JP2009103715A - System and structure for supporting vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel system for supporting a vibrator having a terminal for electrical connection so that the vibrator may be miniaturized and the deviation of vibration properties among vibrators mounted on the supporting systems may be prevented. <P>SOLUTION: The supporting system has a substrate 11 and bonding wires 9 and 10 supported on the substrate 11 and to be joined with a vibrator 1. The bonding wires are electrically connected with a terminal 6 of the vibrator 1. The vibrator 1 is supported with the bonding wires so that the vibrator 1 does not directly contact the substrate 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibrator support device and a support structure.

  The use of a vibratory gyroscope has been studied for a rotational speed sensor used in a vehicle control method of an automobile body rotational speed feedback type. In such a system, the direction of the steering wheel itself is detected by the rotation angle of the steering wheel. At the same time, the rotational speed at which the vehicle body is actually rotating is detected by the vibration gyroscope. Then, the direction of the steering wheel is compared with the actual rotational speed of the vehicle body to obtain a difference, and based on this difference, correction is made to the wheel torque and the steering angle, thereby realizing stable vehicle body control.

In a vehicle body control system, a vibratory gyroscope and its vibrator are exposed to a wide range of environmental temperatures, that is, high and low temperatures. Such a use temperature range usually extends over a range of −40 ° C .− + 85 ° C., and a more severe specification may cover a wider temperature range. In particular, when the vibrator is formed of a piezoelectric single crystal, there is an influence of temperature characteristics of the piezoelectric single crystal. In Patent Document 1, when the environmental temperature of the vibration-type gyroscope changes, the applicant of the present application uses an adhesive tan δ for bonding the vibrator to the support member in order to suppress variation in the Q value of the detected vibration. In the operating temperature range, 0.1 or less was disclosed.
Japanese Patent Laid-Open No. 2001-12955

  The present inventor has been researching mass production of a structure in which a piezoelectric single crystal vibrator is bonded and fixed on a support member. In this process, the following problem has been found. That is, in order to manufacture a support structure for a vibrator, typically, the vibrator is bonded to a pin-like or flat plate-like support member. For this purpose, a liquid adhesive composition needs to be poured between the vibrator and the support member and cured. Next, an adhesive such as silver paste is poured between the support member and the surface of the base of the package, and is cured by heat treatment. Thereby, the vibrator and the support member can be bonded to the base of the package. As an adhesive to the support member of the vibrator, for example, a silicone resin adhesive is preferable.

  However, new problems have arisen with recent technological advances. That is, the present inventor has been studying downsizing the vibrator and its mounting structure in order to make the package thinner. For example, in order to incorporate a vibration-type gyroscope in an image capturing device of a mobile phone, an ultra-small package is required.

  However, if the support member of the vibrator is a thin flat plate and the thickness is 0.5 mm or less, further 0.3 mm or less, various problems have arisen. For example, when a liquid adhesive composition is poured between a vibrator and a flat support member and cured, the adhesive surface becomes small, and the volume of the adhesive composition to be used becomes very small. It becomes difficult to adjust the total amount and area uniformly. Also, dripping of the adhesive and unnecessary wraparound easily occur, and it becomes difficult to control the shape and capacity of the adhesive layer as a whole. If the shape and capacity of the adhesive layer of the vibrator become non-uniform, or if dripping or unnecessary wraparound occurs, the overall physical properties of the adhesive layer change, and as a result, the vibration characteristics of the vibrator change. In particular, in the case of a vibrating gyroscope, the output signal from the detection electrode on the vibrator is a signal representing the rotational angular velocity. For this reason, when the vibration characteristics of the vibrator change, noise increases and it becomes difficult to obtain a correct value of the rotational angular velocity.

  An object of the present invention is a support device for supporting a vibrator having a terminal portion for electrical connection, the vibrator can be miniaturized, and the vibrator of each support device It is an object of the present invention to provide a novel support device that can suppress fluctuations in vibration characteristics.

The present invention is a support device for supporting a vibrator having a terminal portion for electrical connection, and includes a substrate and a bonding wire supported on the substrate and to be bonded to the vibrator. And the vibrator is configured to be supported by the bonding wire without contacting the substrate, and the bonding wire is electrically connected to the terminal portion.
The present invention also relates to a support structure for a vibrator, comprising the support device and a vibrator supported by the support device.

