JP3450689B2 - Piezoelectric transformer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric ceramic transformer capable of operating in a high frequency band, and more particularly to a piezoelectric ceramic transformer for an on-board switching power supply which is required to be small and thin.

[0002]

2. Description of the Related Art In recent years, there has been a demand for miniaturization of electronic equipment, and accordingly, there has been a demand for miniaturization of power supply devices. In order to reduce the size of the power supply device, for example, in the case of a switching power supply device, the switching frequency can be increased. In the switching power supply device, by increasing the switching frequency, it is possible to downsize the transformer, the coil, the capacitor, etc. that make up the switching power supply device, and thus it is possible to downsize the entire power supply device. Become.

Conventionally, an electromagnetic transformer has been used in a switching power supply device. However, when the switching frequency is increased, the hysteresis loss of the magnetic material used for the electromagnetic transformer, the eddy current loss, the loss due to the skin effect of the winding, and the like are rapidly increased, and the efficiency of the transformer is significantly reduced. Therefore, the upper limit of the practical switching frequency band of the switching power supply device using the electromagnetic transformer is about 500 KHz.

On the other hand, in recent years, attention has been paid to a piezoelectric ceramic transformer capable of performing a switching operation in a high frequency band. The piezoelectric ceramic transformer is used in a resonance state, and compared with a general electromagnetic transformer, (1) the efficiency of the transformer is high in a high frequency band of 500 KHz or higher, (2) noncombustible, (3) electromagnetic induction It has the advantage that no noise is generated due to.

As such a piezoelectric ceramic transformer, the inventor of the present application has proposed, for example, a thickness-shear vibration type piezoelectric ceramic transformer (Japanese Patent Application No. 9-31).
9330). In FIG. 6, the piezoelectric ceramic plate 1 is polarized perpendicularly to the plate thickness direction as indicated by an arrow 17 in the figure. On the top surface of the piezoelectric ceramic plate 1, six electrodes 11 to 16 are arranged side by side. Further, on the lower surface of the piezoelectric ceramic plate 1, six electrodes 21 to 21 are provided at positions facing the input electrodes on the upper surface.
26 are installed side by side.

FIG. 7 shows an example in which lead terminals are attached to the thickness-shear vibration type piezoelectric ceramic transformer shown in FIG.
Here, an example is given in which three input electrode pairs and three output electrode pairs are connected in parallel and the input / output impedance is set to 1: 1. The electrodes 11, 13 and 15 are connected to the input terminal 301, and the electrodes 21, 23 and 2 are
5 is connected to the other input terminal 302. The electrodes 12, 14 and 16 are connected to the output terminal 303, and the electrodes 22, 24 and 26 are connected to the other output terminal 304.

The operating principle of this thickness-shear vibration type piezoelectric ceramic transformer is shown in FIG. Input terminals 301 and 30 of FIG.
When applying an AC voltage of a frequency of the resonant frequency near the thickness shear vibration mode of the piezoelectric ceramic plate 1 between two thickness with an electromechanical coupling factor k ₁₅ in the region A1, A3, A5 of the piezoelectric ceramic plate 1 in FIG. 6 The slip vibration (15) mode causes a displacement in the piezoelectric ceramic plate 1 to excite thickness shear vibration, and this vibration excites the entire transformer.

At this time, in the areas A2, A4 and A6 which are output parts of the piezoelectric ceramic plate 1 of FIG. 6, an AC voltage is generated in the thickness shear vibration (15) mode with an electromechanical coupling coefficient k _15, and as a result, The AC voltage can be taken out between the seven output terminals 303 and 304.

[0009]

By the way, a thickness-shear vibration type piezoelectric ceramic transformer as shown in FIGS.
At the time when the AC voltage -V at point A in (A) is applied, stresses F1 and F2 in the thickness shear vibration (15) mode occur,
As shown in FIG. 8B, displacement occurs such that the positions of the upper and lower surfaces of the piezoelectric ceramic plate are displaced. At the time when the AC voltage at the point B is 0 V, the stress disappears as shown in FIG. 8C, and the displacement of the upper and lower surfaces also disappears. At the time when the AC voltage + V at the point C is applied, stresses F3 and F4 occur, and the upper and lower surfaces of the piezoelectric ceramic plate are displaced in the opposite direction to that of FIG. 8A, as shown in FIG. 8D. .

