JPH09266333A - Piezo-electric transformer and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the wear out resistance of a thick electrode area near a node point while maintaining the separation resistant properties of a surface electrode and a piezo-electric body in a piezo-electric transformer in structure in which the area near the node point of vibration out of an electrode on the surface of a transformer device is arranged to be thicker than the other electrode portion. SOLUTION: The formation of an electrode consists of a first process which provides thick conductive projections 21 and 31 having a high degree of wear out resistance and a second process which forms thin conductive thin films 20 and 30 which cover the projection and their surrounding areas. Or the conductive thin films 20 and 30 having a lower degree of wear out resistance are formed at first and then preferably, a thick projection having a higher degree of wear out resistance be formed near the node point of vibration on these thin films. Low temperature baking is employed for a conductive paste so as to form the thin films 20 and 30. The projections 21 and 31 are formed by baking the conductive paste at a high temperature or by fixedly mounting a metal small piece with plating or a conductive bonding agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric transformer used in, for example, a high voltage power supply device and a method for manufacturing the same, and more particularly to a method for forming an electrode (hereinafter referred to as a surface electrode) formed on the surface of a piezoelectric plate. Is.

[0002]

2. Description of the Related Art Piezoelectric transformers apply an AC voltage from the outside to a transformer element in which an input electrode and an output electrode are formed on a main surface of a thin plate-shaped piezoelectric body via the input electrode on the main surface. It is a kind of vibrator having a structure in which a voltage generated in a piezoelectric body as a result of vibration is taken out from an output electrode. The input and output surface electrodes formed on the main surface of the piezoelectric body should not interfere with the vibration of the piezoelectric body, should not be worn by vibration or external force, and should not be peeled off from the piezoelectric body. , Etc. must be provided.

One of the electrode forming methods for reducing the degree of inhibition against vibration against the above-mentioned conditions that the surface electrode should have is disclosed in Japanese Utility Model Laid-Open No. 60-40124. In the piezoelectric vibrator described in the above publication, of the surface electrodes formed on the piezoelectric body, only the portion near the node of the main vibration of the piezoelectric body is made thicker than the other portions, and the weight of the electrode is made smaller than in the case where the entire electrode is thickened. By reducing
The inhibition of vibration by the electrode is reduced. In order to form such an electrode, first, a silver paste for an electrode is applied to a predetermined portion of the piezoelectric body (this portion corresponds to the entire electrode to be formed and includes node points of vibration of the piezoelectric body). Screen print. Next, the conductive paste is printed again in an appropriate shape on the portion corresponding to the node point of the vibration in the screen-printed silver paste film. In other words, the vibration node point and its vicinity are printed twice. Then, the whole is baked at once to form an electrode. In this way, the surface electrode having a structure in which the overprinted node points and the vicinity thereof are thick and the other electrode portions are thin is formed.

On the other hand, the invention aimed at improving the bonding strength between the electrode and the piezoelectric body in order to satisfy the difficult peeling property from the piezoelectric body due to vibration or external force among the conditions that the surface electrode should have. Is disclosed in JP-A-5-335861. According to the electrode forming method described in this publication,
The silver paste is screen-printed on the portion where the electrode is to be formed on the main surface of the piezoelectric body, and then 520-5 in the atmosphere.
The electrode is formed by firing at a relatively low temperature of 80 ° C. In this method, the silver paste is conventionally generally fired at a relatively high temperature of about 650 to 700 ° C., but by firing at a temperature lower than that, a large number of pores are formed in the fired electrode. The anchor effect of the pores improves the bonding strength between the surface electrode and the piezoelectric body.

