JP2000241165A - Manufacturing method of vibrating gyroscope type angular velocity sensor - Google Patents

Abstract

(57) Abstract: Provided is a method of manufacturing a vibrating gyroscope-type angular velocity sensor that can efficiently perform a polarization operation of a piezoelectric element without applying a load to a vibrating body. SOLUTION: A piezoelectric plate 10 is formed in a rectangular plate shape, and is subjected to a plating process after a lapping process in advance. In this plating step, only one surface of the piezoelectric plate 10 is plated with nickel, and the other surface is plated with gold from above nickel plating. Next, the peripheral end of the piezoelectric plate 10 is cut,
Insulate between plating surfaces. Then, a polarization process is performed on the piezoelectric plate 10 by applying a high voltage and a high temperature in a polarization process. Thereafter, in a dividing step, the piezoelectric plate 10 is divided into strips, and a large number of piezoelectric elements 30 are obtained. Then, the piezoelectric element 30 is bonded to the side surface of the vibrating body 40 with an adhesive with the gold-plated surface of the piezoelectric element 30 facing outward, and wiring is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vibrating gyroscope-type angular velocity sensor having a vibrating body and a piezoelectric element, and more particularly to a polarization processing of a piezoelectric element.

[0002]

2. Description of the Related Art Hitherto, as a vibrating gyroscope-type angular velocity sensor, a sensor using a piezoelectric element has been known (for example, Japanese Patent Application Laid-Open No. 7-83669 and Japanese Patent Application Laid-Open No. 2-22381).
No. 7, JP-A-3-214016). Angular velocity sensors using this piezoelectric element are used in devices such as camera shake correction of video cameras and car navigation. In response to demands for downsizing and cost reduction of these devices, there is a demand for downsizing, high performance, and low price of the angular velocity sensor itself.

For example, as an angular velocity sensor using a piezoelectric element, a sensor having a structure in which a piezoelectric element made of a piezoelectric material is adhered to a side surface of a prism-shaped vibrator made of a constant elastic material called an elinvar is used. In this piezoelectric element, it is formed as a substantially rectangular flat plate, and in order to exhibit the performance as a piezoelectric element, it is necessary to perform a so-called polarization process of applying a high voltage of 600 V and a high temperature of 120 ° C. is there.

[0004]

By the way, in the conventional method of manufacturing an angular velocity sensor, the above-described polarization treatment of the piezoelectric element is performed after the piezoelectric element is bonded to the elinvar. However, such a method requires equipment for polarization in direct proportion to the production quantity. In addition, the polarization operation itself is an operation for each product unit, which also requires man-hours in proportion to the production amount. In addition, the polarization operation after bonding to the elinvar causes high voltage and high temperature to be applied to the vibrating body, which causes distortion in the elinvar as the vibrating body, causing variations in characteristics and reliability problems. It is a factor to make it.

An object of the present invention is to provide a method of manufacturing a vibrating gyroscope-type angular velocity sensor that can efficiently perform a polarization operation of a piezoelectric element without applying a load to a vibrating body.

[0006]

In order to achieve the above object, the present invention provides a method for manufacturing a vibrating gyroscope-type angular velocity sensor having a columnar vibrator and a plurality of piezoelectric elements adhered to side surfaces of the vibrator. A dividing step of dividing a piezoelectric plate to form a large number of the piezoelectric elements; an adhering step of adhering the divided piezoelectric elements to the vibrating body; and a polarizing step of applying a high voltage and a high temperature to the piezoelectric elements. And the polarization step is performed before the division step.

In the method of manufacturing a vibrating gyroscope-type angular velocity sensor according to the present invention, a high voltage and a high temperature are applied to a piezoelectric plate before division after a lapping step, a plating step, and the like to perform a polarization step. Next, in a dividing step, the piezoelectric plate is divided to form a piezoelectric element having a predetermined shape, and the divided piezoelectric element is bonded to the vibrating body in a bonding step. Therefore, compared to the conventional method of individually performing the polarization step on the piezoelectric elements bonded to the vibrating body, the polarization operation of a large number of piezoelectric elements can be performed collectively and efficiently, and the polarization operation can be performed efficiently. Therefore, no load is applied to the vibrating body.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for manufacturing a vibrating gyroscope type angular velocity sensor according to the present invention will be described. 1 to 8 are process diagrams showing a specific example of a method for manufacturing a vibrating gyroscope-type angular velocity sensor according to the present invention.

First, FIG. 1 is a perspective view showing a piezoelectric plate 10 for forming a large number of piezoelectric elements by a dividing step in this embodiment. The piezoelectric plate 10 is made of a piezoelectric material such as a specific ceramic, for example, and has a predetermined thickness (for example, 0.1 mm).
2 mm). This piezoelectric plate 10 has both surfaces previously treated by a lapping process.