For this reason, when a thickness-shear vibration pressure type electromagnetic transformer is mounted on a device, if it is supported so as to sandwich the upper and lower surfaces, the displacement caused by the thickness-shear vibration will be hindered, and the vibration will be significantly attenuated. Therefore, there is a problem that the power conversion efficiency of the piezoelectric ceramic transformer is significantly reduced. Further, in the thickness-shear vibration piezoelectric ceramic transformer, it is necessary to reduce the impedance when handling a large current, and for this purpose it is necessary to increase the area of the input / output electrodes. There is a problem that the area of the transformer becomes large and the size becomes large.

An object of the present invention is to reduce the loss of vibration generated in the transformer even when the upper and lower surfaces of the transformer are supported, and to reduce the area of the transformer even when handling a large current. Provide a transformer.

[0012]

In order to achieve this object, the laminated thickness-shear vibration type piezoelectric ceramic transformer according to the present invention is uniformly polarized in the direction perpendicular to the thickness direction of the electrode layer and the plate. It has a laminated body in which a plurality of piezoelectric ceramic plate layers are alternately laminated, and each of the electrode layers is arranged so as to face both surfaces in the thickness direction of the piezoelectric ceramic plate layer, and is close to the resonance frequency of the thickness shear vibration mode. The input electrode pair which excites the piezoelectric ceramic plate layer by applying the AC voltage of the piezoelectric ceramic plate and the input electrode pair facing the both surfaces in the thickness direction of the piezoelectric ceramic plate and arranged side by side with the pair of input electrodes. It is characterized in that it is provided with an output electrode pair for extracting an AC voltage induced by the excitation of the layer.

Here, by laminating the ceramic plate layers of the laminated body into any even number of n layers and laminating each layer so that the displacement of the thickness shear vibration generated in the piezoelectric ceramic plate layer is in the opposite direction. A laminated structure that does not cause displacement on opposing outer surfaces (supporting surfaces) in the thickness direction of the laminated body when being excited by thickness shear vibrations by application of an AC voltage. In addition, the piezoelectric ceramic plates of the laminated body are laminated on any even number of n layers, and (n /
2) By laminating the remaining (n / 2) layers of the piezoelectric ceramic plate layers so as to cause the displacement of the thickness sliding vibration in the opposite direction with respect to the displacement of the thickness sliding vibration generated in the two piezoelectric ceramic plate layers, When the thickness shear vibration is excited by the application of an AC voltage, a laminated structure may be used in which the opposing outer surfaces (supporting surfaces) in the thickness direction of the laminated body are not displaced.

Further, as a specific example of the electrode structure of the laminated body, (n + 1) electrode layers provided with input electrodes and output electrodes are alternately arranged with respect to n piezoelectric ceramic plate layers, and (n + 1)
An input electrode pair is formed by connecting every other input layer of the electrode layer of one layer to each other and connecting to a pair of input terminals, and is connected every other layer of the output electrode of the (n + 1) layer electrode layer. Then, an output electrode pair is formed by connecting to the pair of output terminals.

According to the laminated thickness-shear vibration type piezoelectric ceramic transformer of the present invention as described above, when the transformer is mounted on a device, even if the transformer is supported so as to sandwich the upper and lower surfaces, the displacement caused by the thickness-shear vibration is generated. Is not disturbed, and therefore, the vibration is not significantly damped. That is, when the transformer is mounted on a device, the power transmission efficiency can be made higher than that of the conventional laminated thickness sliding vibration piezoelectric ceramic transformer.

Further, by using a laminated body, it is possible to secure a sufficient electrode area, reduce impedance, and handle a large current without increasing the size of the electrode with respect to the size of the transformer.