By the way, even if you get tired of the explanation so far,
This is a view of the piezoelectric transformer viewed from the transformer element alone. However, in order to put the piezoelectric transformer into practical use, it is necessary to connect an external circuit to an electrode on the surface of the transformer element and to insulate the transformer element from other circuit elements. A so-called mounting structure is required, such as housing the package in a package having a terminal for connection with the outside. Further, such a mounted piezoelectric transformer has a problem of vibration inhibition due to the mounting structure, in addition to the above-described inhibition of vibration due to the surface electrode, in other words, an inhibiting factor included in the transformer element itself. Inhibition of vibration caused by such a mounting structure, in particular, a method of mounting a piezoelectric transformer for the purpose of improving the inhibition of vibration due to contact between the lead terminal on the package side and the surface electrode on the transformer element side,
It is described in Japanese Patent Application No. 7-39912 by the same assignee as the assignee of the invention of this application. FIG. 6 shows an exploded perspective view of a piezoelectric transformer using the spring contact structure according to the present invention. A sectional view is shown in FIG. FIG. 7 shows a cross section taken along the line AA in FIG.

Referring to FIGS. 6 and 7, the piezoelectric transformer element 5
1 is stored in the space surrounded by the upper case 41A and the lower case 41B. On the upper surface of the transformer element 51, two input electrodes 52A located at both ends in the longitudinal direction and a stripe-shaped output electrode 53 located in the center.
A total of three surface electrodes A are formed independently. A total of three surface electrodes are formed on the lower surface of the transformer element 51 at positions facing the respective electrodes on the upper surface. Upper case 4
1A horizontally from its side wall to the center of the upper input electrode 52A of the transformer element 51, and the upper lead terminal 42A.
Is growing. Then, it is bent in a V shape toward the transformer element 51 side near the tip, and the input electrode 52 is bent at the contact portion 54A.
I am in contact with A. Similarly, the lower lead terminal 42B extends horizontally from the side wall of the lower case 41B to the center of the input electrode 52B on the lower surface side of the transformer element 51, and the tip is bent to contact the input electrode 52B at the contact portion 54B. .
The upper and lower lead terminals 42A and 42B are respectively formed by processing a tin-plated phosphor bronze plate material,
It has spring properties and is embedded by the insert molding method so as to penetrate through the side walls of the upper and lower cases 41A and 41B in and out. The portion extending to the outside of the side wall is the connecting portion with the outside. The upper lead terminal and the lower lead terminal having such a structure are the transformer element 51.
Is also provided on the other input electrode and output electrode.

When such a package is used, not only a contact structure (contact between the surface electrode of the transformer element and a lead terminal on the package side) which does not hinder the vibration of the transformer element can be obtained, but also the transformer itself is assembled. It is possible to realize a piezoelectric transformer that is excellent in ease of mounting and mountability when realizing a high-voltage power supply device together with other circuit elements.

[0008]

As described above, in the piezoelectric transformer, the surface electrode formed on the transformer element and the mounting structure when housed in the package do not hinder the vibration of the transformer element, and It is important that the surface electrode does not wear or peel off from the piezoelectric body due to vibration or external force. Further, according to the above-mentioned three inventions, respectively, prevention of vibration inhibition by the surface electrode (Japanese Utility Model Laid-Open No. 60-40124) and improvement of difficulty of peeling of the surface electrode from the piezoelectric body (Japanese Patent Laid-Open No. 3-335861). And the prevention of vibration inhibition due to the mounting structure (Japanese Patent Application No. 7-39912). Further, by combining the above three inventions, a piezoelectric transformer housed in a package having a lead terminal exhibiting a spring property, wherein the vibration is not hindered by the surface electrode of the transformer element or the mounting structure, It can be expected that a piezoelectric transformer having excellent bonding strength between the piezoelectric body and the piezoelectric body can be obtained.

However, the piezoelectric transformer having a structure in which it is housed and mounted in a package having a spring type lead terminal, which is obtained by combining the three inventions, still has a problem of abrasion resistance of surface electrodes. The description is given below.

