JPH10173251A - Piezoelectric transformer power supply - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric transformer power supply capable of preventing a solder defect at a connection point between a piezoelectric transformer and a flexible insulating sheet. SOLUTION: In the piezoelectric transformer power supply of the present invention, the fixing position between the flexible insulating sheet and the circuit board is set from the conductive pattern electrically connected to the connection point between the piezoelectric transformer and the flexible insulating sheet. Is off. Thereby, the connection failure between the piezoelectric transformer and the flexible insulating sheet is eliminated. As a result, it is possible to provide a piezoelectric transformer power supply that can secure sufficient reliability, reduce the number of components and the mounting area, and can achieve downsizing, low profile, and low cost.

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, and more particularly to a piezoelectric transformer power supply for realizing a highly reliable, compact, and low-profile 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. 2 and 3, input electrodes 13 a and 13 b capable of inputting and outputting power and an output electrode 14 are formed on the surface or side surface of the piezoelectric vibrator 12, respectively. In addition, input electrodes 13a,
Electric power is extracted by directly soldering the lead wires 31a, 31b, 32 to 13b or by disposing spring-like conductors 41a, 41b, 42.

In general, piezoelectric transformers are required not only to have high reliability but also to be reduced in size, height, and cost.

However, as shown in FIGS. 2 and 3, since the piezoelectric transformer is connected to the piezoelectric transformer by a lead wire or the like, there is a disadvantage that the mounting area and man-hour are enormous even if the piezoelectric transformer is reduced in size and height. . As an alternative, a case 11 into which a piezoelectric transformer composed of a ceramic rectangular plate 12 as shown in FIG. 4 is inserted is placed on a circuit board 19 via a flexible insulating sheet 15 having a plurality of linear conductor patterns. There is a conventional example of a fixed structure. This conventional example has the advantage that it can be reduced in size and height and does not require assembling man-hours.

[0005]

However, the connection points of the piezoelectric transformer and the flexible insulating sheet by soldering are connected by a conductive pattern for fixing the position of the flexible insulating sheet to the circuit board. When soldering and fixing the conductive insulating sheet to the circuit board, there is a problem that the solder at the connection point between the piezoelectric transformer and the flexible insulating sheet is melted through the conductive pattern, resulting in poor connection.

It is an object of the present invention to provide a piezoelectric transformer power supply capable of preventing defective soldering at a connection point between a piezoelectric transformer and a flexible insulating sheet.

[0007]

According to the present invention, a circuit board on which a plurality of lands are formed, a flexible insulating sheet provided with a plurality of linear conductor patterns, and And a piezoelectric transformer having 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 of the piezoelectric transformer. While electrically connected to the plurality of linear conductor patterns,
An insulating cover case having a recess for accommodating a pin for supporting and fixing the piezoelectric transformer and integrating the piezoelectric transformer and the flexible insulating sheet,
A piezoelectric transformer power supply is provided in which the pins are provided at a distance from the conductor pattern of the flexible insulating sheet and are fixed to the insulating cover case, the flexible insulating sheet, and the circuit board. .

[0008]

A pin is provided at a fixed position between the flexible insulating sheet and the circuit board, and is displaced from the conductive pattern of the flexible insulating sheet. As a result, the solder connection point between the piezoelectric transformer and the flexible insulating sheet is also separated from the pin position. Therefore, the poor electrical connection between the piezoelectric transformer and the flexible insulating sheet is eliminated. It is possible to provide a piezoelectric transformer power supply that can ensure sufficient reliability, suppress the number of components and the mounting area, and can achieve downsizing, low profile, and low cost.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to a piezoelectric transformer power supply of the present invention.

The piezoelectric transformer power supply of the present invention is characterized in that the conductor pattern of the flexible insulating sheet is provided separately from the pins.

Hereinafter, the present invention will be described specifically with reference to embodiments.

