JPS60260300A - Electret condenser microphone - Google Patents

Abstract

PURPOSE:To eliminate a defect in sensitivity and frequency characteristic, etc. by providing a concaved part to a face opposite to a diaphragm of a fixed electrode forming a capacitor with the diaphragm and a projection at the opposite side and applying spot welding of the lead wire to the projection. CONSTITUTION:The projection 6b is provided to a part to be connected with a lead wire 8a of the fixed electrode and the concaved part 6a is provided to the opposite face. The fixed electrode 14 and the moving electrode 13 are used to apply spot welding to the projection 6b of the electrode 6 to the lead 8a. In such a case, a projection is produced to the concaved part 6a provided at the opposite side of the projection 6b. Even when a projection is produced, the diameter and depth of the projection 6a are set properly so as not to give effect on other parts. Then the projection is contacted to the diaphragm 4 to give no adverse effect on the sensitivity and frequency characteristic, it is not required to remove the projection at each case and the electret condenser microphone low in cost and excellent in performance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a built-in electret condenser microphone built into a tape recorder or the like.

Structure of a conventional example and its problems FIG. 1 shows a sectional view of a conventional electret condenser microphone. The configuration of this conventional example will be explained below with reference to FIG. 1.

In Figure 1, 1 is an acoustic resistance surface cloth, 2 is a sound hole 2a on the top surface.
A cylindrical metal case 3 has a vibrating membrane 4 made of an electret material with metal vapor deposited on one side, and a metal ring 6 has a gap between the metal fixed electrode 6 and the vibrating membrane 40. an insulating spacer 7 for forming a gap to form a capacitor between e and the diaphragm 4; 7 is an opening for fixing the fixed electrode 6; The bottom cylindrical insulator, 8 is a field effect transistor (hereinafter referred to as F) that electrically converts impedance.
ET), the input side lead wire 8a is spot welded to the fixed electrode 6, and the output side lead 4isb is soldered to the copper foil pattern 9a via the printed circuit board 9 provided in the opening of the metal case 2. has been done.

By the way, in the above conventional example, the FET 8 is connected to the fixed electrode 6.
When connecting the input side lead wire 8a, both are spot welded, and therefore, as shown in FIG. There was a problem in that this came into contact with the vibrating membrane 4 and adversely affected the sensitivity, frequency characteristics, etc.

For this reason, conventionally, when sispot welding is performed, the protrusions are ground down with a grindstone, etc., to avoid adversely affecting the sensitivity 1 frequency characteristics, etc., but even in this case, it is necessary to completely remove the protrusions. is almost impossible, and
The overall cost is high because it requires separate work to remove the protrusions mentioned above.

It was not necessarily superior in terms of performance.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the above-mentioned conventional examples, and aims to provide an excellent electret condenser microphone that has a simple structure and does not cause problems in sensitivity and single frequency characteristics.

Structure of the Invention The present invention is configured such that a convex portion and a concave portion are formed in advance at a portion of a fixed electrode to which a lead wire is connected, and a concave portion is formed on the opposite surface, and the lead wire is spot-welded to the convex portion. .

DESCRIPTION OF THE EMBODIMENTS FIG. 3 is a cross-sectional view of an embodiment of the electret condenser microphone of the present invention. In the figure, parts designated by the same numbers as in FIG. 1 indicate the same parts as in FIG. 1. 4, the difference from FIG. 1 is that the lead wire 8 of the fixed electrode 6
Convex part 6b on the part connecting a, and four parts 6a on the opposite side
The input side lead 8a of the FET 8 is spot welded to this protrusion 6b.

FIG. 6 shows a lead wire 81 connected to the fixed electrode 6 in the above embodiment.
It is an explanatory view when spot welding L.

When the fixed electrode 14 and the movable electrode 13 are used to spot-weld the lead wire 8a to the protrusion 6b of the fixed electrode 6 as shown in FIG. As shown in FIG. 6, a protrusion 12 is generated in the recess 6a, but even if the protrusion 12 is generated, it will remain within the recess 6a, so by setting the diameter and depth of the recess 6a appropriately, 11. There is no need to scrape off the protrusion 12 caused by spot welding, and there is no possibility that it will come into contact with the vibrating membrane 4. Note that the recess 6a provided in the fixed electrode 6 may affect the value of the capacitor formed between the fixed electrode 6 and the vibrating membrane 4, but the diameter of the recess 6a The depth may be about φ1 word and the depth may be about o, 1 wb at most, and therefore the recess ea almost never affects the value of the capacitor.

In the above example, an electret condenser microphone with a built-in FICT8 was explained, but an FET
It goes without saying that even devices that do not have a built-in 8 can be constructed in the same way.

Effects of the Invention As is clear from the above-mentioned embodiments, the present invention provides a convex portion on the part of the fixed electrode to which the lead wire is connected, and four portions on the opposite surface, and the lead wire is spot-welded to the convex portion. Even if a protrusion occurs during spot welding, it will be present in the recess formed in the fixed electrode 6, so there is no need to remove the protrusion each time, and it is inexpensive and has good performance. This has the advantage that an excellent electret condenser microphone can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of a conventional electret condenser microphone, Fig. 2 is a perspective view of the same essential parts, Fig. 3 is a cross-sectional side view of an electret condenser microphone according to an embodiment of the present invention, and Fig. 4 is a fixed electrode FIG. 5 is a perspective view of a main part of the above-mentioned embodiment. 4... Vibration membrane, 6... Fixed electrode, 8...
...FET. 8a...Input side lead wire. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] An electret condenser microphone comprising a metal fixed electrode that forms a capacitor with a vibrating membrane, and a convex part provided on the opposite side of the vibrating membrane in four parts, and a lead wire spot-welded to the convex part.