Acoustic-signal/electric-signal converting device and method for fabricating the same

PURPOSE: An acoustic signal to electric signal converting device and a manufacturing method thereof are provided to improve a vibrating function by flexibly operating the thinning process of a vibration plate. CONSTITUTION: A back chamber(BC) is formed in a substrate(101). A vibration plate(102) is formed on the substrate in order to cover up the back chamber. A variable electrode(103) is formed on the suspending area of the vibration plate corresponding to the back chamber. A cover plate(105) defines an acoustic hole and an air gap. The cover plate is formed in the vibration plate in order to cover up the variable electrode. The cover plate operates as the fixed electrode corresponding to the variable electrode. The cover plate is formed by an electroplating process utilizing a polymer based sacrificial layer.