Fingerprint Sensor and Interconnect

• US 20080079100A1
• Filed: 11/05/2007
• Published: 04/03/2008
• Est. Priority Date: 05/31/2002
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Manansala, Michael
• Application Number:
  US11/934,863
• Publication Number:
  US 20080079100A1
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48228 the bond pad being disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• CPC Class Codes: H01L 2224/48644 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/85444 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15174 : in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape

Abstract

Particular embodiments of the present invention are directed to a flexible fingerprint sensor interconnect apparatus that includes a fingerprint sensor chip having at least one die contact and a multilayer flexible substrate. Furthermore, the apparatus includes at least one conductive trace in the multilayer flexible substrate, and the at least one conductive trace has an exposed contact region that is directly electrically coupled to the at least one contact pad.

Claims

1. A flexible fingerprint sensor interconnect apparatus, comprising:

a fingerprint sensor chip having at least one die contact;

a multilayer flexible substrate; and

at least one conductive trace in the multilayer flexible substrate, wherein the at least one conductive trace has an exposed contact region that is directly electrically coupled to the at least one contact pad.

2. The apparatus of claim 1, wherein the exposed contact region is wire bonded to the at least one die contact.

3. The apparatus of claim 1, wherein the exposed contact region is coupled to the at least one die contact using a ball/bump method.

4. The apparatus of claim 1, wherein the exposed contact region is coupled to the at least one die contact using a tape automated bonding method.

5. The apparatus of claim 1, further comprising an encapsulation material covering the exposed contact region and the die contact.

6. The apparatus of claim 5, wherein the encapsulation material is a pre-molded package.

7. The apparatus of claim 5, wherein the encapsulation material is transfer molded.

8. The apparatus of claim 1, wherein the multilayer flexible substrate includes a second contact region that is configured to mate with a mating conductor.

9. The apparatus of claim 1, wherein the multilayer flexible substrate includes a second contact region and a third contact region, wherein the second and third contact regions are configured to mate with corresponding mating connectors.

10. A flexible fingerprint sensor interconnect apparatus, comprising:

a multilayer flexible substrate having conductive traces that lead to a connector at one end of the substrate for connecting the flexible fingerprint sensor interconnect apparatus to an external circuit;

a fingerprint sensor chip mounted on an end portion of the multilayer flexible substrate distal from the connector end, the fingerprint sensor chip having a sensor surface and sensor contacts, the sensor contacts electrically coupled to the conductive traces; and

a rigid molded package coupled to a portion of the bottom of the multilayer flexible substrate below the fingerprint sensor chip such that at least a portion of the multilayer flexible substrate is positioned between the fingerprint sensor and the molded package, such that an open top cavity exposing the sensor surface of the fingerprint sensor for access by a user is formed, and such that the portion of the fingerprint sensor interconnect apparatus proximate the molded package is rigid, and the portion of the fingerprint sensor interconnect apparatus distal from the molded package is flexible.

11. The apparatus of claim 10, further comprising a stiffener coupled to the flexible substrate at the connector end thereof.

12. The apparatus of claim 10, wherein:

the conductive traces are positioned internally within the multilayer flexible substrate;

a portion of the multilayer flexible substrate has an opening adjacent to the fingerprint sensor such that a portion of at least some of the conductive traces are exposed in the opening; and

the sensor contacts are electrically coupled to the conductive traces via connecting wires between the sensor contacts and the exposed portions of the conductive traces.

13. The apparatus of claim 12, further comprising an encapsulation material disposed in the cavity covering the wires.

14. A fingerprint sensing apparatus, comprising:

an elongate multilayer flexible substrate having a conductive layer having a plurality of conductive traces;

a fingerprint sensor mounted on top of the elongate multilayer flexible substrate proximate a first end thereof;

the fingerprint sensor having a sensor surface and a plurality of electrical contacts, wherein the sensor electrical contacts are electrically coupled to one or more of the conductive traces in the conductive layer at a location removed from the first end;

a frame mounted below a portion of the elongate multilayer flexible substrate adjacent the first end, such that at least a portion of the elongate multilayer flexible substrate is between the frame and the sensor, and such that the sensor surface is exposed and the portion of the elongate multilayer flexible substrate proximate the frame is rigid; and

a connector disposed at a second end of the elongate multilayer flexible substrate distal from the first end, the connector having a plurality of electrical contacts coupled to the conductive traces.

15. The apparatus of claim 14, further comprising a stiffener coupled proximate to the connector for providing rigidity to the connector.