JPH08205287A - Electro-acoustic transducing body - Google Patents

Abstract

PURPOSE: To set a transducing body on the printed circuit board of an apparatus with only one face and to abolish drilling work for the printed circuit board by providing a pair of terminals which are held on the outer peripheral side wall of a lower case by U-shaped parts and are exposed to the outside face. CONSTITUTION: A piezoelectric diaphragm 3 is supported in a recessed groove of an upper case 5 and is held between thus recessed groove and a projecting part 6 of a lower case 7. u-shaped terminals are held on the outer peripheral side wall of the lower case 7 with metallic elasticity by U-shaped bending parts 10 and 13. After assembling, a turned-up bending part 11 or the U-shaped terminal 9 is brought into contact with a piezoelectric ceramic plate 2 by spring pressure, and a turned-up bending part 14 of the other U-shaped terminal 12 is brought into contact with a metallic substrate 1 by a spring pressure. At the time of mounting, parts exposed from the case outer peripheral side wall of U-shaped terminals 9 and 12 are soldering parts to the printed circuit board of the apparatus, and this transducing body is mounted by only the front side of the printed circuit board. Therefore, highdensity mounting is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer for bonding a piezoelectric ceramic plate to a metal substrate and inputting a voltage of a predetermined frequency between the piezoelectric ceramic plate and the metal substrate to cause flexural vibration to generate sound. It is about.

[0002]

2. Description of the Related Art In recent years, as electronic devices have been highly densely packaged, various electronic parts have been downsized, and there has been a need for surface mounting capable of mounting without making a hole for a printed wiring board of the device. Expanded, there is a strong need for electroacoustic transducers.

A conventional electroacoustic transducer will be described below. FIG. 4 is a cross-sectional view showing a state in which an assembled piezoelectric sounding body as a conventional electroacoustic transducer is mounted on a printed wiring board of a device.

Reference numerals 21 and 22 are an upper case and a lower case.
A piezoelectric vibrating plate in which a metal plate 3 and a piezoelectric ceramic plate 24 are bonded together is sandwiched and housed, and contacts the terminals 25 and 26 respectively to make an electrical connection. It is mechanically pushed and held. The upper and lower cases 21 and 22 are fitted with the projections 30 and 32 and the concave grooves 29 and 31, and the terminals 25 and 26 are fitted with the case hole 2.
7 and 28 are matingly inserted to form a piezoelectric sounding body.
The holes 34, 3 formed in the printed wiring board 33 of the device
Insert terminals 25 and 26 into 5 and solder 36 and 37
Connected by A voltage signal having a predetermined frequency is applied to a piezoelectric sounding body through a printed wiring board to cause flexural vibrations in a piezoelectric ceramic plate and a metal substrate, thereby generating a sound.

[0005]

According to the conventional example configured as described above, the terminals 25 and 26 must be soldered on the back surface of the printed wiring board. Therefore, both sides of the printed wiring board of the device were required to mount the piezoelectric speaker. Further, it is necessary to form a hole for inserting the terminal of the piezoelectric sounding body in the printed wiring board of the device.

Further, in order to automatically mount the piezoelectric sounding body, it is necessary to insert the terminals of the piezoelectric sounding body terminals 25 and 26 aiming at the holes 34 and 35 of the printed wiring board. High processing accuracy is required for hole processing of the substrate, operation of an automatic machine, and the like, and there is a problem that productivity is impaired.

The present invention solves the above-mentioned problems of the prior art, does not require a mounting area on both sides of the printed wiring board of the device, can be mounted on only one side, and the hole processing of the printed wiring board can be eliminated. It is an object of the present invention to provide an electroacoustic transducer that is capable of being easily mounted on a printed wiring board automatically.

[0008]

In order to achieve the above object, the electroacoustic transducer of the present invention is a piezoelectric vibrating plate in which a piezoelectric ceramic plate is attached to a metal substrate, and a thin metal plate is U-shaped. The upper case and the lower case, to which a pair of terminals having elasticity are attached by repeatedly bending one end thereof, are fixed.

[0009]

With this configuration, since the surface mounting connection can be made by the pair of terminals that are sandwiched by the U-shaped portion on the outer peripheral side wall of the lower case and exposed on the outer surface, the printed wiring board is perforated for mounting the piezoelectric sounder. The piezoelectric sounding body can be mounted on only one side of the printed wiring board.

