CN109244108B - OLED display substrate, manufacturing method thereof and OLED display device - Google Patents

Abstract

The embodiment of the invention provides an OLED display substrate, a manufacturing method thereof and an OLED display device, wherein the OLED display substrate comprises: the substrate base plate, set up OLED device layer and the encapsulation layer that is used for encapsulating OLED device layer on the substrate base plate still include: a piezoelectric functional layer; the piezoelectric functional layer is arranged on one side of the packaging layer far away from the substrate and used for generating mechanical vibration under the action of an electric signal so as to generate ultrasonic waves or audible sound waves. According to the embodiment of the invention, the piezoelectric functional layer is arranged in the OLED display substrate, the ultrasonic wave and the audible sound wave are generated through the mechanical vibration of the piezoelectric functional layer, the screen sounding and fingerprint identification functions are realized by adopting the same structure, the occupied volume of the OLED display is reduced, and the requirement of the OLED display on lightness and thinness is met.

Description

An OLED display substrate and a manufacturing method thereof, and an OLED display device

technical field

Embodiments of the present invention relate to the field of display technology, and in particular, to an OLED display substrate, a manufacturing method thereof, and an OLED display device.

Background technique

Organic Light-Emitting Device (OLED) display is a kind of display different from traditional liquid crystal display (LCD), which has active light-emitting, good temperature characteristics, low power consumption, fast response, and high reliability. The advantages of bending, ultra-thin and low cost. Therefore, it has become one of the important development discoveries of a new generation of display devices, and has received more and more attention.

In the OLED display, the piezoelectric driver is used to realize the screen sound function, and the ultrasonic sensor is used to realize the fingerprint recognition function. The inventor found that if the OLED display wants to realize the screen sound function and the fingerprint identification function at the same time, the piezoelectric driver and the ultrasonic sensor need to be set at the same time, so that the The volume occupied by the OLED display is relatively large, which cannot meet the requirement of thinning and lightening of the OLED display.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the embodiments of the present invention provide an OLED display substrate, a manufacturing method thereof, and an OLED display device. The same structure provided in the OLED display substrate is used to realize the functions of screen sound and fingerprint recognition, thereby reducing the occupation of the OLED display. The volume satisfies the demand for thin and light OLED displays.

In a first aspect, an embodiment of the present invention provides an OLED display substrate, comprising: a substrate substrate, an OLED device layer disposed on the substrate substrate, and an encapsulation layer for encapsulating the OLED device layer, the OLED display substrate The substrate further includes: a piezoelectric functional layer;

The piezoelectric functional layer is disposed on the side of the encapsulation layer away from the base substrate, and is used for generating mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves.

Optionally, the piezoelectric functional layer includes: a first electrode, a piezoelectric layer and a second electrode;

the piezoelectric layer is disposed between the first electrode and the second electrode;

The first electrode is disposed on a side of the piezoelectric layer close to the base substrate or a side away from the base substrate.

Optionally, the first electrode includes: first sub-electrodes arranged in an M×N array, and the piezoelectric layer includes: a piezoelectric structure arranged in an M×N array;

The orthographic projection of the first electrode on the base substrate coincides with the orthographic projection of the piezoelectric layer on the base substrate, wherein M and N are positive integers.

Optionally, the second electrode includes: second sub-electrodes arranged in an M×N array;

The orthographic projection of the first electrode on the base substrate coincides with the orthographic projection of the second electrode on the base substrate.

Optionally, the second electrode includes: a planar electrode;

The orthographic projection of the second electrode on the base substrate covers the orthographic projection of the first electrode on the base substrate.

Optionally, the first electrode and the second electrode are transparent electrodes, the materials of which include: indium tin oxide, nanotubes or graphene;

The fabrication material of the piezoelectric layer includes: polyvinylidene fluoride.

Optionally, the OLED display substrate further includes: a buffer layer, the buffer layer is disposed between the encapsulation layer and the piezoelectric functional layer; and/or

and a protective layer, the protective layer is disposed on the side of the piezoelectric functional layer away from the base substrate.

Optionally, the OLED display substrate further includes: a driving detection circuit, a first wire and a second wire; the driving detection circuit includes: a driving sub-circuit, a detection sub-circuit, a first switch and a second switch;

The driving sub-circuit is connected with the first sub-electrode and the first switch, and is used for generating a first electrical signal. When the first switch is in a closed state, it drives the piezoelectric structure to generate mechanical vibration to generate ultrasonic waves; for generating a second electrical signal, when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration to generate audible sound waves;

The detection sub-circuit is connected to the second sub-electrode and the second switch, and is used to form a fingerprint image according to the received ultrasonic wave reflected by the fingerprint when the second switch is in a closed state;

Wherein, each first sub-electrode is connected to the driving sub-circuit through a first wire, and each second sub-electrode is connected to the detection sub-circuit through a second wire.

Optionally, the OLED display substrate further includes: a driving detection circuit, a first wire and a second wire; the driving detection circuit includes: a driving sub-circuit, a detection sub-circuit, a first switch and a second switch;

The driving sub-circuit is connected with the first sub-electrode and the first switch, and is used for generating a first electrical signal. When the first switch is in a closed state, it drives the piezoelectric structure to generate mechanical vibration to generate ultrasonic waves; for generating a second electrical signal, when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration to generate audible sound waves;

The detection sub-circuit is connected to the first sub-electrode and the second switch, and is used to form a fingerprint image according to the received ultrasonic wave reflected by the fingerprint when the second switch is in a closed state;

Wherein, each first sub-electrode is connected to the driving sub-circuit through a first wire, and is connected to the detection sub-circuit through a second wire.