First, in the electrode forming method disclosed in Japanese Utility Model Laid-Open No. 60-40124, when it is attempted to form the electrode thickness in the vicinity of the node point to be thicker than the electrode thickness in other portions, first, the entire electrode is made equivalent. The conductive paste is screen-printed on the part to be dried and then the conductive paste is screen-printed again on the part corresponding to the node point of the vibration on the conductive paste film, and then the whole is baked to surface. The electrodes are formed at once. According to this method, the firing conditions are the same for the thick conductive paste film near the node point and the thin conductive paste film in other portions. From the characteristics of the piezoelectric transformer, it is more advantageous to lower the firing temperature of the electrode paste film. This is because when the firing temperature is high, the bonding strength between the surface electrode and the piezoelectric body after firing is lowered, and the electrode is likely to peel. On the other hand, from the viewpoint of wear resistance of the electrode, it is advantageous to raise the firing temperature to advance the firing state. That is, there is a trade-off between the difficult peeling property and the abrasion resistance of the surface electrode with respect to the firing temperature, and it is difficult to make both of them compatible with one firing temperature.

Next, in JP-A-5-335861, in order to improve the bonding strength between the surface electrode and the piezoelectric body, the firing temperature of the conductive paste for electrodes is lowered than usual to suppress the firing state. The electrode after firing is made porous. By doing so, the peeling resistance of the surface electrode is improved, but since the firing of the electrode is insufficient, after all, as in the electrode forming method described above, the contact portion with the spring-like lead terminal on the package side Wear of the electrodes is likely to occur.

In a piezoelectric transformer having a spring contact structure as described in Japanese Patent Application No. 7-39912, the contact between the lead terminal on the package side and the surface electrode of the transformer element is located at the node point of the vibration of the transformer element. So that
The wear of the electrode due to the contact between the surface electrode and the lead terminal is made small.However, the above-mentioned node point is a node point in the vibration in the longitudinal direction. Even at the contact point, it vibrates in the thickness direction. Therefore, there is a risk that the electrodes may be worn during long-time driving. Further, since the contact is not a fixed contact, when vibration is applied from the outside, the contact may slide and the electrode may be worn.

Accordingly, the present invention is a method for manufacturing a piezoelectric transformer having a structure in which only the thickness of the surface electrodes formed on the transformer element in the vicinity of the node point of vibration is made thicker than the other electrode portions. An object of the present invention is to provide a manufacturing method capable of improving abrasion resistance in a thick electrode portion near a node point while ensuring difficult peeling between a surface electrode and a piezoelectric body.

[0014]

A piezoelectric transformer according to the present invention is provided with at least one or more of a long plate-shaped piezoelectric body which is oscillated by being applied with an AC voltage from the outside over the longitudinal direction. Drive region and at least one or more power generation regions that generate a voltage according to the vibration, and the input electrode or the piezoelectric body for applying the AC voltage to the surface of each region of the piezoelectric body. In a piezoelectric transformer provided with an output electrode for taking out a voltage generated in each of the electrodes, each of the electrodes is formed of a thick conductive layer having high abrasion resistance formed at and around a node point of vibration generated in the piezoelectric body. And a thin conductive thin film having a low degree of wear resistance and covering the protrusion and the periphery thereof.

The above-mentioned piezoelectric transformer has at least one drive region which causes an external AC voltage to generate vibration in the piezoelectric body over the longitudinal direction of the long plate-shaped piezoelectric body, and the vibration. Is divided into at least one or more power generation regions that generate a voltage according to, and on the surface of each of the regions of the piezoelectric body,
In a method of manufacturing a piezoelectric transformer including an electrode forming step of providing an input electrode for applying the AC voltage or an output electrode for taking out a voltage generated in the piezoelectric body, the electrode forming step includes Providing thick conductive protrusions with high abrasion resistance at and around the node point 1
And a second step of forming a thin conductive thin film having a low degree of abrasion resistance and covering the protrusion and the periphery thereof, and are manufactured by the manufacturing method.

