A stretchable display substrate and a preparation method thereof, and a display device

Abstract

The embodiments of the present disclosure disclose a stretchable display substrate and a preparation method thereof, and a display device, including multiple hole areas; the stretchable display substrate includes: a substrate; a pixel unit, which is arranged on the substrate; a signal line, which is arranged on the substrate and electrically connected to the pixel unit; a plurality of inorganic insulating layers, which are stacked on the substrate, at least one layer of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and the orthographic projection of the first hollow portion on the substrate does not overlap with the orthographic projection of the signal line and the pixel unit on the substrate.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a stretchable display substrate and a preparation method thereof, and a display device. Background Art

[0002] With the development of display technology, organic light-emitting diodes (OLEDs) capable of flexible display have promoted the diversification of display and gradually become the mainstream of display technology. In some related technologies, OLED flexible display devices can meet the bending of two-dimensional surfaces, but are not suitable for display devices with more complex situations (such as wearable devices, etc.) that require flexibility for stretchable display substrates.

[0003] In order to develop stretchable OLED display functions, some related technologies open holes in the substrate material of the OLED flexible display device to form islands for preparing pixel areas and bridges for routing, and the stretching of the display device is achieved through the deformation of the bridges. Summary of the invention

[0004] The present disclosure provides a stretchable display substrate, including a plurality of hole areas; the stretchable display substrate includes:

[0005] substrate;

[0006] A pixel unit is arranged on the substrate;

[0007] A signal line, disposed on the substrate and electrically connected to the pixel unit;

[0008] A plurality of inorganic insulating layers are stacked on the substrate, at least one of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and the orthographic projection of the first hollow portion on the substrate does not overlap with the orthographic projection of the signal line and the pixel unit on the substrate.

[0009] Optionally, in the above-mentioned stretchable display substrate provided in the embodiment of the present disclosure, it further includes: a plurality of pixel island regions spaced apart between the hole regions, and a connecting bridge region between the pixel island regions and the hole regions;

[0010] The connecting bridge area includes at least one pixel unit, the first hollow portion is located in the connecting bridge area, and the first hollow portion is located between the pixel unit in the connecting bridge area and the hole area.

[0011] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the connecting bridge area includes a plurality of the pixel units, and the orthographic projection of the signal line on the substrate is at least located within the pixel units of the connecting bridge area and the orthographic projection of the area between the pixel units of the connecting bridge area on the substrate.

[0012] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, an extension direction of the first hollow portion is substantially the same as an edge of the hole area.

[0013] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the first hollow portion is not connected to the hole area.

[0014] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, a distance between a side wall of the first hollow portion close to the hole area and a side wall of the hole area close to the first hollow portion is greater than or equal to 2 μm.

[0015] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, in a direction from the pixel island area to the hole area, a width of the first hollow portion is greater than or equal to 5 um.

[0016] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the first hollow portion and the hole area are interconnected.

[0017] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, an edge of the first hollow portion close to the hole area overlaps with an edge of the hole area close to the first hollow portion.

[0018] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the pixel unit includes at least one sub-pixel, the sub-pixel includes a pixel circuit and a light-emitting device, the light-emitting device includes a stacked anode, an organic light-emitting layer and a cathode; a partition structure is provided in the connection bridge area near the pixel unit, the organic light-emitting layer is disconnected at the partition structure, and the cathode is disconnected at the partition structure;

[0019] The distance between the side wall of the first hollow portion close to the pixel unit and the partition structure is greater than or equal to 2 um.

[0020] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the first hollow portion is a closed structure arranged around the hole area.

[0021] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the partition structure is a closed structure arranged around the first hollow portion.

[0022] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, a part of the hole area includes: a first sub-hole area and a second sub-hole area extending along the first direction and arranged along the second direction, and a third sub-hole area extending along the second direction; another part of the hole area includes: a fourth sub-hole area and a fifth sub-hole area extending along the second direction and arranged along the first direction, and a sixth sub-hole area extending along the first direction; the first direction and the second direction are substantially perpendicular, the third sub-hole area substantially connects the central areas of the first sub-hole area and the second sub-hole area, and the sixth sub-hole area substantially connects the central areas of the fourth sub-hole area and the fifth sub-hole area;

[0023] The first hollow portion is at least arranged at at least one of the following positions: one side of the connection position between the first sub-hole area and the third sub-hole area, one side of the connection position between the second sub-hole area and the third sub-hole area, one side of the end of the first sub-hole area and one side of the end of the second sub-hole area, one side of the connection position between the fourth sub-hole area and the sixth sub-hole area, one side of the connection position between the fifth sub-hole area and the sixth sub-hole area, one side of the end of the fourth sub-hole area and one side of the end of the fifth sub-hole area.

[0024] Optionally, in the above-mentioned stretchable display substrate provided in the embodiment of the present disclosure, the first hollow portion is provided on one side of the connection position between the first sub-hole area and the third sub-hole area, on one side of the connection position between the second sub-hole area and the third sub-hole area, on one side of the end of the first sub-hole area and on one side of the end of the second sub-hole area, on one side of the connection position between the fourth sub-hole area and the sixth sub-hole area, on one side of the connection position between the fifth sub-hole area and the sixth sub-hole area, on one side of the end of the fourth sub-hole area and on one side of the end of the fifth sub-hole area.

[0025] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the pixel island area includes at least one pixel unit, and the pixel resolution of the pixel island area is substantially the same as the pixel resolution of the connecting bridge area.

[0026] Optionally, in the above-mentioned stretchable display substrate provided in the embodiment of the present disclosure, the multiple inorganic insulating layers include a first barrier layer, a buffer layer, a first gate insulating layer, a second gate insulating layer, an interlayer dielectric layer, a first passivation layer, a second passivation layer and an inorganic packaging layer stacked on the substrate, and the first hollow portion is set in at least one of the first barrier layer, the buffer layer, the first gate insulating layer, the second gate insulating layer, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic packaging layer.