Optionally, the first wires are arranged on the same layer as the first electrodes, and the second wires are arranged on the same layer as the second electrodes.

In a second aspect, an embodiment of the present invention further provides an OLED display device, comprising: the above-mentioned OLED display substrate.

In a third aspect, an embodiment of the present invention further provides a method for fabricating an OLED display substrate, including:

providing a base substrate;

forming an OLED device layer on the base substrate;

forming an encapsulation layer on the OLED device layer for encapsulating the OLED device layer;

A piezoelectric functional layer is formed on the encapsulation layer, wherein the piezoelectric encapsulation layer is used to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves.

Optionally, the forming a piezoelectric functional layer on the encapsulation layer includes:

A first electrode, a piezoelectric layer and a second electrode are formed on the encapsulation layer to form a piezoelectric functional layer, wherein the piezoelectric layer is disposed between the first electrode and the second electrode.

Optionally, forming the piezoelectric layer includes:

Coating an insulating film, and forming a piezoelectric channel through an exposure and development process;

A piezoelectric layer is formed in the piezoelectric channel by an inkjet printing process.

Optionally, before forming the piezoelectric functional layer on the encapsulation layer, the method further includes:

forming a buffer layer on the encapsulation layer;

After forming the piezoelectric functional layer on the encapsulation layer, the method further includes:

A protective layer is formed on the piezoelectric functional layer.

Embodiments of the present invention provide an OLED display substrate, a manufacturing method thereof, and an OLED display device, wherein the OLED display substrate includes: a substrate substrate, an OLED device layer disposed on the substrate substrate, and an encapsulation layer for encapsulating the OLED device layer , and also includes: a piezoelectric functional layer; the piezoelectric functional layer is arranged on the side of the packaging layer away from the base substrate, and is used to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves. In the embodiment of the present invention, the piezoelectric functional layer is arranged in the OLED display substrate, and ultrasonic waves and audible sound waves are generated through its mechanical vibration, and the screen sounding and fingerprint recognition functions are realized by the same structure, which reduces the volume occupied by the OLED display and satisfies the requirements of the light and thin OLED display. ization needs.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the description, claims and drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. They are used to explain the technical solutions of the present invention together with the embodiments of the present application, and do not limit the technical solutions of the present invention.

FIG. 1 is a schematic structural diagram 1 of an OLED display substrate provided by an embodiment of the present invention;

2 is a schematic structural diagram of a piezoelectric functional layer provided by an embodiment of the present invention;

FIG. 3 is a side view 1 of an OLED display substrate provided by an embodiment of the present invention;

4 is a side view of a first electrode provided by an embodiment of the present invention;

5 is a top view of a piezoelectric layer provided by an embodiment of the present invention;

6 is a top view 1 of a second electrode provided by an embodiment of the present invention;

7 is a second side view of an OLED display substrate provided by an embodiment of the present invention;

FIG. 8 is a second top view of the second electrode provided by the embodiment of the present invention;

FIG. 9 is a second structural schematic diagram of an OLED display substrate provided by an embodiment of the present invention;

10 is a perspective view 1 of an OLED display substrate provided by an embodiment of the present invention;

FIG. 11 is an equivalent circuit diagram of the OLED display substrate corresponding to FIG. 10;

12 is a second oblique view of an OLED display substrate provided by an embodiment of the present invention;

FIG. 13 is an equivalent circuit diagram of the OLED display substrate corresponding to FIG. 12;

14 is a flowchart of a method for manufacturing an OLED display substrate provided by an embodiment of the present invention;

15A is a schematic diagram 1 of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

15B is a second schematic diagram of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

15C is a schematic diagram 3 of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

15D is a schematic diagram 4 of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

15E is a schematic diagram 5 of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

15F is a schematic diagram 6 of a method for fabricating an OLED display substrate according to an embodiment of the present invention;

FIG. 15G is a schematic diagram 7 of a method for fabricating an OLED display substrate according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, the embodiments in the present application and the features in the embodiments may be arbitrarily combined with each other if there is no conflict.

The steps shown in the flowcharts of the figures may be performed in a computer system, such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in an order different from that herein.

Unless otherwise defined, technical or scientific terms used in the disclosure of the embodiments of the present invention shall have the ordinary meanings understood by those with ordinary skill in the art to which the present invention belongs. "First", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Comprising" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right", etc. are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

Example 1

FIG. 1 is a first structural schematic diagram of an OLED display substrate provided by an embodiment of the present invention. As shown in FIG. 1 , an embodiment of the present invention provides an OLED display substrate, including: a base substrate 10 and an OLED disposed on the base substrate 10 The device layer 20 and the encapsulation layer 30 for encapsulating the OLED device layer 20 , and the OLED display substrate further includes: a piezoelectric functional layer 40 .

Specifically, the piezoelectric functional layer 40 is disposed on the side of the encapsulation layer 30 away from the base substrate 10 to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves.

Optionally, the manufacturing material of the base substrate 10 includes: glass, plastic, quartz, polyimide, etc., which is not limited in this embodiment of the present invention.

