Vibrator device

A vibrator device includes a vibrating body having a first surface, a package having a second surface opposed to the first surface of the vibrating body, a circuit board provided to the package so as to be opposed to the first surface of the vibrating body, a plurality of coupling electrodes provided to the first surface of the vibrating body, a first coupling line provided to the second surface of the package, a second coupling line provided to the circuit board, and a bonding material electrically coupling the coupling electrode and the first coupling line to each other, wherein the vibrating body has a protrusion protruding toward the package farther than the coupling electrode at the first surface side, and the protrusion has contact with the second surface of the package.

The present application is based on, and claims priority from JP Application Serial Number 2020-009799, filed Jan. 24, 2020, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a vibrator device.

2. Related Art

In JP-A-2018-159674, there is disclosed a vibrator device which has a vibrator element, a relay substrate for supporting the vibrator element, and a package for fixing the relay substrate, and in which fixation parts provided to both ends of the relay substrate are fixed with an adhesive to an upper stage surface provided to a base member of the package to thereby reduce transmission of a thermal stress occurring in the package or a stress caused by an impact or the like received by the package to the vibrator element to reduce a variation of the vibration characteristics.

However, in the vibrator device described in Document 1, there is a possibility that the distance between the relay substrate and the package varies due to the variation in thickness of the adhesive when installing the relay substrate in the package. Therefore, there is a problem that capacitances occurring between electrode lines on the relay substrate and wiring lines in the package, and between the electrode lines on the relay substrate and wiring lines of a circuit board varies, and it is difficult to achieve a design taking the capacitances into consideration.

SUMMARY

A vibrator device includes a vibrating body having a first surface, a package having a second surface opposed to the first surface of the vibrating body, a circuit board provided to the package so as to be opposed to the first surface of the vibrating body, a plurality of coupling electrodes provided to the first surface of the vibrating body, a first coupling line provided to the second surface of the package, a second coupling line provided to the circuit board, and a bonding material electrically coupling the coupling electrode and the first coupling line to each other, wherein the vibrating body has a protrusion protruding toward the package farther than the coupling electrode at the first surface side, and the protrusion has contact with the second surface of the package.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

1. First Embodiment

First, a vibrator device1according to a first embodiment will be described with reference toFIG.1throughFIG.7citing a vibrator device having the vibrating body having the vibrator element mounted on the support substrate as an example.

It should be noted that an X axis, a Y axis, and a Z axis in the drawings are axes perpendicular to each other, wherein a direction extending along the X axis is defined as an “X direction,” a direction extending along the Y axis is defined as a “Y direction,” and a direction extending along the Z axis is defined as a “Z direction,” and directions with arrows are positive directions. Further, the description will be presented defining the positive direction in the Z direction as an “upper side,” and the negative direction in the Z direction as a “lower side.” Further, inFIG.1, a plan view seen through a lid22is used for the sake of convenience of explanation. Further, inFIG.1andFIG.2, wiring lines and electrodes provided to a support substrate4and a vibrator element6are omitted from the illustration.

The vibrator device1according to the present embodiment is a physical quantity sensor for detecting angular velocity ωz defining the Z axis as the detection axis. As shown inFIG.1,FIG.2, andFIG.3, the vibrator device1has a package2, and a vibrating body5and a circuit element3as a circuit board housed in the package2. It should be noted that the vibrating body5includes the support substrate4and the vibrator element6, wherein the vibrator element6is supported on the support substrate4.

The package2has a base21provided with a recessed part24opening in an upper surface, and the lid22which is bonded to an upper surface of a base21via a bonding member23so as to close the opening of the recessed part24. The recessed part24forms an internal space S inside the package2, and the vibrating body5and the circuit element3are housed in the internal space S. For example, the base21can be formed of ceramics such as alumina, and the lid22can be formed of a metal material such as kovar. It should be noted that the constituent materials of the base21and the lid22are not particularly limited.

The internal space S is airtightly sealed, and is set in a reduced-pressure state, and more preferably a state approximate to a vacuum state. Thus, the viscosity resistance reduces and the vibration characteristics of the vibrator element6are improved. It should be noted that the atmosphere in the internal space S is not particularly limited, but can be, for example, in the atmospheric pressure state or a pressurized state.

Further, the recessed part24is constituted by a plurality of recessed parts24a,24b, and24carranged side by side in the Z direction, and has the recessed part24aopening in the upper surface of the base21, the recessed part24bwhich opens in a bottom surface of the recessed part24aand is smaller in opening width than the recessed part24a, and the recessed part24cwhich opens in a bottom surface of the recessed part24band is smaller in opening width than the recessed part24b. Further, to a second surface2aas the bottom surface of the recessed part24a, there is fixed the support substrate4for the vibrating body5, and to the bottom surface of the recessed part24c, there is fixed the circuit element3.

