JPH07202289A - Electrode connection structure of piezoelectric transformer - Google Patents

Abstract

PURPOSE:To remarkably improve durability and reliability by connecting an electrode of a piezoelectric transformer to a substrate side readily and by ensuring connection strength. CONSTITUTION:When an electrode 3 of a piezoelectric transformer 1 is connected to the side of a substrate B whereon a piezoelectric transformer 1 is mounted, a connection conductor surface 6 is provided to an upper side 2u of a plane piezoelectric ceramics 2 between a pair of electrodes 3, 4 provided in a longitudinal direction of the plane piezoelectric ceramics 2 constituting the piezoelectric transformer 1 with an insulation material 5 between. An electrode 3 provided to an end surface 2s of the plane piezoelectric ceramics 2 is connected to the side of the substrate B through the connection conductor surface 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric transformer electrode connection structure suitable for connecting electrodes of a piezoelectric transformer to a substrate such as a printed circuit board on which the piezoelectric transformer is mounted.

[0002]

2. Description of the Related Art Conventionally, an electrode is provided in a thickness direction and a length direction of a flat piezoelectric ceramic, and the primary voltage of a natural frequency determined by the length direction is applied to the electrode in the thickness direction. There is known a piezoelectric transformer that vibrates in the lengthwise direction due to a strain effect and can obtain a secondary voltage from the electrodes in the lengthwise direction (Japanese Patent Laid-Open No. 55-55).
-113388, JP-B-60-15343, etc.).

Further, since the piezoelectric transformer is accompanied by mechanical vibration during operation, when the piezoelectric transformer is directly mounted on the substrate, the vibration of the piezoelectric transformer is suppressed by the substrate, and the output characteristics of the piezoelectric transformer are destabilized or deteriorated. At the same time, there is a possibility that abnormal noise may be generated due to vibration or the piezoelectric transformer may be damaged.
The piezoelectric transformer is mounted in a state of being floated from the surface of the substrate by a spring, thereby preventing a harmful effect due to mechanical vibration (see Japanese Utility Model Laid-Open No. 55-124873).

[0004]

By the way, the piezoelectric transformer has a pair of electrodes (primary side electrodes) on the upper and lower surfaces on one side in the length direction of the flat plate piezoelectric ceramic, and at the same time, on the lower surface on the one side in the length direction of the flat plate piezoelectric ceramic. Since a pair of electrodes (secondary side electrodes) are provided on the end face of the other side and the other side, when the conventional mounting structure in which the piezoelectric transformer is floated from the substrate side by the above-mentioned spring is used, the electrode of the piezoelectric transformer can be easily attached to the substrate side. However, there was a problem that the connection strength could not be secured and the durability and reliability were poor.

The present invention solves the problems existing in the prior art as described above. The electrodes of the piezoelectric transformer can be connected to the substrate side very easily, and the connection strength is ensured to ensure durability and reliability. It is an object of the present invention to provide a piezoelectric transformer electrode connection structure capable of dramatically improving the electrical properties.

[0006]

The present invention provides a piezoelectric transformer 1
In the electrode connection structure C of the piezoelectric transformer when the electrode 3 of FIG. 1 is connected to the side of the substrate B on which the piezoelectric transformer 1 is mounted, in particular, a pair of electrodes provided in the length direction of the flat plate piezoelectric ceramics 2 forming the piezoelectric transformer 1. A connecting conductor surface 6 is provided on the upper surface 2u of the flat piezoelectric ceramic 2 between 3 and 4 via an insulating material 5, and an electrode 3 provided on the end surface 2s of the flat piezoelectric ceramic 2 is provided on the upper surface 2u via the connecting conductor surface 6 of the substrate. It is characterized in that it is connected to the B side.

In this case, the connecting conductor surface 6 has a connecting end portion 6s disposed at an intermediate position between the pair of electrodes 3 and 4 provided in the lengthwise direction of the flat plate piezoelectric ceramic 2, and the connecting end portion 6s and the flat plate piezoelectric material. It can be constituted by an intermediate connecting portion 6m for connecting the electrode 3 provided on the end surface 2s of the ceramic 2.

Further, the transformer accommodating hole 7 provided in the substrate 2
, The piezoelectric transformer 1 is accommodated without coming into contact with the substrate B, and the piezoelectric transformer 1 is supported by one or more supporting members 8a, 8b having both ends 8as ..., 8bs. The connecting conductor surface 6 is provided on the member 8a.
It can be configured by providing a conductor terminal 9 that contacts with the substrate B and is connected to the substrate B side.

[0009]

According to the electrode connection structure C of the piezoelectric transformer according to the present invention, first, the piezoelectric transformer 1 is accommodated in the transformer accommodating hole 7 provided in the substrate B without contacting the substrate B, and the piezoelectric In this state, the transformer 1 is supported by one or more supporting members 8a and 8b. In this case, both ends 8as of the support members 8a are fixed to the substrate B.
As a result, the piezoelectric transformer 1 is arranged on the same plane with respect to the board B, so that the piezoelectric transformer 1 does not project in the thickness direction of the board B, the board B as a whole can be made compact, and the mounting structure can be simplified. Be converted.

