A novel capacitive type miniature microphone with a flexure hinge diaphragm

Abstract

This paper presents a novel, highly sensitive condenser microphone with a flexure hinge diaphragm. We used the finiteelement analysis (FEA) to evaluate the mechanical and acoustic performance of the condenser microphone with a hinge diaphragm. And we fabricated the miniature condenser microphones with area of 1.5 mm x 1.5 mm. From the simulation and measurement results, we confirmed that the maximum displacements at the center of flexure hinge diaphragms are several hundred times, compared with flat diaphragms. Moreover, the miniature microphones have obtained -3 dB bandwidth of nearly 20 kHz by proper design of the flexure hinge diaphragms.