Next, FIG. 2 shows a plating step.
First, as shown in FIG. 2A, nickel plating (first plating) is applied to the entire piezoelectric plate 10 (both front and back surfaces and the entire peripheral end surface).
12 is applied. Next, as shown in FIG.
Gold plating on nickel plating only on one side of
14) is applied. Next, as shown in FIG. 3, the peripheral end 10 </ b> A of the piezoelectric plate 10 is cut so that the positive and negative pole surfaces of the piezoelectric plate 10 are insulated.

FIG. 4 shows a specific example of an apparatus for performing this cutting step. FIG. 4 (A) is a plan view and FIG. 4 (B) is a side view. As shown in the drawing, in this cutting operation, a plurality of piezoelectric plates 10 are positioned and fixed in a state of being superimposed on the set surface 20A of one cutting jig 20, so that a plurality of sheets can be processed at a time. And the escape groove 20B of the cutting jig 20
Then, by sending a cutting tool (not shown), the four ends 10B of the piezoelectric plate 10 are cut. As described above, it is possible to obtain the piezoelectric plate 10 in which different types of plating are applied to the positive electrode surface and the negative electrode surface. Here, by applying the gold plating 14 to only one side, the positive and negative poles of each of the piezoelectric elements divided in the dividing step described later can be easily confirmed visually. Also, in the bonding step described later, the gold plating surface can be improved by improving the corrosion resistance and the soldering property by improving the reliability by improving the gold plating surface by arranging the surface on the gold plating 14 side outside and bonding to the vibrator. Can be secured.

Next, the piezoelectric plate 10 is washed and dried, and the process proceeds to a polarization step. In this polarization step, high-voltage energy of, for example, 600 V and high-temperature energy of 120 ° C. are applied to each piezoelectric plate 10. FIG. 5 shows a specific example of an apparatus for performing this polarization step. FIG. 5 (A) is a front view, and FIG. 5 (B) is a side view. As shown in the figure, a plurality of piezoelectric plates 10 are positioned and fixed in parallel on a set surface 22A of a jig 22 for polarization work. Then, a probe unit 24 having a large number of probe pins 24A is arranged on the upper surface thereof, and the probe pins 24A are set on each piezoelectric plate 10. In addition,
An intermediate insulating plate 26 is disposed between the jig 22 and the probe unit 24.

Here, a high voltage is applied with the jig 22 side being a minus pole and the probe unit 24 side being a plus pole. Each of the piezoelectric plates 10 is arranged such that the surface on which the gold plating 14 is applied is on the positive electrode side. A plurality of (for example, nine) probe pins 24A are provided for one piezoelectric plate 10, and are arranged so that a uniform voltage is applied to the entire surface of the piezoelectric plate 10. In this polarization processing, for example, 60
Energy of a high voltage of 0 V and a high temperature of 120 ° C. is applied to the piezoelectric plate 10.

Next, a dividing step of dividing the polarized piezoelectric plate 10 into a substantially strip shape is performed. 6A and 6B show a specific example of an apparatus for performing the dividing step. FIG. 6A is a plan view, and FIG. 6B is a front view. As shown in the drawing, in this dividing operation, a plurality of piezoelectric plates 10 are cut into one cutting jig 28.
The positioning and fixing can be performed in a state of being superimposed on the set surface 28A, and a plurality of sheets can be processed collectively. Then, by sending a cutting tool (not shown) along the escape groove 28B of the cutting jig 28, the piezoelectric plate 10 is cut into a substantially strip shape.
A large number of piezoelectric elements 30 as shown in FIG.

FIG. 8 is a view showing a state in which the piezoelectric element 30 formed as described above is bonded to the vibrating body 40 to form an angular velocity sensor. FIG. 8A is an overall perspective view, and FIG. 8B is a cross-sectional view showing the wiring of each piezoelectric element 30, FIG.
(C) is a sectional view showing a vibration direction of the vibrating body. FIG.
As shown in (A), the vibrating body 40 is formed in the shape of a quadrangular prism, and includes, for example, an elinvar, an iron-nickel alloy, quartz,
It is generally made of a material that generates mechanical vibration, such as glass, quartz, and ceramics. The piezoelectric elements 30A, 30B, 30C,
30D is bonded with a suitable adhesive with the gold-plated surface facing out as described above. During this bonding work,
The above-mentioned nickel-plated surface (silver) and gold-plated surface (gold) make it easy to visually identify the front and back of the piezoelectric element,
Definitely easy bonding can be achieved.