  The inventor paid attention to a bonding wire for supplying an electric signal to the terminal portion of the vibrator or transmitting a predetermined electric signal from the terminal portion of the vibrator to the package substrate. Then, the inventors have conceived that a bonding wire fixed on the substrate is bonded to the vibrator, and the vibrator is supported in a state of floating from the substrate. By downsizing the vibrator, the structural strength necessary to support the vibrator in a floating state can be obtained by the bonding wire. According to such a support structure, it is possible to suppress deviations and fluctuations in the vibration state of each vibrator.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is an exploded perspective view of a support structure of the present invention, FIG. 2 is a plan view showing a substrate 11 used in this embodiment, and FIG. 3 shows a frame 7 fixed on the substrate 11 and It is a top view which shows the bonding wires 9 and 10, FIG. 4 is a top view which shows the support structure of a present Example.

  As shown in FIG. 2, contact pads 12A and 12B are provided on the mounting surface 11a of the substrate 11 of this example. As shown in FIG. 3, the frame 7 is installed on the mounting surface 11a. The frame body 7 in this example is made of an insulating material. The frame body 7 includes an outer frame 7a and an auxiliary support portion 7b that protrudes inward from the outer frame 7a. A gap 8 is formed inside the frame body 7, and the mounting surface 11 a of the substrate 11 is exposed from the gap 8. The ends 9a and 10a of the bonding wires 9 and 10 are joined and fixed on the outer frame 7a. The end portions 9a and 10a are electrically connected to the corresponding contact pads 12A and 12B, respectively. Elongated main bodies 9b and 10b extend from end portions 9a and 10a of the bonding wires 9 and 10, respectively. The main body 9a is supported on the auxiliary support portion 7b.

  Next, the vibrator 1 is mounted as shown in FIG. As shown in FIGS. 1 and 4, the vibrator 1 of this example includes a fixed portion 2, a pair of detection vibrating pieces 3 protruding from the fixed portion 2, and a pair of support portions 5 protruding from the fixed portion 2, And a drive vibration piece 4 provided at the tip of the support portion 5. At the time of driving, each driving vibration piece 4 is flexibly vibrated around the root to the support portion 5. In this state, the vibrator 1 is rotated around a rotation axis Z extending substantially perpendicular to the vibrator 1. Then, the support part 5 bends and vibrates around the root to the fixed part 2, and each detection vibration piece 3 flexes and vibrates around the root to the fixed part 2 by the reaction. Based on the electrical signal generated in each detection vibrating piece 3, the rotational angular velocity about the Z axis is calculated.

  Here, a terminal portion 6 is provided on the fixed portion 2. Each terminal portion 6 and the electrodes on the drive vibrating piece and the detection vibrating piece are electrically connected through a wiring (not shown).

  The end portions 9c and 10c of the bonding wires 9 and 10 are bonded to the terminal portion 6 on the vibrator. In this example, each bonding wire is bonded to the terminal portion 6 on the lower surface 1b of the vibrator, and the vibrator is fixed on the bonding wire. It is necessary that the vibrator 1 is not in direct contact with the mounting surface 11 a of the substrate 11. The end portions 9c and 10c of each bonding wire can be bonded to the terminal portion 6 on the upper side surface of the vibrator 1 as shown in FIG.

  As a result, the vibrator 1 is supported and mounted on the substrate 11 by the bonding wires 9 and 10 via the frame body 7. In this state, the terminal portion of the vibrator 1 is electrically connected to the corresponding contact pads on the substrate 11 through the bonding wires 9 and 10. Further, the vibrator 1 is supported so as not to directly contact the mounting surface 11a of the substrate 11, and as a result, the vibration of the vibrator 1 is not inhibited.

  In addition, in order to adjust the space | interval between the vibrator | oscillator 1 and the mounting surface 11a, and to make the vibrator | oscillator 1 not contact the mounting surface 11a, it is vibrating by bending the edge part of each bonding wire 9 and 10. The end portions 9c and 10c on the child 1 side can be levitated from the mounting surface 11a.

  The material of the vibrator is not limited, but a piezoelectric single crystal is preferable. Crystal, lithium niobate single crystal, lithium tantalate single crystal, lithium niobate-lithium tantalate solid solution single crystal, lithium borate single crystal, langasite single crystal A piezoelectric single crystal made of, for example, is particularly preferable.

