Angular velocity sensor

Abstract

To provide an angular velocity sensor capable of precisely detecting angular velocity.SOLUTION: An angular velocity sensor has: an angular velocity detection element having a drive vibration arm in which a drive signal electrode to which a drive signal is applied is disposed, and a detection vibration arm in which a detection signal electrode for outputting a detection signal is disposed; and a support board having multiple leads for supporting the angular velocity detection element and a board for supporting the multiple leads. The multiple leads include a detection signal lead electrically connected to the detection signal electrode, the detection signal lead overlaps the drive signal electrode in a plan view of the support board, and a constant potential layer is disposed between the detection signal lead and the drive signal electrode.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an angular velocity sensor. [Background technology]

[0002] The angular velocity sensor described in Patent Document 1 includes a package, an angular velocity detection element disposed in the package, a support substrate, and a circuit element.

[0003] The angular velocity detecting element has a base located at its center, a pair of detection vibration arms extending from the base in both directions in the Y-axis direction, a pair of connecting arms extending from the base in both directions in the X-axis direction, a pair of first drive vibration arms extending from a tip of one connecting arm in both directions in the Y-axis direction, and a pair of second drive vibration arms extending from a tip of the other connecting arm in both directions in the Y-axis direction. The angular velocity detecting element also has a first detection signal electrode arranged on both main surfaces of one of the detection vibration arms and a first detection ground electrode arranged on both side surfaces, a second detection signal electrode arranged on both main surfaces of the other detection vibration arm and a second detection ground electrode arranged on both side surfaces, drive signal electrodes arranged on both main surfaces of each first drive vibration arm and on both side surfaces of each second drive vibration arm, and drive ground electrodes arranged on both side surfaces of each first drive vibration arm and on both main surfaces of each second drive vibration arm.

[0004] The support substrate has six leads, the bases of which are fixed to the tips of the angular velocity sensing elements, and a base material supporting the base ends of each lead. The six leads include one lead electrically connected to the first detection signal electrode, one lead electrically connected to the first detection ground electrode, one lead electrically connected to the second detection signal electrode, one lead electrically connected to the second detection ground electrode, one lead electrically connected to the drive signal electrode, and one lead electrically connected to the drive ground electrode. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-169406 Summary of the Invention [Problem to be solved by the invention]

[0006] In the angular velocity sensor of Patent Document 1, the leads electrically connected to the first and second detection signal electrodes intersect with the drive signal electrodes near the angular velocity detection element in a plan view. This causes electrostatic coupling between the leads and the drive signal electrodes, making it easier for noise from the drive signal electrodes to be carried in the detection signal propagating through the leads. This can result in a decrease in angular velocity detection accuracy. [Means for solving the problem]

[0007] The angular velocity sensor of the present invention includes an angular velocity detection element having a drive vibration arm in which a drive signal electrode to which a drive signal is applied is arranged, and a detection vibration arm in which a detection signal electrode that outputs a detection signal is arranged; a support substrate having a plurality of leads supporting the angular velocity detection element and a substrate supporting the plurality of leads; the plurality of leads include a detection signal lead electrically connected to the detection signal electrode, the detection signal leads overlap the drive signal electrodes in a plan view of the support substrate; A constant potential layer is disposed between the detection signal lead and the drive signal electrode. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an angular velocity sensor according to a first embodiment. [Figure 2] 2 is a cross-sectional view showing the angular velocity sensor shown in FIG. 1 in a state before the lid is sealed. [Figure 3] FIG. 2 is a top view showing the angular velocity detection element. [Figure 4] 3A and 3B are schematic diagrams showing drive vibration modes of an angular velocity detection element. [Figure 5] 3A and 3B are schematic diagrams illustrating detection vibration modes of an angular velocity detection element. [Figure 6] FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line AA in FIG. 6. [Figure 8] FIG. 7 is a cross-sectional view taken along line BB in FIG. [Figure 9] FIG. [Figure 10] FIG. 2 is a top view showing a state in which the angular velocity sensor is supported by a support substrate. [Figure 11] FIG. 10 is a cross-sectional view for explaining a problem in the related art. [Figure 12] 2 is a cross-sectional view for explaining the effect of the angular velocity sensor shown in FIG. 1. FIG. [Figure 13] FIG. 10 is a cross-sectional view for explaining a problem in the related art. [Figure 14] 2 is a cross-sectional view for explaining the effect of the angular velocity sensor shown in FIG. 1. FIG. [Figure 15] FIG. 10 is a top view showing a modified example of the support substrate. [Figure 16] FIG. 10 is a cross-sectional view of a support substrate according to a second embodiment. [Figure 17] FIG. 10 is a cross-sectional view of a support substrate according to a second embodiment. [Figure 18] FIG. 10 is a top view of a support substrate according to a third embodiment. [Figure 19] 19 is a cross-sectional view taken along line CC in FIG. 18. [Figure 20] 19 is a cross-sectional view for explaining the effect of the support substrate shown in FIG. 18. FIG. [Figure 21] FIG. 10 is a cross-sectional view showing a modified example of the support substrate. [Figure 22] FIG. 10 is a cross-sectional view showing a modified example of the support substrate. [Figure 23] FIG. 10 is a top view of a support substrate according to a fourth embodiment. [Figure 24] 24 is a cross-sectional view taken along line DD in FIG. 23. DETAILED DESCRIPTION OF THE INVENTION