Specifically, the OLED device layer 20 includes: a thin film transistor and an anode, a light-emitting layer and a cathode disposed on the thin film transistor, wherein the thin film transistor includes: a gate electrode, a gate insulating layer, an active layer, an interlayer dielectric layer and a source-drain electrode , the drain electrode of the thin film transistor is connected to the anode.

Optionally, the thin film transistor may have a top-gate structure or a bottom-gate structure, which is not limited in this embodiment of the present invention.

Optionally, the material for making the encapsulation layer 30 includes: tetrafluoroethylene, which is used to protect the OLED device layer from being damaged.

In this embodiment, the piezoelectric functional layer 40 is used to generate mechanical vibration under the action of an electrical signal, so as to generate ultrasonic waves or audible sound waves. Among them, the mechanical vibration of the piezoelectric functional layer is used as the excitation source for the sound of the screen, and then the piezoelectric functional layer generates audible sound waves, which can realize the function of the sound of the screen, wherein the sound of the screen includes: full-screen sound and/or earpiece sound; pressure The electrical function layer generates ultrasonic waves, and the purpose of fingerprint recognition can be achieved by setting the circuit structure to identify the ultrasonic signals reflected by the fingerprint.

In addition, the piezoelectric functional layer 40 can also realize touch detection in combination with touch feedback, so as to improve user experience.

The OLED display substrate provided by the embodiment of the present invention includes: a substrate substrate, an OLED device layer disposed on the substrate substrate, and an encapsulation layer for encapsulating the OLED device layer, and further includes: a piezoelectric functional layer; the piezoelectric functional layer is disposed on the The side of the encapsulation layer away from the base substrate is used to generate mechanical vibrations under the action of electrical signals to generate ultrasonic waves or audible sound waves. In the embodiment of the present invention, the piezoelectric functional layer is arranged in the OLED display substrate, and ultrasonic waves and audible sound waves are generated through its mechanical vibration, and the screen sounding and fingerprint recognition functions are realized by the same structure, which reduces the volume occupied by the OLED display and satisfies the requirements of the light and thin OLED display. ization needs.

Optionally, FIG. 2 is a schematic structural diagram of a piezoelectric functional layer provided by an embodiment of the present invention. As shown in FIG. 2 , the piezoelectric functional layer 40 provided by an embodiment of the present invention includes: a first electrode 41 , a piezoelectric layer 42 and The second electrode 43 .

The piezoelectric layer 42 is disposed between the first electrode 41 and the second electrode 43 , and the first electrode 41 is disposed on the side of the piezoelectric layer 42 close to the base substrate 10 or the side away from the base substrate 10 .

Optionally, in order not to affect the display effect of the OLED display substrate, the first electrode 41 is a transparent electrode, the material of which includes transparent conductive materials such as indium tin oxide, carbon nanotubes, or graphene.

Optionally, the piezoelectric layer 42 is made of a piezoelectric material, wherein the piezoelectric material includes: polyvinylidene fluoride, polyvinylidene fluoride, aluminum nitride AlN, or lead zirconate titanate-based perovskite structure composite oxides, etc.

Preferably, in order to realize the flexible display substrate, the material for making the piezoelectric layer 42 includes: polyvinylidene fluoride.

Optionally, in order not to affect the display effect of the OLED display substrate, the second electrode 43 is a transparent electrode, the material of which includes transparent conductive materials such as indium tin oxide and carbon nanotubes.

It should be noted that, the first electrode 41 and the second electrode 43 may be made of the same or different materials, which are not limited in this embodiment of the present invention.

Specifically, the positions of the first electrode 41 and the second electrode 43 are not limited in this embodiment of the present invention, that is, the first electrode 41 may be disposed on the side of the piezoelectric layer 42 close to the base substrate 10, and the second The electrode 43 is arranged on the side of the piezoelectric layer 42 away from the base substrate 10 , the first electrode 41 can also be arranged at the side of the piezoelectric layer 42 away from the base substrate 10 , and the second electrode 43 is arranged on the side of the piezoelectric layer 42 close to the base substrate 10 . One side of the base substrate 10 .

Optionally, as an implementation manner, FIG. 3 is a side view 1 of an OLED display substrate provided by an embodiment of the present invention, FIG. 4 is a side view of a first electrode provided by an embodiment of the present invention, and FIG. 5 is an embodiment of the present invention Figure 6 is a top view of the second electrode provided by the embodiment of the present invention. As shown in Figures 3-6, the first electrode 41 in the OLED display substrate provided by the embodiment of the present invention includes: M The first sub-electrodes 410 arranged in a ×N array, the piezoelectric layer 42 includes: piezoelectric structures 420 arranged in an M×N array, and the second electrode 43 includes: second sub-electrodes 430 arranged in an M×N array.

Specifically, the orthographic projection of the first electrode 41 on the base substrate 10 coincides with the orthographic projection of the piezoelectric layer 42 on the base substrate 10 , and the orthographic projection of the first electrode 41 on the base substrate 10 coincides with that of the second electrode 43 The orthographic projections on the base substrate 10 overlap, that is, the first sub-electrodes 410 , the piezoelectric structures 420 and the second sub-electrodes 430 are in one-to-one correspondence. In this embodiment, the corresponding first sub-electrodes 410 and the piezoelectric structures 420 are And the second sub-electrode 430 becomes a vibration unit, that is to say, the piezoelectric functional layer provided in the embodiment of the present invention includes: an M×N array of vibration units.