  The dimensions of the vibrator are not limited. However, if the weight and dimensions of the vibrator are large, gravity applied to the bonding wire increases, and the bonding wire may be deformed after a long period of time. For this reason, from the viewpoint of suppressing the influence on the vibration due to the deformation of the bonding wire, the width of the vibrator is preferably 10 mm or less, and more preferably 5 mm or less. From the same viewpoint, the weight of the vibrator is preferably 5 mg or less, and more preferably 1 mg or less. Further, the thickness of the vibrator is preferably 0.3 mm or less, more preferably 0.2 mm or less.

  The material of the board | substrate 11 is not specifically limited, The insulating material used for what is called a package use, for example, ceramics, glass, resin, can be used.

  The bonding wire may be supported directly on the mounting surface of the substrate, but is preferably supported on a frame on the substrate. This is because it is necessary to position a plurality of bonding wires with respect to the vibrator. At this time, positioning and aligning the plurality of bonding wires on the frame is easier than positioning the bonding wires on the mounting surface of the substrate.

  The bonding method of the bonding wire to the vibrator is not limited, but ultrasonic bonding, spot welding, conductive adhesive, and soldering are preferable.

  The bonding wire is electrically connected to the terminal portion of the vibrator. Here, in a preferred embodiment, the bonding wire is bonded to the terminal portion of the vibrator. However, the bonding wire need not be directly bonded to the terminal portion. For example, the tip of the bonding wire is bonded to a region other than the terminal portion of the vibrator, and the tip of the bonding wire and the terminal portion are electrically connected through, for example, a wiring on the vibrator or a wire separate from the vibrator. Can be connected to.

  The vibrator needs to be supported without being in direct contact with the substrate, thereby preventing the vibration of the vibrator from being hindered. In a preferred embodiment, the distance between the vibrator and the substrate is 0.1 mm or more, more preferably 0.2 mm or more.

  The method for floating the vibrator from the board mounting surface is not particularly limited. For example, in the examples of FIGS. 1 to 4, the bonding ends 9c and 10c of the bonding wires are separated from the mounting surface 11a by bending the tips of the bonding wires. However, the vibrator can be separated from the mounting surface by increasing the thickness of the contact pad on the substrate mounting surface.

  FIG. 5 is an exploded perspective view showing the support structure according to this embodiment. In FIG. 5, the same reference numerals are given to the portions shown in FIG. 1, and the description thereof is omitted. In FIG. 5, the bonding wires 19 and 20 are not bent and are substantially planar. For this reason, when the bonding wires 19 and 20 are placed on the contacts 12A and 12B (see FIG. 1) and the vibrator 1 is placed on the respective end portions 19c and 20c of the bonding wire, the distance between the vibrator 1 and the mounting surface 11a. Becomes very small and there is a risk of contact when the vibrator vibrates. For this reason, the thickness of the contact pads 17A and 17B on the substrate mounting surface 11a is increased, and the end portions 19a and 20a of the bonding wires are placed on and joined to the contact pads 17A and 17B. As a result, the vibrator 1 can be sufficiently separated from the mounting surface 11a. Reference numerals 19b and 20b denote main bodies.

  From the viewpoint of preventing the mounting surface 11a from adversely affecting the vibration of the vibrator 1, the thickness of the contact pad on the mounting surface is preferably 0.1 mm or more, and more preferably 0.2 mm or more.

  The material of the bonding wire is not particularly limited, but it needs to be a conductive material, and is preferably a material having flexibility or flexibility. From this viewpoint, copper with gold plating, nickel with gold plating, nickel, and aluminum are preferable.

  The width and thickness of the bonding wire are not particularly limited, but from the viewpoint of stably supporting the vibrator for a long period of time, the width is preferably 25 μm and the thickness is 10 μm or more, and the width is 50 μm and the thickness is 20 μm or more. More preferably it is. Further, from the viewpoint of reducing the size of the entire support structure, the width is preferably 200 μm and the thickness is 80 μm or less, and more preferably the width is 100 μm and the thickness is 40 μm or less.

  The upper surface of the vibrator can be supported by the bonding wire. In this case, for example, as shown in FIG. 9 described later, the vibrator is suspended downward from the end of the bonding wire. This form is suitable from the viewpoint of reducing the thickness of the entire support structure.

