[0017] However, the substrate 41 is not limited to a semiconductor substrate, and may be, for example, a ceramic substrate, a glass substrate, or the like.

[0018] Moreover, the first substrate wiring 42 has an internal terminal 421 arranged on the upper surface 412 and facing the storage space S, an external terminal 422 arranged on the lower surface 411, and a through electrode 423 arranged in the through hole 413 and electrically connecting the internal terminal 421 and the external terminal 422. Similarly, the second substrate wiring 43 has an internal terminal 431 arranged on the upper surface 412 and facing the storage space S, an external terminal 432 arranged on the lower surface 411, and a through electrode 433 arranged in the through hole 414 and electrically connecting the internal terminal 431 and the external terminal 432.

[0019] In this embodiment, two dummy terminals 44, 45 are further arranged on the lower surface 411. The dummy terminals 44, 45 do not play an electrical role and are provided, for example, to increase the bonding strength with the target object. However, the role of the dummy terminals 44, 45 is not limited to this. Also, the dummy terminals 44, 45 may be omitted.

[0020] As shown in FIG. 2, the lid 3 has a bottomed recess 32 that opens to the bottom surface. The lid 3 is bonded to the base 4 with the intermediate substrate 6 and the vibration element 5 housed in the recess 32. The lid 3 is a semiconductor substrate. The semiconductor substrate is not particularly limited, and may be, for example, a silicon substrate, a germanium substrate, or a compound semiconductor substrate such as GaP, GaAs, or InP. By using a semiconductor substrate as the lid 3, the vibration device 1 can be formed by a semiconductor process, and therefore the vibration device 1 can be manufactured with high precision and can be miniaturized.

[0021] In particular, in this embodiment, a silicon substrate is used as the lid 3. This makes the lid 3 easy to obtain, inexpensive, and easy to process. In addition, the materials of the substrate 41 and the lid 3 can be the same, and their thermal expansion coefficients can be made equal. This suppresses the generation of stress caused by thermal expansion and its increase or decrease, resulting in a vibration device 1 with excellent vibration characteristics.

[0022] However, the lid 3 is not particularly limited, and for example, a ceramic substrate, a glass substrate, or the like may be used. Also, a substrate of a different type from the substrate 41 may be used as the lid 3. In particular, when a glass substrate having optical transparency is used as the lid 3, after the vibration device 1 is manufactured, a laser is irradiated onto the vibration element 5 through the lid 3 to remove a part of the excitation electrode, thereby adjusting the frequency of the vibration element 5.

[0023] Such a lid 3 is directly bonded to the base 4 via a bonding member 7. In this embodiment, the lid 3 and the base 4 are bonded to each other by diffusion bonding, which utilizes the diffusion between metals among other direct bonding methods. However, the bonding method is not limited to this, and for example, the bonding surfaces of the lid 3 and the base 4 may be irradiated with an inert gas such as argon gas to activate these bonding surfaces and then directly bonded. Bonding may also be performed using various bonding members such as a resin adhesive or low-melting point glass.

[0024] As shown in FIG. 1 and FIG. 2, the intermediate substrate 6 is disposed above the base 4 at a distance from the base 4. The intermediate substrate 6 also includes a Z-cut second quartz crystal substrate 61 and a pair of wirings 62, 63 disposed on the second quartz crystal substrate 61. To briefly explain the Z-cut second quartz crystal substrate 61, quartz crystal has crystal axes X, Y, and Z that are perpendicular to each other. The X-axis, Y-axis, and Z-axis are called the electrical axis, mechanical axis, and optical axis, respectively. The second quartz crystal substrate 61 is a "Z-cut quartz crystal substrate" cut along the XY plane. That is, the second quartz crystal substrate 61 has a thickness in the Z-axis direction and an extension in the XY plane direction.

[0025] The second quartz crystal substrate 61 is a thin plate, and has a lower surface 611 as a fourth surface and an upper surface 612 as a third surface, which are in a front-back relationship. The shape of the second quartz crystal substrate 61 in a plan view is rectangular. In particular, in this embodiment, the shape is a rectangle with the longer side in the Y-axis direction and the shorter side in the X-axis direction. The second quartz crystal substrate 61 is disposed such that the X-axis direction coincides with the A-axis direction, the Y-axis direction coincides with the B-axis direction, and the Z-axis direction coincides with the C-axis.

[0026] 5, the wiring 62 has a first relay wiring 621 arranged on the upper surface 612, a third relay wiring 622 arranged on the lower surface 611, and a connection wiring 623 passing through a side surface to electrically connect the first relay wiring 621 and the third relay wiring 622. Similarly, the wiring 63 has a second relay wiring 631 arranged on the upper surface 612, a fourth relay wiring 632 arranged on the lower surface 611, and a connection wiring 633 passing through a side surface to electrically connect the second relay wiring 631 and the fourth relay wiring 632.