[0017]

1 is a perspective view showing an embodiment of a laminated thickness shear vibration type piezoelectric ceramic transformer according to the present invention. 1, the piezoelectric ceramic transformer of the present invention is composed of a laminated body 100 in which electrode layers 10, 20, 30, 40, 50 and piezoelectric ceramic plate layers 101, 102, 103, 104 are alternately laminated. Here, when the number of piezoelectric ceramic plate layers forming the laminated body 100 is n, the number n of layers is an arbitrary even number, and in the embodiment of FIG. 1, n = 4 layers is taken as an example. .

The electrode layers provided for any even number of n piezoelectric ceramic plate layers are (n + 1) layers, as shown in FIG.
In the above embodiment, the number of electrode layers is n + 1 = 5 layers. In this embodiment, the piezoelectric ceramic plate layers 101 to 104 are polarized in polarization directions 201, 202, 203, and 204 that are perpendicular to the plate thickness direction as indicated by arrows on the right side surface, and the same polarization direction 201. , 202, 203, 204
Are stacked so that they face each other.

The electrode layers 10 to 50 include six electrodes 11, such as the electrode layer 10 on the upper surface of the piezoelectric ceramic plate layer 101.
It is divided into 12, 13, 14, 15, and 16. In the electrode layer 20 on the lower surface of the piezoelectric ceramic plate layer 101 facing the electrode layer 10, the six electrodes 21 to 26 are arranged side by side so as to face the six electrodes 11 to 16 on the upper surface. The electrodes 21 to 26 are integrated with the six electrodes on the upper surface of the next piezoelectric ceramic plate layer 102.

Similarly, for the electrode layer 30 between the piezoelectric ceramic plate layers 102 and 103, the six electrodes 31, 32 and 3 are also provided.
3, 34, 35 and 36 are arranged side by side, and the electrode layer 40 between the next piezoelectric ceramic plate layers 103 and 104 is also the six electrodes 4
1, 42, 43, 44, 45, 46 are arranged side by side,
Further, six electrodes 51, 52, 53, 54, 55, 56 are also provided on the lower side of the piezoelectric ceramic plate layer 104 which is the lower surface of the laminated body 100.
Are arranged side by side.

Here, the case where the number of electrodes arranged in the electrode layers 10 to 50 is six is taken as an example, but the number of electrodes provided in the electrode layers can be set to an appropriate number as necessary. FIG. 2 is an explanatory diagram in which lead terminals for input and output are attached to the laminated body 100 of the piezoelectric ceramic transformer of FIG.
First, for one input terminal 301, the three electrodes 11, 13, 1 of the electrode layer 10 located on the upper surface of the laminate 100 are connected.
5 are connected in parallel. The electrodes 11, 1 of this electrode layer 10
3, 15 are connected to the electrodes 31, 33, 35, respectively, which are opposite positions in the electrode layer 30 with one space left therebetween, and the opposite positions of the electrode layer 50 located on the lower surface with another space placed. Of electrodes 51, 53, 55. The input terminal 302 is the electrode 4 in the second electrode layer 40 from the bottom.
1, 43 and 45 are connected in parallel, and the electrode layers 40 to 1
The three electrodes 21, 23, 23 of the upper electrode layer 20 spaced apart by
25 are connected to each.

The output terminal 303 is connected in parallel to the electrodes 12, 14 and 16 of the upper electrode layer 10, then to the electrodes 32, 34 and 36 of the third electrode layer 30, and further to the bottom electrode. It is connected to the electrodes 52, 54, 56 of layer 50. The output terminal 304 is the third electrode layer 40 located at the second position from the bottom.
Electrodes 22 and 2 of the upper electrode layer 20 which are connected in parallel to the two electrodes 42, 44 and 46 and are separated by one from the electrode layer 40.
4 and 26 respectively.

Input terminals 301 and 3 as shown in FIG.
02 and the output terminals 303 and 304, the respective electrode layers 10
By connecting the electrodes of ~ 50, the areas A1, A3, A in FIG.
The electrodes located in 5 are electrically connected in parallel to form an input section, and the electrodes located in the areas A2, A4 and A6 are connected in parallel to form an output section. In this case, the input section and the output section The electrode areas of are the same, and the input and output impedances are used in a one-to-one relationship.

