CN114300521A - Flexible display panel and manufacturing method thereof - Google Patents

Abstract

The present application provides a flexible display panel and a manufacturing method thereof. The flexible display panel includes a TFT substrate, an OLED substrate and an encapsulation layer. The TFT substrate includes a first flexible substrate, and a TFT layer disposed on the first flexible substrate. The OLED substrate includes a second flexible substrate, a first electrode disposed under the second flexible substrate, an OLED functional layer disposed under the first electrode, and a second electrode disposed under the OLED functional layer; the second electrode and the TFT layer connect. The encapsulation layer is arranged on the TFT substrate and the OLED substrate and surrounds the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate. That is, the upper and lower sides of the flexible display panel can block water and oxygen through the first flexible substrate and the second flexible substrate, so that the encapsulation layer only needs to surround the OLED substrate to block the invading water and oxygen from the sides, so the encapsulation layer can have The opening of the second flexible substrate is exposed, and the opening can release the bending stress of the encapsulation layer, so as to prevent the encapsulation layer from breaking, so that the encapsulation layer can effectively block water and oxygen.

Description

Flexible display panel and manufacturing method thereof

technical field

The present application relates to the technical field of display devices, and in particular, to a flexible display panel and a manufacturing method thereof.

Background technique

Electroluminescent diodes (OLEDs) have the advantages of simple preparation process, low cost, high luminous efficiency, easy formation of flexible structures, low power consumption, high color saturation, and wide viewing angles. important display technology.

An OLED is a current-type light-emitting device, which mainly includes an anode, a cathode, and an OLED functional layer. The main working principle of OLED is that the OLED functional layer emits light through carrier injection and recombination under the driving of the electric field formed by the anode and the cathode.

A flexible display panel in the prior art includes a flexible substrate, a TFT substrate disposed on the flexible substrate, a plurality of OLEDs disposed on the TFT substrate, and an encapsulation layer disposed on the TFT substrate and the plurality of OLEDs and covering the plurality of OLEDs . The flexible display panel needs to be rolled up or bent, or even bent frequently during use. However, with the increasing number of bending times, the encapsulation layer of the prior art cannot release stress during the bending process and is easily broken, resulting in the inability to effectively block water and oxygen.

SUMMARY OF THE INVENTION

The present application provides a flexible display panel and a manufacturing method thereof, so as to solve the problem that the encapsulation layer in the prior art cannot release stress during the bending process and is easily broken, resulting in the inability to effectively block water and oxygen.

In one aspect, the present application provides a flexible display panel, comprising:

a TFT substrate, the TFT substrate includes a first flexible substrate, and a TFT layer disposed on the first flexible substrate;

an OLED substrate, the OLED substrate is disposed above the TFT substrate, and the OLED substrate includes a second flexible substrate, a first electrode disposed under the second flexible substrate, and a first electrode disposed under the first electrode an OLED functional layer, and a second electrode disposed under the OLED functional layer; the second electrode is connected to the TFT layer;

An encapsulation layer, the encapsulation layer is disposed on the TFT substrate and the OLED substrate, and surrounds the periphery of the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate.

In some possible implementations, the first flexible substrate includes a first organic buffer layer, a first inorganic barrier layer disposed on the first organic buffer layer, and a first inorganic barrier layer disposed on the first inorganic barrier layer. A second organic buffer layer, and a second inorganic barrier layer disposed on the second organic buffer layer.

In some possible implementations, the first inorganic barrier layer and the second inorganic barrier layer are high temperature dense film layers.

In some possible implementations, the first inorganic barrier layer has a plurality of first through holes exposing the first organic buffer layer, and the second organic buffer layer is also filled in the plurality of first organic buffer layers. in the through hole.

In some possible implementations, the second flexible substrate includes a third organic buffer layer, a third inorganic barrier layer disposed under the third organic buffer layer, and a third inorganic barrier layer disposed under the third inorganic barrier layer a fourth organic buffer layer, and a fourth inorganic barrier layer disposed under the fourth organic buffer layer.

In some possible implementations, the third inorganic barrier layer and the fourth inorganic barrier layer are high temperature dense film layers.

In some possible implementations, the third inorganic barrier layer has a plurality of second through holes exposing the third organic buffer layer, and the fourth organic buffer layer is further filled in the plurality of second through holes. in the through hole.

In some possible implementations, the OLED substrate further includes a pixel definition layer disposed under the first electrode, and a protrusion portion disposed under the pixel definition layer;

The OLED functional layer is located in the pixel definition layer, the second electrode is located under the pixel definition layer, and the protrusion is located between the pixel definition layer and the second electrode.

In some possible implementation manners, the TFT substrate further includes a flat layer disposed on the TFT layer, and an overlap electrode disposed on the flat layer;

The flat layer has a via hole exposing the TFT layer, the overlapping electrode is connected to the TFT layer through the via hole, and the second electrode is connected to the overlapping electrode.