[0027] The first relay wiring 621 and the second relay wiring 631 arranged on the upper surface 612 are arranged side by side in the A-axis direction. Meanwhile, the third relay wiring 622 and the fourth relay wiring 632 arranged on the lower surface 611 are arranged side by side in the B-axis direction. The configuration of the connection wirings 623, 633 is not particularly limited, and may include, for example, a through electrode that penetrates the second crystal substrate 61.

[0028] The relay board 6 is joined to the upper surface 412 of the base 4 via the base-side joint member 8. The base-side joint member 8 has a third joint member B3 and a fourth joint member B4 arranged to be spaced apart from each other. As shown in FIG. 3 and FIG. 5, the third joint member B3 contacts the internal terminal 421 and the third relay wiring 622, and electrically connects the first board wiring 42 and the wiring 62. Meanwhile, the fourth joint member B4 contacts the internal terminal 431 and the fourth relay wiring 632, and electrically connects the second board wiring 43 and the wiring 63. The third joint member B3 and the fourth joint member B4 are arranged side by side in the B-axis direction.

[0029] 1 and 2, the vibration element 5 is disposed above the intermediate substrate 6 and spaced apart from the intermediate substrate 6. The vibration element 5 also includes an AT-cut first quartz crystal substrate 51 and a pair of electrodes 52, 53 disposed on the first quartz crystal substrate 51. The AT-cut first quartz crystal substrate 51 has a thickness-shear vibration mode and has third-order frequency-temperature characteristics. Therefore, the vibration element 5 has excellent temperature characteristics.

[0030] To briefly explain AT-cut, as mentioned above, quartz has crystal axes X, Y, and Z that are perpendicular to each other. As shown in FIG. 6, the first quartz substrate 51 is a "rotated Y-cut quartz substrate" cut along a plane obtained by rotating the XZ plane by a predetermined angle θ around the X-axis, and a substrate cut along a plane rotated θ=35°15' is called an "AT-cut quartz substrate". In the following, the Y-axis and Z-axis rotated around the X-axis corresponding to the angle θ are referred to as the Y'-axis and Z'-axis. In other words, the first quartz substrate 51 has a thickness in the Y'-axis direction and an extension in the X-Z' plane direction.

[0031] As shown in FIG. 2, the first quartz crystal substrate 51 is a thin plate, and has a lower surface 511 as a first surface and an upper surface 512 as a second surface, which are in a front-back relationship. Also, as shown in FIG. 1 and FIG. 7, the shape of the first quartz crystal substrate 51 in plan view is rectangular. In particular, in this embodiment, it is a rectangle with the X-axis direction as the long side and the Z'-axis direction as the short side. Also, as shown in FIG. 7, the first quartz crystal substrate 51 has a vibration part 51A that vibrates in thickness shear, and a support part 51B that is located around the vibration part 51A and integrated with the vibration part 51A. The first quartz crystal substrate 51 of this embodiment is a flat type in which the vibration part 51A and the support part 51B have the same thickness. Also, the first quartz crystal substrate 51 is arranged so that the X-axis direction coincides with the A-axis direction, the Z'-axis direction coincides with the B-axis direction, and the Y'-axis direction coincides with the C-axis.

[0032] The electrode 52 has a first excitation electrode 521 arranged on the lower surface 511 of the vibration part 51A, a first terminal 522 arranged on the lower surface 511 of the support part 51B, and a first connection wiring 523 that electrically connects the first excitation electrode 521 and the first terminal 522. The electrode 53 has a second excitation electrode 531 arranged on the upper surface 512 of the vibration part 51A so as to face the first excitation electrode 521, a second terminal 532 arranged on the lower surface 511 of the support part 51B, and a second connection wiring 533 that electrically connects the second excitation electrode 531 and the second terminal 532. The first terminal 522 and the second terminal 532 are arranged side by side in the A-axis direction.

[0033] However, the first quartz crystal substrate 51 is not limited to this, and may be a mesa type in which the vibrating portion 51A is thicker than the supporting portion 51B, or an inverted mesa type in which the vibrating portion 51A is thinner than the supporting portion 51B. The first quartz crystal substrate 51 may be beveled by grinding the periphery to chamfer the edges, or may be convexly processed to make the upper and lower surfaces convex. In the case of a mesa type, the substrate may be configured to protrude only on one of the lower surface 511 side and the upper surface 512 side, and in the case of an inverted mesa type, the substrate may be configured to be recessed only on one of the lower surface 511 side and the upper surface 512 side.

[0034] The vibration element 5 is bonded to the upper surface 612 of the relay substrate 6 via an element-side bonding member 9. The element-side bonding member 9 has a first bonding member B1 and a second bonding member B2 that are spaced apart from each other. The first bonding member B1 contacts the first terminal 522 and the first relay wiring 621, and electrically connects the electrode 52 and the wiring 62. On the other hand, the second bonding member B2 contacts the second terminal 532 and the second relay wiring 631, and electrically connects the electrode 53 and the wiring 63.

[0035] The first bonding member B1 and the second bonding member B2 are arranged side by side in the A-axis direction. When an imaginary line J is defined as an axis that intersects with the center O of the first crystal substrate 51 and runs along the A-axis in a plan view, the first bonding member B1 and the second bonding member B2 are arranged on the imaginary line J. This allows the element-side bonding member 9 to support the vibration element 5 in a well-balanced manner.