[0009] The angular velocity sensor of the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings. For ease of explanation, each drawing illustrates three mutually orthogonal axes as the X-axis, Y-axis, and Z-axis. The direction along the X-axis will also be referred to as the "X-axis direction," the direction along the Y-axis will also be referred to as the "Y-axis direction," and the direction along the Z-axis will also be referred to as the "Z-axis direction." The Z-axis is aligned vertically, and the arrowed side will also be referred to as the "upper" side and the opposite side as the "lower" side. Hereinafter, a planar view of the support substrate 4, i.e., a planar view from the Z-axis direction, will also be referred to simply as the "planar view."

[0010] First Embodiment FIG. 1 is a cross-sectional view of the angular velocity sensor according to the first embodiment. FIG. 2 is a cross-sectional view showing the angular velocity sensor shown in FIG. 1 in a state before the lid is sealed. FIG. 3 is a top view showing an angular velocity detection element. FIG. 4 is a schematic diagram showing a drive vibration mode of the angular velocity detection element. FIG. 5 is a schematic diagram showing a detection vibration mode of the angular velocity detection element. FIG. 6 is a top view of a support substrate. FIG. 7 is a cross-sectional view taken along line AA in FIG. 6. FIG. 8 is a cross-sectional view taken along line BB in FIG. 6. FIG. 9 is a bottom view of a support substrate. FIG. 10 is a top view showing a state in which the angular velocity sensor is supported by the support substrate. FIG. 11 is a cross-sectional view for explaining problems of the related art. FIG. 12 is a cross-sectional view for explaining the effect of the angular velocity sensor shown in FIG. 1. FIG. 13 is a cross-sectional view for explaining problems of the related art. FIG. 14 is a cross-sectional view for explaining the effect of the angular velocity sensor shown in FIG. 1. FIG. 15 is a top view showing a modified support substrate.

[0011] Angular velocity sensor 1 shown in Fig. 1 is a sensor that detects angular velocity ωz about the Z axis, and includes angular velocity detection element 3 to which angular velocity ωz is applied, support substrate 4 that supports angular velocity detection element 3, circuit element 5 that controls the driving of angular velocity detection element 3, and package 2 that houses these. Within package 2, angular velocity detection element 3, support substrate 4, and circuit element 5 are arranged overlapping in the Z axis direction. With this configuration, the expansion of angular velocity sensor 1 in the X axis and Y axis directions, i.e., its footprint, is reduced, allowing for the miniaturization of angular velocity sensor 1.

[0012] [Package 2] First, the package 2 will be described. As shown in FIG. 1, the package 2 includes a cavity-shaped base 21 having a recess 211 opening to its upper surface, and a plate-shaped lid 22 joined to the upper surface of the base 21 via a seam ring 23 and closing the opening of the recess 211. The package 2 has an internal space S, in which the angular velocity sensing element 3, the support substrate 4, and the circuit element 5 are housed so as to overlap in the Z-axis direction. This configuration allows the package 2 to protect the angular velocity sensing element 3 and the circuit element 5. The internal space S is hermetically sealed and is in a reduced pressure state, preferably closer to a vacuum. This reduces viscous resistance and allows the angular velocity sensing element 3 to be driven efficiently. However, the atmosphere in the internal space S is not particularly limited.

[0013] 2, a groove 221 is formed on the back surface of the lid 22 before hermetically sealing, and the inside and outside of the internal space S are in communication with each other via the groove 221. After the internal space S is evacuated via the groove 221, the groove 221 is closed by irradiating the vicinity of the groove 221 of the lid 22 with an energy beam EL such as a laser beam to melt the groove 221. This hermetically seals the internal space S. However, the method for hermetically sealing the internal space S is not particularly limited.

