Packaging for fingerprint sensors and methods of manufacture

• US 9,754,852 B2
• Filed: 08/01/2016
• Issued: 09/05/2017
• 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:
  US15/225,565
• Publication Number:
  US 20160343634A1
• Time in Patent Office: 400 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 method of fabricating a biometric object sensor wafer level fan out package, the method comprising:

forming a sensor control integrated circuit;

forming a molded fill material to at least partially encapsulate the sensor control integrated circuit;

forming a sensing side redistribution layer, wherein the sensing side redistribution layer is disposed on a sensing side of the package, and wherein the sensing side redistribution layer comprises at least one passivation layer and a metal layer, wherein the metal layer of the sensing side redistribution layer further comprises metal redistribution traces and a metal sensor array in the sensing side redistribution layer, the metal sensor array further including a plurality of capacitively coupled drivers and pick-ups configured to detect ridges and valleys of a fingerprint;

forming a connection side redistribution layer, wherein the connection side redistribution layer is on an opposite side of the package relative to the sensing side;

forming at least one ball grid array electrical connector mounted on the connection side of the package; and

forming a protective coating on the sensing side of the package disposed on the sensing side redistribution layer.

2. The method of claim 1, wherein the molded fill material completely encapsulates the integrated circuit.

3. The method of claim 1, further comprising:

connecting the at least one ball grid array electrical connector to the sensing side of the package through a through mold via.

4. The method of claim 1, wherein the connection side of the package comprises a printed circuit board disposed between the at least one ball grid array electrical connector and the sensor control integrated circuit.

5. The method of claim 1 wherein the molded fill material is formed in an opening in a printed circuit board containing the sensor control integrated circuit.

6. The method of claim 1, wherein the package is a fingerprint sensor package.

7. The method of claim 1, further comprising:

forming an interposer board, wherein the interposer board is disposed between the sensing side redistribution layer and the connection side redistribution layer.

8. The method of claim 1, wherein the connection side redistribution layer comprising a multilayer printed circuit board.

9. The method of claim 1, wherein the at least one passivation layer comprises a first passivation layer disposed between the sensor control integrated circuit and the metal layer.

10. The method of claim 9, wherein the at least one passivation layer further comprises a second passivation layer, wherein the metal layer is disposed between the first passivation layer and the second passivation layer.

11. The method of claim 1, further comprising:

forming a secondary integrated circuit, wherein the secondary integrated circuit is disposed within the molded fill material along with the sensor control integrated circuit.

12. The method of claim 11, wherein the secondary integrated circuit includes a light emitting diode.