JP2001177162A - Piezoelectric transformer and device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric transformer which is easy to handle when mounted on a circuit board, superior in shock resistance, and prevents poor contact due to the changeover aging. SOLUTION: The piezoelectric transformer has outer electrodes 13, 14 formed by baking and metal plates 15, 16 molten and connected to the outer electrodes 13, 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric transformer suitable for use in piezoelectric devices such as a piezoelectric inverter for a backlight of a liquid crystal display, and a piezoelectric transformer device having the same mounted on a circuit board.

[0002]

2. Description of the Related Art FIG. 2 illustrates a conventional piezoelectric transformer. FIG. 2A is an external view of the piezoelectric transformer, and FIG.
FIG. 2B is a development view of the piezoelectric transformer shown in FIG.

As shown in FIG. 2, a conventional piezoelectric transformer 101
Has a long piezoelectric plate 61 and piezoelectric plates 9 and 10,
9 'and 10' have a laminated structure in which layers are sequentially laminated. The piezoelectric plate 9 is formed with an input-side internal electrode 41, an input-side electrode lead-out portion 41a drawn out therefrom, and an output-side internal electrode 31. Here, the input-side electrode take-out portion 41a is taken out from the longer side of the piezoelectric plate 9.

The piezoelectric plate 10 has an input-side internal electrode 4
2 and the input-side electrode extraction portion 42 extracted therefrom
a and the output-side internal electrode 31a. Here, the input side electrode take-out part 42a is taken out from the side of the piezoelectric plate 9 opposite to the input side electrode take-out part 41a.

On the other hand, the input side internal electrode 4 is
1 'and the input-side electrode extraction portion 4 drawn out therefrom
1a 'and an output-side internal electrode 31b are formed. This has the same pattern as the piezoelectric plate 9 described above.

On the piezoelectric plate 10 ', an input-side internal electrode 42', an input-side electrode lead-out portion 42a 'drawn out therefrom, and an output-side internal electrode 31c are formed. This has the same pattern as the piezoelectric plate 10 described above. Note that no electrode is formed on the uppermost piezoelectric plate 61.

The piezoelectric transformer 101 has input electrode extraction portions 42a, 42 on both sides parallel to the longitudinal direction.
a 'first input-side external electrode 4 of the input-side high-voltage unit connected to a'
3, and a second input-side external electrode 44 of the input-side low-voltage portion connected to the input-side electrode extraction portions 41a and 41a '.

Further, an output-side external electrode 24 of the output-side high-voltage section connected to the output-side internal electrodes 31, 31a, 31b, and 31c on the side surface perpendicular to the longitudinal direction is provided.

The electrodes are formed by baking the laminate and then applying and baking a silver paste or the like to each position of the laminate.

FIG. 3 is a view showing a state in which the piezoelectric transformer 101 is mounted on the circuit board 23.

As shown in FIG. 3, the piezoelectric transformer 101 includes a spring-shaped terminal 21 and a second input-side external electrode 44 provided on a circuit board 23 and a spring-shaped terminal 21 and a first input-side external electrode 43 (shown in FIG. Not implemented), but are mounted so as to make electrical contact.

That is, the first and second input-side external electrodes 43 and 4 baked on the spring-like terminals 21 and 22 by the spring force of the spring-like terminals 21 and 22 by the spring force of the spring-like terminals 21 and 22.
4 are in direct contact with each other, and the electrical connection with the first and second input-side external electrodes 43 and 44 is ensured while being held on the circuit board 23.

The first and second input-side external electrodes 4
The reference numerals 3 and 44 are provided at the nodes of the piezoelectric vibration and are designed to reduce the influence of the vibration.
It is designed so that the force of the springs 1 and 22 is increased and pressed down.

[0014]

However, since the baked external electrode has a fragile surface, the spring force cannot be increased so much, and it is difficult to increase impact resistance and the like. . In addition, care must be taken when handling during installation.

Further, it is necessary to pay attention to poor contact caused by oxidization of the electrode and crushing of silver particles with time of the baked external electrode.

Accordingly, it is an object of the present invention to provide easy handling when mounting on a circuit board, and excellent impact resistance.
Another object of the present invention is to provide a piezoelectric transformer in which contact failure due to aging is prevented, and a piezoelectric transformer device in which the piezoelectric transformer is mounted on a circuit board.

[0017]

According to the piezoelectric transformer of the present invention, the external electrode is strengthened by soldering a metal plate to the external electrode formed by baking, and the piezoelectric transformer is handled when mounted on a circuit board. And the impact resistance is improved.

That is, the present invention relates to a piezoelectric transformer in which external electrodes are formed by baking on the side surfaces of a laminated body formed by laminating a plurality of long plate-shaped piezoelectric plates provided with internal electrodes on one surface. A piezoelectric transformer characterized in that a plate is fusion-connected.

Further, the present invention is the above-described piezoelectric transformer, wherein the fusion connection is performed by soldering.

Further, the present invention is a piezoelectric transformer device characterized in that the above-mentioned piezoelectric transformer is held on a circuit board with two or more spring-like terminals fixed on the circuit board.