[0014] The constituent material of the base 21 is not particularly limited, but various ceramics such as aluminum oxide can be used. The constituent material of the lid 22 is also not particularly limited, but it is preferable that the constituent material has a linear expansion coefficient similar to that of the constituent material of the base 21. For example, if the constituent material of the base 21 is ceramic, it is preferable that the lid 22 be made of an alloy such as Kovar.

[0015] The lid 22 is connected to the ground (reference potential) when the angular velocity sensor 1 is in use. Therefore, the lid 22 functions as a shield that blocks external disturbances, and can effectively suppress deterioration of the characteristics of the angular velocity sensor 1. However, the present invention is not limited to this, and the lid 22 does not have to be connected to the ground.

[0016] 1, the recess 211 has a first recess 211a that opens to the top surface of the base 21, a second recess 211b that opens to the bottom surface of the first recess 211a and has a smaller opening area than the first recess 211a, and a third recess 211c that opens to the bottom surface of the second recess 211b and has a smaller opening area than the second recess 211b. The circuit element 5 is fixed to the bottom surface of the third recess 211c, and the support substrate 4 is fixed to the bottom surface of the first recess 211a, and the angular velocity detection element 3 is fixed to the support substrate 4.

[0017] Furthermore, a plurality of internal terminals 231 are arranged on the bottom surface of the first recess 211a, a plurality of internal terminals 232 are arranged on the bottom surface of the second recess 211b, and a plurality of external terminals 233 are arranged on the bottom surface of the base 21. The plurality of internal terminals 232 include those electrically connected to the internal terminals 231 via internal wiring (not shown) formed in the base 21 and those electrically connected to the external terminals 233 via the internal wiring. Each internal terminal 231 is electrically connected to the support substrate 4 via a conductive bonding member B1, and each internal terminal 232 is electrically connected to the circuit element 5 via a bonding wire BW. The number and arrangement of the internal terminals 231, 232 and the external terminals 233 are not particularly limited and may be set appropriately depending on, for example, the number of terminals of the angular velocity sensing element 3 and the circuit element 5.

[0018] [Angular velocity sensor 3] Next, the angular velocity detection element 3 will be described. The angular velocity detection element 3 is a quartz crystal vibration element. As shown in Fig. 3, the angular velocity detection element 3 has a base 30 located in the center, a pair of detection vibration arms 31 and 32 extending from the base 30 on both sides in the Y-axis direction, a pair of support arms 33 and 34 extending from the base 30 on both sides in the X-axis direction, a pair of drive vibration arms 35 and 36 extending from the tip of one support arm 33 on both sides in the Y-axis direction, and a pair of drive vibration arms 37 and 38 extending from the tip of the other support arm 34 on both sides in the Y-axis direction. The angular velocity detection element 3 is supported by a support substrate 4 at the base 30.

[0019] The angular velocity detection element 3 also has a first detection signal electrode E1 arranged on both main surfaces of the detection vibration arm 31, a first detection ground electrode E2 arranged on both side surfaces of the detection vibration arm 31, a second detection signal electrode E3 arranged on both main surfaces of the detection vibration arm 32, a second detection ground electrode E4 arranged on both side surfaces of the detection vibration arm 32, a drive signal electrode E5 arranged on both main surfaces of the drive vibration arms 35, 36 and both side surfaces of the drive vibration arms 37, 38, and a drive ground electrode E6 arranged on both side surfaces of the drive vibration arms 35, 36 and both main surfaces of the drive vibration arms 37, 38.

[0020] Six terminals T1, T2, T3, T4, T5, and T6 are arranged on the underside of the base 30. Although not shown, the terminal T1 is electrically connected to the first detection signal electrode E1, the terminal T2 is electrically connected to the first detection ground electrode E2, the terminal T3 is electrically connected to the second detection signal electrode E3, the terminal T4 is electrically connected to the second detection ground electrode E4, the terminal T5 is electrically connected to the drive signal electrode E5, and the terminal T6 is electrically connected to the drive ground electrode E6.

[0021] The angular velocity detecting element 3 described above detects the angular velocity ωz in the following manner. When a drive signal is applied to the drive signal electrode E5, the drive vibration arms 35, 36 and the drive vibration arms 37, 38 flexurally vibrate in opposite phases along the XY plane, as shown in FIG. 4 (hereinafter, this state is also referred to as the "drive vibration mode"). In this state, the vibration of the drive vibration arms 35, 36 and the vibration of the drive vibration arms 37, 38 are canceled, and the detection vibration arms 31, 32 do not substantially vibrate. When an angular velocity ωz is applied to the angular velocity detecting element 3 while it is driven in the drive vibration mode, as shown in FIG. 5, the Coriolis force acts on the drive vibration arms 35, 36, 37, 38, exciting flexural vibration in the Y-axis direction, and the detection vibration arms 31, 32 flexurally vibrate in the X-axis direction in response to this flexural vibration (hereinafter, this state is also referred to as the "detection vibration mode").

