JP5318337B2 - Piezoelectric transformer and mounting method thereof - Google Patents

Description

  The present invention relates to a piezoelectric transformer used for a high voltage power source such as a cold cathode tube used in a backlight of a liquid crystal display, a copying machine, a laser printer, an air cleaner, and a mounting method thereof.

  As a prior art related to this type of piezoelectric transformer, one having a structure in which a plate-like piezoelectric body is accommodated in a resin case and mounted on a circuit board using a pin terminal protruding from the resin case is known ( For example, see Patent Document 1.) In this prior art, a piezoelectric body (piezoelectric transformer main body) is accommodated vertically in a box-shaped case that opens to the bottom surface side, and the case is accompanied by three pin terminals that extend to the bottom surface side. The pin terminal is structured to be connected to the primary electrode and the secondary electrode of the piezoelectric body via a gold thread wire, respectively.

According to the prior art piezoelectric transformer, the piezoelectric body can be accommodated in the case so that the parts can be handled in the packaged state, and the pin terminal protruding from the case is inserted into the through hole of the circuit board for mounting. can do.
JP 2006-108332 A

  Since the piezoelectric transformer performs transformation by utilizing mechanical vibration of the piezoelectric body, several places of the piezoelectric body cannot be fixed to the substrate at the same time. In this regard, if the structure is such that the pin terminal, the primary electrode, and the secondary electrode are connected by a gold thread wire with the piezoelectric body (piezoelectric transformer main body) housed in the case as in the prior art, the piezoelectric body remains housed in the case Can be mounted on a circuit board. For this reason, the prior art has an advantage that it is excellent in handling of components and mounting workability on a circuit board, and can be said to be one preferable example as a structure and mounting method of a piezoelectric transformer.

  On the other hand, the piezoelectric transformer is required to improve the mounting workability and reduce the mounting height and mounting volume. However, it is technically difficult to directly fix the piezoelectric body to the circuit board as described above (it is broken if it is fixed at a plurality of locations, or the voltage conversion efficiency deteriorates), and it is simply the prior art. The idea of reducing the mounting height by omitting the case is still not feasible.

  Accordingly, an object of the present invention is to provide a piezoelectric transformer and a mounting method thereof that can reduce the mounting height and mounting volume without damaging the piezoelectric body.

  The present invention relates to a piezoelectric body in which a primary electrode for inputting a voltage and a secondary electrode for outputting a transformed voltage are respectively formed on the outer surface, corresponding to the positions of the primary electrode and the secondary electrode, respectively. Inserted while being sandwiched between two sets of holding members installed on the circuit board, and at the time of this insertion, a state in which an elastic body having conductivity is interposed between at least the secondary electrode and the holding member By mounting it on the circuit board, the periodic voltage is input to the piezoelectric body through the primary electrode, while the mechanical vibration of the piezoelectric body generated by the input of this voltage is converted into a voltage to convert the voltage from the secondary electrode. This is a mounting method configured as a piezoelectric transformer for output.

In order to realize the above mounting method, the piezoelectric transformer of the present invention has the following structure. That is, in the piezoelectric body having a flat plate shape, primary electrodes are respectively formed on two outer surfaces that make a pair in the thickness direction along the side having the shortest one side among the sides constituting the piezoelectric body. The primary electrode serves as an input electrode for generating mechanical vibrations by inputting a periodic voltage to the piezoelectric body through the primary electrode. Apart from such a primary electrode, a secondary electrode is formed on the outer surface of the piezoelectric body. The secondary electrode is for converting the vibration generated by the input of the voltage from the primary electrode into a voltage and outputting the voltage. Further, the secondary electrode may be formed on the outer surface located at the end when the piezoelectric body has a longitudinal direction in addition to the thickness direction.

An input circuit connected to the primary electrode and an output circuit connected to the secondary electrode are formed on the circuit board to which the piezoelectric body is attached, and a holding member is provided on the mounting surface of the circuit board. Holding member holds the piezoelectric body sandwiched state in the thickness direction at portions corresponding to the primary electrodes and the secondary electrodes even without low, and each output circuit and input circuit of the primary electrodes and the secondary electrodes in this holding state Connect. At this time, an elastic body having conductivity is provided at least between the holding member and the secondary electrode in a state where the piezoelectric body is held by the holding member. The elastic body is electrically connected between the holding member and the secondary electrode.