On the other hand, the present application also provides a manufacturing method of a flexible display panel, comprising:

providing a first carrier board, and fabricating a first flexible substrate on the first carrier board;

fabricating a TFT layer on the first flexible substrate to form a TFT substrate;

providing a second carrier board, and fabricating a second flexible substrate on the second carrier board;

forming a first electrode on the second flexible substrate, forming an OLED functional layer on the first electrode, forming a second electrode on the OLED functional layer, and peeling off the second carrier plate to form an OLED substrate;

aligning the TFT substrate with the OLED substrate, and connecting the second electrode with the TFT layer;

forming an encapsulation layer on the TFT substrate and the OLED substrate, the encapsulation layer surrounds the periphery of the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate;

Peel off the first carrier plate.

The flexible display panel provided by the present application includes a TFT substrate, an OLED substrate and an encapsulation layer. The TFT substrate includes a first flexible substrate, and a TFT layer disposed on the first flexible substrate. The OLED substrate is arranged above the TFT substrate, and the OLED substrate includes a second flexible substrate, a first electrode arranged under the second flexible substrate, an OLED functional layer arranged under the first electrode, and a first electrode arranged under the OLED functional layer. Two electrodes; the second electrode is connected with the TFT layer. The encapsulation layer is arranged on the TFT substrate and the OLED substrate and surrounds the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate. That is, in this application, the TFT layer and the OLED functional layer are respectively arranged on the first flexible substrate and the second flexible substrate, so that the upper and lower sides of the flexible display panel can block water and oxygen through the first flexible substrate and the second flexible substrate. , so that the encapsulation layer only needs to surround the OLED substrate to block the water and oxygen intruding from the side, and the encapsulation layer only surrounds the OLED substrate and does not need to cover the entire OLED substrate. Therefore, the encapsulation layer can have a second flexible lining exposed The opening at the bottom can release the bending stress of the encapsulation layer during the bending process of the flexible display panel, so as to prevent the encapsulation layer from breaking, so that the encapsulation layer can effectively block water and oxygen.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic diagram of a flexible display panel provided by an embodiment of the present application;

FIG. 2 is a top view of a flexible display panel provided by an embodiment of the present application;

3 is a cross-sectional view of a flexible display panel provided by an embodiment of the present application;

4 is a cross-sectional view of a flexible display panel provided by another embodiment of the present application;

FIG. 5 is a flowchart of a manufacturing method of a flexible display panel provided by an embodiment of the present application;

6 is a schematic diagram of steps S1-S2 of a method for manufacturing a flexible display panel provided by an embodiment of the present application;

7 is a schematic diagram of steps S3-S4 of a method for manufacturing a flexible display panel provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of step S1 of a method for fabricating a flexible display panel provided by another embodiment of the present application;

FIG. 9 is a schematic diagram of step S3 of a method for fabricating a flexible display panel provided by another embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation on this application. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present application, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be mechanical connection, electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, unless otherwise expressly specified and defined, a first feature "on" or "under" a second feature may include direct contact between the first and second features, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the application. Furthermore, this application may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments-and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIGS. 1 to 4 , an embodiment of the present application provides a flexible display panel, including:

TFT substrate 1, the TFT substrate 1 includes a first flexible substrate 11 and a TFT layer 12 disposed on the first flexible substrate 11;

The OLED substrate 2 is arranged above the TFT substrate 1 , and the OLED substrate 2 includes a second flexible substrate 21 , a first electrode 22 arranged under the second flexible substrate 21 , and an OLED arranged under the first electrode 22 . The functional layer 23, and the second electrode 24 disposed under the OLED functional layer 23; the second electrode 24 is connected to the TFT layer 12;

The encapsulation layer 3 is disposed on the TFT substrate 1 and the OLED substrate 2 and surrounds the OLED substrate 2 . The encapsulation layer 3 has an opening 301 exposing the second flexible substrate 21 .

It should be noted that the TFT layer 12 and the OLED functional layer 23 in the present application are not formed on the same substrate, but the TFT layer 12 and the OLED functional layer 23 are respectively provided on the first flexible substrate 11 and the second flexible substrate 21 On the top, two substrates are formed, so that the upper and lower sides of the flexible display panel can block water and oxygen through the first flexible substrate 11 and the second flexible substrate 21, so that the encapsulation layer 3 only needs to surround the OLED substrate 2 and block the sides. Invading water and oxygen, and the encapsulation layer 3 only surrounds the OLED substrate 2 and does not need to cover the entire surface of the OLED substrate 2. Therefore, the encapsulation layer 3 may have an opening 301 exposing the second flexible substrate 21. During the folding process, the opening 301 can release the bending stress of the encapsulation layer 3 , thereby preventing the encapsulation layer 3 from breaking, so that the encapsulation layer 3 can effectively block water and oxygen.