[0036] The first bonding member B1, the second bonding member B2, the third bonding member B3, and the fourth bonding member B4 are not particularly limited as long as they have both electrical conductivity and bonding properties. For example, various metal bumps such as gold bumps, silver bumps, copper bumps, nickel bumps, and solder bumps, and conductive adhesives in which conductive fillers such as silver fillers are dispersed in various adhesives such as polyimide, epoxy, silicone, and acrylic adhesives can be used. However, it is preferable that the first, second, third, and fourth bonding members B1, B2, B3, and B4 are metal bumps. This prevents the conductive adhesive from spreading, unlike the conductive adhesive, and allows the first, second, third, and fourth bonding members B1, B2, B3, and B4 to be made smaller than the conductive adhesive. In addition, the generation of gas from the first, second, third, and fourth bonding members B1, B2, B3, and B4 can be suppressed, and environmental changes in the storage space S, especially pressure increases, can be effectively suppressed. In addition, a higher bonding strength can be achieved compared to the conductive adhesive.

[0037] Furthermore, the first, second, third, and fourth bonding members B1, B2, B3, and B4 are preferably any of the metal bumps, such as gold bumps, nickel bumps, and copper bumps, and more preferably gold bumps. In this embodiment, metal bumps are used as the first, second, third, and fourth bonding members B1, B2, B3, and B4. In this way, by using any of the gold bumps, nickel bumps, and copper bumps, particularly the gold bumps, as the first, second, third, and fourth bonding members B1, B2, B3, and B4, the linear expansion coefficient difference between the first, second, third, and fourth bonding members B1, B2, B3, and B4 and the first and second quartz crystal substrates 51 and 61 can be sufficiently reduced, and the occurrence of stress caused by the linear expansion coefficient difference can be effectively suppressed.

[0038] A gold bump is a bump made of gold (Au), a nickel bump is a bump made of nickel (Ni), and a copper bump is a bump made of copper (Cu). A gold bump may be made of substantially only gold (Au), or may contain, in addition to gold (Au), metal materials other than gold (Au), and various other additives. The same applies to nickel bumps and copper bumps.

[0039] Above, we have briefly described each part of the vibration device 1. In such a vibration device 1, the material, orientation, arrangement, etc. of each part are devised, so that stress is unlikely to occur and the generated stress is unlikely to be transmitted to the vibration element 5. Therefore, the vibration device 1 can exhibit excellent vibration characteristics.

[0040] This will be described below. As described above, in the vibration device 1, the vibration element 5 is bonded onto the intermediate substrate 6. The intermediate substrate 6 is formed from the same material as the vibration element 5, that is, quartz. In this way, if the intermediate substrate 6 is formed from the same material as the vibration element 5, the linear expansion coefficients of the intermediate substrate 6 and the vibration element 5 become the same, and it is considered that no stress due to the difference in linear expansion coefficients occurs between them. However, quartz has a characteristic that the linear expansion coefficient differs depending on the direction, and simply forming the intermediate substrate 6 from quartz, which is the same material as the vibration element 5, does not make the linear expansion coefficient difference between them the same. The linear expansion coefficient of quartz is 13.7 ppm / °C in the X-axis direction and the Y-axis direction, respectively, and 9.7 ppm / °C in the Z-axis direction.

[0041] Therefore, in the vibration device 1, as shown in FIG. 7, the X-axis of the first crystal substrate 51 of the vibration element 5 and the X-axis of the second crystal substrate 61 of the intermediate substrate 6 are aligned with the A-axis, which is the arrangement direction of the first bonding member B1 and the second bonding member B2 that bond them. That is, the direction of the X-axis of the first crystal substrate 51 of the vibration element 5, the direction of the X-axis of the second crystal substrate 61 of the intermediate substrate 6, and the arrangement directions of the first and second bonding members B1 and B2 are aligned with each other. With this configuration, the linear expansion coefficients along the A-axis direction can be made equal between the intermediate substrate 6 and the vibration element 5, and stress caused by the difference in thermal expansion coefficients is less likely to be applied to the vibration element 5. Therefore, the deterioration of the vibration characteristics of the vibration element 5 can be effectively suppressed.

[0042] As described above, the linear expansion coefficient of quartz crystal is equal in the X-axis direction to the Y-axis direction. In other words, the linear expansion coefficient is equal in any direction along the XY plane. Therefore, for example, as shown in FIG. 8, the Y-axis of the second quartz crystal substrate 61 may coincide with the A-axis, or as shown in FIG. 9, the X-axis and Y-axis of the second quartz crystal substrate 61 may both be inclined with respect to the A-axis. With these configurations, the same effect as this embodiment can be achieved.

