FINGERPRINT SENSOR MODULE COMPRISING ANTENNA AND METHOD FOR MANUFACTURING A FINGERPRINT SENSOR MODULE

Abstract

There is provided a fingerprint sensor module comprising a fingerprint sensor device. The fingerprint sensor device comprises a sensing array consisting of a plurality of sensing elements, the sensor device being configured to acquire an image of a finger placed on a sensing surface of the fingerprint sensor module. The fingerprint sensor module further comprises a substrate comprising an opening, wherein the fingerprint sensor device is arranged in the opening of the substrate and wherein the substrate comprises an antenna embedded in the substrate, the antenna being electrically connected to the fingerprint sensor device.

Claims

1. A fingerprint sensor module comprising: a fingerprint sensor device comprising a sensing array consisting of a plurality of sensing elements, the sensor device being configured to acquire an image of a finger placed on a sensing surface of the fingerprint sensor module; a substrate comprising an opening; wherein the fingerprint sensor device is arranged in the opening of the substrate and wherein the substrate comprises an antenna embedded in the substrate, the antenna being electrically connected to the fingerprint sensor device.

2. The fingerprint sensor module according to claim 1, wherein the antenna is arranged to encircle the opening comprising the fingerprint sensor device.

3. The fingerprint sensor module according to claim 1, wherein the antenna is arranged below the fingerprint sensor device, on a side of the fingerprint sensor device opposite the side comprising the sensing array.

4. The fingerprint sensor module according to claim 1, wherein the substrate comprises a plurality of conductive layers, and wherein the antenna is formed in said plurality of conductive layers of the substrate.

5. The fingerprint sensor module according to claim 1, wherein the substrate is a laminate substrate comprising a plurality of carrier layers interspaced with a plurality of electrically conductive layers.

6. The fingerprint sensor module according to claim 5, wherein the substrate is an epoxy-based laminate substrate.

7. The fingerprint sensor module according to claim 1, wherein the substrate comprises a glass or ceramic material having a plurality of electrically conductive layers embedded therein.

8. The fingerprint sensor module according to claim 1, wherein the opening of the substrate is a recess in the substrate.

9. The fingerprint sensor module according to claim 1, wherein the opening of the substrate is a through hole through the substrate.

10. The fingerprint sensor module according to claim 1, wherein the fingerprint sensor device comprises at last one connection pad located adjacent to the sensing array, and wherein the fingerprint sensor device is electrically connected to the antenna via the connection pad.

11. The fingerprint sensor module according to claim 10, wherein the electrical connection between the connection pad of the fingerprint sensor device and the antenna is formed as a conductive trace located in the same plane as the connection pad.

12. The fingerprint sensor module according to claim 11, wherein the connection pad is located in the same plane as the sensing array.

13. The fingerprint sensor module according to claim 10, further comprising a via connection in said substrate, wherein the connection pad is electrically connected to the antenna by means of the via connection.

14. The fingerprint sensor module according to claim 1, wherein the substrate comprises substrate connection pads for electrically connecting the fingerprint sensor module to external circuitry.

15. A smart card comprising a fingerprint sensor module according to claim 1, wherein the fingerprint sensor module is arranged in an opening of the smart card and electrically connected to smart card circuitry by means of a substrate connection pad.

16. A method for manufacturing a fingerprint sensor module, the method comprising: providing a fingerprint sensor device comprising a sensing array consisting of a plurality of sensing elements, the sensor device being configured to acquire an image of a finger placed on a sensing surface of the fingerprint sensor module; providing a substrate comprising an antenna embedded in the substrate, the substrate further comprising an opening for receiving the fingerprint sensor device; arranging the fingerprint sensor device in the opening; and forming an electrical connection between the fingerprint sensor device and the antenna.

17. The method according to claim 16, wherein the substrate opening is an opening through the substrate, the method further comprising: arranging the substrate on a carrier; arranging the fingerprint sensor device on the carrier in the substrate opening with the sensing array facing the carrier; depositing a mold material covering a backside of the fingerprint sensor device and a backside of the substrate to mechanically attach the fingerprint sensor device to the substrate; removing the carrier; and forming an electrical connection between a connection pad located on the fingerprint sensor device adjacent to the sensing array and the antenna.