  According to the piezoelectric transformer and the mounting method of the present invention, since the elastic body is interposed between the secondary electrode and the holding member that holds the piezoelectric body at least at a position corresponding to the secondary electrode, Vibration is not disturbed. And since an elastic body has electroconductivity, the voltage output from a secondary electrode can be reliably taken out through a holding member. In addition, since the vibration of the piezoelectric body is absorbed by the elastic body, the piezoelectric body and the holding member are not mechanically damaged.

  Further, in the present invention, even when the piezoelectric body is not exposed to a case or the like and is attached to the circuit board without being exposed, the vibration is not inhibited and there is no fear of destruction. Therefore, the mounting height and mounting volume as a piezoelectric transformer can be significantly reduced, and the manufacturing cost can be reduced by reducing the number of components.

  Furthermore, the electrical connection between the holding member and the primary and secondary electrodes is simple crimping. This eliminates the need for soldering when mounting the piezoelectric transformer, thereby reducing the manufacturing cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a perspective view showing the piezoelectric transformer of the first embodiment. The piezoelectric transformer includes a piezoelectric ceramic 2. The piezoelectric ceramic 2 is obtained by polarizing a piezoelectric body such as lead zirconate titanate ceramic (PZT). Although the shape of the piezoelectric ceramic 2 is not particularly limited, a rectangular parallelepiped shape (flat plate shape) can be given as an example here.

  In FIG. 1, the dimension (length) in the longitudinal direction of the piezoelectric ceramic 2 is defined as L, the dimension (width) in the width direction is defined as W, and the dimension (thickness) in the thickness direction is defined as T. At this time, primary electrodes 4 are respectively formed on both surfaces (only one surface is shown in FIG. 1) of the outer surface of the piezoelectric ceramic 2 that is paired in the thickness direction. Although only one side is shown in FIG. 1, the same primary electrode 4 is also formed on the opposite side.

  On the outer surface of the piezoelectric ceramic 2, a secondary electrode 6 is formed on the other end in the longitudinal direction on one surface (one surface shown in the figure) that is paired in the thickness direction. The primary electrode 4 and the secondary electrode 6 are formed on the outer surface of the piezoelectric ceramic 2 by, for example, screen printing using a metal paste.

  The piezoelectric transformer is configured with the piezoelectric ceramic 2 mounted on the circuit board 8. On the mounting surface of the circuit board 8, a wiring pattern (not shown) is formed, and two sets of holding members 10 and 12 connected to the wiring pattern are provided. These holding members 10 and 12 are formed by bending a metal plate, for example. The individual holding members 10, 12 have base end portions 10 a, 12 a bonded to the wiring pattern on the mounting surface of the circuit board 8, and the portions beyond the base end portions 10 a, 12 a are from the mounting surface of the circuit board 8. Extends away. As shown in FIG. 1, when the circuit board 8 is arranged at a lower position, the holding members 10 and 12 are in a state of extending so as to rise upward from the mounting surface of the circuit board 8.

  Each set of holding members 10 and 12 is configured with two metal plates facing each other. In this state, the holding members 10 and 12 can cause the portions ahead of the base end portions 10a and 12a to act as leaf springs, respectively. That is, each set of the holding members 10 and 12 sandwiches the piezoelectric ceramic 2 in the thickness direction, and holds the piezoelectric ceramic 2 by its action as a leaf spring. In this state, the lower end surface of the piezoelectric ceramic 2 is not in contact with the mounting surface of the circuit board 8, and an appropriate clearance is secured between them.

  FIG. 2 is a horizontal sectional view of the piezoelectric transformer taken along line II-II in FIG. The holding members 10 and 12 are terminals (crimp terminals) that respectively connect the primary electrode 4 and the secondary electrode 6 to the corresponding wiring patterns by sandwiching the piezoelectric ceramic 2 at portions corresponding to the primary electrode 4 and the secondary electrode 6, respectively. ). However, since the piezoelectric ceramic 2 expands and contracts in the longitudinal direction, conductive rubbers 14 and 16 are provided between the holding members 10 and 12 and the primary electrode 4 and the secondary electrode 6, respectively. These conductive rubbers 14 and 16 maintain the electrical connection relationship between the holding members 10 and 12 and the primary electrode 4 and the secondary electrode 6, and also serve to absorb displacement caused by vibration of the piezoelectric ceramic 2. Bear. That is, even if the primary electrode 4 and the secondary electrode 6 are displaced with respect to the holding members 10 and 12 due to the stretching vibration of the piezoelectric ceramic 2, the displacement is caused by elastic deformation of the conductive rubbers 14 and 16 (in this case, shearing). Therefore, the holding members 10 and 12 do not rub against the primary electrode 4 and the secondary electrode 6. For the conductive rubbers 14 and 16, a known conductive rubber material can be used.

