JP2002185057A - Piezoelectric transformer and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric transformer that improves booster ratio and efficiency, and also increases a yield, and to provide a method for manufacturing the piezoelectric transformer. SOLUTION: In the piezoelectric transformer 10, a first electrode 13a is formed on the front surface of piezoelectric ceramics 11, and a second electrode 13b and an extraction electrode 14 insulated from the second electrode 13b are formed on the back surface of the piezoelectric ceramics 11. In this case, polarization treatment is carried out between the first and second electrodes 13a and 13b, and the first electrode 13a is connected to the extraction electrode 14 by a continuity member 15.

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 various power supply circuits for generating high voltage and a method of manufacturing the same.

[0002]

2. Description of the Related Art Piezoelectric transformers can be (1) reduced in size, (2) have no danger of burning, etc., (3) have a high step-up ratio, and (4) compared to wound-type electromagnetic transformers. It has many advantages such as no magnetic field generation. For this reason, piezoelectric transformers are used, for example, in lighting circuits for backlights (cold-cathode tubes) that illuminate a liquid crystal display panel in a liquid crystal display widely used as a display of a personal computer.

As such a piezoelectric transformer, what is generally called a Rosen type is widely used.
The Rosen-type piezoelectric transformer uses, for example, a rectangular plate-shaped piezoelectric ceramic, and has one half in the longitudinal direction of the piezoelectric ceramic as a driving unit and the other half as a power generating unit. A pair of input electrodes is formed in the thickness direction, and an output electrode is formed on an end surface of the power generation unit. The drive unit is polarized in the thickness direction of the piezoelectric ceramic, and the power generation unit is polarized in the longitudinal direction of the piezoelectric ceramic. When a predetermined AC voltage is applied between the input electrodes, the drive unit excites longitudinal vibration in the thickness direction of the piezoelectric ceramic. Then, in the power generation unit, vibration is excited in the longitudinal direction, and strong mechanical vibration occurs. Thus, a high AC voltage can be obtained at the output electrode of the power generation unit by the piezoelectric effect.

A typical form of such a piezoelectric transformer is a Rosen type piezoelectric transformer. Assuming that the mechanical resonance wavelength in the longitudinal direction is λ, the vibration of the Rosen-type piezoelectric transformer is excited in a vibration mode of λ / 2, λ or an integral multiple thereof, so that a node where the vibration displacement becomes zero in the longitudinal direction for each vibration mode. A point and a maximum point occur.

As described above, since a high voltage is generated in the piezoelectric transformer, the piezoelectric transformer is mounted on a circuit board or the like in a state of being housed in a resin case in consideration of safety. Here, when the piezoelectric transformer is housed in a case, a method of supporting the piezoelectric transformer at a node point so as not to hinder the vibration of the piezoelectric transformer is generally used.

In order to further reduce the size of the case, as shown in a perspective view of FIG. 6, a driving portion is provided with one input electrode 97a formed on one main surface 99a of the piezoelectric ceramic 91 and the piezoelectric ceramic 91 as a piezoelectric ceramic. The electrode lead 98a is drawn out to the other main surface 99b through the electrode lead 98a formed on the side surface 99c of the 91, and the electrode lead 98a is made conductive with the extraction electrode 98b formed on the main surface 99b. A piezoelectric transformer 90 having an electrode shape for extracting a terminal from an input electrode 97b and a lead electrode 98b is known. The input electrodes 97a and 97b, the electrode lead 98a, the extraction electrode 98b, and the output electrode 96
It was printed using a screen printing method and was formed by simultaneous firing.

[0007]

However, in such a piezoelectric transformer 90, the input electrode 97a and the lead-out electrode 98b have already been used when performing the polarization processing in the driving section.
, The distance between these electrodes (the width of the gap 95) must be sufficiently large so that dielectric breakdown does not occur between the input electrode 97b and the extraction electrode 98b. In this case, the electrode area of the input electrode 97b on the main surface side on which the extraction electrode 98b is formed is eroded, so that the entire effective area of the input electrode cannot be made large, and the boosting ratio can be reduced. There was a problem that can not be obtained.

