Display device and manufacturing method thereof, and electronic equipment

Abstract

The present application discloses a display device and a preparation method thereof, and an electronic device, wherein the protective film of the display device includes a thinned area, and the orthographic projection of the thinned area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate, so that in the process of AOI (Automated Optical Inspection) detecting the binding effect of the binding structure, the absorption of light by the protective film in the thinned area is reduced, and the amount of light entering the photosensitive element is increased, thereby improving the clarity of the image obtained by the photosensitive element, meeting the imaging requirements of AOI detection, and meeting the requirements for accurate detection of the binding effect of the binding structure.

Description

Technical Field

[0001] The present application relates to the field of display technology, and more specifically, to a display device and a method for preparing the same, and an electronic device. Background Art

[0002] In the preparation process of flexible display devices such as OLED (Organic Light-Emitting Diode) display devices or Micro-LED display devices, after the binding structure is bound to the substrate through the binding process, it is necessary to use AOI (Automated Optical Inspection) technology to perform indentation detection to detect the binding effect of the binding structure.

[0003] How to improve the accuracy of AOI detection has become an urgent problem to be solved. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a display device and a manufacturing method thereof, and an electronic device, so as to improve the detection accuracy when performing AOI detection on the display device.

[0005] To achieve the above technical objectives, the present application provides the following technical solutions:

[0006] A display device, comprising:

[0007] a substrate, the substrate comprising a step region;

[0008] a binding structure located on one side of the step area;

[0009] A protective film is located on a side of the step region away from the binding structure, wherein the protective film comprises a thinned region, and an orthographic projection of the thinned region on the substrate at least partially overlaps with an orthographic projection of the binding structure on the substrate.

[0010] A method for preparing a display device, comprising:

[0011] providing a substrate, the substrate comprising a step region;

[0012] forming a binding structure on one side of the step area;

[0013] forming a protective film on a side of the step area away from the binding structure;

[0014] The protective film is processed to form a thinned region in the protective film, wherein an orthographic projection of the thinned region on the substrate at least partially overlaps with an orthographic projection of the binding structure on the substrate.

[0015] An electronic device comprises the display device as described in any one of the above items.

[0016] It can be seen from the above technical scheme that the embodiments of the present application provide a display device and a preparation method thereof, and an electronic device, wherein the protective film of the display device includes a thinned area, and the orthographic projection of the thinned area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate. In this way, during the AOI detection of the binding effect of the binding structure, the absorption of light by the protective film in the thinned area is reduced, and the amount of light entering the photosensitive element is increased, thereby improving the clarity of the image acquired by the photosensitive element, satisfying the imaging requirements of the AOI detection, and satisfying the requirements for accurate detection of the binding effect of the binding structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0018] Figure 1 It is a grayscale image obtained by the photosensitive element when the conductive particles are normally compressed;

[0019] Figure 2 It is a grayscale image obtained by the photosensitive element when the conductive particles are under-compressed;

[0020] Figure 3 It is a grayscale image obtained by the photosensitive element when the conductive particles are over-stressed;

[0021] Figure 4 A schematic diagram of a cross-sectional structure of a display device provided in an embodiment of the present application along a direction perpendicular to a substrate surface;

[0022] Figure 5 A schematic diagram of a cross-sectional structure of a display device along a direction perpendicular to a substrate surface provided in another embodiment of the present application;

[0023] Figure 6 A schematic diagram of a local cross-section of a step region along a direction perpendicular to a substrate provided for one embodiment of the present application;

[0024] Figure 7 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided in another embodiment of the present application;

[0025] Figure 8 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided in yet another embodiment of the present application;

[0026] Fig. 9 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided in yet another embodiment of the present application;

[0027] Fig.10 A schematic diagram of a local cross-section of a step region along a direction perpendicular to a substrate provided for an optional embodiment of the present application;

[0028] Fig.11 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided for another optional embodiment of the present application;

[0029] Fig.12 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided in yet another optional embodiment of the present application;

[0030] Fig.13 A schematic diagram of a local cross-section of a step region along a direction perpendicular to the substrate provided in yet another optional embodiment of the present application;

[0031] Fig.14 A schematic flow chart of a method for preparing a display device provided in one embodiment of the present application;

[0032] Figure 15-17 A schematic diagram of a manufacturing process of a display device provided in accordance with an embodiment of the present application;

[0033] Fig.18 A schematic flow chart of a method for preparing a display device provided in another embodiment of the present application;

[0034] Fig.19 A schematic diagram of the structure of an electronic device provided for one embodiment of the present application. DETAILED DESCRIPTION

[0035] As described in the background technology, how to improve the accuracy of AOI detection is a technical problem that needs to be solved urgently by those skilled in the art. The inventors found in the actual detection process that due to the poor light transmittance of the substrate itself and the protective film on the back of the substrate, it is difficult for the photosensitive element to obtain a clear binding effect image during the AOI detection process, and it is impossible to accurately detect the binding effect of the binding structure. Specifically, in the prior art, when using AOI technology to detect the binding effect of the binding structure, due to the low transmittance of the substrate and the protective film, the amount of light that enters the photosensitive element through the substrate and the protective film is small, resulting in poor detection effect.