  Alternatively, for example, as shown in FIG. 4, the lower surface of the vibrator can be supported by a bonding wire. This form is suitable from the viewpoint of stably supporting the vibrator for a long period of time.

  Although the kind of board | substrate is not specifically limited, It is preferable that it is a board | substrate for a package.

  In a preferred embodiment, the vibrator includes a bending vibration piece and a fixing portion that fixes the bending vibration piece, and the fixing portion is bonded to the bonding wire. As a result, the influence of the support structure on the bending vibration of the vibrating piece can be minimized, and variations in the vibration state of each vibrator due to the influence of the support structure can be suppressed.

  In a preferred embodiment, the vibrator is a vibrator for a vibratory gyroscope for detecting a rotational angular velocity. In this case, since the angular velocity is detected by performing signal processing on the output signal from the vibrator, an error in angular velocity due to variations in the vibration state of each vibrator increases. Therefore, the effect of the present invention is particularly remarkable.

  In a preferred embodiment, the frame is made of an insulating material. In this case, each bonding wire can be directly fixed to the frame as in the example of FIGS. Although the material of such a frame is not particularly limited, resin, insulating ceramics, and glass are preferable, and specifically, polyimide, quartz glass, and alumina ceramic are preferable. Moreover, the bonding method of the bonding wire to the frame includes, for example, adhesion, fitting, crimping, and caulking.

  Further, the frame body can be formed of a conductive material. Examples of this material include metals, conductive plastics, and metal plating resins. In particular, when the frame body is made of metal, the shape stability of the frame body is further increased, thereby further increasing the accuracy during alignment of the bonding wires. Examples of the metal include stainless steel, copper, nickel, aluminum, and brass.

  However, when the frame is formed of a conductive material, it is necessary to provide an insulator between the frame and each bonding wire to insulate the bonding wire from the frame. As such an insulator, polyimide resin, epoxy resin, and silicon resin are preferable. The form of the insulator is not particularly limited, but is preferably a film or sheet.

  6 to 10 relate to an embodiment in which the frame is formed of a conductive material. FIG. 6 is an exploded perspective view of the support structure of the present invention, FIG. 7 is a plan view showing the substrate 11, the frame body 21, and the insulators 22A, 22B, and 22C used in this embodiment, and FIG. FIG. 9 is a plan view showing the bonding wires 9 and 10 fixed on the wire 21 of FIG. 7, and FIG. 9 is a plan view showing the support structure of this embodiment.

  As shown in FIG. 7, contact pads 12A and 12B are provided on the mounting surface 11a of the substrate 11 of this example. A frame body 21 is installed on the mounting surface 11a. The frame body 21 in this example is made of a conductive material. The frame body 21 includes an outer frame 21a and an auxiliary support portion 21b that protrudes inward from the outer frame 21a. A gap 8 is formed inside the frame body 21, and the mounting surface 11 a of the substrate 11 is exposed from the gap 8. Insulators 22 </ b> A, 22 </ b> B, and 22 </ b> C are fixed to predetermined portions of the outer frame 21.

  As shown in FIG. 8, the end portions 9a, 10a of the bonding wires 9, 10 are joined and fixed on the outer frame 21a via insulators 22A, 22B. The end portions 9a and 10a are electrically connected to the corresponding contact pads 12A and 12B, respectively. Elongated main bodies 9b and 10b extend from end portions 9a and 10a of the bonding wires 9 and 10, respectively. The main body 9a is supported on the auxiliary support portion 21b via the insulator 22C.

  Next, as shown in FIG. 9, the end portions 9 c and 10 c of the bonding wires 9 and 10 are bonded to the terminal portion 6 on the vibrator, and the vibrator 1 is mounted. In this example, each bonding wire is joined to the terminal portion 6 on the upper side surface 1a of the vibrator, and the vibrator is suspended below the bonding wire. In this state, the terminal portion of the vibrator 1 is electrically connected to the corresponding contact pads on the substrate 11 through the bonding wires 9 and 10.

  In addition, in order to adjust the space | interval between the vibrator | oscillator 1 and the mounting surface 11a, and to keep the vibrator | oscillator 1 from contacting the mounting surface 11a, by bending the edge part of each bonding wire 9 and 10, vibrator | oscillator The end portions 9c and 10c on the 1 side are levitated from the mounting surface 11a.

