JP2000252088A - Piezoelectric inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen an input and output wiring while strongly supporting a piezoelectric transformer by forming the structure for supporting the piezoelectric transformer assembled on a circuit board into a structure using cushions to be held by a plate spring-like fitting working as an electrode and a fitting. SOLUTION: The structure for supporting a piezoelectric transformer is formed of cushions 7, 8 such as silicon resin having elasticity or an unified material thereof, cushions 5, 6 for covering an upper surface, a lower surface and side surfaces of a piezoelectric ceramics 1, electrical wiring of an input electrode 2, a plate 9 working as a presser for the cushions 5, 6 and a cover 10 for reinforcing the plate 9. The plate 9 and the covers 10, 11 are fixed to a circuit board by soldering, adhesion or bending. The cushions 5, 6 are fixed to the ceramic 1, the input electrodes 2, 3, the plate 9, and the circuit board. Cushions 7, 8 are fixed to the ceramic 1, the cover 11 and the circuit board. Furthermore, the plate 9 and the cover 10 are unified with each other by the adhesive agent or a pressure sensitive adhesive double coated tape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to piezoelectric inverters for backlights of personal computers and the like. More specifically, the present invention relates to a mounting structure of a ceramic type piezoelectric transformer of a piezoelectric inverter.

[0002]

2. Description of the Related Art An inverter for turning on a backlight such as a cold cathode tube of a notebook personal computer is, for example, a 6-bit inverter.
Since a high voltage of about 00 V is required, an inverter of a type in which a power supply voltage is boosted by using a winding transformer has been used. However, in recent years, notebook computers have been rapidly reduced in size and weight, and as a result, winding transformers cannot be made thinner. Therefore, a piezoelectric inverter capable of realizing a thin and highly efficient inverter has been attracting attention.

The piezoelectric transformer of a piezoelectric inverter generates a high voltage by boosting the voltage by vibrating a gum-like or rod-like polarized ceramic plate. Therefore, mounting methods that hinder the vibration of the piezoelectric transformer
It cannot be used because it lowers the power efficiency of the piezoelectric transformer. Therefore, it is supported at the position of the node of the vibration having the smallest vibration.

[0004] The structure of a piezoelectric transformer of a conventional piezoelectric inverter will be described. FIG. 2 is a perspective structural view showing a basic structure and a supporting structure of the piezoelectric transformer. Piezoelectric ceramics 1
Has a cubic structure, and includes piezoelectric input electrodes 2 and 3 provided above and below a piezoelectric ceramic 1 and a secondary output electrode 4 provided on a side surface that generates a high voltage. A transformer is configured. Input wiring 1 from each electrode
2, 13 and the output wiring 25 are drawn out by solder connection.
The piezoelectric transformer is supported and fixed with a case from above and below via cushions 19 to 24 having elasticity such as silicon resin. The positions of the cushions 19 to 24 are selected as locations that serve as nodes of vibration of the piezoelectric transformer.

[0005]

However, in order to maintain the power efficiency of the piezoelectric transformer at its best, the cushion of the fixing member is made as narrow as possible so as not to adversely affect the mechanical vibration of the piezoelectric transformer, and the position of the node is reduced. Must be placed precisely. As a result, if the performance of the piezoelectric transformer is to be maintained well, the supporting force of the piezoelectric transformer is weakened, the impact resistance is reduced, and the power efficiency is deteriorated because the position of the node is easily shifted with time. It will be easier.

Further, since the input wiring and the output wiring are exposed to mechanical vibrations of several tens to several hundreds of kHz, after a long period of time, metal fatigue gradually accumulates and eventually breaks.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve such problems. Specifically, a supporting structure for a piezoelectric transformer is made of a simple cushioning material and a leaf spring-like metal fitting that also serves as an electrode. And a structure that supports the piezoelectric transformer using a cushion held by metal fittings, while ensuring the maximum performance of the piezoelectric transformer, a structure that strongly supports, a structure that strengthens the input and output wiring, The purpose is to provide a structure that can streamline the manufacturing process.