[0036] After research, the inventors found that the detection principle of the binding effect of the binding structure by AOI technology includes: the photosensitive element is set on the side of the substrate away from the binding structure to image the area where the binding structure is located, and the light passes through the conductive film between the binding structure and the substrate, the substrate, and the protective film on the back of the substrate to enter the photosensitive element in sequence, so that the photosensitive element performs grayscale imaging according to the light intensity received by different photosensitive areas. If the conductive particles in the conductive film are normally compressed during the binding process, the area where the conductive particles are located will be clearly displayed in the grayscale image (such as Figure 1 As shown, Figure 1 The grayscale image is obtained by the photosensitive element when the conductive particles are under normal pressure). However, if the conductive particles are under-pressed or over-pressed and crushed, their location will not be obvious in the grayscale image and it will be difficult to distinguish them from other background areas (refer to Figure 2 and Figure 3 , Figure 2 and Figure 3 The grayscale images are obtained by the photosensitive element when the conductive particles are under-pressed and over-pressed respectively).

[0037] However, after further research, the inventors found that due to the low light transmittance of the substrate itself and the low light transmittance of the protective film on the back of the substrate, the amount of light that can penetrate the substrate and the protective film is very small, resulting in a very small amount of light actually received by the photosensitive element. The grayscale difference between each area in the final grayscale image is very small, so even if the conductive particles are compressed normally, no obvious brightness difference can be observed in the grayscale image. This means that during the AOI inspection process, regardless of whether the conductive particles are compressed normally, it is impossible to observe the location of the conductive particles from the grayscale image finally obtained by the photosensitive element, resulting in the AOI inspection losing its practical significance and being unable to accurately detect the binding effect of the binding structure.

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] The present application embodiment provides a display device, such as Figure 4 As shown, Figure 4 is a schematic diagram of a cross-sectional structure of the display device along a direction perpendicular to the substrate surface, wherein the display device comprises:

[0040] The substrate 40 includes a step region BB. Figure 4 The step area BB of the substrate 40 refers to other areas except the display area AA for setting display pixels. Figure 4In the embodiment, the step area BB also includes a bending area bending, and most of the step area BB can be bent to the back side of the display area of ​​the substrate 40 through bending of the bending area bending, thereby achieving "hiding" of the step area BB and improving the screen-to-body ratio of the display device.

[0041] The binding structure 20 is located on one side of the step area BB. The binding method of the binding structure 20 and the substrate 40 includes but is not limited to COF (Chip on Film) and COP (Chip on Panel).

[0042] The protective film 10 located on the side of the step area BB away from the binding structure 20 includes a thinned area 11, and the orthographic projection of the thinned area 11 on the substrate 40 at least partially overlaps with the orthographic projection of the binding structure 20 on the substrate 40. The thinned area 11 of the protective film 10 may be an area including structures such as grooves or through holes, and the thinning process for the protective film 10 may include a laser removal process. Compared with the protective film 10 of normal thickness, the protective film 10 in the thinned area 11 absorbs less light, which is beneficial to increase the amount of light that finally enters the photosensitive element 30 (such as CCD (Charge-coupled Device)) used for AOI detection, thereby improving the clarity of the image acquired by the photosensitive element 30, meeting the imaging requirements of AOI detection, and meeting the requirements for accurate detection of the binding effect of the binding structure 20.

[0043] The orthographic projection of the thinned region 11 on the substrate 40 and the orthographic projection of the binding structure 20 on the substrate 40 at least partially overlap, which can be as follows Figure 4 The parts shown overlap, or they can be Figure 5 All the overlaps shown, Figure 5 The cross-sectional structure diagram of the display device along the direction perpendicular to the substrate surface. When the orthographic projection of the thinned area 11 on the substrate 40 partially overlaps with the orthographic projection of the binding structure 20 on the substrate 40, the orthographic projection of the photosensitive area of ​​the photosensitive element 30 used for AOI inspection on the substrate 40 should be located in the partially overlapping area, so as to take advantage of the small amount of light absorption by the thinned area 11 to inspect the binding structure 20.

