Flexible display panel and manufacturing method thereof

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 is connected to the TFT layer. The encapsulation layer is disposed on the TFT substrate and the OLED substrate, and surrounds the four sides of 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 four sides of the OLED substrate to block the water and oxygen invading from the side, so the encapsulation layer can have an opening exposing the second flexible substrate, and the opening can release the bending stress of the encapsulation layer, thereby avoiding the encapsulation layer from breaking, so that the encapsulation layer can effectively block water and oxygen.

Description

Technical Field

[0001] 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 Art

[0002] OLEDs have the advantages of simple preparation process, low cost, high luminous efficiency, easy formation of flexible structure, low power consumption, high color saturation and wide viewing angle. Display technology using OLEDs has become an important display technology.

[0003] 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 drive of the electric field formed by the anode and the cathode.

[0004] The flexible display panel of 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 during use, or even bent frequently. However, as the number of bends increases, 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

[0005] The present application provides a flexible display panel and a manufacturing method thereof, so as to solve the problem in the prior art that the encapsulation layer cannot release stress during the bending process and is easily broken, resulting in the inability to effectively block water and oxygen.

[0006] In one aspect, the present application provides a flexible display panel, comprising:

[0007] A TFT substrate, the TFT substrate comprising a first flexible substrate and a TFT layer disposed on the first flexible substrate;

[0008] An OLED substrate, the OLED substrate is disposed above the TFT substrate, the OLED substrate comprises 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 is connected to the TFT layer;

[0009] The encapsulation layer is disposed on the TFT substrate and the OLED substrate and surrounds the OLED substrate. The encapsulation layer has an opening for exposing the second flexible substrate.

[0010] 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, a second organic buffer layer disposed on the first inorganic barrier layer, and a second inorganic barrier layer disposed on the second organic buffer layer.

[0011] In some possible implementations, the first inorganic barrier layer and the second inorganic barrier layer are high-temperature dense film layers.

[0012] 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 through holes.

[0013] 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, a fourth organic buffer layer disposed under the third inorganic barrier layer, and a fourth inorganic barrier layer disposed under the fourth organic buffer layer.

[0014] In some possible implementations, the third inorganic barrier layer and the fourth inorganic barrier layer are high-temperature dense film layers.

[0015] 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 also filled in the plurality of second through holes.

[0016] In some possible implementations, the OLED substrate further includes a pixel definition layer disposed under the first electrode, and a protrusion disposed under the pixel definition layer;

[0017] The OLED functional layer is located in the pixel definition layer, the second electrode is arranged under the pixel definition layer, and the protrusion is located between the pixel definition layer and the second electrode.

[0018] In some possible implementations, the TFT substrate further includes a planar layer disposed on the TFT layer, and a bonding electrode disposed on the planar layer;

[0019] The planar layer has a via hole exposing the TFT layer, the bonding electrode passes through the via hole and is connected to the TFT layer, and the second electrode is connected to the bonding electrode.

[0020] On the other hand, the present application also provides a method for manufacturing a flexible display panel, comprising:

[0021] Providing a first carrier plate, and manufacturing a first flexible substrate on the first carrier plate;

[0022] Fabricating a TFT layer on the first flexible substrate to form a TFT substrate;

[0023] Providing a second carrier plate, and manufacturing a second flexible substrate on the second carrier plate;

[0024] Fabricating a first electrode on the second flexible substrate, fabricating an OLED functional layer on the first electrode, fabricating a second electrode on the OLED functional layer, and peeling off the second carrier plate to form an OLED substrate;

[0025] Aligning and laminating the TFT substrate and the OLED substrate, and connecting the second electrode to the TFT layer;

[0026] Manufacturing an encapsulation layer on the TFT substrate and the OLED substrate, wherein the encapsulation layer surrounds the OLED substrate and has an opening in the encapsulation layer for exposing the second flexible substrate;

[0027] The first carrier sheet is peeled off.