It should be noted that, FIG. 3 to FIG. 6 are described by taking M=3 and N=3 as an example, which is not limited in this embodiment of the present invention.

Specifically, when a voltage signal is applied to the first sub-electrode 410 and the second sub-electrode 430, the piezoelectric structure 420 will generate mechanical vibration, and when the voltage signals applied to the first sub-electrode 410 and the second sub-electrode 430 are different , the intensity of the mechanical vibrations generated by the piezoelectric structure will vary.

Among them, M and N are positive integers. It should be noted that M is greater than or equal to 1, and N is greater than or equal to 1. When M=N=1, the OLED display substrate can only achieve full-screen sound, but cannot achieve earpiece sound. When M and N are different from 1, the OLED display panel can not only realize full-screen sound, but also can realize the earpiece sound. Specifically, the OLED display substrate can realize the earpiece sound by only adjusting the mechanical vibration of the vibration unit near the earpiece position. The OLED display substrate can also achieve full-screen sound through the mechanical vibration of all vibration units.

Optionally, as another implementation manner, FIG. 7 is a second side view of an OLED display substrate provided by an embodiment of the present invention, and FIG. 8 is a second top view of a second electrode provided by an embodiment of the present invention, as shown in FIGS. 4 and 5 . , as shown in FIG. 7 and FIG. 8 , the first electrode 41 in the OLED display substrate provided by the embodiment of the present invention includes: the first sub-electrodes 410 arranged in an M×N array, and the piezoelectric layer 42 includes: In the piezoelectric structure 420, the second electrode 43 includes: a planar electrode.

Specifically, the orthographic projection of the first electrode 41 on the base substrate 10 coincides with the orthographic projection of the piezoelectric layer 42 on the base substrate 10; specifically, the orthographic projection of the second electrode 43 on the base substrate 10 covers the first An orthographic projection of an electrode 41 on the base substrate 10 .

In addition, it should be noted that when the second electrode 43 is a planar electrode, the second electrode is grounded.

Optionally, FIG. 9 is a second structural schematic diagram of an OLED display substrate provided by an embodiment of the present invention. As shown in FIG. 9 , the OLED display substrate provided by an embodiment of the present invention further includes: a buffer layer 50 .

Specifically, the buffer layer 50 is disposed between the encapsulation layer 30 and the piezoelectric functional layer 40; it is used to avoid damage to the encapsulation layer during the fabrication of the piezoelectric functional layer, and can improve the reliability of the OLED display substrate.

Optionally, the fabricating material of the buffer layer 50 includes: silicon oxide, silicon nitride, or a composite of silicon oxide and silicon nitride, which is not limited in this embodiment of the present invention.

Optionally, as shown in FIG. 9 , the OLED display substrate provided by the embodiment of the present invention further includes: a protective layer 60 .

Specifically, the protective layer 60 is disposed on the side of the piezoelectric functional layer 40 away from the base substrate 10 to protect the piezoelectric functional layer from being damaged, which can also improve the reliability of the OLED display substrate.

Optionally, the manufacturing material of the protective layer 60 includes: silicon oxide, silicon nitride, or a composite of silicon oxide and silicon nitride, which is not limited in this embodiment of the present invention.

It should be noted that, FIG. 9 is illustrated by taking an example that the OLED display substrate includes a buffer layer and a protective layer at the same time.

Optionally, as an implementation manner, when the second electrode 43 includes the second sub-electrodes 430 arranged in an array, FIG. 10 is a first oblique view of the OLED display substrate provided by the embodiment of the present invention, and FIG. 11 is the corresponding view of FIG. 10 The equivalent circuit diagram of the OLED display substrate, as shown in FIG. 10 and FIG. 11 , the OLED display substrate provided by the embodiment of the present invention further includes: a drive detection circuit 70, a first wire L1 and a second wire L2; the drive detection circuit 70 includes: The driving sub-circuit 71, the detection sub-circuit 72, the first switch SW1 and the second switch SW2.

Specifically, the driving sub-circuit 71 is connected to the first sub-electrode 410 and the first switch SW1, and is used to generate a first electrical signal. When the first switch SW1 is in a closed state, the piezoelectric structure 420 is driven to generate mechanical vibration to generate a mechanical vibration. Ultrasonic; the driving sub-circuit 71 is also used to generate a second electrical signal, when the first switch SW1 is in a closed state, the piezoelectric structure 420 is driven to generate mechanical vibration to generate audible sound waves; the detection sub-circuit 72 is connected to the second sub-electrode 430 is connected to the second switch SW2, and is used to form a fingerprint image according to the received ultrasonic waves reflected by the fingerprint when the second switch SW2 is in a closed state.

Wherein, each first sub-electrode 410 is connected to the driving sub-circuit 71 through a first wire L1, and each second sub-electrode 430 is connected to the detection sub-circuit 72 through a second wire L2.

Specifically, as shown in FIG. 11 , the first terminal of the first switch SW1 is connected to the ground terminal GND, the second terminal of the first switch SW1 is connected to the first sub-electrode 410 and the driving sub-circuit 71 respectively, and the first terminal of the second switch SW2 is connected to the ground terminal GND. The ground terminal GND is connected, and the second terminal thereof is connected to the second sub-electrode 430 and the detection sub-circuit 72 respectively.