[0044] In order to more clearly illustrate the structure of the step area BB, only part of the display area is shown in the drawings provided in the embodiments of the present application, and in order to clearly indicate the feasible arrangement position of the photosensitive element 30, Figure 4 and Figure 5 The photosensitive element 30 used for AOI detection is also shown in FIG. Figure 4 and 5Also shown are the driving film layer 90, polarizer 60 and protective cover 70 located in the display area AA, and the adhesive layer 80 for fixing or encapsulating the polarizer 60, protective cover 70 and binding structure 20. The driving film layer 90 includes at least a plurality of pixel circuits composed of a thin film transistor array. In some embodiments, the driving film layer 90 also includes a plurality of light-emitting units, including but not limited to OLED light-emitting units and Micro-LED light-emitting units, and the anode of the light-emitting unit is electrically connected to the pixel circuit. In addition Figure 4 and Figure 5 Also shown is an interconnection line 100 electrically connected to the pixel circuit, and the interconnection line 100 includes but is not limited to a data fan-out line, a gate fan-out line, a power fan-out line, and the like.

[0045] In some embodiments of the present application, reference is still made to Figure 4 and Figure 5 The binding structure 20 may specifically include a first conductive pad 26, conductive particles 23, and a second conductive substrate 24, and the carrier of the conductive particles 23 may include an anisotropic conductive film 25. The first conductive pad 26 is electrically connected to the interconnection trace 100 on the substrate, so that the first conductive pad 26 is electrically connected to the pixel circuit of the driving film layer 90. The first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 25. The second conductive pad 26 is electrically connected to the functional circuit on the chip or FPC.

[0046] The functional circuit includes but is not limited to at least one of a data signal circuit, a scan signal circuit and a power signal circuit.

[0047] Based on the above embodiments, in one embodiment of the present application, Figure 6 As shown, Figure 6 is a schematic diagram of a local cross-section of the step area along a direction perpendicular to the substrate (excluding the bending area), the thinned area 11 includes a hollow area 12 , and the hollow area 12 passes through the protective film 10 .

[0048] In this embodiment, the hollow area 12 can be a partial area of ​​the thinned area 11 or the entire area of ​​the thinned area 11. The hollow area 12 is an area where the protective film 10 is completely removed. Since there is no absorption of light by the protective film 10 in this area, it is beneficial to increase the amount of light that can be received by the photosensitive element, improve the imaging effect of the photosensitive element, and thus improve the accuracy of AOI detection.

[0049] The shape of the hollow area 12 can be a hole (ie, a through hole) or other polygonal shapes (eg, a triangle, a rhombus, etc.). The shape of the hollow area 12 can be determined according to actual design requirements or factors such as the type of display device.

[0050] exist Figure 6 The subsequent figures also show the feasible specific structures of the optical adhesive layer OCA, the adhesive layer 80 and the binding structure 20 for bonding the protective film 10. As mentioned above, the binding structure 20 may include a first conductive pad 26, conductive particles 23 and a second conductive substrate 24. The carrier of the conductive particles 23 may include an anisotropic conductive film 25. The first conductive pad 26 is electrically connected to the interconnection trace 100 on the substrate, so that the first conductive pad 26 is electrically connected to the pixel circuit of the driving film layer 90. The first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 25. The second conductive pad 26 is electrically connected to the functional circuit on the chip or FPC.

[0051] Based on the above embodiment, in another embodiment of the present application, Figure 7 As shown, Figure 7 4 is a schematic diagram of a local cross-section of the step region along a direction perpendicular to the substrate. The substrate 40 further includes a groove 41 ; the groove 41 is located on a side of the substrate 40 away from the binding structure 20 .

[0052] The orthographic projection of the binding structure 20 on the substrate 40 and the orthographic projection of the hollow area 12 on the substrate 40 at least partially overlap with the groove 41 .

[0053] In this embodiment, while the protective film 10 includes a hollow area 12, the substrate 40 is further grooved to reduce the absorption of light by the substrate 40 in the grooved area, thereby increasing the transmittance of light in the overlapping area of ​​the hollow area 12 and the groove 41, increasing the amount of light that can be received by the photosensitive element used for AOI detection, and improving the accuracy of AOI detection.

[0054] Similarly, the orthographic projection of the binding structure 20 on the substrate 40 and the orthographic projection of the hollow area 12 on the substrate 40 may partially overlap or completely overlap with the groove 41, that is, the orthographic projection of the hollow area 12 on the substrate 40 covers the groove 41. This is beneficial to increase the area through which light can pass in large quantities, so that the photosensitive element used for AOI inspection can clean and image a larger area of ​​the binding structure 20, thereby achieving comprehensive inspection of the binding structure 20.

