JPH0682870B2 - Piezoelectric element manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a piezoelectric element having electrode patterns on both surfaces.

[Outline of Invention]

The present invention relates to a method of manufacturing a piezoelectric element having electrode patterns on both sides, wherein a single electrode and a positioning pattern are formed on a first surface, and then a second pattern is formed with the positioning pattern formed on the first surface as a reference. A method of manufacturing a piezoelectric element, in which a plurality of divided electrode patterns are formed on the surface of the first surface, polarization processing is performed, and then a conductive electrode pattern is formed on the second surface again with reference to the positioning pattern formed on the first surface. By using, the positioning of the piezoelectric element with respect to the mask jig is facilitated when the electrode pattern is formed, and the positional deviation of each electrode pattern formed on the second surface is prevented.

Further, by using the piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention in an ultrasonic motor using a flexural traveling wave component, it is possible to realize high efficiency and productivity improvement of the motor. is there.

[Conventional technology]

The electrode structure of the conventional piezoelectric element is as shown in FIG. 8 and FIG. When an electrode pattern as shown in FIG. 9 is realized, it is impossible to polarize electrically conductive electrode patterns in different directions. Therefore, after first forming a plurality of divided electrode patterns, Once the piezoelectric element was taken out of the thin film forming apparatus, subjected to polarization processing, and then repositioned on the mask jig in the thin film forming apparatus again.
Inner and outer periphery conduction patterns must be formed. At that time, conventionally, as shown in FIG. 8, the first surface opposite to the second surface on which the plural-divided electrode pattern is formed is only formed with the one-body electrode pattern concentric with the piezoelectric element. However, it has been very difficult to position the mask jig.

[Problems to be Solved by the Invention]

In the piezoelectric element manufacturing method as described above, since the piezoelectric element has a disk shape, it is easy to position the piezoelectric element once removed from the mask jig and position it again on the mask jig because there is no positioning guide. This is not a matter of course, but there is a problem such as displacement of the electrode pattern. Further, in many cases, the vacuum evaporation method which is often used as a thin film forming means has an evaporation apparatus as shown in FIG.
It is necessary to set the surface on which the electrode pattern is to be formed downward on the mask jig, and when forming a complicated electrode pattern as shown in FIG. 9, it is necessary to align from the lower side. And so on.

Further, as a positioning guide, a means such as providing a notch in a part of the piezoelectric element or marking with an ink or the like can be considered, but if the notch is provided, the piezoelectric element such as spurious may be convenient in terms of vibration characteristics, Even if ink or the like is used, there is a problem that it disappears when ultrasonic cleaning is performed after the polarization treatment.

Therefore, an object of the present invention is to solve the above problems and to provide a method of manufacturing a piezoelectric element that facilitates positioning when forming electrode patterns in different shapes on the same surface in multiple steps. To provide.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a piezoelectric element having electrode patterns on both surfaces, in which one electrode and a positioning pattern are first formed on the first surface, and then the first electrode is formed.
A plurality of divided patterns are formed on the second surface which is opposed to the positioning pattern formed on the first surface, which is then subjected to a polarization process, and is then opposed to the positioning pattern formed on the first surface again. By means of forming another electrode pattern such as an electrode pattern for conduction on the second surface, the positional deviation between the electrode patterns formed on the second surface is prevented.

[Action]

According to the above configuration, when the electrode pattern is formed on the one surface of the piezoelectric element having the electrode patterns on both sides by the vapor deposition means or the like in plural times, the shape of the piezoelectric element is changed. Without this, positioning on a mask jig or the like becomes easy, and it is possible to prevent positional deviation during electrode pattern formation.

In addition, even when the piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention is used in an ultrasonic motor, a uniform electrode pattern with no positional deviation can be obtained. It is very advantageous for improvement and high efficiency.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 are views showing an example of an electrode structure of a piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention, in which a plan view of a first surface and a plan view of a second surface are sequentially shown. 3 is a vertical sectional view. FIG. 1 shows that a one-body electrode pattern 102 is formed on the first surface of a piezoelectric element 101 having a central hole 104, and positioning electrode patterns 103 are formed at two locations on the outer peripheral portion.
It shows how to set. That is, by forming different shapes in two portions of the one-body electrode pattern, it can be used as a positioning mark for the mask jig when forming electrodes on the opposite surfaces. Generally, when adjacent divided electrode patterns as shown in FIG. 2 are to be polarized in different directions, it is not possible to form the outer peripheral short-circuit pattern 202 and the inner peripheral short-circuit pattern 203 on the piezoelectric element 201 from the beginning. Instead, at least the divided electrode pattern must be provided, and then polarization treatment must be performed to again form the inner and outer peripheral conduction electrode patterns.

