MEMS Acoustic Sensor Diaphragm Recesses for Higher Capacitance

The diaphragm is divided into multiple combining parts (first combining part, second combining part, etc.) that can independently reciprocate. Each combining part forms its own capacitor with the back plate, effectively segmenting the capacitance generation function across multiple elements. This segmentation increases the total capacitor value and capacitor change while maintaining the signal-to-noise ratio benefits of the comb teeth structure.

The combining parts extend in the thickness direction (vertical dimension) of the diaphragm, creating capacitors that utilize the third dimension for charge distribution. This dimensional extension increases the effective capacitor area without increasing the planar footprint, thereby increasing capacitor value and change while preserving the original sensor's signal-to-noise ratio performance.

The diaphragm is segmented into multiple independent combining parts that can vibrate autonomously. This segmentation maintains the elasticity and vibration amplitude of each individual part while collectively providing a larger total capacitor area. Each combining part's smaller size preserves its vibrational characteristics, avoiding the amplitude reduction that would occur with a single large diaphragm.

The combining parts utilize the thickness direction to increase capacitor area rather than expanding the planar dimensions of the diaphragm. This vertical extension increases capacitor value without increasing the diaphragm's lateral size, thereby preserving the vibration amplitude and elasticity of the original diaphragm structure.