Further, on the second surface2aof the recessed part24a, there is disposed internal terminals25as a plurality of first coupling lines, on the bottom surface of the recessed part24b, there is disposed a plurality of internal terminals26, and on the lower surface of the base21, there is disposed a plurality of external terminals27. The internal terminals25,26and the external terminals27described above are electrically coupled to each other via wiring lines not shown formed inside the base21. Further, as shown inFIG.3, the internal terminals25are electrically coupled to terminals49as coupling electrodes provided to the support substrate4via bonding materials51having electrical conductivity. Further, the internal terminals26are electrically coupled to terminals31as second coupling lines disposed on the circuit element3via bonding wires53.

The circuit element3is fixed to the bottom surface of the recessed part24c. The circuit element3includes a drive circuit for driving the vibrator element6and a detection circuit for detecting the angular velocity ωz applied to the vibrator element6.

As shown inFIG.3, in the vibrator device1, the terminals49provided to a first surface4aof the support substrate4are fixed with the adhesive on the internal terminals25provided to the second surface2aof the recessed part24avia bonding materials51such as electrically-conductive adhesive. Further, the first surface4aat both ends in the X direction of the support substrate4is provided with a plurality of protrusions48each protruding toward the package2farther than the terminals49, and a surface48aof each of the protrusions48opposed to the second surface2aof the recessed part24ahas contact with the second surface2aof the recessed part24aconstituting the package2. It should be noted that the surface48ahaving contact with the second surface2aof the protrusion48is parallel to the second surface2a.

Further, since the plurality of protrusions48is disposed along sides50at both ends of the support substrate4, by fixing with the adhesive the support substrate4and the recessed part24aof the package2to each other in the state in which the surfaces48aof the protrusions48have contact with the second surface2aof the recessed part24a, the protrusions48function as a stopper, and thus, the distance between the first surface4aof the support substrate4and the bottom surface of the recessed part24in the package2can be made constant. Therefore, the capacitances formed between the plurality of terminals49provided to the first surface4aof the support substrate4and the internal terminals25provided to the bottom surface of the recessed part24ain the package2, and between a plurality of wiring lines9described later and provided to a surface at an opposite side to the first surface4aof the support substrate4and terminals31of the circuit element3mounted on the bottom surface of the recessed part24cin the package2can be made constant, and it becomes easy to achieve the design taking the capacitances into consideration.

The vibrating body5includes the vibrator element6and the support substrate4disposed between the vibrator element6and the package2, and supports the vibrator element6on the support substrate4via the bonding material52as shown inFIG.2.

The vibrator element6is an angular velocity sensor element capable of detecting the angular velocity ωz defining the Z axis as the detection axis as the physical quantity sensor element. As shown inFIG.4, the vibrator element6has a vibrating substrate7, and electrodes8disposed on a surface of the vibrating substrate7. The vibrating substrate7is formed of a Z-cut quartz crystal substrate. The Z-cut quartz crystal substrate has spread in an X-Y plane defined by an X axis as an electrical axis and a Y axis as a mechanical axis, and has a thickness in a direction along a Z axis as an optical axis, wherein the electrical axis, the mechanical axis, and the optical axis are crystal axes of quartz crystal.

The vibrating substrate7has a base part70located in a central portion, detection arms71,72as a pair of detection parts extending toward both sides in the Y direction from the base part70, a pair of coupling arms73,74extending toward both sides in the X direction from the base part70, drive arms75,76as a pair of drive parts extending toward both sides in the Y direction from a tip part of the coupling arm73, and drive arms77,78as a pair of drive parts extending toward both sides in the Y direction from a tip part of the coupling arm74.

As shown inFIG.4, the electrodes8include drive electrodes81, drive ground electrodes82, first detection electrodes83as detection electrodes, first detection ground electrodes84, second detection electrodes85as the detection electrodes, and second detection ground electrodes86.

The drive electrodes81are disposed on both side surfaces of each of the drive arms75,76, and an upper surface and a lower surface of each of the drive arms77,78. Meanwhile, the drive ground electrodes82are disposed on an upper surface and a lower surface of each of the drive arms75,76, and both side surfaces of each of the drive arms77,78. Further, the first detection electrodes83are disposed on an upper surface and a lower surface of the detection arm71, and the first detection ground electrodes84are disposed on both side surfaces of the detection arm71. Meanwhile, the second detection electrodes85are disposed on an upper surface and a lower surface of the detection arm72, and the second detection ground electrodes86are disposed on both side surfaces of the detection arm72.

Further, these electrodes81through86are each laid around to a lower surface of the base part70. Further, as shown inFIG.4, on the lower surface of the base part70, there are disposed a terminal61electrically coupled to the drive electrodes81, a terminal62electrically coupled to the drive ground electrodes82, a terminal63electrically coupled to the first detection electrodes83, a terminal64electrically coupled to the first detection ground electrodes84, a terminal65electrically coupled to the second detection electrodes85, and a terminal66electrically coupled to the second detection ground electrodes86.