  FIG. 10 is an exploded perspective view showing a support structure according to still another embodiment. In FIG. 10, the same reference numerals are given to the portions shown in FIG. In FIG. 10, the bonding wires 19 and 20 are not bent and are substantially planar. For this reason, the thickness of the contact pads 17A and 17B on the substrate mounting surface 11a is increased, and the end portions 19a and 20a of the bonding wires are placed on and joined to the contact pads 17A and 17B. As a result, the vibrator 1 can be sufficiently separated from the mounting surface 11a.

  In a preferred embodiment, the conductive material constituting the frame is grounded. As a result, it has been found that noise due to the contribution of capacitive coupling between the bonding wires can be further reduced.

  FIG. 11 is a plan view showing a support device according to this embodiment. Since the support device of this example is similar to the support device shown in FIG. 9, the same reference numerals are given to the components shown in FIG. 9, and description thereof will be omitted. In the support device of FIG. 11, the frame body 21 is fixed and electrically connected to the mounting surface 11 a of the substrate by the conductive joint portion 25. The frame 21 can also be grounded by grounding the mounting surface 11a of the substrate. When the frame body 21 is grounded, noise due to the contribution of electrostatic coupling between the adjacent bonding wires 9 and 10 can be reduced.

  The method for grounding the conductive material is not limited, and examples thereof include conductive paste baking, soldering, conductive adhesive, and spot welding. In addition, the material of the conductive joint 25 that joins the conductive material and the substrate mounting surface may be a noble metal such as gold or silver.

It is preferable that a plurality of grounding portions of the conductive bonding material 24 exist. In this case, it is preferable that the positions of the plurality of conductive bonding materials 25 are substantially line symmetric with respect to the X axis passing through the center of gravity GO of the vibrator 1.
In this example, clearances 24 are formed so as to surround the end portions 9a and 10a of the bonding wires 9 and 10 and the insulators 22A and 22B. In the clearance 24, there is no ground electrode on the board mounting surface 11a.

  In a preferred embodiment, a cushion layer is provided between the substrate and the vibrator. FIG. 12 is an exploded perspective view showing the support device according to this embodiment. Since each component shown in FIG. 12 is shown in FIG. 1, description of the same component is abbreviate | omitted.

  In this example, the cushion material 26 is provided on the mounting surface 11 a of the substrate 11. The position of the cushion material 26 is directly below the vibrator 1. The cushion material 26 is provided with a clearance so as not to contact the vibrator 1 at the time of installation.

  This advantage will be described. When an impact is applied to the support structure from the outside, the bonding wires 9 and 10 are deformed, and the vibrator falls to the mounting surface 11a side. At this time, if the vibrator 1 directly collides with the mounting surface 11a, the vibrator may be damaged. Even when the vibrator is not damaged, the deformation of the bonding wire may exceed the elastic limit and may be plastically deformed. When the bonding wire is plastically deformed, the support state of the vibrator is changed. Therefore, there is a possibility that the rotation angular velocity around the unnecessary rotation axis is measured to generate noise or increase in temperature drift.

  On the other hand, when the vibrator drops toward the mounting surface 11a, it is possible to alleviate the impact and prevent excessive deformation of the bonding wire by holding the vibrator with the cushion material 26.

The cushion material 26 is more preferably made of a conductive material, and it is preferable to install the cushion material 26 on the mounting surface 11a from the viewpoint of suppressing electrical influence on the electrodes on the vibrator.
The material of the cushion material 26 may be, for example, a resin such as silicone resin or urethane resin, rubber, or metal spring.

  In a preferred embodiment, a grounded guard electrode is provided on an insulating material or an insulator. In a preferred embodiment, the bonding wire includes a driving-side signal electrode bonding wire to be connected to the driving-side signal electrode, a driving-side ground electrode bonding wire to be connected to the driving-side ground electrode, and a detection-side signal. A detection-side signal electrode bonding wire to be connected to the electrode, and a detection-side ground electrode bonding wire to be connected to the detection-side ground electrode.

  13 and 14 relate to this embodiment. 13 and 14 is similar to the support device shown in FIG. However, in FIG. 13, the guard electrodes 50A and 50B installed are formed on the surface of the frame 7 made of an insulating material. In this example, the bonding wires include a driving-side signal electrode bonding wire 9A, a detection-side signal electrode bonding wire 9B, a driving-side installation electrode bonding wire 10A, and a detection-side ground electrode bonding wire 10B. The drive-side ground electrode bonding wire 10A and the detection-side ground electrode bonding wire 10B are connected to the guard electrodes 50A and 50B and grounded.