[0055] The groove 41 may also be formed by a laser removal process, that is, after the hollow region 12 of the protective film 10 is formed, a laser removal process is further used to partially remove the substrate 40 to form the groove 41 .

[0056] Regarding the specific structure of the substrate 40, in one embodiment of the present application, as shown in FIG. Figure 8 As shown, Figure 8 is a schematic diagram of a local cross-section of the step region along a direction perpendicular to the substrate, wherein the substrate 40 comprises:

[0057] A first flexible film 42, a buffer layer 43 and a second flexible film 44 are sequentially stacked; the buffer layer 43 comprises an inorganic film layer;

[0058] Optionally, the buffer layer 43 is used to isolate the first flexible film 42 and the second flexible film 44 .

[0059] The second flexible membrane 44 is disposed adjacent to the binding structure 20 .

[0060] The groove 41 passes through the first flexible film 42 or penetrates into a part of the first flexible film 42 .

[0061] That is to say, the substrate 40 includes at least one organic layer. Optionally, the organic layer closest to the array layer is a complete structure with uniform thickness in the area corresponding to the binding structure. However, at least another organic layer of the substrate 40 on the side of the organic layer away from the binding structure is thinned in the area corresponding to the binding structure, and is optionally a hollow structure.

[0062] In this embodiment, the arrangement of the double-layer flexible film sandwiching the buffer layer 43 of the substrate 40 can effectively ensure the support performance of the substrate 40. Specifically, the second flexible film 44, as a flexible film closest to the binding structure 20, the thin film transistor and the display pixel, may affect its own flexibility due to problems such as impurity infiltration during the preparation process of the thin film transistor and other components, resulting in breakage in the subsequent high-temperature process and failure to play a good supporting role. The existence of the buffer layer 43 and the first flexible film 42 solves this problem well. The buffer layer 43 exists as a film layer to isolate the first flexible film 42 and the second flexible film 44, isolating impurities from invading the first flexible film 42, and ensuring the support and flexibility of the first flexible film 42. The buffer layer 43 can be made of inorganic materials or metal materials to improve the heat dissipation performance and anti-ultraviolet interference performance of the substrate 40 on the basis of isolation.

[0063] When the substrate 40 has a structure of a double-layer flexible film sandwiching a buffer layer 43, the groove 41 may penetrate the first flexible film 42 (eg Figure 8As shown), the groove 41 may also penetrate partially into the first flexible film 42, that is, the groove 41 is mainly formed in the flexible film on the side away from the binding structure 20, and the groove 41 is usually not formed in the buffer layer 43. This is because, on the one hand, the laser energy required to form the groove 41 in the buffer layer 43 is too large, and it is difficult to control the removal depth of the buffer layer 43, which may completely destroy the substrate 40; on the other hand, if part or all of the buffer layer 43 is removed, the supporting performance of the substrate 40 in the area where the groove 41 is located cannot be guaranteed. When the second flexible film 44 above the groove 41 is broken due to impurities or high-temperature processes, if the buffer layer 43 is also partially or completely penetrated by the groove 41, the substrate 40 in the area where the groove 41 is located may cause complete failure.

[0064] Optionally, the first flexible film 42 and the second flexible film 44 are both polyimide film layers, which have the advantages of high temperature resistance, good ductility and good flexibility, and are one of the best choices for the substrate 40. In addition, due to the arrangement of the thinned area 11 of the protective film 10 and the groove 41 of the substrate 40 in the display device provided in the embodiment of the present application, the negative impact of the large light absorption rate of the polyimide film layer itself on AOI detection is solved. Since the polyimide film layer itself is yellow, it can also be called yellow polyimide film (Yellow Polyimide), abbreviated as YPI.

[0065] exist Figure 8 In the figure, an optical adhesive layer OCA for bonding the protective film 10 and the substrate 40 is also shown. Figure 8 The groove 41 and the hollow area 12 form a trapezoidal shape, which is generally formed during the laser removal process of the protective film 10 , the optical adhesive layer OCA and the first flexible film 42 .

[0066] Optional, still reference Figure 8 , the cross-sectional shape of the groove 41 and the hollow area 12 in the direction perpendicular to the surface of the substrate 40 is a regular trapezoid. The opening area of ​​the regular trapezoid is larger, which can increase the amount of light entering the photosensitive element for AOI inspection to a certain extent, which is beneficial for the photosensitive element to image the area where the binding structure is located. In addition, the area of ​​the side of the regular trapezoid close to the buffer layer 43 is smaller, which is beneficial to ensure the support capacity of the substrate 40. Furthermore, the regular trapezoidal groove 41 and the inclined side of the hollow area 12 can avoid the stress concentration problem caused by steep steps.