Therefore, it is necessary to position and position the masks separately before and after the polarization process, and if the positioning is insufficient, the electrode pattern shown in FIG. 2 may be displaced or become non-conductive. become. Therefore, some kind of positioning means is required. According to the present invention, however, the positioning mark is made by utilizing a part of the electrode pattern on the one-body electrode pattern forming surface, and the manufacturing method is A difficult electrode pattern as shown in FIG. 2 can be easily formed. Although the positioning electrode pattern 103 is provided at two places in this embodiment,
Usually, there should be at least one place. Further, the shape of the positioning pattern is not limited to this embodiment, and it goes without saying that the shape of the positioning pattern corresponds to the present invention as long as a part of the one-body electrode pattern is used.

The reason why the divided electrode patterns having different polarization directions are electrically connected to each other by using the conductive electrode pattern on the inner and outer circumferences is as follows.
This is because the use of many piezoelectric elements is used as a vibrator, and it is necessary to suppress the loss of the vibrator by minimizing the number of connected lead wires.

FIG. 4 is a plan view showing a mask for realizing the electrode structure of the piezoelectric element manufactured by the method for manufacturing a piezoelectric element of the present invention shown in FIG. The mask base body 401 is provided with a round-hole-shaped one-body electrode forming hole portion 402, and two holes on the outer circumference of the hole portion are formed.
The positioning electrode pattern can be easily formed on the piezoelectric element by a simple setting that the positioning electrode forming holes 403 are provided at the locations.

In addition, since a guide frame that can guide the outer periphery of the piezoelectric elements 101, 201 is usually used on the mask base 401, the mask base 401 and the guide frame are combined to be called a mask jig. . Therefore, the hole for electrode formation
The positioning electrode pattern 103 formed by 403 should be set on the mask jig so as to match the positioning mark provided on a part of the guide frame when forming the electrode pattern of the opposing second surface. Becomes the actual piezoelectric element 101,
Positioning of 201 will be performed.

5 and 6 are views for explaining the method of manufacturing a piezoelectric element according to the present invention. Here, an example of an electrode structure of a piezoelectric element manufactured by the above-described method for manufacturing a piezoelectric element according to the present invention (shown in FIGS. 1 to 3) will be taken as an example, and an example of the manufacturing method will be sequentially described below. I will decide.

Inside the thin film forming apparatus (vacuum vapor deposition apparatus, sputtering apparatus, etc.) with the first surface of the piezoelectric element facing downward (electrode pattern formation surface side) on a mask jig having the mask shown in FIG.
Set to.

A one-body electrode pattern 102 and a positioning electrode pattern 103 as shown in FIG. 1 are formed.

The second surface (see FIG. 2) of the piezoelectric element is set downward on a mask jig having a mask capable of forming the divided electrode pattern a501 and the divided electrode pattern b502 shown in FIG. . At this time, the positioning electrode pattern 103 formed previously is aligned with the positioning mark provided on the guide frame of the mask jig to position the piezoelectric element, and then the divided electrode pattern is formed on the piezoelectric element 201. a501
And a divided electrode pattern b502 is formed.

Each divided electrode pattern a501 formed on the piezoelectric element 201
And b502 are polarized in appropriate directions. Here, the embodiment of the piezoelectric element manufactured by the manufacturing method of the present invention shows, as an example, a piezoelectric element applicable to an ultrasonic motor, and the polarization form is shown in each electrode pattern of FIG. +) And (-).

In addition, the polarization treatment of the piezoelectric element is performed by polarizing each electrode pattern between the one-body electrode pattern 102 formed on the first surface and the divided electrode patterns a501 and b502 formed on the second surface facing the one-body electrode pattern 102. The direct high voltage is applied according to the desired direction. In the figure, (+) means the first
A positive electric field is applied to the one-body electrode pattern 102 formed on the surface of (1), and (−) indicates that a negative electric field is applied.