[0022] The charge generated in the detection vibration arm 31 by such a detection vibration mode is extracted as a first detection signal from the first detection signal electrode E1, and the charge generated in the detection vibration arm 32 is extracted as a second detection signal from the second detection signal electrode E3, and the angular velocity ωz is determined based on these first and second detection signals.

[0023] The above describes the angular velocity detection element 3, but the configuration of the angular velocity detection element 3 is not particularly limited as long as it has at least one drive vibration arm having a drive signal electrode and at least one detection vibration arm having a detection signal electrode.

[0024] [Support substrate 4] Next, the support substrate 4 will be described. As shown in Fig. 1, the support substrate 4 is fixed to the bottom surface of the first recess 211a by a bonding member B1. The support substrate 4 is located below the angular velocity sensing element 3 and supports the angular velocity sensing element 3 by lifting it up from below. The support substrate 4 is a substrate for TAB (Tape Automated Bonding) mounting, and as shown in Fig. 6, has a frame-shaped substrate 41, a plurality of leads 42 provided on the substrate 41, and a constant potential layer 43 located between the leads 42 and the angular velocity sensing element 3.

[0025] The substrate 41 is made of a film made of an insulating resin such as polyimide. However, the material of the substrate 41 is not particularly limited, and it can be made of, for example, an insulating resin other than polyimide. The substrate 41 is fixed to the bottom surface of the first recess 211a by a bonding member B1, and each lead 42 is electrically connected to the internal terminal 231 via this bonding member B1. The base 30 of the angular velocity sensing element 3 is fixed to the tip of each lead 42 by a bonding member B2, and each lead 42 is electrically connected to the terminals T1 to T6 via this bonding member B2. As a result, the angular velocity sensing element 3 is supported by the base 21 via the support substrate 4 and is electrically connected to the circuit element 5.

[0026] As shown in Fig. 6, the substrate 41 has a frame shape when viewed from above in the Z-axis direction, and has an opening 411 on the inside. The six leads 42 are bonding leads that support the angular velocity sensing element 3, and are conductive wiring patterns. In this embodiment, each lead 42 is made of metal foil such as copper foil. This makes it easy to form the leads 42.

[0027] Furthermore, three of the six leads 42 are arranged on the positive side of the X-axis direction with respect to the center of the substrate 41, and their tips extend into the opening 411 of the substrate 41. Of these three leads 42, the central lead 42 extends straight in the X-axis direction. In contrast, the two leads 42 located on both sides in the Y-axis direction are bent in a crank-like shape toward the center midway. Meanwhile, the remaining three leads 42 are arranged on the negative side of the X-axis direction with respect to the center of the substrate 41, and their tips extend into the opening 411 of the substrate 41. Of these three leads 42, the central lead 42 extends straight in the X-axis direction. In contrast, the two leads 42 located on both sides in the Y-axis direction are bent in a crank-like shape toward the center midway.

[0028] The base end of each lead 42 is disposed on the underside of the substrate 41 and is electrically connected to the corresponding internal terminal 231 via a bonding member B1. By disposing each lead 42 on the underside of the substrate 41 in this way, the distance between the lead 42 and the angular velocity sensing element 3 can be made larger than when the lead 42 is disposed on the surface of the substrate 41 facing the angular velocity sensing element 3, i.e., on the upper surface, as in a third embodiment described later. This makes it more difficult for an electrostatic coupling C to be formed.

[0029] Each lead 42 is bent midway in the Z-axis direction and tilted upward, with its tip passing through opening 411 and positioned above substrate 41, i.e., on the positive side in the Z-axis direction. The base 30 of angular velocity detecting element 3 is fixed to the upper surface of the tip of each lead 42 via bonding member B2. Although not shown, each lead 42 is electrically connected to a corresponding terminal T1 to T6 via bonding member B2.

[0030] The bonding members B1 and B2 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, and solder bumps, and conductive adhesives in which conductive fillers such as silver fillers are dispersed in various adhesives such as polyimide-based, epoxy-based, silicone-based, and acrylic-based adhesives can be used.

