JPH10173250A - Piezoelectric transformer power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a piezoelectric transformer power supply which is capable of meeting a demand for miniaturization. SOLUTION: The piezoelectric transformer power supply is equipped with a flexible insulating sheet 21 smaller than the external dimension of a piezoelectric transformer. Electric connecting points between the flexible insulating sheet 21 and the piezoelectric transformer are arranged on one side of the piezoelectric transformer and electrically connected to lands 33a to 33d formed on the rear side of a circuit board 31 through the intermediary of through-holes 34a to 34d provided to the circuit board 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric transformer power supply using a piezoelectric transformer.

[0002]

2. Description of the Related Art A piezoelectric transformer is known as a device to which a piezoelectric ceramic rectangular plate is applied. At present, ceramics and lithium niobate single crystals are often used as vibrators for piezoelectric transformers.
As shown in the schematic diagrams of FIGS. 5 and 6, input external electrodes 12 a and 12 b capable of inputting and outputting power and an output electrode 13 are formed on the surface or side surface of a piezoelectric vibrator (ceramic rectangular plate) 11, respectively. Electric power is extracted by connecting lead wires 41a, 41b, 42 to electrodes formed on the vibrator.
Is directly soldered or a leaf spring for input (spring-like conductor)
The method of taking out at 51a, 51b and 52 has been general.

[0003] In general, piezoelectric transformers have high demands for high reliability, miniaturization, low profile, and low cost. However, it is said that these requirements cannot be sufficiently satisfied with the conventional piezoelectric transformer configuration. There were drawbacks.

That is, since the piezoelectric transformer is connected to the piezoelectric transformer by a lead wire or the like as shown in FIGS. 5 and 6, even if the piezoelectric transformer is reduced in size and height, the mounting area and man-hours become enormous. As an alternative to this, a piezoelectric transformer as shown in FIG. 7 may be replaced with a plurality of linear pattern conductors 23a to 23d.
There is a structure that is fixed on a circuit board via a flexible insulating sheet having the following. This structure has the advantages that it can be reduced in size and height and does not require assembling man-hours.

[0005]

However, the electrical connection points 22a to 22a between the piezoelectric transformer and the flexible insulating sheet.
2d is performed on the side surface of the piezoelectric transformer, and the conductive pattern of the flexible insulating sheet is formed outside the element. Therefore, there has been a problem that the demand for further miniaturization cannot be satisfied.

Accordingly, a technical object of the present invention is to obtain a piezoelectric transformer power supply that can satisfy the demand for miniaturization.

[0007]

According to the present invention, there is provided a flexible insulating sheet provided with a plurality of linear pattern conductors on one surface, at least one set of input electrodes for inputting electric power, and electric power. A piezoelectric transformer having at least one output electrode for taking out, electrically connecting the input electrode and the output electrode with the plurality of linear pattern conductors, and supporting and fixing the piezoelectric transformer; An insulating cover for integrally covering the piezoelectric transformer and the flexible insulating sheet, wherein one surface of the flexible insulating sheet is smaller than an outer dimension of the piezoelectric transformer. A piezoelectric transformer power supply is obtained.

[0008]

In order to extract power, a flexible insulating sheet having a linear pattern conductor is used. Since one surface of the flexible insulating sheet is smaller than the external dimensions of the piezoelectric transformer, power can be taken out only from one surface, not from the side surface of the thickness. As a result, high reliability, small size and low profile are realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a piezoelectric transformer power supply according to an embodiment of the present invention, an electrical connection between a flexible insulating sheet and a piezoelectric transformer is arranged in a piezoelectric transformer shape, and the electric connection is made through a through hole in a circuit board. The electrical connection with the circuit board is made. Thus, a circuit board substantially equal to the width of the piezoelectric transformer is used. As a result, it is possible to supply a piezoelectric transformer power supply that sufficiently secures reliability, and that is reduced in height and cost.

Embodiments of a piezoelectric transformer according to the present invention will be described in detail below with reference to the drawings.

[0011]

1 and 2 are a top view and a bottom view showing one embodiment of a piezoelectric transformer according to an embodiment of the present invention. FIG.
1 is a schematic diagram of a piezoelectric transformer used in an embodiment of the present invention. As shown in FIG. 1, the piezoelectric transformer has a plurality of input internal electrodes 15a and 15b (FIG. 4) inside a piezoelectric vibrator, that is, a ceramic rectangular plate 11, and has an electrical connection alternately with the internal electrodes. One set of input external electrodes 12
a, 12b, and external output electrodes 13, 14a, 1
4b was also formed on the end face of the ceramic rectangular plate 11. Here, the outer shape of the piezoelectric transformer, that is, the dimension of the ceramic rectangular plate 11 is 50 mm × 6 mm × 1.5 mm, using PZT ceramics, the internal electrodes are integrally sintered with Ag / Pd, and the external electrodes are formed by baking Ag. Formed.