In the first step, after forming a thick silver paste layer containing silver particles, the temperature is 700 ° C. or higher and 740 ° C.
In the second step, a silver paste layer containing silver particles is thinly formed, and then baked at a temperature of 600 ° C. or higher and 640.
An electrode is formed by firing at a temperature of not higher than ° C.

Alternatively, in the first step, after the silver / palladium paste layer containing silver / palladium particles is formed thickly, it is baked at a temperature of 830 ° C. or higher and 870 ° C. or lower, and in the second step, silver / palladium paste layer is formed. After thinly forming a silver / palladium paste layer containing palladium particles, the temperature is 700 ° C or higher,
The electrode is formed by firing at 740 ° C. or lower.

Further, the piezoelectric transformer of the present invention has at least one or more driving regions which are provided with an AC voltage from the outside and generate vibrations in the piezoelectric body over the longitudinal direction of the long plate-shaped piezoelectric body. , The voltage generated in the input electrode or the piezoelectric body for applying the AC voltage to the surface of each region of the piezoelectric body, which is divided into at least one power generation region that generates a voltage according to the vibration In the piezoelectric transformer provided with an output electrode for taking out, each of the electrodes is a thin conductive thin film having a low degree of wear resistance formed in a portion including a node point of vibration generated in the piezoelectric body, It is characterized by comprising the node point on the thin film and a thick conductive projection having a high degree of abrasion resistance formed in the vicinity thereof.

The above-mentioned piezoelectric transformer has at least one or more drive regions that generate an oscillation in the piezoelectric body when an AC voltage is applied from the outside over the longitudinal direction of the long plate-shaped piezoelectric body, and the vibration. Is divided into at least one or more power generation regions that generate a voltage according to, and on the surface of each of the regions of the piezoelectric body,
In a method of manufacturing a piezoelectric transformer including an electrode forming step of providing an input electrode for applying the AC voltage or an output electrode for taking out a voltage generated in the piezoelectric body, the electrode forming step includes A first step of forming a thin conductive thin film having a low degree of abrasion resistance in a portion including a node point, and the node point on the thin film and the vicinity thereof,
And a second step of forming a thick conductive protrusion having a high degree of abrasion resistance.

In the first step, the conductive paste layer containing metal particles is thickly formed and then fired, and then the second step is performed.
In the step (1), an electrode is formed by masking a portion other than the portion where the protrusion is to be formed and plating the portion where the protrusion is to be formed with gold, nickel or chromium.

Alternatively, in the first step, after the conductive paste layer containing metal particles is formed thick, firing is performed,
In the second step, an electrode is formed by fixing a small piece of gold, nickel, or chromium to a node point of the vibration on the thin film with a conductive adhesive.

According to the present invention, only the vibration node point and its vicinity of the surface electrode are thickened. Therefore, the inhibition of vibration by the electrodes is small. Moreover, since the wear resistance of the thick portion (protrusion) near the node point is high, the wear resistance of this portion is high. On the other hand, since the thin portion other than the vicinity of the node point is not completely fired by firing at a relatively low temperature, the bonding strength with the piezoelectric body is high.

[0023]

Next, some embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a manufacturing process of a piezoelectric transformer according to a first embodiment of the present invention. In the present embodiment, the piezoelectric transformer element 1 whose perspective view is shown in FIG. 2 is manufactured by the manufacturing process shown in FIG. 1, and is housed in a package having a lead terminal of a spring contact structure whose sectional view is shown in FIG. After mounting, a packaged piezoelectric transformer 40 was obtained.

