| 摘要 |
PURPOSE:To make the production process easy by forming the vessel for sealing the chip having the gate terminal of the FET for microphone in one body with the microphone body itself, providing an air chamber on the adjacent part of the outside circumference of the back plate, and shortening the coupling leak hole for coupling the air chamber and the open air. CONSTITUTION:The gate terminal of the FET for microphone is made to use it as a back plate of an electret capacitor type microphone, as well, by the back plate and gate terminal 2, and the vessel for sealing the chip having the gate terminal is formed in one body with the microphone body itself as a microphone vessel and FET vessel 1. Length of the leak hole 8 for coupling the air chamber 7 and the open air is shortened by providing the air chamber on the adjacent part of the outside circumference of this back plate and gate terminal 2, so that it can be coupled easily, and therefore the production process can be simplified. |
