Stretchable display panel, preparation method thereof, and stretchable display device

Abstract

The application provides a stretchable display panel, a preparation method thereof and a stretchable display device. The stretchable display panel comprises a stretchable substrate, a stretchable conductor wire arranged on the stretchable substrate, a pixel island comprising a base material and a light emitting unit arranged on the base material, the base material being arranged on the stretchable substrate, and the base material having a conductive hole, and a conductive column arranged in the conductive hole and electrically connected to the stretchable conductor wire and the light emitting unit respectively. The stretchable display panel can realize high stretchability and high PPI simultaneously.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a stretchable display panel, its manufacturing method, and a stretchable display device. Background Technology

[0002] In recent years, with the continuous development of flexible display technology, stretchable display panels have been gradually applied in wearable devices, IoT devices and artificial intelligence, bringing users a brand-new viewing and usage experience.

[0003] In related technologies, stretchable display panels are typically designed as island-bridge structures, meaning the stretchable display panel includes pixel islands and stretching bridges. The pixel islands support the display functional devices, while the stretching bridges support the stretching process and provide electrical signals to the display functional devices.

[0004] However, for stretchable display panels with island-bridge structures, achieving a high pixel density (PPI), i.e., increasing the area ratio of the island region to the total display panel area, inevitably requires reducing the area ratio of the stretch bridge to the total display panel area, thus leading to a decrease in the stretch ratio. Therefore, special design is needed to ensure a balance between high PPI and high stretch ratio. Summary of the Invention

[0005] This application provides a stretchable display panel and its manufacturing method, as well as a stretchable display device, aiming to solve the problem of how to ensure a balance between high PPI and large elongation of the stretchable display panel with an island bridge structure.

[0006] To solve the above-mentioned technical problems, one technical solution adopted in this application is to provide a stretchable display panel. The stretchable display panel includes: a stretchable substrate; stretchable conductive lines disposed on the stretchable substrate; pixel islands, including a substrate and light-emitting units disposed on the substrate; the substrate is disposed on the stretchable substrate; and the substrate has conductive holes; conductive pillars are inserted into the conductive holes and electrically connected to the stretchable conductive lines and the light-emitting units respectively.

[0007] In one embodiment of this application, it further includes: an adhesive layer disposed on the stretchable substrate; the stretchable wire and the pixel island are adhered to the adhesive layer on the side surface opposite to the stretchable substrate;

[0008] Preferably, the adhesive layer is provided with a plurality of hole structures; the orthographic projection of the pixel island on the stretchable substrate covers at least a portion of the orthographic projection of the plurality of hole structures on the stretchable substrate;

[0009] Preferably, the cross-section of the hole structure along the direction perpendicular to the stacking direction of the stretchable display panel is strip-shaped, circular, elliptical, polygonal, or irregular.

[0010] In one embodiment of this application, the stretchable wire is bent;

[0011] Preferably, the conductive post is disposed on the surface of the stretchable wire away from the stretchable substrate;

[0012] Preferably, the extension direction of the conductive pillar is perpendicular to the stretchable substrate;

[0013] Preferably, the conductive post is cylindrical, conical, or wedge-shaped;

[0014] Preferably, there are multiple conductive pillars, which are arranged in an array.

[0015] In one embodiment of this application, there are multiple pixel islands and multiple stretchable wires; the stretchable substrate includes multiple carrier regions and multiple bridging regions, the multiple carrier regions are spaced apart and adjacent two carrier regions are connected through the bridging regions; multiple stretchable wires are respectively disposed in the multiple bridging regions, and multiple pixel islands are respectively disposed in the multiple carrier regions; adjacent two pixel islands are connected through the stretchable wires; the stretchable wires located in different bridging regions are insulated;

[0016] Preferably, the stretchable conductors located in different bridging zones are spaced apart.

[0017] To solve the above-mentioned technical problems, another technical solution adopted in this application is: providing a method for manufacturing a stretchable display panel, the method comprising: providing a stretchable substrate and pixel islands; the pixel islands comprising a substrate and a light-emitting unit stacked thereon; and the substrate having conductive holes; forming curved stretchable wires on the stretchable substrate; forming conductive pillars on the stretchable substrate or in the conductive holes, and disposing the pixel islands on the stretchable substrate, and electrically connecting the stretchable wires and the light-emitting unit respectively.

[0018] In one embodiment of this application, the step of forming a bent stretchable wire on the stretchable substrate includes:

[0019] A tensile force is applied to the stretchable substrate;

[0020] Stretchable wires are formed on the stretchable substrate;

[0021] Release the tensile force on the stretchable substrate to cause the stretchable wire to bend.

[0022] In one embodiment of this application, the step of forming conductive pillars on the stretchable substrate or within the conductive hole, and disposing the pixel island on the stretchable substrate so that the conductive pillars are electrically connected to the stretchable wires and the light-emitting unit respectively, includes:

[0023] Conductive pillars are formed on the stretchable substrate and / or the stretchable wire; the conductive pillars are in contact with and electrically connected to the stretchable wire.

[0024] Align the conductive holes of the pixel island with the conductive pillars, and place the pixel island on the stretchable substrate so that the conductive pillars are electrically connected to the light-emitting unit;

[0025] Preferably, the extension direction of the conductive pillar is perpendicular to the stretchable substrate;

[0026] Preferably, the conductive hole is a blind hole structure formed on the substrate.

