JP2004085233A - Columnar vibrator for piezoelectric vibration gyro and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a compact, low-cost columnar vibrator for piezoelectric vibration gyros that easily achieves the formation of an electrode and the assembly of a support member and does not lose mechanical strength by miniaturization. <P>SOLUTION: The columnar vibrator for piezoelectric vibration gyros comprises one drive electrode 3 for performing bending vibration in a first direction; and two detection electrodes 2, 4 for detecting the bending vibration in a second direction which is perpendicular to the first direction are provided on one side surface in a columnar body 1 made of a piezoelectric body, while being supported by a support member near the node position of the bending vibration. In the columnar vibrator for piezoelectric vibration gyro, the drive electrode and the detection electrode are formed in one piece, with the support member being a metallic body. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gyroscope used mainly for a navigation system and attitude control of an automobile, a camera shake prevention device for a camera-type VTR, and particularly to a columnar vibrator for a piezoelectric vibrating gyroscope and a method of manufacturing the same.
[0002]
[Prior art]
A piezoelectric vibrating gyroscope is an angular velocity sensor utilizing a mechanical phenomenon in which when an object having a velocity is given an angular velocity, a Coriolis force is generated in the object itself in a direction perpendicular to the velocity direction.
[0003]
By applying an electrical signal, mechanical vibration (drive vibration) can be excited, and the magnitude of mechanical vibration (detection vibration) in a direction perpendicular to the drive vibration can be electrically detected. In a system with the above, when an angular velocity about an axis parallel to a line intersecting the driving vibration surface and the detection vibration surface is given in a state where the driving vibration is excited in advance, the detection vibration is caused by the action of the aforementioned Coriolis force. Occurs and is detected as an output voltage. Since the detected output voltage is proportional to the magnitude of the drive vibration and the angular velocity, the magnitude of the angular velocity can be obtained from the magnitude of the output voltage when the magnitude of the drive vibration is constant.
[0004]
For the vibrating gyroscope, vibrators of various shapes have been proposed, but the columnar vibrating piece vibrator made of a piezoelectric material is often used for a small and inexpensive vibrating gyroscope due to its simple shape. . Further, among the columnar vibrators for piezoelectric vibrating gyroscopes, those in which the electrode and support structure of the columnar vibrator are devised for the purpose of further miniaturization and lower cost have been proposed.
[0005]
The present applicant has proposed a columnar vibrator for a piezoelectric vibrating gyroscope in Japanese Patent No. 3122925. The structure is shown in FIG. As shown in FIG. 5, a driving electrode 23 and detection electrodes 22 and 24 are provided on one side surface of a columnar body 21 made of a piezoelectric material, and excitation of driving vibration in the X direction in the drawing and detection of detection vibration in the Y direction can be performed. This satisfies the function as a columnar vibrator for a piezoelectric vibrating gyroscope. Since all the electrodes are provided on one side surface, the electrodes can be easily formed by screen printing, photolithography, or the like, as compared with the case where the electrodes are provided on a plurality of side surfaces. Therefore, a small and inexpensive columnar vibrator for a piezoelectric vibrating gyroscope can be obtained. However, regarding the support of the columnar vibrator, a structure that is particularly small and can be manufactured at low cost cannot be proposed, and a problem remains in the future.
[0006]
With respect to the support structure of the columnar vibrator, a structure shown in, for example, Japanese Patent Application Laid-Open No. 9-273934 of FIG. 6 has been proposed. As shown in FIG. 6, the supporting members 35, 36, 37 having conductivity and having bent portions are used to support the columnar body 31 made of a piezoelectric bimorph having the detection electrodes 32, 34 and the driving electrode 33. By doing so, the driving vibration of the columnar vibrator in the X direction in the figure and the detection vibration in the Y direction in the figure are not suppressed, that is, without adversely affecting various characteristics such as the sensitivity of the vibrating gyroscope, And mechanical connection can be performed simultaneously to improve productivity.
[0007]
[Problems to be solved by the invention]
However, the conventional columnar vibrator shown in FIG. 6 requires a step of accurately positioning the support member to connect to the drive electrode 33 and the detection electrodes 32 and 34 of the columnar vibrator, and then connecting with a solder 38 or the like. there were. The support member can be easily obtained by etching, bending, or punching, but since the shape is long and narrow, the dimensional accuracy tends to vary due to warpage or torsion, etc., and the node of the bending vibration of the columnar oscillator with high accuracy. It was not easy to position the support member at the position and connect it to the electrodes of the columnar vibrator by soldering or the like. In addition, since the columnar vibrator is designed to be suspended in a hollow space, it is necessary to sufficiently consider mechanical strength, and it is necessary to secure a certain bonding area for connection of solder or the like, which hinders miniaturization.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide a small and inexpensive columnar vibrator for a piezoelectric vibrating gyroscope in which electrode formation and assembling of a support member are easy and the mechanical strength is not impaired, and a method of manufacturing the same.