[0010]

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

1 to 3 show an electroacoustic transducer according to an embodiment of the present invention. 1 is an exploded perspective view, and FIG. 2 is X in FIG.
Assembly sectional view cut in the X direction, FIG. 3 is YY in FIG.
The sectional view cut | disconnected in the direction is shown.

A metal substrate 1 has a piezoelectric ceramic plate 2 bonded to its back surface to form a piezoelectric vibrating plate 3. Reference numeral 5 denotes an upper case, which is a groove 4 larger than the outer shape of the piezoelectric vibrating plate, a hole (sound emitting hole) 15 for radiating a predetermined sound, and a terminal 9, which will be described later.
Notches 16 and 17 for placing 12 (not shown)
Is formed. 7 is a lower case, 6 is a convex portion, 18,
Reference numeral 19 is a groove formed by cutting out a part of the convex portion of 6. 9, 12
Is a terminal formed of a thin metal substrate, and is provided with bent-back bent portions 11 and 14 as U-shaped bent portions 10 and 13. With the above component structure, the piezoelectric vibration plate 3 is supported by the concave groove 4 of the upper case 5 and is sandwiched between the convex portion 6 of the lower case 7. The U-shaped terminal is clamped and held on the outer peripheral side wall of the lower case 7 by the U-shaped bent portions 10 and 13 by the elastic force of the metal. After assembly, the bent-back portion 11 of the U-shaped terminal 9 is brought into contact with the piezoelectric ceramic plate with spring pressure, and the other U-shaped terminal 12 is repeatedly bent.
Makes contact with the metal substrate 1 with spring pressure. Upper case 1
Reference numeral 6 denotes a groove formed on the inner wall, which engages with the protrusion 8 of the lower case.

When the electroacoustic transducer of the present invention having the above-described structure is mounted, the portions of the U-shaped terminals 9 and 12 exposed from the outer peripheral side wall of the case serve as soldering portions to the application wiring board of the device. Can be mounted only on the front side of the applied wiring board.

Further, in this embodiment, the terminals 9 and 12 can be mounted in exactly the same shape, and the parts are standardized and shared.

[0015]

As described above, according to the present invention, a U-shaped terminal having a repeated bent portion is arranged between the upper case and the lower case, and a part of the surface is exposed from the outer circumference of the case, and It is used as a solder connection portion to a printed wiring board, and its effect will be described below.

(1) Since a piezoelectric sounding body is arranged on one side of a printed wiring board of a device and terminals such as soldering can be connected, high-density mounting can be realized.

(2) The printed wiring board of the device does not require the processing of the terminal insertion hole of the piezoelectric sounding body, which can reduce the processing cost of the printed wiring board and the piezoelectric sounding body can be arranged on the printed wiring board. Since the mounting accuracy is not restricted by the terminal insertion hole, automatic mounting becomes easy.

(3) By repeatedly bending the terminal, the terminal can have sufficient elasticity, and high reliability can be realized for contacting the piezoelectric diaphragm.

Although an example of a sounding body, that is, a speaker has been described in the embodiment, the same applies to other electroacoustic transducers using a piezoelectric element, such as a microphone for converting sound into an electric signal. It is applicable.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a sectional view of one embodiment of the present invention.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a sectional view of a conventional electroacoustic transducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal substrate 2 Piezoelectric ceramic plate 5 Upper case 7 Lower case 9 U-shaped terminal 11 Repeated bending part 12 U-shaped terminal 14 Repeated bending part

Claims (3)

[Claims] 1. A piezoelectric vibrating plate in which a piezoelectric ceramic substrate is attached to a metal substrate, an upper case that supports one end of one side of the metal plate, a lower case that mates with the upper case, and a thin metal plate. It has a pair of terminals formed in a square shape and one end of which is bent back and bent, and the terminals are sandwiched and held in the lower case by a U-shaped portion, and the piezoelectric vibration plate is held by the upper case. An electroacoustic transducer in which the lower case is fixed to the upper case while supporting the piezoelectric vibrating plate at the bent and bent portion of the terminal. 2. A portion of the pair of terminals, which is bent back and bent, presses the piezoelectric vibration plate, one terminal is a metal substrate, and the other terminal is an electrode portion on the piezoelectric ceramic substrate. Electro-acoustic transducer. 3. The electroacoustic transducer is a sounding body.
Alternatively, the electroacoustic transducer described in 2.