Biometric sensor and method for its production

• US 20010012201A1
• Filed: 01/16/2001
• Published: 08/09/2001
• Est. Priority Date: 07/14/1998
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Siemens AG
• Inventors: Fries, Manfred, Munch, Thomas, Fischbach, Reinhard
• Granted Patent: US 6,528,723 B2
• Time in Patent Office: Days
• US Class Current: 361/807
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49171 with encapsulating

Abstract

In a biometric sensor and a method for its production, a sensor chip is provided with connecting contacts in the form of electrically conductive bumps. The sensor chip is inserted into a chip housing, the bumps making contact with corresponding connecting leads belonging to the chip housing. At the same time as this contact is made, the sensor chip is bonded adhesively into the chip housing by an adhesive layer, which surrounds the sensor field in a sealing manner.

Claims

1. A biometric sensor, comprising:

a housing;

connecting leads disposed one of on and in said housing;

a sensor chip disposed in said housing, said sensor chip having a top, a field sensor, and connecting contacts in a form of electrically conductive bumps, said electrically conductive bumps making contact with said connecting leads and having a given height;

a scratch protection covering disposed on said top of said sensor chip; and

an adhesive layer disposed between said scratch protection covering and said housing, said adhesive layer disposed at least around said sensor field, said adhesive layer having a thickness matched to said given height of said electrically conductive bumps creating a leak-tight connection between said sensor chip and housing.

2. The sensor according to

claim 1

, including at least one further supporting bump disposed on said top of said sensor chip at a point which prevents said sensor chip from tilting relative to said housing.

3. The sensor according to

claim 1

, wherein said adhesive layer is a frame-shaped adhesive film.

4. The sensor according to

claim 1

, wherein said housing is an injection-molded housing.

5. The sensor according to

claim 1

, wherein said connecting leads are embedded in said housing and are routed to an outer edge of said housing.

6. A method of producing a biometric sensor, which comprises the steps of:

providing a wafer having sensor chips with connecting contacts;

applying conductive bumps to the connecting contacts of the sensor chips;

covering a front side of the wafer with a scratch protection covering;

removing the scratch protection covering from over a top of the conductive bumps;

separating the sensor chips from one another;

applying an adhesive layer around a sensor field of a respective sensor chip, the adhesive layer having a thickness being matched to a height of the conductive bumps such that, in a subsequent method step, a leak-tight connection between the sensor chip and a chip housing is created;

introducing the sensor chip into the chip housing, the chip housing having electrical connecting leads disposed one of in and on the chip housing; and

carrying out simultaneously an adhesive bonding of the respective sensor chip to the chip housing and making contact between the conductive bumps and the electrical connecting leads belonging to the chip housing.

7. The method according to

claim 6

, which comprises removing the scratch protection covering from the top of the conductive bumps by using a chemical mechanical polishing process.

8. The method according to

claim 6

, which comprises exposing the tops of the conductive bumps such that all exposed bump tops lie in a same plane.

9. A method of producing a biometric sensor, which comprises the steps of:

providing a wafer having sensor chips with connecting contacts;

applying conductive bumps to the connecting contacts of the sensor chips;

covering a front side of the wafer with a scratch protection covering, openings in the scratch protection covering being kept free by use of a masking in an area of the conductive bumps;

separating the sensor chips from one another;

applying an adhesive layer around a sensor field of a respective sensor chip, the adhesive layer having a thickness being matched to a height of conductive bumps such that, in a subsequent method step, a leak-tight connection between the sensor chip and a chip housing is created;

introducing the sensor chip into the chip housing, the chip housing having electrical connecting leads disposed one of in and on the chip housing; and

carrying out simultaneously an adhesive bonding of the sensor chip to the chip housing and a making of contact between the conductive bumps and the electrical connecting leads belonging to the chip housing.