[0028] 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 disposed above the TFT substrate, and 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 is connected to the TFT layer. The encapsulation layer is disposed on the TFT substrate and the OLED substrate, and surrounds the four sides of the OLED substrate, and the encapsulation layer has an opening exposing the second flexible substrate. That is, the present application arranges the TFT layer and the OLED functional layer on the first flexible substrate and the second flexible substrate respectively, 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 four sides of the OLED substrate to block the water and oxygen invading from the side, and the encapsulation layer only surrounds the four sides of the OLED substrate, and does not need to cover the entire surface of the OLED substrate, so the encapsulation layer can have an opening exposing the second flexible substrate, and during the bending process of the flexible display panel, the opening can release the bending stress of the encapsulation layer, thereby avoiding the breakage of the encapsulation layer, so that the encapsulation layer can effectively block water and oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 is a schematic diagram of a flexible display panel provided by an embodiment of the present application;

[0031] Figure 2 is a top view of a flexible display panel provided in one embodiment of the present application;

[0032] Figure 3 is a cross-sectional view of a flexible display panel provided in one embodiment of the present application;

[0033] Figure 4 is a cross-sectional view of a flexible display panel provided by another embodiment of the present application;

[0034] Figure 5 is a flow chart of a method for manufacturing a flexible display panel provided in one embodiment of the present application;

[0035] Figure 6 is a schematic diagram of steps S1-S2 of a method for manufacturing a flexible display panel provided in an embodiment of the present application;

[0036] Figure 7 is a schematic diagram of steps S3-S4 of a method for manufacturing a flexible display panel provided in an embodiment of the present application;

[0037] Figure 8 is a schematic diagram of step S1 of a method for manufacturing a flexible display panel provided in another embodiment of the present application;

[0038] Fig. 9 is a schematic diagram of step S3 of a method for manufacturing a flexible display panel provided in another embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than 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 are within the scope of protection of the present application.

[0040] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0043] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments discussed-and / or settings. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0044] See also Figures 1 to 4 , an embodiment of the present application provides a flexible display panel, comprising:

[0045] A TFT substrate 1, wherein the TFT substrate 1 comprises a first flexible substrate 11 and a TFT layer 12 disposed on the first flexible substrate 11;

[0046] The OLED substrate 2 is disposed above the TFT substrate 1, and includes a second flexible substrate 21, a first electrode 22 disposed under the second flexible substrate 21, an OLED functional layer 23 disposed under the first electrode 22, and a second electrode 24 disposed under the OLED functional layer 23; the second electrode 24 is connected to the TFT layer 12;

[0047] 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 .

[0048] It should be noted that the TFT layer 12 and the OLED functional layer 23 of the present application are not formed on the same substrate, but the TFT layer 12 and the OLED functional layer 23 are respectively arranged on the first flexible substrate 11 and the second flexible substrate 21 to form two substrates, 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 four sides of the OLED substrate 2 to block the water and oxygen invading from the side, and the encapsulation layer 3 only surrounds the four sides of the OLED substrate 2, and does not need to cover the entire surface of the OLED substrate 2, so the encapsulation layer 3 can have an opening 301 exposing the second flexible substrate 21, and during the bending process of the flexible display panel, the opening 301 can release the bending stress of the encapsulation layer 3, thereby avoiding the breakage of the encapsulation layer 3, so that the encapsulation layer 3 can effectively block water and oxygen.

[0049] 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 arranges the TFT layer 12 and the OLED functional layer 23 on the first flexible substrate 11 and the second flexible substrate 21 respectively to form two substrates, which can also improve the process yield.

[0050] The embodiments of the present application do not impose any specific restrictions on the applicability of the flexible display panel, which can be any product or component with a display function, such as a television, a laptop computer, a tablet computer, a wearable display device (such as a smart bracelet, a smart watch, etc.), a mobile phone, a virtual reality device, an augmented reality device, a car display, an advertising light box, etc.

[0051] In some embodiments, see Figure 2 The encapsulation layer 3 only needs to surround the OLED substrate 2 on all sides. Therefore, from a top view, the area of ​​the opening 301 of the flexible display panel can be slightly smaller than the area of ​​the second flexible substrate 21, so that the area of ​​the opening 301 of the flexible display panel is maximized, further reducing the stress of the encapsulation layer 3 when it is bent.

