United States Patent and Trademark Office has granted MEMS company Sand 9 a patent based on the use of piezoelectric MEMS for a wafer-level, chip-scale packaged (WLCSP) microphone.
piezoelectric MEMS solves the sticktion problem of condenser mic. piezoelectric MEMS microphone also offers higher thermal-mechanical noise performance. piezoelectric MEMS does not require DC biasing resulting in lesser power consumption.
Sand 9 says piezoelectric MEMS microphones offer high electromechanical coupling compared with electrostatic transduction, enabling improved SNR with lower power consumption. Piezoelectric MEMS can be packaged in WLCSP with through-silicon-vias (TSVs) to support both top and bottom port configurations with matched performance in the smallest package size, according to Sands 9.