Specifically, the first wire L1 and the first electrode 41 are arranged in the same layer, and the second wire L2 and the second electrode 43 are arranged in the same layer. It should be noted that the arrangement of the two structures in the same layer means that the two structures use the same material and the same layer. Process formed.

It should be noted that FIG. 11 is illustrated by taking a connection circuit diagram of one vibration unit as an example, and the connection manner of each vibration unit in the piezoelectric structure layer is the same as that of FIG. 11 .

Optionally, as another implementation manner, FIG. 12 is a second oblique view of the OLED display substrate provided by the embodiment of the present invention, and FIG. 13 is an equivalent circuit diagram of the OLED display substrate corresponding to FIG. 12 , as shown in FIGS. 12 and 13 . As shown, it also includes: a driving detection circuit 70, a first wire L1 and a second wire L2; the driving detection circuit 70 includes: a driving sub-circuit 71, a detection sub-circuit 72, a first switch SW1 and a second switch SW2.

Specifically, the driving sub-circuit 71 is connected to the first sub-electrode 410 and the first switch SW1, and is used to generate a first electrical signal. When the first switch SW1 is in a closed state, the piezoelectric structure 420 is driven to generate mechanical vibration to generate a mechanical vibration. Ultrasonic; the driving sub-circuit 71 is also used to generate a second electrical signal, when the first switch SW1 is in a closed state, the piezoelectric structure 420 is driven to generate mechanical vibration to generate audible sound waves; the detection sub-circuit 72 is connected to the first sub-electrode 410 is connected to the second switch SW2 for forming a fingerprint image according to the received ultrasonic wave reflected by the fingerprint when the second switch SW2 is in a closed state.

Wherein, each first sub-electrode 410 is connected to the driving sub-circuit 71 through the first wire L1, and is connected to the detection sub-circuit 72 through the second wire L2.

Specifically, as shown in FIG. 13 , the first end of the first switch SW1 is connected to the ground terminal GND and the first sub-electrode 410 respectively, the second end of the first switch SW1 is connected to the driving sub-circuit 71 , and the first end of the second switch SW2 is respectively It is connected to the ground terminal GND and the second sub-electrode 430 , and the second end thereof is connected to the detection sub-circuit 72 .

It should be noted that, FIG. 13 takes a first sub-electrode, its corresponding piezoelectric structure, and a connection circuit diagram of a portion of the second electrode corresponding to the first sub-electrode as an example for illustration.

Specifically, the first wire L1 and the second wire L2 are provided in the same layer as the first electrode 41 .

The working principle of the OLED display substrate provided by the embodiment of the present invention is further described below with reference to FIG. 11 and FIG. 13 , specifically:

When the driving sub-circuit 71 generates the first electrical signal, the fingerprint recognition function is realized. Specifically, in the first stage, the driving sub-circuit 71 generates the first electrical signal, the first switch SW1 is in a closed state, and the second switch SW2 is in an open state , at this time, the signal of the first sub-electrode 410 is the first electrical signal; in the second stage, the first switch SW1 is in an open state, and the second switch SW2 is in a closed state, at this time, the signal of the first sub-electrode 410 still remains The first electrical signal, the signal of the second sub-electrode 430 is a ground signal, and the piezoelectric structure 420 generates mechanical vibration under the driving of the first electrical signal to generate ultrasonic waves; when the fingerprint presses the OLED display substrate, the generated ultrasonic waves are reflected by the fingerprint Back, the detection sub-circuit receives the ultrasonic wave reflected by the fingerprint to form a fingerprint image.

Specifically, when the fingerprint recognition function is realized, the ultrasonic wave reflected by the fingerprint will cause the change of the potential of the first sub-electrode and the second sub-electrode, and the detection sub-circuit will perform a change in the potential of the first sub-electrode and the second sub-electrode according to the change of the potential of the first sub-electrode and the second sub-electrode. Analyze and process to obtain fingerprint image.

In addition, the OLED display substrate provided in this embodiment can also realize touch detection. When the touch detection is realized, the detection sub-circuit only needs to detect the position where the electrical signal changes due to the ultrasonic wave reflected by the fingerprint. The position is the position of the touch to be detected.

When the driving sub-circuit 71 generates the second electrical signal, the screen sounds. Specifically, the first switch SW1 is in an open state, the second switch SW2 is in a closed state, and the signal of the first sub-electrode 410 is the second electric signal, so that The piezoelectric structure 420 generates mechanical vibration to generate audible sound waves, wherein the range of the audible sound waves is 20-20000 Hz. Specifically, when the first switch SW1 connected to the piezoelectric structure located near the earpiece is in an on state, and the first switch SW1 connected to the piezoelectric structure at other positions is in an off state, that is to say, at this time, the driving sub-circuit 71 only controls the piezoelectric structure near the position of the earpiece, and the OLED display substrate realizes the sound of the earpiece; when the first switch SW1 connected to all the piezoelectric structures in the OLED display substrate is in the open state, and the second switch SW2 is in the closed state, at this time, The driving sub-circuit 71 can control all piezoelectric structures, and the OLED display substrate realizes full-screen sound.

