JPS5813677Y2 - electrostatic microphone - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electrostatic microphone incorporating an impedance conversion element, and more particularly to an electrostatic microphone with an improved mounting structure for the output terminal of the impedance conversion element.

In general, electrostatic type microphones such as electret condenser microphones have a high twin-pedance as a single electroacoustic transducer, so they are field effect transistors (hereinafter simply referred to as FETs).

Conventionally, a structure as shown in FIGS. 1 and 2, in which an impedance conversion element such as ) is housed in a capsule together with the electroacoustic conversion element described above, has been used.

In the conventional example shown in FIG. 1, a diaphragm ring 2 with a diaphragm 1 stretched thereon is placed on a back plate 4 via an insulating spacer 3, and the diaphragm 1 and the back plate 4, which are arranged opposite to each other, are kept static. It constitutes an electric-type electroacoustic transducer element.

Further, the FET 5 as an impedance conversion element has its gate terminal 5a disposed on the back plate 4, and its drain terminal 5b and source terminal 5C disposed on each ribbon-shaped terminal piece 7a, 7b disposed on the terminal plate 6. Each solder is electrically connected by etc.

A back plate 4 is placed on the terminal plate 6 provided with the terminal pieces 7a and 7b via a spacer 8, and these are housed in a capsule 9.

In the conventional example of such a structure, the FET 5 is placed in a space between the back plate 4 and the terminal plate 6, which are arranged through the spacer 8, without being mechanically fixed. Each lead terminal such as the terminal 5a, the drain terminal +5b, and the source terminal 5C is easily disconnected due to mechanical vibration or impact, and a large number of man-hours are required to electrically connect each lead terminal within the capsule 9. There are drawbacks.

Furthermore, the ribbon-shaped terminal pieces 7a and 7b provided on the terminal board 6 do not have sufficient mechanical strength and are easily damaged during the assembly process, such as by breaking.

In addition, in the conventional example shown in FIG. 2, a FET chip 15 as an impedance conversion element and terminal pieces 17a, 17b, 17c to which bonding wires 15a, 15b, 15c are connected are embedded and molded. A back plate 14 is formed on the surface of the holder 100 by vacuum deposition or the like.

In a conventional example of such a structure, the FET chip 15
and each terminal piece 17a, 17b.

There is a drawback that the relatively long bonding wires 15a, 15b, and 15c interposed between the bonding wire 17c and the bonding wire 17c are easily cut and broken during the manufacturing process such as molding.

Therefore, in view of the shortcomings of the conventional examples as described above, the present invention aims to simplify the mounting structure of the output terminal of the impedance conversion element and improve the mechanical strength, thereby creating an electrostatic microphone that is low-cost and can be used in practical use. This is what we are trying to provide.

Hereinafter, the present invention will be described in detail with reference to the drawings showing one embodiment.

First, in the electrostatic microphone according to the present invention, as shown in FIGS. 3 to 3C, a wiring pattern 22 formed on a long rectangular printed wiring board 21
Lead terminals 23a, 23b, 2 of FET 23 as impedance conversion elements are connected to a, 22b, 22c.
3c is connected and fixed by soldering or the like.

Here, FIGS. 3A to 3C represent each lead terminal 23a of the FET 23.

23b and 23c are attached to each printed wiring board 21 according to the arrangement state, and on each side of these, three wiring pattern y22a,
22b, 22c are formed along the longitudinal direction, and each wiring pattern 22a, 22b.

Each lead 23a, 23b23 of the above FET23 is connected to 22c.
c is soldered and fixed.

Note that each wiring pattern 22a, 22b, 2 of the printed circuit board 21 on each side shown in FIG.
2c is each lead terminal 23a, 23b of the FET 23.

23c are connected in the same way, and in the case of the example shown in FIG. A gate portion 23b of the FET 23 is connected to the gate portion 23b of the FET 23.

Next, the printed wiring board 21 on which the FET 23 as the impedance element is attached is mounted perpendicularly to the back plate 24 forming the electroacoustic transducer, as shown in FIG. 4 and FIG. 4B. A gate terminal 23a of the FET 23 disposed on the rear surface 24a side of the FET 24 is electrically connected to the backplate 24.