In addition, compared with the prior art in which the TFT layer 12 and the OLED functional layer 23 are formed on the same substrate, the present application sets the TFT layer 12 and the OLED functional layer 23 on the first flexible substrate 11 and the second flexible substrate 21 respectively. On the above, two substrates are formed, which can also improve the process yield.

The embodiments of the present application do not specifically limit the application of the flexible display panel, which may be a TV, a laptop, a tablet, a wearable display device (such as a smart bracelet, a smart watch, etc.), a mobile phone, a virtual reality device, an augmented reality Any product or component with display function, such as equipment, vehicle display, advertising light box, etc.

In some embodiments, referring to FIG. 2 , the encapsulation layer 3 only needs to surround the periphery of the OLED substrate 2 . Therefore, from a top view, the area of the opening 301 of the flexible display panel may be slightly smaller than the area of the second flexible substrate 21 . The area of the opening 301 of the flexible display panel is maximized to further reduce the stress when the encapsulation layer 3 is bent.

In some embodiments, referring to FIG. 1 , the encapsulation layer 3 may include two barrier layers 31 and a buffer layer 32 between the two barrier layers 31 . The blocking layer 31 is an inorganic material, and the buffer layer 32 is an organic material. Water and oxygen are blocked by the two barrier layers 31 , and the bending stress of the two barrier layers 31 is relieved by the buffer layer 32 , which further prevents the encapsulation layer 3 from breaking when it is bent.

In some embodiments, please refer to FIG. 3 and FIG. 4 , the light emitting direction of the flexible display panel may be the direction in which the OLED substrate 2 is away from the TFT substrate 1 , the second electrode 24 may be an anode, and the first electrode 22 may be a cathode.

The OLED functional layer 23 includes a hole injection layer, a hole transport layer, a light emitting layer and an electron transport layer which are stacked in sequence along the direction of the second electrode 24 being close to the first electrode 22 .

In some embodiments, please refer to FIG. 3 , the first flexible substrate 11 includes a first organic buffer layer 111 , a first inorganic barrier layer 112 disposed on the first organic buffer layer 111 , and a first inorganic barrier layer 112 The second organic buffer layer 113 on the second organic buffer layer 113 , and the second inorganic barrier layer 114 disposed on the second organic buffer layer 113 . The first inorganic barrier layer 112 and the second inorganic barrier layer 114 can block water and oxygen intruding from the lower side of the flexible display panel, and the first organic buffer layer 111 and the second organic buffer layer 113 can relieve the first inorganic barrier layer 112 and the second organic buffer layer 112. The bending stress of the inorganic barrier layer 114 prevents the first flexible substrate 11 from being broken during bending.

In this embodiment, the materials of the first inorganic barrier layer 112 and the second inorganic barrier layer 114 may be one or a combination of silicon nitride, silicon oxide, or silicon oxynitride. The material of the first organic buffer layer 111 and the second organic buffer layer 113 may be polyimide (PI), polyethylene terephthalate (PET) or polydimethylsiloxane (PDMS).

In this embodiment, the first inorganic barrier layer 112 and the second inorganic barrier layer 114 are high temperature dense film layers. The high temperature dense film layer refers to a dense film quality film layer formed by high temperature production. The dense film has excellent water and oxygen blocking ability, which can further improve the water and oxygen blocking ability of the first flexible substrate 11 . In addition, since the present application uses the first flexible substrate 11 and the second flexible substrate 21 to block the water and oxygen invading the upper and lower sides of the flexible display panel, the first flexible substrate 11 and the second flexible substrate 21 are used in the production of OLEDs. The functional layer 23 and the TFT layer 12 are prepared before. Therefore, the present application can use high temperature to make the first inorganic barrier layer 112 and the second inorganic barrier layer 114. For example, the first inorganic barrier layer can be fabricated at a temperature of 360-380° C. 112, to fabricate the second inorganic barrier layer 114 at a temperature of 420-440°C. The prior art mainly relies on the encapsulation layer 3 to block the water and oxygen invading the flexible display panel. The encapsulation layer 3 in the prior art is fabricated on the OLED substrate 2. Therefore, in order to avoid the failure of the OLED functional layer 23 caused by high temperature, the prior art The encapsulation layer 3 is made of a low-temperature film, for example, made at a temperature of 80-85° C., resulting in a relatively loose film quality and limited ability to block water and oxygen. Therefore, the ability of the first flexible substrate 11 of the present application to block water and oxygen is better than that of the encapsulation layer 3 in the prior art.