[0067] Optional, still reference Figure 8The groove 41 is continuous with the opening side wall of the hollow area 12, that is, the protective film 10, the optical adhesive layer OCA and the first flexible film 42 provided with the opening are smooth and continuous at the end face facing the groove 41 or the hollow area 12, and there is no step at the connection, so a reflective surface can be formed to avoid absorbing ambient light, improve the brightness in the opening area, and facilitate the imaging of the area where the binding structure is located by the photosensitive element.

[0068] It can be understood that this embodiment is described by taking the design in which the substrate 40 includes two layers of polyimide sandwiching an inorganic buffer layer as an example, but in other optional embodiments of the present application, the substrate 40 can also include a pure organic film layer (such as a single layer or multiple layers of polyimide) or a stacked structure including multiple organic film layers and at least one inorganic film layer.

[0069] Based on the above embodiment, in another embodiment of the present application, Fig. 9 As shown, Fig. 9 is a schematic diagram of a local cross-section of the step region along a direction perpendicular to the substrate, wherein the display device further comprises:

[0070] The lens structure 50 located in the thinned area 11 includes a plano-concave lens; the plano-concave lens includes a first curved surface cf1 convex toward the substrate 40 .

[0071] Specifically, the lens material is generally an organic material, for example, it can be a UV glue, and the UV glue can include acrylic resin (Aacrylic Resin). In some embodiments of the present application, the UV glue can also include transparent polyimide. The formation process of the lens structure 50 can generally include: by dripping UV glue, it is set in the groove 41 and the hollow area 12. After dripping, a concave liquid surface can be formed by the tension of the liquid, and the first curved surface cf1 is formed after curing. In addition, the lens structure 50 can also be formed by dripping UV glue at the edge of the groove 41. During the dripping process, the glue accumulates in the edge area of ​​the groove 41, and a small amount of glue flows to the center of the groove 41, thereby forming the first curved surface cf1.

[0072] Optionally, the lens structure 50 fills the groove 41 and the hollow area 12, and covers the boundary area between the groove 41 and the hollow area 12, so as to improve the bonding ability between the protective film 10 and the substrate 40 and avoid film separation. At the same time, the lens material forming the lens structure 50 can also be a hydrophobic material, so that even if the first flexible film 42 is opened by the formation of the groove, the lens structure 50 formed by the hydrophobic material can also play a good sealing role, so as to seal the opening of the substrate 40 caused by the groove 41, improve the sealing performance, and improve the ability to isolate water and oxygen.

[0073] The lens structure 50 may be formed after the thinning area 11 is formed. Similarly, the first curved surface cf1 of the lens structure 50 plays a magnifying effect of a concave lens to optimize the imaging effect of the photosensitive element used for AOI inspection.

[0074] refer to Fig.10 , Fig.10 is a schematic diagram of a local cross section of the step region along a direction perpendicular to the substrate, Fig.10 In the structure shown, when the thinned region 11 includes a hollow region 12 and the substrate 40 includes a groove 41 , the lens structure 50 may also be formed in the hollow region 12 and the groove 41 .

[0075] Based on the above embodiment, in another embodiment of the present application, Fig.11 As shown, Fig.11 is a partial cross-sectional schematic diagram of the step region along a direction perpendicular to the substrate. The groove 41 penetrates part of the first flexible film 42 , and the first flexible film 42 includes a second curved surface cf2 facing the side of the protection film 10 , and the second curved surface cf2 convexes toward the buffer layer 43 .

[0076] Specifically, the first flexible film 42 forms a groove on the side facing the protective film 10 , which is a non-through groove. The groove opening faces the protective film 10 , and the cross-sectional shape of the groove along the direction perpendicular to the surface of the substrate 40 includes at least a circular portion.

[0077] The second curved surface cf2 is convex toward the buffer layer 43 .

[0078] The projection of the second curved surface cf2 on the plane where the substrate is located covers the binding structure.

[0079] In this embodiment, during the preparation process of the groove 41, the removal degree of each area of ​​the groove 41 can be controlled by controlling the laser power or other parameters such as the concentration of the etching material, so as to form the following: Fig.11 The second curved surface cf2 shown, and the groove 41 of the second curved surface cf2 substantially play a magnifying effect similar to a concave lens, so as to optimize the imaging effect of the photosensitive element used for AOI inspection.

[0080] The binding structure 20 provided in the embodiment of the present application is described below. Fig.12 As shown, Fig.12 2 is a schematic diagram of a local cross-section of the step region along a direction perpendicular to the substrate. The binding structure 20 includes: a first binding structure 21 and a second binding structure 22 .

[0081] The first binding structure 21 includes a first conductive film 211 located on the substrate 40 .