[0027] Optionally, in the above-mentioned stretchable display substrate provided in the embodiment of the present disclosure, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer are all provided with the first hollow portions, and the first hollow portions are substantially overlapped.

[0028] Optionally, in the above-mentioned stretchable display substrate provided by an embodiment of the present disclosure, the inorganic encapsulation layer includes a first inorganic layer and a second inorganic layer stacked on the second passivation layer;

[0029] The stretchable display substrate further includes: a first planar layer and a second planar layer located between the interlayer dielectric layer and the first passivation layer, a pixel defining layer located between the second passivation layer and the inorganic encapsulation layer, and an organic layer located between the first inorganic layer and the second inorganic layer;

[0030] At least one of the first planar layer, the second planar layer, the pixel defining layer and the organic layer has a second hollow portion near the hole region, and the first hollow portion and the second hollow portion substantially overlap.

[0031] Optionally, in the above-mentioned stretchable display substrate provided in an embodiment of the present disclosure, the base includes a flexible layer, or the base includes a first flexible layer, a second barrier layer and a second flexible layer stacked on a side of the first barrier layer away from the buffer layer.

[0032] Correspondingly, an embodiment of the present disclosure also provides a display device, comprising the above-mentioned stretchable display substrate.

[0033] Accordingly, the present disclosure also provides a method for preparing the above-mentioned stretchable display substrate, comprising:

[0034] providing a substrate;

[0035] forming a pixel unit and a signal line electrically connected to the pixel unit on the substrate;

[0036] A plurality of inorganic insulating layers are stacked on the substrate; wherein at least one of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and the orthographic projection of the first hollow portion on the substrate does not overlap with the orthographic projection of the signal line and the pixel unit on the substrate.

[0037] Optionally, in the above-mentioned preparation method provided by the embodiment of the present disclosure, at least one layer of the plurality of inorganic insulating layers has a first hollow portion near the hole area, specifically comprising:

[0038] Depositing a first barrier layer, a buffer layer, a first gate insulating layer, a second gate insulating layer, an interlayer dielectric layer, a first passivation layer, a second passivation layer and an inorganic encapsulation layer on the substrate;

[0039] The first hollow portion is formed in at least one of the first barrier layer, the buffer layer, the first gate insulating layer, the second gate insulating layer, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer by using a patterning process. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic top view of a stretchable display substrate provided in an embodiment of the present disclosure;

[0041] Figure 2 A schematic top view of another stretchable display substrate provided in an embodiment of the present disclosure;

[0042] Figure 3 for Figure 1 Schematic diagram of the cross section along the AA' direction;

[0043] Figure 4 for Figure 2 Schematic diagram of the cross section along the AA' direction;

[0044] Figure 5 A flow chart of a method for manufacturing a stretchable display substrate provided in an embodiment of the present disclosure;

[0045] Figure 6 A flow chart of a method for manufacturing a stretchable display substrate provided in another embodiment of the present disclosure;

[0046] Figure 7A-7K A structural schematic diagram of executing each step of the method for manufacturing a stretchable display substrate provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the specific implementation of the method for manufacturing a stretchable display substrate provided by the embodiment of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described below are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure. And in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0048] The thickness, size and shape of each film layer in the drawings do not reflect the actual proportion of the stretchable display substrate, and the purpose is only to illustrate the contents of the present disclosure.

[0049] The present disclosure provides a stretchable display substrate. Figure 1 and Figure 2 As shown, it includes a plurality of hole areas Q2; specifically, the hole area Q2 is used to provide a deformation space for the display substrate when it is stretched.

[0050] Specifically, Figure 3 and Figure 4 As shown, Figure 3 for Figure 1 Schematic diagram of the cross section of the structure along the AA' direction. Figure 4 for Figure 2 The cross-sectional schematic diagram of the partial structure along the AA' direction, the stretchable display substrate comprises:

[0051] Substrate 1; Substrate 1 may be a flexible substrate, so that the stretchable region of the stretchable display substrate can be stretched;

[0052] A pixel unit 4 is arranged on the substrate 1;

[0053] The signal line 2 is disposed on the substrate 1 and is electrically connected to the pixel unit 4; specifically, the signal line 2 may include a gate line, a data line, etc.;

[0054] A plurality of inorganic insulating layers are stacked on a substrate 1, at least one of the plurality of inorganic insulating layers has a first hollow portion 3 near the hole region Q2, and the orthographic projection of the first hollow portion 3 on the substrate 1 does not overlap with the orthographic projection of the signal line 2 and the pixel unit 4 on the substrate 1.

[0055] The above-mentioned stretchable display substrate provided by the embodiment of the present disclosure is subjected to tensile force and deformed at a position near the hole area Q2 when stretched. The present disclosure arranges at least one layer of the multiple inorganic insulating layers to have a first hollow portion 3 near the hole area Q2, that is, at least one layer of the multiple inorganic insulating layers is removed at a position near the hole area Q2. In this way, the buckling deformation behavior of the position near the hole area Q2 when stretched can be improved, so that the position near the hole area Q2 is not prone to breakage and the pixel unit 4 is not easily damaged, thereby improving the stretchability of the stretchable display substrate.

[0056] It should be noted that if Figure 1 and Figure 2 As shown, the hole area Q2 in the embodiment of the present disclosure may completely penetrate the stretchable display substrate. Of course, the hole area Q2 may also penetrate all the film layers on the base of the stretchable display substrate and part of the base.

[0057] It should be noted that if Figure 3 and Figure 4 As shown, the embodiment of the present disclosure is illustrated by taking the example that all inorganic insulating layers located on the substrate 1 are removed to form the first hollow portion 3. Of course, only any one inorganic insulating layer or multiple inorganic insulating layers may be removed to form the first hollow portion 3.

