Thin film electret electrostatic microphone and its production manner

摘要

PROBLEM TO BE SOLVED: To attain further performance improvement without generating individual difference in performance caused by dispersions in the thickness of an electret layer or the like. ;SOLUTION: This back electret type thin film electret capacitor microphone has thin film forming processes A-D for directly forming a thin film 120 on the surface of a back plate 4 from fine particles of high-molecular FEP and a polarizing process E or F for performing polarizing processing to the thin film 120. The thin film forming process has a process A for applying an organic solvent 100 for dispersing fine particles of high-molecular FEP onto the back plate 4 through a spin-on-coat method, a process B for removing only organic solvent 110 by heating the back plate 4 to which the organic solvent 100 is applied, and a process D for forming thin film of high-molecular FEP by heating the back plate 4, from which only the organic solvent 100 is removed, at a much higher temperature. The polarizing process is performed by cooling the back plate 4 with a solution 200 such as water after the thin film forming process.;COPYRIGHT: (C)1999,JPO