[0031] As shown in FIGS. 7 and 8 , the constant potential layer 43 is disposed on the upper surface of each lead 42 via an insulating layer 44 having insulating properties. Disposing the constant potential layer 43 on the upper surface of the lead 42 in this manner facilitates the formation of the constant potential layer 43. For example, in this embodiment, copper foil before patterning is prepared, an organic insulating material is applied to the upper surface of the copper foil, and the insulating layer 44 is formed by drying the material. Furthermore, a plating layer is formed on the upper surface of the insulating layer 44 by plating, thereby forming the constant potential layer 43. Finally, the copper foil is patterned to form the leads 42 on which the constant potential layer 43 is formed. This method facilitates the formation of the constant potential layer 43 on the leads 42. The constant potential layer 43 is disposed between each lead 42 and the angular velocity detection element 3 and functions as a shield that suppresses, and preferably prevents, electrostatic coupling C between them.

[0032] 9, a constant potential layer 43 is disposed in a frame shape on the underside of the substrate 41, and the portions disposed on the leads 42 are electrically connected via this portion. Although not shown, the portions disposed on the underside of the substrate 41 are electrically connected to the corresponding internal terminals 231 via bonding members B1. This configuration facilitates electrical connection between the constant potential layer 43 and the internal terminals 231. Furthermore, the constant potential layer 43 is electrically connected to the lid 22 via internal wiring (not shown) formed in the base 21. As described above, since the lid 22 is connected to ground when the angular velocity sensor 1 is in use, electrically connecting the constant potential layer 43 to the lid 22 allows the constant potential layer 43 and the lid 22 to be connected to ground. This simplifies the configuration of the angular velocity sensor 1.

[0033] However, without being limited thereto, the constant potential layer 43 may be connected to a constant potential when the angular velocity sensor 1 is in use, and may be electrically connected to, for example, the first and second detection ground electrodes E2 and E4 or the drive ground electrode E6. Furthermore, the constant potential to which the constant potential layer 43 is connected is not limited to ground, and may be, for example, the VDD potential for the circuit element 5.

[0034] 6, the constant potential layer 43 is not disposed at the tip of each lead 42. Therefore, the top surface of each lead 42 at the tip is exposed from the constant potential layer 43. This allows each lead 42 and the angular velocity sensing element 3 to be easily electrically connected via the bonding member B2 without being obstructed by the constant potential layer 43.

[0035] Next, the function of the constant potential layer 43 will be described in detail. As shown in FIG. 10, the lead 42 electrically connected to the first detection signal electrode E1 (hereinafter, this lead 42 will also be referred to as the "detection signal lead 42E1") passes across directly below the drive vibration arm 37 in a plan view from the Z-axis direction, and intersects with the drive signal electrode E5 in a region Q1. Therefore, for example, as shown in FIG. 11, if the constant potential layer 43 were not present, electrostatic coupling C would occur between the drive signal electrode E5 and the detection signal lead 42E1 at the intersection, and noise from the drive signal electrode E5 would be carried over the first detection signal propagating through the detection signal lead 42E1 via this electrostatic coupling C. In particular, the first detection signal is very weak, and the degradation of the S / N ratio due to noise contamination would be significant.

[0036] To address this issue, in the angular velocity sensor 1, a constant potential layer 43 is disposed on the upper surface of the detection signal lead 42E1 in an area overlapping with the drive signal electrode E5, as shown in Fig. 12. This positions the constant potential layer 43, which functions as a shield, between the drive signal electrode E5 and the detection signal lead 42E1. This effectively suppresses the electrostatic coupling C between the drive signal electrode E5 and the detection signal lead 42E1, making it difficult for noise from the drive signal electrode E5 to be carried over to the first detection signal propagating through the detection signal lead 42E1.

[0037] Similarly, as shown in FIG. 10, the lead 42 electrically connected to the second detection signal electrode E3 (hereinafter, this lead 42 will also be referred to as the "detection signal lead 42E3") passes across directly below the drive vibration arm 38 in a plan view from the Z-axis direction, and intersects with the drive signal electrode E5 in a region Q2. Therefore, for example, as shown in FIG. 13, if there is no constant potential layer 43, electrostatic coupling C occurs between the drive signal electrode E5 and the detection signal lead 42E3 at the intersection, and noise from the drive signal electrode E5 is carried over the second detection signal propagating through the detection signal lead 42E3 via this electrostatic coupling C. In particular, the second detection signal is very weak, similar to the first detection signal, and the degradation of the S / N ratio due to the inclusion of noise becomes significant.

[0038] 14, in the angular velocity sensor 1, a constant potential layer 43 is disposed on the upper surface of the detection signal lead 42E3 in an area overlapping with the drive signal electrode E5. This intervenes between the drive signal electrode E5 and the detection signal lead 42E3, providing the constant potential layer 43, which functions as a shield. This effectively suppresses the electrostatic coupling C between the drive signal electrode E5 and the detection signal lead 42E3, making it difficult for noise from the drive signal electrode E5 to be carried over to the second detection signal propagating through the detection signal lead 42E3.