[0058] In the specific implementation, the stretchable panel with the island bridge structure design in the related art faces the problems of low display resolution (PPI) and uneven display. In the stretchable display substrate provided in the embodiment of the present disclosure, in order to improve the display resolution and improve the problem of uneven display, such as Figure 1-Figure 4 As shown, it also includes: a plurality of pixel island regions Q1 spaced apart between the hole regions Q2, and a connecting bridge region Q3 between the pixel island region Q1 and the hole region Q2; specifically, the pixel island region Q1 is used to display images, and the connecting bridge region Q3 is used for routing (to connect signals between adjacent pixel island regions Q1) and transmitting tension;

[0059] The connecting bridge area Q3 includes at least one pixel unit 4, the first hollow portion 3 is located in the connecting bridge area Q3, and the first hollow portion 3 is located between the pixel unit 4 in the connecting bridge area Q3 and the hole area Q2; that is, the present disclosure expands the original arrangement of pixel units only in the pixel island area Q1 to also arrange pixel units in the connecting bridge area Q3, thereby improving the display resolution and improving the problem of uneven display.

[0060] like Figure 1-Figure 4 As shown, the connection bridge area Q3 may include a plurality of pixel units 4, and the orthographic projection of the signal line 2 on the substrate 1 is at least located within the orthographic projection of the pixel units 4 in the connection bridge area Q3 and the area between the pixel units 4 in the connection bridge area Q3 on the substrate 1. That is, the signal line 2 is routed below the pixel units 4 in the connection bridge area Q3 and in the area between the pixel units 4, so that the various pixel units 4 are electrically connected.

[0061] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 1 As shown, the extension direction of the first hollow portion 3 is substantially the same as the edge of the hole region Q2. Thus, the first hollow portion 3 surrounding the hole region Q2 is arranged around the hole region Q2, further improving the stretchability of the stretchable display substrate.

[0062] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 As shown, the first hollow portion 3 is not connected to the hole area Q2. Since the first hollow portion 3 is formed in at least one layer of the multiple inorganic insulating layers, that is, multiple inorganic insulating layers are retained between the first hollow portion 3 and the hole area Q2, at least one layer of inorganic insulating layer is removed in the connecting bridge area Q3 to form the first hollow portion 3, which improves the buckling deformation behavior of the connecting bridge area Q3 when stretched, making it difficult for the connecting bridge area Q3 to break and the pixel island area Q1 adjacent to the connecting bridge area Q3 to be damaged, thereby improving the stretching performance of the stretchable display substrate.

[0063] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 As shown, the distance between the side wall of the first hollow portion 3 close to the hole region Q2 and the side wall of the hole region Q2 close to the first hollow portion 3 (the distance is the width of the inorganic insulating layer between the hole region Q2 and the first hollow portion 3) is greater than or equal to 2μm.

[0064] In order to reduce the difficulty of the manufacturing process during specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 As shown, along the direction from the pixel island area Q1 to the hole area Q2, the width of the first hollow portion 3 is greater than or equal to 5um, so that when the exposure, development and etching process is used to remove each inorganic insulating layer, the difficulty of the exposure, development and etching process can be reduced.

[0065] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 4 As shown, the first hollow portion 3 is interconnected with the hole area Q2, that is, when etching each inorganic insulating layer in the connecting bridge area Q3, the inorganic insulating layer of the connecting bridge area Q3 is directly etched to be connected with the hole area Q2, thereby further reducing the inorganic insulating layer of the connecting bridge area Q3, thereby further improving the tensile performance of the connecting bridge area Q3.

[0066] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 4 As shown, the edge of the first hollow portion 3 near the hole area Q2 overlaps with the edge of the hole area Q2 near the first hollow portion 3. That is, no inorganic insulating layer is retained between the first hollow portion 3 and the hole area Q2, that is, when etching each inorganic insulating layer in the connecting bridge area Q3, the inorganic insulating layer in the corresponding area of ​​the first hollow portion 3 is directly etched to the edge of the hole area Q2, further reducing the inorganic insulating layer in the connecting bridge area Q3, thereby further improving the tensile performance of the connecting bridge area Q3.

[0067] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 and Figure 4 As shown, the pixel unit 4 includes at least one sub-pixel, the sub-pixel includes a pixel circuit and a light-emitting device, the pixel circuit is located between the light-emitting device and the substrate 1, and the light-emitting device includes a stacked anode 6, an organic light-emitting layer 7 and a cathode 8; a partition structure 9 is provided near the pixel unit 4 in the connecting bridge area Q3, and the partition structure 9 is Figure 1 and Figure 2In the figure, the first hollow portion 3 is arranged around the first hollow portion 3, that is, the partition structure 9 is located between the pixel unit 4 and the first hollow portion 3, the organic light-emitting layer 7 is disconnected at the partition structure 9, and the cathode 8 is disconnected at the partition structure 9; because the partition structure 9 is located in the connecting bridge area Q3, and because the connecting bridge area Q3 is located between the hole area Q2 and the pixel island area Q1, that is, the organic light-emitting layer 7 and the cathode 8 separated by the partition structure 9 are partially located in the pixel island area Q1, and partially close to the hole area Q2, and the organic light-emitting layer 7 and the cathode 8 close to the hole area Q2 are easily invaded by water and oxygen. By dividing the organic light-emitting layer 7 and the cathode 8 into two mutually isolated parts, the isolation path distance of the water and oxygen invading the organic light-emitting layer 7 and the cathode 8 in the sub-pixel through the organic light-emitting layer 7 and the cathode 8 close to the hole area Q2 is effectively extended, that is, it is ensured that water and oxygen cannot invade the organic light-emitting layer 7 and the cathode 8 in the sub-pixel, thereby ensuring the normal display of the display product.

[0068] The light emitting device may include a red (R) light emitting device that emits red light, a green (G) light emitting device that emits green light, and a blue (B) light emitting device that emits blue light. The light emitting device may be an inorganic light emitting diode, an organic light emitting diode (OLED) made of organic materials, a micro light emitting diode (Micro LED), or a mini light emitting diode (mini LED). A micro light emitting diode refers to an ultra-small inorganic light emitting element with a size of less than 100 microns that emits light without a backlight or a filter.