  Here, the position where the holding member 10 holds the primary electrode 4 is set, for example, at a position separated from the one end by a quarter length (L / 4) when viewed in the longitudinal direction of the piezoelectric ceramic 2. This position corresponds to a node point (node) in the vibration of the piezoelectric ceramic 2. Although the conductive rubber 14 is interposed in the example of FIGS. 1 and 2, in the first embodiment, the amplitude of the piezoelectric ceramic 2 is considered to be zero at the position corresponding to the holding member 10. Is not essential, and the conductive rubber 14 may not be interposed between the holding member 10 and the primary electrode 4.

  FIG. 3 is a circuit diagram schematically showing the electrical configuration of the piezoelectric transformer. Although not shown in FIG. 1, an input voltage generator 18, an input circuit 20, and an output circuit 22 are formed on the circuit board 8. Among these, the input circuit 20 is connected to the primary electrode 4 of the piezoelectric ceramic 2 via the holding member 10 and the conductive rubber 14. The output circuit 22 is connected to the secondary electrode 6 of the piezoelectric ceramic 2 via the holding member 12 and the conductive rubber 16. Both the input circuit 20 and the output circuit 22 can be formed on the circuit board 8 as a wiring pattern.

  The piezoelectric transformer applies an input voltage at the resonance frequency (the natural frequency depending on the length L) of the piezoelectric ceramic 2 by the input voltage generator 18, and mechanical vibration (stretching vibration) in the longitudinal direction is applied to the piezoelectric ceramic 2. Give rise to The piezoelectric transformer can take out the electric charge obtained by the piezoelectric effect from the secondary electrode 6 through the output circuit 22 and use it as a transformed output voltage. Such a piezoelectric transformer is suitable for applications such as a laser printer, a high-voltage power supply unit, a transformer for a backlight (cold cathode tube) inverter of a liquid crystal display, but is not limited thereto.

  The above is the configuration of the piezoelectric transformer of the first embodiment. In such a piezoelectric transformer, the plate-like piezoelectric ceramics 2 each having the primary electrode 4 and the secondary electrode 6 formed on the outer surface thereof are divided into the dimensions (length L, width W, thickness T) and the primary electrodes 4 and 2. The secondary electrode 6 is inserted so as to be sandwiched between two sets of holding members 10 and 12 installed on the circuit board 8 corresponding to the position of the secondary electrode 6, and at least the secondary electrode 6 and the holding member 12 are inserted at the time of this insertion. It is configured by being mounted on the circuit board 8 with the conductive rubber 16 interposed therebetween.

  Since the piezoelectric transformer according to the first embodiment is configured only by a simple structure in which the piezoelectric ceramic 2 is held by the holding members 10 and 12, there is no need to house the piezoelectric ceramic 2 in a case body and package it. . For this reason, the number of parts and its manufacturing man-hours can be greatly reduced, which can greatly contribute to the reduction of manufacturing costs. Further, since it is not necessary to accommodate the piezoelectric ceramic 2 in a resin case or the like, the mounting height can be suppressed accordingly.

  In addition, since the piezoelectric ceramic 2 is held in a state of being sandwiched between the holding members 10 and 12, work such as soldering and bonding is not required for mounting, and reworking when correcting the mounting position (rework). There is an advantage that becomes easier. Further, even when the piezoelectric ceramics 2 are sandwiched and held by the holding members 10 and 12 as described above, the conductive rubbers 14 and 16 interposed are elastically deformed in accordance with the vibration of the piezoelectric ceramics 2 and do not hinder the vibration. Therefore, the piezoelectric effect by the piezoelectric ceramic 2 is not impaired.

[Second Embodiment]
Next, the piezoelectric transformer according to the second embodiment will be described. In the following description, members that are the same as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions of matters common to the first embodiment are omitted.

