阅读说明：本技术 指纹识别模组及其驱动方法、制作方法、显示装置 (Fingerprint identification module, driving method and manufacturing method thereof and display device ) 是由 郭玉珍 刘英明 王海生 李佩笑 张晨阳 李秀锋 赵利军 韩艳玲 于 2019-09-12 设计创作，主要内容包括：本公开提供了一种指纹识别模组及其驱动方法、制作方法、显示装置。该指纹识别模组可以包括：接收电极层、压电材料层和驱动电极层。接收电极层包括多个接收电极。该多个接收电极沿第一方向和第二方向阵列设置。压电材料层设置在接收电极层的一侧。驱动电极层设置在压电材料层远离接收电极层的一侧且包括沿第二方向排列的多个驱动电极。各驱动电极为沿第一方向延伸的条状电极,且与沿第一方向排列的多个接收电极交叠。本公开可以提高指纹识别性能。(The disclosure provides a fingerprint identification module, a driving method and a manufacturing method thereof and a display device. This fingerprint identification module can include: a receiving electrode layer, a piezoelectric material layer, and a driving electrode layer. The receiving electrode layer includes a plurality of receiving electrodes. The plurality of receiving electrodes are arranged in an array along a first direction and a second direction. The piezoelectric material layer is disposed on one side of the receiving electrode layer. The driving electrode layer is arranged on one side of the piezoelectric material layer far away from the receiving electrode layer and comprises a plurality of driving electrodes arrayed along the second direction. Each driving electrode is a stripe electrode extending in the first direction and overlapping a plurality of receiving electrodes arranged in the first direction. The present disclosure can improve fingerprint recognition performance.)

A fingerprint identification module, comprising:

a receiving electrode layer including a plurality of receiving electrodes arranged in an array along a first direction and a second direction;

a piezoelectric material layer disposed at one side of the receiving electrode layer; and

a driving electrode layer disposed on a side of the piezoelectric material layer away from the receiving electrode layer and including a plurality of driving electrodes arranged in the second direction,

each driving electrode is a strip electrode extending along the first direction and is overlapped with a plurality of receiving electrodes arranged along the first direction.

The fingerprint identification module of claim 1, wherein,

the plurality of receiving electrodes include a plurality of receiving electrode groups arranged in the second direction, each of the receiving electrode groups including at least two receiving electrodes arranged in the first direction;

each of the driving electrodes overlaps at least two of the receiving electrode groups.

The fingerprint identification module of claim 2, wherein,

the minimum arrangement period of the plurality of driving electrodes arranged along the second direction is substantially equal to half of the wavelength of ultrasonic waves emitted by the fingerprint identification module during operation.

The fingerprint identification module of claim 3,

the minimum arrangement period of the plurality of driving electrodes arranged along the second direction is a distance value which is closest to half of the wavelength of the ultrasonic wave emitted by the fingerprint identification module during operation in a plurality of distance values which are integral multiples of the minimum arrangement period of the plurality of receiving electrodes arranged along the second direction;

wherein, there is a gap between adjacent receiving electrodes, and the range of the ratio R of the width of the gap along the second direction to the minimum arrangement period of the plurality of receiving electrodes arranged along the second direction is: r is more than 0 and less than or equal to 20 percent.

The fingerprint identification module of claim 3 or 4,

the width of each driving electrode along the second direction is smaller than or equal to half of the wavelength of ultrasonic waves emitted by the fingerprint identification module during working.

The fingerprint identification module of any one of claims 1 to 5, wherein said driving electrode layer further comprises: and the retaining wall is positioned between two adjacent driving electrodes.

The fingerprint identification module of claim 6, wherein the dimension of the driving electrode in the direction perpendicular to the driving electrode layer is in a range of 1 micron to 20 microns, and the dimension of the dam in the direction perpendicular to the driving electrode layer is greater than or equal to the dimension of the driving electrode in the direction perpendicular to the driving electrode layer.

