JPS6325839Y2 - - 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 diaphragm ring, 4 is a diaphragm (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), and 9 is an electrical impedance conversion element such as a field effect transistor (hereinafter referred to as FET).
It is. In this configuration, the gate terminal of the FET 9 is connected to the back electrode 6 by contact or spot welding, etc., and after insertion into the insulator 7, these parts are configured as one amplifier block via the substrate 8, and the vibrating membrane is connected. After inserting the diaphragm 4 and the spacer 5, which are given a certain tension by the ring 3, into the case 2, the amplifier block is inserted into the case 2 and fixed by caulking or the like, completing the assembly. Therefore, since amplifier blocks often rely on manual assembly and are difficult to assemble completely automatically, they are not suitable for mass production and there are limits to cost reduction.

In view of the above points, the present invention aims to provide an inexpensive electret condenser microphone suitable for mass production.

That is, the present invention provides an insertion section into which an electrical impedance conversion element is inserted in the center of the insulator into which the back electrode is press-fitted, and when a double-sided printed circuit board is inserted and fixed into the opening of the insertion section, the insertion section is inserted into the insertion section. The gate electrode of the inserted electrical impedance conversion element is press-connected to the back electrode, the output electrode and the ground electrode of the electric impedance conversion element are press-connected to the internal pattern of the double-sided printed circuit board, and the Through-holes are provided on the double-sided printed circuit board to connect the internal and external patterns, and there is no need to assemble the amplifier block by hand in advance; each component can be inserted into the case one after another.
Suitable for mass production and can be supplied at low cost.

Embodiments of the present invention will be described below based on the drawings. FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is an enlarged sectional view of the same main part. The same components as those shown in FIG. The explanation will be omitted. In the embodiment shown in FIGS. 2 and 3, the difference from the conventional structure is that a double-sided printed circuit board 10 is used as the substrate, and the output terminal 9a of the FET 9 and the ground terminal (not shown) are connected to the double-sided printed circuit board 10. 10, and further connected to the external pattern 10b via the through hole 11 of the double-sided printed circuit board 10 to form an external terminal, and each terminal of the FET 9 is connected by contact or the like. In this case, all the parts can be inserted by dropping them into the case 2, so there is no need to assemble the amplifier block as in the conventional case.
Fully automatic assembly becomes possible. In this case, air leak may occur from the through-hole 11 portion of the double-sided printed circuit board 10, resulting in low frequency deterioration, but in actual use, lead wires etc. are soldered, so there is no problem. Alternatively, it may be soldered in advance. Also, insulator 7 FET
If the FET 9 housing section is designed to prevent its position from shifting when the FET 9 is housed, the FET
9 can be reliably bonded to the back electrode 6 and the double-sided printed circuit board 10.

Figure 4 shows another embodiment, thus
Back air chamber 12 that interacts acoustically with the housing part of FET9
may be separated. In this case, there is no need to seal the through-hole 11 portion of the double-sided printed circuit board 10 by soldering.

As explained above, according to the electret condenser microphone according to the present invention, the FET inserted into the insertion part of the insulator has its gate terminal connected to the back electrode press-fitted into the insulator.
The ground electrode and output electrode of the amplifier block are securely connected to the double-sided printed circuit board that is inserted and fixed into the opening of the insertion section.This eliminates the need to assemble the amplifier block by hand in advance, and instead inserts each component into the case one by one. Since the assembly can be completely automated, it is suitable for mass production and can be manufactured at low cost. Furthermore, there is no need to solder the ground and output terminals of the electrical impedance converting element to the board, and from this point as well, costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional electret condenser microphone, Fig. 2 is a sectional view of an electret condenser microphone according to an embodiment of the present invention, Fig. 3 is an enlarged sectional view of the same main part, and Fig. 4 is a different electret condenser microphone. 1 is a cross-sectional view of an electret condenser microphone in an example. 2...Case, 9...Electric impedance conversion element, 9a...Output terminal, 10...Double-sided printed circuit board, 10a...Internal pattern, 10b...External pattern, 11...Through hole.

Claims (1)

[Scope of utility model registration request] An insertion part for inserting an electrical impedance conversion element is provided in the center of the insulator into which the back electrode is press-fitted,
When the double-sided printed circuit board is inserted and fixed into the opening of the insertion section, the gate electrode of the electrical impedance conversion element inserted into the insertion section is press-connected to the back electrode, and the output electrode of the electrical impedance conversion element is connected to the back electrode. and an electret condenser microphone, wherein the ground electrode is pressure-contacted to an internal pattern of the double-sided printed circuit board, and a through hole is provided in the double-sided printed circuit board to connect the internal pattern and the external pattern.