[0069] The pixel circuit can adopt a variety of structures, for example, the pixel circuit can include a structure of 2 transistors and 1 capacitor (2T1C), or a structure of 7 transistors and 1 capacitor (7T1C), or a structure of 12 transistors and 1 capacitor (12T1C). The pixel circuit generally includes a driving transistor and the remaining switching transistors, such as Figure 3 and Figure 4 As shown, a schematic diagram of a driving transistor, a light-emitting device and a storage capacitor in a pixel circuit is illustrated. The driving transistor may be a top-gate type, including an active layer 21, a first gate insulating layer 22, a gate electrode 23, a second gate insulating layer 24, an interlayer dielectric layer 25, a source electrode 26 and a drain electrode 27 stacked on a substrate 1. Specifically, the active layer 21 may be formed on a buffer layer 28, the buffer layer 28 is disposed on a first barrier layer 29, the first gate insulating layer 22 covers the buffer layer 28 and the active layer 21, the gate electrode 23 is formed on a side of the first gate insulating layer 22 away from the active layer 21, the second gate insulating layer 24 covers the gate electrode 23 and the first gate insulating layer 22, the interlayer dielectric layer 25 covers the second gate insulating layer 24, the source electrode 26 and the drain electrode 27 are formed on a side of the interlayer dielectric layer 25 away from the substrate 1 and are respectively located on opposite sides of the gate electrode 23, and the source electrode 26 and the drain electrode 27 may respectively contact opposite sides of the active layer 21 through vias. As shown Figure 3 and Figure 4As shown, the capacitor structure (for example, the storage capacitor Cst in the pixel circuit) may include a first electrode plate C1 and a second electrode plate C2, wherein the second electrode plate C2 is arranged in the same layer as the gate electrode 23, the first electrode plate C1 is located between the second gate insulating layer 24 and the interlayer dielectric layer 25, and the first electrode plate C1 is arranged opposite to the second electrode plate C2.

[0070] Specifically, Figure 3 and Figure 4 As shown, the signal line 2 located in the connection bridge area Q3 is arranged in the film layer where the source 26 and the drain 27 are located. The anode 6 and the drain 27 of the light-emitting device can be directly electrically connected (i.e., a single-layer SD structure), or can be electrically connected through a lap electrode 30 located therebetween (i.e., a double-layer SD structure), a first flat layer 31 is arranged between the lap electrode 30 and the drain 27, a second flat layer 32, a first passivation layer 33, and a second passivation layer 34 are arranged between the lap electrode 30 and the anode 6, and each light-emitting device in the stretchable display substrate is generally defined by a pixel defining layer 35, and the pixel defining layer 35 has an opening area for exposing the light-emitting device.

[0071] In the stretchable display substrate provided in the embodiment of the present disclosure, the base may include a flexible layer, or Figure 3 and Figure 4 As shown, the substrate 1 includes a first flexible layer 11 , a second barrier layer 12 , and a second flexible layer 13 which are stacked and arranged on a side of the first barrier layer 29 away from the buffer layer 28 .

[0072] Specifically, the material of the flexible layer may be polyimide (PI), polyester, polyamide, or the like.

[0073] Specifically, Figure 3 and Figure 4 As shown, the base 1 can be disposed on a glass substrate 10 to facilitate subsequent peeling.

[0074] Specifically, Figure 3 and Figure 4 As shown, the distance between the side wall of the first hollow portion 3 close to the pixel unit 4 and the partition structure 9 (i.e., the width of the inorganic insulating layer between the first hollow portion 3 and the partition structure 9) can be greater than or equal to 2um, the organic light-emitting layer 7 is disconnected at the partition structure 9, and the cathode 8 is disconnected at the partition structure 9.

[0075] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 1 As shown, the first hollow portion 3 is a closed structure arranged around the hole area Q2, so that the inorganic insulating layer of the connecting bridge area Q3 can be removed as much as possible, thereby maximizing the tensile performance of the connecting bridge area.

[0076] In a specific implementation, since water and oxygen easily invade into the pixel unit from the hole area, in order to block the water and oxygen invasion paths at various positions of the hole area, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 As shown, the partition structure 9 is a closed structure arranged around the first hollow portion 3, that is, the orthographic projection pattern of the partition structure 9 on the substrate 1 is the same as the boundary pattern of the hole area Q2, that is, the partition structure 9 is arranged around the hole area Q2, thereby ensuring that the partition structure 9 prevents water and oxygen from invading the pixel island area Q1 from the hole area Q2 at various positions.

[0077] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 2 As shown, a portion of the hole area Q2 includes: a first sub-hole area Q21 and a second sub-hole area Q22 extending along the first direction X and arranged along the second direction Y, and a third sub-hole area Q23 extending along the second direction Y; another portion of the hole area Q2 includes: a fourth sub-hole area Q24 and a fifth sub-hole area (not shown) extending along the second direction Y and arranged along the first direction X, and a sixth sub-hole area Q26 extending along the first direction X; the first direction X and the second direction Y are substantially perpendicular, and the sixth sub-hole area Q26 substantially connects the central areas of the fourth sub-hole area Q24 and the fifth sub-hole area;

