| CPC G01L 1/18 (2013.01) [G01L 1/16 (2013.01); G01L 1/26 (2013.01)] | 14 Claims |
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1. A force sensing device comprising:
a force attenuator comprising a deformable slab and a solid-nondeformable slab, wherein:
the force attenuator defines a first surface area for receiving an applied force;
the deformable slab defines a first surface and a second surface, wherein the first surface opposes the second surface;
the non-deformable slab defines a third surface and a fourth surface, wherein the third surface opposes the fourth surface;
the third surface provides the first surface area and the fourth surface of the non-deformable slab is disposed on the first surface of the deformable slab; and
areas of the first surface, the second surface, and the third surface are an identical size and an identical shape such that a relationship between sensitivity attenuation and an area ratio is linear, the areas include the first surface area and the area ratio is a ratio of the areas of the first surface, the second surface, and the third surface;
a cavity formed by the deformable slab such that an opening of the cavity is exposed at the second surface of the deformable slab so that the applied force is transferred to a force sensor within the cavity;
the force sensor provided in the cavity so as to be exposed from the second surface;
a package substrate arranged in the cavity; and
one or more electrical connectors arranged in the cavity and electrically connecting the package substrate to the force sensor, wherein:
the force sensor defines a second surface area for receiving the applied force through the force attenuator;
the force sensor comprises one or more piezoelectric sensing elements, each piezoelectric sensing element comprising a piezoelectric material arranged between a first electrode and a second electrode; and
the second electrode of at least one piezoelectric sensing element is arranged over a respective electrical connector and electrically connected to the respective electrical connector.
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