  In FIG. 14, the bonding wires include a driving side signal electrode bonding wire 9A, a detection side signal electrode bonding wire 9B, a driving side installation electrode bonding wire 10A, and a detection side ground electrode bonding wire 10B. The surrounding portions 7c are formed in the frame body 7A so as to surround the end portions 9a of the signal electrode bonding wires 9A and 9B. Installed guard electrodes 50A and 50B are formed on the surface of the frame 7 made of an insulating material, and the guard electrode 50C is formed on the surrounding portion 7c. The driving-side ground electrode bonding wire 10A and the detection-side ground electrode bonding wire 10B are connected to the guard electrodes 50A and 50B and are grounded. Further, the end portions 9a of the signal electrode bonding wires 9A and 9B are surrounded by the guard electrodes 50A, 50B and 50C.

  In a preferred embodiment, a plurality of detection-side signal electrode bonding wires are included, and a plurality of lines are connected to a straight line connecting a connection portion of the drive-side signal electrode bonding wire and a connection portion of the drive-side ground electrode bonding wire. The detection-side signal electrode bonding wires are arranged at substantially symmetrical positions. In a more preferred embodiment, the plurality of detection-side ground electrode bonding wires are substantially line-symmetric with respect to a straight line connecting the connection portion of the drive-side signal electrode bonding wire and the connection portion of the drive-side ground electrode bonding wire. It is arranged at the position.

  15 to 19 relate to this embodiment. FIG. 15 shows a frame 40 made of an insulating material. The frame body 40 is provided with a central hole 42 intended to arrange the vibrator and four through holes 41 surrounding the central hole 42. 43 is a bridge part. The frame 40 in this example is made of a conductive material.

  FIG. 16 shows a state where the insulator 44 is placed on the frame body 40. FIG. 17 shows a state where the driving-side signal electrode bonding wire 45 and the driving-side ground electrode bonding wire 46 are further placed on the insulator 44. FIG. 18 shows a state where detection-side signal electrode bonding wires 47A and 47B are further placed. FIG. 19 shows a state where the detection-side ground electrode bonding wires 48A and 48B are further placed.

  For example, as shown in FIG. 17, the driving-side signal electrode bonding wire 45 includes a wiring portion 45a, a protruding portion 45b to the central hole 42, and a connecting portion 45c to the electrode pad of the vibrator. The bonding wire 45 is connected to the signal electrode on the driving side of the vibrator. The drive-side ground electrode bonding wire 46 includes a wiring portion 46a, a protrusion 46b to the central hole 42, and a connection portion 46c to the electrode pad of the vibrator. The bonding wire 46 is connected to the ground electrode on the drive side of the vibrator. In this example, the connecting portion 45c of the bonding wire 45 and the connecting portion 46c of the bonding wire 46 are opposed to each other. M is a straight line connecting the connecting portions 45c and 46c.

  As shown in FIG. 18, the detection-side signal electrode bonding wires 47A and 47B each include a wiring portion 47a, a protruding portion 47b to the central hole 42, and a connecting portion 47c to the electrode pad of the vibrator. As shown in FIG. 19, the detection-side ground electrode bonding wires 48A and 48B each include a wiring portion 48a, a protruding portion 48b to the central hole 42, a connection portion 48c to the electrode pad of the vibrator, and a guard electrode portion 48d. ing. The bonding wires 48A and 48B are grounded to the board mounting surface.

  In this example, the detection-side signal electrode bonding wires 47A and 47B are substantially line symmetrical with respect to a straight line M connecting the drive-side signal electrode bonding wire connection portion 45c and the drive-side ground electrode bonding wire connection portion 46c. It is arranged at the position. Further, a plurality of detection-side ground electrode bonding wires 48A and 48B are arranged at substantially line symmetrical positions with respect to the straight line M.

  This advantage will be described. The present inventor is considering incorporating the vibratory gyroscope into a small electronic device such as a mobile phone. However, for this purpose, the size of the vibrator needs to be remarkably reduced, and the size of the vibrator is, for example, about several mm. When this size is reached, electrostatic coupling, which was not a problem with conventional vibrators, occurs and causes noise. The spacing between the pads on the vibrator can only be about 50 μm, for example. If it becomes the dimension of this level, the contribution of the electrostatic coupling between a drive side signal pad and a detection side pad will become large. As a result, if the difference between the detection values from the two detection vibration systems is taken while the vibrator is stationary, the difference is not zero due to the contribution of electrostatic coupling, and noise is generated. Further, when the environmental temperature changes, it causes a zero point temperature drift.

