The present invention relates to an electret condenser microphone for preventing a soldering failure and inclination in the mounting of the microphone.
In the electret condenser microphone of the aforementioned conventional art, the terminal electrode patterns 11 outside the microphone are soldered to the terminals of a mounting substrate (not shown) in a soldering process performed in a reflow chamber. In this case, as described in Patent literatures 1 and 2, in order to perform smooth soldering in the reflow chamber, prevent a soldering failure caused by a short circuit or the like, or reduce the influence of heat on the curled portion, the soldering process in the reflow chamber is performed with the terminal electrode patterns 11 formed on the substrate 12 protruding higher than the top of the curled portion 13 of the capsule 2.
However, the terminal electrode patterns 11 on the substrate 12 vary in thickness even when plating is controlled. Moreover, the components stacked in the capsule 2 vary in thickness and the variations of the thickness are accumulated, and the amount of protrusion of the curled portion 13 varies depending upon the machining accuracy of the curled portion 13. As a result, the amount of protrusion of the terminal electrode patterns 11 is not stabilized relative to the curled portion 13, causing a soldering failure in the reflow chamber or a wrong position (inclination) of the microphone on the mounting substrate in the stage of the mounting of the microphone.
The present invention is designed to solve the above problem and has as its object the provision of an electret condenser microphone for preventing a soldering failure in a reflow chamber or a wrong position of the microphone on a mounting substrate in the stage of the mounting of the microphone.
In order to attain the above object, the present invention is configured as follows: in an electret condenser microphone, a substrate and components stacked on the substrate are fixed inside a capsule shaped like a cylinder thereof, the electret condenser microphone comprising the substrate having terminal electrode patterns, a top plate having sound holes, and the capsule having an inner flange portion stretching inward and a curled portion bent inward, in which the substrate is positioned at the inner flange, the terminal electrode patterns protrude outside the inner flange portion, and the top plate is positioned at the curled portion.
The inner flange portion and the curled portion may be opposed to each other on both ends of the capsule or the top plate may be disposed on the top of the components stacked on the substrate.
Further, the curled portion may be formed by crimping the end of the capsule and the top plate may be in contact with the curled portion.
According to the present invention, the substrate is positioned at the inner flange portion of the capsule and the terminal electrode patterns are protruded relative to the inner flange portion having a determined thickness. Thus it is possible to, unlike the conventional art, positively protrude the terminal electrode patterns with ease regardless of the accumulation of variations in thickness of the components and the machining accuracy of the curled portion, thereby preventing a soldering failure in a reflow chamber or a wrong position of a microphone on a mounting substrate in the stage of the mounting of the microphone.
Referring to
Above the opposite side of the substrate 12 from the side where the ground electrode pattern 14 is formed, a gate ring 8, a rear electrode holder 7, rear electrodes 6, a spacer 5, a diaphragm 4, and a diaphragm ring 3 are sequentially stacked. On the diaphragm ring 3, a top plate 30 including sound holes 31 is placed. The top plate 30 is made of, for example, the same metallic material and has the same thickness as the capsule 2. Further, the top plate 30 is crimped from the above (in other words, from the outside of the electret condenser microphone) by a curled portion 13 which is formed by bending inward the end of the capsule 2 (the opposite end from the inner flange portion 21), so that the substrate 12 and the components are fixed in the capsule 2.
As described above, according to the microphone of the present embodiment, the curled portion 13 is provided on the top plate 30 including the sound holes 31 as shown in
With this configuration, the substrate 12 is directly placed on the inner flange portion 21. Additionally, since the thickness of the inner flange portion 21 is also determined by stamping or the like, unlike the conventional art, even when the terminal electrode patterns 11 formed by plating on the substrate 12 vary in thickness, the amount of protrusion of the terminal electrode patterns 11 relative to the inner flange portion 21 is stabilized regardless of the accumulated error of the stacked components and the height —of the curled portion formed by crimping, thereby positively obtaining a proper amount of protrusion with ease. As a result, it is possible to avoid a soldering failure in a reflow chamber or a wrong position of the microphone on the mounting substrate in the stage of the mounting of the microphone. Further, it is possible to reduce the amount of protrusion of the terminal electrode patterns 11 and also reduce the amount and time of plating of the terminal electrode patterns 11, thereby reducing the manufacturing cost.
Although the aforementioned examples of
Although the foregoing embodiments describe that the capsule 2 is made of metal, the material of the capsule is not limited to metal. For example, the capsule 2 may be made of synthetic resin and made conductive by performing plating or the like on the inner wall surface of the capsule 2.
Number | Date | Country | Kind |
---|---|---|---|
2005-121051 | Apr 2005 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2006/007668 | 4/11/2006 | WO | 00 | 8/21/2007 |