In some embodiments, referring to FIG. 4 , the first inorganic barrier layer 112 has a plurality of first through holes 1121 exposing the first organic buffer layer 111 , and the second organic buffer layer 113 is also filled in the plurality of first through holes 1121 . in hole 1121. The plurality of first through holes 1121 can further relieve the bending stress of the first inorganic barrier layer 112 when the first inorganic barrier layer 112 is bent, and prevent the first inorganic barrier layer 112 from breaking when the first inorganic barrier layer 112 is bent. In addition, the second organic buffer layer 113 is also filled in the plurality of first through holes 1121 , so that the second organic buffer layer 113 can further relieve the bending stress of the first inorganic barrier layer 112 .

In this embodiment, the second organic buffer layer 113 can also be connected to the first organic buffer layer 111 , so that the second organic buffer layer 113 and the first organic buffer layer 111 are in an integrated structure, which can further relieve the first inorganic barrier layer 112 and the bending stress of the second inorganic barrier layer 114 to prevent the first flexible substrate 11 from being broken during bending.

In this embodiment, the shape of the plurality of first through holes 1121 can be triangular, circular, rectangular or polygonal, so that the first inorganic barrier layer 112 is in the shape of a grid as a whole, or the shape of the plurality of first through holes 1121 It can be a long strip with both ends located at the edge of the first inorganic barrier layer 112 , so that the first inorganic barrier layer 112 is arranged in a plurality of strip structures as a whole.

In some embodiments, please refer to FIG. 3 , the second flexible substrate 21 includes a third organic buffer layer 211 , a third inorganic barrier layer 212 disposed under the third organic buffer layer 211 , and a third inorganic barrier layer 212 The fourth organic buffer layer 213 under the fourth organic buffer layer 213 , and the fourth inorganic barrier layer 214 disposed under the fourth organic buffer layer 213 . The third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 can block water and oxygen intruding from the upper side of the flexible display panel, and the third organic buffer layer 211 and the fourth organic buffer layer 213 can relieve the third inorganic barrier layer 212 and the fourth The bending stress of the inorganic barrier layer 214 prevents the second flexible substrate 21 from being broken during bending.

In this embodiment, the materials of the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 may be one or a combination of silicon nitride, silicon oxide, or silicon oxynitride. The materials of the third organic buffer layer 211 and the fourth organic buffer layer 213 may be polyimide (PI), polyethylene terephthalate (PET) or polydimethylsiloxane (PDMS).

In this embodiment, the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 are high temperature dense film layers. The high temperature dense film layer refers to a dense film quality film layer formed by high temperature production. The dense film has excellent water and oxygen blocking ability, which can further improve the water and oxygen blocking ability of the second flexible substrate 21 . In addition, since the present application uses the first flexible substrate 11 and the second flexible substrate 21 to block the water and oxygen invading the upper and lower sides of the flexible display panel, the first flexible substrate 11 and the second flexible substrate 21 are used in the production of OLEDs. The functional layer 23 and the TFT layer 12 are previously fabricated. Therefore, the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 can be fabricated at a high temperature in the present application. For example, the third inorganic barrier layer can be fabricated at a temperature of 360-380° C. 212, to fabricate the fourth inorganic barrier layer 214 at a temperature of 420-440°C. The prior art mainly relies on the encapsulation layer 3 to block the water and oxygen invading the flexible display panel. The encapsulation layer 3 in the prior art is fabricated on the OLED substrate 2. Therefore, in order to avoid the failure of the OLED functional layer 23 caused by high temperature, the prior art The encapsulation layer 3 is made of a low-temperature film, for example, made at a temperature of 80-85° C., resulting in a relatively loose film quality and limited ability to block water and oxygen. Therefore, the ability of the second flexible substrate 21 of the present application to block water and oxygen is better than that of the encapsulation layer 3 in the prior art.

In some embodiments, referring to FIG. 4 , the third inorganic barrier layer 212 has a plurality of second through holes 2121 exposing the third organic buffer layer 211 , and the fourth organic buffer layer 213 is also filled in the plurality of second through holes 2121 . hole 2121. The plurality of second through holes 2121 can further relieve the bending stress of the third inorganic barrier layer 212 when the third inorganic barrier layer 212 is bent, and prevent the third inorganic barrier layer 212 from breaking when the third inorganic barrier layer 212 is bent. In addition, the fourth organic buffer layer 213 is also filled in the plurality of second through holes 2121 , so that the fourth organic buffer layer 213 can further relieve the bending stress of the third inorganic barrier layer 212 .

In addition, the first inorganic barrier layer 112 may be a whole-layer structure or a structure with a plurality of first through holes 1121, and the third inorganic barrier layer 212 may be a whole-layer structure or a structure with a plurality of second through holes 2121, so it can be The structural settings of the first inorganic barrier layer 112 and the third inorganic barrier layer 212 are selected according to the situation, which is not limited in this application. For example, the first inorganic barrier layer 112 and the third inorganic barrier layer 212 both have a whole-layer structure, or the first inorganic barrier layer 112 has a structure with a plurality of first through holes 1121 , and the third inorganic barrier layer 212 has a structure with a plurality of first through holes 1121 . The structure of two second through holes 2121, or, the first inorganic barrier layer 112 is a whole-layer structure, the third inorganic barrier layer 212 is a structure with a plurality of second through holes 2121, or, the first inorganic barrier layer 112 has a structure with a plurality of second through holes 2121 The structure of the plurality of first through holes 1121 and the third inorganic barrier layer 212 is a whole-layer structure.

