Sensor packages

Abstract

A sensor package comprising: a sensor, wherein the sensor comprises a sensing structure formed in a material layer and one or more further material layers arranged to seal the sensing structure to form a hermetically sealed sensor unit; a support structure; one or more springs flexibly fixing the hermetically sealed sensor unit to the support structure; wherein the one or more springs are formed in the same material layer as the sensing structure of the sensor unit; and one or more external package wall(s) encapsulating the sensor unit, the support structure, and the one or more springs, wherein the support structure is fixed to at least one of the package wall(s). The springs decouple mechanical stresses between the sensor unit and the external package wall(s) so as to reduce the long term drift of scale factor and bias.

1 . A method of manufacturing a sensor package, the method comprising:
 forming a sensing structure in a material layer;   forming one or more springs in the same material layer as the sensing structure;   adding one or more further material layers to seal the sensing structure to form a hermetically sealed sensor unit with the one or more springs flexibly fixing the hermetically sealed sensor unit to a support structure; and   fixing the support structure to one or more external package wall(s), the one or more external package wall(s) encapsulating the sensor unit, the support structure, and the one or more springs.   
     
     
         2 . The method of  claim 1 , further comprising:
 forming the support structure in the same material layer as the sensing structure of the sensor unit and the one or more springs.   
     
     
         3 . The method of  claim 2 , further comprising:
 forming a squeeze film damping structure between the hermetically sealed inertial sensor unit and the support structure.   
     
     
         4 . The method of  claim 3 , further comprising:
 forming the squeeze film damping structure in the same material layer as the sensing structure of the sensor unit and the spring(s).   
     
     
         5 . The method of  claim 4 , further, comprising:
 forming an electrically conductive path across the one or more springs such that the sensor unit is electrically connected to at least one of the external package wall(s).   
     
     
         6 . The method of any  claim 1 , further, comprising:
 forming an electrically conductive path across the one or more springs such that the sensor unit is electrically connected to at least one of the external package wall(s).   
     
     
         7 . The method of any  claim 2 , further, comprising:
 forming an electrically conductive path across the one or more springs such that the sensor unit is electrically connected to at least one of the external package wall(s).   
     
     
         8 . The method of any  claim 3 , further, comprising:
 forming an electrically conductive path across the one or more springs such that the sensor unit is electrically connected to at least one of the external package wall(s).