First, referring to FIG. 2, the transformer element 1 shown in this figure has a total of three input electrodes 20, 20 and one output electrode 30 on the upper surface of a long plate-shaped piezoelectric ceramic plate 10. It has a surface electrode. The input electrodes 20 and 20 are formed on both ends of the ceramic plate 10 in the longitudinal direction with a large area. The output electrode 30 has two input electrodes 2 at the center of the ceramic plate 10 in the longitudinal direction.
It is sandwiched between 0 and 20 and provided in a strip shape extending in the width direction. Each of the input electrodes 20 and 20 and the output electrode 30 has a small contact protrusion 21, 21, 31 having a square planar shape at the center of each electrode. The position of each contact protrusion corresponds to the node point of the longitudinal vibration of the transformer element 1. Although not shown in the figure, the lower surface of the transformer element 1 also has a total of three surface electrodes having a contact protrusion in the center at each position facing the electrode on the upper surface. The region of the ceramic plate 10 where the input electrode 20 is formed is usually called the drive unit 2, and the region between the input electrode 20 and the output electrode 30 is called the power generation unit 3.

The present inventor manufactured the piezoelectric transformer element 1 shown in FIG. 2 as follows. First, using a piezoelectric ceramic powder (trade name: NEPEC8: Tokin Co., Ltd.), width 10.0 mm x length 42.0 mm x thickness 1.0 m
Ceramic plate 10 that is formed and processed into a long plate of m and fired
Was obtained (FIG. 1 (a)).

Next, silver paste was screen-printed and baked at the positions where the contact protrusions 21, 21, 31 were to be formed (FIG. 1 (b)). The firing conditions are a temperature of 700 to 740 ° C.,
The time is 10 minutes. The obtained protrusion has an area of 1 mm ² .
The thickness is 20 ± 5 μm.

Next, silver paste was screen-printed on the portions where the input electrodes 20 and 20 and the output electrode 30 were to be formed and baked (FIG. 1 (c)). The firing conditions are a temperature of 600
˜640 ° C., time 10 minutes. The thickness of each obtained electrode is 5 ± 2 μm.

After that, the power generation section 3 was polarized using a polarization jig. The polarization was performed by applying an electric field of 0.5 to 0.7 kV / mm in air at a temperature of 300 to 350 ° C., lowering the temperature to 100 ° C. with the electric field applied, and then cutting off the applied electric field. .

Subsequently, the drive section 2 was polarized. Polarization is performed in a silicone oil at a temperature of 100 to 200 ° C. with an electric field of 2 to
It was performed by a method of applying 3 kV / mm. In this way, the transformer element 1 was obtained.

Finally, the obtained transformer element 1 was housed in a package having a spring type lead terminal to complete the packaged piezoelectric transformer of the present embodiment shown in the sectional view of FIG. The package in the present embodiment is the same as the package used in the conventional packaged piezoelectric transformer shown in FIG. 7, and the upper and lower lead terminals have contact points 43A and 43B at the bent portions of the tips. Then, the contact protrusions 21, 21, 3 provided in the surface electrode of the transformer element
1 is in contact with each.

The packaged piezoelectric transformer according to the present embodiment showed good transformer characteristics with an efficiency of 97% and a step-up ratio of 15 times. Moreover, as a result of evaluating the reliability of the contacts, there was no problem even when continuously driven for up to 2000 hours.

Next, FIG. 4 shows the results of measuring the efficiency of the piezoelectric transformer by changing the thicknesses of the input electrodes 20, 20 and the output electrode 30. Referring to FIG. 4, although the efficiency increases as the thickness of the surface electrode decreases, the thickness of the electrode capable of stably forming a thin print film by the screen printing method was examined, and as a result, 5 ± 2 μm Was the limit for stable film formation.

FIG. 5 shows the results of measuring the efficiency of the piezoelectric transformer by changing the firing temperatures of the input electrodes 20, 20 and the output electrode 30. Referring to FIG. 5, the efficiency improves as the firing temperature of the surface electrode decreases. However, as a result of examining the firing state of the electrode, the silver paste was hardly fired at a temperature lower than 600 ° C.
The firing temperature of ˜640 ° C. was the limit for stable firing while keeping the efficiency of the piezoelectric transformer sufficiently high.