In this embodiment, the fourth organic buffer layer 213 can also be connected with the third organic buffer layer 211 , so that the fourth organic buffer layer 213 and the third organic buffer layer 211 are in an integrated structure, which can further alleviate the third inorganic barrier layer 212 and the bending stress of the fourth inorganic barrier layer 214 to prevent the second flexible substrate 21 from being broken during bending.

In this embodiment, the shape of the plurality of second through holes 2121 can be triangular, circular, rectangular or polygonal, so that the third inorganic barrier layer 212 is in a grid shape as a whole, or the shape of the plurality of second through holes 2121 It can be a long strip with both ends located at the edge of the third inorganic barrier layer 212 , so that the third inorganic barrier layer 212 is arranged in a plurality of strip structures as a whole.

In some embodiments, please refer to FIG. 3 and FIG. 4 , the OLED substrate 2 further includes a pixel definition layer 25 disposed under the first electrode 22 , and a protruding portion 26 disposed under the pixel definition layer 25 . The OLED functional layer 23 is located in the pixel definition layer 25 , the second electrode 24 is disposed under the pixel definition layer 25 , and the protruding portion 26 is located between the pixel definition layer 25 and the second electrode 24 . That is, in the present application, the second electrode 24 is raised by the raised portion 26 to ensure that the second electrode 24 can be connected to the TFT layer 12 , so as to ensure that the OLED functional layer 23 can emit light normally.

In addition, please refer to FIG. 3 and FIG. 4 , the TFT substrate 1 and the OLED substrate 2 may be connected by an adhesive layer 4 , wherein if the adhesive layer 4 is bonded to the second electrode 24 , the adhesive layer 4 may be a conductive adhesive, such as Gold glue or silver glue. If the adhesive layer 4 is bonded to the non-electrode structure, the adhesive layer 4 may be a non-conductive adhesive, such as epoxy resin adhesive.

In some embodiments, please refer to FIG. 3 and FIG. 4 , the TFT substrate 1 further includes a flat layer 13 disposed on the TFT layer 12 , and a bonding electrode 14 disposed on the flat layer 13 . The flat layer 13 has a via hole exposing the TFT layer 12 , the bonding electrode 14 is connected to the TFT layer 12 through the via hole, and the second electrode 24 is connected to the bonding electrode 14 . That is, a part of the overlap electrode 14 is located in the via hole and is connected to the TFT layer 12 , and the other part is located on the flat layer 13 . The overlap electrode 14 can not only facilitate the connection between the second electrode 24 and the TFT layer 12 , but also lower the level of the second electrode 24 and the resistance of the TFT layer 12 to improve the electrical performance of the flexible display panel.

In some embodiments, please refer to FIGS. 3 and 4 , the TFT layer 12 includes a light shielding layer 121 disposed on the first flexible substrate 11 , a first insulating layer disposed on the first flexible substrate 11 and the light shielding layer 121 122. The active layer 123 provided on the first insulating layer 122, the second insulating layer 124 provided on the active layer 123, the gate electrode 125 provided on the second insulating layer 124, and the first insulating layer 122 , the third insulating layer 126 on the active layer 123 and the gate electrode 125, the source electrode 127 and the drain electrode 128 on the third insulating layer 126, and the third insulating layer 126, the source electrode 127 and the drain electrode 128 on the third insulating layer 126 on the passivation layer 129.

The source electrode 127 and the drain electrode 128 are connected to the active layer 123 through the third insulating layer 126 , the passivation layer 129 also has a via hole exposing the drain electrode 128 , and the bonding electrode 14 is connected to the drain electrode 128 .

In addition, the TFT layer 12 may further include a connection electrode 1210 disposed in the same layer as the drain electrode 128 , the connection electrode 1210 is connected to the light shielding layer 121 through the third insulating layer 126 and the first insulating layer 122 , and the connection electrode 1210 can be used for the light shielding layer 121 A stable voltage is provided to avoid the floating gate effect of the light shielding layer 121, thereby effectively improving the working stability of the flexible display panel.