[0052] In some embodiments, see Figure 1 The encapsulation layer 3 may include two barrier layers 31 and a buffer layer 32 between the two barrier layers 31. The barrier layer 31 is an inorganic material, and the buffer layer 32 is an organic material. The two barrier layers 31 block water and oxygen, and the buffer layer 32 relieves the bending stress of the two barrier layers 31, further preventing the encapsulation layer 3 from breaking when bent.

[0053] In some embodiments, see Figure 3 and Figure 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 , and the second electrode 24 may be the anode, and the first electrode 22 may be the cathode.

[0054] 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 sequentially stacked along the direction in which the second electrode 24 approaches the first electrode 22 .

[0055] In some embodiments, see Figure 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, a second organic buffer layer 113 disposed on the first inorganic barrier layer 112, and a 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 bending stress of the first inorganic barrier layer 112 and the second inorganic barrier layer 114 to prevent the first flexible substrate 11 from breaking when being bent.

[0056] In this embodiment, the material of the first inorganic barrier layer 112 and the second inorganic barrier layer 114 can be a combination of one or more of silicon nitride, silicon oxide or silicon oxynitride. The material of the first organic buffer layer 111 and the second organic buffer layer 113 can be polyimide (PI), polyethylene terephthalate (PET) or polydimethylsiloxane (PDMS).

[0057] 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 layer formed by high-temperature production. The dense film has excellent water and oxygen blocking capabilities, and can further improve the ability of the first flexible substrate 11 to block water and oxygen. In addition, since the present application uses the first flexible substrate 11 and the second flexible substrate 21 to block 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 produced before the OLED functional layer 23 and the TFT layer 12 are produced. Therefore, the present application can use high temperature to produce the first inorganic barrier layer 112 and the second inorganic barrier layer 114. For example, the first inorganic barrier layer 112 can be produced at a temperature of 360-380°C, and the second inorganic barrier layer 114 can be produced at a temperature of 420-440°C. The prior art mainly relies on the encapsulation layer 3 to block the water and oxygen intruding into the flexible display panel. The encapsulation layer 3 of the prior art is made on the OLED substrate 2. Therefore, in order to avoid failure of the OLED functional layer 23 due to high temperature, the encapsulation layer 3 of the prior art is made of a low-temperature film, for example, made at a temperature of 80-85°C, resulting in a loose film quality and limited ability to block water and oxygen. Therefore, the first flexible substrate 11 of the present application has a better ability to block water and oxygen than the encapsulation layer 3 of the prior art.

[0058] In some embodiments, see Figure 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. When the first inorganic barrier layer 112 is bent, the plurality of first through holes 1121 can further relieve the bending stress of the first inorganic barrier layer 112, thereby preventing the first inorganic barrier layer 112 from breaking when bent. 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 also further relieve the bending stress of the first inorganic barrier layer 112.

[0059] 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 an integrated structure, which can further alleviate the bending stress of the first inorganic barrier layer 112 and the second inorganic barrier layer 114 and prevent the first flexible substrate 11 from breaking when bent.

[0060] In this embodiment, the shapes of the multiple first through holes 1121 can be triangular, circular, rectangular or polygonal, so that the first inorganic barrier layer 112 is grid-shaped as a whole. Alternatively, the shapes of the multiple first through holes 1121 can be long strips 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.

[0061] In some embodiments, see Figure 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, a fourth organic buffer layer 213 disposed under the third inorganic barrier layer 212, and a 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 bending stress of the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 to prevent the second flexible substrate 21 from breaking when being bent.

[0062] In this embodiment, the material of the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 may be a combination of one or more of silicon nitride, silicon oxide or silicon oxynitride. The material of the third organic buffer layer 211 and the fourth organic buffer layer 213 may be polyimide (PI), polyethylene terephthalate (PET) or polydimethylsiloxane (PDMS).