[0082] The second binding structure 22 includes a second conductive film 221 located on the substrate 40 . The first conductive film 211 and the second conductive film 221 both include conductive particles, and the first conductive film 211 and the second conductive film 221 are disposed in the same layer.

[0083] The step area BB also includes interconnection wiring 100 .

[0084] The first binding structure 21 and the second binding structure 22 are electrically connected via the conductive particles 212 of the first conductive film 211 , the conductive particles 222 of the second conductive film 221 , and the interconnection line 100 .

[0085] Attached Fig.12 1 also shows a first pad 214 of the first binding structure 21 and a second pad 213 of the first binding structure 21. The first pad 214 is electrically connected to the interconnection trace 100. The first pad 214 is electrically connected to the second pad 213 through the conductive particles 212 of the first binding structure 21. The second pad 213 is electrically connected to the pin of the chip or functional circuit. Fig.12 Also shown is a third pad 224 of the second binding structure 22 and a fourth pad 223 of the second binding structure 21, wherein the third pad 224 is electrically connected to the interconnection trace 100, the third pad 224 is electrically connected to the fourth pad 223 through the conductive particles 222 of the second binding structure 22, and the fourth pad 223 is electrically connected to a pad of a FPC (Flexible Printed Circuit) or a functional circuit. Various devices and traces can be arranged on the FPC.

[0086] Accordingly, still refer to Fig.12 , when the number of the conductive films and the number of the pads are both two, the number of the thinned regions 11 is two, the orthographic projection of the first conductive film on the substrate 40 at least partially overlaps with the orthographic projection of one of the thinned regions 11 on the substrate 40, and the orthographic projection of the second conductive film on the substrate 40 at least partially overlaps with the orthographic projection of another of the thinned regions 11 on the substrate 40. In this embodiment, by setting the number of thinned regions 11 to two, the first conductive film and the second conductive film can be inspected by AOI through the two thinned regions 11, respectively.

[0087] Optionally, in some embodiments of the present application, the number of the binding structure may also be one, see Fig.13 , Fig.134 is a partial cross-sectional schematic diagram of the step region along a direction perpendicular to the substrate. The binding structure 20 includes: at least one first conductive pad 26, a plurality of conductive particles 23 and at least one second conductive pad 24 which are sequentially stacked on the substrate 40.

[0088] The display device further includes: a functional circuit. The step area BB further includes an interconnection line 100, which is electrically connected to the first conductive pad 26, and the first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 23. The first conductive pad 26 is electrically connected to the interconnection line 100 on the substrate, so that the first conductive pad 26 is electrically connected to the pixel circuit of the driving film layer 90. The first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 25. The second conductive pad 26 is electrically connected to the functional circuit on the chip or FPC. As described above, the functional circuit may include at least one of a scan signal circuit, a data signal circuit, and a power signal circuit.

[0089] In this embodiment, the carrier of the conductive particles may be an anisotropic conductive film 25. The second conductive pad 24 may be a conductive pad of an FPC 90, and the FPC 90 may be used to arrange chips, wiring and various devices.

[0090] Optional, still reference Fig.13 The hollow area 12 is disposed at the edge of the protective film 10 and the optical adhesive layer OCA to avoid the hollow area 12 being used as a dust storage area. Similarly, in some embodiments of the present application, the thinned area can also be disposed at the edge of the protective film 10 to avoid dust storage in the thinned area.

[0091] The following is a description of a method for manufacturing a display device provided in an embodiment of the present application. The method for manufacturing a display device described below can be referenced to the display device described above.

[0092] Accordingly, the present application also provides a method for preparing a display device, such as Fig.14 As shown, Fig.14 is a schematic flow chart of a method for preparing the display device, the method for preparing the display device comprising:

[0093] S101: Provide a substrate 40, wherein the substrate 40 includes a step region BB. Fig.15 , Fig.15: is a schematic diagram of the cross-sectional structure of the substrate 40. The step area BB of the substrate 40 refers to other areas except the display area AA for setting display pixels, and the step area BB also includes a bending area bending, and most of the step area BB can be bent to the back of the display area of ​​the substrate 40 by bending the bending area bending, so as to achieve "hiding" of the step area BB and improve the screen-to-body ratio of the display device.