In the piezoelectric inverter configured as described above, as can be seen from FIG. 1, the piezoelectric ceramic is firmly mounted and supported on the circuit board by the cushion, the electrode plate, and the cover, and the input electrode of the piezoelectric ceramic is input. Since the electrode plate also serves as a wiring function and the output electrode connection has a strong output wiring structure, it has excellent impact resistance and long-term reliability.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective structural view of a piezoelectric transformer according to the present invention. The piezoelectric ceramic 1 has a cubic structure, and has primary input electrodes 2 and 3 provided to face the piezoelectric ceramic 1 up and down and a secondary output electrode provided on a side surface that generates a high voltage. The basic structure of the piezoelectric transformer 4 is the same as the conventional one.

The piezoelectric transformer is supported by cushions 7 and 8 having elasticity such as silicone resin or cushions 7 and 8.
An integrated electrode 8, cushions 5, 6 for covering the upper, lower, and side surfaces of the piezoelectric ceramic 1, an electric wiring for the input electrode 2, and an electrode plate 9 serving as a holder for the cushions 5, 6.
The cover 10 further includes a cover 10 for reinforcing the electrode plate 9 and a cover 11 for holding the cushions 7 and 8. The electrode plate 9 and the covers 10, 11 are soldered, glued, or bent and fixed to the circuit board. The cushions 5 and 6 are made of ceramic 1 and input electrodes 2 with an adhesive or a double-sided tape.
3 is fixed to the electrode plate 9 and the circuit board. Similarly, the cushions 7, 8 are fixed to the ceramic 1, the cover 11, and the circuit board with an adhesive or a double-sided tape. Further, the electrode plate 9 and the cover 10 are also integrated with an adhesive or a double-sided tape.

The electrical connection between the input electrode 2 and the electrode plate 9 is made at the connection portion 14 by, for example, soldering. Electrode plate 9
The connecting portion 14 has a structure capable of supporting soldering at several places in order to increase the connection strength. The input wiring 13 is connected to the input electrode 3 at a connection portion 15. Output wiring 17
Is connected to the output electrode 4 at a plurality of locations by a connection portion 18.

FIG. 3 is a perspective structural view of the electrode plate of the present invention. The electrode plate 9 made of a resilient metal material connected to the input electrode 2 has a connection portion 14 and a region 2 supporting the connection portion 14.
6,27. The regions 26 and 27 have a large number of horizontally long holes. Therefore, the connecting portion 14 can easily move in the vertical direction, but is restricted in the horizontal direction of the length of the ceramic 1.

FIG. 4 is a perspective structural view of another electrode plate of the present invention. The electrode plate 9 made of a resilient metal material connected to the input electrode 2 includes a connection portion 14 and regions 28 and 29 supporting the connection portion 14 as in the embodiment of FIG.
However, the regions 28 and 29 have a structure bent a plurality of times. For this reason, the connecting portion 14 is vertically
Although it is easy to move, the movement is restricted in the longitudinal direction of the ceramic 1 in the horizontal direction.

FIG. 5 is a perspective structural view of an electrode plate for an input electrode on the opposite side according to the present invention. The electrode plate 30 made of a springy metal material connected to the input electrode 3 has a shape obtained by reducing the size of the electrode plate 9 in FIG. The connection portion 15 can easily move in the vertical direction, but is restricted in the horizontal direction in the longitudinal direction of the piezoelectric ceramic 1. The connection portion 15 is connected to the input electrode 3 at a portion serving as a node of vibration of the piezoelectric ceramics 1 by soldering or the like.