The fingerprint identification module of any one of claims 1 to 7, wherein the piezoelectric material layer comprises a plurality of sub-piezoelectric material layers arranged along the second direction,

the plurality of sub-piezoelectric material layers and the plurality of driving electrodes are arranged in a one-to-one correspondence mode.

The fingerprint identification module of any one of claims 1 to 8, further comprising:

the reflecting layer is positioned on one side, far away from the piezoelectric material layer, of the driving electrode layer; and

and the insulating layer is positioned between the reflecting layer and the driving electrode layer.

The fingerprint identification module of any one of claims 1 to 9,

each of the driving electrodes includes: the piezoelectric driving device comprises a first sub driving electrode in contact with the piezoelectric material layer and a second sub driving electrode on one side of the first sub driving electrode far away from the piezoelectric material layer, wherein the thickness of the first sub driving electrode is smaller than that of the second sub driving electrode.

The fingerprint identification module of any one of claims 1 to 10, further comprising: a plurality of drive circuits, each drive circuit electrically connected to one of the receiving electrodes, each drive circuit comprising:

a storage capacitor including a first pole and a second pole;

a first thin film transistor including a first gate electrode, a first source electrode, and a first drain electrode; and

a signal reading sub-circuit for reading the signal,

wherein the receiving electrode, the first source electrode and the first pole are electrically connected to a storage node, the signal reading sub-circuit being configured to read an electrical signal stored in the storage capacitance.

The fingerprint identification module of claim 11, wherein the first thin film transistor is an oxide thin film transistor.

The fingerprint identification module of claim 11, wherein the signal reading sub-circuit comprises:

a second thin film transistor including a second gate electrode, a second source electrode, and a second drain electrode; and

a third thin film transistor including a third gate electrode, a third source electrode, and a third drain electrode,

wherein the second gate is electrically connected to the storage node, the second drain is electrically connected to the third source, the second source is configured to receive a fixed voltage, the third gate is configured to receive a readout instruction signal, and the third drain is configured to output an electrical signal.

The fingerprint identification module of claim 13, further comprising:

a plurality of multiplexers, each multiplexer configured to select an output electrical signal;

a plurality of sets of data signal lines, each set of data signal lines including a plurality of data signal lines, the plurality of sets of data signal lines being electrically connected to the plurality of multiplexers in a one-to-one correspondence, each of the plurality of data signal lines being electrically connected to third drain electrodes of third thin film transistors of the plurality of driving circuits arranged along the first direction;

a control circuit electrically connected to the plurality of multiplexers and configured to control the plurality of multiplexers to select the output electrical signals;

a plurality of gate lines each electrically connected to a third gate electrode of a third thin film transistor of the plurality of driving circuits arranged along the second direction; and

a gate driving circuit electrically connected to the plurality of gate lines and configured to provide the readout instruction signal.

The fingerprint identification module of claim 13, further comprising:

a plurality of gate driving circuits each configured to provide the readout instruction signal;

a plurality of sets of gate lines each including a plurality of gate lines electrically connected to the plurality of gate driving circuits in a one-to-one correspondence, wherein each of the plurality of gate lines is electrically connected to a third gate of a third thin film transistor of the plurality of driving circuits arranged along the first direction; and

a plurality of data signal lines each of which is electrically connected to third drain electrodes of third thin film transistors of the plurality of driving circuits arranged along the second direction.

A display device, comprising: the fingerprint identification module of any one of claims 1 to 15.

The display device according to claim 16, further comprising:

a display module set,

wherein, the area of display module assembly with the area of fingerprint identification module assembly is roughly the same.

A driving method for the fingerprint recognition module according to any one of claims 1 to 15, comprising:

applying a driving voltage to a driving electrode to drive a portion of a piezoelectric material layer corresponding to the driving electrode to emit ultrasonic waves; and

and receiving the ultrasonic waves reflected by the fingerprints by using the piezoelectric material layer and outputting corresponding fingerprint electric signals through a receiving electrode.