The portion of the piezoelectric ceramic 91 where the extraction electrode 98b and the input electrode 97a face each other is an unpolarized portion, which obstructs the vibration of the piezoelectric transformer 90 and lowers the efficiency (energy conversion efficiency). There was a problem. Further, when printing the electrode lead 98a, a conduction failure due to a positional shift between the electrode lead 98a and the extraction electrode 98b is likely to occur, and the main surfaces 99a and 99b
In the edge portion of the piezoelectric ceramic 91 where the and the side surface 99c intersect, the printed surfaces are orthogonal to each other, so that the printed pastes are likely to overlap with each other insufficiently, and since the printed paste is easily peeled off after drying, sufficient conduction is achieved. There was a problem that the yield could not be secured and the yield was reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a piezoelectric transformer having an improved boost ratio and efficiency and an improved yield, and a method of manufacturing the same. I do.

[0010]

According to the present invention, there is provided a piezoelectric transformer having a pair of input electrodes formed at predetermined positions on the front and back main surfaces of a piezoelectric ceramic, wherein the input electrodes are: A first electrode formed on the front surface of the piezoelectric ceramic, a second electrode formed on the back surface of the piezoelectric ceramic, and a second electrode formed on the back surface of the piezoelectric ceramic.
An extraction electrode provided electrically insulated from the electrode,
Connecting the first electrode and the extraction electrode;
A piezoelectric transformer, comprising: an electrode and a conductive member provided separately from the extraction electrode.

In such a piezoelectric transformer, the second
The shortest distance between the electrode and the extraction electrode can be a distance at which dielectric breakdown does not occur at the driving voltage of the piezoelectric transformer. Further, as the conductive member, any one of a metal plate, a metal wire, a conductive tape, and a conductive rubber is preferably used.
When a metal plate or a metal wire is used as the conductive member, the reliability is further improved by fixing the metal plate or the metal wire to the first electrode and the lead electrode by soldering or the like.

In such a piezoelectric transformer, when a metal member is used as the conductive member, the extraction electrode is not necessarily required. That is, according to the present invention, there is provided a piezoelectric transformer having a pair of input electrodes formed at predetermined positions on the front and back main surfaces of a piezoelectric ceramic, wherein the input electrodes are formed on a surface of the piezoelectric ceramic. A first electrode, a metal member connected to the first electrode and drawn out to the back surface of the piezoelectric ceramic, and a second electrode formed on the back surface of the piezoelectric ceramic so as not to conduct with the metal member. And a piezoelectric transformer characterized by the following.

Further, according to the present invention, there is provided a method for manufacturing a piezoelectric transformer, wherein a first electrode is provided at a predetermined position on a front surface of a piezoelectric ceramic, and a second electrode and a second electrode are provided at a predetermined position on a back surface of the piezoelectric ceramic. A first step of forming a third electrode at a predetermined position on a side surface of the piezoelectric ceramic by electrically connecting a lead electrode that is electrically insulated between the first electrode, the second electrode, and the third electrode. Second to perform polarization processing
A piezoelectric step, comprising: a third step of performing a polarization process between the first electrode and the second electrode; and a fourth step of electrically connecting the extraction electrode and the first electrode. A method for manufacturing a transformer is provided.

According to such a piezoelectric transformer and the method of manufacturing the same, when performing the polarization processing in the driving section, the first electrode, which is one of the input electrodes, and the extraction electrode are not electrically connected during the polarization. The distance between the first electrode and the second electrode can be reduced to a degree that does not cause dielectric breakdown when the piezoelectric transformer is driven. As a result, the area of the second electrode can be increased to increase the effective area of the input electrode, and a high boosting ratio can be obtained. Further, since the area of the extraction electrode can be minimized, the volume of the unpolarized portion where the extraction electrode and the first electrode face each other can be reduced, and the efficiency can be increased. Furthermore, since conduction between the extraction electrode and the first electrode is reliably performed by a conduction member such as a metal, it is possible to prevent a decrease in yield due to poor conduction and to increase productivity.