[0012]

FIG. 1 is a perspective view showing an example of the configuration of a piezoelectric transformer power supply according to an embodiment of the present invention. As shown in FIG. 1, a piezoelectric transformer (piezoelectric vibrator made of a piezoelectric ceramic rectangular plate) 12 has a plurality of internal conductors therein, and a pair of input electrodes having electrical connections alternately with these internal electrodes. External electrodes are formed, and the output electrode 17 is also used as the oscillator rectangular plate 1.
2 was formed on the end face. Here, the dimensions of the piezoelectric transformer piezoelectric ceramic rectangular plate 12 are 50 mm × 6 mm × 1.5 mm, and PZT-based ceramics are used.
Pd was integrally sintered, and the external electrode was formed by baking Ag. Next, the piezoelectric transformer 12 is inserted into the concave portion of the resin insulating cover case 11. The case 11 was formed by injection molding so as to be supported and fixed at a vibration node. Where 11
a to d are insertion pins.

On the other hand, the connection land 1 with the piezoelectric transformer 12
A flexible insulating sheet (FPC) 15-1 having 7a, 17b, 18 and openings 16a to 16d is formed. Input electrodes 13a, 13b of piezoelectric transformer 12, output electrode 1
4 and the lands 17a, 17b, and 18 of the FPC 15-1 are electrically connected one-to-one, thereby connecting the power of the piezoelectric transformer 12 to the external circuit board 19 and further connecting the case pins 11a to 11d to the FPC 15-1. Opening 16a
To 16d, and the openings 19a to 19 of the circuit board 19
d. Here, the opening 19 of the circuit board 19
a to 19d are formed at positions 3 mm from the end face of the piezoelectric transformer 12.

Table 1 shows a comparison of characteristics between the structure of the piezoelectric transformer power supply of the present invention using the FPC 15-1 of the present invention, the structure using the conventional FPC 15 and the structure of a piezoelectric transformer power supply using lead wires. At this time, the piezoelectric transformer was an integrally laminated product (10 layers), and a cold cathode tube of φ2 × 200 mm was used. As can be seen from Table 1, the piezoelectric transformer power supply of the present invention achieves the same characteristics while realizing a significant downsizing as compared with a structure using a lead wire. Even in the case of using the same FPC, in the conventional example, a contact failure occurs and the yield is deteriorated. Table 2 shows the results of aging of the piezoelectric transformer power supply of this example. It can be seen that even after 1000 hours, the characteristics hardly deteriorated and the reliability was secured.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

As described above, according to the piezoelectric transformer power supply of the present invention, the electrical connection between the piezoelectric transformer and the flexible insulating sheet does not occur.
In addition, the practical effect is extremely large because the size and height can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a piezoelectric transformer power supply according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional piezoelectric transformer.

FIG. 3 is a diagram showing another conventional example of the piezoelectric transformer of FIG. 2;

FIG. 4 is an exploded perspective view showing a conventional example of a piezoelectric transformer using an FPC.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Case 11a-11d Case pin 12 Ceramic rectangular plate (piezoelectric oscillator or piezoelectric transformer) 13a, 13b Input electrode 14 Output electrode 15-1 Flexible sheet (FPC) of the present invention 15 Conventional flexible sheet (FPC) 16a to 16d Openings of flexible sheet 17a, 17b Connection lands for input electrodes 18 Connection lands for output electrodes 19 Circuit boards 19a to 19d Openings for case fixing 21a, 21b, 21c Lands 31a, 31b Input lead wires 32 output lead wire 41a, 41b input leaf spring 42 output leaf spring

Claims (1)

[Claims] A circuit board on which a plurality of lands are formed; a flexible insulating sheet provided with a plurality of linear conductor patterns;
A piezoelectric transformer disposed on the flexible insulating sheet and having at least one pair of input electrodes for inputting electric power and at least one output electrode for extracting electric power; and the input of the piezoelectric transformer. Electrodes and the output electrodes are electrically connected to the plurality of linear conductor patterns, and pins for supporting and fixing the piezoelectric transformer, and the piezoelectric transformer and the flexible insulating sheet are integrated. An insulating cover case having a concave portion for accommodating the above, wherein the pins are provided separately from the conductor pattern of the flexible insulating sheet, and the insulating cover case, the flexible insulating sheet, the circuit board, A piezoelectric transformer power supply characterized by a fixed position.