[0027] In one embodiment of this application, prior to the step of forming a bent stretchable wire on the stretchable substrate, the method further includes:

[0028] An adhesive layer is disposed on the stretchable substrate; the stretchable wire and the pixel island are disposed on the side surface of the adhesive layer opposite to the stretchable substrate.

[0029] In one embodiment of this application, after the step of forming the adhesive layer, the method further includes:

[0030] The adhesive layer is patterned to form a plurality of hole structures on the adhesive layer; wherein, when the pixel island is disposed on the stretchable substrate, the orthographic projection of the pixel island on the stretchable substrate covers at least a portion of the orthographic projection of the plurality of hole structures on the stretchable substrate;

[0031] Preferably, the cross-section of the hole structure along the direction perpendicular to the stacking direction of the stretchable display panel is strip-shaped, circular, elliptical, polygonal, or irregular.

[0032] Preferably, the orthographic projection of the pixel island on the stretchable substrate covers the entire orthographic projection of the plurality of hole structures on the stretchable substrate;

[0033] Preferably, the stretchable substrate includes multiple carrier regions and multiple bridging regions, the multiple carrier regions are spaced apart and adjacent carrier regions are connected through the bridging regions; the pixel island is located in the carrier region; a portion of the stretchable wire is located in the bridging region and a portion of the stretchable wire is located in the carrier region.

[0034] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a stretchable display device, which includes a stretchable display panel; the stretchable display panel is the stretchable display panel mentioned above; or the stretchable display panel is prepared by the stretchable display panel preparation method mentioned above.

[0035] The beneficial effects of this application's embodiments are as follows: Unlike existing technologies, this stretchable display panel includes a stretchable substrate, stretchable conductive lines, pixel islands, and conductive pillars. The stretchable conductive lines are disposed on the stretchable substrate and are curved. Each pixel island includes a substrate and light-emitting units disposed on the substrate. The substrate is disposed on the stretchable substrate and has conductive holes. The conductive pillars are inserted into the conductive holes and electrically connect the stretchable conductive lines and the light-emitting units, respectively. This stretchable display panel, by placing the stretchable conductive lines and the light-emitting units on two different planes and electrically connecting them via conductive pillars, allows the stretchable conductive lines to not occupy the distribution space of the light-emitting units, enabling a denser distribution of the light-emitting units and thus improving the display PPI. Furthermore, the light-emitting units also do not occupy the distribution space of the stretchable conductive lines, allowing for a denser distribution of the stretchable conductive lines and thus improving the stretchability of the stretchable conductive lines. Attached Figure Description

[0036] Figure 1 A simplified structural diagram of a stretchable display panel provided in one embodiment of this application;

[0037] Figure 2 for Figure 1 A schematic diagram of the specific structure at point A of the stretchable display panel shown.

[0038] Figure 3 for Figure 1 Another specific structural diagram of point A of the stretchable display panel shown.

[0039] Figure 4 This is a schematic diagram of the structure of a stretchable display panel provided in another embodiment of this application;

[0040] Figure 5 A flowchart illustrating a method for fabricating a stretchable display panel according to an embodiment of this application;

[0041] Figure 6 A schematic diagram of a structure in which an adhesive layer is disposed on a stretchable substrate, according to an embodiment of this application;

[0042] Figure 7 To Figure 6 The diagram shows the product structure after the structure has been graphically processed.

[0043] Figure 8A simplified planar schematic diagram of forming stretchable wires on a stretchable substrate according to an embodiment of this application;

[0044] Figure 9 for Figure 8 The diagram shows the product structure after the stretchable substrate has released its tensile force.

[0045] Figure 10 for Figure 9 Vertical cross-sectional view of the structure shown;

[0046] Figure 11 This is a schematic diagram of a structure for forming conductive pillars on a stretchable substrate according to an embodiment of this application;

[0047] Figure 12 A simplified three-dimensional structure diagram of the product after processing in step S32a, provided in an embodiment of this application;

[0048] Figure 13 A simplified structural diagram of a stretchable display device provided in an embodiment of this application.

[0049] Explanation of reference numerals in the attached figures

[0050] 10-Stretchable display panel; 1-Stretchable substrate; 11-Carrier area; 12-Bridging area; 2-Stretchable wire; 3-Pixel island; 31-Substrate; 310-Conductive hole; 311-Substrate island; 312-Active layer; 313-Gate insulating layer; 314-First metal layer; 315-Interlayer insulating layer; 316-Second metal layer; 317-Interlayer dielectric layer; 318-Third metal layer; 319-Planarization layer; 32-Light-emitting unit; 321-Anode; 322-Light-emitting functional layer; 333-Cathode; 33-Pixel limiting layer; 34-Encapsulation layer; 4-Conductive pillar; 5-Adhesive layer; 51-Hole structure. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0052] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] In related technologies, traditional AMOLED array processes are typically used to fabricate island-bridge structures, where pixel islands and stretched bridges are on the same plane. The stretched bridges are designed in a serpentine shape, deforming rather than stretching during the stretching process, thus ensuring overall stretchability. However, this island-bridge structure generally suffers from a constraint relationship between PPI and stretching ratio. For example, if the stretching ratio of the stretched bridge itself is α, and the proportion of the straight length of the stretched bridge to the total length is β, then the overall stretching ratio of the island-bridge structure is α*β. Here, the total length is the sum of the length of a pixel island and the length of the stretched bridge connected to it along a certain direction.

[0055] Therefore, in order to improve PPI without sacrificing stretchability, it is necessary to modify the effect of island area on stretchability through special design. This application provides a stretchable display panel that achieves both high stretchability and high PPI by placing pixel islands and stretch bridges on two different planes.