[0063] 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 layer formed by high-temperature production. The dense film has excellent water and oxygen blocking capabilities, and can further improve the ability of the second flexible substrate 21 to block water and oxygen. In addition, since the present application uses the first flexible substrate 11 and the second flexible substrate 21 to block water and oxygen invading the upper and lower sides of the flexible display panel, and the first flexible substrate 11 and the second flexible substrate 21 are produced before the OLED functional layer 23 and the TFT layer 12 are produced, the present application can use high temperature to produce the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214. For example, the third inorganic barrier layer 212 can be produced at a temperature of 360-380°C, and the fourth inorganic barrier layer 214 can be produced at a temperature of 420-440°C. The prior art mainly relies on the encapsulation layer 3 to block the water and oxygen intruding from the flexible display panel. The encapsulation layer 3 of the prior art is made on the OLED substrate 2. Therefore, in order to avoid failure of the OLED functional layer 23 due to high temperature, the encapsulation layer 3 of the prior art is made of a low-temperature film, for example, made at a temperature of 80-85°C, resulting in a loose film quality and limited ability to block water and oxygen. Therefore, the second flexible substrate 21 of the present application has a better ability to block water and oxygen than the encapsulation layer 3 of the prior art.

[0064] In some embodiments, see Figure 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. When the third inorganic barrier layer 212 is bent, the plurality of second through holes 2121 can further relieve the bending stress of the third inorganic barrier layer 212 to prevent the third inorganic barrier layer 212 from breaking when bent. 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 also further relieve the bending stress of the third inorganic barrier layer 212.

[0065] In addition, the first inorganic barrier layer 112 may be a whole layer structure or a structure having a plurality of first through holes 1121, and the third inorganic barrier layer 212 may be a whole layer structure or a structure having a plurality of second through holes 2121, so the structure of the first inorganic barrier layer 112 and the third inorganic barrier layer 212 may be selected according to the situation, and the present application does not limit it here. For example, the first inorganic barrier layer 112 and the third inorganic barrier layer 212 are both whole layer structures, or the first inorganic barrier layer 112 is a structure having a plurality of first through holes 1121, and the third inorganic barrier layer 212 is a structure having a plurality of second through holes 2121, or the first inorganic barrier layer 112 is a whole layer structure, and the third inorganic barrier layer 212 is a structure having a plurality of second through holes 2121, or the first inorganic barrier layer 112 is a structure having a plurality of first through holes 1121, and the third inorganic barrier layer 212 is a whole layer structure.

[0066] In this embodiment, the fourth organic buffer layer 213 can also be connected to the third organic buffer layer 211, so that the fourth organic buffer layer 213 and the third organic buffer layer 211 are an integrated structure, which can further alleviate the bending stress of the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 and prevent the second flexible substrate 21 from breaking when bent.

[0067] In this embodiment, the shapes of the multiple second through holes 2121 can be triangles, circles, rectangles or polygons, so that the third inorganic barrier layer 212 is grid-shaped as a whole. Alternatively, the shapes of the multiple second through holes 2121 can be long strips 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.

[0068] In some embodiments, see Figure 3 and Figure 4 , the OLED substrate 2 further includes a pixel definition layer 25 disposed under the first electrode 22, and a protrusion 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 protrusion 26 is located between the pixel definition layer 25 and the second electrode 24. That is, the present application elevates the second electrode 24 through the protrusion 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.

[0069] Also, see Figure 3 and Figure 4 The TFT substrate 1 and the OLED substrate 2 may be connected via 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.

[0070] In some embodiments, see Figure 3 and Figure 4 The TFT substrate 1 further includes a planar layer 13 disposed on the TFT layer 12, and a strapping electrode 14 disposed on the planar layer 13. The planar layer 13 has a via hole exposing the TFT layer 12, the strapping electrode 14 passes through the via hole and is connected to the TFT layer 12, and the second electrode 24 is connected to the strapping electrode 14. That is, a part of the strapping electrode 14 is located in the via hole and is connected to the TFT layer 12, and the other part is located on the planar layer 13. The strapping electrode 14 can not only facilitate the connection between the second electrode 24 and the TFT layer 12, but also reduce the resistance between the second electrode 24 and the TFT layer 12, thereby improving the electrical performance of the flexible display panel.

[0071] In some embodiments, see Figure 3 and Figure 4 The TFT layer 12 includes a light shielding layer 121 disposed on the first flexible substrate 11, a first insulating layer 122 disposed on the first flexible substrate 11 and the light shielding layer 121, an active layer 123 disposed on the first insulating layer 122, a second insulating layer 124 disposed on the active layer 123, a gate electrode 125 disposed on the second insulating layer 124, a third insulating layer 126 disposed on the first insulating layer 122, the active layer 123 and the gate electrode 125, a source electrode 127 and a drain electrode 128 disposed on the third insulating layer 126, and a passivation layer 129 disposed on the third insulating layer 126, the source electrode 127 and the drain electrode 128.

