Mems device having a rugged package and fabrication process thereof

Abstract

A MEMS device formed by a substrate, having a surface; a MEMS structure arranged on the surface; a first coating region having a first Young's modulus, surrounding the MEMS structure at the top and at the sides and in contact with the surface of the substrate; and a second coating region having a second Young's modulus, surrounding the first coating region at the top and at the sides and in contact with the surface of the substrate. The first Young's modulus is higher than the second Young's modulus.

1 . A MEMS device, comprising:
 a substrate having a surface;   a MEMS structure arranged on the surface;   a first coating region having a first Young's modulus, the first coating region on the surface of the substrate and covering the MEMS structure; and   a second coating region having a second Young's modulus, the second coating region covering the first coating region,   wherein the first Young's modulus is higher than the second Young's modulus.   
     
     
         2 . The device according to  claim 1 , wherein the first Young's modulus is between 20 GPa and 30 GPa, and the second Young's modulus is between 100 MPa and 5 GPa. 
     
     
         3 . The device according to  claim 1 , wherein the first coating region comprises a polymeric resin. 
     
     
         4 . The device according to  claim 1 , wherein the second coating region comprises a polymeric rubber. 
     
     
         5 . The device according to  claim 1 , wherein the MEMS structure is electrically coupled to the substrate. 
     
     
         6 . The device according to  claim 1 , wherein the MEMS structure comprises:
 an ASIC die arranged on the surface of the substrate; and   a MEMS sensor die arranged on the ASIC die and electrically coupled to the ASIC die.   
     
     
         7 . A process comprising:
 coupling a MEMS structure to a surface of a substrate;   forming a first coating region on the first surface and over the MEMS structure, the first coating region having a first Young's modulus; and   forming a second coating region over the first coating region, the second coating region having a second Young's modulus,   wherein the first Young's modulus is higher than the second Young's modulus.   
     
     
         8 . The process according to  claim 7 , wherein the first Young's modulus is between 20 GPa and 30 GPa, and the second Young's modulus is between 100 MPa and 5 GPa. 
     
     
         9 . The process according to  claim 7 , wherein the first coating region comprises a polymeric resin. 
     
     
         10 . The process according to  claim 8 , wherein the second coating region comprises a polymeric rubber. 
     
     
         11 . The process according to  claim 7 , wherein forming the first coating region comprise:
 arranging a first molding matrix having a first molding cavity on the surface of the substrate so that the first molding cavity covers the MEMS structure;   injecting a first coating material into the first molding cavity to form the first coating region; and   removing the first molding matrix.   
     
     
         12 . The process according to  claim 11 , wherein injecting the first coating material comprises:
 exposing the first coating material to a first injection temperature; and   injecting the first coating material at the first injection temperature into the first molding cavity at a first transfer pressure.   
     
     
         13 . The process according to  claim 12 , comprising, after injecting the first coating material, curing the first coating material by exposing the first coating material to a first curing temperature for a first time period. 
     
     
         14 . The process according to  claim 13 , wherein forming the second coating region comprises:
 arranging a second molding matrix having a second molding cavity on the surface of the substrate so that the second molding cavity faces and surrounds the first coating region; and   injecting a second coating material into the second molding cavity to form the second coating region.   
     
     
         15 . The process according to  claim 14 , wherein injecting the second coating material comprises:
 exposing the second coating material to a second injection temperature; and   injecting the second coating material at the second injection temperature into the second molding cavity at a second transfer pressure.   
     
     
         16 . The process according to  claim 15 , comprising, after injecting the second coating material, curing the second coating material, wherein curing the second coating material comprises exposing the second curing material to a second curing temperature for a second time period. 
     
     
         17 . A method, comprising:
 arranging a plurality of MEMS structures on a first surface of substrate;   covering the plurality of MEMS structures with a plurality of first coating regions, respectively, the first coating regions having a first Young's modulus;   covering the plurality of first coating regions with a coating mass and forming a packaged wafer, wherein the coating mass has a second Young's modulus lower than the first Young's modulus; and   dicing the packaged wafer to form a plurality of MEMS devices.   
     
     
         18 . The method according to  claim 17 , wherein the first Young's modulus is between 20 GPa and 30 GPa, and the second Young's modulus is between 100 MPa and 5 GPa. 
     
     
         19 . The method according to  claim 17 , wherein the first coating region is a resin and the second coating region is a rubber. 
     
     
         20 . The method according to  claim 17 , wherein each MEMS device comprises a respective MEMS structure, a respective first coating region, and a respective second coating region derived from dicing the coating mass.