[0056] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0057] Please see Figures 1 to 2 , Figure 1 A simplified structural diagram of a stretchable display panel provided in one embodiment of this application; Figure 2 for Figure 1 The diagram shows a specific structural schematic at point A of the stretchable display panel. In this embodiment, a stretchable display panel 10 is provided, which can be applied to flexible wearables, irregularly shaped displays, 3D teaching models, medical electronic skin, etc. The stretchable display panel 10 includes a stretchable substrate 1, stretchable wires 2, pixel islands 3, and conductive pillars 4.

[0058] The stretchable substrate 1 includes multiple carrier regions 11 and multiple bridging regions 12. The multiple carrier regions 11 are spaced apart, and adjacent carrier regions 11 are connected by bridging regions 12. There are multiple pixel islands 3 and multiple stretchable wires 2. The multiple stretchable wires 2 and multiple pixel islands 3 are respectively disposed on the stretchable substrate 1, and the multiple pixel islands 3 are respectively located in multiple carrier regions 11 of the stretchable substrate 1. A portion of the stretchable wire 2 is located in the bridging region 12, and a portion of the stretchable wire 2 extends into the carrier region 11 of the stretchable substrate 1 adjacent to the bridging region 12 where the stretchable wire 2 is located.

[0059] In some embodiments, one pixel island 3 is provided for each carrier area 11. Two pixel islands 3 of adjacent carrier areas 11 are electrically connected by a stretchable wire 2. Adjacent pixel islands 3 are interconnected by the stretchable wire 2, enabling the transmission of electrical signals or other signals between them.

[0060] The connection method between the stretchable wire 2 and the pixel island 3 is not limited here. Both ends of the stretchable wire 2 are connected to the pixel island 3, or one end of the stretchable wire 2 is connected to the pixel island 3. The number of stretchable wires 2 connected to the pixel island 3 is not limited here. The pixel island 3 may have only one stretchable wire 2 connected to it, or it may have two or more stretchable wires 2 connected to it.

[0061] Among them, the stretchable conductors 2 located in different bridging zones 12 are insulated; for example, the stretchable conductors 2 located in different bridging zones 12 are spaced apart.

[0062] The stretchable substrate 1 is made of one or more of the following materials: polydimethylsiloxane (PDMS), polyurethane (TPU), block copolymer (SBS, SEBS), and polyacrylic elastomer (VHB series).

[0063] The stretchable conductor 2 is specifically curved; for example, it can be snake-shaped, wavy, or pleated. The small local deformation of the curved stretchable conductor 2 can achieve a large cumulative deformation to realize the stretchable display. By being curved, the stretchable conductor 2 has a long trace length, which can effectively release stress during external stretching, avoid large deformation of the trace that causes sudden changes in resistance value, and thus avoid unstable changes in the brightness of the optical display, as well as uneven brightness during stretching.

[0064] The stretchable wire 2 includes metal nanowires, conductive composite materials, or liquid metal, etc. The metal nanowires can be silver nanowires, copper nanowires, etc.

[0065] Combination Figure 1 Each pixel island 3 includes a substrate 31 and a light-emitting unit 32 disposed on the substrate 31. The light-emitting unit 32 is used for display. A portion of the substrate 31 is disposed on the surface of the stretchable wire 2 facing away from the stretchable substrate 1, and the substrate 31 has a conductive hole 310. In some embodiments, combined with Figure 1 The orthographic projection of the conductive hole 310 along the stacking direction Y of the stretchable display panel 10 falls on the stretchable wire 2; this is taken as an example in all embodiments of this application. Of course, in some other embodiments, the orthographic projection of the conductive hole 310 along the stacking direction Y of the stretchable display panel 10 may also fall on the stretchable substrate 1, and the conductive hole 310 and the stretchable wire 2 are arranged adjacent to each other in a direction perpendicular to the stacking direction Y of the stretchable display panel 10, so that the conductive post 4 provided in the conductive hole 310 can make contact and electrical connection with the stretchable wire 2.

[0066] The conductive post 4 has a certain self-supporting strength. It is inserted into the conductive hole 310 of the substrate 31 and electrically connected to the stretchable wire 2 and the light-emitting unit 32. Specifically, the cross-sectional area of ​​the conductive post 4 can be slightly smaller than the cross-sectional area of ​​the conductive hole 310 to facilitate insertion. Alternatively, the cross-sectional area of ​​the conductive post 4 can be equal to the cross-sectional area of ​​the conductive hole 310.

[0067] The conductive pillar 4 can be made of any material with conductive properties, such as conductive metals like copper or silver. The extension direction of the conductive pillar 4 can be perpendicular to the stretchable substrate 1. Specifically, the conductive pillar 4 can be cylindrical, conical, or wedge-shaped. Specifically, multiple conductive pillars 4 are disposed on the stretchable substrate 1, and these multiple conductive pillars 4 can be arranged in an array.

[0068] In some embodiments, the conductive post 4 is disposed on the surface of the stretchable wire 2 facing away from the stretchable substrate 1. Of course, in other embodiments, the conductive post 4 may also be disposed on the stretchable substrate 1, and the conductive post 4 is adjacent to and in contact with the stretchable wire 2, so that the conductive post 4 and the stretchable wire 2 are electrically connected.

