Capacitive sensor packaging
An apparatus comprises a fingerprint sensor having a set of capacitive elements configured for capacitively coupling to a user fingerprint. The fingerprint sensor may be disposed under a control button or display element of an electronic device, for example one or more of a control button and a display component. A responsive element is responsive to proximity of the user fingerprint, for example one or both of a first circuit responsive to motion of the control button, and a second circuit responsive to a coupling between the fingerprint and a surface of the display element. The fingerprint sensor is disposed closer to the fingerprint than the responsive element. The control button or display component may include an anisotropic dielectric material, for example sapphire.
1. An assembly for an electronic device, comprising:
a device housing defining an opening;
a fingerprint sensor;
plastic molded above the fingerprint sensor, the plastic defining a button disposed to fit in the opening;
a switch stacked vertically below the fingerprint sensor; and
a button support plate attached to the device housing and positioned below the switch.
2. The assembly as in claim 1 , further comprising:
a flexible element coupled to the fingerprint sensor and disposed to receive and transmit force imposed on the button to the switch, the flexible element configured to receive and transmit electrical signals from the fingerprint sensor.
3. The assembly as in claim 2 , further comprising a stiffener element positioned below the flexible element, between the flexible element and the switch.
4. The assembly as in claim 1 , wherein the switch comprises a tactile dome switch.
5. The assembly as in claim 1 , further comprising a capacitive plate positioned near the button.
6. The assembly as in claim 1 , further comprising at least one of a capacitive plate or a grounding element positioned in a sub-housing including the button.
7. The assembly as in claim 1 , further comprising a grounding element positioned near the button.
8. The assembly as in claim 7 , wherein the grounding element is positioned directly to a side of the fingerprint sensor.
9. The assembly as in claim 1 , further comprising an electromagnetic shield adjacent the fingerprint sensor.
10. The assembly as in claim 1 , wherein the fingerprint sensor comprises a grid of capacitive elements.
11. An electronic device, comprising:
a device housing; and
an input assembly coupled to the device housing and comprising:
a fingerprint sensor;
a button molded above the fingerprint sensor;
a switch stacked vertically below the fingerprint sensor; and
a button support plate disposed below the switch and coupled to the device housing.
12. The electronic device as in claim 11 , further comprising:
a flexible element coupled to the fingerprint sensor and disposed to receive and transmit force imposed on the button to the switch, the flexible element configured to receive and transmit electrical signals from the fingerprint sensor.
13. The electronic device as in claim 12 , wherein:
the electronic device further comprises a processor; and
the flexible element is operably coupled to the processor and configured to transmit electrical signals from the fingerprint sensor to the processor.
14. The electronic device as in claim 11 , wherein:
the device housing defines an opening; and
the input assembly is at least partially disposed within the opening.
15. The electronic device as in claim 14 , wherein:
the device housing comprises an upper portion and a base portion;
the opening is defined in the upper portion; and
the button support plate is coupled to the base portion.
16. The electronic device as in claim 11 , wherein the input assembly further comprises a sub-housing that houses one or more components of the input assembly.
17. The electronic device as in claim 11 , wherein the button is formed of plastic.
18. The electronic device as in claim 11 , wherein:
the device housing defines an opening; and
a top surface of the button is recessed in the opening.
19. The electronic device as in claim 11 , wherein the fingerprint sensor comprises an optical sensor.
20. The electronic device as in claim 11 , wherein the fingerprint sensor comprises a grid of capacitive elements.