[0009]
[Means for Solving the Problems]
The present invention provides a columnar body having at least one or more flat sides made of a piezoelectric body, one driving electrode necessary for bending and vibrating in a first direction, and a column perpendicular to the first direction. A columnar vibration for a piezoelectric vibratory gyroscope provided with two detection electrodes necessary for detecting a bending vibration in a certain second direction on the one flat side surface and supported by a support member near a node position of the bending vibration. The driving electrode and the detection electrode are a columnar vibrator for a piezoelectric vibrating gyroscope, wherein the driving electrode and the detecting electrode are metal bodies formed integrally with the supporting member. Joining a metal plate having a larger area to the one flat side surface of the columnar body, and simultaneously forming the electrode and the support member by etching the metal plate, respectively; Li Cheng can be realized by the manufacturing method of a piezoelectric vibrating gyroscope for columnar vibrator.
[0010]
That is, according to the present invention, one driving electrode that causes bending vibration in a first direction and bending vibration in a second direction perpendicular to the first direction are applied to one side surface of a columnar body made of a piezoelectric body. In a columnar vibrator for a piezoelectric vibrating gyroscope comprising two detection electrodes for detecting and supported by a support member near a node position of the bending vibration, the drive electrode and the detection electrode are formed integrally with the support member, respectively. And a columnar vibrator for a piezoelectric vibrating gyroscope made of a metal body.
[0011]
Further, according to the present invention, one driving electrode for bending and vibrating in a first direction and a bending vibration in a second direction perpendicular to the first direction are provided on one side surface of a columnar body made of a piezoelectric material. In a method for manufacturing a columnar vibrator for a piezoelectric vibrating gyroscope in which two detection electrodes to be detected are formed and supported by a support member near a node position of the bending vibration, a metal having an area larger than the side surface on one side surface of the columnar body A method of manufacturing a columnar vibrator for a piezoelectric vibrating gyroscope, comprising a step of joining plates and a step of simultaneously forming the electrodes and the support members by etching the metal plate.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
A columnar vibrator for a piezoelectric vibrating gyroscope and a method for manufacturing the same according to an embodiment of the present invention will be described below.
[0013]
FIG. 1 is a perspective view of a columnar vibrator for a piezoelectric vibrating gyroscope according to an embodiment of the present invention. The columnar vibrator according to the present invention includes a linear drive electrode 3 and detection electrodes 2 and 4 made of metal on one side surface of a columnar body 1 made of a piezoelectric body and having a rectangular cross section. It is applied parallel to the longitudinal direction. Note that the detection electrodes 2 and 4 are short-circuited to the columnar body 1, and a high electric field is applied between the columnar body 1 and the drive electrode 3.
[0014]
FIG. 2 is a cross-sectional view showing the vicinity of the antinode of bending vibration in the columnar vibrator for a piezoelectric vibrating gyroscope according to the embodiment of the present invention. As shown in FIG. 2, the polarization process is performed in the direction of arrow P in the cross-sectional view near the abdomen of the columnar body 1. With this configuration, the columnar vibrator of the present invention enables excitation of driving vibration in the X direction in the drawing and detection of detection vibration in the Y direction, and satisfies the function as a columnar vibrator for a piezoelectric vibrating gyroscope.
[0015]
Further, as shown in FIG. 1, each electrode is protruded from the side surface of the columnar body 1 in the vicinity of the node of the bending vibration, and the electrode is formed so as to be extended and at the same time to have a bending portion in the middle. The extended electrodes serve to support the columnar bodies and also function as input / output wiring for each electrode. The tip of the extended electrode is connected and fixed to a terminal or the like connected to the drive detection circuit (not shown). The columnar vibrator of the present invention functions as a piezoelectric vibrating gyroscope by being connected to a circuit having a simple configuration disclosed in Japanese Patent No. 3122925.
[0016]
Next, a specific manufacturing method according to the embodiment of the present invention will be described below with reference to FIGS.
[0017]
FIG. 3 is an explanatory diagram showing an example of joining a metal plate and a piezoelectric body in a process of manufacturing a columnar vibrator for a piezoelectric vibrating gyroscope according to an embodiment of the present invention. FIG. 3A is an explanatory diagram of a state where unevenness is formed on a piezoelectric flat plate. FIG. 3B is an explanatory diagram of a state where the piezoelectric plate and the metal plate are joined, and FIG. 3C is an explanatory diagram of a state where the lower side is polished in the state of FIG. 3B. .
[0018]
As shown in FIG. 3A, slits are formed at equal intervals on one surface of the piezoelectric flat plate 11 by dicing or the like, and irregularities are formed on the piezoelectric flat plate. Next, the convex surface 11a is mirror-polished as it is or after the metallizing treatment, and the metal plate 5 is superimposed on the convex surface 11a and pressurized in a high temperature or in a vacuum, as shown in FIG. The flat plate 11 and the metal plate 5 are firmly joined.
[0019]
After the joining, the piezoelectric flat plate 11 is scraped off by polishing or the like from the bottom surface 11b side until the convex portion is completely independent, and as shown in FIG. What is arranged and joined at intervals is obtained. As a method for obtaining the one shown in FIG. 3 (c), in addition to this, a piezoelectric film is formed by a physical vapor phase growth method such as vacuum evaporation / sputtering or a liquid phase growth method such as a sol-gel method / hydrothermal synthesis method. Is a method in which fine particles of a piezoelectric material collide with a metal plate at a high speed, or the like, and a plurality of columnar bodies 1 can be precisely arranged on a metal plate 5 and directly joined.