[0069] Specifically, such as Figure 1 As shown, the substrate 31 includes a first electrode and a second electrode; each electrode corresponds to a conductive hole 310 and a stretchable wire 2. The light-emitting unit 32 is electrically connected to two adjacent pixel islands 3 through the two different electrodes, the first electrode and the second electrode. Taking the first electrode as an example, the stretchable wire 2 is in direct or indirect contact with and electrically connected to the first electrode through the conductive post 4 in the corresponding conductive hole 310; the first electrode is electrically connected to the light-emitting unit 32, so that the light-emitting unit 32 is electrically connected to an adjacent pixel island 3 through the first electrode, the conductive post 4, and the stretchable wire 2.

[0070] In some embodiments, such as Figure 2 As shown, the substrate 31 includes a substrate island 311, an active layer 312, a gate insulating layer 313 (GI), a first metal layer 314 (M1), an interlayer insulating layer 315 (CI), a second metal layer 316 (M2), an interlayer dielectric layer 317 (ILD), a third metal layer 318 (M3), and a planarization layer 319 (PLN) disposed sequentially. The active layer 312 is disposed on the substrate island 311; the gate insulating layer 313 is disposed on the active layer 312. The first metal layer 314 is disposed on the gate insulating layer 313, and the first metal layer 314 includes a signal transmission layer and a gate for a driving circuit. The interlayer insulating layer 315 is disposed on the first metal layer 314. The second metal layer 316 is disposed on the interlayer insulating layer 315, and portions of the second metal layer 316 and the first metal layer 314 form the upper and lower plates of a capacitor. The interlayer dielectric layer 317 is disposed on the second metal layer 316. A third metal layer 318 is disposed on the interlayer dielectric layer 317, and the third metal layer 318 includes a source and a drain of the driving circuit; one of the source and drain is electrically connected to the light-emitting unit 32, and the other is electrically connected to the signal transmission layer. A planarization layer 319 is disposed on the third metal layer 318 and planarizes the surface of one side of the third metal layer 318. The first electrode and the second electrode can be a portion of the first metal layer 314, a portion of the second metal layer 316, or a portion of the third metal layer 318, respectively. Specifically, the first electrode and the second electrode can each include one or more of a source, a power line, and a signal line.

[0071] The gate insulating layer 313, the interlayer insulating layer 315, the interlayer dielectric layer 317, and the planarization layer 319 can all be made of at least one inorganic material such as silicon oxide (SiOx) and silicon nitride (SiNx). Of course, a buffer layer can also be provided on the substrate island 311, and the active layer 312 is disposed on the buffer layer.

[0072] In the above scheme, the stretchable wire 2 is electrically connected to the source or drain of the driving circuit through the conductive post 4 in the conductive hole 310, and is electrically connected to the light-emitting unit 32 through the driving circuit; this can ensure the normal function of the stretchable display panel 10 while giving the stretchable wire 2 a greater stretching ratio, thereby obtaining a stretchable display panel 10 with a high stretching ratio.

[0073] In one embodiment, such as Figure 2 As shown, the conductive via 310 penetrates the substrate island 311 and the gate insulating layer 313. One end of the conductive post 4 contacts and is electrically connected to the stretchable wire 2, and the other end of the conductive post 4 is inserted into the conductive via 310 and abuts against and is electrically connected to the signal transmission layer of the first metal layer 314. Further, a first conductive via is formed on the substrate 31, extending from the surface of the interlayer dielectric layer 317 toward the third metal layer 318 to the surface of the signal transmission layer, thereby electrically connecting the signal transmission layer and the third metal layer 318.

[0074] In another embodiment, see Figure 3 , Figure 3 for Figure 1 Another specific structural diagram of point A of the stretchable display panel is shown; a portion of the second metal layer 316 extends between the signal transmission layer and the third metal layer 318. A second conductive hole and a third conductive hole are formed on the substrate 31; the second conductive hole extends from the surface of the interlayer insulating layer 315 facing the second metal layer 316 to the surface of the signal transmission layer, electrically connecting the signal transmission layer and the second metal layer 316. The third conductive hole extends from the surface of the interlayer dielectric layer 317 facing the third metal layer 318 to the surface of the second metal layer 316, electrically connecting the second metal layer 316 and the third metal layer 318. This solution, compared to... Figure 2 In the scheme shown, the depths of the second and third conductive holes are both less than the depth of the first conductive hole, which facilitates the filling of conductive material into the conductive holes to achieve electrical connection between adjacent metal layers.

[0075] In some embodiments, such as Figure 2 or Figure 3As shown, the light-emitting unit 32 includes an anode 321, a light-emitting functional layer 322, and a cathode 323. The pixel island 3 also includes a pixel defining layer 33 and an encapsulation layer 34. The anode 321 is disposed on the planarization layer 319 and electrically connected to the source or drain of the driving circuit. The pixel defining layer 33 is disposed on the planarization layer 319, covering a portion of the anode 321 and defining multiple pixel openings. A portion of the anode 321 is exposed through the pixel openings. The light-emitting functional layer 322 is disposed on the anode 321 and electrically connected to the anode 321; and the light-emitting functional layer 322 is located within the pixel openings. The cathode 323 is disposed on the surface of the light-emitting functional layer 322 facing away from the anode 321. The encapsulation layer 34 covers the pixel defining layer 33 and the cathode 323, and is used to encapsulate the surface of the pixel island 3 to prevent external moisture and other contaminants from entering the interior of the pixel island 3 and affecting the display effect.