[0072] The source electrode 127 and the drain electrode 128 pass through the third insulating layer 126 and are connected to the active layer 123 . The passivation layer 129 also has a via hole exposing the drain electrode 128 . The lap electrode 14 is connected to the drain electrode 128 .

[0073] In addition, the TFT layer 12 may also include a connecting electrode 1210 arranged in the same layer as the drain electrode 128. The connecting electrode 1210 passes through the third insulating layer 126 and the first insulating layer 122 to be connected to the light-shielding layer 121. The connecting electrode 1210 can provide a stable voltage to the light-shielding layer 121 to prevent the light-shielding layer 121 from generating a floating gate effect, thereby effectively improving the working stability of the flexible display panel.

[0074] See also Figures 5 to 9 Based on the above-mentioned flexible display panel, the embodiment of the present application further provides a method for manufacturing a flexible display panel, including:

[0075] Step S1, providing a first carrier plate 5, and manufacturing a first flexible substrate 11 on the first carrier plate 5;

[0076] Step S2, manufacturing a TFT layer 12 on the first flexible substrate 11 to form a TFT substrate 1;

[0077] Step S3, providing a second carrier plate 6, and manufacturing a second flexible substrate 21 on the second carrier plate 6;

[0078] 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;

[0079] Step S5, aligning and laminating the TFT substrate 1 and the OLED substrate 2, and connecting the second electrode 24 to the TFT layer 12;

[0080] Step S6 , manufacturing a packaging layer 3 on the TFT substrate 1 and the OLED substrate 2 , wherein the packaging layer 3 surrounds the OLED substrate 2 , and has an opening 301 in the packaging layer 3 for exposing the second flexible substrate 21 .

[0081] Step S7, peeling off the first carrying plate 5.

[0082] It should be noted that the TFT layer 12 and the OLED functional layer 23 of the present application are not made on the same substrate, but the TFT layer 12 and the OLED functional layer 23 are respectively made on the first flexible substrate 11 and the second flexible substrate 21 to form two substrates, 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 four sides of the OLED substrate 2 to block the water and oxygen invading from the side, and the encapsulation layer 3 only surrounds the four sides of the OLED substrate 2, and does not need to cover the entire surface of the OLED substrate 2, so the encapsulation layer 3 can have an opening 301 exposing the second flexible substrate 21, and during the bending process of the flexible display panel, the opening 301 can release the bending stress of the encapsulation layer 3, thereby avoiding the breakage of the encapsulation layer 3, so that the encapsulation layer 3 can effectively block water and oxygen.

[0083] In addition, compared with the prior art in which the TFT layer 12 and the OLED functional layer 23 are made on the same substrate, the present application respectively makes the TFT layer 12 and the OLED functional layer 23 on the first flexible substrate 11 and the second flexible substrate 21 to form two substrates, which can also improve the process yield.

[0084] In some embodiments, see Figure 6 In step S1, before manufacturing the first flexible substrate 11 on the first carrier plate 5, a first sacrificial layer 7 may be manufactured on the first carrier plate 5. In step S7, the first sacrificial layer 7 and the first carrier plate 5 are simultaneously peeled off by a laser lift-off process. The material of the first sacrificial layer 7 may be amorphous silicon and the thickness may be

[0085] See also Figure 7In step S3, before manufacturing the second flexible substrate 21 on the second carrier plate 6, a second sacrificial layer 8 may be manufactured on the second carrier plate 6. In step S4, the second sacrificial layer 8 and the second carrier plate 6 are simultaneously peeled off by a laser lift-off process. The material of the second sacrificial layer 8 may be amorphous silicon and the thickness may be

[0086] In some embodiments, see Figure 6 In step S1, a first flexible substrate 11 is fabricated on a first carrier plate, including: fabricating a first organic buffer layer 111 on the first carrier plate; fabricating a first inorganic barrier layer 112 on the first organic buffer layer 111; fabricating a second organic buffer layer 113 on the first inorganic barrier layer 112; and fabricating a second inorganic barrier layer 114 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 bending stress of the first inorganic barrier layer 112 and the second inorganic barrier layer 114 to prevent the first flexible substrate 11 from breaking when being bent.