As shown in FIG. 8B, of the piezoelectric elements 30A, 30B, 30C, and 30D, a pair of parallel piezoelectric elements 30A and 30C serve as driving piezoelectric elements and supply a drive signal supply circuit (see FIG. 8B). The other pair of parallel piezoelectric elements 30B and 30D is connected to a detection circuit (not shown) as a detection piezoelectric element. Then, as shown in FIG. 8C, the driving piezoelectric elements 30A,
By supplying a driving signal to 30C, the vibrating body 40 vibrates in the Y direction by the driving force. As a result, the vibrating body 40 generates a vibration due to Coriolis force in the X direction according to the angular velocity, and this vibration is detected by the detecting piezoelectric element 30B,
Detect via 30D.

In the above manufacturing method, the polarization ability is 1
More than 00 times, the jig for element polarization, DC power supply, and polarization man-hour can be greatly reduced as compared with the conventional method, and at the same time, high voltage and high temperature are applied to the vibrating body and the adhesive. Are not added at the same time, and a low-cost and highly reliable angular velocity sensor can be manufactured. Further, by applying uniform polarization to the plate-shaped piezoelectric plate at the same time, the variation in the Q characteristic of each piezoelectric element can be greatly reduced to one tenth or less as compared with the conventional piezoelectric element, and the performance is improved. be able to. The shape of the vibrating body 40, the structure of the angular velocity sensor, and the like are not limited to the above examples, and can be applied to various forms. Further, specific materials such as a piezoelectric plate, plating, and an adhesive can be appropriately modified.

[0018]

As described above, in the method of manufacturing the vibrating gyroscope type angular velocity sensor according to the present invention, the piezoelectric plate before the division is polarized by applying a high voltage and a high temperature to the piezoelectric plate and then dividing the piezoelectric plate. Thus, a piezoelectric element having a predetermined shape was formed, and the divided piezoelectric element was bonded to the vibrator. Therefore, compared to the conventional method of individually performing the polarization step on the piezoelectric elements bonded to the vibrating body, the polarization operation of a large number of piezoelectric elements can be performed collectively and efficiently, and the polarization operation can be performed efficiently. Therefore, no load is applied to the vibrating body.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a plate-like piezoelectric plate used in a method of manufacturing a vibration gyro-type angular velocity sensor according to the present invention.

FIG. 2 is a perspective view showing a state in which a plating step is performed on the plate-shaped piezoelectric plate shown in FIG.

FIG. 3 is a perspective view showing a state in which plating removal (cutting step) has been performed on the plate-shaped piezoelectric plate shown in FIG. 2;

4A and 4B are a plan view and a side view showing an apparatus configuration for performing plating removal (cutting step) on the plate-shaped piezoelectric plate shown in FIG.

5A and 5B are a front view and a side view showing an apparatus configuration for performing a polarization step on the plate-shaped piezoelectric plate shown in FIG.

6A and 6B are a plan view and a front view showing an apparatus configuration for performing a dividing step on the plate-shaped piezoelectric plate shown in FIG.

FIG. 7 is a perspective view showing a piezoelectric element divided by the dividing step shown in FIG. 6;

8A and 8B are an overall perspective view and a cross-sectional view showing a state in which the piezoelectric element shown in FIG. 7 is bonded to a vibrator to form an angular velocity sensor.

[Explanation of symbols]

10: piezoelectric plate, 10A: peripheral end, 12: nickel plating, 14: gold plating, 30, 30A, 30B, 3
0C, 30D: piezoelectric element, 40: vibrator.

Claims (6)

[Claims] 1. A method of manufacturing a vibrating gyroscope-type angular velocity sensor having a columnar vibrating body and a plurality of piezoelectric elements adhered to side surfaces of the vibrating body, wherein a plurality of piezoelectric elements are formed by dividing a piezoelectric plate. A dividing step, a bonding step of bonding the divided piezoelectric element to the vibrating body, and a polarizing step of applying a high voltage and a high temperature to the piezoelectric element. A method for manufacturing a vibrating gyroscope-type angular velocity sensor, which is performed before. 2. The vibrating gyroscope-type angular velocity sensor according to claim 1, further comprising a plating step of plating different types of plating on the positive electrode surface and the negative electrode surface of the piezoelectric plate before the polarization step. Manufacturing method. 3. The vibration according to claim 2, wherein in the plating step, a first plating having a predetermined thickness is applied to both surfaces of the piezoelectric plate, and then a second plating is applied to only one surface. A method for manufacturing a gyro-type angular velocity sensor. 4. The method for manufacturing a vibrating gyroscope-type angular velocity sensor according to claim 3, wherein the piezoelectric element has a surface opposite to the surface on which the second plating is applied, bonded to the vibrating body. 5. After the first plating is applied to the whole of the piezoelectric plate, a second plating is applied to only one surface thereof, and a peripheral end of the piezoelectric plate is cut. 4. The method for manufacturing a vibrating gyroscope-type angular velocity sensor according to claim 3, wherein the polarization step is performed while the surfaces are insulated. 6. The method according to claim 3, wherein the first plating is nickel plating, and the second plating is gold plating.