[0076] In some embodiments, see Figure 4 , Figure 4 This is a schematic diagram of the structure of a stretchable display panel according to another embodiment of this application; the stretchable display panel 10 further includes an adhesive layer 5. The adhesive layer 5 is disposed on the stretchable substrate 1. The stretchable wires 2 are adhered to the surface of the adhesive layer 5 facing away from the stretchable substrate 1. A portion of the pixel islands 3 is adhered to the adhesive layer 5.

[0077] The adhesive layer 5 is provided with multiple hole structures 51. The orthographic projection of the pixel island 3 onto the stretchable substrate 1 covers at least a portion of the orthographic projection of the multiple hole structures 51 onto the stretchable substrate 1. In this way, on the one hand, the adhesive layer 5 can increase the adhesion between the stretchable substrate 1 and the stretchable wire 2 and the pixel island 3, reducing the probability of the stretchable wire 2 slipping relative to the stretchable substrate 1 during stretching or reducing the slippage range; on the other hand, the hole structures 51 of the adhesive layer 5 can buffer the interface stress concentration between the pixel island 3 and the stretchable substrate 1 during stretching.

[0078] In some embodiments, the orthographic projection of the pixel island 3 onto the stretchable substrate 1 covers the entire orthographic projection of the plurality of hole structures 51 onto the stretchable substrate 1.

[0079] The perforated structure 51 has a cross-section in a direction perpendicular to the stacking direction Y of the stretchable display panel 10, which may be a strip, circle, ellipse, polygon, or irregular shape. The adhesive layer 5 is made of materials such as polydopamine (PDA), polyvinylpropyl dimethylammonium chloride (PDDA), and polyurethane urea (PUU).

[0080] The stretchable display panel 10 provided in this embodiment includes: a stretchable substrate 1, stretchable conductive lines 2, pixel islands 3, and conductive pillars 4; wherein, the stretchable conductive lines 2 are disposed on the stretchable substrate 1; the pixel islands 3 include a substrate 31 and light-emitting units 32 disposed on the substrate 31; the substrate 31 is disposed on the stretchable substrate 1 and has conductive holes 310; the conductive pillars 4 are inserted into the conductive holes 310 and electrically connect the stretchable conductive lines 2 and the light-emitting units 32 respectively. This stretchable display panel 10 arranges the stretchable conductive lines 2 and the light-emitting units 32 on two different planes and electrically connects the light-emitting units 32 and the stretchable conductive lines 2 through the conductive pillars 4; thus, the stretchable conductive lines 2 do not occupy the distribution space of the light-emitting units 32, allowing for a denser distribution of the light-emitting units 32, thereby improving the display PPI. Furthermore, the light-emitting units 32 do not occupy the distribution space of the stretchable conductive lines 2, allowing for a denser distribution of the stretchable conductive lines 2, thereby improving the stretchability of the stretchable conductive lines 2. In addition, by setting the stretchable wire 2 to a curved shape, the overall stretchability of the stretchable display panel 10 can be further improved, so that the stretchable display panel 10 can achieve both high stretchability and high PPI.

[0081] See Figure 5 , Figure 5 This is a flowchart illustrating a method for fabricating a stretchable display panel according to an embodiment of this application. This method can be used to fabricate the stretchable display panel 10 provided in the above embodiment. The method includes:

[0082] Step S1: Provide a stretchable substrate and a pixel island; the pixel island includes a substrate and a light-emitting unit stacked together; and the substrate has conductive holes.

[0083] The stretchable substrate 1 includes multiple carrier regions 11 and multiple bridging regions 12. The multiple carrier regions 11 are spaced apart and adjacent carrier regions 11 are connected by bridging regions 12. The material of the stretchable substrate 1 includes one or more of polydimethylsiloxane (PDMS), polyurethane (TPU), block copolymers (SBS, SEBS), and polyacrylic elastomers (VHB series).

[0084] The light-emitting unit 32 is used for display. The substrate 31 includes a substrate island 311, an active layer 312, a gate insulating layer 313, a first metal layer 314, an interlayer insulating layer 315, a second metal layer 316, an interlayer dielectric layer 317, a third metal layer 318, and a planarization layer 319, which are sequentially disposed. The positional relationship between the various layers can be found above. The conductive via 310 is a blind via structure formed on the substrate 31. Specifically, the conductive via 310 penetrates the substrate island 311 and the gate insulating layer 313.

[0085] In some embodiments, the pixel island 3 further includes a pixel defining layer 33 and an encapsulation layer 34. See above for details.

[0086] In some implementations, see Figure 6 , Figure 6 This is a schematic diagram of a structure for providing an adhesive layer on a stretchable substrate according to an embodiment of this application; after step S1, it further includes:

[0087] Step A: Apply an adhesive layer 5 to the stretchable substrate 1.

[0088] An adhesive layer 5 can be applied to the surface of the stretchable substrate 1 using methods such as printing, bonding, or lamination. The adhesive layer 5 can cover the entire surface of the stretchable substrate 1 to adhere and fix the stretchable wires 2 and pixel islands 3 formed later. Materials for the adhesive layer 5 include polydopamine (PDA), polyvinylpropyl dimethylammonium chloride (PDDA), and polyurethane urea (PUU).

[0089] In some implementations, see Figure 7 , Figure 7 To Figure 6 A schematic diagram of the product structure after graphical processing of the structure shown; after step A, it also includes:

[0090] Step B: The adhesive layer 5 is patterned to form multiple hole structures 51 on the adhesive layer 5.