[0094] S102: forming a binding structure 20 on one side of the step area BB. Fig.16 , Fig.16 Schematic diagram of the cross-sectional structure of the substrate 40 and its surface structure after step S102. The binding method of the binding structure 20 and the substrate 40 includes but is not limited to COF (Chip on Film) and COP (Chip on Panel). Fig.16 Also shown are the driving film layer 90, polarizer 60 and protective cover 70 located in the display area AA, and the adhesive layer 80 for fixing or encapsulating the polarizer 60, protective cover 70 and binding structure 20. The driving film layer 90 includes at least a plurality of pixel circuits composed of a thin film transistor array. In some embodiments, the driving film layer 90 also includes a plurality of light-emitting units, including but not limited to OLED light-emitting units and Micro-LED light-emitting units, and the anode of the light-emitting unit is electrically connected to the pixel circuit. In addition Figure 4 and Figure 5 Also shown is an interconnection line 100 electrically connected to the pixel circuit, and the interconnection line 100 includes but is not limited to a data fan-out line, a gate fan-out line, a power fan-out line, and the like.

[0095] In some embodiments of the present application, reference is still made to Fig.16 The binding structure 20 may specifically include a first conductive pad 26, conductive particles 23, and a second conductive substrate 24, and the carrier of the conductive particles 23 may include an anisotropic conductive film 25. The first conductive pad 26 is electrically connected to the interconnection trace 100 on the substrate, so that the first conductive pad 26 is electrically connected to the pixel circuit of the driving film layer 90. The first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 25. The second conductive pad 26 is electrically connected to the functional circuit on the chip or FPC.

[0096] S103: forming a protective film 10 on the side of the step area BB away from the binding structure 20. Fig.17 , Fig.17 FIG. 4 is a schematic diagram of the cross-sectional structure of the substrate 40 and its surface structure after step S103 .

[0097] S104: Processing the protective film 10 to form a thinned region 11 in the protective film 10, wherein the orthographic projection of the thinned region 11 on the substrate 40 at least partially overlaps with the orthographic projection of the binding structure 20 on the substrate 40. Figure 4 , Figure 4 4 is a schematic diagram of the cross-sectional structure of the display device formed after step S104 along a direction perpendicular to the surface of the substrate 40 .

[0098] Optional, such as Figure 6 As shown, the thinned area includes a hollow area 12, and the hollow area 12 passes through the protective film 10. Figure 6 The optical adhesive layer OCA and the adhesive layer 80 used to bond the protective film 10 and the feasible specific structure of the binding structure 20 are also shown. As mentioned above, the binding structure 20 may include a first conductive pad 26, conductive particles 23 and a second conductive substrate 24. The carrier of the conductive particles 23 may include an anisotropic conductive film 25. The first conductive pad 26 is electrically connected to the interconnection trace 100 on the substrate, so that the first conductive pad 26 is electrically connected to the pixel circuit of the driving film layer 90. The first conductive pad 26 is electrically connected to the second conductive pad 24 through the conductive particles 25. The second conductive pad 26 is electrically connected to the functional circuit on the chip or FPC.

[0099] In this embodiment, the hollow area can be a partial area of ​​the thinned area 11 or the entire area of ​​the thinned area 11. The hollow area is an area where the protective film 10 is completely removed. Since there is no absorption of light by the protective film 10 in this area, it is beneficial to increase the amount of light that can be received by the photosensitive element, improve the imaging effect of the photosensitive element, and thus improve the accuracy of AOI detection.

[0100] The shape of the hollow area can be a hole (ie, a through hole) or other polygonal shapes (eg, a triangle, a rhombus, etc.). The shape of the hollow area can be determined according to actual design requirements or factors such as the type of display device.

[0101] On the basis of the above embodiments, in one embodiment of the present application, the processing of the protective film 10 includes:

[0102] The protective film 10 is laser cut using a carbon dioxide laser to form a hollow area in the protective film 10 .

[0103] Generally, the protective film 10 has a high absorption rate for carbon dioxide laser, so the protective film 10 can be laser cut using carbon dioxide laser to form the hollow area quickly and efficiently.

[0104] Based on the above embodiment, in another embodiment of the present application, Fig.18 As shown, Fig.18 : is a schematic diagram of a process of manufacturing the display device, wherein after processing the protective film 10, the method further includes:

[0105] S105 : performing laser cutting processing on the substrate 40 by using an ultraviolet laser to form a groove located on a side of the substrate 40 away from the binding structure 20 .

[0106] The orthographic projection of the binding structure 20 on the substrate 40 and the orthographic projection of the hollow area on the substrate 40 at least partially overlap with the groove.

[0107] Since the main component of the substrate 40 is a polyimide film layer, which has a high absorption rate for ultraviolet laser, the groove can be formed quickly and efficiently by laser cutting the substrate 40 with ultraviolet laser.

[0108] Accordingly, the present application also provides an electronic device, such as Fig.19 As shown, Fig.19 is a schematic diagram of the structure of an electronic device A100, wherein the electronic device A100 includes a display device as described in any of the above embodiments.

