Fingerprint sensor module

Patent metadata

Field	Value
Publication number	US-10902235-B2
Application number	US-201815978100-A
Country	US
Kind code	B2
Filing date	May 12, 2018
Priority date	May 12, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

According to a first aspect of the present disclosure, a fingerprint sensor module is provided, comprising: an assembly comprising a substrate and a fingerprint sensor mounted on one side of the substrate; wherein the fingerprint sensor comprises a set of sensor elements and a measurement unit; and wherein the measurement unit is configured to concurrently measure capacitances on subsets of the set of sensor elements. According to a second aspect of the present disclosure, a corresponding method of producing a fingerprint sensor module is conceived.

First claim

The invention claimed is:

1. A fingerprint sensor module comprising:
a substrate; and
a fingerprint sensor mounted on one side of the substrate and including a set of sensor circuits having capacitive elements and including a measurement circuit, the measurement circuit being configured to concurrently measure capacitances of mutually different subsets of the sensor circuits in the set of sensor circuits, and to ascertain capacitances of each individual sensor circuit within the set based on the concurrently-measured capacitances of the sensor circuits in the mutually different subsets.

2. The module of claim 1 , wherein the substrate and the fingerprint sensor form a T-shaped assembly.

3. The module of claim 1 , wherein the substrate is a polymer substrate or a glass substrate.

4. The module of claim 1 , further comprising a coating on the substrate.

5. The module of claim 1 , wherein the fingerprint sensor is attached to the substrate by a solder layer, an electro-plating layer, or a foil.

6. The module of claim 1 , wherein the measurement circuit comprises a switched capacitor integrator.

7. The module of claim 1 , wherein the measurement circuit is configured to sequentially measure the capacitances on the mutually different subsets of the set of sensor circuits.

8. A fingerprint processing system comprising the module of claim 1 , and a processing circuit configured to process the concurrently measured capacitances.

9. The system of claim 8 , wherein the processing circuit-is further configured to derive a capacitance on one or more individual sensor circuits from said concurrently measured capacitances.

10. The system of claim 8 , wherein the processing circuit is a microcontroller, and wherein each of the sensor circuits includes at least one circuit elements to sense a change in capacitance.

11. A smart card comprising the system of claim 8 .

12. The smart card of claim 11 , further comprising a plurality of wires embedded in a layer of said card, wherein said wires connect the fingerprint processing module with other components of the card.

13. The card of claim 12 , wherein one or more endings of said wires have a square spiral shape.

14. A method of producing a fingerprint sensor module, the method comprising providing the module with:
a substrate; and
a fingerprint sensor mounted on one side of the substrate and including a set of sensor circuits having capacitive elements and including a measurement-circuit, the measurement circuit being configured to concurrently measure capacitances of mutually different subsets of the set of sensor circuits and to ascertain capacitances of individual ones of the sensor circuits, based on the sum of the measured capacitances for each of the subsets, wherein the fingerprint sensor is configured and arranged to:
sequentially measure capacitances of a plurality of the subsets, each subset including a different combination of ones of the sensor circuits relative to the other subsets, each capacitance measurement providing a combined capacitance value for all of the sensor circuits in the subset; and
derive individual capacitance values for each of the sensor circuits, based upon the respective capacitance measurements for the plurality of subsets.

15. A fingerprint sensor module comprising:
a substrate; and
a fingerprint sensor mounted on one side of the substrate and including a set of sensor circuits having capacitive elements and including a measurement circuit, the measurement circuit being configured to concurrently measure capacitances of mutually different subsets of the set of sensor circuits, and to ascertain capacitances of individual ones of the sensor circuits based on the measured capacitances of the mutually different subsets, wherein the fingerprint sensor is configured and arranged to:
sequentially measure capacitances of a plurality of the subsets, each subset including a different combination of ones of the sensor circuits relative to the other subsets, each capacitance measurement providing a combined capacitance value for all of the sensors in the subset; and
derive individual capacitance values for each of the sensor circuits, based upon the respective capacitance measurements for the plurality of subsets.

16. The module of claim 1 , wherein the fingerprint sensor is configured and arranged to:
sample capacitances of an array of the sensor circuits by measuring, for each subset, combined capacitances of the sensor circuits in the subset, each subset including a different combination of the sensor circuits; and
assess individual capacitances of the sensor circuits based on the sampled capacitances for each respective subset.

17. The module of claim 1 , wherein:
the fingerprint sensor is embedded between lower and upper surfaces of a smart card, wherein the substrate forms part of the upper surface; and
the substrate is configured and arranged to insulate the fingerprint sensor from a user's finger placed on the substrate.

18. A fingerprint sensor module comprising:
a substrate; and
a fingerprint sensor mounted on one side of the substrate and including a set of sensor circuits having capacitive elements and including a measurement circuit, the measurement circuit being configured to concurrently measure respective capacitances of and associated with respective subsets of the set of sensor circuits, and to ascertain capacitances of each individual one of the sensor circuits in the set based on the measured respective capacitances of the different subsets, wherein each of the sensor circuits includes at least one circuit element to sense a change in capacitance, the substrate is arranged as a layer adjacent to another layer that includes the fingerprint sensor, and wherein the measurement circuit includes a sampler circuit and switched capacitor integrator configured to sample and measure the respective capacitances.

19. The module of claim 18 , wherein the switched capacitor integrator of the measurement circuit further includes an operational transconductance amplifier.

Assignees

• Nxp Bv

Inventors

• Suwald Thomas

Classifications

• G06K19/0718 Primary

  the sensor being of the biometric kind, e.g. fingerprint sensors (fingerprint sensors in general G06V40/13; biometric access-control systems in general, see G07C9/00) · CPC title

• G06V40/1306 Primary

  non-optical, e.g. ultrasonic or capacitive sensing · CPC title

• G06F3/047

  using sets of wires, e.g. crossed wires · CPC title

• G06F3/0443

  using a single layer of sensing electrodes · CPC title

• G06K9/0002 Primary

  Physics · mapped topic