There is no distinction between the front and back main surfaces of the piezoelectric ceramic. That is, when the first electrode is formed on the front surface, the second electrode is formed on the back surface, and the extraction electrode is formed on the back surface as necessary. On the other hand, when the first electrode is formed on the back surface, the second electrode can be formed on the front surface, and if necessary, the extraction electrode can be formed on the front surface. Thus, in the present invention, one of the main surfaces of the piezoelectric ceramic is the front surface, and the other is the back surface.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to an example of a piezoelectric transformer driven in a λ mode using a rectangular plate-shaped piezoelectric ceramic. FIG. 1 is a plan view (a) showing an embodiment of the piezoelectric transformer of the present invention,
It is sectional drawing (b) in line AA in plan view (a), and sectional drawing (c) in line BB in plan view (a).

The piezoelectric transformer 10 includes a piezoelectric ceramic 1
The power generation part 12a is formed on one half of one side in the longitudinal direction of the power generation part 1 and the output electrode 13c is provided on the longitudinal end face of the power generation part 12a.
Are formed. The other half of the other side in the longitudinal direction of the piezoelectric ceramics 11 is a driving unit 12b,
When one of the main surfaces of the piezoelectric ceramics in the driving section 12b is defined as “front surface” and the other is defined as “back surface”, the first electrode 13a which is one of the input electrodes is formed on the front surface, and the other of the input electrodes is formed on the back surface. A certain second electrode 13b is formed, and on the back surface, an extraction electrode 14 that is provided electrically insulated (separated) from the second electrode 13b is further formed. The extraction electrode 14 and the first electrode 13a are electrically connected by a conductive member 15 having a substantially U-shaped cross section.

In the power generation section 12a, the piezoelectric ceramic 11 is polarized in the longitudinal direction, while the driving section 12b
In the example, the portion where the first electrode 13a and the second electrode 13b face each other is polarized in the thickness direction of the piezoelectric ceramic 11, and the other portions, that is, the gap 16 between the extraction electrode 14 and the second electrode 13b and Lead electrode 14
The portion where the first electrode 13a and the first electrode 13a face each other is an unpolarized portion.

FIG. 2 is an explanatory view showing a manufacturing process of such a piezoelectric transformer 10. Hereinafter, the structure of the piezoelectric transformer 10 will be described in detail by describing a method of manufacturing the piezoelectric transformer 10.

The first step is a step of forming predetermined electrodes on the prepared piezoelectric ceramics 11. Here, the piezoelectric ceramics 11 is manufactured using various known methods. For example, a piezoelectric ceramic powder having a predetermined composition is formed into a predetermined shape using a press molding method or the like, and fired under predetermined firing conditions, and then sliced as necessary.
It is manufactured by performing processing such as grinding and polishing. When the thickness of the piezoelectric ceramics 11 is small, for example, a green sheet is formed by using a sheet forming method such as an extrusion forming method, and the green sheet is cut into a predetermined shape, cut, cut out, etc., and fired. Can also be used.

The formation of electrodes on the obtained piezoelectric ceramics 11 is suitably performed by using a screen printing method. Although there is no limitation on the electrode paste used for printing, silver (Ag) paste is preferably used. Using a screen printing method, the first electrode 13a, the second electrode 13b, the extraction electrode 14, and the output electrode 13c are sequentially printed and fired simultaneously,
The electrodes are baked on the piezoelectric ceramic 11 and thus these electrodes are simultaneously formed.