Of course, the connection between the input section and the output section is not limited to the embodiment shown in FIG. 2. For example, by connecting the electrodes of the input section electrically in series and connecting the electrodes of the output section in parallel, It is also possible to have a high impedance part and a low impedance output part. Conversely, by connecting the electrodes of the input section electrically in parallel and connecting the electrodes of the output section electrically in series,
It is also possible to make the input part have low impedance and the output part have high impedance.

Further, in the embodiment of FIG. 2, the electrode layer 1
Although the electrodes of the input section and the output section are alternately arranged in 0 to 50, the arrangement may be interchanged or they may be grouped together in one place. Each of the piezoelectric ceramic plate layers 101 to 104 in the embodiment of FIG. 1 is manufactured using a zircon zinc titanate (PbTiO ₃ —PbZrO ₃ ) based piezoelectric ceramic material as a material. Of course, the piezoelectric ceramic material is not limited to the lead zirconate titanate-based piezoelectric ceramic material, and other materials may be used as long as the electromechanical coupling coefficient k ₁₅ of the thickness shear vibration is large.

In manufacturing the piezoelectric ceramic plate layers 101 to 104, first, the piezoelectric ceramic material powder is mixed with a binder and press-molded. Press-molded piezoelectric ceramic material powder 1 at 600 ° C
After the binder removal treatment is performed for a time (temperature rising rate 100 ° C./1 hour), firing is performed at 1200 ° C. for 2 hours. By cutting and polishing the fired piezoelectric ceramic plate layers 101 to 104,
The piezoelectric ceramic plate layers 101 to 104 are used. Here, the piezoelectric ceramic plate layers 101 to 104 are formed by press-molding piezoelectric ceramic material powder,
Although it is formed by firing, it may be formed by a method of forming a green sheet by using a doctor blade method and then firing it.

Next, the Ag paste is applied to the opposite side surfaces of the piezoelectric ceramic plate layers 101 to 104 and fired to burn the Ag electrodes. Piezoelectric ceramic plate layer 10 with Ag electrode baked
1 to 104 in insulating oil at 120 ° C. at 2.8 KV /
A voltage of mm is applied to the Ag electrode, and the piezoelectric ceramic plate layers 101 to 1
A width direction orthogonal to the thickness direction of 04, that is, a polarization direction 201.
Polarization processing is performed to uniformly polarize so as to obtain a value of up to 204.

After the polarization treatment is completed, the Ag electrode burned on the side surface in the lengthwise direction is polished and removed. A here
Although the electrodes are formed on the opposite side surfaces of the piezoelectric ceramic plate layers 101 to 104 by using the g paste, the electrodes are not limited to the Ag paste and any conductive material may be used for forming the electrodes. Then, six electrodes are formed on the upper and lower surfaces of the piezoelectric ceramic plate layers 101 to 104 by using an Au thin film by a sputtering method. Of course, the electrode is not limited to the Au thin film, and any conductive material may be used for forming the electrode.

In this way, the piezoelectric ceramic plate layers 101 to 10
4 can be formed, as shown in FIG.
204 are aligned in the same direction and stacked, and the electrode layers 20, 30, and 40 located between them are coated with solder paste or a conductive adhesive on the surface and stacked, and then fused by heating to electrically and Mechanically connected electrode layers 20, 30,
40 is formed. Finally, as shown in FIG.
The electrodes 11 to 56 are connected to the input terminals 301 and 302 and the output terminals 303 and 304.

The piezoelectric ceramic of FIG. 2 produced in this way
Between the input terminals 301 and 302 of the transformer, as shown in FIG.
The thickness of the piezoelectric ceramic plate layers 101 to 104 like the input voltage of
AC voltage with a frequency near the resonance frequency of the sliding vibration mode
Is applied, corresponding to the areas A1, A3, A5 in FIG.
The piezoelectric ceramic plate layers 101 to 104 have an electromechanical coupling coefficient k. ₁₅
Causes the thickness shear vibration to be excited.

