An integrated printed circuit board (PCB) microphone

An electret microphone has been implemented into a printed circuit board. Due to novel construction the printed circuit board serves as the microphone backplate. Furthermore, other features of printed circuit beard manufacturing technology are applied to minimize the number of components of the microphone. This results in a microphone that can be manufactured with the assembly of other electronic components during the manufacturing process. As a result a complete manufacturing process has been developed. To analyze the manufacturing process and the acoustical performance of the so-called PCB-microphone, the acoustics have been modeled, and backplate surface roughness, air gap thickness, electret charge, and overall sensitivity have been measured from prototypes. (C) 2000 Acoustical Society of America.