[0043] As described above, the intermediate substrate 6 is bonded to the base 4 via the third bonding member B3 and the fourth bonding member B4 arranged in line along the B axis. The base 4 is mainly made of silicon, and the linear expansion coefficient of silicon is 2.8 ppm / °C. In contrast, the linear expansion coefficient of the intermediate substrate 6 in the Y-axis direction, which coincides with the B-axis direction, is 13.7 ppm / °C. As described above, the linear expansion coefficients of the base 4 and the intermediate substrate 6 in the B-axis direction are significantly different, and therefore, a stress in the B-axis direction due to the difference in linear expansion coefficients is generated between them, and the intermediate substrate 6 is curved and deformed into a substantially arc shape around the A-axis, as shown in FIG. 10.

[0044] Therefore, in order to prevent the stress caused by the bending deformation of the relay substrate 6 due to the difference in linear expansion coefficient with the base 4 from being transmitted to the vibration element 5, the first and second bonding members B1 and B2 are arranged in the A-axis direction perpendicular to the B-axis direction, which is the direction of the bending deformation. That is, in a plan view, the first and second bonding members B1 and B2 are arranged in a direction that intersects, particularly perpendicular to, the direction in which the third and fourth bonding members B3 and B4 are arranged. Therefore, it is possible to suppress the change in the relative positional relationship between the first and second bonding members B1 and B2 caused by the bending deformation of the relay substrate 6, and the stress caused by the bending deformation of the relay substrate 6 is less likely to be applied to the vibration element 5. In particular, by making the direction in which the first and second bonding members B1 and B2 are arranged perpendicular to the direction in which the third and fourth bonding members B3 and B4 are arranged as in this embodiment, the relative positional relationship between the first and second bonding members B1 and B2 can be kept constant regardless of the state of the relay substrate 6, that is, whether the relay substrate 6 is bent or not. Therefore, the stress caused by the bending deformation of the intermediate substrate 6 is less likely to be applied to the vibration element 5.

[0045] However, without being limited to this, for example, the first and second joining members B1, B2 may be arranged side by side in a direction that intersects at an angle other than perpendicular to the B-axis direction in which the third and fourth joining members B3, B4 are arranged, or may be arranged side by side in the B-axis direction in which the third and fourth joining members B3, B4 are arranged.

[0046] As shown in FIG. 5, when the line segment connecting the centers of the first and second bonding members B1 and B2 in a plan view is defined as line segment L1, and the line segment connecting the centers of the third and fourth bonding members B3 and B4 is defined as line segment L2, the line segment L1 is a perpendicular bisector of the line segment L2. As a result, as shown in FIG. 10, the first and second bonding members B1 and B2 can be disposed at the inflection point of the bending deformation of the relay substrate 6. Therefore, the inclination of the first and second bonding members B1 and B2 around the A axis caused by the bending deformation of the relay substrate 6 can be suppressed. Therefore, the posture of the vibration element 5 is stabilized, and contact with the relay substrate 6 and the base 4 can be suppressed.

[0047] In this embodiment, the third and fourth bonding members B3 and B4 are arranged so as not to overlap with the vibration element 5 in a plan view. Specifically, the third bonding member B3 is located on the positive side of the B axis direction with respect to the vibration element 5, and the fourth bonding member B4 is located on the negative side of the B axis direction with respect to the vibration element 5. This allows the third and fourth bonding members B3 and B4 to be sufficiently spaced apart, and the relay substrate 6 can be supported more stably. However, this is not limited to this, and for example, as shown in FIG. 11, the third and fourth bonding members B3 and B4 may be arranged so as to overlap with the vibration element 5. This allows the length of the relay substrate 6 in the B axis direction to be shorter than in this embodiment, and therefore the vibration device 1 can be made smaller in size.

[0048] Moreover, the first, second, third, and fourth bonding members B1, B2, B3, and B4 are gold bumps. The linear expansion coefficient of gold (Au), which is a material of the gold bumps, is 14.3 ppm / °C. Therefore, the difference in the linear expansion coefficient between the first and second bonding members B1, B2 and the first and second crystal substrates 51, 61 can be sufficiently suppressed to a small value. As a result, the thermal stress generated at the interface between the first and second bonding members B1, B2 and the vibration element 5, the thermal stress generated at the interface between the first and second bonding members B1, B2 and the relay substrate 6, and the thermal stress generated at the interface between the third and fourth bonding members B3, B4 and the relay substrate 6 can be sufficiently suppressed to a small value. Therefore, the vibration device 1 is one in which stress is unlikely to be generated and further the generated stress is unlikely to be transmitted to the vibration element 5. The linear expansion coefficient of copper (Cu), which is a constituent material of copper bumps, which is also preferred like gold bumps, is 16.8 ppm / ° C., and the linear expansion coefficient of nickel (Ni), which is a constituent material of nickel bumps, is 12.8 ppm / ° C. Therefore, although the effect is slightly inferior to that of gold bumps, these can also fully exert the above-mentioned effects.