3C, 3D and 3E show the piezoelectric ceramic transformer of the present invention when the input voltage of FIG. 3B is applied,
As shown in FIG. 3A, it is viewed from the side. First, in the piezoelectric ceramic transformer of FIG. 3A, voltages of the same polarity are applied to the piezoelectric ceramic plate layers 101 and 103, as is apparent from the connection with the lead terminals of FIG. In addition, the piezoelectric ceramic plate layers 102 and 104 include the piezoelectric ceramic plate layer 10
A voltage opposite to that of 1, 103 is applied. Here, since the polarization directions 201 to 204 of the piezoelectric ceramic plate layers 101 to 104 are all in the same direction, the displacement of the thickness shear vibration occurs in each layer in opposite directions.

That is, when the input voltage -V at the point A in FIG. 3 (B) is applied, the piezoelectric ceramic plate layer 10 as shown in FIG. 3 (C).
1,103 causes the displacement of the thickness shear vibration that tilts to the right,
On the other hand, the piezoelectric ceramic plate layers 102 and 104, on the contrary, cause the displacement of the thickness shear vibration which tilts to the left. Here, the laminated body 100
Assuming that the upper surface and the lower surface of the plate are fixed by mounting on the device, the piezoelectric ceramic plate layers 101 and 102, and the piezoelectric ceramic plate layer 1
In each of 03 and 104, the horizontal displacement of the upper and lower surfaces is canceled. Therefore, even if the upper and lower surfaces are supported, no loss occurs in the vibration generated in the transformer.

When the input voltage at the point B in FIG. 3 (B) is 0 volt, the piezoelectric ceramic plate layers 101 to 10 as shown in FIG. 3 (D).
4 returns to the initial state with no displacement. Next, when the input voltage + V is applied at the point C in FIG. 3B, the piezoelectric ceramic plate layers 101 and 103 are displaced to the left by the thickness shear vibration as shown in FIG. On the other hand, the piezoelectric ceramic plate layer 102,
On the contrary, 104 causes the displacement of the thickness shear vibration which tilts to the right.

Therefore, the displacement of the upper and lower surfaces is canceled between the piezoelectric ceramic plate layers 101 and 102 and between the piezoelectric ceramic plate layers 103 and 104. As a result, even if the upper and lower surfaces of the transformer are fixed by mounting on a device, there is no loss in the vibration generated in the transformer. Further, in the piezoelectric ceramic transformer of the present invention, the piezoelectric ceramic plate layers 101 to 10
By using the laminated body 100 in which four layers are laminated, the electrode area increases according to the number of laminated layers, and even if the mounting area of the same transformer is sufficient as compared with the single layer type piezoelectric ceramic transformer shown in FIG. It is possible to secure a large electrode area, reduce the input impedance, and easily handle a large current.

FIG. 4 shows another embodiment of the piezoelectric ceramic transformer according to the present invention. As with the embodiment of FIG. 1, a laminated body 100 using n = 4 piezoelectric ceramic plate layers 101 to 104 is taken as an example. . The piezoelectric ceramic plate layers 101 to 104 and the respective electrode layers 10 to 50 of the laminate 100 of this embodiment,
Further, the connection of the input / output terminals to each of the six electrodes forming the electrode layers 10 to 50 is the same as in FIGS. 1 and 2.

On the other hand, in the embodiment of FIG. 4, the polarization directions 201, 202, 203 and 204 which are polarized perpendicularly to the plate thickness directions of the piezoelectric ceramic plate layers 101 to 104 are different. In this embodiment, the upper two piezoelectric ceramic plate layers 101 and 102 are laminated so that the polarization directions 201 and 202 are opposite to each other, and the lower two piezoelectric ceramic plate layers 103 and 104 are also polarized direction 203. , 204, so that they are laminated in opposite directions.