[0039] As described above, the angular velocity sensor 1 of this embodiment can effectively suppress noise contamination of the first and second detection signals. Furthermore, even if the angular velocity sensor 1 is subjected to a mechanical shock and the lead 42 is deformed, the change in electrostatic capacitance between the drive signal electrode E5 and the detection signal leads 42E1 and 42E3 can be minimized. Therefore, the angular velocity sensor 1 can detect the angular velocity ωz with higher accuracy.

[0040] In this embodiment, the detection signal lead 42E1 crosses directly below the drive vibration arm 37, but is not limited to this and may be arranged to cross directly below the drive vibration arm 35, for example. Similarly, in this embodiment, the detection signal lead 42E3 crosses directly below the drive vibration arm 38, but is not limited to this and may be arranged to cross directly below the drive vibration arm 36, for example. With such a configuration, it is possible to achieve the same effect as this embodiment.

[0041] 6, 7, and 8, in this embodiment, the constant potential layer 43 is also disposed on all leads 42 except for the detection signal leads 42E1 and 42E3. However, this is not limited to this. For example, as shown in FIG. 15, the constant potential layer 43 may be disposed only on the detection signal leads 42E1 and 42E3. However, disposing the constant potential layer 43 on all leads 42 as in this embodiment makes it easier to manufacture the support substrate 4. Furthermore, by disposing the constant potential layer 43 on all leads 42, the constant potential layer 43 increases the rigidity of all leads 42 in a balanced manner. Therefore, the angular velocity detection element 3 can be supported by the support substrate 4 in a more stable position.

[0042] [Circuit element 5] Next, the circuit element 5 will be described. As shown in FIG. 1, the circuit element 5 is fixed to the bottom surface of the third recess 211c via a fixing member such as metal paste or adhesive. The circuit element 5 is also electrically connected to the angular velocity sensing element 3 via the support substrate 4. The circuit element 5 includes a drive circuit 51 that applies a drive signal to drive the angular velocity sensing element 3, and a detection circuit 52 that performs detection processing of the angular velocity ωz based on the first and second detection signals from the angular velocity sensing element 3.

[0043] The angular velocity sensor 1 has been described above. As described above, the angular velocity sensor 1 includes the angular velocity detection element 3 having the drive vibration arms 37, 38 on which the drive signal electrode E5 to which a drive signal is applied is arranged, and the detection vibration arms 31, 32 on which the first and second detection signal electrodes E1, E3 are arranged as detection signal electrodes that output first and second detection signals, which are detection signals; the support substrate 4 having a plurality of leads 42 supporting the angular velocity detection element 3 and a substrate 41 supporting the plurality of leads 42. The plurality of leads 42 also include detection signal leads 42E1, 42E3 electrically connected to the first and second detection signal electrodes E1, E3. In a plan view of the support substrate 4, the detection signal leads 42E1, 42E3 overlap the drive signal electrode E5, and a constant potential layer 43 is arranged between the detection signal leads 42E1, 42E3 and the drive signal electrode E5. With this configuration, electrostatic coupling between the detection signal leads 42E1, 42E3 and the drive signal electrode E5 can be effectively suppressed by the constant potential layer 43. As a result, noise from the drive signal electrode E5 is less likely to be carried over to the first and second detection signals, and the angular velocity ωz can be detected with higher accuracy.

[0044] As described above, the constant potential layer 43 is disposed on the surfaces of the detection signal leads 42E1 and 42E3 facing the angular velocity detection element 3, i.e., on the upper surfaces, via the insulating layer 44. This configuration makes it easy to form the constant potential layer 43.

[0045] As described above, the leads 42 are arranged on the surface of the substrate 41 opposite to the angular velocity sensing element 3, i.e., on the lower surface. With this configuration, the distance between the leads 42 and the angular velocity sensing element 3 can be made larger than when the leads 42 are arranged on the upper surface of the substrate 41, as in a fourth embodiment described later. This makes it difficult for electrostatic coupling C to be formed between the leads 42 and the angular velocity sensing element 3.

[0046] As described above, the device also includes the base 21 having the recess 211 and supporting the angular velocity sensing element 3 via the support substrate 4, and the lid 22 joined to the base 21 so as to close the opening of the recess 211. With this configuration, the angular velocity sensing element 3 can be protected.

[0047] As described above, the lid 22 is connected to the ground, and the constant potential layer 43 is electrically connected to the lid 22. With this configuration, the constant potential layer 43 can be connected to the ground, which is at a constant potential, with a simple configuration and more reliably.