[0091] In this process, at least a portion of the orthographic projection of the plurality of hole structures 51 onto the stretchable substrate 1 falls on the bearing region 11 of the stretchable substrate 1. After performing step S3, when the pixel island 3 is disposed on the stretchable substrate 1, the orthographic projection of the pixel island 3 onto the stretchable substrate 1 covers at least a portion of the orthographic projection of the plurality of hole structures 51 onto the stretchable substrate 1. Thus, after performing step S3, the hole structures 51 of the adhesive layer 5 can buffer the interfacial stress concentration between the pixel island 3 and the stretchable substrate 1 during the stretching process.

[0092] Preferably, the orthographic projections of the plurality of hole structures 51 onto the stretchable substrate 1 all fall on the bearing area 11 of the stretchable substrate 1. The orthographic projection of the pixel island 3 onto the stretchable substrate 1 covers the entire orthographic projection of the plurality of hole structures 51 onto the stretchable substrate 1. The following embodiments of this application all use... Figure 7 The corresponding embodiments will be used as examples for illustration.

[0093] The cross-section of the hole structure 51 along the direction perpendicular to the stacking direction Y of the stretchable display panel 10 has a shape including strip, circle, ellipse, polygon or irregular shape.

[0094] Next, proceed to step S2.

[0095] Step S2: Form a bent stretchable wire on the stretchable substrate.

[0096] In some specific embodiments, step S2 specifically includes:

[0097] Step S21: Apply a tensile force to the stretchable substrate 1.

[0098] Specifically, a tensile force can be applied to one or both ends of the stretchable substrate 1 along its stretchable direction to increase its length. Once the length of the stretchable substrate 1 reaches a preset length, stretching is stopped, and the stretchable substrate 1 is maintained at the current preset length. Specifically, a tensile force can be applied to the stretchable substrate 1 using a tensioning device. After the stretchable substrate 1 is stretched to the preset length, the tensioning device stops stretching the stretchable substrate 1 and maintains it at the current preset length.

[0099] Of course, in other embodiments, after the stretchable substrate 1 is stretched to a preset length, it can also be connected to both ends of the stretchable length by other fixing devices to maintain the length of the stretchable substrate 1 at the current preset length. The preset length can be set according to actual needs.

[0100] Step S22: Form a stretchable wire 2 on the stretchable substrate 1.

[0101] See Figure 8 , Figure 8 This is a simplified planar schematic diagram of a stretchable wire formed on a stretchable substrate according to an embodiment of this application. The stretchable wire 2 can be fabricated on the stretchable substrate 1 by means of printing or screen printing.

[0102] Step S23: Release the tensile force on the stretchable substrate 1 to make the stretchable wire 2 bend.

[0103] See Figure 9 and Figure 10 , Figure 9 for Figure 8 The diagram shows the product structure after the stretchable substrate has released its tensile force. Figure 10 for Figure 9 The diagram shows a vertical cross-sectional view of the structure. It can be understood that after the tensile force is released, the stretchable wires 2 on the stretched stretchable substrate 1 will retract along with the stretchable substrate 1, causing the stretchable wires 2 to become wrinkled and bent, thereby increasing the overall stretchability of the formed stretchable display panel. This can be achieved by loosening the two ends of the stretchable substrate 1 using the tensioning device, or by loosening the two ends of the stretchable substrate 1 using other fixing devices, thus releasing the tensile force exerted on the stretchable substrate 1 by the fixing devices.

[0104] Specifically, part of the stretchable wire 2 is located in the bridging area 12, and part of the stretchable wire 2 is located in the bearing area 11; thus, conductive posts 4 can be formed on the stretchable wire 2 located in the bearing area 11 to increase the contact area between the conductive posts 4 and the stretchable wire 2 and improve the contact yield between the two.

[0105] The stretchable conductors 2 corresponding to each two adjacent bridging zones 12 are insulated, for example, spaced apart.

[0106] In some embodiments, the stretchable wire 2 comprises metal nanowires; after the step of forming the stretchable wire 2 on the stretchable substrate 1, the method further includes: thermally annealing, or capillary force or laser treatment of the metal nanowires to weld the joined metal nanowires. This can reduce the contact resistance of the joined metal nanowires and increase the stretchability of the stretchable wire 2. This step can be performed after step 23, or after step S22 and before step S23.

[0107] When an adhesive layer 5 is provided on the stretchable substrate 1, step S22 specifically involves providing the stretchable wire 2 on the adhesive layer 5. Compared to the method of directly forming the stretchable wire 2 on the stretchable substrate 1, the adhesive layer 5 can increase the adhesion between the stretchable substrate 1 and the stretchable wire 2, thereby reducing the probability of the stretchable wire 2 slipping relative to the stretchable substrate 1 during the stretching process or reducing the slippage range.

[0108] Step S3: Form conductive pillars on the stretchable substrate or in the conductive hole, and place the pixel island on the stretchable substrate, and make the conductive pillars electrically connected to the stretchable wires and the light-emitting unit respectively.

[0109] In one implementation, see Figure 11 , Figure 11 This is a schematic diagram of a structure for forming conductive pillars on a stretchable substrate according to an embodiment of this application. Step S3 specifically includes:

[0110] Step S31a: A conductive post 4 is formed on the stretchable substrate 1 and / or the stretchable wire 2; the conductive post 4 contacts and is electrically connected to the stretchable wire 2.

[0111] Specifically, conductive pillars 4 with a certain self-supporting strength can be formed at predetermined positions on the stretchable substrate 1 and / or the stretchable wire 2 using methods such as 3D printing or electrohydrodynamic printing. Self-supporting means that the corresponding structure can maintain its current shape without the aid of other components.

