Condenser MEMS Microphone

— The market for MEMS microphones is growing every year. The aggregate average annual growth rate is 11.7%. This is due to the increase in devices using voice control, the increase in the number of microphones in smartphones, and the increasing role of MEMS microphones in the Internet of Things. A MEMS microphone consists of a MEMS element for converting acoustic pressure, a preamplification chip, a board with an acoustic inlet, and a cover. The MEMS conversion element is a variable capacitor with polysilicon plates. The main parameters of MEMS microphones are the signal-to-noise (S/N) ratio, non-linear distortion coefficient, and non-uniformity of the amplitude-frequency characteristics. When developing a MEMS microphone, computer simulation is used in the ANSYS software package. Using the ANSYS Mechanical program, the design is calculated and optimized to achieve the necessary sensitivity parameters of the MEMS conversion element. Using electrostatic analysis, the CV characteristics are calculated to determine the active capacitance and collapse voltage of MEMS-CE membranes. The influence of the housing dimensions, position, size and number of acoustic holes, the sizes above the membrane and under membrane volumes of the microphone frequency response is calculated in order to determine the effect of the housing parameters on the MEMS microphone’s characteristics. An experimental prototype of the first domestic MEMS microphone is developed and manufactured at the NPK Technological Center. New designs are being actively designed to improve the technical characteristics of MEMS microphones.