Referring to FIGS. 5 to 9 , based on the above-mentioned flexible display panel, an embodiment of the present application further provides a method for manufacturing a flexible display panel, including:

Step S1, providing a first carrier board 5, and fabricating a first flexible substrate 11 on the first carrier board 5;

Step S2, fabricating the TFT layer 12 on the first flexible substrate 11 to form the TFT substrate 1;

Step S3, providing the second carrier board 6, and fabricating the second flexible substrate 21 on the second carrier board 6;

Step S4, forming a first electrode 22 on the second flexible substrate 21, forming an OLED functional layer 23 on the first electrode 22, forming a second electrode 24 on the OLED functional layer 23, and peeling off the second carrier plate 6 to form an OLED substrate 2;

Step S5, aligning and bonding the TFT substrate 1 and the OLED substrate 2, and connecting the second electrode 24 to the TFT layer 12;

Step S6 , forming an encapsulation layer 3 on the TFT substrate 1 and the OLED substrate 2 . The encapsulation layer 3 surrounds the OLED substrate 2 and has an opening 301 exposing the second flexible substrate 21 in the encapsulation layer 3 .

Step S7 , peeling off the first carrier plate 5 .

It should be noted that the TFT layer 12 and the OLED functional layer 23 of the present application are not fabricated on the same substrate, but the TFT layer 12 and the OLED functional layer 23 are fabricated on the first flexible substrate 11 and the second flexible substrate 21 respectively. On the top, two substrates are formed, so that the upper and lower sides of the flexible display panel can block water and oxygen through the first flexible substrate 11 and the second flexible substrate 21, so that the encapsulation layer 3 only needs to surround the OLED substrate 2 and block the sides. Invading water and oxygen, and the encapsulation layer 3 only surrounds the OLED substrate 2 and does not need to cover the entire surface of the OLED substrate 2. Therefore, the encapsulation layer 3 may have an opening 301 exposing the second flexible substrate 21. During the folding process, the opening 301 can release the bending stress of the encapsulation layer 3 , thereby preventing the encapsulation layer 3 from breaking, so that the encapsulation layer 3 can effectively block water and oxygen.

In addition, compared with the prior art in which the TFT layer 12 and the OLED functional layer 23 are fabricated on the same substrate, the present application fabricates the TFT layer 12 and the OLED functional layer 23 on the first flexible substrate 11 and the second flexible substrate 21 respectively. On the above, two substrates are formed, which can also improve the process yield.

In some embodiments, referring to FIG. 6 , in step S1 , before fabricating the first flexible substrate 11 on the first carrier board 5 , the first sacrificial layer 7 may also be fabricated on the first carrier board 5 . In step S7, the first sacrificial layer 7 and the first carrier plate 5 are simultaneously peeled off by using a laser lift-off process. The material of the first sacrificial layer 7 can be amorphous silicon, and the thickness can be

Referring to FIG. 7 , in step S3 , before the second flexible substrate 21 is fabricated on the second carrier board 6 , the second sacrificial layer 8 may also be fabricated on the second carrier board 6 . In step S4, the second sacrificial layer 8 and the second carrier plate 6 are simultaneously peeled off by using a laser lift-off process. The material of the second sacrificial layer 8 can be amorphous silicon, and the thickness can be

In some embodiments, please refer to FIG. 6 , in step S1 , fabricating the first flexible substrate 11 on the first carrier board includes: fabricating the first organic buffer layer 111 on the first carrier board; A first inorganic barrier layer 112 is fabricated on 111 ; a second organic buffer layer 113 is fabricated on the first inorganic barrier layer 112 ; and a second inorganic barrier layer 114 is fabricated on the second organic buffer layer 113 . The first inorganic barrier layer 112 and the second inorganic barrier layer 114 can block water and oxygen intruding from the lower side of the flexible display panel, and the first organic buffer layer 111 and the second organic buffer layer 113 can relieve the first inorganic barrier layer 112 and the second organic buffer layer 112. The bending stress of the inorganic barrier layer 114 prevents the first flexible substrate 11 from being broken during bending.

In this embodiment, in step S1, in a high temperature environment, such as a temperature of 360-380°C, the first inorganic barrier layer 112 is fabricated by chemical vapor deposition. The chemical vapor deposition method is used to fabricate the second inorganic barrier layer 114 , so that the first inorganic barrier layer 112 and the second inorganic barrier layer 114 are high temperature dense film layers, which can further improve the ability of the first flexible substrate 11 to block water and oxygen.

In this embodiment, please refer to FIG. 8 , before forming the second organic buffer layer 113 on the first inorganic barrier layer 112 in step S1 , the first inorganic barrier layer 112 may also be patterned to make the first inorganic barrier layer 112 The layer 112 forms a plurality of first through holes 1121 exposing the first organic buffer layer 111 , and the second organic buffer layer 113 formed subsequently is also filled in the plurality of first through holes 1121 . The plurality of first through holes 1121 can further relieve the bending stress of the first inorganic barrier layer 112 when the first inorganic barrier layer 112 is bent, and prevent the first inorganic barrier layer 112 from breaking when the first inorganic barrier layer 112 is bent. In addition, the second organic buffer layer 113 is also filled in the plurality of first through holes 1121 , so that the second organic buffer layer 113 can further relieve the bending stress of the first inorganic barrier layer 112 .