Further, in the present embodiment, the contact protrusions 21, 21, 31 in the surface electrode were fired while changing the thickness and firing temperature, and the reliability of the contact was investigated. First, the firing temperature is 70
When the temperature was lower than 0 ° C., when the thickness of the contact protrusion was 5 to 15 μm, the electrode was worn (5 to 10 μm) by 2000 hours and the contact failure occurred. The defective rate was 30%. On the other hand, in the case where the thickness of the contact protrusion was increased to 15 to 25 μm, the contact failure occurrence rate was improved to 5%. However, even in this case, wear of the electrodes occurred similarly.

Next, the reliability of the contacts was investigated for those fired in the temperature range of 700 to 740 ° C. while changing the thickness of the contact protrusions in the same manner. In this case, the wear of the electrode was high and 1 μm or less and was hardly observed. However, in terms of workability of screen printing, the thickness of the contact protrusion is 15
It was the best when it was ˜25 μm.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
As a second embodiment, the surface electrode was formed by using a silver / palladium alloy paste instead of the silver paste in the first embodiment. The silver-palladium alloy paste used had an Ag: Pd ratio of 70:30. The firing of the contact protrusions 21, 21, 31 is performed under the conditions of a temperature of 830 to 870 ° C. and a time of 10 minutes.
Was baked at a temperature of 700 to 740 ° C. for 10 minutes.

The characteristics of the obtained packaged piezoelectric transformer are as follows.
Embodiment)). Also, 100% silver
As a result of investigating the reliability of the contact in the same manner as in the case of the electrode product, no wear of the electrode was observed until 4000 hours, and the reliability of the contact was higher than that of the 100% silver electrode product.

(Third Embodiment) In the present embodiment,
Plating was used for the contact protrusions. That is, first, a thickness of 5 ± 2 μm is screen-printed on the portions on the ceramic plate where the input electrodes 20, 20 and the output electrode 30 are to be formed.
The silver paste thin film or the silver-palladium alloy thin film of was formed and baked. The forming method is the same as in the first embodiment or the second embodiment.

Then, the portions other than the portions where the contact protrusions 21, 21, 31 are to be formed are masked, and the contact protrusions are nickel-plated with a thickness of 15 μm by the electric field plating method.

The characteristics of the thus-packaged piezoelectric transformer obtained were at the same level in efficiency and step-up ratio as those of the first and second embodiments.

(Fourth Embodiment) In the present embodiment,
Small metal pieces were used for the contact protrusions. That is, first, a thickness of 5 ± 2 μm is screen-printed on the portions of the ceramic plate where the input electrodes 20, 20 and the output electrode 30 are to be formed.
m silver paste thin film or silver-palladium alloy thin film was formed and fired. The forming method is the same as in the first embodiment or the second embodiment.

Next, a small piece of nickel of 1 mm ² was adhered to the portion where the contact protrusions 21, 21, 31 were to be formed. An epoxy conductive adhesive is used for the adhesion, and the temperature is 170 ° C.
It was cured under the condition of time of 15 minutes.

The characteristics of the packaged piezoelectric transformer obtained in this manner were equivalent to those of the first and second embodiments in terms of efficiency and step-up ratio. Also, the contact reliability was investigated, but no electrode wear was observed.

Up to this point, the piezoelectric transformer housed and mounted in the spring contact structure package has been described as an example, but instead of the lead terminal, the lead wire is directly joined to the vicinity of the contact of the surface electrode by soldering or the like. It may have a different structure. In this case, there is an effect that it is possible to further alleviate the vibration inhibition when the transformer is driven.

Further, the transformer element has been described as an example in which two sets of input electrodes are provided, but one set may be used as long as the structure can apply an AC voltage to the piezoelectric body. There may be two or more sets of output electrodes.