18. The method according to claim 16, wherein the substrate opening is a recess in the substrate, the method further comprising: arranging the fingerprint sensor device in the substrate recess; depositing a mold material surrounding filling a space between the fingerprint sensor device and the sidewalls of the substrate recess to mechanically attach the fingerprint sensor device to the substrate; and forming an electrical connection between a connection pad located on the fingerprint sensor device adjacent to the sensing array and the antenna.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing an example embodiment of the invention, wherein:

[0032] FIGS. 1A-B schematically illustrate a fingerprint sensor module according to an embodiment of the invention;

[0033] FIG. 2 is flow chart outlining the general steps of method for manufacturing a fingerprint sensor module according to an embodiment of the invention;

[0034] FIGS. 3A-E schematically illustrate steps of method for manufacturing a fingerprint sensor module according to an embodiment of the invention;

[0035] FIG. 4 schematically illustrates a fingerprint sensor module according to an embodiment of the invention;

[0036] FIG. 5 is flow chart outlining the general steps of method for manufacturing a fingerprint sensor module according to an embodiment of the invention;

[0037] FIGS. 6A-C schematically illustrate steps of method for manufacturing a fingerprint sensor module according to an embodiment of the invention; and

[0038] FIG. 7 schematically illustrate a smartcard comprising a fingerprint sensor module according to an embodiment of the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0039] In the present detailed description, various embodiments of the system and method according to the present invention are mainly described with reference to a capacitive fingerprint sensor device. However, various embodiments of the invention are equally applicable also to other types of fingerprint sensors, such as optical, ultrasound and thermal fingerprint sensors.

[0040] FIG. 1A schematically illustrates a side view of a fingerprint sensor module 100 according to an embodiment of the invention. The fingerprint sensor module 100 comprises a fingerprint sensor device 102 which in turn comprises a sensing array 104 consisting of a plurality of sensing elements. The sensor device 102 is configured to acquire an image of a finger placed on a sensing surface 106 of the fingerprint sensor module 100. In a capacitive finger sensor device 102, each sensing element comprises an electrically conductive structure and associated detection circuitry connected to the electrically conductive structure and configured to acquire a signal proportional to the capacitive coupling between each sensing structure and a finger placed on the sensing surface 106 of the fingerprint sensor module 100.

[0041] The fingerprint sensor module 100 further comprises a substrate 108 comprising an opening 110, and the fingerprint sensor device 102 is arranged in the opening 110 of the substrate 108. The substrate 108 further comprises an electrically conductive antenna 112 embedded in the substrate 108, the antenna 110 being electrically connected to the fingerprint sensor device 102. Here, the electrical connection 114 between the antenna and the fingerprint sensor device 102 is a conductive trace 114 connecting the antenna 112 to a connection pad 116 of the fingerprint sensor device 102, located on the same side of the fingerprint sensor device 102 as the sensing array 104. However, it is also possible to form an electrical connection to the fingerprint sensor device 102 on the opposite side, i.e. the backside, of the fingerprint sensor device 102.

[0042] As illustrated in FIG. 1A and in the top view of the of the fingerprint sensor module of FIG. 1B, the antenna 112 is arranged to surround the opening 110 of the substrate 108. Moreover, the antenna 112 is comprises antenna loops arranged in parallel in several layers of the substrate 108. The substrate may for example be a laminate substrate 108 where the antenna is located between layers of the laminate substrate 108. The substrate 108 may for example be a PCB substrate 108. However, it is also possible to provide an antenna in only one layer of the substrate 108.

[0043] The opening 110 of the substrate is a through opening reaching all the way through the substrate 108 and the fingerprint sensor device 102 is held in place by means of a mold material 118, an encapsulant or any other suitable filling material.

[0044] FIG. 2 is a flow chart outlining the general steps of a method for manufacturing fingerprint sensor module 100 according to an embodiment of the invention. The flow chart of FIG. 2 will be discussed with further reference to FIGS. 3A.C illustrating selected steps of a method for manufacturing the fingerprint sensor module 100.

[0045] The method comprises providing 200 a fingerprint sensor device 102 as described above in relation to FIG. 1A. A substrate 108 comprising an antenna 112 embedded in the substrate 108 is provided 202. The substrate is arranged on a carrier 300 such as an adhesive tape a wafer carrier, a plate carrier or the like as illustrated in FIG. 3A. The substrate 108 comprises an opening 110 for receiving the fingerprint sensor device 102.

[0046] The method further comprises arranging 204 the fingerprint sensor device 102 in the opening 110 as illustrated in FIG. 3B. Next, illustrated in FIG. 3C, a mold material 118 is deposited in the opening 110 to protect and to hold the fingerprint sensor device 102 in place in the substrate opening 110.