[0049] The above describes the vibration device 1. As described above, the vibration device 1 includes a first crystal substrate 51 having a front-back relationship and including a lower surface 511 as a first surface along the X-axis, which is an electric axis, and an upper surface 512 as a second surface, a first excitation electrode 521 arranged on the lower surface 511, a second excitation electrode 531 arranged on the upper surface 512 facing the first excitation electrode 521, a vibration element 5 having a first terminal 522 electrically connected to the first excitation electrode 521 and a second terminal 532 electrically connected to the second excitation electrode 531, a substrate 41 located on the lower surface 511 side of the vibration element 5, a base 4 having a first substrate wiring 42 and a second substrate wiring 43 arranged on the substrate 41, a second crystal substrate 61 arranged between the vibration element 5 and the base 4, and a thickness direction of which is along the Z-axis, which is an optical axis, and an upper surface 6 which is a third surface on the vibration element 5 side of the second crystal substrate 61. 12, a relay board 6 including a first relay wiring 621 and a second relay wiring 631 arranged on a lower surface 611 which is the fourth surface on the base 4 side and is in a front-back relationship with the upper surface 612, a third relay wiring 622 electrically connected to the first relay wiring 621 and a fourth relay wiring 632 electrically connected to the second relay wiring 631, an element-side bonding member 9 including a first bonding member B1 electrically connecting the first terminal 522 and the first relay wiring 621 and a second bonding member B2 electrically connecting the second terminal 532 and the second relay wiring 631 and bonding the vibration element 5 to the relay board 6, and a base-side bonding member 8 including a third bonding member B3 electrically connecting the first board wiring 42 and the third relay wiring 622 and a fourth bonding member B4 electrically connecting the second board wiring 43 and the fourth relay wiring 632 and bonding the base 4 and the relay board 6. The first bonding member B1 and the second bonding member B2 are arranged side by side in the direction along the X-axis. With this configuration, the linear expansion coefficients of the intermediate substrate 6 and the vibration element 5 along the arrangement direction of the first and second bonding members B1 and B2 can be made equal. Therefore, stress caused by the difference in thermal expansion coefficients is less likely to be applied to the vibration element 5. As a result, deterioration of the vibration characteristics of the vibration element 5 can be effectively suppressed.

[0050] As described above, the third bonding member B3 and the fourth bonding member B4 are arranged side by side in a direction intersecting the direction in which the first bonding member B1 and the second bonding member B2 are arranged in a plan view of the vibration element 5. This makes it possible to suppress a change in the relative positional relationship between the first and second bonding members B1 and B2 caused by the bending deformation of the relay substrate 6 due to the linear expansion difference with the base 4. Therefore, the stress caused by the bending deformation of the relay substrate 6 is less likely to be applied to the vibration element 5.

[0051] As described above, the third bonding member B3 and the fourth bonding member B4 are arranged in a direction perpendicular to the direction in which the first bonding member B1 and the second bonding member B2 are arranged in a plan view of the vibration element 5. This makes it possible to keep the relative positional relationship between the first and second bonding members B1 and B2 constant regardless of the state of the relay substrate 6, that is, whether or not bending deformation occurs. Therefore, the stress caused by bending deformation of the relay substrate 6 is less likely to be applied to the vibration element 5.

[0052] As described above, the first bonding member B1, the second bonding member B2, the third bonding member B3, and the fourth bonding member B4 are each a metal bump. This prevents the conductive adhesive from spreading, and the first, second, third, and fourth bonding members B1, B2, B3, and B4 can be made smaller than the conductive adhesive. In addition, the generation of gas from the first, second, third, and fourth bonding members B1, B2, B3, and B4 can be suppressed, and environmental changes in the storage space S, particularly pressure increases, can be effectively suppressed. In addition, a higher bonding strength can be achieved than the conductive adhesive.

[0053] As described above, the metal bumps constituting the first, second, third and fourth bonding members B1, B2, B3 and B4 are gold bumps made of gold (Au), nickel bumps made of nickel (Ni) or copper bumps made of copper (Cu). This makes it possible to sufficiently reduce the thermal stresses occurring at the interfaces between the first and second bonding members B1 and B2 and the vibration element 5, the thermal stresses occurring at the interfaces between the first and second bonding members B1 and B2 and the relay substrate 6, and the thermal stresses occurring at the interfaces between the third and fourth bonding members B3 and B4 and the relay substrate 6.

[0054] As described above, the first bonding member B1 and the second bonding member B2 are disposed on the imaginary line J that intersects with the center O of the first crystal substrate 51 and runs along the X-axis in a plan view of the vibration element 5. This allows the vibration element 5 to be supported in a well-balanced manner.

[0055] <Second embodiment> Fig. 12 is a plan view showing a vibration device according to a second embodiment of the present invention Fig. 13 is a graph showing the amount of displacement of a vibration part.

[0056] The resonator device 1 according to this embodiment is similar to the resonator device 1 according to the first embodiment, except that the first and second joining members B1 and B2 are arranged differently. In the following description, the resonator device 1 according to the second embodiment will be described with a focus on the differences from the first embodiment, and the description of the similarities will be omitted. In addition, in FIG. 12, the same reference numerals are used for the same configurations as those in the above-described embodiment.