After the polarization treatment, a cleaning treatment is carried out at an appropriate time, and then the second piezoelectric element is again placed on a mask jig having a mask capable of forming the outer peripheral short-circuit pattern 601 and the inner peripheral short-circuit electrode pattern 602 shown in FIG. Set so that the side of is on the lower side.
Also in this case, the peripheral electrode short circuit pattern 601 as shown in FIG. 6 and the inner short circuit pattern 601 as shown in FIG. 6 can be formed by a simple method such as aligning the positioning electrode pattern 103 previously formed with the positioning mark provided on the guide frame of the mask jig. The circumferential short-circuit pattern 602 can be formed without causing positional deviation from the previously formed divided electrode patterns a501 and b502, and as a result, the electrode pattern as shown in FIG. 2 can be easily and accurately formed. That will be the case.

FIG. 7 shows a principle diagram of a general vacuum vapor deposition apparatus as an example of a thin film forming apparatus for forming each electrode pattern of the piezoelectric element in the method for manufacturing a piezoelectric element of the present invention. The piezoelectric element 701 is set with the surface on which the electrode pattern is to be formed facing downward on the mask jig 702 formed of the mask substrate 401 and the guide frame which are vapor-deposited in the vacuum chamber 703, and placed on the evaporation source 704. Further, it is said that a thin film material 705 made of a material component for forming an electrode pattern is placed and the thin film material 705 is evaporated by means such as resistance heating or electron beam to form a desired electrode pattern on the lower surface of the piezoelectric element 701. Is an outline. At this time, in the piezoelectric element manufacturing method of the present invention, the thin film material 705 used for the piezoelectric element is, for example, chromium, nickel, gold or the like. Chromium is a contact metal with the piezoelectric element and is used in the sense of increasing the adhesion strength between the piezoelectric element and the electrode pattern.
Also, nickel is used for the purpose of improving the soldering of the lead wire to the electrode pattern and the like, and gold is used for the purpose of lowering the conduction resistance.

Further, the film thickness meter 706 is used to control the film thickness, and the shutter 707 is used to prevent vapor deposition from being deposited on the piezoelectric element 701 until stabilization.
Further, the vacuum pump 708 serves to keep the degree of vacuum in the vacuum chamber 703 constant.

FIG. 11 is a vertical sectional view of an ultrasonic motor using a piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention. According to the present invention, the electrode structure of the piezoelectric element shown in FIGS. 1 to 3 can be easily and accurately formed. Therefore, the piezoelectric element manufactured by the method for manufacturing a piezoelectric element of the present invention flexural traveling wave component It is effective to use it for an ultrasonic motor that utilizes the. The structure of an ultrasonic motor using a piezoelectric element manufactured by the method for manufacturing a piezoelectric element of the present invention will be described below.

A vibrating body 1102 formed by adhering the piezoelectric element 1101 is an elastic member made of metal or the like, and is supported on the central shaft 1103 by hammering or the like, and the central shaft 1103 is fixed to a fixed base 1104. The rotor 1105 is incorporated from above the vibrating body 1102 with the central shaft 1103 as a guide, and the vibrating body 1102 is installed by the pressure spring 1106 located above.
Is arranged so as to come into pressure contact with. Two leads
One of the 1107 is attached to the outer short-circuit electrode pattern 202, and the other one is attached to the inner short-circuit electrode pattern 203 by soldering or the like. Here, by applying signals having a time phase difference of approximately 90 ° to the two lead wires 1107,
The piezoelectric element 1101 and the vibrating body 1102 generate three mechanical traveling waves in the circumferential direction due to bending vibration, and the rotor 1105, which is in pressure contact with the vibrating body 1102, rotates.

By using the piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention, it is only necessary to attach two leads with the minimum number of lead wires, and even if the diameter is small and the electrode diameter is small, there is almost no displacement of the electrode pattern or eccentricity. In addition, an ultrasonic motor with extremely high efficiency and little variation becomes practical.