[0020]
FIG. 4 is an explanatory view showing an example of an etching process of a metal plate in a manufacturing process of the columnar vibrator for the piezoelectric vibrating gyroscope according to the embodiment of the present invention. FIG. 4A is an enlarged view of a metal plate in which a plurality of pillars are joined, FIG. 4B is an explanatory view of a state where the entire surface is coated with a resist, and FIG. FIG. 4D is an explanatory view of a state where a metal plate is etched, and FIG. 4E is an explanatory view of a finished columnar vibrator.
[0021]
FIG. 4A is an enlarged view of one of the metal plates 5 in which a plurality of pillars are joined. In the next step, the entire surface is coated with a resist 6 as shown in FIG.
[0022]
Next, by exposing using a metal mask having a predetermined pattern and removing unnecessary portions, the resist 6 is patterned as shown in FIG. Next, the metal plate 5 is processed into the shape shown in FIG. 4D by etching the exposed portion of the metal plate 5. Next, by removing all the resists, as shown in FIG. 4E, a plurality of columnar vibrators in which the electrodes and the support portions are integrated can be obtained at the same time.
[0023]
Finally, by cutting into individual pieces, the columnar vibrator shown in FIG. 1 is obtained. At the stage before cutting into individual pieces, each electrode in the plurality of pillars is short-circuited via the support member. Sexually preferred.
[0024]
【The invention's effect】
According to the columnar vibrator for a piezoelectric vibrating gyroscope and the method of manufacturing the same according to the present invention, the dimensional accuracy of the constituent members is hardly varied, so that the electrode formation and the assembling of the support member can be easily and accurately realized. Further, a plurality of columnar vibrators can be simultaneously manufactured, including the polarization treatment, and the productivity is excellent. In addition, since solder and the like are not used for assembly, variations in mechanical strength due to assembly variations are unlikely to occur, and since the support member is joined to most of the side surfaces of the columnar body, mechanical Excellent strength. For this reason, miniaturization is possible without impairing reliability.
[Brief description of the drawings]
FIG. 1 is a perspective view of a columnar vibrator for a piezoelectric vibrating gyroscope according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the vicinity of an antinode of bending vibration in the columnar vibrator for a piezoelectric vibrating gyroscope according to the embodiment of the present invention.
FIG. 3 is an explanatory view showing an example of joining a metal plate and a piezoelectric body in a process of manufacturing a columnar vibrator for a piezoelectric vibrating gyroscope according to an embodiment of the present invention. FIG. 3A is a diagram illustrating a state in which irregularities are formed on a piezoelectric flat plate. FIG. 3B is an explanatory view of a state where the piezoelectric flat plate and the metal plate are joined, and FIG. 3C is an explanatory view of a state where the lower side is polished in the state of FIG. 3B.
FIG. 4 is an explanatory view showing an example of etching of a metal plate in a manufacturing process of the columnar vibrator for the piezoelectric vibrating gyroscope according to the embodiment of the present invention. FIG. 4A is an enlarged view of a metal plate in which a plurality of columnar bodies are joined, FIG. 4B is an explanatory view of a state where the entire surface is coated with a resist, and FIG. 4C is a state where the resist is patterned. FIG. 4D is an explanatory view of a state where a metal plate is etched, and FIG. 4E is an explanatory view of a finished columnar vibrator.
FIG. 5 is a perspective view showing a conventional columnar vibrator for a vibrating gyroscope.
FIG. 6 is a perspective view showing another conventional columnar vibrator for a vibrating gyroscope.
[Explanation of symbols]
1, 21, 31 Pillars 2, 4, 22, 24, 32, 34 Detecting electrodes 3, 23, 33 Driving electrodes 5 Metal plate 6 Resist 11 Piezoelectric flat plate 11a Convex surface 11b Bottom surface 35, 36, 37 Support member 38 Solder

Claims (2)

One drive electrode for bending vibration in a first direction and two detection electrodes for detecting bending vibration in a second direction perpendicular to the first direction, on one side surface of a columnar body made of a piezoelectric body. Wherein the drive electrode and the detection electrode are metal bodies formed integrally with the support member, respectively, in the columnar vibrator for a piezoelectric vibratory gyroscope supported by a support member near a node position of the bending vibration. A columnar vibrator for a piezoelectric vibrating gyroscope, characterized by the following. One drive electrode for bending vibration in a first direction and two detection electrodes for detecting bending vibration in a second direction perpendicular to the first direction, on one side surface of a columnar body made of a piezoelectric body. Forming, and in a method of manufacturing a columnar vibrator for a piezoelectric vibrating gyroscope supported by a support member near a node position of the bending vibration, a step of joining a metal plate having an area larger than the side surface to one side surface of the columnar body. Forming the electrode and the supporting member simultaneously by etching the metal plate.

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