[0078] When the stretchable display substrate is stretched, Figure 2 As shown in the figure, one side (corner) of the connection position between the first sub-hole area Q21 and the third sub-hole area Q23, one side (corner) of the connection position between the second sub-hole area Q22 and the third sub-hole area Q23, one side of the end of the first sub-hole area Q21 and one side of the end of the second sub-hole area Q22, one side (corner) of the connection position between the fourth sub-hole area Q24 and the sixth sub-hole area Q26, one side of the connection position between the fifth sub-hole area and the sixth sub-hole area Q26, one side of the end of the fourth sub-hole area Q24 and one side of the end of the fifth sub-hole area are all stress concentration points generated during stretching, and the inorganic insulating layer at these positions is broken first. In order to avoid the inorganic insulating layer from breaking at these positions, the present disclosure sets the first hollow portion 3 at least at one of the following positions: one side of the connection position between the first sub-hole area Q21 and the third sub-hole area Q23, one side of the connection position between the second sub-hole area Q22 and the third sub-hole area Q23, one side of the end of the first sub-hole area Q21 and one side of the end of the second sub-hole area Q22, one side of the connection position between the fourth sub-hole area Q24 and the sixth sub-hole area Q26, one side of the connection position between the fifth sub-hole area and the sixth sub-hole area Q26, one side of the end of the fourth sub-hole area Q24 and one side of the end of the fifth sub-hole area. In this way, the difficulty of making a large-area first hollow portion 3 can be reduced, and the problem of inorganic insulating layer breaking at the inorganic insulating layer easy-to-break position corresponding to the hole area Q2 can be avoided.

[0079] It should be noted that if Figure 1 and Figure 2As shown, the embodiment of the present disclosure is illustrated by taking the shape of the hole area Q2 as approximately an "I" shape as an example. Of course, the shape of the hole area Q2 is not limited to this, for example, it can also be a "T" shape, an "I" shape, etc.

[0080] Preferably, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 2 As shown, the first hollow portion 3 is provided on one side of the connection position between the first sub-hole area Q21 and the third sub-hole area Q23, on one side of the connection position between the second sub-hole area Q22 and the third sub-hole area Q23, on one side of the end of the first sub-hole area Q21 and on one side of the end of the second sub-hole area Q22, on one side of the connection position between the fourth sub-hole area Q24 and the sixth sub-hole area Q26, on one side of the connection position between the fifth sub-hole area and the sixth sub-hole area Q26, on one side of the end of the fourth sub-hole area Q24 and on one side of the end of the fifth sub-hole area.

[0081] In the stretchable display substrate provided in the embodiment of the present disclosure, Figure 1 and Figure 2 As shown, the pixel island region Q1 includes at least one pixel unit 4, and the pixel resolution of the pixel island region Q1 is substantially the same as the pixel resolution of the connecting bridge region Q3, which can improve the display resolution and improve the problem of uneven display.

[0082] In the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 and Figure 4 As shown, the multiple inorganic insulating layers include a first barrier layer 29, a buffer layer 28, a first gate insulating layer 22, a second gate insulating layer 24, an interlayer dielectric layer 25, a first passivation layer 33, a second passivation layer 34 and an inorganic encapsulation layer 36 stacked on a substrate 1, and at least one of the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22, the second gate insulating layer 24, the interlayer dielectric layer 25, the first passivation layer 33, the second passivation layer 34 and the inorganic encapsulation layer 36 is provided with a first hollow portion 3.

[0083] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 and Figure 4 As shown, the interlayer dielectric layer 25, the first passivation layer 33, the second passivation layer 34 and the inorganic encapsulation layer 36 are all provided with first hollow portions 3, and the first hollow portions 3 are substantially overlapped. Of course, in a specific implementation, the first hollow portions 3 can also be provided in the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22 and the second gate insulating layer 24.

[0084] It should be noted that if Figure 3 and Figure 4As shown, the embodiment of the present disclosure is schematically described by providing the first hollowing portion 3 in the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22, the second gate insulating layer 24, the interlayer dielectric layer 25, the first passivation layer 33, the second passivation layer 34 and the inorganic encapsulation layer 36. Of course, the first hollowing portion 3 is provided in multiple inorganic insulating layers (i.e., each inorganic insulating layer is etched to hollow out the inorganic insulating layer in the corresponding area), and the hollowing process of multiple inorganic insulating layers can be hollowing out from the uppermost inorganic encapsulation layer 36 to any inorganic insulating layer above the second flexible layer 13, for example, directly hollowing out to the second flexible layer 13, or directly hollowing out to any one of the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22, the second gate insulating layer 24, the interlayer dielectric layer 25, the first passivation layer 33, the second passivation layer 34 and the inorganic encapsulation layer 36 film layers. The hollowing out of the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22, the second gate insulating layer 24, and the interlayer dielectric layer 25 can be achieved through one or two etching processes in the process of preparing the stretchable display substrate, and the hollowing out of the inorganic encapsulation layer 36 is achieved by etching thinning through a single exposure and etching process after the inorganic encapsulation layer 36 is made. Of course, the hollowing out of all inorganic insulating layers can also be achieved through a single exposure and deep hole etching process after all inorganic insulating layers are made; the specific etching process can be selected according to actual needs.

[0085] In a specific implementation, in the stretchable display substrate provided in the embodiment of the present disclosure, Figure 3 and Figure 4 As shown, the inorganic encapsulation layer 36 includes a first inorganic layer and a second inorganic layer stacked on the second passivation layer 34;

[0086] The stretchable display substrate further includes: a first planar layer 31 and a second planar layer 32 located between the interlayer dielectric layer 25 and the first passivation layer 33, a pixel defining layer 35 located between the second passivation layer 34 and the inorganic encapsulation layer 36, and an organic layer located between the first inorganic layer and the second inorganic layer;

[0087] At least one of the first planar layer 31 , the second planar layer 32 , the pixel defining layer 35 and the organic layer has a second hollow portion near the hole region Q2 , and the first hollow portion 3 and the second hollow portion substantially overlap.

[0088] It should be understood that the first barrier layer 29, the buffer layer 28, the first gate insulating layer 22, the second gate insulating layer 24, the interlayer dielectric layer 25, the first passivation layer 33, the second passivation layer 34 and the inorganic encapsulation layer 36 mentioned in the embodiment of the present disclosure can be made of inorganic insulating materials such as silicon oxide and silicon nitride. The first flat layer 31, the second flat layer 32, the pixel defining layer 35 and the organic layer can be organic film layers, that is, they can be made of organic insulating materials such as photoresist and PI.