[0109] In summary, the embodiments of the present application provide a display device and a preparation method thereof, and an electronic device, wherein the protective film of the display device includes a thinned area, and the orthographic projection of the thinned area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate. In this way, during the AOI detection of the binding effect of the binding structure, the absorption of light by the protective film in the thinned area is reduced, and the amount of light entering the photosensitive element is increased, thereby improving the clarity of the image acquired by the photosensitive element, meeting the imaging requirements of the AOI detection, and meeting the requirements for accurate detection of the binding effect of the binding structure.

[0110] The features described in the embodiments of the present specification may be replaced or combined with each other. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments may be referenced to each other.

[0111] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A display device, characterized in that: include: a substrate, the substrate comprising a step region; a binding structure located on one side of the step area; A protective film is located on the side of the step area away from the binding structure, the protective film includes a thinned area, the thinned area includes a hollowed area, the hollowed area passes through the protective film, the orthographic projection of the thinned area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate, and the orthographic projection of the hollowed area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate.

2. The display device according to claim 1, characterized in that The substrate further comprises a groove; the groove is located on a side of the substrate away from the binding structure; The orthographic projection of the binding structure on the substrate and the orthographic projection of the hollow area on the substrate at least partially overlap with the groove.

3. The display device according to claim 2, characterized in that: The substrate comprises: A first flexible film, a buffer layer, and a second flexible film are sequentially stacked; the buffer layer comprises an inorganic film layer; The second flexible membrane is disposed adjacent to the binding structure; The groove penetrates through the first flexible film or penetrates into a part of the first flexible film.

4. The display device according to claim 3, characterized in that: The orthographic projection of the hollow area on the substrate covers the groove.

5. The display device according to claim 3, characterized in that: The groove partially penetrates into the first flexible film, and the first flexible film includes a second curved surface facing a side of the protection film, and the second curved surface is convex toward the buffer layer.

6. The display device according to claim 3, characterized in that: The first flexible film and the second flexible film are both polyimide film layers.

7. The display device according to claim 1, characterized in that The display device further includes: a lens structure located in the thinned region, the lens structure comprising a plano-concave lens; The plano-concave lens includes a first curved surface convex toward the substrate.

8. The display device according to claim 1, characterized in that: The binding structure includes a first binding structure and a second binding structure; The first binding structure includes a first conductive film located on the substrate; The second binding structure includes a second conductive film located on the substrate, the first conductive film and the second conductive film both include conductive particles, and the first conductive film and the second conductive film are arranged in the same layer; The step area also includes interconnection routing; The first binding structure and the second binding structure are electrically connected through the conductive particles of the first conductive film, the conductive particles of the second conductive film, and the interconnection wiring.

9. The display device according to claim 8, characterized in that: The first binding structure further includes a chip located on a side of the first conductive film away from the substrate; The second binding structure further includes: a flexible circuit board located on a side of the second conductive film away from the substrate.

10. The display device according to claim 8, characterized in that: The number of the thinned regions is two, the orthographic projection of the first conductive film on the substrate at least partially overlaps with the orthographic projection of one of the thinned regions on the substrate, and the orthographic projection of the second conductive film on the substrate at least partially overlaps with the orthographic projection of another of the thinned regions on the substrate.

11. The display device according to claim 1, characterized in that: The display device further includes: a functional circuit; The binding structure comprises: at least one first conductive pad, a plurality of conductive particles and at least one second conductive pad which are sequentially stacked on the substrate; The step region further includes an interconnection line, the interconnection line is electrically connected to the first conductive pad, and the first conductive pad is electrically connected to the second conductive pad through the conductive particles; The second conductive pad is electrically connected to the functional circuit.

12. A method for preparing a display device, characterized in that: include: providing a substrate, the substrate comprising a step region; forming a binding structure on one side of the step area; forming a protective film on a side of the step area away from the binding structure; The protective film is processed to form a thinned area in the protective film, wherein the thinned area includes a hollow area, wherein the hollow area passes through the protective film, and the orthographic projection of the thinned area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate, and the orthographic projection of the hollow area on the substrate at least partially overlaps with the orthographic projection of the binding structure on the substrate.

13. The method according to claim 12, characterized in that The processing of the protective film comprises: The protective film is laser cut using a carbon dioxide laser to form a hollow area in the protective film.

14. The method according to claim 13, characterized in that After the protective film is processed, the method further comprises: Using ultraviolet laser to perform laser cutting on the substrate to form a groove located on a side of the substrate away from the binding structure; The orthographic projection of the binding structure on the substrate and the orthographic projection of the hollow area on the substrate at least partially overlap with the groove.

15. An electronic device, characterized in that: Comprising the display device as described in any one of claims 1-11.

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