[0048] Second Embodiment Fig. 16 and Fig. 17 are cross-sectional views of the support substrate according to the second embodiment. Fig. 16 corresponds to the cross-sectional view of Fig. 7, and Fig. 17 corresponds to the cross-sectional view of Fig. 8.

[0049] The angular velocity sensor 1 of this embodiment is the same as that of the first embodiment described above, except for the configuration of the support substrate 4, specifically, the arrangement of the constant potential layer 43. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and a description of the same points will be omitted. In addition, in each drawing of this embodiment, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0050] 16 and 17, in the support substrate 4 of this embodiment, the width W1 of the constant potential layer 43 is larger than the width W2 of the leads 42, and the constant potential layer 43 is disposed so as to extend beyond both sides of the leads 42 in the Y-axis direction. This allows a wider area to be covered above each lead 42, more effectively suppressing the formation of electrostatic coupling C. This further reduces the likelihood of noise being introduced into the first and second detection signals. This allows the angular velocity ωz to be detected with even greater accuracy.

[0051] The second embodiment can also achieve the same effects as the first embodiment described above.

[0052] <Third embodiment> Fig. 18 is a top view of a support substrate according to a third embodiment. Fig. 19 is a cross-sectional view taken along line CC in Fig. 18. Fig. 20 is a cross-sectional view for explaining the effect of the support substrate shown in Fig. 18. Figs. 21 and 22 are cross-sectional views showing modified examples of the support substrate.

[0053] The angular velocity sensor 1 of this embodiment is the same as that of the first embodiment described above, except for the configuration of the support substrate 4, specifically, the arrangement of the constant potential layer 43. In the following description, the differences between this embodiment and the previous embodiment will be mainly described, and a description of the same points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0054] 18 and 19, in the support substrate 4 of this embodiment, the constant potential layer 43 is disposed on the upper surface of the substrate 41, that is, on the surface on the angular velocity detection element 3 side. By disposing the constant potential layer 43 on the upper surface of the substrate 41 in this way, the constant potential layer 43 can be disposed closer to the drive signal electrode E5 than in the first embodiment described above, for example, as shown in Fig. 20. This further enhances the shielding effect provided by the constant potential layer 43, and more effectively suppresses the formation of electrostatic coupling C.

[0055] 18, the constant potential layer 43 is formed in a frame shape and collectively covers the top of all the leads 42. This facilitates the formation of the constant potential layer 43. Furthermore, since a wider area above the leads 42 can be covered, the shielding effect becomes more pronounced.

[0056] In this embodiment, the constant potential layer 43 is disposed on the upper surface of the substrate 41, and therefore, although not shown, the constant potential layer 43 is electrically connected to the internal terminal 231 by a bonding wire, not by the bonding member B1. This facilitates electrical connection between the constant potential layer 43 and the internal terminal 231.

[0057] As described above, in the angular velocity sensor 1 of this embodiment, the leads 42 are arranged on the surface of the substrate 41 opposite the angular velocity detection element 3, i.e., the lower surface, and the constant potential layer 43 is arranged on the surface of the substrate 41 facing the angular velocity detection element 3, i.e., the upper surface. With this configuration, the distance between the leads 42 and the angular velocity detection element 3 can be increased compared to, for example, a fourth embodiment described later, in which the leads 42 are arranged on the upper surface of the substrate 41. This makes it difficult for electrostatic coupling C to be formed between the leads 42 and the angular velocity detection element 3. Furthermore, the constant potential layer 43 can be arranged closer to the drive signal electrode E5 than, for example, the first embodiment described above. This further enhances the shielding effect of the constant potential layer 43, thereby more effectively suppressing the formation of electrostatic coupling C.

[0058] The third embodiment can also achieve the same effects as the first embodiment. For example, as shown in FIGS. 21 and 22, the constant potential layer 43 may be divided and formed for each lead 42. This configuration can also achieve the same effects. While only the three leads 42 located on the negative side in the X-axis direction are shown in FIGS. 21 and 22, the same applies to the three leads 42 located on the positive side in the X-axis direction. The constant potential layer 43 covering the tops of the leads 42 other than the detection signal leads 42E1 and 42E3 may be omitted.

[0059] <Fourth embodiment> Fig. 23 is a top view of a support substrate according to a fourth embodiment, and Fig. 24 is a cross-sectional view taken along line DD in Fig. 23 .

