Patent ID: 6870939
Filing Date: 2005-03-22
Classification: H04R

Abstract:
1. A structure of the silicon-based electret condenser microphone which comprise of: (1) flat-type or corrugated-type composite diaphragm-chip, which comprises a first substrate; a flat-type or corrugated-type diaphragm, formed on the bottom of the first substrate; a first Nitride-Silicon layer, formed on the top of the first substrate; a concave slot, formed on the first substrate and the first Nitride-Silicon layer; a first electrode layer, formed on the first Nitride-Silicon layer and the top of the concave slot; a electret layer, formed on the bottom of the diaphragm; a spacer, formed on the both terminal zones of the electret bottom; (2) back-plate chip, which comprises a second substrate; a MOSFET, formed on the one side of the second substrate top; two deposit layers, formed on the top and the bottom surfaces of the second substrate; a cannelure, formed on the top-face of the second substrate and the one side of the MOSFET; several Perforated holes, formed on a suitable area of the second substrate; a back-chamber, formed on the bottom-face of the second substrate perforated holes and is an up-toward concave slot; a second electrode layer, formed on the top-face of the back-plate chip; a pair of conductive pin hole, formed on the top-face the back-plate chip; (3) a shell, which is used to pack the composite diaphragm chip and the back-plate chip together to form a Silicon-based electret condenser microphone.