Ultrasonic fingerprint recognition module, fabricating method thereof, and display device

Patent metadata

Field	Value
Publication number	US-11222192-B2
Application number	US-201916492347-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	May 24, 2018
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

This application provides an ultrasonic fingerprint recognition module including: a base substrate; at least one ultrasonic wave signal receiver and at least one ultrasonic wave signal transmitter on the base substrate, which are on a same side of the base substrate and spaced apart from each other in a first direction parallel to the base substrate; a piezoelectric sensing layer on a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate; and an electrode layer on a side of the piezoelectric sensing layer distal to the base substrate.

First claim

What is claimed is:

1. An ultrasonic fingerprint recognition module, comprising:
a base substrate;
at least one ultrasonic wave signal transmitter and at least one ultrasonic wave signal receiver on the base substrate, wherein the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver are on a same side of the base substrate and spaced apart from each other in a first direction parallel to the base substrate;
a piezoelectric sensing layer on a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate; and
an electrode layer on a side of the piezoelectric sensing layer distal to the base substrate.

2. The ultrasonic fingerprint recognition module of claim 1 , wherein the piezoelectric sensing layer comprises a first portion having a first thickness and a second portion having a second thickness, the first thickness is greater than the second thickness, an orthographic projection of the ultrasonic wave signal transmitter on the base substrate at least partially overlaps an orthographic projection of the first portion on the base substrate, and an orthographic projection of the ultrasonic wave signal receiver on the base substrate at least partially overlaps an orthographic projection of the second portion on the base substrate.

3. The ultrasonic fingerprint recognition module of claim 1 , wherein
the ultrasonic wave signal receiver comprises a plurality of ultrasonic wave signal receiving blocks arranged in a second direction parallel to the base substrate and spaced apart from each other, and the first direction intersects with the second direction.

4. The ultrasonic fingerprint recognition module of claim 3 , wherein
the ultrasonic wave signal transmitter comprises an ultrasonic wave signal transmitting block extending in the second direction and having an elongated shape.

5. The ultrasonic fingerprint recognition module of claim 3 , wherein
the ultrasonic wave signal transmitter comprises a plurality of ultrasonic wave signal transmitting blocks arranged in the second direction and spaced apart from each other.

6. The ultrasonic fingerprint recognition module of claim 4 , further comprising an insulating layer between the ultrasonic wave signal transmitter and the ultrasonic wave signal receiver.

7. The ultrasonic fingerprint recognition module of claim 1 , wherein
the ultrasonic wave signal transmitter comprises a transmitting electrode and is configured to apply a voltage provided by an external circuit to the transmitting electrode such that the piezoelectric sensing layer is excited by a voltage between the transmitting electrode and the electrode layer to generate ultrasonic waves; and
the ultrasonic wave signal receiver comprises a receiving electrode configured to receive an electrical signal into which reflected ultrasonic waves are converted by the piezoelectric sensing layer, and the ultrasonic wave signal receiver is configured to transmit the electrical signal received by the receiving electrode to the external circuit for sensing.

8. The ultrasonic fingerprint recognition module of claim 3 , wherein
a cross section of the ultrasonic wave signal receiving block parallel to the base substrate has a shape of rectangle with a length of side ranging from 40 um to 60 um.

9. The ultrasonic fingerprint recognition module of claim 5 , wherein
a cross section of the ultrasonic wave signal transmitting block parallel to the base substrate has a shape of rectangle with a length of side ranging from 40 um to 60 um.

10. The ultrasonic fingerprint recognition module of claim 2 , wherein the first thickness is 10 um and the second thickness is 5 um.

11. The ultrasonic fingerprint recognition module of claim 1 , wherein a material of the piezoelectric sensing layer comprises one or more copolymers of polyvinyl chloride, polycarbonate, polyvinylidene fluoride, polyvinylidene fluoride trifluoroethylene, polymethyl methacrylate, and polytetrafluoroethylene.

12. The ultrasonic fingerprint recognition module of claim 1 , wherein a material of the electrode layer comprises aluminum.

13. The ultrasonic fingerprint recognition module of claim 1 , further comprising an insulating layer on a side of the electrode layer distal to the base substrate.

14. A display device comprising the ultrasonic fingerprint recognition module of claim 1 and a display panel, wherein the ultrasonic fingerprint recognition module is on a non-light-emitting side of the display panel.

15. A method for fabricating an ultrasonic fingerprint recognition module, comprising:
providing a base substrate;
forming at least one ultrasonic wave signal transmitter and at least one ultrasonic wave signal receiver on the base substrate, wherein the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver are on a same side of the base substrate and spaced apart from each other in a first direction parallel to the base substrate;
forming a piezoelectric sensing layer on a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate; and
forming an electrode layer on a side of the piezoelectric sensing layer distal to the base substrate.

16. The method of claim 15 , wherein the piezoelectric sensing layer is formed to comprise a first portion having a first thickness and a second portion having a second thickness, the first thickness is greater than the second thickness, an orthographic projection of the ultrasonic wave signal transmitter on the base substrate at least partially overlaps an orthographic projection of the first portion on the base substrate, and an orthographic projection of the ultrasonic wave signal receiver on the base substrate at least partially overlaps an orthographic projection of the second portion on the base substrate.

17. The method of claim 15 , wherein forming the piezoelectric sensing layer on the side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate comprises:
providing a transfer template, forming a piezoelectric sensing material layer on the transfer template and patterning the piezoelectric sensing material layer; and
transferring the patterned piezoelectric sensing material layer to a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate to obtain the piezoelectric sensing layer.

18. The method of claim 15 , wherein forming the piezoelectric sensing layer on the side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate comprises:
forming an amorphous piezoelectric polymer material layer on a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate;
pressing and patterning the amorphous piezoelectric polymer material layer; and
crystallizing the amorphous piezoelectric polymer material layer after the pressing and patterning to obtain the piezoelectric sensing layer.

19. The method of claim 15 , further comprising forming an insulating layer on a side of the electrode layer distal to the base substrate.

Assignees

• Chengdu Boe Optoelect Tech Co
• Boe Technology Group Co Ltd

Inventors

• Tang Guoqiang
• Xu Yingsong

Classifications

• G06V40/1306 Primary

  non-optical, e.g. ultrasonic or capacitive sensing · CPC title

• B06B1/0692 Primary

  with a continuous electrode on one side and a plurality of electrodes on the other side · CPC title

• B06B2201/70

  Specific application · CPC title

• G06K9/0002 Primary

  Physics · mapped topic