[0060] The angular velocity sensor 1 of this embodiment is the same as that of the first embodiment described above, except for the configuration of the support substrate 4, specifically, the arrangement of the constant potential layer 43. In the following description, the differences between this embodiment and the previous embodiment will be mainly described, and a description of the same points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0061] 23 and 24, in the support substrate 4 of this embodiment, each lead 42 is disposed on the upper surface of the substrate 41. A constant potential layer 43 is disposed on the upper surface of each lead 42 with an insulating layer 44 interposed therebetween. With this configuration, it is possible to support the angular velocity sensing element 3 while avoiding contact with the substrate 41, even without bending each lead 42 in the Z-axis direction midway and tilting it upward as in the first embodiment. This makes it easier to form the support substrate 4. It is also possible to prevent a decrease in the mechanical strength of the leads 42 due to bending.

[0062] In this embodiment, each lead 42 arranged on the upper surface of the substrate 41 is drawn out to the lower surface of the substrate 41. Then, although not shown, the portion arranged on the lower surface of the substrate 41 is electrically connected to the internal terminal 231 by a bonding member B1. This facilitates electrical connection between each lead 42 and the internal terminal 231. On the other hand, the constant potential layer 43 is electrically connected to the internal terminal 231 via, for example, a bonding wire. However, the electrical connection method is not particularly limited.

[0063] As described above, in the angular velocity sensor 1 of this embodiment, the multiple leads 42 are arranged on the surface of the substrate 41 facing the angular velocity sensing element 3, i.e., on the upper surface. With this configuration, it is possible to support the angular velocity sensing element 3 while avoiding contact with the substrate 41, even without bending each lead 42 in the Z-axis direction midway and tilting it upward, as in the first embodiment. This makes it easier to form the support substrate 4. It is also possible to prevent a decrease in the mechanical strength of the leads 42 due to bending.

[0064] The fourth embodiment can also achieve the same effects as the first embodiment described above.

[0065] Although the angular velocity sensor of the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this. The configuration of each part can be replaced with any configuration having a similar function. Furthermore, any other configuration may be added to the present invention. [Explanation of symbols]

[0066] 1...Angular velocity sensor, 2...Package, 21...Base, 211...Recess, 211a...First recess, 211b...Second recess, 211c...Third recess, 22...Lid, 221...Groove, 23...Seam ring, 231...Internal terminal, 232...Internal terminal, 233...External terminal, 3...Angular velocity detection element, 30...Base, 31...Detection vibration arm, 32...Detection vibration arm, 33...Support arm, 34...Support arm, 35...Driving vibration arm, 36...Driving vibration arm, 37...Driving vibration arm, 38...Driving vibration arm, 4...Support substrate, 41...Substrate, 411...Opening, 42...Lead, 42E1...Lead for detection signal, 42E3...detection signal lead, 43...constant potential layer, 44...insulating layer, 5...circuit element, 51...drive circuit, 52...detection circuit, B1...bonding member, B2...bonding member, BW...bonding wire, C...electrostatic coupling, E1...first detection signal electrode, E2...first detection ground electrode, E3...second detection signal electrode, E4...second detection ground electrode, E5...drive signal electrode, E6...drive ground electrode, EL...energy line, Q1...region, Q2...region, S...internal space, T1...terminal, T2...terminal, T3...terminal, T4...terminal, T5...terminal, T6...terminal, ωz...angular velocity, W1...width, W2...width

Claims

1. an angular velocity detection element having a drive vibration arm in which a drive signal electrode to which a drive signal is applied is arranged, and a detection vibration arm in which a detection signal electrode that outputs a detection signal is arranged; a support substrate having a plurality of leads supporting the angular velocity detection element and a substrate supporting the plurality of leads; the plurality of leads include a detection signal lead electrically connected to the detection signal electrode, the detection signal leads overlap the drive signal electrodes in a plan view of the support substrate; An angular velocity sensor characterized in that a constant potential layer is disposed between the detection signal lead and the drive signal electrode.

2. 2. The angular velocity sensor according to claim 1, wherein the constant potential layer is disposed on a surface of the detection signal lead on the angular velocity detection element side via an insulating layer.

3. The angular velocity sensor according to claim 2 , wherein the leads are arranged on a surface of the substrate facing the angular velocity detection element.

4. 3. The angular velocity sensor according to claim 2, wherein the leads are arranged on a surface of the substrate opposite to the surface on which the angular velocity detection element is disposed.

5. the plurality of leads are arranged on a surface of the substrate opposite to the angular velocity detection element, 2. The angular velocity sensor according to claim 1, wherein the constant potential layer is disposed on a surface of the substrate facing the angular velocity detection element.

6. a base having a recess and supporting the angular velocity sensing element via the support substrate; 2. The angular velocity sensor according to claim 1, further comprising: a lid joined to the base so as to close the opening of the recess.

7. the lid is connected to ground; The angular velocity sensor according to claim 6 , wherein the constant potential layer is electrically connected to the lid.

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