[0112] The conductive pillar 4 is formed on the stretchable substrate 1. This can be done entirely on the stretchable substrate 1, or entirely on the stretchable wire 2, in which case the conductive pillar 4 is indirectly disposed on the stretchable substrate 1. Alternatively, a portion of the conductive pillar 4 can be formed on the stretchable substrate 1, with the remaining portion formed on the stretchable wire 2. If the conductive pillar 4 is formed on the stretchable wire 2, the width of the area where the conductive pillar 4 needs to be placed can be widened during the formation of the stretchable wire 2 to facilitate the placement of the conductive pillar 4 and increase the contact area between the conductive pillar 4 and the stretchable wire 2, ensuring effective electrical connection between the two.

[0113] If a conductive post 4 is formed on the stretchable substrate 1, that is, the conductive post 4 is disposed on the stretchable substrate 1, and the side of the conductive post 4 is in contact with the stretchable wire 2, so as to realize the electrical connection between the two.

[0114] The conductive pillar 4 can extend perpendicularly to the stretchable substrate 1. Specifically, the conductive pillar 4 can be cylindrical, conical, or wedge-shaped. More than one conductive pillar 4 can be disposed on the stretchable substrate 1, and these multiple conductive pillars 4 can be arranged in an array.

[0115] Step S32a: Align the conductive hole 310 of the pixel island 3 with the conductive post 4, and place the pixel island 3 on the stretchable substrate 1 so that the conductive post 4 is electrically connected to the light-emitting unit 32.

[0116] Combination Figure 1 and Figure 12 , Figure 12 This is a simplified three-dimensional structure diagram of the product after step S32a, provided in an embodiment of this application; after the pixel island 3 is disposed on the stretchable substrate 1, a portion of the pixel island 3 is bonded and fixed to the adhesive layer 5. The conductive pillar 4 forms a vertical conductive path between the stretchable wire 2 and the pixel island 3.

[0117] In this embodiment, multiple conductive pillars 4 are first formed on the stretchable substrate 1, and then the conductive holes 310 of the pixel island 3 are aligned with the conductive pillars 4 and attached to the stretchable substrate 1. This method can simultaneously form multiple conductive pillars 4 on the stretchable substrate 1, which is simple and efficient. At the same time, before the conductive pillars 4 are attached to the pixel island 3, it is convenient to store several conductive pillars 4 to prevent the conductive pillars 4 from being lost.

[0118] Of course, in other embodiments, step S3 may also include:

[0119] Step S31b: Form a conductive post 4 in each conductive hole 310 of the pixel island 3.

[0120] In one embodiment, the conductive post 4 may protrude from the side of the substrate 31 facing away from the light-emitting unit 32, so as to ensure that after the pixel island 3 is attached to the stretchable substrate 1, the conductive post 4 can effectively contact and electrically connect with the stretchable wire 2. Of course, the side of the conductive post 4 facing away from the light-emitting unit 32 may also be flush with the side of the substrate 31 facing away from the light-emitting unit 32.

[0121] Conductive pillars 4 can be formed in the conductive holes 310 by means of deposition, spraying, printing, etc.

[0122] Step S32b: Place the pixel island 3 on the stretchable substrate 1 and make the conductive post 4 contact the stretchable wire 2.

[0123] Wherein, after the pixel island 3 is disposed on the stretchable substrate 1, the side of the conductive post 4 contacts the stretchable wire 2, or at least a portion of the surface of the conductive post 4 facing away from the light-emitting unit 32 overlaps with the stretchable wire 2, so as to realize the electrical connection between the conductive post 4 and the stretchable wire 2.

[0124] Compared to the above embodiments, this embodiment requires lower alignment accuracy between the pixel island 3 and the stretchable substrate 1 during the bonding process.

[0125] The method for fabricating a stretchable display panel provided in this embodiment includes: providing a stretchable substrate 1 and a pixel island 3; the pixel island 3 includes a substrate 31 and light-emitting units 32 stacked together; and the substrate 31 has conductive holes 310; then forming a curved stretchable wire 2 on the stretchable substrate 1; subsequently, forming a conductive post 4 in the stretchable substrate 1 or the conductive hole 310, and placing the pixel island 3 on the stretchable substrate 1, and electrically connecting the stretchable wire 2 and the light-emitting unit 32 respectively with the conductive post 4. In this way, the stretchable wire 2 and the light-emitting unit 32 can be placed on two different planes, and by designing the conductive hole 310, the conductive post 4 is inserted into the conductive hole 310 to electrically connect the light-emitting unit 32 and the stretchable wire 2 located on different planes; wherein, the stretchable wire 2 does not occupy the distribution space of the light-emitting unit 32, and a relatively dense distribution of the light-emitting unit 32 can be achieved, thereby improving the display PPI. In addition, the light-emitting unit 32 does not occupy the distribution space of the stretchable wire 2, and a relatively dense distribution of the stretchable wire 2 can be achieved, thereby improving the stretchability of the stretchable wire 2. In addition, by setting the stretchable wire 2 to a curved shape, the overall stretchability of the obtained stretchable display panel 10 can be further improved; thus, the stretchable display panel 10 prepared by this method achieves both high stretchability and high PPI.

[0126] See Figure 13 , Figure 13This is a simplified structural diagram of a stretchable display device provided in one embodiment of this application. In this embodiment, a stretchable display device is provided, comprising a stretchable display panel 10. The stretchable display panel 10 is the stretchable display panel 10 provided in the above embodiments; or the stretchable display panel 10 is manufactured by the method for preparing the stretchable display panel provided in the above embodiments. The specific structure and function of the stretchable display panel 10 can be found in the above descriptions and will not be repeated here. The electronic device can be a mobile phone, tablet computer, laptop computer, television, or other product or component with display functionality. The electronic device also includes a motherboard, control circuitry, etc., whose structures are the same as or similar to those of existing display devices; specific details can be found in the prior art and will not be repeated here.