  On the other hand, the detection-side signal electrode bonding wires 47A and 47B are approximately connected to the straight line M connecting the drive-side signal electrode bonding wire connection portion 45c and the drive-side ground electrode bonding wire connection portion 46c. Arranging at line-symmetrical positions can cancel out noise having the same phase and amplitude, and is effective in reducing noise by suppressing the influence of capacitive coupling. Further, it is also effective to arrange a plurality of detection-side ground electrode bonding wires 48A and 48B at substantially line symmetrical positions with respect to the straight line M.

  In a preferred embodiment, the plurality of detection-side signal electrode bonding wires 47 </ b> A and 47 </ b> B have a substantially line-symmetric shape with respect to the straight line M. That is, 47A and 47B have a substantially congruent shape. However, 47A and 47B need not be congruent.

(Experiment 1)
A support structure for the vibrating gyroscope shown in FIG. 1 was produced. Specifically, a chromium film having a thickness of 100 angstroms and a gold film having a thickness of 1500 angstroms were formed at predetermined positions on a quartz Z-plate wafer having a thickness of 0.1 mm by sputtering. Resist was coated on both sides of the wafer.

  This wafer is immersed in an aqueous solution of iodine and potassium iodide, and the excess gold film is removed by etching. Further, the wafer is immersed in an aqueous solution of cerium ammonium nitrate and perchloric acid, and the excess chromium film is etched. Removed. The wafer was immersed in ammonium bifluoride at a temperature of 80 ° C. for 20 hours, and the wafer was etched to form the outer shape of the vibrator 1. Using a metal mask, a gold film having a thickness of 2000 angstroms was formed as an electrode film on a chromium film having a thickness of 100 angstroms. The dimensions of the vibrator 1 were 3.8 mm in length, 4.5 mm in width, 0.1 mm in thickness, and the weight was about 0.8 mg.

  The vibrator 1 was mounted on a package according to the process described with reference to FIGS. However, the substrate 11 was formed of alumina ceramics, the contact pads 12A and 12B were formed of gold, and the frame body 7 was formed of polyimide resin. The frame 7 enables the bonding wires and the contact pads 12A and 12B to be aligned in the package. The bonding wire was manufactured by plating a copper film wire with gold. The thickness of the copper film wire was about 20 μm, the width was about 100 μm, and the thickness of the gold plating was about 1 μm. The bonding wire was bonded to the frame body by bonding, and bonded to the vibrator 1 by ultrasonic bonding.

(Experiment 2)
In the same manner as in Experiment 1, the support structure shown in FIGS. However, the substrate 11 was made of alumina ceramic, the contact pads were made of gold, the frame 40 was made of SUS, and the insulator 44 was made of polyimide resin. Each bonding wire was manufactured by plating a copper film wire with gold. The thickness of the copper film wire was about 20 μm, the width was about 100 μm, and the thickness of the gold plating was about 1 μm. Each bonding wire was bonded to the insulator 44 and bonded to the vibrator 1 by ultrasonic bonding.

  As described above, according to the present invention, a support device for supporting a vibrator having a terminal portion for electrical connection, the vibrator can be downsized, and each support It is possible to provide a novel support device that can suppress fluctuations in the vibration characteristics of the vibrator for each device.