[0057] As shown in FIG. 12, the first bonding member B1 and the second bonding member B2 are arranged along the outer edge of the vibration element 5 in a plan view. In addition, when the region of the first excitation electrode 521 extended in the A-axis direction, i.e., the X-axis direction of the first crystal substrate 51 in a plan view is defined as the first region Q1, and the region of the first excitation electrode 521 extended in the B-axis direction perpendicular to the A-axis direction, i.e., the Z'-axis direction of the first crystal substrate 51 is defined as the second region Q2, the first bonding member B1 and the second bonding member B2 are arranged so as not to overlap with the first region Q1 and the second region Q2. This allows the first bonding member B1 and the second bonding member B2 to be arranged farther away from the center of the vibration part 51A of the vibration element 5. Therefore, the stress propagation path from the first and second bonding members B1 and B2 to the vibration part 51A becomes longer, and stress is less likely to be applied to the vibration part 51A. As a result, the deterioration of the vibration characteristics of the vibration element 5 can be effectively suppressed.

[0058] FIG. 13 shows a graph comparing the displacement of the vibration part 51 for the first embodiment, the present embodiment, and a comparative example in which the first and second bonding members B1 and B2 are arranged side by side in the B-axis direction. In the figure, the solid line J1 represents the first embodiment, the solid line J2 represents the present embodiment, and the solid line J3 represents the comparative example. Note that the smaller the displacement in the C-axis direction, the less likely stress is to be applied to the vibration part 51A. As can be seen from the figure, the first embodiment provides a sufficient effect compared to the comparative example, but the present embodiment provides an even greater effect.

[0059] The second embodiment as described above can also achieve the same effects as the first embodiment described above.

[0060] <Third embodiment> FIG. 14 is a plan view showing a vibration device according to a third embodiment of the present invention.

[0061] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 5 is different. In the following description, the vibration device 1 according to the third embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in FIG. 14, the same reference numerals are used for the same configurations as those in the above-mentioned embodiments.

[0062] As shown in FIG. 14, in the vibration device 1 of this embodiment, the first terminal 522 and the second terminal 532 of the vibration element 5 are located on the negative side in the B-axis direction of the vibration part 51A.

[0063] The third embodiment as described above can also achieve the same effects as the first embodiment described above.

[0064] <Fourth embodiment> FIG. 15 is a cross-sectional view showing a vibration element included in a vibration device according to a fourth embodiment of the present invention.

[0065] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 5 is different. In the following description, the vibration device 1 according to the fourth embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in FIG. 15, the same reference numerals are used for the same configurations as those in the above-mentioned embodiments.

[0066] In the vibration device 1 according to this embodiment, as shown in FIG. 15, the vibration element 5 is of a mesa type. That is, in the first quartz crystal substrate 51, the vibration portion 51A is thicker than the support portion 51B. The vibration portion 51A protrudes on both sides in the Y'-axis direction relative to the support portion 51B. By using such a mesa type vibration element 5, the thickness-shear vibration of the vibration portion 51A can be effectively confined to the vibration portion 51A. Therefore, the vibration leakage of the vibration element 5 can be effectively suppressed, resulting in a vibration element 5 with excellent vibration characteristics.

[0067] As described above, in the vibration device 1 of this embodiment, the first quartz substrate 51 has the vibration part 51A in which the first excitation electrode 521 and the second excitation electrode 531 are arranged, and the support part 51B in which the first terminal 522 and the second terminal 532 are arranged and which is thinner than the vibration part 51A. This makes it possible to effectively confine thickness-shear vibration to the vibration part 51A. Therefore, it is possible to effectively suppress vibration leakage of the vibration element 5, resulting in a vibration element 5 with excellent vibration characteristics.

[0068] The fourth embodiment as described above can also achieve the same effects as the first embodiment described above.

[0069] <Fifth embodiment> FIG. 16 is a cross-sectional view showing a vibration element included in a vibration device according to a fifth embodiment of the present invention.

[0070] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 5 is different. In the following description, the vibration device 1 according to the fifth embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in FIG. 16, the same reference numerals are used for the same configurations as those in the above-mentioned embodiments.

[0071] As shown in FIG. 16, in the vibration device 1 according to this embodiment, the vibration element 5 is mesa-shaped, and the portion where the first and second terminals 522 and 532 are arranged is thick and protrudes from the surroundings. That is, the first quartz substrate 51 has a vibration part 51A where the first excitation electrode 521 and the second excitation electrode 531 are arranged, a support part 51B where the first terminal 522 and the second terminal 532 are arranged, and a connection part 51C located between the vibration part 51A and the support part 51B and thinner than the vibration part 51A and the support part 51B. This makes it possible to effectively confine thickness-shear vibration in the vibration part 51A, as in the fourth embodiment described above. Furthermore, since the support part 51B where the first and second terminals 522 and 532 are arranged and which is joined to the relay substrate 6 is thickened, the mechanical strength of the vibration element 5 can be increased.

[0072] The fifth embodiment can also achieve the same effects as the first embodiment described above.