  FIG. 4 is a perspective view showing the piezoelectric transformer of the second embodiment. FIG. 5 is a longitudinal sectional view of the piezoelectric transformer taken along line VV in FIG. The second embodiment is different from the first embodiment in that wire-filled rubbers 140 and 160 are interposed between the holding members 10 and 12 and the primary electrode 4 and the secondary electrode 6. The wire-containing rubbers 140 and 160 have, for example, a structure in which innumerable metal wires extending in the same direction (thickness direction) are distributed and arranged in the longitudinal direction and the width direction inside a rubber sheet material. Both ends of each wire are exposed on both sides of the sheet material, but the wires are insulated. For this reason, the rubber | gum containing wires 140 and 160 exhibits electroconductivity only in the thickness direction, and does not have electroconductivity in the other direction.

  As shown in FIG. 5A, the wire-containing rubber 140 is wound over about a half circumference around the trunk of the piezoelectric ceramic 2. In this state, the wire-filled rubber 140 electrically connects each primary electrode 4 and the holding member 10.

  FIG. 5B shows the internal structure of the wire-filled rubber 140 in detail. The internal wire 140a is embedded in a slightly curved state in advance, and the wire-containing rubber 140 is sandwiched between the primary electrode 4 and the holding member 10 in the thickness direction, so that the wire 140a interposed between them is interposed. Both ends are strongly pressed against the primary electrode 4 and the holding member 10 to electrically connect them. Even in this state, since the wires 140a are insulated from each other as described above, the primary electrodes 4 on both sides are not short-circuited.

  In the case of the above-described second embodiment, since the rubbers 140 and 160 with wires wound around the outer surface of the piezoelectric ceramic 2 can be inserted between the holding members 10 and 12 during mounting, workability is improved. Is better. Here, the rubbers 140 and 160 with wires are used here, but an anisotropic rubber material having conductivity only in the thickness direction may be used.

[Third Embodiment]
FIG. 6 is a perspective view showing the piezoelectric transformer of the third embodiment. The piezoelectric transformer according to the third embodiment includes a base substrate 80, and the piezoelectric ceramic 2 is mounted on another circuit substrate via the base substrate 80. Four rod-shaped holding members 100 and 120 are attached to the base substrate 80 so as to penetrate therethrough. These holding members 100 and 120 protrude on the mounting surface of the base substrate 80 at positions corresponding to the primary electrode 4 and the secondary electrode 6 of the piezoelectric ceramic 2 respectively. The two holding members 100 corresponding to the primary electrode 4 and the one holding member 120 corresponding to the secondary electrode 6 are covered with the conductive rubber 30 on the portions protruding from the mounting surface of the base substrate 80, respectively. . The remaining one holding member 120 is covered with a rubber 32 that is not particularly conductive.

  As indicated by arrows in the figure, when the piezoelectric ceramic 2 is inserted between the two sets of holding members 100 and 120, the holding members 100 and 120 correspond to the primary electrode 4 and the secondary electrode 6, respectively. The piezoelectric ceramic 2 is held so as to be sandwiched in the thickness direction. In this state, the conductive rubber 30 is interposed between the primary electrode 4 and the secondary electrode 6 and the holding members 100 and 120 to constitute an electrical connection therebetween.

  In the third embodiment, with the piezoelectric ceramics 2 attached to the base substrate 80, these can be handled as one piezoelectric transformer component (half-package component). In such a form of the piezoelectric transformer component, the portions of the holding members 100 and 120 protruding from the surface (the lower surface in the drawing) opposite to the mounting surface of the base substrate 80 become the lead terminals. Therefore, in the case of the third embodiment, it can be mounted (through-hole mounting) in the form of a piezoelectric transformer component on another circuit board on which a wiring pattern is formed.

[Fourth Embodiment]
FIG. 7 is a perspective view showing the piezoelectric transformer of the fourth embodiment. The difference from the first embodiment is that a socket-shaped holding member 34 is first provided on the mounting surface of the circuit board 8. The socket-shaped holding member 34 is made of a conductor such as metal and is connected to a wiring pattern (not shown) on the circuit board 8.

  As shown in FIG. 7A, the holding member 34 has an insertion port 34a into which the end of the piezoelectric ceramic 2 can be inserted. The insertion opening 34a opens in a direction along the mounting surface of the circuit board 8 (horizontal direction in the figure). Further, a conductive rubber 36 is attached inside the insertion port 34a.

  As shown in FIG. 7B, when the end of the piezoelectric ceramic 2 is inserted into the insertion port 34 a, the holding member 34 holds the piezoelectric ceramic 2 at a portion corresponding to the secondary electrode 6. In this state, the conductive rubber 36 is interposed between the secondary electrode 6 and the holding member 34 to electrically connect the secondary electrode 6 and the holding member 34.