Next, a land 22 for connection to the piezoelectric transformer is provided.
A flexible insulating sheet (FPC) 21 having a to d is formed. Input external electrodes 12a and 12b of the piezoelectric transformer,
FPC for output external electrodes 13, 14a, 14b
The lands 22a, 22b, 22c, and 22d at 21 are electrically connected one to one. Land 22 of FPC 21
a, 22c and 22d are electrically connected to lands 33a to 33d on the back side of the circuit board 31 through through holes 34a to 34d. Further, the piezoelectric transformer and the insulating flexible sheet (FPC) 2 are placed around the vibration node of the piezoelectric transformer by using insulating contraction tubes 35a and 35b.
1 and a circuit board were integrated. Table 1 shows a comparison of the characteristics of the piezoelectric transformer power supply between the embodiment of the present invention using the FPC 21, the conventional example using the conventional FPC 21, and the comparative example using the lead wire. At this time, the piezoelectric transformer is an integrated laminated product (10 layers) as shown in FIG.
A cold cathode tube of φ2 × 200 mm was used. As can be seen from Table 1, the piezoelectric transformer power supply of the embodiment of the present invention has the same FP
Compared with a conventional example using C and a comparative example using a lead wire, the same characteristics are obtained while realizing a significant miniaturization.

[0013]

[Table 1]

Table 2 shows the results of aging of the piezoelectric transformer power supply of this embodiment. It can be seen that the characteristics are hardly deteriorated even after 1000 hours, and the reliability is secured.

[0015]

[Table 2]

[0016]

As described above, by using the piezoelectric transformer power supply of the present invention, it is possible to use a circuit board substantially equal to the width of the piezoelectric transformer while maintaining the conventional characteristics, so that further miniaturization is possible. is there.

[Brief description of the drawings]

FIG. 1 is a top view of a piezoelectric transformer power supply according to an embodiment of the present invention.

FIG. 2 is a bottom view of the piezoelectric transformer power supply of FIG.

FIG. 3 is a perspective view of a piezoelectric transformer according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of the piezoelectric transformer power supply of FIG.

FIG. 5 is a perspective view of a conventional piezoelectric transformer.

FIG. 6 is a perspective view of a comparative example of a piezoelectric transformer using a spring-shaped conductor.

FIG. 7 is a top view of a conventional example of a piezoelectric transformer using an FPC.

[Explanation of symbols]

11 Piezoelectric vibrator (ceramic rectangular plate) 12a, 12b Input external electrode 13 Output external electrode (high voltage side) 14a, 14b Output external electrode (GND side) 15a, 15b Input internal electrode 16b Output external electrode ( 17b Output external electrode (GND side) 21 Flexible insulating sheet (FPC) 22a to 22d Land provided on flexible insulating sheet 21 for electrical connection with piezoelectric transformer (with piezoelectric transformer Electrical connection point with flexible insulating sheet) 23a to 23d Conductive pattern 31 Circuit board 32 Output connector 33a to 33d Land 22 of flexible insulating sheet 21
a, 22c, and 22d for electrical connection with the circuit board 31
Lands 34a-34d Through holes 35a, 35b Insulating contraction tubes 41a, 41b Input lead wires 42 Output lead wires 51a, 51b Input leaf springs (spring-like conductors) 52 Output leaf springs

Claims (4)

[Claims] 1. A flexible insulating sheet provided with a plurality of linear pattern conductors on one surface, at least one set of input electrodes for inputting power, and at least one output electrode for extracting power. And the input electrode and the output electrode are electrically connected to each other by the plurality of linear pattern conductors, and the piezoelectric transformer is supported and fixed to support the piezoelectric transformer and the flexible insulation. An insulating cover for covering the sheet so as to be integrated, wherein one surface of the flexible insulating sheet is smaller than an outer dimension of the piezoelectric transformer. 2. The piezoelectric transformer power supply according to claim 1,
A piezoelectric transformer power supply, wherein an electrical connection between the insulating cover, the flexible insulating sheet, and the piezoelectric transformer is disposed on one surface of the piezoelectric transformer facing a circuit board. 3. The piezoelectric transformer power supply according to claim 2,
A piezoelectric transformer power supply, wherein the circuit board includes lands for making electrical connection with the flexible insulating sheet, and the lands are provided with through holes. 4. The piezoelectric transformer power supply according to claim 2,
A piezoelectric transformer power supply, wherein the flexible insulating sheet includes a land for electrically connecting to the piezoelectric transformer, and a through hole is provided in the land.