That is, the upper two piezoelectric ceramic plate layers 101, 1
02, and the polarization directions 203 and 204 of the lower two piezoelectric ceramic plate layers 103 and 104.
And the combination of are laminated so as to be symmetrical in the vertical direction. If this is expressed in the general form for an arbitrary even number of n layers, the displacement of the thickness sliding vibration in the opposite direction is generated with respect to the displacement of the thickness sliding vibration generated in the (n / 2) layer piezoelectric ceramic plate layer. It can be said that the remaining (n / 2) layers of piezoelectric ceramic plate layers are laminated.

FIG. 5 shows a case where an AC voltage having a frequency near the resonance frequency of the thickness shear vibration mode is applied between the input terminals 301 and 302 to which the lead terminals are connected as shown in FIG. It shows the operation. First, FIG. 5 (B)
When such an AC voltage is applied, the thickness shear vibration is excited in the piezoelectric ceramic transformer of FIG. 4 with the electromechanical coupling coefficient k ₁₅ .

That is, by connecting the electrodes of the electrode layers 10 to 50 to the input terminals 301 and 302 of FIG. 2, voltages of the same polarity are applied to the piezoelectric ceramic plate layers 101 and 103 of FIG. Further, a voltage having the opposite polarity to the voltage applied to the piezoelectric ceramic plate layers 101 and 103 is applied to the piezoelectric ceramic plate layers 102 and 104. Here, the piezoelectric ceramic plate layers 101, 10
Since the two polarization directions 201 and 202 are opposite to each other, displacement in the same direction occurs.

Further, since the piezoelectric ceramic plate layers 103 and 104 have the polarization directions 203 and 204 opposite to each other, the displacements occur in the same direction. Further, the combination of the piezoelectric ceramic plate layers 101 and 102 and the combination of the piezoelectric ceramic plate layers 103 and 104 have a polarization direction of 2
Since 01 and 202 and the polarization directions 203 and 204 are laminated so as to be symmetrical, the displacement generated by each combination is opposite.

Specifically, FIG. 5 shows the end face of the laminated body 100 of FIG. 5A showing the polarization directions 201 to 204.
When the voltages -V, 0, and + V at points A, B, and C in (B) are applied, the displacements shown in FIGS. 5C, 5D, and 5E occur. That is, when the input voltage -V at the point A in FIG. 5 (B) is applied, the upper half of the piezoelectric ceramic plate layer 10 as shown in FIG. 5 (C).
1, 102 causes the displacement of thickness shear vibration that tilts to the right,
On the other hand, the piezoelectric ceramic plate layers 103 and 104 in the lower half, on the contrary, cause a displacement due to thickness shear vibration that tilts to the left, and the displacement of the upper and lower surfaces is canceled as a whole transformer.

When the input voltage becomes 0 volt at point B in FIG. 5B, it returns to the initial position without displacement as shown in FIG. 5C, and + V volt at point C in FIG. 5B is applied. Then, it is displaced as shown in FIG. That is, the upper half piezoelectric ceramic plate layers 101 and 102 generate a displacement due to thickness shear vibration that tilts to the left, while the lower half piezoelectric ceramic plate layers 103 and 102,
104 causes displacement of thickness shear vibration that tilts to the right, which cancels the displacement of the upper and lower surfaces of the entire transformer.

Therefore, even in the embodiment of FIG. 4, even when the upper and lower surfaces of the laminated body 100 are supported and fixed by mounting on a device, the displacement of the upper and lower surfaces due to the thickness shear vibration due to the application of the AC voltage. Are canceled out, so that the vibration generated in the transformer is not lost. Further, by stacking, the electrode area can be increased in the same transformer mounting area as compared with the transformer of FIG. 6 having a single layer structure, and for example, the input impedance can be reduced to handle a large current.

In the embodiment of FIG. 4 as well, the number of piezoelectric ceramic plate layers is not limited to four, but may be any other appropriate even number. Also, the number of electrodes provided in the electrode layer can be appropriately determined as necessary.

[0045]

As described above, according to the piezoelectric ceramic transformer of the present invention, when the transformer is mounted on a device, even if the transformer is supported and fixed so as to sandwich the upper and lower surfaces of the transformer, the thickness shear vibration occurs. It is possible to solve the problem of remarkably attenuating the transformer vibration by mounting the device without hindering the displacement, and to increase the power transmission efficiency of the transformer.