Further, according to the present invention, a piezoelectric transformer, in which external electrodes are formed by baking, is fixed on a circuit board on a side surface of a laminated body in which a plurality of long plate-shaped piezoelectric plates provided with internal electrodes on one surface are laminated. A piezoelectric transformer device sandwiched and held by two or more spring-like terminals, wherein a flat metal plate is interposed between the external electrode and the spring-like terminal.

[0022]

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

FIG. 1 is an explanatory diagram of a piezoelectric transformer according to an embodiment of the present invention. FIG. 1A is a perspective view of the piezoelectric transformer, and FIG. 1B is a front view of the transformer.

In FIG. 1, a piezoelectric transformer 100 has a first input external electrode 13 provided on one of two side surfaces parallel to the longitudinal direction, and a second input external electrode 14 provided on the other side. . Output side external electrodes 2 are provided on side surfaces perpendicular to the both side surfaces.

The burned-in input side external electrode 1
Planar metal plates 15 and 16 are soldered to 3 and 14, respectively. On the circuit of the circuit board 23, substantially L-shaped spring-like terminals 11, 12 are fixed.

The piezoelectric transformer 100 includes metal plates 15 and 16 soldered to both side surfaces of the piezoelectric transformer 100, respectively.
12 and held on the circuit board 23. Thus, the piezoelectric transformer 100 is held on the circuit board 23 by the force of the springs of the spring-like terminals 11 and 12, and is electrically connected to the circuit on the circuit board 23.

Here, the spring force of the spring-like terminals 11 and 12 is applied to the external electrodes 13 and 14 which are baked through the metal plates 15 and 16. Further, since the metal plates 15 and 16 are flat, the force of the spring is dispersed and the fragile burned electrode is not crushed.

Therefore, even if a strong spring material is used for the spring-like terminals 11 and 12, the external electrodes 13 and 14 are not damaged, so that the piezoelectric transformer 100 can be firmly held on the circuit board 23. It becomes possible. Therefore, impact resistance can be improved.

Further, the external electrodes 13 and 14 are
Since it is in the state protected by 5 and 16, handling at the time of mounting on the circuit board 23 becomes easy.

The external electrodes 13 and 14 are connected to the metal plate 1.
Since solders 5 and 16 are soldered, poor contact due to oxidization of the external electrodes and aging can be suppressed, unlike mere contact.

In this embodiment, the metal plates 15 and 16 are soldered to the external electrodes 13 and 14, respectively. However, the metal plates 15 and 16 may be soldered to the spring terminals 11 and 12. Alternatively, the metal plate and the spring-like terminals 11 and 12 may be formed integrally.

However, in this case, care must be taken in handling when mounting on a circuit board. Although this does not contribute much to poor contact due to aging of the external electrodes, since the contact side is flat, The spring force is dispersed and can be firmly held on the circuit board 23. Further, the impact resistance is also improved.

[0033]

As described above, according to the present invention, a piezoelectric transformer which is easy to handle at the time of mounting on a circuit board, suppresses poor contact due to aging, and has excellent shock resistance, and A piezoelectric transformer device having a piezoelectric transformer mounted on a circuit board can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a piezoelectric transformer according to an embodiment of the present invention. FIG. 1A is a perspective view of the piezoelectric transformer. FIG.
(B) is a front view of the piezoelectric transformer.

FIG. 2 is an explanatory diagram of a conventional piezoelectric transformer. FIG. 2 (a)
FIG. 2 is a perspective view of the piezoelectric transformer. FIG. 2B is a developed view of FIG. 2A.

FIG. 3 is a diagram showing a state in which a conventional piezoelectric transformer is mounted on a circuit board.

[Explanation of symbols]

2, 24 (output side) external electrode 9, 9 ', 10, 10' piezoelectric plate 11, 12, 21, 22 spring-like terminal 13, 43 (first input side) external electrode 14, 44 (second input Side) External electrode 15, 16 Metal plate 23 Circuit board 31, 31a, 31b, 31c Output-side internal electrode 41, 41 ', 42, 42' Input-side internal electrode 41a, 41a ', 42a, 42a' Input-side electrode take-out part 61 piezoelectric plate 100,101 piezoelectric transformer

Claims (4)

[Claims] 1. A piezoelectric transformer in which external electrodes are formed by baking on the side surfaces of a laminated body in which a plurality of long plate-shaped piezoelectric plates having internal electrodes provided on one surface are laminated, and a metal plate is melt-connected to the external electrodes. A piezoelectric transformer characterized by the following. 2. The piezoelectric transformer according to claim 1, wherein the fusion connection is performed by soldering. 3. A piezoelectric transformer device wherein the piezoelectric transformer according to claim 1 or 2 is held on a circuit board by being sandwiched between two or more spring-like terminals fixed on the circuit board. 4. Two or more piezoelectric transformers each having a piezoelectric transformer formed by baking and forming an external electrode on a side surface of a laminate formed by laminating a plurality of long plate-shaped piezoelectric plates provided with internal electrodes on one surface. A piezoelectric transformer device sandwiched and held by a spring-like terminal, wherein a flat metal plate is interposed between the external electrode and the spring-like terminal.