In some embodiments, please refer to FIG. 7 , in step S3 , the second flexible substrate 21 is fabricated on the second carrier board, including: fabricating the third organic buffer layer 211 on the second carrier board; A third inorganic barrier layer 212 is formed on 211 ; a fourth organic buffer layer 213 is formed on the third inorganic barrier layer 212 ; and a fourth inorganic barrier layer 214 is formed on the fourth organic buffer layer 213 . The third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 can block water and oxygen intruding from the upper side of the flexible display panel, and the third organic buffer layer 211 and the fourth organic buffer layer 213 can relieve the third inorganic barrier layer 212 and the fourth The bending stress of the inorganic barrier layer 214 prevents the second flexible substrate 21 from being broken during bending.

In this embodiment, in step S3, in a high temperature environment, such as a temperature of 360-380°C, the third inorganic barrier layer 212 is fabricated by chemical vapor deposition. In a high temperature environment, such as a temperature of 420-440°C, The fourth inorganic barrier layer 214 is fabricated by chemical vapor deposition, and the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 are high temperature dense film layers, which can further improve the ability of the second flexible substrate 21 to block water and oxygen.

In this embodiment, please refer to FIG. 9 , before forming the fourth organic buffer layer 213 on the third inorganic barrier layer 212 in step S3 , the third inorganic barrier layer 212 may be patterned to make the third inorganic barrier layer 212 The layer 212 forms a plurality of second through holes 2121 exposing the third organic buffer layer 211 , and the fourth organic buffer layer 213 formed subsequently is also filled in the plurality of second through holes 2121 . The plurality of second through holes 2121 can further relieve the bending stress of the third inorganic barrier layer 212 when the third inorganic barrier layer 212 is bent, and prevent the third inorganic barrier layer 212 from breaking when the third inorganic barrier layer 212 is bent. In addition, the fourth organic buffer layer 213 is also filled in the plurality of second through holes 2121 , so that the fourth organic buffer layer 213 can further relieve the bending stress of the third inorganic barrier layer 212 .

In some embodiments, referring to FIG. 6 , in step S2, the TFT layer 12 is fabricated on the first flexible substrate 11, including:

The light shielding layer 121 is fabricated on the first flexible substrate 11 by physical vapor sputtering; the material of the light shielding layer 121 can be molybdenum titanium (MoTi), molybdenum (Mo), copper (Cu), silver (Ag), aluminum (Al) other metals and their alloys;

The first insulating layer 122 is formed on the first flexible substrate 11 and the light shielding layer 121 by chemical vapor deposition, and the first insulating layer 122 is annealed at high temperature;

A metal oxide is formed on the first insulating layer 122 by physical vapor sputtering, and a photolithography process or a wet etching process is performed on the metal oxide to form the active layer 123;

The insulating material is deposited on the first insulating layer 122 and the active layer 123 by chemical vapor deposition, the metal material is deposited on the insulating material by physical vapor deposition, and the insulating material and the metal material are etched by a photolithography process to form a second insulating layer 124 and gate 125;

Conduct conductive treatment on the active layer 123 by self-aligning the gate 125;

A third insulating layer 126 is formed on the first insulating layer 122, the active layer 123 and the gate electrode 125 by chemical vapor deposition;

The source electrode 127 and the drain electrode 128 are fabricated on the third insulating layer 126 by physical vapor sputtering, and the source electrode 127 and the drain electrode 128 are connected to the active layer 123 through the third insulating layer 126; The material can be molybdenum titanium, molybdenum, copper, silver, aluminum and other metals and their alloys;

A passivation layer 129 is formed on the third insulating layer 126 , the source electrode 127 and the drain electrode 128 by chemical vapor deposition.

In some embodiments, please refer to FIG. 6 , after the TFT layer 12 is formed on the first flexible substrate 11 in step S2 , a flat layer 13 may be formed on the TFT layer 12 , and the bonding electrode 14 may be formed on the flat layer 13 . The flat layer 13 has a via hole exposing the TFT layer 12 , the bonding electrode 14 is connected to the TFT layer 12 through the via hole, and the second electrode 24 is connected to the bonding electrode 14 . That is, a part of the overlap electrode 14 is located in the via hole and is connected to the TFT layer 12 , and the other part is located on the flat layer 13 . The overlap electrode 14 can not only facilitate the connection between the second electrode 24 and the TFT layer 12 , but also lower the level of the second electrode 24 and the resistance of the TFT layer 12 to improve the electrical performance of the flexible display panel.