[0089] It should be noted that when all the inorganic insulating layers on the substrate 1 are etched away in the connecting bridge area Q3, the first flat layer 31, the second flat layer 32, the pixel defining layer 35 and the organic layer will also be etched away, that is, a via hole penetrating all the inorganic insulating layers and the organic insulating layers is formed in the connecting bridge area Q3, which can be represented by the first hollow portion 3.

[0090] The inventor of this case provides the embodiment of the present disclosure Figure 3 The stretchable display substrate shown was tested for stretchable performance with the stretchable display substrate in the related art that did not have a first hollow portion in the connecting bridge area. The test found that the stretching amount of the present disclosure was approximately 2%, while the stretching amount in the related art was less than 1%. Therefore, the stretchable display substrate provided by the embodiment of the present disclosure significantly improves the stretching performance.

[0091] Based on the same inventive concept, the present disclosure also provides a method for preparing the above-mentioned stretchable display substrate, such as Figure 5 As shown, including:

[0092] S501, providing a substrate;

[0093] S502, forming a pixel unit and a signal line electrically connected to the pixel unit on a substrate;

[0094] S503, forming a plurality of inorganic insulating layers stacked on the substrate; wherein at least one of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and the orthographic projection of the first hollow portion on the substrate does not overlap with the orthographic projection of the signal line and the pixel unit on the substrate.

[0095] In the specific implementation, in the above-mentioned preparation method provided by the embodiment of the present disclosure, at least one layer of the plurality of inorganic insulating layers has a first hollow portion near the hole region, such as Figure 6 As shown, specifically including:

[0096] S601, depositing a first barrier layer, a buffer layer, a first gate insulating layer, a second gate insulating layer, an interlayer dielectric layer, a first passivation layer, a second passivation layer and an inorganic encapsulation layer on the substrate;

[0097] S602 , using a patterning process to form a first hollow portion in at least one of the first barrier layer, the buffer layer, the first gate insulating layer, the second gate insulating layer, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer.

[0098] The process of forming each layer structure in the embodiment of the present disclosure may include a composition process and a photolithography process, wherein the composition process may include depositing a film layer, coating a photoresist, mask exposure, development, etching, stripping the photoresist and other processes, and the photolithography process may include coating a film layer, mask exposure, development and other processes, and the evaporation, deposition, coating, and coating used are all mature preparation processes in the relevant technology.

[0099] The following details Figure 3 The preparation process of the stretchable display substrate shown may include the following steps:

[0100] (1) Taking the substrate 1 including two flexible layers as an example, the substrate 1 is divided into a pixel island region Q1, a hole region Q2 and a connecting bridge region Q3, and a first flexible layer 11, a second barrier layer 12 and a second flexible layer 13 are sequentially stacked on a glass substrate 10; when forming the second barrier layer 12, the second barrier layer 12 corresponding to the hole region Q2 is etched away; then, a first barrier layer 29 is formed on the second flexible layer 13; Fig. 7A As shown. The material of the flexible layer can be polyimide (PI), polyester, polyamide, etc. The material of the barrier layer can be silicon nitride (SiNx) or silicon oxide (SiOx), etc., to improve the water and oxygen resistance of the substrate.

[0101] (2) forming a buffer layer 28 on the first barrier layer 29, depositing an active layer thin film on the buffer layer 28, patterning the active layer thin film through a patterning process, forming an active layer 21 on the buffer layer 28, and forming a first gate insulating layer 22 on the active layer 21, as shown in FIG. Figure 7B shown.

[0102] (3) A metal film is deposited on the first gate insulating layer 22, and the metal film is patterned by a patterning process to form a gate 23, a second electrode plate C2 and a gate line (not shown) on the first insulating layer 22, and a gate connection line (not shown) formed in the connecting bridge region Q3. Subsequently, a second gate insulating layer 24 is formed on the gate 23. Figure 7C shown.

[0103] (4) a metal film is deposited on the second gate insulating layer 24, and the metal film is patterned by a patterning process to form a first electrode C1 on the second insulating layer 24, and the position of the first electrode C1 corresponds to the position of the second electrode C2; ​​then, an interlayer dielectric layer 25 is formed on the film layer where the first electrode C1 is located, and the first gate insulating layer 22, the second gate insulating layer 24 and the interlayer dielectric layer 25 are patterned to form via holes located above the two ends of the active layer 21, via holes corresponding to the hole area Q2, and a first hollow portion 3 located corresponding to the connecting bridge area Q3, as shown in FIG. Fig.7D shown.

[0104] (5) A metal film (SD1 layer) is deposited on the interlayer dielectric layer 25, and the metal film is patterned by a patterning process to form a source electrode 26, a drain electrode 27 and a signal line 2 (data line) on the interlayer dielectric layer 25. The source electrode 26 and the drain electrode 27 are connected to the active layer 21 through via holes penetrating the first gate insulating layer 22, the second gate insulating layer 24 and the interlayer dielectric layer 25, respectively. Next, a flat film of organic material is coated on the substrate 1 on which the source electrode 26 and the drain electrode 27 are formed, and a first flat layer 31 is formed by masking, exposure and development processes. The first flat layer 31 corresponding to the position of the source electrode 26, the position of the hole area Q2 and the position of the first hollow portion 3 of the connecting bridge area Q3 are all developed away, as shown in FIG. Fig. 7E shown.

[0105] (6) A metal film (SD2 layer, or no SD2 layer) is deposited on the first flat layer 31, and the metal film is patterned by a patterning process to form a bonding electrode 30 on the first flat layer 31; a flat film coated with an organic material is formed on the film layer where the bonding electrode 30 is located, and a second flat layer 32 is formed by a mask, exposure, and development process, and the second flat layer 32 corresponding to the bonding electrode 30 position, the hole area Q2 position, and the first hollow portion 3 position are all developed; then, an inorganic insulating material is deposited on the second flat layer 32, and then, first, the buffer layer 28 and the first barrier layer 29 of the hole area Q2 are etched away, and the first flexible layer 11 and the second flexible layer 13 of the hole area Q2 are etched away; the inorganic insulating material, the buffer layer 28 and the first barrier layer 29 at the position corresponding to the first hollow portion 3 are etched away, and the inorganic insulating material, the second flat layer 32 and a part of the first flat layer 31 at the position corresponding to the partition structure 9 of the connecting bridge area Q3 are etched away, and the inorganic insulating material after etching forms a first passivation layer 33, as shown in FIG. Figure 7F shown.