Further, by adopting the laminated structure, the electrode area provided for the piezoelectric ceramic plate layer can be increased with respect to the mounting area of the transformer to reduce the impedance of the transformer, and the laminated structure having the same mounting size can be obtained. Compared to a piezoelectric ceramic transformer that does not have it, it can realize a sufficiently small impedance with a small mounting area and handle a large current.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a piezoelectric ceramic transformer according to the present invention.

FIG. 2 is an explanatory diagram of input / output lead terminal connection in the piezoelectric ceramic transformer of FIG.

FIG. 3 is an operation explanatory view of the piezoelectric ceramic transformer of FIG.

FIG. 4 is a perspective view of another embodiment of the piezoelectric ceramic transformer according to the present invention.

5 is an operation explanatory view of the piezoelectric ceramic transformer of FIG.

FIG. 6 is a perspective view of a piezoelectric ceramic transformer proposed by the inventor of the present application.

7 is an explanatory diagram of input / output lead terminal connection in the piezoelectric ceramic transformer of FIG.

FIG. 8 is an operation explanatory view of the piezoelectric ceramic transformer of FIG.

[Explanation of symbols]

10, 20, 30, 40, 50: Electrode layers 11-16, 21-26, 31-36, 41-46, 5
1 to 56: Electrodes 100: Laminated bodies 101 to 104: Piezoelectric ceramic plate layers 201 to 204: Polarization directions 301 and 302: Input terminals 303 and 304: Output terminals

Claims (4)

(57) [Claims] 1. A laminated body, in which a plurality of electrode layers and piezoelectric ceramic plate layers uniformly polarized in a direction perpendicular to the thickness direction of the plate are alternately laminated, each of the electrode layers being composed of the piezoelectric layer. An input electrode pair, which are arranged so as to face each other in the thickness direction of the porcelain plate layer and which excites the piezoelectric ceramic plate layer by applying an AC voltage in the vicinity of the resonance frequency of the thickness shear vibration mode, and the piezoelectric ceramic plate. A pair of output electrodes facing both surfaces located in the thickness direction of the layer and arranged side by side with the input electrode pair, for extracting an AC voltage induced by the excitation of the piezoelectric ceramic plate layer by the input electrode pair; A piezoelectric ceramic transformer. 2. The piezoelectric ceramic transformer according to claim 1, wherein the laminated body is formed by laminating the piezoelectric ceramic plate layers into any even number of n layers, and generating each layer in the piezoelectric ceramic plate layer. By stacking so that the displacement of the thickness shear vibration is in the opposite direction, when the thickness shear vibration is excited by the application of the AC voltage, a laminate that does not cause displacement on the outer surfaces facing each other in the thickness direction of the laminate is formed. A piezoelectric ceramic transformer characterized by having a structure. 3. The piezoelectric ceramic transformer according to claim 1, wherein the piezoelectric ceramic plates are laminated on any even number of n layers,
The remaining (n / 2) layers of piezoelectric ceramic plate layers are laminated so that the displacement of the thickness sliding vibration occurs in the opposite direction to the displacement of the thickness sliding vibration generated in the (n / 2) layer piezoelectric ceramic plate layer. Thus, a piezoelectric ceramic transformer having a laminated structure that does not cause displacement on the outer surfaces facing each other in the thickness direction of the laminated body when the thickness shear vibration is excited by the application of the AC voltage. 4. The piezoelectric ceramic transformer according to claim 2 or 3, wherein (n + 1) electrode layers having input electrodes and output electrodes are alternately arranged with respect to the n piezoelectric ceramic plate layers. The input electrodes of the (n + 1) th electrode layer are commonly connected to every other layer and connected to a pair of input terminals to form the input electrode pair, and one of the output electrodes of the (n + 1) th electrode layer is formed. A piezoelectric ceramic transformer, characterized in that the output electrode pairs are formed by commonly connecting layers to each other and connecting to a pair of output terminals.