[0127] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A stretchable display panel, characterized in that, include: Stretchable substrate; A stretchable wire is disposed on the stretchable substrate; A pixel island includes a substrate and light-emitting units disposed on the substrate; The substrate is disposed on the stretchable substrate; and the substrate has conductive holes; The conductive post is inserted into the conductive hole and electrically connected to the stretchable wire and the light-emitting unit, respectively.

2. The stretchable display panel according to claim 1, characterized in that, Also includes: An adhesive layer is disposed on the stretchable substrate; the stretchable wires and the pixel islands are adhered to the adhesive layer on the side surface facing away from the stretchable substrate. Preferably, the adhesive layer has a plurality of porous structures; The orthographic projection of the pixel island onto the stretchable substrate covers at least a portion of the orthographic projection of the plurality of hole structures onto the stretchable substrate; Preferably, the cross-section of the hole structure along the direction perpendicular to the stacking direction of the stretchable display panel is strip-shaped, circular, elliptical, polygonal, or irregular.

3. The stretchable display panel according to claim 1, characterized in that, The stretchable conductor is curved; Preferably, the conductive post is disposed on the surface of the stretchable wire away from the stretchable substrate; Preferably, the extension direction of the conductive pillar is perpendicular to the stretchable substrate; Preferably, the conductive post is cylindrical, conical, or wedge-shaped; Preferably, there are multiple conductive pillars, which are arranged in an array.

4. The stretchable display panel according to claim 1, characterized in that, The number of pixel islands and stretchable wires are both multiple; the stretchable substrate includes multiple carrier areas and multiple bridging areas, the multiple carrier areas are spaced apart and adjacent two carrier areas are connected through the bridging areas; the multiple stretchable wires are respectively disposed in the multiple bridging areas, and the multiple pixel islands are respectively disposed in the multiple carrier areas; adjacent two pixel islands are connected through the stretchable wires; the stretchable wires located in different bridging areas are insulated; Preferably, the stretchable conductors located in different bridging zones are spaced apart.

5. A method for manufacturing a stretchable display panel, characterized in that, include: Provides stretchable substrates and pixel islands; The pixel island comprises a substrate and light-emitting units stacked together; and the substrate has conductive holes. A curved stretchable wire is formed on the stretchable substrate; Conductive pillars are formed on the stretchable substrate or in the conductive holes, and the pixel islands are disposed on the stretchable substrate, with the conductive pillars electrically connected to the stretchable wires and the light-emitting unit, respectively.

6. The method for manufacturing a stretchable display panel according to claim 5, characterized in that, The step of forming a bent, stretchable wire on the stretchable substrate includes: A tensile force is applied to the stretchable substrate; Stretchable wires are formed on the stretchable substrate; Release the tensile force on the stretchable substrate to cause the stretchable wire to bend.

7. The method for preparing a stretchable display panel according to claim 5, characterized in that, The step of forming conductive pillars on the stretchable substrate or within the conductive hole, and disposing the pixel island on the stretchable substrate so that the conductive pillars are electrically connected to the stretchable wires and the light-emitting unit respectively, includes: Conductive pillars are formed on the stretchable substrate and / or the stretchable wire; the conductive pillars are in contact with and electrically connected to the stretchable wire. Align the conductive holes of the pixel island with the conductive pillars, and place the pixel island on the stretchable substrate so that the conductive pillars are electrically connected to the light-emitting unit; Preferably, the extension direction of the conductive pillar is perpendicular to the stretchable substrate; Preferably, the conductive hole is a blind hole structure formed on the substrate.

8. The method for manufacturing a stretchable display panel according to claim 5, characterized in that, Prior to the step of forming bent, stretchable wires on the stretchable substrate, the method further includes: An adhesive layer is disposed on the stretchable substrate; the stretchable wire and the pixel island are disposed on the side surface of the adhesive layer opposite to the stretchable substrate.

9. The method for manufacturing a stretchable display panel according to claim 8, characterized in that, After the step of forming the adhesive layer, the method further includes: The adhesive layer is patterned to form a plurality of hole structures on the adhesive layer; wherein, when the pixel island is disposed on the stretchable substrate, the orthographic projection of the pixel island on the stretchable substrate covers at least a portion of the orthographic projection of the plurality of hole structures on the stretchable substrate; Preferably, the cross-section of the hole structure along the direction perpendicular to the stacking direction of the stretchable display panel is strip-shaped, circular, elliptical, polygonal, or irregular. Preferably, the orthographic projection of the pixel island on the stretchable substrate covers the entire orthographic projection of the plurality of hole structures on the stretchable substrate; Preferably, the stretchable substrate includes multiple carrier regions and multiple bridging regions, the multiple carrier regions are spaced apart and adjacent carrier regions are connected through the bridging regions; the pixel island is located in the carrier region; a portion of the stretchable wire is located in the bridging region and a portion of the stretchable wire is located in the carrier region.

10. A stretchable display device, characterized in that, It includes a stretchable display panel; the stretchable display panel is the stretchable display panel as described in any one of claims 1-4; or the stretchable display panel is prepared by the method for preparing a stretchable display panel as described in any one of claims 5-9.

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