Such a vibrator element6detects the angular velocity ωz in the following manner. First, when applying a drive signal between the drive electrodes81and the drive ground electrodes82, the drive arms75through78flexurally vibrate as represented by the arrows shown inFIG.5. Hereinafter, this drive mode is referred to as a drive vibration mode. Further, when the angular velocity ωz is applied to the vibrator element6in the state of performing the drive in the drive vibration mode, a detection vibration mode shown inFIG.6is newly excited. In the detection vibration mode, a Coriolis force acts on the drive arms75through78to excite the vibration in a direction represented by the arrows b, and in concert with this vibration, the detection vibration due to the flexural vibration occurs in a direction represented by the arrows a in the detection arms71,72. A charge generated in the detection arm71due to such a detection vibration mode is taken out between the first detection electrodes83and the first detection ground electrodes84as a first detection signal, a charge generated in the detection arm72is taken out between the second detection electrodes85and the second detection ground electrodes86as a second detection signal, and it is possible to detect the angular velocity ωz based on these first and second detection signals.

The support substrate4is formed of the quartz crystal substrate with the same cutting angle as that in the vibrating substrate7. The support substrate4has a gimbal structure, and has an element mount part41, a support part42, a frame part43, a pair of inner beam parts44,45, and a pair of outer beam parts46,47, wherein the vibrator element6is mounted on the element mount part41, the support part42is located outside the element mount part41, fixed to the base21, and has a frame-like shape, the frame part43is located between the element mount part41and the support part42, and has a frame-like shape surrounding the element mount part41, the pair of inner beam parts44,45extend toward both sides in the X direction from the element mount part41to couple the element mount part41and the frame part43to each other, and the pair of outer beam parts46,47extend toward both sides in the Y direction from the frame part43to couple the frame part43and the support part42to each other in a plan view from the Z direction as shown inFIG.7.

Further, the support substrate4has the plurality of protrusions48protruding toward the negative Z direction at the first surface4aside of both ends in the X direction of the support part42. The plurality of protrusions48is disposed along the sides50at the both ends of the support part42between the terminals49as the plurality of coupling electrodes.

Further, the support substrate4is provided with a plurality of wiring lines9electrically coupling the electrodes81through86of the vibrator element6and the internal terminals25in the package2to each other. The plurality of wiring lines9includes a drive wiring line91and a drive ground wiring line92as a drive wiring line, a first detection wiring line93as a detection wiring line, a first detection ground wiring line94, a second detection wiring line95as a detection wiring line, a second detection ground wiring line96, and the terminals49. Therefore, the support substrate4is provided with two driving wiring lines, four detecting wiring lines, and six terminals used for coupling to the internal terminals25in the package2. Further, these wiring lines91through96are each laid around to the element mount part41and the support part42through the inner beam parts44,45, the frame part43, and the outer beam parts46,47. It should be noted that the wiring lines9correspond to the coupling electrodes in the present embodiment.

Further, the drive wiring line91is electrically coupled to the terminal61, namely the drive electrodes81, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42. Further, the drive ground wiring line92is electrically coupled to the terminal62, namely the drive ground electrodes82, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42.

Further, the first detection wiring line93is electrically coupled to the terminal63, namely the first detection electrodes83, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42. Further, the first detection ground wiring line94is electrically coupled to the terminal64, namely the first detection ground electrodes84, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42.

Further, the second detection wiring line95is electrically coupled to the terminal65, namely the second detection electrodes85, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42. Further, the second detection ground wiring line96is electrically coupled to the terminal66, namely the second detection ground electrodes86, via the bonding material52on the element mount part41, and is electrically coupled to the internal terminal25via the bonding material51in the terminal49disposed in the end part of the support part42.

Thus, the vibrator element6and the circuit element3are electrically coupled to each other via these wiring lines91through96. It should be noted that the bonding materials51,52are not particularly limited providing both of the electrical conductivity and the bonding property are provided, and there can be used, for example, an electrically-conductive adhesive, or a variety of types of metal bumps such as a gold bump or a solder bump.

Among the six wiring lines91through96, the drive wiring line91, the first detection ground wiring line94, and the second detection ground wiring line96are each laid around from the element mount part41to the terminal49disposed in the end part of the support part42through the inner beam part44, the frame part43, and the outer beam part46. Further, the drive ground wiring line92, the first detection wiring line93, and the second detection wiring line95are each laid around from the element mount part41to the terminal49disposed in the end part of the support part42through the inner beam part45, the frame part43, and the outer beam part47. It should be noted that the terminal49provided to the first surface4aof the support substrate4and the terminal49provided to the surface at the opposite side to the first surface4a, namely an upper surface of the support substrate4, are electrically coupled to each other with a side surface electrode provided to the side surface of the support substrate4.