[0047]

As described above, at least one input electrode and at least one output electrode are arranged to face each other in the longitudinal direction of the long plate-shaped piezoelectric body in the vicinity of the contact point of the piezoelectric transformer. According to the method for manufacturing a piezoelectric transformer of the present invention, in which the electrodes are thinly formed except for the vicinity of the contacts and the whole is fired at a temperature lower than the previous firing temperature after the thick contacts are formed and fired, the spring contacts When the piezoelectric transformer is mounted by the structure, the reliability is high, there is no problem of abrasion resistance of the contact portion, and sufficient transformer characteristics are obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a piezoelectric transformer element according to a first embodiment of the present invention in the order of steps.

FIG. 2 is a perspective view of the piezoelectric transformer element according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the piezoelectric transformer element according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a thickness of a surface electrode and a transformer efficiency in a piezoelectric transformer including a spring contact structure package according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a firing temperature of a surface electrode and a transformer efficiency in a piezoelectric transformer including a spring contact structure package according to the first embodiment of the present invention.

FIG. 6 is an exploded perspective view of a conventional piezoelectric transformer including a spring contact structure package.

7 is a cross-sectional view of the piezoelectric transformer shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 transformer element 2 drive part 3 power generation part 10 ceramic plate 20, 20A, 20B input electrode 30 output electrode 21, 31 contact protrusion 40 piezoelectric transformer 41A, 41B case 42A, 42B lead terminal 43A, 43B contact part 51 transformer element 52A input electrode 53A Output electrode 54A, 54B Contact part

Claims (14)