[0047] In the following step, illustrated in FIG. 3D, the carrier 300 is removed, or the fingerprint sensor module is removed from the carrier 300 such that the surface of the fingerprint sensor device 102 is exposed. This enables the formation 206 of an electrical connection 114 between the antenna 112 of the substrate 108 and connection pads 116 fingerprint sensor device 102 as illustrated in FIG. 3E. The electrical connection 114 may be formed directly between the fingerprint sensor device 102 and the antenna 112. It is also possible to connect the fingerprint sensor device 102 to routing circuitry or intermediate connection pads of the substrate which in turn are electrically connected to the antenna 112. The electrical connection 114 may be formed using metal electroplating or any other known metal deposition method. Moreover, the electrical connection between the fingerprint sensor device 102 and the antenna 112 may be located on the backside of the fingerprint sensor device 102 where a via connection may be provided to reach through the fingerprint sensor device 102.

[0048] Thereby, the fingerprint sensor device 102 is electrically connected to the antenna 112 such that the fingerprint sensor device 102 for example can receive energy received by the antenna 112.

[0049] FIG. 3E further illustrates depositing a protective layer 304 to cover the top surface of the fingerprint sensor module 100. It should be noted that the protective layer 304 may comprise an encapsulant or a coating. The protective layer 301 may further comprise a plurality of layers, such as an adhesive, a pigment layer, a dielectric layer and a top surface coating. The fingerprint sensor module 100 may also comprise a protective plate in the form of a glass or ceramic plate. Thereby, the fingerprint sensor module 100 is completed and ready form arranging in a device such as a smartcard.

[0050] FIG. 4 schematically illustrates a fingerprint sensor module 400 according to an embodiment of the invention where the fingerprint sensor device 102 is arranged in a recess 401 of the substrate 108. The opening 401 in the substrate 108 is thereby not a through opening. Accordingly, the opening 401 should be seen as the portion of the substrate where substrate material has been removed to house the fingerprint sensor device 102. It is also possible to directly form a substrate 108 having the desired opening 110, 401. Moreover, the antenna 402 is here located underneath the fingerprint sensor device 102. This allows for the overall size of the fingerprint sensor module 400 to be reduced compared to if an antenna is arranged to encircle the fingerprint sensor device 102. However, it is equally well possible to arrange an antenna to encircle the fingerprint sensor device 102, even if the fingerprint sensor device 102 is located in a recess 401 and not in a through opening.

[0051] FIG. 5 is flow chart outlining the general steps of method for manufacturing a fingerprint sensor module 400 as illustrated in FIG. 4. The method will be discussed with further reference to FIGS. 6A-C illustrating selected steps of the method.

[0052] The method illustrated in FIGS. 6A-C is in many parts similar to the method discussed above with reference to FIG. 2 and FIGS. 3A-E. First, a substrate 108 comprising an opening in the form of a recess 401 is provided. The fingerprint sensor device 102 is then arranged 500 in the substrate recess 401 as illustrated in FIG. 6A. Next, illustrated in FIG. 6B, a mold material 118 is deposited 502 to surround the fingerprint sensor device 102 and to fill a space between the fingerprint sensor device 102 and the sidewalls of the substrate recess 401, thereby mechanically attaching the fingerprint sensor device 102 to the substrate 108.

[0053] In the next step, illustrated in FIG. 6C, an electrical connection 114 is formed 504 between a connection pad 116 located on the fingerprint sensor device 102 adjacent to the sensing array and a corresponding connection pad of the substrate which connects the fingerprint sensor device 102 to the antenna 402. Finally, a protective layer 304 is deposited to cover the fingerprint sensor device 102 and the substrate 108. FIG. 6C also illustrates a bump on the backside of the fingerprint sensor module, i.e. a substrate connection pad, for connecting to external circuitry.

[0054] FIG. 7 schematically illustrates a smart card 700 comprising a fingerprint sensor module 100 arranged in an opening of the smartcard 700. The fingerprint sensor module 100 is communicatively coupled to integrated circuitry of the smartcard 700 so that an identity of a user can be verified. The opening of the smart card 700 may be a through opening or a recess. Moreover, the opening may have T-shaped profile and the fingerprint sensor module 100, 400 may have a corresponding T-shaped profile to fit into the T-shaped opening of the smart card 700, thereby simplifying an assembly process.

[0055] Even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. Also, it should be noted that parts of the method and module may be omitted, interchanged or arranged in various ways, the method and module yet being able to perform the functionality of the present invention.

[0056] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.