Here, when the piezoelectric transformer 10 is driven in the λ mode, since the node point appears substantially at the center of the drive section 12b in the longitudinal direction, the extraction electrode 1
Reference numeral 4 is formed at a substantially central position in the longitudinal direction of the drive unit 12b. The conducting member 15 is connected to the extraction electrode 14 in a later manufacturing process.
4 is formed at a substantially central position in the longitudinal direction of the drive unit 12b, so that when the piezoelectric transformer 10 is driven,
The connection portion between the extraction electrode 14 and the conduction member 15 is prevented from being damaged such as coming off due to mechanical vibration of the piezoelectric transformer 10. Such an effect is obtained by the first electrode 13a.
Similarly, the connection between the and the conducting member 15 can be obtained.

The second electrode 13b and the lead electrode 14
Is the gap 1 depending on the pattern formed on the screen.
6 can be formed simultaneously while being separated from each other. For example, after the second electrode 13b is formed by printing and baking the entire back surface of the driving unit 12b, the YA is formed.
The extraction electrode 14 can also be formed by trimming the second electrode 13b using a G fourth harmonic laser or the like to form the gap 16. When the screen printing method is used, the width of the gap 16 is, for example, practically limited to several tens of microns, but the gap 16 is formed at a smaller interval by using laser processing. It is possible.

Next, in the second step, the first electrode 13a
Then, a polarization process in the power generation unit 12a is performed between the second electrode 13b and the output electrode 13c. That is, the first electrode 13
a and the second electrode 13b have the same potential, and the first electrode 13a
A predetermined voltage is applied between the second electrode 13b and the output electrode 13c using an external power supply to perform polarization.

Subsequently, in a third step, the first electrode 13
The polarization process in the drive unit 12b is performed between the first electrode 13a and the second electrode 13b. In a conventional piezoelectric transformer, for example, the piezoelectric transformer 90 shown in FIG. 6, since the input electrode 97a and the lead electrode 98b are electrically connected, the input electrode 97b
There is a problem that the distance between these electrodes and the lead-out electrode 98b must be sufficiently long so that dielectric breakdown does not occur.
Since the electrode 13a and the extraction electrode 14 are not electrically connected, it is possible to perform a polarization process at a predetermined voltage according to the material characteristics of the piezoelectric ceramics 11, and in the third step, the width of the gap 16 is reduced by the width of the driving unit 12b. Has no effect on the polarization conditions.

The fourth step is a step in which the first electrode 13a and the extraction electrode 14 are electrically connected by using the conductive member 15. As the conductive member 15, specifically, a metal plate, a metal wire, a conductive tape, a conductive rubber, a conductive adhesive, or the like is preferably used. In particular, a metal plate or a metal wire having high conductivity is used. Is preferred.

In the above-described fourth step, a method of forming a conductive lead in place of the conductive member 15 by screen-printing a metal paste on the side surface of the piezoelectric ceramic 11 after the polarization treatment of the driving section 12b and firing the same is performed. Cannot be used. This is because the firing temperature of the metal paste is generally higher than the Curie point of the piezoelectric ceramic 11, so that the polarization is released when the metal paste is fired, and eventually becomes the same as the piezoelectric transformer 90 shown in FIG. It is because. That is, in the piezoelectric transformer of the present invention, the conductive member 15 needs to be separate from the first electrode 13a and the extraction electrode 14.

In other words, even if the conductive member 15 does not have a predetermined shape such as a metal plate or a conductive tape, the polarization formed on the piezoelectric ceramics 11 is not or cannot be easily dissolved. Instead of using the conductive member 15, for example, using a method such as a sputtering method, the conductive member 1
It is also possible to form an electrode lead instead of 5.