  The difference from the other first embodiment is that a pin-shaped holding member 38 is provided corresponding to the primary electrode 4. Furthermore, in 4th Embodiment, these electrical connection is performed by adhere | attaching between each holding member 38 and the primary electrode 4 with the electroconductive adhesive 40. FIG.

  As described above, the piezoelectric transformer according to the fourth embodiment has a structure in which the end of the piezoelectric ceramic 2 (the end corresponding to the secondary electrode 6) is held in a state of being inserted into the socket-shaped holding member 34. In such a structure, the piezoelectric ceramic 2 is not easily detached from the holding member 34, so that the piezoelectric ceramic 2 can be easily and reliably held even when the pin-shaped holding member 38 is used at a position corresponding to the primary electrode 4. It can be done, and the mounting work becomes easier.

[Fifth Embodiment]
FIG. 8 is a perspective view showing the piezoelectric transformer of the fifth embodiment. The fourth embodiment is different from the first embodiment in that the portion corresponding to the primary electrode 4 is held by the pin-shaped holding member 38, but the fifth embodiment is the same leaf spring as the first embodiment. A shaped holding member 10 is used. In this case, as shown in FIG. 8A, the end portion of the piezoelectric ceramic 2 (the end portion corresponding to the secondary electrode 6) is inserted into the socket-shaped holding member 34, and further held in the form of a leaf spring. The piezoelectric ceramic 2 can be mounted on the circuit board 8 by inserting a portion corresponding to the primary electrode 4 between the members 10. Therefore, unlike the fourth embodiment, it is not necessary to bond using the conductive adhesive 40.

  Similarly, in the piezoelectric transformer of the fifth embodiment, the piezoelectric ceramic 2 is less likely to drop off from the holding member 34. Further, by holding the piezoelectric ceramic 2 by the same holding member 10 as in the first embodiment at a position corresponding to the primary electrode 4, it can be easily and reliably held while preventing the piezoelectric ceramic 2 from falling off. .

  The present invention can be implemented with various modifications without being limited to the above-described embodiments (first to fifth).

  In the first embodiment, two sets of holding members 10 and 12 are used to hold the piezoelectric ceramic 2. However, if the vibration of the piezoelectric ceramic 2 is not inhibited, the holding members 10 and 12 are set to three sets (three places) or more. It may be used to hold the piezoelectric ceramic 2.

  In the second embodiment, the sheet-like rubbers 140 and 160 are half-circulated around the waist of the piezoelectric ceramic 2. However, the wire-containing rubbers 140 and 160 are formed in a ring shape so that they surround the circumference of the piezoelectric ceramic 2. You may let them.

  About 3rd Embodiment, the holding members 10 and 12 of 1st Embodiment are formed on the attachment surface of the base substrate 80, and the structure which provided the lead terminal which leads to the holding members 10 and 12 on the opposite surface is employ | adopted. May be. Further, the socket-shaped holding member 34 mentioned in the fourth and fifth embodiments may be applied to the third embodiment.

  In addition, the shapes and structures of the members and components described in the embodiments are merely preferred examples, and it goes without saying that the present invention can be implemented by appropriately modifying them.

It is the perspective view which showed the piezoelectric transformer of 1st Embodiment. FIG. 2 is a horizontal sectional view of the piezoelectric transformer taken along line II-II in FIG. 1. 2 is a circuit diagram schematically showing an electrical configuration of a piezoelectric transformer. FIG. It is the perspective view which showed the piezoelectric transformer of 2nd Embodiment. It is a longitudinal cross-sectional view of the piezoelectric transformer which follows the VV line in FIG. It is a perspective view which shows the piezoelectric transformer of 3rd Embodiment. It is a perspective view which shows the piezoelectric transformer of 4th Embodiment. It is a perspective view which shows the piezoelectric transformer of 5th Embodiment.

