| 摘要 |
PROBLEM TO BE SOLVED: To provide a unidirectional MEMS microphone suitable for application to a production process under heating atmosphere such as reflow soldering.SOLUTION: A MEMS acoustic chip and an acoustic resistor are housed in a casing, and a first sound hole and a second sound hole are formed in the casing. The MEMS acoustic chip is fixed to the casing, and a diaphragm electrode for converting a sound into an electric signal is formed therein. In the acoustic resistor, the opening edge of a depression is fixed to the casing, and communication sound holes communicating with the inside of the casing is provided in the back part of the depression. The first sound hole communicates with the inside of the MEMS acoustic chip from the outside of the casing. The second sound hole communicates with the inside of the depression from the outside of the casing. The distance from the second sound hole to the communication sound hole of the acoustic resistor is set equal to or longer than the distance from the first sound hole to the diaphragm electrode of the MEMS acoustic chip.SELECTED DRAWING: Figure 1 |