In the vibrator device1according to the present embodiment, the first surface4aopposed to the package2at both ends of the support substrate4supporting the vibrator element6is provided with the plurality of protrusions48each protruding toward the package2farther than the terminals49, and the surface48aof each of the protrusions48opposed to the second surface2aof the recessed part24ahas contact with the second surface2aof the recessed part24aconstituting the package2. Therefore, by fixing with the adhesive the support substrate4and the recessed part24aof the package2, the protrusions48function as the stopper, and the distance between the first surface4aof the support substrate4and the bottom surface of the recessed part24in the package2can be made constant. Therefore, the capacitances formed between the coupling electrodes such as the plurality of terminals49provided to the first surface4aof the support substrate4and the first coupling lines such as the internal terminals25provided to the bottom surface of the recessed part24ain the package2, and between the coupling electrodes such as the plurality of wiring lines9provided to the surface at the opposite side to the first surface4aof the support substrate4and the second coupling lines such as the terminals31of the circuit element3mounted on the bottom surface of the recessed part24cin the package2can be made constant, and it is possible to make it easy to achieve the design taking the capacitances into consideration.

Further, since the protrusions48are provided along the sides50at the both ends of the support substrate4, and are disposed between the terminals49, the support substrate4can be made parallel to the recessed part24in the package2in both of the X direction and the Y direction, namely the distance between the first surface4aof the support substrate4and the bottom surface of the recessed part24in the package2can be made constant in both of the directions. Therefore, it is possible to further reduce the variation of the capacitances.

Further, since the surfaces48ahaving contact with the second surface2aof the protrusions48are parallel to the second surface2a, the distance between the bottom surface of the recessed part24in the package2and the first surface4aof the support substrate4can be made more constant and it is possible to further reduce the variation of the capacitances.

Further, since at least one of the terminals49is the drive wiring line91electrically coupled to the drive electrodes81, and at least one of the terminals49is one of the detection wiling lines93,95electrically coupled respectively to the detection electrodes83,85, it is possible to detect the angular velocity ωz by driving the drive parts of the vibrator element6with the circuit element3in the package2and then processing the detection signal output from the detection parts with the circuit element3.

2. Second Embodiment

Then, a vibrator device1aaccording to a second embodiment will be described with reference toFIG.8andFIG.9. It should be noted thatFIG.8andFIG.9correspond to apart located at the positive Y direction side and the negative X direction side out of the four corners inside the package2inFIG.1.

The vibrator device1aaccording to the present embodiment is substantially the same as the vibrator device1according to the first embodiment except the fact that a structure of protrusions480aof a support substrate40ais different compared to the vibrator device1according to the first embodiment. It should be noted that the description will be presented with a focus on the difference from the first embodiment described above, and the description of substantially the same issues will be omitted.

As shown inFIG.8andFIG.9, the protrusions480aprovided to the support substrate40aof the vibrator device1aare disposed along the side50of the support substrate40a, and each have a rectangular shape having long sides in the Y direction, and each protrude toward the negative Z direction. Further, the protrusion480ais disposed between the side50, and the internal terminal25and the terminal49bonded to each other with the bonding material51. It should be noted that the protrusion480ais also disposed between the side50, and the internal terminal25and the terminal49in the end part at the positive X direction side of the support substrate40a.

By adopting such a configuration, there can be obtained substantially the same advantages as those of the vibrator device1according to the first embodiment.

Then, a vibrator device1baccording to a third embodiment will be described with reference toFIG.10andFIG.11. It should be noted thatFIG.10andFIG.11correspond to a part located at the positive Y direction side and the negative X direction side out of the four corners inside the package2inFIG.1similarly toFIG.8andFIG.9described above.

The vibrator device1baccording to the present embodiment is substantially the same as the vibrator device1according to the first embodiment except the fact that a structure of a protrusion480bof a support substrate40bis different compared to the vibrator device1according to the first embodiment. It should be noted that the description will be presented with a focus on the difference from the first embodiment described above, and the description of substantially the same issues will be omitted.

As shown inFIG.10andFIG.11, the protrusions480bprovided to the support substrate40bof the vibrator device1beach have a rectangular shape having long sides in the Y direction, and each protrude toward the negative Z direction. Further, the protrusions480bare disposed along the side50of the support substrate40bat both sides in the X direction of the internal terminal25and the terminal49bonded to each other with the bonding material51. In other words, two protrusions480bare disposed along the side50across the internal terminal25and the terminal49. It should be noted that the two protrusions480bare also disposed across the internal terminal25and the terminal49in the end part at the positive X direction side of the support substrate40b.

By adopting such a configuration, there can be obtained substantially the same advantages as those of the vibrator device1according to the first embodiment.