It is a disassembled perspective view of the support structure of this invention. It is a top view which shows the board | substrate 11 used in the Example of FIG. 2 is a plan view showing a frame body 7 and bonding wires 9 and 10 fixed on a substrate 11. FIG. It is a top view which shows the support structure of the Example of FIG. It is a disassembled perspective view which shows the support structure which concerns on other embodiment. It is a disassembled perspective view of the support structure which concerns on other embodiment of this invention. It is a top view which shows the board | substrate 11, the frame 21, and insulator 22A, 22B, 22C used in the Example of FIG. It is a top view which shows bonding wire 12A, 12B fixed on the frame 21 of FIG. It is a top view which shows the support structure of the Example of FIG. It is a disassembled perspective view which shows the support structure which concerns on other embodiment of this invention. 3 is a plan view showing a support device in which a frame body 21 is grounded with respect to a substrate 11. 2 is an exploded perspective view showing a support device in which a cushion material 26 is provided on a substrate 11. FIG. 3 is a plan view showing a support device in which guard electrodes 50A and 50B are provided on a frame 11. FIG. 3 is a plan view showing a support device in which guard electrodes 50A to 50C are provided on a frame body 11. FIG. It is a top view which shows the frame 40 which consists of an electroconductive material. 3 is a plan view showing a frame body 40 and an insulator 44. FIG. 3 is a plan view showing a frame body 40, an insulator 44, a driving-side signal electrode bonding wire 45, and a driving-side ground electrode bonding wire 46. FIG. 4 is a plan view showing a frame body 40, an insulator 44, a driving-side signal electrode bonding wire 45, a driving-side ground electrode bonding wire 46, and detection-side signal electrode bonding wires 47A and 47B. FIG. The top view of a support apparatus is shown.

  DESCRIPTION OF SYMBOLS 1 Vibrator 2 Fixed part 3 Detection vibration piece (flexural vibration piece) 4 Drive vibration piece (flexural vibration piece) 5 Support part (flexural vibration piece) 6 Terminal part 7 Frame body 7a, 21a Outer frame 7b, 21b Auxiliary support part 9, 10 Bonding wire (with end bent) 9a, 10a Bonding wire frame end part 9c, 10c Bonding wire vibrator end part 11 Substrate 11a Substrate mounting surface 12A, 12B Contact Pads 17A, 17B Thick contact pads 19, 20 Planar bonding wires (no end bending) 21 Frame made of conductive material

Claims (17)

A support device for supporting a vibrator having a terminal portion for electrical connection,
A substrate, and a bonding wire supported on the substrate and to be bonded to the vibrator; supporting the vibrator without contacting the substrate by the bonding wire; and the bonding An apparatus for supporting a vibrator, wherein a wire is configured to be electrically connected to the terminal portion.   The support device according to claim 1, wherein the substrate includes a contact point that is electrically connected to the bonding wire.   The support device according to claim 1, further comprising a frame body for fixing and supporting the bonding wire.   The support device according to claim 3, wherein the frame is made of an insulating material.   The support device according to claim 4, wherein a grounded guard electrode is provided on the insulating material.   The support device according to claim 3, wherein the frame is made of a conductive material, and includes an insulator that insulates the frame from the bonding wire.   The support device according to claim 6, wherein the conductive material is grounded.   The support device according to claim 6, wherein a grounded guard electrode is provided on the insulator.   The support device according to claim 1, wherein at least a lower surface of the vibrator is supported by the bonding wire.   The support device according to claim 1, wherein the substrate is a package substrate.   The support device according to any one of claims 1 to 10, wherein a cushion layer is provided between the substrate and the vibrator.   The vibrator includes a bending vibration piece and a fixing portion that fixes the bending vibration piece, and the bonding wire is configured to be able to be bonded to the fixing portion. The support device according to any one of claims 1 to 11.   The support device according to any one of claims 1 to 12, wherein the vibrator is a vibrator for a vibratory gyroscope for detecting a rotational angular velocity.   The bonding wire is a driving-side signal electrode bonding wire to be connected to the driving-side signal electrode, a driving-side ground electrode bonding wire to be connected to the driving-side ground electrode, and a detection side to be connected to the detection-side signal electrode The support device according to any one of claims 1 to 13, further comprising a bonding wire for a signal electrode and a bonding wire for a detection-side ground electrode to be connected to the detection-side ground electrode.   A plurality of the detection-side signal electrode bonding wires, and the detection-side signal electrode for a straight line connecting the connection portion of the drive-side signal electrode bonding wire and the connection portion of the drive-side ground electrode bonding wire. 15. The support device according to claim 14, wherein the bonding wires are arranged at substantially line symmetrical positions.   A plurality of the detection-side ground electrode bonding wires, and the detection-side ground electrode for a straight line connecting a connection portion of the drive-side signal electrode bonding wire and a connection portion of the drive-side ground electrode bonding wire The supporting device according to claim 14 or 15, wherein the bonding wires are arranged at substantially line symmetrical positions.   A support structure for a vibrator, comprising the support device according to any one of claims 1 to 16 and a vibrator supported by the support device.

Images