Explanation of symbols

2 Piezoelectric Ceramics 4 Primary Electrode 6 Secondary Electrode 8 Circuit Board 10, 12 Holding Member 14, 16 Conductive Rubber 18 Input Voltage Generator 20 Input Circuit 22 Output Circuit

Claims (6)

A plate-like piezoelectric body;
Each of the sides constituting the piezoelectric body is formed on each of two outer surfaces that are paired in the thickness direction along the side having the shortest length, and mechanically by inputting a periodic voltage to the piezoelectric body. A primary electrode for generating a vibration,
A secondary electrode that is formed on the outer surface of the piezoelectric body separately from the primary electrode, converts the vibration generated by the input of the voltage from the primary electrode into a voltage, and outputs the voltage,
A circuit board on which an input circuit connected to the primary electrode and an output circuit connected to the secondary electrode are respectively formed;
The piezoelectric body is held on the mounting surface of the circuit board and sandwiched in the thickness direction at least at a portion corresponding to the primary electrode and the secondary electrode, and the primary electrode and the secondary electrode are held in this holding state. Holding members for connecting the secondary electrodes to the output circuit and the input circuit, respectively;
A conductive member that is provided between at least the holding member and the secondary electrode and is electrically connected between the holding member and the secondary electrode in a state where the piezoelectric body is held by the holding member. A piezoelectric transformer comprising an elastic body having a property. A plate-like piezoelectric body;
Each of the sides constituting the piezoelectric body is formed on each of two outer surfaces that are paired in the thickness direction along the side having the shortest length, and mechanically by inputting a periodic voltage to the piezoelectric body. A primary electrode for generating a vibration,
A secondary electrode that is formed on the outer surface of the piezoelectric body separately from the primary electrode, converts the vibration generated by the input of the voltage from the primary electrode into a voltage, and outputs the voltage,
A circuit board on which an input circuit connected to the primary electrode and an output circuit connected to the secondary electrode are respectively formed;
The piezoelectric body is held on the mounting surface of the circuit board and sandwiched in the thickness direction at least at a portion corresponding to the primary electrode and the secondary electrode, and the primary electrode and the secondary electrode are held in this holding state. Holding members for connecting the secondary electrodes to the output circuit and the input circuit, respectively;
The piezoelectric body is provided between the holding member, the primary electrode, and the secondary electrode in a state of being held by the holding member, and the holding member, the primary electrode, and the secondary electrode A piezoelectric transformer comprising: an elastic body having electrical conductivity that electrically connects each other. The piezoelectric transformer according to claim 2,
The elastic body is made of a sheet-like rubber material having conductivity only in the thickness direction, and the sheet-like rubber material surrounds the periphery from one of the two outer surfaces of the piezoelectric body to the other, and pairs in the thickness direction. A piezoelectric transformer, characterized in that the piezoelectric transformer is provided so as to be interposed between the holding member and the primary electrode in a state where one of the surfaces formed is in contact with the primary electrode. The piezoelectric transformer according to any one of claims 1 to 3,
The holding member is
A pair of leaf spring-shaped metal terminals that are arranged on the mounting surface of the circuit board at an interval and extend in a direction away from the mounting surface in a state where a base end portion is fixed to the mounting surface;
A piezoelectric transformer characterized in that the piezoelectric body is sandwiched and held by a portion corresponding to at least one of the primary electrode and the secondary electrode by the elastic force of the pair of metal terminals. The piezoelectric transformer according to any one of claims 1 to 3,
The holding member is
A socket-shaped main body having an insertion port that is installed on the mounting surface of the circuit board and opens in a direction along the mounting surface;
A piezoelectric transformer that holds the piezoelectric body by inserting an end portion of the piezoelectric body corresponding to the secondary electrode through the insertion port into the socket-shaped main body. A primary electrode for inputting a voltage to each of two outer surfaces that form a pair in the thickness direction along the side having the shortest length of one side among the sides is formed in each of the sides, and the primary Separately from the electrodes, a piezoelectric body in which a secondary electrode for outputting a transformed voltage is formed on the outer surface is installed on the mounting surface of the circuit board corresponding to the positions of the primary electrode and the secondary electrode, respectively. Inserted while being sandwiched between the two sets of holding members in the thickness direction ,
Upon insertion of the piezoelectric body with respect to the holding member, by mounting on the circuit board while interposing an elastic body having conductivity is between the holding member and at least the secondary electrodes, the circuit board A periodic voltage is applied to the piezoelectric body through the primary electrode with the input circuit formed on the primary electrode connected to the primary electrode and the output circuit formed on the circuit board connected to the secondary electrode. 2. The piezoelectric transformer according to claim 1, wherein the piezoelectric transformer is configured to convert a mechanical vibration of the piezoelectric body generated by the input of the voltage into a voltage and output the voltage from the secondary electrode. Mounting method of piezoelectric transformer.

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