In-plane overtravel stops for mems microphone

Abstract

MEMS microphones and MEMS devices. In one embodiment, the MEMS microphone includes a membrane and a layer. The membrane is coupled to a support. The layer includes a backplate and an overtravel stop. The backplate is coupled to the support. The overtravel stop is coupled to the membrane and is physically separated from the backplate by a gap in a radial direction. The overtravel stop has a first end that is oriented proximal to the membrane and a second end that is oriented distal to the membrane. The second end flares outward to restrict movement of the membrane in the radial direction by contacting the backplate.

What is claimed is: 
     
         1 . A MEMS microphone comprising:
 a membrane coupled to a support; and   a layer including
 a backplate coupled to the support, and 
 an overtravel stop coupled to the membrane and physically separated from the backplate by a gap in a radial direction, the overtravel stop having
 a first end oriented proximal to the membrane, and 
 a second end oriented distal to the membrane and flaring outward to restrict movement of the membrane in the radial direction by contacting the backplate. 
 
   
     
     
         2 . The MEMS microphone of  claim 1 , wherein the second end of the overtravel stop has an arch-shaped stop on each side of the second end of the overtravel stop, the arch-shaped stop being perpendicular to the radial direction. 
     
     
         3 . The MEMS microphone of  claim 2 , wherein the two arch-shaped stops contact the backplate when the membrane has reached a maximum deflection. 
     
     
         4 . The MEMS microphone of  claim 1 , wherein the first end of the overtravel stop is coupled to the membrane. 
     
     
         5 . The MEMS microphone of  claim 1 , wherein the overtravel stop is located along a perimeter of the membrane. 
     
     
         6 . The MEMS microphone of  claim 1 , wherein the support includes an oxide anchor. 
     
     
         7 . The MEMS microphone of  claim 1 , wherein the second end of the overtravel stop flares outward to restrict movement of the membrane in an inward radial direction by contacting the backplate. 
     
     
         8 . The MEMS microphone of  claim 1 , wherein the membrane is coupled to the support via a spring. 
     
     
         9 . The MEMS microphone of  claim 8 , wherein the spring is formed out of the membrane. 
     
     
         10 . The MEMS microphone of  claim 1 , wherein the overtravel stop is released from the backplate. 
     
     
         11 . A MEMS device comprising:
 a movable structure coupled to a support; and   a layer including
 a rigid structure coupled to the support, and 
 an overtravel stop coupled to the movable structure and physically separated from the rigid structure by a gap in a radial direction, the overtravel stop having a first end oriented proximal to the movable structure, and
 a second end oriented distal to the movable structure and flaring outward to restrict movement of the movable structure in the radial direction by contacting the rigid structure. 
 
   
     
     
         12 . The MEMS device of  claim 11 , wherein the second end of the overtravel stop has an arch-shaped stop on each side of the second end of the overtravel stop, the arch-shaped stop being perpendicular to the radial direction. 
     
     
         13 . The MEMS device of  claim 12 , wherein the arch-shaped stops contact the rigid structure when the movable structure has reached a maximum deflection. 
     
     
         14 . The MEMS device of  claim 11 , wherein the first end of the overtravel stop is coupled to the movable structure. 
     
     
         15 . The MEMS device of  claim 11 , wherein the overtravel stop is located along a perimeter of the movable structure. 
     
     
         16 . The MEMS device of  claim 11 , wherein the support includes an oxide anchor. 
     
     
         17 . The MEMS device of  claim 11 , wherein the second end of the overtravel stop flares outward to restrict movement of the movable structure in an inward radial direction by contacting the rigid structure. 
     
     
         18 . The MEMS device of  claim 11 , wherein the movable structure is coupled to the support via a spring. 
     
     
         19 . The MEMS device of  claim 18 , wherein the spring is formed out of the movable structure. 
     
     
         20 . The MEMS device of  claim 11 , wherein the overtravel stop is released from the rigid structure.