In the piezoelectric transformer 10, the conductive member 1
5 is a metal plate having a substantially U-shaped cross section.
1, the first electrode 13a and the extraction electrode 1
4 is conducted. As described above, when a metal plate or a metal wire is used, for example, it is possible to provide the metal member with a spring property and hold the piezoelectric ceramics 11 in a fitted state. Irrespective of the presence or absence of, for example, by connecting the connection portion between the extraction electrode 14 and the metal member or the connection portion between the first electrode 13a and the metal member by soldering or the like, the conductive member 15 is prevented from falling off, The reliability of the piezoelectric transformer 10 can be further improved.

As described above, when the first electrode 13a and the extraction electrode 14 are made conductive by using the conductive member 15,
Since the area of the extraction electrode 14 is the minimum area required for attaching the conductive member 15, the polarization voltage is not applied between the second electrode 13b and the extraction electrode 14 as described above. The width of the gap 16 can be reduced to such an extent that dielectric breakdown does not occur at a drive voltage applied to the second electrode 13b and the extraction electrode 14 for actually driving the piezoelectric transformer 10. Thus, the effective electrode area in the driving section 12b, that is, the second electrode 13
It is possible to increase the area of b, and the boost ratio is improved.

Further, since the area between the extraction electrode 14 and the gap 16 can be reduced, the volume of the unpolarized portion between the extraction electrode 14 and the gap 16 and the first electrode 13a can be reduced. It is possible to suppress the decrease in efficiency due to the non-polarized portion not vibrating, and to increase the efficiency as compared with the conventional piezoelectric transformer 90. In addition, since the connection between the extraction electrode 14 and the first electrode 13a is reliably performed by the conductive member 15 such as a metal, it is compared with the case where the electrode leads 98a are formed by screen printing as in the conventional piezoelectric transformer 90. hand,
It is possible to prevent a decrease in yield due to conduction failure and increase productivity.

The piezoelectric transformer 1 manufactured as described above
Reference numeral 0 denotes a lead wire attached to the second electrode 13b and the lead electrode 14 on the back side of the piezoelectric ceramic 11, for example, these lead wires are respectively connected to terminals provided in the case. The attachment of such a lead wire is usually performed by soldering. However, when connecting the lead wire to the extraction electrode 14, the solder may be applied only to the extraction electrode 14,
It may be applied to both the extraction electrode 14 and the conductive member 15 or may be applied to only the conductive member 15.

Incidentally, in the piezoelectric transformer 10, the extraction electrode 14 is not always necessary if the conductive member 15 is a metal plate or a metal wire and can maintain a constant shape. That is, when the conductive member 15 is a metal member that can maintain a predetermined shape, such as the piezoelectric transformer 20 shown in the perspective view of FIG. 3, the conductive member 15 is routed to the back side of the piezoelectric ceramic 11 in the conductive member 15. It becomes possible to directly solder the lead wire 21a to the part thus cut. Note that reference numeral 21b in FIG. 3 indicates a lead wire attached to the second electrode 13b.

Next, the characteristics of the piezoelectric transformer of the present invention will be described. FIG. 4 is a schematic explanatory view showing the form of the two types of piezoelectric transformers produced. A piezoelectric transformer 10a (example) in FIG. 4A is the same as the piezoelectric transformer 10 according to the present invention shown in FIG. And has predetermined dimensions in the figure. On the other hand, the piezoelectric transformer 90a shown in FIG.
(Comparative example) has the same form as the conventional piezoelectric transformer 90 shown in FIG. 6, and has a predetermined dimension in the figure.

The piezoelectric ceramic used for the piezoelectric transformer 10a and the piezoelectric transformer 90a has a total length of 48 m.
It has a rectangular parallelepiped shape of m, width 7 mm, and thickness 2 mm, and is manufactured under the same conditions. It has been previously confirmed that the difference in the material characteristics of the piezoelectric ceramic itself is within a measurement error range. The extraction electrode 14 of the piezoelectric transformer 10a and the extraction electrode 98b of the piezoelectric transformer 90a are set to have the same area, and the influence of the extraction electrode is eliminated. The polarization conditions of the drive unit and the power generation unit are the same for the piezoelectric transformer 10a and the piezoelectric transformer 90a.