[0106] (7) Depositing an inorganic insulating material on the first passivation layer 33, etching away the inorganic insulating material at the hole region Q2 and the first hollow portion 3, and etching away the inorganic insulating material and the first passivation layer 33 at the corresponding position of the bonding electrode 30, to form a second passivation layer 34, such as Figure 7G shown.

[0107] (8) A conductive film is deposited on the second passivation layer 34, and the conductive film is patterned by a patterning process to form an anode 6. The anode 6 is electrically connected to the bonding electrode 30 through a via hole penetrating the first passivation layer 33 and the second passivation layer 34, such as Figure 7H In an exemplary embodiment, the conductive film may be a three-layer stacked structure of a transparent conductive film / metal film / transparent conductive film, wherein the transparent conductive film may be made of indium tin oxide ITO or indium zinc oxide IZO, and the metal film may be a metal film such as Al, Ag, or Cu.

[0108] (9) A pixel definition film is coated on the anode 6, and a pixel definition layer 35 is formed by masking, exposure, and development processes. A pixel opening is provided on the pixel definition layer 35 of the pixel island region Q1, and the pixel definition layer 35 in the pixel opening is developed away to expose the surface of the anode 6; and the pixel definition layer 35 corresponding to the position of the hole region Q2 and the position of the connecting bridge region Q3 are all developed away, such as Fig.7I shown.

[0109] (10) An organic light-emitting layer 7 and a cathode 8 are sequentially formed on the pixel defining layer 35. The organic light-emitting layer 7 is formed in a pixel opening of the pixel defining layer 35 and connected to the anode 6. The organic light-emitting layer 7 and the cathode 8 are disconnected at the position of the partition structure 9, respectively. Figure 7J Specifically, the organic light emitting layer 6 and the cathode 7 can be both formed by evaporation process. The material of the cathode 8 can be any one or more of magnesium (Mg), silver (Ag), aluminum (Al), copper (Cu) and lithium (Li), or an alloy made of any one or more of the above metals.

[0110] (11) An inorganic encapsulation layer 36 is formed on the cathode 8. The inorganic encapsulation layer 36 may include a first inorganic layer, an organic layer, and a second inorganic layer that are stacked. The inorganic encapsulation layer 36, the cathode 8, and the organic light-emitting layer 6 corresponding to the position of the hole region Q2 and the position of the first hollow portion 3 are etched away. Figure 7K As shown, the embodiment of the present disclosure provides Figure 3 The stretchable display substrate shown.

[0111] It should be noted that the embodiments of the present disclosure are based on Figure 3 The preparation method of the stretchable display substrate shown in FIG. Figure 4 The preparation method of the stretchable display substrate shown in Figure 3 The preparation method is similar to that shown in Figure 3 All inorganic insulating layers and organic insulating layers between the first hollow portion 3 and the hole region Q2 are etched away to form a structure in which the first hollow portion 3 and the hole region Q2 are connected. Figure 4 The preparation method shown is not described in detail. The etching of the inorganic insulating layer and the organic insulating layer between the first hollow portion 3 and the hole area Q2 is the same as that of other areas, and the film layers can be etched together.

[0112] Finally, Figure 3 and Figure 4 The stretchable display substrate can be manufactured by peeling off the glass substrate 10 below the stretchable display substrate.

[0113] Based on the same inventive concept, the embodiment of the present disclosure also provides a display device, including any of the above-mentioned stretchable display substrates provided in the embodiment of the present disclosure. The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc. The implementation of the display device can refer to the above-mentioned embodiment of the stretchable display substrate, and the repeated parts will not be repeated.

[0114] The above-mentioned display device can be any product or component with display function, such as an organic light emitting diode display panel, a quantum dot light emitting diode display panel, a display module, a curved screen mobile phone, a smart watch, etc.

[0115] The embodiments of the present disclosure provide a stretchable display substrate, a preparation method thereof, and a display device. When the stretchable display substrate is stretched, a connecting bridge area adjacent to the hole area is subjected to tensile force and deforms. The present disclosure arranges at least one of the multiple inorganic insulating layers to have a first hollow portion in the connecting bridge area near the hole area, that is, at least one of the multiple inorganic insulating layers is removed at a position near the hole area in the connecting bridge area. In this way, the buckling deformation behavior of the connecting bridge area when stretched can be improved, so that the connecting bridge area is not prone to breakage and the pixel island area adjacent to the connecting bridge area is not easily damaged, thereby improving the stretching performance of the stretchable display substrate.

[0116] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these modifications and variations.

Claims

1. A stretchable display substrate, wherein: Comprising a plurality of hole regions; the stretchable display substrate comprises: substrate; A pixel unit is arranged on the substrate; A signal line, disposed on the substrate and electrically connected to the pixel unit; A plurality of inorganic insulating layers are stacked on the substrate, at least one of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and an orthographic projection of the first hollow portion on the substrate does not overlap with an orthographic projection of the signal line and the pixel unit on the substrate; The stretchable display substrate further comprises: a plurality of pixel island regions spaced apart between the hole regions, and a connecting bridge region between the pixel island regions and the hole regions; The first hollow portion is not connected to the hole area.

2. The stretchable display substrate according to claim 1, wherein: The connecting bridge area includes at least one pixel unit, the first hollow portion is located in the connecting bridge area, and the first hollow portion is located between the pixel unit in the connecting bridge area and the hole area.