[0073] Sixth embodiment FIG. 17 is a cross-sectional view showing a vibration module according to a sixth embodiment of the present invention.

[0074] The vibration module 1000 shown in FIG. 17 includes a support substrate 1010, a circuit substrate 1020 mounted on the support substrate 1010, a vibration device 1 mounted on the circuit substrate 1020, and a molding material M that molds the circuit substrate 1020 and the vibration device 1.

[0075] The support substrate 1010 is, for example, an interposer substrate. A plurality of connection terminals 1011 are arranged on the upper surface of the support substrate 1010, and a plurality of mounting terminals 1012 are arranged on the lower surface. Internal wiring (not shown) is arranged within the support substrate 1010, and each connection terminal 1011 is electrically connected to a corresponding mounting terminal 1012 via this internal wiring. Such a support substrate 1010 is not particularly limited, and for example, a silicon substrate, a ceramic substrate, a resin substrate, a glass substrate, a glass epoxy substrate, or the like can be used.

[0076] The circuit board 1020 is bonded to the upper surface of the support substrate 1010 via a die attachment material. The circuit board 1020 has an oscillation circuit 1023 formed thereon, which oscillates the vibration element 5 of the vibration device 1 to generate a frequency of a reference signal such as a clock signal, and has a plurality of terminals 1022 electrically connected to the oscillation circuit 1023 disposed on the upper surface of the circuit board 1020. Some of the terminals 1022 are electrically connected to the connection terminals 1011 via bonding wires BW, and some of the terminals 1022 are electrically connected to the vibration device 1 via a conductive bonding member B such as solder.

[0077] The molding material M molds the circuit board 1020 and the vibration device 1, and protects them from moisture, dust, impact, etc. The molding material M is not particularly limited, but for example, a thermosetting epoxy resin can be used, and molding can be performed by a transfer molding method.

[0078] The vibration module 1000 as described above includes the vibration device 1. Therefore, it is possible to enjoy the effects of the vibration device 1 described above, and to exhibit excellent reliability.

[0079] Seventh embodiment FIG. 18 is a perspective view illustrating a smartphone according to the seventh embodiment.

[0080] The smartphone 1200 shown in Fig. 18 is an application of the electronic device of the present invention. The smartphone 1200 has a vibration device 1 used as a part of an oscillator, and an arithmetic processing circuit 1210 that operates based on a signal output from the vibration device 1. For example, based on an input signal input from a screen 1208, the arithmetic processing circuit 1210 can change the display screen, start a specific application, sound an alarm or sound effect, or drive a vibration motor to vibrate the main body.

[0081] A smartphone 1200 as such an electronic device includes the vibration device 1 and an arithmetic processing circuit 1210 that operates based on a signal output from the vibration device 1. Therefore, the smartphone 1200 can enjoy the effects of the vibration device 1 described above and can exhibit high reliability.

[0082] In addition to the smartphone 1200 described above, electronic devices equipped with the vibration device 1 can be applied to, for example, personal computers, digital still cameras, tablet terminals, watches, smart watches, inkjet printers, televisions, smart glasses, wearable terminals such as HMDs (head mounted displays), video cameras, video tape recorders, car navigation devices, drive recorders, electronic notebooks, electronic dictionaries, electronic translators, calculators, electronic game devices, toys, word processors, workstations, videophones, security television monitors, electronic binoculars, POS terminals, medical equipment, fish finders, various measuring instruments, equipment for mobile terminal base stations, various instruments for vehicles, railway cars, aircraft, helicopters, ships, etc., flight simulators, network servers, etc.

[0083] Eighth embodiment FIG. 19 is a perspective view showing the automobile according to the eighth embodiment.

[0084] 19 includes a system 1502 such as an engine system, a brake system, and a keyless entry system. The automobile 1500 also includes a vibration device 1 used as a part of an oscillator, and an arithmetic processing circuit 1510 that operates based on a signal output from the vibration device 1 and controls the system 1502.

[0085] In this way, the automobile 1500 as a moving object includes the vibration device 1 and the arithmetic processing circuit 1510 that operates based on a signal output from the vibration device 1. Therefore, the automobile 1500 can enjoy the effects of the vibration device 1 described above and can exhibit high reliability.

[0086] Note that the moving object equipped with the vibration device 1 may be, in addition to the automobile 1500, a robot, a drone, a two-wheeled vehicle, an airplane, a ship, a train, a rocket, a spaceship, or the like.