[Claims] 1. A piezoelectric body having a long plate shape and at least one or more drive regions which are applied with an AC voltage from the outside to cause vibrations in the piezoelectric body, and a voltage corresponding to the vibrations. To generate at least one power generation region, and on the surface of each region of the piezoelectric body, an input electrode for applying the AC voltage or an output electrode for extracting the voltage generated in the piezoelectric body. In the provided piezoelectric transformer, each of the electrodes includes a node point of vibration generated in the piezoelectric body and a thick conductive protrusion having high abrasion resistance formed in the vicinity thereof and the protrusion and its periphery. A piezoelectric transformer comprising a thin conductive thin film having a low abrasion resistance and covering the thin film. 2. A piezoelectric body having a long plate shape, at least one or more drive regions that generate an oscillation in the piezoelectric body by being applied with an AC voltage from the outside along a longitudinal direction, and a voltage according to the oscillation. To generate at least one power generation region, and on the surface of each region of the piezoelectric body, an input electrode for applying the AC voltage or an output electrode for extracting the voltage generated in the piezoelectric body. In the provided piezoelectric transformer, each of the electrodes includes a thin conductive thin film with low abrasion resistance formed in a portion including a node point of vibration generated in the piezoelectric body, and the node point on the thin film. A piezoelectric transformer, comprising: a thick conductive protrusion having a high degree of wear resistance formed in the vicinity thereof. 3. The piezoelectric transformer according to claim 1, wherein the protrusion and the thin film are formed by baking a conductive paste film, and the protrusion is formed by baking at a higher temperature than the thin film. Piezoelectric transformer to do. 4. The piezoelectric transformer according to claim 3, wherein the protrusion and the thin film are obtained from a silver paste containing silver particles, and the protrusion has a silver paste film temperature of 7.
The thin film is baked at a temperature of 00 ° C or higher and 740 ° C or lower, and the thin film is a silver paste film having a temperature of 600 ° C or higher and 640 ° C.
A piezoelectric transformer characterized by being fired below. 5. The piezoelectric transformer according to claim 3, wherein the protrusion and the thin film are obtained from a silver / palladium alloy paste containing silver / palladium alloy particles.
The protrusion is formed of a silver-palladium alloy paste film at a temperature of 83.
A piezoelectric transformer, wherein the piezoelectric thin film is fired at 0 ° C. or higher and 870 ° C. or lower, and the thin film is a silver paste film fired at a temperature of 700 ° C. or higher and 740 ° C. or lower. 6. The piezoelectric transformer according to claim 2, wherein the thin film is formed by firing a conductive paste film containing metal particles, and the protrusion is a plated layer of gold, nickel or chromium. Piezoelectric transformer characterized by. 7. The piezoelectric transformer according to claim 2, wherein the thin film is formed by firing a conductive paste film containing metal particles, and the protrusion is conductively bonded to a small piece of gold, nickel or chromium. A piezoelectric transformer characterized by being fixed by an agent. 8. A piezoelectric body in the form of a long plate extending at least in the longitudinal direction, and at least one or more drive regions that are given an external AC voltage to cause vibration in the piezoelectric body, and a voltage depending on the vibration. To generate at least one power generation region, and on the surface of each region of the piezoelectric body, an input electrode for applying the AC voltage or an output electrode for extracting the voltage generated in the piezoelectric body. In the method of manufacturing a piezoelectric transformer including an electrode forming step, a first step in which the electrode forming step forms thick conductive protrusions having high abrasion resistance at and around a node point of vibration generated in the piezoelectric body. And a second step of forming a thin conductive thin film having a low degree of wear resistance and covering the protrusion and the periphery thereof, the method of manufacturing a piezoelectric transformer. 9. A piezoelectric body in the form of a long plate, and at least one or more drive regions that generate an oscillation in the piezoelectric body by being applied with an AC voltage from the outside along a longitudinal direction, and a voltage depending on the oscillation. To generate at least one power generation region, and on the surface of each region of the piezoelectric body, an input electrode for applying the AC voltage or an output electrode for extracting the voltage generated in the piezoelectric body. In the method for manufacturing a piezoelectric transformer including an electrode forming step, the first electrode forming step forms a thin conductive thin film having low abrasion resistance at a portion including a node point of vibration generated in the piezoelectric body. 2. A method for manufacturing a piezoelectric transformer, comprising: a step; and a second step of forming a thick conductive projection having a high degree of wear resistance on the node point and its vicinity on the thin film. 10. The method for manufacturing a piezoelectric transformer according to claim 8, wherein in the first step, after forming a thick silver paste layer containing silver particles, firing is performed at a temperature of 700 ° C. or higher and 740 ° C. or lower, In the second step, a method for manufacturing a piezoelectric transformer is characterized in that after a silver paste layer containing silver particles is thinly formed, firing is performed at a temperature of 600 ° C. or higher and 640 ° C. or lower. 11. The method for manufacturing a piezoelectric transformer according to claim 8, wherein in the first step, after forming a thick silver / palladium paste layer containing silver / palladium particles, the temperature is set to 830 ° C. or higher and 870 ° C. or lower. Firing, and in the second step, after the silver / palladium paste layer containing silver / palladium particles is thinly formed, firing is performed at a temperature of 700 ° C. or higher and 740 ° C. or lower. 12. The method for manufacturing a piezoelectric transformer according to claim 9, wherein in the first step, a conductive paste layer containing metal particles is thinly formed and then fired, and in the second step, the conductive paste layer is baked. A method for manufacturing a piezoelectric transformer, characterized in that a portion other than a portion where a protrusion is to be formed is masked and the portion where the protrusion is to be formed is plated with one of gold, nickel and chromium. 13. The method for manufacturing a piezoelectric transformer according to claim 9, wherein in the first step, a conductive paste layer containing metal particles is thinly formed and then baked, and in the second step, the conductive paste layer is baked. A method for manufacturing a piezoelectric transformer, characterized in that a small piece of gold, nickel or chromium is fixed to a node point of the vibration on the thin film with a conductive adhesive. 14. A piezoelectric transformer according to any one of claims 1 to 7, and a package having the piezoelectric transformer housed therein, each electrode being located on a main surface of the piezoelectric transformer from a side wall thereof. A package having a plurality of lead terminals having a spring property and extending horizontally upward, and a protrusion provided at a node point of vibration of each electrode on the surface of the piezoelectric transformer, and a tip portion of the lead terminal of the package. A piezoelectric transformer in a package that has a structure in which and are contacted by spring pressure.