FIG. 6 is a perspective structural view of an output wiring according to the present invention. The output wiring 17 is connected to the electrical connection 1 with the output electrode 4.
8 are provided. The material is a soft film having a thin metal thin film as a wiring material so as not to hinder the vibration of the piezoelectric ceramics 1. Next, a manufacturing method will be described. (1) The piezoelectric ceramics 1 and the cushions 5 to 8 are bonded to the vibration nodes of the piezoelectric ceramics 1 using an adhesive or a double-sided tape.

(2) The connection portion 18 of the output wiring 17 is soldered to the output electrode 4. (3) The electrode plate 30 is fixed to the circuit board by soldering. (4) The circuit board and the piezoelectric ceramics 1 are adhered to each other with the adhesive or the double-sided tape via the cushions 5, 6, 8 so that the electrode plate 30 is located at the position of the node of the vibration of the piezoelectric ceramics 1.

(5) After covering the electrode plates 9 so as to cover the cushions 5 and 6, they are fixed to the circuit board by soldering. (6) After covering the cover 11 so as to cover the cushions 7 and 8, it is fixed to the circuit board by soldering. (7) The connection part 14 of the electrode plate 9 and the input electrode 2 are connected by soldering.

(8) The connection portion 15 of the electrode plate 30 and the input electrode 3 are connected by soldering through a hole provided in the circuit board. (9) After covering the cover 10 so as to cover the electrode plate 9, it is fixed to the circuit board by soldering. If the cover 10 and the electrode plate 9 are integrated with an adhesive or a double-sided tape, a strong structure is obtained.

(10) If necessary, a sound insulating plate and a high-voltage safety cover are adhered and fixed on the covers 10 and 11 with an adhesive or a double-sided tape.

[0020]

As described above, according to the present invention, the piezoelectric ceramic is fixedly mounted on the circuit board by the cushion, the electrode plate, and the cover, so that the piezoelectric ceramic can be mounted on the circuit board without adversely affecting the vibration of the piezoelectric ceramic. It is excellent in shock resistance because it can be mounted firmly on the board, and the process of mounting the case on the circuit board and wiring connection after fixing the piezoelectric ceramic in the case is not necessary, so it can be manufactured at low cost, and the electrode plate and input Since the electrodes, the output wiring, and the output electrode are connected with a strong structure, there is an effect that a piezoelectric inverter having a piezoelectric transformer with high long-term reliability of electrical connection can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective structural view of an embodiment of a piezoelectric transformer according to the present invention.

FIG. 2 is a perspective structural view of an embodiment of a conventional piezoelectric transformer.

FIG. 3 is a perspective structural view of an embodiment of the electrode plate of the present invention.

FIG. 4 is a perspective view of another electrode plate according to an embodiment of the present invention.

FIG. 5 is a perspective structural view of an electrode plate for an opposing input electrode of the present invention.

FIG. 6 is a diagram showing an output-side electrode lead-out wiring of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric ceramics 2, 3 ... Input electrode 4 ... Output electrode 5, 6, 7, 8 ... Cushion 9 ... Electrode plate 10, 11 ... Cover 17 ... Output wiring

Claims (5)

[Claims] 1. An inverter for lighting equipped with a piezoelectric transformer, wherein the piezoelectric transformer has a structure in which the piezoelectric transformer is assembled on a circuit board. 2. The piezoelectric transformer of a piezoelectric transformer is provided with an input electrode of the piezoelectric ceramic, two cushions for pressing a side surface of the piezoelectric ceramic, and an electrode plate for covering and fixing the cushion. Piezoelectric inverter. 3. The electrode plate includes a connection portion for electrically connecting to the input electrode and a region supporting the connection portion,
3. The piezoelectric inverter according to claim 2, wherein a number of elongated holes are opened in the area. 4. The electrode plate comprises a connecting portion for electrically connecting to the input electrode and a region supporting the connecting portion,
3. The piezoelectric inverter according to claim 2, wherein the region is zigzag bent a plurality of times. 5. The piezoelectric inverter according to claim 1, wherein the output wiring connected to the output electrode of the piezoelectric ceramic has a film shape having a plurality of connection portions.