In some embodiments, please refer to FIG. 7 , before the OLED functional layer 23 is formed on the first electrode 22 in step S4 , a pixel definition layer 25 may also be formed on the first electrode 22 , and the OLED functional layer 23 is formed on the pixel definition layer. In the layer 25, a raised portion 26 is formed on the pixel definition layer 25, and then a second electrode 24 is formed on the pixel definition layer 25, the raised portion 26 and the OLED functional layer 23, so that the raised portion 26 is located on the pixel definition layer 25. and the second electrode 24 . The raised portion 26 can raise the second electrode 24 to ensure that the second electrode 24 can be connected to the TFT layer 12 , so as to ensure that the OLED functional layer 23 can emit light normally.

In addition, in step S5, the TFT substrate 1 and the OLED substrate 2 may be connected by an adhesive layer 4, wherein if the adhesive layer 4 is bonded to the second electrode 24, the adhesive layer 4 may be a conductive adhesive, such as gold adhesive or silver adhesive. If the adhesive layer 4 is bonded to the non-electrode structure, the adhesive layer 4 may be a non-conductive adhesive, such as epoxy resin adhesive.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments. During specific implementation, the above units or structures can be implemented as independent entities, or can be arbitrarily combined to be implemented as the same or several entities. The specific implementation of the above units or structures can refer to the previous method embodiments. No longer.

A flexible display panel and a manufacturing method thereof provided by the embodiments of the present application have been described in detail above. The principles and implementations of the embodiments of the present application are described in this paper by using specific examples. The descriptions of the above embodiments are only for the purpose of Help to understand the technical solutions of the embodiments of the present application and their core ideas; those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements to some of the technical features; and These modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A flexible display panel, comprising: a TFT substrate, the TFT substrate includes a first flexible substrate, and a TFT layer disposed on the first flexible substrate; an OLED substrate, the OLED substrate is disposed above the TFT substrate, and the OLED substrate includes a second flexible substrate, a first electrode disposed under the second flexible substrate, and a first electrode disposed under the first electrode an OLED functional layer, and a second electrode disposed under the OLED functional layer; the second electrode is connected to the TFT layer; An encapsulation layer, the encapsulation layer is disposed on the TFT substrate and the OLED substrate, and surrounds the periphery of the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate. 2 . The flexible display panel according to claim 1 , wherein the first flexible substrate comprises a first organic buffer layer, a first inorganic barrier layer disposed on the first organic buffer layer, and a first inorganic barrier layer disposed on the first organic buffer layer. 3 . A second organic buffer layer on the first inorganic barrier layer, and a second inorganic barrier layer on the second organic buffer layer. 3 . The flexible display panel according to claim 2 , wherein the first inorganic barrier layer and the second inorganic barrier layer are high temperature dense film layers. 4 . 4 . The flexible display panel of claim 2 , wherein the first inorganic barrier layer has a plurality of first through holes exposing the first organic buffer layer, and the second organic buffer layer Also filled in the plurality of first through holes. 5 . The flexible display panel of claim 1 , wherein the second flexible substrate comprises a third organic buffer layer, a third inorganic barrier layer disposed under the third organic buffer layer, and a third inorganic barrier layer disposed under the third organic buffer layer. 6 . a fourth organic buffer layer under the third inorganic barrier layer, and a fourth inorganic barrier layer under the fourth organic buffer layer. 6 . The flexible display panel according to claim 5 , wherein the third inorganic barrier layer and the fourth inorganic barrier layer are high temperature dense film layers. 7 . 7 . The flexible display panel of claim 5 , wherein the third inorganic barrier layer has a plurality of second through holes exposing the third organic buffer layer, and the fourth organic buffer layer Also filled in the plurality of second through holes. 8 . The flexible display panel according to claim 1 , wherein the OLED substrate further comprises a pixel definition layer provided under the first electrode, and a pixel definition layer provided on the pixel definition layer. 9 . the lower protrusion; The OLED functional layer is located in the pixel definition layer, the second electrode is located under the pixel definition layer, and the protrusion is located between the pixel definition layer and the second electrode. 9. The flexible display panel according to any one of claims 1 to 7, wherein the TFT substrate further comprises a flat layer disposed on the TFT layer, and a lamination layer disposed on the flat layer connected to the electrode; The flat layer has a via hole exposing the TFT layer, the overlapping electrode is connected to the TFT layer through the via hole, and the second electrode is connected to the overlapping electrode. 10. A method for manufacturing a flexible display panel, comprising: providing a first carrier board, and fabricating a first flexible substrate on the first carrier board; fabricating a TFT layer on the first flexible substrate to form a TFT substrate; providing a second carrier board, and fabricating a second flexible substrate on the second carrier board; forming a first electrode on the second flexible substrate, forming an OLED functional layer on the first electrode, forming a second electrode on the OLED functional layer, and peeling off the second carrier plate to form an OLED substrate; aligning the TFT substrate with the OLED substrate, and connecting the second electrode with the TFT layer; An encapsulation layer is formed on the TFT substrate and the OLED substrate, the encapsulation layer surrounds the periphery of the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate; Peel off the first carrier plate.

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