Embodiment 2

Based on the inventive concept of the above-mentioned embodiment, an embodiment of the present invention further provides a method for manufacturing an OLED display substrate. FIG. 14 is a flowchart of the method for manufacturing an OLED display substrate provided by an embodiment of the present invention. As shown in FIG. 14 , the present invention The manufacturing method of the OLED display substrate provided by the embodiment specifically includes the following steps:

Step 100, providing a base substrate.

Optionally, the manufacturing material of the base substrate includes: glass, plastic, quartz, polyimide, etc., which is not limited in this embodiment of the present invention.

Step 200 , forming an OLED device layer on the base substrate.

Specifically, the OLED device layer includes: a thin film transistor and an anode, a light-emitting layer and a cathode disposed on the thin film transistor, wherein the thin film transistor includes: an active layer, a gate electrode, a gate insulating layer, an interlayer dielectric layer and a source-drain electrode, The drain electrode of the thin film transistor is connected to the anode.

Optionally, the thin film transistor may have a top-gate structure or a bottom-gate structure, which is not limited in this embodiment of the present invention.

Step 300 , forming an encapsulation layer for encapsulating the OLED device layer on the OLED device layer.

Optionally, the material for making the encapsulation layer includes: tetrafluoroethylene, which is used to protect the OLED device layer from being damaged.

Step 400 , forming a piezoelectric functional layer on the encapsulation layer.

Among them, the piezoelectric packaging layer is used to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves.

In this embodiment, the piezoelectric functional layer is used to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves, and the piezoelectric functional layer generates audible sound waves, which can realize the function of screen sound, and the piezoelectric function The layer generates ultrasonic waves, and the purpose of fingerprint recognition can be achieved by setting the ultrasonic signal reflected by the fingerprint of the circuit structure.

In addition, the piezoelectric functional layer can also realize touch detection in combination with touch feedback, so as to increase user experience.

The manufacturing method of the OLED display substrate provided by the embodiment of the present invention includes: providing a base substrate; forming an OLED device layer on the base substrate; forming an encapsulation layer for encapsulating the OLED device layer on the OLED device layer; A piezoelectric functional layer is formed, wherein the piezoelectric encapsulation layer is used to generate mechanical vibration under the action of an electrical signal to generate ultrasonic waves or audible sound waves. In the embodiment of the present invention, the piezoelectric functional layer is arranged in the OLED display substrate, and ultrasonic waves and audible sound waves are generated through its mechanical vibration, and the screen sounding and fingerprint recognition functions are realized by the same structure, which reduces the volume occupied by the OLED display and satisfies the requirements of the light and thin OLED display. ization needs.

Optionally, step 400 specifically includes: forming a first electrode, a piezoelectric layer and a second electrode on the packaging layer to form a piezoelectric functional layer, wherein the piezoelectric layer is disposed between the first electrode and the second electrode.

Optionally, as an embodiment, step 400 may include: sequentially forming a first electrode, a piezoelectric layer and a second electrode on the encapsulation layer.

Optionally, as another implementation manner, step 400 may include: sequentially forming a second electrode, a piezoelectric layer and a first electrode on the encapsulation layer.

Optionally, in order not to affect the display effect of the OLED display substrate, the first electrode is a transparent electrode, and its fabrication material includes transparent conductive materials such as indium tin oxide, carbon nanotubes, or graphene.

Optionally, the piezoelectric layer is made of a piezoelectric material, wherein the piezoelectric material includes: a composite of polyvinylidene fluoride, polyvinylidene fluoride, aluminum nitride AlN, or a lead zirconate titanate-based perovskite structure oxides, etc.

Preferably, in order to realize the flexible display substrate, the piezoelectric layer is made of: polyvinylidene fluoride.

Optionally, in order not to affect the display effect of the OLED display substrate, the second electrode is a transparent electrode, and its fabrication material includes transparent conductive materials such as indium tin oxide and carbon nanotubes.

It should be noted that, the materials for making the first electrode and the second electrode may be the same or different, which is not limited in the embodiment of the present invention.

Specifically, the first electrode includes: first sub-electrodes arranged in an M×N array, the piezoelectric layer includes: piezoelectric structures arranged in an M×N array, and the second electrode includes: second sub-electrodes arranged in an M×N array, Or the second electrode includes: a planar electrode.

In this embodiment, the OLED display substrate further includes: a drive detection circuit, a first wire and a second wire, wherein the drive detection circuit includes a drive subcircuit, a detection subcircuit, a first switch and a second switch, and the drive subcircuit is connected with the first switch, and the second switch is connected with the detection sub-circuit.

Optionally, when the second electrode includes: sub-electrodes arranged in an array, forming the first electrode includes: forming a first electrode and a first wire, wherein the first sub-electrode is connected to the driving sub-circuit through the first wire; forming a first electrode The two electrodes include: forming a second electrode and a second wire, wherein the second sub-electrode is connected to the driving sub-circuit through the second wire.

Specifically, a first metal thin film is deposited by a plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical VaporDeposition, PECVD for short) process, a first electrode and a first wire are formed by a patterning process, a second metal thin film is deposited by a PECVD process, and a patterned The process forms a second electrode and a second wire.

It should be noted that the patterning process includes processes such as photoresist coating, exposure, development, etching, and photoresist stripping.

Optionally, when the second electrode includes: a planar electrode, forming the first electrode includes: forming a first electrode, a first wire and a second wire, wherein the first sub-electrode is connected to the driving sub-circuit through the first wire, The second wire is connected to the detection sub-circuit.