In the piezoelectric transformer 10a, the first electrode 13a, the second electrode 13b, the lead electrode 14, and the output electrode 13c are formed on the piezoelectric ceramics by screen printing based on the manufacturing process shown in FIG. After the formation, first, the power generation unit was polarized, then the drive unit was polarized, and then the extraction electrode 14 and the first electrode 13a were fabricated by attaching a metal plate having a substantially U-shaped cross section by the conducting member 15. Things.

On the other hand, the piezoelectric transformer 90a is composed of piezoelectric ceramics having input electrodes 97a and 97b and lead electrodes 98.
b, the output electrode 96 and the electrode lead 98a are formed by using a screen printing method, and then the power generation unit is polarized, and then the drive unit is polarized.

The piezoelectric transformer 10a and the piezoelectric transformer 90a
FIGS. 5A and 5B are explanatory diagrams comparing the characteristics of FIG.
FIG. 5A shows the relationship between the driving frequency and the efficiency, and FIG.
Shows the relationship between the drive frequency and the boost ratio, respectively. As shown in FIGS. 5A and 5B, it can be seen that the efficiency and the step-up ratio are high in the piezoelectric transformer 10a.

In the piezoelectric transformer 90a, since the extraction electrode 98b is connected to the input electrode 97a (not shown in FIG. 4B) when the driving section is polarized,
4A and 4B, the width of the gap 95 is set to be wider than the width of the gap 16 in order to prevent dielectric breakdown during polarization of the driving unit. That is, as compared with the piezoelectric transformer 90a, the piezoelectric transformer 10a has a higher step-up ratio due to the larger effective electrode area in the driving section, and has higher efficiency due to the smaller volume of the non-polarized section. It is thought that there is.

Further, in the piezoelectric transformer 90a,
In the portion where the gap 95 is formed, polarization in a direction substantially perpendicular to the thickness direction of the piezoelectric ceramic occurs between the input electrode 97b and the extraction electrode 98b during polarization of the driving unit, and such polarization is caused by the piezoelectric ceramic. It is also assumed that it interferes with normal vibration. The piezoelectric transformer 1
0a and the temperature rise when the piezoelectric transformer 90a is driven at a predetermined frequency is small in the piezoelectric transformer 10a.
On the contrary, it suggested that the loss generated as heat was small due to the high efficiency.

Although the piezoelectric transformer of the present invention and the method of manufacturing the same have been described above, the present invention is not limited to the above embodiment. Although a piezoelectric ceramic is preferably used for the piezoelectric transformer, the structure and manufacturing method of the piezoelectric transformer of the present invention can be applied to, for example, other piezoelectric bodies, for example, a piezoelectric transformer using a piezoelectric polymer. Needless to say, by reducing the width of the gap between the extraction electrode and the second electrode to be formed, the effective electrode area of the drive unit can be increased, and the boost ratio and efficiency are improved. Can be done.

[0042]

As described above, according to the piezoelectric transformer and the method of manufacturing the same of the present invention, when performing the polarization processing in the drive section, the first electrode, which is one of the input electrodes, and the extraction electrode are electrically connected during polarization. Therefore, the distance between the extraction electrode and the second electrode can be reduced to the extent that the dielectric breakdown does not occur when the piezoelectric transformer is driven. As a result, it is possible to increase the effective area of the input electrode, that is, the area of the second electrode, and it is possible to obtain a high boosting ratio. Also, since the area of the extraction electrode can be kept to the minimum size necessary for the connection of the conductive member, the volume of the unpolarized portion where the extraction electrode and the first electrode face each other is reduced, The effect that the efficiency can be improved is also obtained. Conversely, this also means that a piezoelectric transformer having the same step-up ratio, efficiency, and output voltage as a conventional piezoelectric transformer can be obtained in a smaller size. That is, the piezoelectric transformer of the present invention contributes to downsizing of the piezoelectric transformer, and further downsizing of the case for housing the piezoelectric transformer. Furthermore, since conduction between the extraction electrode and the first electrode is reliably performed by a conduction member such as a metal, it is possible to prevent a decrease in yield due to poor conduction and increase productivity.