[0087] The vibration device, vibration module, electronic device, and moving body of the present invention have been described above based on the illustrated embodiments, but the present invention is not limited thereto, and the configuration of each part can be replaced with any configuration having a similar function. In addition, any other configuration may be added to the present invention. In addition, the present invention may be a combination of any two or more configurations of the above-mentioned embodiments. [Explanation of symbols]

[0088] 1...vibration device, 3...lid, 32...recess, 4...base, 41...substrate, 410...insulating film, 411...lower surface, 412...upper surface, 413...through hole, 414...through hole, 42...first substrate wiring, 421...internal terminal, 422...external terminal, 423...through electrode, 43...second substrate wiring, 431...internal terminal, 432...external terminal, 433...through electrode, 44, 45...dummy terminal, 5...vibration element, 51... First quartz crystal substrate, 51A... vibrating portion, 51B... supporting portion, 51C... connecting portion, 511... lower surface, 512... upper surface, 52... electrode, 521... first excitation electrode, 522... first terminal, 523... first connection wiring, 53... electrode, 531... second excitation electrode, 532... second terminal, 533... second connection wiring, 6... relay substrate, 61... second quartz crystal substrate, 611... lower surface, 612... upper surface, 62... wiring, 621... first relay wiring, 6 22...third relay wiring, 623...connection wiring, 63...wiring, 631...second relay wiring, 632...fourth relay wiring, 633...connection wiring, 7...joint member, 8...base side joint member, 9...element side joint member, 1000...vibration module, 1010...support substrate, 1011...connection terminal, 1012...mounting terminal, 1020...circuit board, 1022...terminal, 1023...oscillating circuit, 1200...smartphone , 1208...screen, 1210...arithmetic processing circuit, 1500...automobile, 1502...system, 1510...arithmetic processing circuit, B...joint member, B1...first joint member, B2...second joint member, B3...third joint member, B4...fourth joint member, BW...bonding wire, J...virtual line, L1, L2...line segment, M...mold material, O...center, Q1...first region, Q2...second region, S...storage space, θ...angle

Claims

1. a vibration element including a first quartz crystal substrate having a first surface and a second surface along an X-axis that is an electric axis, a first excitation electrode disposed on the first surface, a second excitation electrode disposed on the second surface so as to face the first excitation electrode, and a first terminal disposed on the first surface and electrically connected to the first excitation electrode and a second terminal electrically connected to the second excitation electrode; A base including a substrate located on the first surface side of the vibration element, and a first substrate wiring and a second substrate wiring arranged on the substrate; a relay substrate including: a second quartz crystal substrate disposed between the vibration element and the base, the thickness direction of which is along the Z-axis which is the optical axis; a first relay wiring and a second relay wiring disposed on a third surface of the second quartz crystal substrate on the vibration element side; a third relay wiring electrically connected to the first relay wiring and a fourth relay wiring electrically connected to the second relay wiring, which are reverse to the third surface and disposed on a fourth surface of the base side; an element-side bonding member that includes a first bonding member that electrically connects the first terminal and the first relay wiring and a second bonding member that electrically connects the second terminal and the second relay wiring, and that bonds the vibration element to the relay substrate; a third bonding member electrically connecting the first substrate wiring and the third relay wiring and a fourth bonding member electrically connecting the second substrate wiring and the fourth relay wiring, and a base side bonding member bonding the base and the relay substrate; The first joint member and the second joint member are arranged side by side in a direction along the X-axis, the third bonding member and the fourth bonding member are arranged side by side in a direction intersecting a direction in which the first bonding member and the second bonding member are arranged in a plan view of the vibration element, A vibration device characterized in that, in a planar view of the vibration element, the positions of the third bonding member and the fourth bonding member in the direction along the X-axis are between the first bonding member and the second bonding member.

2. The vibration device according to claim 1 , wherein the third bonding member and the fourth bonding member are arranged in a direction perpendicular to a direction in which the first bonding member and the second bonding member are arranged in a plan view of the vibration element.

3. The vibration device according to claim 1 , wherein the first bonding member, the second bonding member, the third bonding member and the fourth bonding member are each a metal bump.

4. The resonator device according to claim 3 , wherein the metal bump is a gold bump made of gold (Au), a nickel bump made of nickel (Ni), or a copper bump made of copper (Cu).

5. In a plan view of the vibration element, a region in which the first excitation electrode extends in a direction along the X-axis is defined as a first region, and a region in which the first excitation electrode extends in a direction perpendicular to the direction along the X-axis is defined as a second region. The vibration device according to claim 1 , wherein the first joint member and the second joint member do not overlap with the first region and the second region.

6. The vibration device according to claim 1 , wherein the first bonding member and the second bonding member are arranged on a virtual line that intersects with a center of the first quartz crystal substrate and extends along the X-axis in a plan view of the vibration element.

7. The first quartz crystal substrate is a vibration section in which the first excitation electrode and the second excitation electrode are disposed; The vibration device according to claim 1 , further comprising: a support portion on which the first terminal and the second terminal are arranged, the support portion being thinner than the vibration portion.

8. The first quartz crystal substrate is a vibration section in which the first excitation electrode and the second excitation electrode are disposed; a support portion on which the first terminal and the second terminal are disposed; The vibration device according to claim 1 , further comprising: a connection portion located between the vibration portion and the support portion, the connection portion being thinner than the vibration portion and the support portion.

9. A vibration module comprising the vibration device according to claim 1 or 2.

10. A vibration device according to claim 1 or 2, and a processing circuit that operates based on a signal output from the vibration device.

11. A vibration device according to claim 1 or 2, and a processing circuit that operates based on a signal output from the vibration device.

Images