Specifically, the first metal thin film is deposited by a plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition, PECVD for short) process, and the first electrode, the first wire and the second wire are formed by a patterning process.

Optionally, in order to ensure the performance of the OLED display substrate, forming the piezoelectric layer includes: coating an insulating film, forming a piezoelectric channel through an exposure and developing process; and forming a piezoelectric layer in the piezoelectric channel through an inkjet printing process.

Optionally, an insulating film may be coated on the first electrode, and an insulating film may also be coated on the second electrode.

Optionally, the insulating film can be made of polyimide, silicon oxide, silicon nitride, or a composite of silicon oxide and silicon nitride.

Specifically, the thickness of the insulating film is equal to the sum of the thicknesses of the first electrode and the piezoelectric layer.

In this embodiment, the shape of the piezoelectric layer is ensured by the piezoelectric layer in the piezoelectric channel, and the piezoelectric material is not easily shaped when the piezoelectric layer is formed by the inkjet printing process, so that the adjacent piezoelectric structures are not easily shaped. The piezoelectric structure connection affects the screen sound and finger recognition functions of the OLED display substrate.

Optionally, before step 400, the manufacturing method of the OLED display substrate provided by the embodiment of the present invention further includes: forming a buffer layer on the encapsulation layer.

Optionally, the material for fabricating the buffer layer includes: silicon oxide, silicon nitride, or a composite of silicon oxide and silicon nitride, which is not limited in this embodiment of the present invention.

Optionally, after step 400, the manufacturing method of the OLED display substrate provided by the embodiment of the present invention further includes: forming a protective layer on the piezoelectric functional layer.

Optionally, a material for making the protective layer includes silicon oxide, silicon nitride, or a composite of silicon oxide and silicon nitride, which is not limited in this embodiment of the present invention.

The OLED display substrate provided by the embodiment of the present invention is further described below with reference to FIGS. 15A-15G , taking the first electrode disposed on the side of the piezoelectric layer close to the base substrate, and the second electrode including the second sub-electrodes arranged in an array as an example. production method.

Step 510 , forming the OLED device layer 20 and the encapsulation layer 30 on the base substrate 10 in sequence, as shown in FIG. 15A .

Step 520 , forming a buffer layer 50 on the encapsulation layer 30 , as shown in FIG. 15B .

Specifically, a buffer film is deposited on the encapsulation layer 30, and the buffer layer 50 is formed through a patterning process.

Step 530 , forming a first electrode and a first wire (not shown in the figure) including the first sub-electrodes 410 arranged in an array on the buffer layer 50 , as shown in FIG. 15C .

Step 540 , coating an insulating film 80 on the first electrode, and forming a groove 81 exposing the first sub-electrode 410 through an exposure and development process, as shown in FIG. 15D .

The thickness of the insulating film 80 is equal to the sum of the thicknesses of the first electrode and the piezoelectric layer.

Step 550 , forming a piezoelectric layer including the piezoelectric structures 420 arranged in an array in the groove 81 by an inkjet printing process, as shown in FIG. 15E .

Step 560 , forming a second electrode and a second wire (not shown in the figure) including the second sub-electrodes 430 arranged in an array on the piezoelectric layer, as shown in FIG. 15F .

Step 570 , forming a protective layer 60 on the second electrode, as shown in FIG. 15G .

Specifically, a protective film is deposited on the second electrode, and a protective layer is formed through a patterning process.

It should be noted that when the second electrode includes a planar electrode, the difference from the above method lies in step 530 and step 560 , and the corresponding step 530 is to form the first sub-electrode 410 including the first sub-electrodes 410 arranged in an array on the buffer layer 50 . An electrode, a first wire and a second wire, the corresponding step 560 is to form a planar electrode on the piezoelectric material, wherein the projection of the planar electrode on the base substrate covers the orthographic projection of the first electrode on the base substrate , and details are not described herein again in this embodiment of the present invention.

Embodiment 3

Based on the inventive concept of the above embodiments, the embodiments of the present invention further provide an OLED display device, including: an OLED display substrate.

The OLED display substrate is the OLED display substrate provided in the first embodiment, and its implementation principle and implementation effect are similar, which will not be repeated here.

Specifically, the OLED display device may be any product or component with a display function, such as an OLED panel, a mobile phone, a tablet computer, a TV, a monitor, a notebook computer, a digital photo frame, and a navigator.

The drawings of the embodiments of the present invention only relate to the structures involved in the embodiments of the present invention, and other structures may refer to general designs.

In the drawings used to describe embodiments of the invention, the thickness and dimensions of layers or microstructures are exaggerated for clarity. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element, Or intermediate elements may be present.

The embodiments of the present invention, ie, the features of the embodiments, may be combined with each other to obtain new embodiments without conflict.

Although the embodiments disclosed in the present invention are as above, the described contents are only the embodiments adopted to facilitate the understanding of the present invention, and are not intended to limit the present invention. Any person skilled in the art to which the present invention belongs, without departing from the spirit and scope disclosed by the present invention, can make any modifications and changes in the form and details of the implementation, but the scope of the patent protection of the present invention must still be The scope defined by the appended claims shall prevail.

