Packaging for fingerprint sensors and methods of manufacture

• US 10,636,717 B2
• Filed: 09/05/2017
• Issued: 04/28/2020
• Est. Priority Date: 03/16/2011
• Status: Active Grant

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated
• Inventors: Huemoeller, Ronald Patrick, Bolognia, David, Darveaux, Robert Francis, Dunlap, Brett Arnold
• Primary Examiner(s): Choudhry, Mohammad M
• Application Number:
  US15/695,478
• Publication Number:
  US 20180090409A1
• Time in Patent Office: 966 Days
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 23/3128 the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 24/17 of a plurality of bump connectors
• CPC Class Codes: H01L 24/19 Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 24/96 the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• 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 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER

Abstract

A fingerprint sensor package, including a sensing side for sensing fingerprint information and a separate connection side for electrically connecting the fingerprint sensor package to a host device, is disclosed. The fingerprint sensor package can also include a sensor integrated circuit facing the sensing side and substantially surrounded by a fill material. The fill material includes vias at peripheral locations around the sensor integrated circuit. The fingerprint sensor package can further include a redistribution layer on the sensing side which redistributes connections of the sensor integrated circuit to the vias. The connections can further be directed through the vias to a ball grid array on the connection side. Some aspects also include electrostatic discharge traces positioned at least partially around a perimeter of the connection side. Methods of manufacturing are also disclosed.

Claims

1. A fingerprint sensor package comprising:

a sensor die having a die top side, a die bottom side, and die lateral sides, wherein the sensor die comprises sensing electronics;

a sensing area on the die top side;

a top side trace, at least a portion of which is directly above the sensor die;

a bottom side trace, at least a portion of which is directly below the sensor die;

a conductive via that electrically connects the top side trace and the bottom side trace;

an encapsulant that covers at least the die lateral sides;

and a protective layer that covers the sensing area;

wherein the protective layer is separated from the die top side by at least one intervening layer;

wherein a lateral side of the protective layer, a lateral side of the at least one intervening layer, and a lateral side of the encapsulant are coplanar.

2. The fingerprint sensor package of claim 1, wherein the protective layer covers the entire die top side.

3. The fingerprint sensor package of claim 2, wherein the protective layer covers an entire top side of the encapsulant.

4. The fingerprint sensor package of claim 1, wherein:

the protective layer comprises a plurality of lateral sides; and

the encapsulant comprises a plurality of lateral sides, each of which is coplanar with a respective one of the lateral sides of the protective layer.

5. The fingerprint sensor package of claim 1, wherein the protective layer is less than 25 microns thick.

6. A fingerprint sensor package comprising:

a sensor die having a die top side, a die bottom side, and die lateral sides, w herein the sensor die comprises sensing electronics;

a sensing area on the die top side;

a top side trace, at least a portion of which is directly above the sensor die;

a bottom side trace, at least a portion of which is directly below the sensor die;

a conductive via that electrically connects the top side trace and the bottom side trace;

and an encapsulant that covers at least a portion of the die bottom side and covers at least a portion of each of the die lateral sides;

a connection point directly below the sensor die; and

a conductive ball attached to the connection point,

Wherein an upper end of the conductive ball is higher than a lowest surface of the encapsulant, and a lower end of the conductive ball is lower than the lowest surface of the encapsulant.

7. The fingerprint sensor package of claim 6, wherein the encapsulant covers the entire die bottom side.

8. The fingerprint sensor package of claim 6, wherein a lowest surface of the encapsulant is at least as low as a lowest surface of the bottom side trace.

9. The fingerprint sensor package of claim 6, wherein a top side of the encapsulant is substantially coplanar with the die top side.