On the other hand, an insulating material 5 is interposed between the pair of electrodes 3 and 4 provided on the upper surface 2u of the flat plate piezoelectric ceramics 2 constituting the piezoelectric transformer 1 and provided in the lengthwise direction of the flat plate piezoelectric ceramics 2. A connecting conductor surface 6 is provided. Therefore, if the supporting member 8a is provided with the conductor terminal 9 that contacts the connecting conductor surface 6, the connecting conductor surface 6 and the conductor terminal 9 are electrically connected. The connecting conductor surface 6 is composed of the connecting end portion 6s and the intermediate connecting portion 6m, and the flat plate piezoelectric ceramics 2
Since the electrode 3 is connected to the electrode 3 provided on the end surface 2s, the electrode 3 is connected to the substrate B side via the connection conductor surface 6 (intermediate connection portion 6m, connection end portion 6s) and the connection terminal 9. This allows
The electrode 3 in the piezoelectric transformer 1 can be easily connected to the substrate B side, and the connection strength is secured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments according to the present invention will be described in detail with reference to FIGS.

First, the piezoelectric transformer 1 is prepared. As shown in FIG. 3, the piezoelectric transformer 1 has a flat plate piezoelectric ceramics 2 having a rectangular shape in a plan view, and an electrode 3 using a conductor is provided on an end face 2s on one side in the length direction of the flat plate piezoelectric ceramics 2. . Further, an electrode 21 using a conductor is provided on the upper surface of the half portion 2b on the other side in the length direction of the flat piezoelectric ceramic 2, and an electrode 4 using a conductor is provided on the lower surface of the half portion 2b.

On the other hand, in accordance with the present invention, the flat piezoelectric ceramics 2 is connected at the center in the longitudinal direction on the upper surface 2u of the half portion 2a on one side in the longitudinal direction at right angles to the longitudinal direction by using a conductor. The end portion 6s is provided, and the connecting end portion 6s and the electrode 3 are electrically connected by the intermediate connecting portion 6m using a conductor. In addition, a sheet-shaped insulating material 5 that prevents contact is provided between the connection end portion 6s and the intermediate connection portion 6m and the upper surface 2u.

Further, supporting members 8a and 8b are prepared. The support members 8a and 8b are integrally formed of an elastic material such as rubber. The support members 8a and 8b have the piezoelectric transformer 1 in the middle.
Has transformer supporting portions 8ai and 8bi having transformer supporting holes 8ah and 8bh in which
.., 8bs .. has fixing portions 8aj .., 8bj .. The fixed portion 8
.., 8bj ... are engagement recesses 8a that are locked to the board B side.
.., 8 bp ... are provided. Also, one support member 8a
As shown in FIG. 2, the upper support member 8au of the transformer support portion 8ai is provided with the connection terminal 9, and the other support member 8b has the upper support member 8bu and the lower support member 8bu as shown in FIG. The support member 8bd is provided with conductor terminals 22 and 22, respectively.

On the other hand, a board B such as a printed board on which the piezoelectric transformer 1 is mounted is provided with a transformer housing hole 7 larger than the piezoelectric transformer 1 as shown in FIG.

As a result, when mounting, the half portion 2a of the piezoelectric transformer 1 is press-fitted into the transformer support hole 8ah of the one support member 8a, and the support member 8a is attached to the half portion 2a.
While being positioned substantially in the center of a, the half portion 2b on the other side is press-fitted into the transformer support hole 8bh of the other supporting member 8b to position the supporting member 8b substantially in the center of the 2b. As a result, the conductor terminal 9 provided on the one support member 8a comes into contact with the connection end 6s as shown in FIGS.
And the electrode 3 are connected, and the conductor terminals 22 and 22 provided on the other supporting member 8b are connected to the electrodes 21 and 4, respectively. The conductor terminals 9 and the electrodes 3, and the conductor terminals 22 ... And the electrodes 21 (4) may be bonded by a conductive adhesive to ensure reliable conduction. Further, by utilizing the elasticity of the support members 8a, 8b, the engaging recesses 8ap ..., 8bp ... provided at both ends 8as ..., 8bs ... Of the support members 8a, 8b are provided with the inner edge of the transformer housing hole 7 provided in the board B. It fits into the portion 7e and is locked. At this time, be careful that the piezoelectric transformer 1 does not contact the substrate B. The conductor terminals 9, 22 ... Can be connected to a predetermined circuit pattern 24 ... on the substrate B side through the connection lead wires 23 ... (see FIGS. 3 and 7).

A circuit utilizing the piezoelectric transformer 1 is
For example, the respective conductor terminals 9 are used to make connections as shown in FIG. Thereby, the electrodes 21, 4 provided in the thickness direction
In the meantime, the primary voltage Vi of the natural frequency is applied from the power source P, and the flat piezoelectric ceramics 2 vibrates in the length direction by the electrostrictive effect. In addition, the electrodes 3 and 4 provided in the length direction
The transformed secondary voltage Vo is obtained from the load resistance R connected in between.