3. The stretchable display substrate according to claim 2, wherein: The connecting bridge area includes a plurality of the pixel units, and the orthographic projection of the signal line on the substrate is at least located within the orthographic projection of the pixel units in the connecting bridge area and the area between the pixel units in the connecting bridge area on the substrate.

4. The stretchable display substrate according to claim 1, wherein: The extension direction of the first hollow portion is substantially the same as the edge of the hole area.

5. The stretchable display substrate according to claim 1, wherein: A distance between a side wall of the first hollow portion close to the hole region and a side wall of the hole region close to the first hollow portion is greater than or equal to 2 μm.

6. The stretchable display substrate according to claim 1, wherein: Along the direction from the pixel island area to the hole area, the width of the first hollow portion is greater than or equal to 5um.

7. The stretchable display substrate according to claim 1, wherein: The pixel unit includes at least one sub-pixel, the sub-pixel includes a pixel circuit and a light-emitting device, the light-emitting device includes a stacked anode, an organic light-emitting layer and a cathode; a partition structure is provided in the connection bridge area near the pixel unit, the organic light-emitting layer is disconnected at the partition structure, and the cathode is disconnected at the partition structure; The distance between the side wall of the first hollow portion close to the pixel unit and the partition structure is greater than or equal to 2 um.

8. The stretchable display substrate according to any one of claims 1, 6 and 7, wherein: The first hollow portion is a closed structure arranged around the hole area.

9. The stretchable display substrate according to claim 8, wherein: A partition structure is arranged in the connection bridge area near the pixel unit, and the partition structure is a closed structure arranged around the first hollow portion.

10. The stretchable display substrate according to claim 1, wherein: A portion of the hole area includes: a first sub-hole area and a second sub-hole area extending along the first direction and arranged along the second direction, and a third sub-hole area extending along the second direction; another portion of the hole area includes: a fourth sub-hole area and a fifth sub-hole area extending along the second direction and arranged along the first direction, and a sixth sub-hole area extending along the first direction; the first direction and the second direction are substantially perpendicular, the third sub-hole area substantially connects the central areas of the first sub-hole area and the second sub-hole area, and the sixth sub-hole area substantially connects the central areas of the fourth sub-hole area and the fifth sub-hole area; The first hollow portion is at least arranged at at least one of the following positions: one side of the connection position between the first sub-hole area and the third sub-hole area, one side of the connection position between the second sub-hole area and the third sub-hole area, one side of the end of the first sub-hole area and one side of the end of the second sub-hole area, one side of the connection position between the fourth sub-hole area and the sixth sub-hole area, one side of the connection position between the fifth sub-hole area and the sixth sub-hole area, one side of the end of the fourth sub-hole area and one side of the end of the fifth sub-hole area.

11. The stretchable display substrate according to claim 10, wherein: The first hollow portion is provided on one side of the connection position between the first sub-hole area and the third sub-hole area, one side of the connection position between the second sub-hole area and the third sub-hole area, one side of the end of the first sub-hole area and one side of the end of the second sub-hole area, one side of the connection position between the fourth sub-hole area and the sixth sub-hole area, one side of the connection position between the fifth sub-hole area and the sixth sub-hole area, one side of the end of the fourth sub-hole area and one side of the end of the fifth sub-hole area.

12. The stretchable display substrate according to claim 1, wherein: The pixel island region includes at least one pixel unit, and a pixel resolution of the pixel island region is substantially the same as a pixel resolution of the connecting bridge region.

13. The stretchable display substrate according to claim 1, wherein: The multiple inorganic insulating layers include a first barrier layer, a buffer layer, a first gate insulating layer, a second gate insulating layer, an interlayer dielectric layer, a first passivation layer, a second passivation layer and an inorganic encapsulation layer stacked on the substrate, and the first hollow portion is set in at least one of the first barrier layer, the buffer layer, the first gate insulating layer, the second gate insulating layer, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer.

14. The stretchable display substrate according to claim 13, wherein: The interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer are all provided with the first hollow portions, and the first hollow portions are substantially overlapped.

15. The stretchable display substrate according to claim 13, wherein: The inorganic encapsulation layer includes a first inorganic layer and a second inorganic layer stacked on the second passivation layer; The stretchable display substrate further includes: a first planar layer and a second planar layer located between the interlayer dielectric layer and the first passivation layer, a pixel defining layer located between the second passivation layer and the inorganic encapsulation layer, and an organic layer located between the first inorganic layer and the second inorganic layer; At least one of the first planar layer, the second planar layer, the pixel defining layer and the organic layer has a second hollow portion near the hole region, and the first hollow portion and the second hollow portion substantially overlap.

16. The stretchable display substrate according to claim 13, wherein: The substrate includes a flexible layer, or the substrate includes a first flexible layer, a second barrier layer, and a second flexible layer which are stacked and arranged on a side of the first barrier layer away from the buffer layer.

17. A display device, wherein: Comprising a stretchable display substrate according to any one of claims 1-16.

18. A method for preparing a stretchable display substrate according to any one of claims 1 to 16, wherein: include: providing a substrate; forming a pixel unit and a signal line electrically connected to the pixel unit on the substrate; A plurality of inorganic insulating layers are stacked on the substrate; wherein at least one of the plurality of inorganic insulating layers has a first hollow portion near the hole area, and the orthographic projection of the first hollow portion on the substrate does not overlap with the orthographic projection of the signal line and the pixel unit on the substrate.

19. The preparation method according to claim 18, wherein: At least one of the plurality of inorganic insulating layers has a first hollow portion near the hole region, specifically comprising: Depositing a first barrier layer, a buffer layer, a first gate insulating layer, a second gate insulating layer, an interlayer dielectric layer, a first passivation layer, a second passivation layer and an inorganic encapsulation layer on the substrate; The first hollow portion is formed in at least one of the first barrier layer, the buffer layer, the first gate insulating layer, the second gate insulating layer, the interlayer dielectric layer, the first passivation layer, the second passivation layer and the inorganic encapsulation layer by using a patterning process.

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