JPH018080Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electret condenser microphone.

A conventional electret condenser microphone will be explained with reference to FIG. 1 is a face cloth, 2 is a case, 3 is a membrane ring, 4 is a vibration membrane (electret film), 5 is a spacer, 6 is a back electrode,
7 is an insulator, 8 is a printed circuit board (hereinafter referred to as the board), 9 is an electrical impedance conversion element such as a field effect transistor (hereinafter referred to as FET),
9a is the gate terminal of the FET9. In this configuration, when the gate terminal 9a of the FET 9 is connected to the back electrode 6 by contact, a recess 7a is provided in a part of the insulator 7 where the back electrode 6 is inserted, as shown in FIG. By inserting the gate terminal 9a into the recess 7a and press-fitting the back electrode 6 into the insulator 7, the gate terminal 9a is inserted between the back electrode 6 and the insulator 7.
It was held in place by sandwiching it in place. However, in such a configuration, the groove depth of the recess 7a of the insulator 7
It was necessary to pay attention to the dimensional tolerance of the thickness of the gate terminal 9a of the FET 9.

In view of the above points, it is an object of the present invention to provide an electret condenser microphone that can easily and reliably connect the gate terminal of the electrical impedance conversion element to the back electrode.

In order to achieve the above object, the present invention provides an insulator having a press-fitting part for a back electrode and a housing part for an electrical impedance converting element near the upper part of the electrical impedance converting element housing part (back electrode press-fit side) or It is fixed to the inner wall near the lower part (on the printed circuit board side), is curved toward the back electrode side and protrudes into the housing part, and the curved part is the gate terminal of the electric impedance conversion element or the electric impedance conversion element. A thin part is integrally provided on the end of the element opposite to the gate terminal to be brought into elastic pressure contact and to bring the gate terminal into pressure contact with the back electrode.

Embodiments of the present invention will be described below based on the drawings.

FIG. 3A is a sectional view of a main part showing an embodiment of the present invention, and FIG. 3B is a sectional view taken along line B-B in FIG. The same reference numerals are given and the explanation thereof will be omitted. Third
In the embodiment shown in Figures A and B, the difference from the conventional structure is that a thin part 10a with a thickness of 1 mm or less is fixed to the inner wall of the FET 9 accommodating part of the insulator 7 at a position near the back electrode 6, and the back It is curved toward the electrode side and protrudes into the housing portion of the FET 9, and the gate terminal 9a of the FET 9 is inserted between the thin portion 10a and the back electrode 6.
This is because the gate terminal 9a is brought into pressure contact with the back electrode 6 due to the elasticity of the curved portion of the thin portion 10a.

According to the above configuration, the gate terminal 9a of the FET 9 is brought into pressure contact with the back electrode 6 by utilizing the springiness of the curved part of the thin part 10a, so that dimensional tolerances of each part can be absorbed, and the back electrode 6 etc. No tilting occurs.

In addition, even if various parts contract or expand due to temperature changes, the elasticity of the ultra-thin part 10a can sufficiently absorb the contraction or expansion.
High stability and reliability can be obtained even against temperature changes.

FIGS. 4A and 4B show another embodiment, in which the FET 9 may be inserted from the back electrode 6 side of the insulator 7. In this case, the insulator 7
A thin wall portion 10b is fixed to a position near the substrate 8 on the inner wall of the FET 9 accommodating portion, and is curved toward the back electrode side.
This thin part 10 is protruded into the housing part of the FET 9.
The elasticity of the curved portion b pushes up the lower surface of the mold on the side opposite to the gate terminal 9a of the FET 9, bringing the gate terminal 9a and the back electrode 6 into contact at point A. Even in this configuration, the same effects as the embodiments shown in FIGS. 3A and 3B can be obtained.

In the above embodiment, an example in which the FET 9 accommodating portion is provided at the center of the insulator 7 has been described, but the FET 9 accommodating portion may be provided at the outer periphery of the insulator 7.

Further, in the above embodiment, an example in which the FET 9 is installed vertically has been described, but the FET 9 may also be installed horizontally, and in this case, an even thinner electret condenser microphone can be provided.

As explained above, according to the electret condenser microphone according to the present invention, the gate terminal of the electrical impedance conversion element and the back electrode can be easily and reliably coupled.
It has a high degree of stability against temperature changes and can achieve high reliability.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional electret condenser microphone, Fig. 2 (a) is an enlarged sectional view of the same main part, and Fig. 2 (b) is a sectional view taken along line A-A in (a).
Figure 3A is a sectional view of the main parts of an electret condenser microphone according to one embodiment of the present invention, Figure 3B is a sectional view taken along the line B-B in Figure 4A, and Figure 4A is a cross-sectional view of an electret condenser microphone in another embodiment. A cross-sectional view of the main parts of the condenser microphone, and FIG. 6...Back electrode, 7...Insulator, 8...Substrate, 9
...electrical impedance conversion element, 9a...gate terminal, 10a, 10b...thin portion.

Claims (1)

[Scope of utility model registration request] An insulator having a press-fitting part for the back electrode and a housing part for the electric impedance conversion element is placed near the top (back electrode press-fit side) or bottom (printed circuit board side) of the electric impedance conversion element housing part.
fixed to the inner wall of the back electrode, curved toward the back electrode side, and protruded into the accommodating portion, the curved portion being opposite to the gate terminal of the electrical impedance conversion element or the gate terminal of the electrical impedance conversion element. An electret condenser microphone integrally provided with a thin wall portion that is elastically pressed into contact with a side end portion to bring the gate terminal into pressure contact with the back electrode.