That is, the printed circuit board 21 on which the FET 23 is attached as shown in FIGS. 3A to 3C is connected to the wiring pattern 22a to which the gate terminal 23a is soldered and fixed, as shown in FIG. Spring contact piece 25 attached to the end
is in pressure contact with the back surface 24a of the back plate 24, or as shown in FIG. Due to the structure such as being held between a pair of spring contact pieces 25a and 25b,
It is disposed upright on the back surface 24a side of the back plate 24.

In FIG. 4 and FIG. 4B, 26 is a diaphragm, 27 is a diaphragm ring, and 28 is an insulating spacer. 24 to form an electroacoustic transducer element.

The printed wiring board 21, which is disposed upright on the back surface 24a side of the back plate 24 of the electroacoustic transducer as described above, is connected to the fifth
It is housed in a capsule 29 as shown in FIGS.

Here, one end in the longitudinal direction of the printed wiring board 21 housed in the capsule 29 protrudes to the outside from the bottom cover side of the capsule 4, and the wiring patterns 22b and 22c formed on this protruding portion are exposed to the outside. Output terminal 30a,
30b.

In addition, in FIG. 5 to FIG. 5C, 31 is an opening for applying sound pressure due to acoustic input to the diaphragm 26 forming an electroacoustic transducer.

Further, 32 is a ground terminal connected to the capsule 29, etc., and this ground terminal 32 may be formed on the printed wiring board 21 as in the example shown in FIG. 5C.

In this way, the printed wiring board 21 on which the FET 23 is attached is disposed upright on the rear surface 24a side of the back plate 24, and the printed wiring board 21 is housed in the capsule 29 along the axial direction, thereby achieving the above-mentioned One end side of the printed wiring board 21 is made to protrude outside from the capsule 29, and each wiring pattern y22b, 22c is connected to an output terminal 30a.
, 30b, and each wiring pattern y22b, 22cf: used output terminal 30a.
.

Since 30b is formed on the printed wiring board 21, it has sufficient mechanical strength.

As is clear from the description of the embodiments described above, in the electrostatic type micron according to the present invention, the electroacoustic transducer is disposed upright on the back surface of the back plate of the electroacoustic transducer housed in the capsule, with one end protruding outside the capsule. a printed circuit board, in which two wiring patterns extending from one end of the printed circuit board and one wiring pattern extending from the other end of the printed circuit board are adjacent to each other; An impedance conversion element is arranged at a position, and each output terminal C of the impedance conversion element is connected to each of the wiring patterns, and the wiring pattern of the above-mentioned strip is connected to the other end of the printed circuit board via a spring contact piece. By being detachably connected to the back surface of the back plate and provided with two wiring patterns on one end side of the printed circuit board protruding outside the capsule as external connection terminals, the impedance conversion element can be attached electrically. It can be carried out reliably and easily physically and mechanically, and by reducing the number of parts and simplifying the manufacturing process, it can be provided as a practical product at a low price, and the intended purpose can be fully achieved.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional side views showing the structure of each conventional example of an electrostatic microphone. 3A to 3C are plan views showing each side of the mounting structure for the impedance conversion element in the electrostatic microphone according to the present invention. FIG. 4 and FIG. 4B are side views showing each side of the arrangement relationship between the printed wiring board to which the impedance conversion element is attached and the back plate. FIGS. 5A to 5C are external perspective views showing a state in which an electroacoustic transducer, an impedance transducer, and a printed wiring board are housed in a capsule. 21...Printed wiring board, 22a, 22b. 22c...Wiring pattern, 23...F
ET impedance conversion element, 23a, 23b, 2
3c=Each lead terminal of FET, 24...back plate, 24a...back side of back plate,
25, 25a. 25b... Spring contact piece, 26... Diaphragm, 27... Diaphragm ring, 28...
...Insulating spacer, 29...Capsule,
30a, 30b... External output terminals.

Claims (1)

[Scope of utility model registration request] It has a printed circuit board that stands upright on the back surface of the back plate of the electroacoustic transducer housed in the capsule and has one end protruding from the outside of the capsule. An impedance conversion element is placed in close proximity to the two wiring patterns and one wiring pattern extending from the other end of the printed circuit board, and the above and wiring are connected to each output terminal C' of the impedance conversion element. a printed circuit board that is connected to the pattern and that the wiring pattern of the stripes is removably connected to the back surface of the back plate on the other end side of the printed circuit board via a spring contact piece, and that is projected to the outside of the capsule; An electrostatic microphone characterized by having two wiring patterns on one end of the microphone as external connection terminals.