[0043]

[Brief description of the drawings]

FIG. 1 is a plan view and a cross-sectional view illustrating an embodiment of a piezoelectric transformer according to the present invention.

FIG. 2 is an explanatory view showing one embodiment of a method for manufacturing a piezoelectric transformer according to the present invention.

FIG. 3 is a perspective view showing another embodiment of the piezoelectric transformer of the present invention.

FIG. 4 is an explanatory diagram comparing electrode configurations of a piezoelectric transformer according to the present invention and a conventional piezoelectric transformer.

FIG. 5 is an explanatory diagram comparing characteristics of a piezoelectric transformer according to the present invention and a conventional piezoelectric transformer.

FIG. 6 is a perspective view showing an embodiment of a conventional piezoelectric transformer.

[Explanation of symbols]

 Reference Signs List 10: piezoelectric transformer 10a; piezoelectric transformer 11; piezoelectric ceramics 12a; power generation unit 12b; drive unit 13a; first electrode 13b; second electrode 13c; output electrode 14; 21a; lead wire 21b; lead wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazumasa Asumi 2-4-2, Daisaku, Sakura City, Chiba Prefecture Inside Pacific Cement Co., Ltd. (72) Inventor Masayuki Watanabe 2-4-2, Daisaku, Sakura City, Chiba Prefecture Within Taiheiyo Cement Co., Ltd. (72) Inventor Junko Seki 2-4-2, Daisaku, Sakura City, Chiba Prefecture Within Taiheiyo Cement Co., Ltd. (72) Inventor Norifumi Iwaki 7-5 Harajuku, Hidaka City, Saitama Prefecture Megacera Co., Ltd.

Claims (5)

[Claims] 1. A piezoelectric transformer in which a pair of input electrodes is formed at predetermined positions on front and back main surfaces of a piezoelectric ceramic, wherein the input electrode is a first electrode formed on a surface of the piezoelectric ceramic. A second electrode formed on the back surface of the piezoelectric ceramic; a lead electrode provided on the back surface of the piezoelectric ceramic so as to be electrically insulated from the second electrode; and the first electrode and the lead electrode. And the first
And a conducting member provided separately from the electrode and the extraction electrode. 2. The piezoelectric transformer according to claim 1, wherein the shortest distance between the second electrode and the extraction electrode is a distance at which dielectric breakdown does not occur at a driving voltage of the piezoelectric transformer. 3. The piezoelectric transformer according to claim 1, wherein the conductive member is one of a metal plate, a metal wire, a conductive tape, and a conductive rubber. 4. A piezoelectric transformer in which a pair of input electrodes is formed at predetermined positions on front and back main surfaces of a piezoelectric ceramic, wherein the input electrode is a first electrode formed on a surface of the piezoelectric ceramic. And a metal member connected to the first electrode and drawn out to the back surface of the piezoelectric ceramic; and a second electrode formed on the back surface of the piezoelectric ceramic so as not to conduct with the metal member. Characteristic piezoelectric transformer. 5. A method of manufacturing a piezoelectric transformer, comprising: a first electrode at a predetermined position on a front surface of a piezoelectric ceramic; and a second electrode and the second electrode at a predetermined position on a back surface of the piezoelectric ceramic. A first step of forming a third electrode at a predetermined position on a side surface of the piezoelectric ceramic; and a second step of performing a polarization process between the first electrode and the second electrode and the third electrode. And a fourth step of conducting a polarization process between the first electrode and the second electrode; and a fourth step of conducting the lead electrode and the first electrode. Transformer manufacturing method.