[0087] In this embodiment, in step S1, the first inorganic barrier layer 112 is formed by chemical vapor deposition in a high temperature environment, such as at a temperature of 360-380°C, and the second inorganic barrier layer 114 is formed by chemical vapor deposition in a high temperature environment, such as at a temperature of 420-440°C, 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.

[0088] In this example, see Figure 8 In step S1, before forming the second organic buffer layer 113 on the first inorganic barrier layer 112, the first inorganic barrier layer 112 may be patterned so that the first inorganic barrier 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. When the first inorganic barrier layer 112 is bent, the plurality of first through holes 1121 may further relieve the bending stress of the first inorganic barrier layer 112, thereby preventing the first inorganic barrier layer 112 from breaking when 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 may also further relieve the bending stress of the first inorganic barrier layer 112.

[0089] In some embodiments, see Figure 7In step S3, a second flexible substrate 21 is fabricated on a second carrier plate, including: fabricating a third organic buffer layer 211 on the second carrier plate; fabricating a third inorganic barrier layer 212 on the third organic buffer layer 211; fabricating a fourth organic buffer layer 213 on the third inorganic barrier layer 212; and fabricating a fourth inorganic barrier layer 214 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 bending stress of the third inorganic barrier layer 212 and the fourth inorganic barrier layer 214 to prevent the second flexible substrate 21 from breaking when being bent.

[0090] In this embodiment, in step S3, the third inorganic barrier layer 212 is formed by chemical vapor deposition in a high temperature environment, such as at a temperature of 360-380°C, and the fourth inorganic barrier layer 214 is formed by chemical vapor deposition in a high temperature environment, such as at a temperature of 420-440°C, so that 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.

[0091] In this example, see Fig. 9 In step S3, before forming the fourth organic buffer layer 213 on the third inorganic barrier layer 212, the third inorganic barrier layer 212 may be patterned so that the third inorganic barrier 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. When the third inorganic barrier layer 212 is bent, the plurality of second through holes 2121 may further relieve the bending stress of the third inorganic barrier layer 212, thereby preventing the third inorganic barrier layer 212 from breaking when 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 may also further relieve the bending stress of the third inorganic barrier layer 212.

[0092] In some embodiments, see Figure 6 In step S2, a TFT layer 12 is formed on the first flexible substrate 11, comprising:

[0093] The light shielding layer 121 is manufactured 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) and other metals and their alloys;

[0094] 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 subjected to high temperature annealing;

[0095] 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 an active layer 123;

[0096] Depositing insulating material on the first insulating layer 122 and the active layer 123 by chemical vapor deposition, depositing metal material on the insulating material by physical vapor deposition, and etching the insulating material and the metal material by photolithography to form a second insulating layer 124 and a gate 125;

[0097] Conducting the active layer 123 by self-aligning the gate 125;

[0098] A third insulating layer 126 is formed on the first insulating layer 122, the active layer 123 and the gate 125 by chemical vapor deposition;

[0099] The source electrode 127 and the drain electrode 128 are formed on the third insulating layer 126 by physical vapor sputtering. The source electrode 127 and the drain electrode 128 pass through the third insulating layer 126 and are connected to the active layer 123. The material of the source electrode 127 and the drain electrode 128 can be molybdenum titanium, molybdenum, copper, silver, aluminum and other metals and alloys thereof.

[0100] 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.

[0101] In some embodiments, see Figure 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 a strapping electrode 14 may be formed on the flat layer 13. The flat layer 13 has a via hole exposing the TFT layer 12, the strapping electrode 14 passes through the via hole and is connected to the TFT layer 12, and the second electrode 24 is connected to the strapping electrode 14. That is, a part of the strapping 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 strapping electrode 14 can not only facilitate the connection between the second electrode 24 and the TFT layer 12, but also reduce the resistance between the second electrode 24 and the TFT layer 12, thereby improving the electrical performance of the flexible display panel.