The method for driving a fingerprint recognition module of claim 18, wherein the plurality of driving electrodes comprises a first driving electrode and a second driving electrode, the method comprising:

applying a driving voltage to the first driving electrode at a first time point to drive a portion of the piezoelectric material layer corresponding to the first driving electrode to emit an ultrasonic wave; and

applying a driving voltage to the second driving electrode at a second time point to delay a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the second driving electrode from a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the first driving electrode,

wherein the second time point is delayed from the first time point.

The method for driving a fingerprint recognition module of claim 19, wherein the plurality of driving electrodes further includes a third driving electrode, the second driving electrode is located between the first driving electrode and the third driving electrode, and the method comprises:

applying a driving voltage to the first driving electrode and the third driving electrode at a first time point to drive portions of the piezoelectric material layer corresponding to the first driving electrode and the third driving electrode to emit ultrasonic waves; and

applying a driving voltage to the second driving electrode at a second time point to delay a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the second driving electrode from a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the first driving electrode and the third driving electrode.

The driving method of the fingerprint identification module according to claim 19 or 20, wherein receiving the ultrasonic wave reflected by the fingerprint by the piezoelectric material layer and outputting the corresponding fingerprint electric signal through the receiving electrode comprises:

and turning on the receiving electrode corresponding to the second driving electrode according to the reflected echo time of the second driving electrode so as to receive the reflected echo.

The driving method of the fingerprint recognition module of claim 18, wherein the fingerprint recognition module further comprises: a plurality of drive circuits, each drive circuit electrically connected to one of the receiving electrodes, each drive circuit comprising: a storage capacitor including a first pole and a second pole; a first thin film transistor including a first gate electrode, a first source electrode, and a first drain electrode; and a signal reading sub-circuit, the receiving electrode, the first source electrode and the first pole being connected to a storage node, wherein receiving the ultrasonic wave reflected by the fingerprint using the piezoelectric material layer and outputting a corresponding fingerprint electrical signal through the receiving electrode comprises:

when a driving voltage is applied to the driving electrode to drive a part of the piezoelectric material layer corresponding to the driving electrode to emit ultrasonic waves, applying a turn-on signal to the first gate electrode to turn on the first thin film transistor;

applying bias voltage to the first drain electrode according to the arrival time of the surface echo so as to lift the fingerprint electric signal on the receiving electrode, and storing the lifted fingerprint electric signal in the storage capacitor; and

and reading out the fingerprint electric signal after being lifted by using the signal reading sub-circuit.

The driving method of a fingerprint recognition module of claim 18, wherein the driving voltage is applied to 8 to 10 driving electrodes during the application of the driving voltage to the driving electrodes.

A manufacturing method of a fingerprint identification module comprises the following steps:

providing a substrate;

forming a receiving electrode layer on one side of the substrate, the receiving electrode layer including a plurality of receiving electrodes arranged in an array along a first direction and a second direction;

forming a piezoelectric material layer on one side of the receiving electrode layer far away from the substrate; and

forming a driving electrode layer on a side of the piezoelectric material layer away from the receiving electrode layer, the driving electrode layer including a plurality of driving electrodes arranged in the second direction,

each driving electrode is a strip electrode extending along the first direction and is overlapped with the plurality of receiving electrodes arranged along the first direction.

The method for manufacturing a fingerprint identification module according to claim 24, wherein the forming of the driving electrode layer on the side of the piezoelectric material layer away from the receiving electrode layer comprises:

forming a plurality of first sub-driving electrodes through a patterning process, wherein each first sub-driving electrode is a strip-shaped sub-electrode extending along the first direction;

forming a retaining wall between the adjacent first sub-driving electrodes; and

forming a plurality of second sub-driving electrodes which are arranged corresponding to the plurality of first sub-driving electrodes one to one on one side of the plurality of first sub-driving electrodes far away from the substrate through an electroplating process,

the height of the retaining wall in the direction perpendicular to the driving electrode layer is larger than that of the first sub-driving electrodes in the direction perpendicular to the driving electrode layer, and the plurality of first sub-driving electrodes and the plurality of second sub-driving electrodes form the plurality of driving electrodes.