Claims (15)

1. An OLED display substrate, comprising: the OLED display substrate comprises a substrate base plate, an OLED device layer arranged on the substrate base plate and an encapsulation layer used for encapsulating the OLED device layer, and further comprises: a piezoelectric functional layer;

the piezoelectric functional layer is arranged on one side, far away from the substrate base plate, of the packaging layer and used for generating mechanical vibration under the action of the first electric signal to generate ultrasonic waves and achieve a fingerprint identification function, and the piezoelectric functional layer is further used for generating mechanical vibration under the action of the second electric signal to generate audible sound waves and achieve full-screen sounding or earphone sounding.

2. The OLED display substrate of claim 1, wherein the piezoelectric functional layer comprises: a first electrode, a piezoelectric layer, and a second electrode;

the piezoelectric layer is disposed between the first electrode and the second electrode;

the first electrode is arranged on one side of the piezoelectric layer close to the substrate base plate or one side far away from the substrate base plate.

3. The OLED display substrate of claim 2, wherein the first electrode comprises: a first sub-electrode arranged in an M N array, the piezoelectric layer comprising: piezoelectric structures arranged in an M × N array;

and the orthographic projection of the first electrode on the substrate is superposed with the orthographic projection of the piezoelectric layer on the substrate, wherein M and N are positive integers.

4. The OLED display substrate of claim 3, wherein the second electrode comprises: a second sub-electrode arranged in an M × N array;

the orthographic projection of the first electrode on the substrate base plate is superposed with the orthographic projection of the second electrode on the substrate base plate.

5. The OLED display substrate of claim 3, wherein the second electrode comprises: a planar electrode;

the orthographic projection of the second electrode on the substrate covers the orthographic projection of the first electrode on the substrate.

6. The OLED display substrate of claim 2, wherein the first and second electrodes are transparent electrodes made of a material comprising: indium tin oxide, carbon nanotubes, or graphene;

the manufacturing material of the piezoelectric layer comprises: polyvinylidene fluoride.

7. The OLED display substrate of claim 1, further comprising: a buffer layer disposed between the encapsulation layer and the piezoelectric functional layer; and/or

The protective layer is arranged on one side, far away from the substrate base plate, of the piezoelectric functional layer.

8. The OLED display substrate of claim 4, further comprising: a drive detection circuit, a first wire and a second wire; the drive detection circuit includes: the driving sub-circuit, the detection sub-circuit, the first switch and the second switch;

the driving sub-circuit is connected with the first sub-electrode and the first switch and used for generating a first electric signal, and when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration so as to generate ultrasonic waves; the second switch is used for generating a second electric signal, and when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration so as to generate audible sound waves;

the detection sub-circuit is connected with the second sub-electrode and the second switch and is used for forming a fingerprint image according to the received ultrasonic waves reflected by the fingerprint when the second switch is in a closed state;

each first sub-electrode is connected with the driving sub-circuit through a first lead, and each second sub-electrode is connected with the detection sub-circuit through a second lead.

9. The OLED display substrate of claim 5, further comprising: a drive detection circuit, a first wire and a second wire; the drive detection circuit includes: the driving sub-circuit, the detection sub-circuit, the first switch and the second switch;

the driving sub-circuit is connected with the first sub-electrode and the first switch and used for generating a first electric signal, and when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration so as to generate ultrasonic waves; the second switch is used for generating a second electric signal, and when the first switch is in a closed state, the piezoelectric structure is driven to generate mechanical vibration so as to generate audible sound waves;

the detection sub-circuit is connected with the first sub-electrode and the second switch and is used for forming a fingerprint image according to the received ultrasonic waves reflected by the fingerprint when the second switch is in a closed state;

each first sub-electrode is connected with the driving sub-circuit through a first lead and connected with the detection sub-circuit through a second lead.

10. The OLED display substrate of claim 8, wherein the first conductive line is disposed on the same layer as the first electrode, and the second conductive line is disposed on the same layer as the second electrode.

11. An OLED display device, comprising: an OLED display substrate as claimed in any one of claims 1 to 10.

12. A manufacturing method of an OLED display substrate is characterized by comprising the following steps:

providing a substrate base plate;

forming an OLED device layer on the substrate base plate;

forming an encapsulation layer for encapsulating the OLED device layer on the OLED device layer;

and forming a piezoelectric functional layer on the packaging layer, wherein the piezoelectric functional layer is used for generating mechanical vibration under the action of a first electric signal to generate ultrasonic waves and realize a fingerprint identification function, and is also used for generating mechanical vibration under the action of a second electric signal to generate audible sound waves and realize full-screen sounding or earphone sounding.

13. The method of claim 12, wherein forming a piezoelectric functional layer on the encapsulation layer comprises:

forming a first electrode, a piezoelectric layer, and a second electrode on the encapsulation layer to form a piezoelectric functional layer, wherein the piezoelectric layer is disposed between the first electrode and the second electrode.

14. The method of claim 13, wherein forming the piezoelectric layer comprises:

coating an insulating film, and forming a piezoelectric channel through an exposure and development process;

a piezoelectric layer is formed in the piezoelectric channel by an inkjet printing process.

15. The method of claim 12, wherein prior to forming a piezoelectric functional layer on the encapsulation layer, the method further comprises:

forming a buffer layer on the encapsulation layer;

after the forming the piezoelectric functional layer on the encapsulation layer, the method further comprises:

forming a protective layer on the piezoelectric functional layer.

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