[0102] In some embodiments, see Figure 7In step S4, before forming the OLED functional layer 23 on the first electrode 22, a pixel definition layer 25 may be formed on the first electrode 22, the OLED functional layer 23 is formed in the pixel definition layer 25, and then a protrusion 26 is formed on the pixel definition layer 25, and then a second electrode 24 is formed on the pixel definition layer 25, the protrusion 26 and the OLED functional layer 23, so that the protrusion 26 is located between the pixel definition layer 25 and the second electrode 24. The protrusion 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.

[0103] In addition, in step S5, the TFT substrate 1 and the OLED substrate 2 may be connected by the 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.

[0104] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. In specific implementation, the above units or structures can be implemented as independent entities, or can be arbitrarily combined and implemented as the same or several entities. The specific implementation of the above units or structures can refer to the previous method embodiments, which will not be repeated here.

[0105] The above is a detailed introduction to a flexible display panel and a manufacturing method thereof provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the embodiments of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the embodiments of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A flexible display panel, characterized in that: include: A TFT substrate, the TFT substrate comprising 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, the OLED substrate comprises 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 is connected to the TFT layer; An encapsulation layer, wherein the encapsulation layer is disposed 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; The area of ​​the opening is smaller than the area of ​​the second flexible substrate, the number of the opening is 1, and the packaging layer includes two barrier layers and a buffer layer located between the two barrier layers.

2. The flexible display panel according to claim 1, characterized in that: The first flexible substrate includes a first organic buffer layer, a first inorganic barrier layer disposed on the first organic buffer layer, a second organic buffer layer disposed on the first inorganic barrier layer, and a second inorganic barrier layer disposed on the second organic buffer layer.

3. The flexible display panel according to claim 2, characterized in that: The first inorganic barrier layer is a dense film layer formed at a temperature of 360-380°C; the second inorganic barrier layer is a dense film layer formed at a temperature of 420-440°C.

4. The flexible display panel according to claim 2, characterized in that: 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 through holes.

5. The flexible display panel according to claim 1, characterized in that: The second flexible substrate includes a third organic buffer layer, a third inorganic barrier layer disposed under the third organic buffer layer, a fourth organic buffer layer disposed under the third inorganic barrier layer, and a fourth inorganic barrier layer disposed under the fourth organic buffer layer.

6. The flexible display panel according to claim 5, characterized in that: The third inorganic barrier layer is a dense film layer formed at a temperature of 360-380°C; the fourth inorganic barrier layer is a dense film layer formed at a temperature of 420-440°C.

7. The flexible display panel according to claim 5, characterized in that: 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 also filled in the plurality of second through holes.

8. The flexible display panel according to any one of claims 1 to 7, characterized in that: The OLED substrate further includes a pixel definition layer disposed under the first electrode, and a protrusion disposed under the pixel definition layer; The OLED functional layer is located in the pixel definition layer, the second electrode is arranged 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, characterized in that: The TFT substrate further includes a planar layer disposed on the TFT layer, and a bonding electrode disposed on the planar layer; The planar layer has a via hole exposing the TFT layer, the bonding electrode passes through the via hole and is connected to the TFT layer, and the second electrode is connected to the bonding electrode.

10. A method for manufacturing a flexible display panel, characterized in that: include: Providing a first carrier plate, and manufacturing a first flexible substrate on the first carrier plate; Fabricating a TFT layer on the first flexible substrate to form a TFT substrate; Providing a second carrier plate, and manufacturing a second flexible substrate on the second carrier plate; Fabricating a first electrode on the second flexible substrate, fabricating an OLED functional layer on the first electrode, fabricating a second electrode on the OLED functional layer, and peeling off the second carrier plate to form an OLED substrate; Aligning and laminating the TFT substrate and the OLED substrate, and connecting the second electrode to the TFT layer; A packaging layer is fabricated on the TFT substrate and the OLED substrate, wherein the packaging layer surrounds the OLED substrate on all sides and has an opening in the packaging layer for exposing the second flexible substrate; the area of ​​the opening is smaller than the area of ​​the second flexible substrate, the number of the opening is 1, and the packaging layer includes two barrier layers and a buffer layer located between the two barrier layers; The first carrier sheet is peeled off.

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