〔The invention's effect〕

As described above, according to the present invention, one electrode pattern is formed on one surface of the piezoelectric element having electrode patterns on both surfaces, and at the same time, one or more electrode pattern portions for positioning are provided, and the electrode pattern for positioning is used as a reference. By using a manufacturing method such as forming different electrode patterns on opposite surfaces as a plurality of times, it is possible to suppress misalignment and eccentricity of the complicated electrode pattern and facilitate positioning of the piezoelectric element on the mask jig. There is an effect such as. Further, by realizing the formation of the electrode pattern of the piezoelectric element by such a method for manufacturing a piezoelectric element according to the present invention, particularly when applied to a piezoelectric element for an ultrasonic motor, performance stabilization in diameter reduction and size reduction is achieved. Many effects such as high efficiency and high efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view (one-body electrode formation surface) showing an electrode structure of a piezoelectric element manufactured by a method for manufacturing a piezoelectric element according to the present invention, and FIG. 2 is a piezoelectric device manufactured by a method for manufacturing a piezoelectric element according to the present invention. FIG. 3 is a plan view showing the electrode structure of the element (divided electrode formation surface), FIG. 3 is a longitudinal sectional view showing the electrode structure of the piezoelectric element manufactured by the method for manufacturing a piezoelectric element according to the present invention, and FIG. Plan views showing a mask for forming an electrode of a piezoelectric element, FIGS. 5 and 6 are views for explaining a method of manufacturing a piezoelectric element according to the present invention, FIG. 7 is a principle diagram of a vacuum vapor deposition apparatus, and FIG. 8 is a conventional method. Fig. 9 is a plan view showing the electrode structure of the piezoelectric element (one-body electrode forming surface), Fig. 9 is a plan view showing the electrode structure of the conventional piezoelectric element (divided electrode forming surface), and Fig. 10 is the electrode of the conventional piezoelectric element. FIG. 11 is a plan view showing a forming mask, and FIG. 11 is a plan view showing a piezoelectric element manufacturing method according to the present invention. It is a longitudinal cross-sectional view of an ultrasonic motor using the manufactured piezoelectric element. 101,201,301,701,801,901,1101 ...... Piezoelectric element 102,802 ...... 1 body electrode pattern 103 …… Positioning electrode pattern 104,204,803,904 …… Center hole 202,601,902 …… Outer circumference short circuit electrode pattern 203,602,903 …… Inner circumference short circuit electrode pattern 302 …… 1 body electrode formation surface (No. No. 1 surface) 303 ...... Split electrode formation surface (second surface) 401, 1001 ...... Mask base 402, 1002 ...... Single body electrode formation hole 403 ...... Positioning electrode formation hole 404, 1003 ...... Mounting hole 501 …… Split electrode pattern a 502 …… Split electrode pattern b 702 …… Mask jig 1102 …… Vibrator 1103 …… Center axis 1104 …… Fixed base 1105 …… Rotor 1106 …… Pressure spring 1107 …… …Lead

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Kitamura 6-31-1, Kameido, Koto-ku, Tokyo Seiko Denshi Kogyo Co., Ltd. (56) Reference JP 58-6189 (JP, A) Showa 60-44495 (JP, U) Actually opened Showa 51-66756 (JP, U)

Claims (2)

[Claims] 1. A method of manufacturing a piezoelectric element having electrode patterns on both surfaces, wherein the step of forming one body electrode and a positioning pattern on a first surface, and the positioning pattern formed on the first surface as a reference, A step of forming a plurality of electrode patterns on a second surface opposite to the first surface; and a plurality of electrodes formed on the second surface with respect to a one-piece electrode formed on the first surface A step of performing polarization processing such that two adjacent electrode patterns are set as one set and the sets are set in opposite directions, and the second surface is based on the positioning pattern formed on the first surface. And a step of forming conductive electrode patterns so that every other plurality of electrode patterns are short-circuited, and a method for manufacturing a piezoelectric element. 2. A method of manufacturing a piezoelectric element having electrode patterns on both sides, the step of forming a single electrode on a first surface, and the step of forming a plurality of electrode patterns on a second surface opposite to the first surface. A step of forming, and for each one-body electrode formed on the first surface, each pair of the plurality of electrode patterns formed on the second surface are adjacent to each other, The piezoelectric device according to claim 1, further comprising: a step of performing polarization processing in opposite directions; and a step of forming conductive electrode patterns so as to short-circuit every other plurality of electrode patterns on the second surface. Device manufacturing method.