Therefore, since the piezoelectric transformer 1 is disposed on the same plane with respect to the substrate B, the piezoelectric transformer 1 does not project in the thickness direction of the substrate B, and the entire substrate B can be made compact and the mounting structure can be achieved. Is simplified.
Further, since the electrode 3 is connected to the substrate B side via the connecting conductor surface 6 (intermediate connecting portion 6m, connecting end portion 6s) and the conductor terminal 9, the electrode 3 of the piezoelectric transformer 1 and the substrate B side are easily connected. In addition, the connection strength is secured, and the durability and reliability can be improved.

5 and 6 show a modified embodiment.
FIG. 5 shows that the support members 8a and 8a are provided on the upper and lower surfaces of the piezoelectric transformer 1.
The groove portions 1s ... Engaging with b are provided. As a result, as shown in FIG. 6, the supporting members 8a ... Are engaged with the grooves 1s of the piezoelectric transformer 1 to be positioned, and the positional deviation is prevented.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, although the material for forming the support member is a rubber material,
Other materials such as synthetic resin and metal may be used. Also,
Although the structure of the supporting member is illustrated as an integral type, it may be a vertically or horizontally divided type. For example, the vertically divided type may be configured by an upper support portion and a lower support portion, and the piezoelectric transformer may be supported by being sandwiched between the support portions. in this case,
If a metal material is used for each support part, each support part also serves as a conductor terminal, and the connecting conductor surface can be directly connected to the substrate side through each support part. Other details, configuration, shape, quantity,
The materials and the like can be arbitrarily changed without departing from the scope of the present invention.

[0021]

As described above, the electrode connection structure of the piezoelectric transformer according to the present invention has an insulating material on the upper surface of the flat plate piezoelectric ceramic between a pair of electrodes provided in the length direction of the flat plate piezoelectric ceramic forming the piezoelectric transformer. Since the connection conductor surface is provided via the electrode and the electrode provided on the end surface of the flat plate piezoelectric ceramics is connected to the substrate side via the connection conductor surface, the following remarkable effects are obtained.

Electrical connection between the electrodes of the piezoelectric transformer and the substrate side can be made extremely easily, and by securing the connection strength, durability and reliability can be dramatically improved.

Since the piezoelectric transformer can be arranged on the same plane with respect to the substrate, the piezoelectric transformer does not project in the thickness direction of the substrate, the overall size of the substrate can be reduced, and the number of components at the time of mounting can be reduced. Can be reduced and the mounting structure can be simplified.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electrode connection structure according to the present invention,

FIG. 2 is a vertical cross-sectional view including conductor terminals in the electrode connection structure,

FIG. 3 is a perspective view of a piezoelectric transformer in the electrode connection structure,

FIG. 4 is a perspective view of a support member in the electrode connection structure,

FIG. 5 is a perspective view showing a part of a piezoelectric transformer according to a modified embodiment of the present invention,

FIG. 6 is a longitudinal sectional view showing a part of a mounting structure using a piezoelectric transformer according to a modified embodiment of the present invention,

FIG. 7 is a wiring diagram of a piezoelectric transformer in an electrode connection structure according to the present invention,

[Explanation of symbols]

 C electrode connection structure B substrate 1 piezoelectric transformer 2 flat plate piezoelectric ceramics 2u upper surface 2s end face 3 electrode 4 electrode 5 insulating material 6 connecting conductor surface 6s connecting end portion 6m intermediate connecting portion 7 transformer accommodating hole 8s ... both end portions 8a supporting member 8b supporting member 9 conductor terminals

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shinjiro Nagano 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture Totoki Equipment Co., Ltd. (72) Akihiko Takahashi, Nakajima, Kitakyushu, Kitakyushu, Fukuoka 2 No. 1-1 No. 1 Totoki Equipment Co., Ltd. (72) Inventor Yoshio Miyasaka 1163 Shimoice, Inari-cho, Nagano City, Nagano Nagano Japan Radio Co., Ltd.

Claims (3)

[Claims] 1. In an electrode connection structure of a piezoelectric transformer when connecting an electrode of the piezoelectric transformer to a substrate side on which the piezoelectric transformer is mounted, between a pair of electrodes provided in a length direction of a flat plate piezoelectric ceramic constituting the piezoelectric transformer. In the piezoelectric transformer, the connection conductor surface is provided on the upper surface of the flat plate piezoelectric ceramics via an insulating material, and the electrodes provided on the end faces of the flat plate piezoelectric ceramics are connected to the substrate side via the connection conductor surface. Electrode connection structure. 2. The connecting conductor surface comprises a connecting end portion disposed at an intermediate position between a pair of electrodes provided in the lengthwise direction of the flat piezoelectric ceramic, and an electrode provided on the connecting end portion and the end surface of the flat piezoelectric ceramic. The electrode connection structure for a piezoelectric transformer according to claim 1, further comprising an intermediate connection portion for connection. 3. A piezoelectric transformer is housed in a transformer housing hole provided in the substrate without contacting the substrate, and
The piezoelectric transformer is supported by one or more supporting members whose both ends are fixed to the substrate, and the supporting member is provided with conductor terminals that are in contact with the connecting conductor surface and are connected to the substrate side. The electrode connection structure of the piezoelectric transformer according to claim 1.