Back panel and preparation method thereof, and display device

Abstract

The present application provides a backplane and a preparation method thereof, and a display device, which relate to the field of display technology and can improve the light output rate of the backplane and reduce the production cost and power consumption of the backplane. The backplane includes: a substrate, which includes a circuit structure layer. A first reflective layer, which is arranged on the bearing surface of the substrate; the first reflective layer includes a plurality of through holes arranged at intervals. A plurality of light-emitting diode chips; one of the plurality of light-emitting diode chips is located in one of the plurality of through holes, and the light-emitting diode chip is electrically connected to the circuit structure layer; the circuit structure layer is used to drive the light-emitting diode chip to emit light. A plurality of optical structures, one of the plurality of optical structures covers the light-emitting surface of one of the plurality of light-emitting diode chips, and is in direct contact with the light-emitting surface of the light-emitting diode chip.

Description

Technical Field

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

[0002] Liquid crystal display (LCD), mini light emitting diode (Mini LED), and micro light emitting diode (Micro LED) are self-luminous light-emitting devices that can be used as backlight sources for passive display devices such as liquid crystal display (LCD), and can also be directly used as pixel units in display panels. The performance of light-emitting diodes is stable, and the cost of liquid crystal display panels is low and the service life is long, making the application scenarios of the two increasingly diverse. Summary of the invention

[0003] Embodiments of the present invention provide a backplane and a method for manufacturing the same, and a display device, which can improve the light extraction rate of the backplane and reduce the production cost and power consumption of the backplane.

[0004] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0005] On the one hand, a backplane is provided, comprising: a substrate, wherein the substrate comprises a circuit structure layer.

[0006] The first reflective layer is arranged on the bearing surface of the substrate; the first reflective layer comprises a plurality of through holes arranged at intervals.

[0007] A plurality of light-emitting diode chips; one of the plurality of light-emitting diode chips is located in one of the plurality of through holes, and the light-emitting diode chip is electrically connected to the circuit structure layer; the circuit structure layer is used to drive the light-emitting diode chip to emit light.

[0008] A plurality of optical structures, wherein the light emitting surfaces of the plurality of optical structures are curved surfaces; an optical structure among the plurality of optical structures covers the light emitting surface of one of the plurality of light emitting diode chips and is in direct contact with the light emitting surface of the light emitting diode chip.

[0009] In some embodiments of the present application, the through hole includes a first sub-through hole and a second sub-through hole which are connected and sequentially away from the substrate.

[0010] The aperture of the first sub-through hole is smaller than the aperture of the second sub-through hole.

[0011] The optical structure is in direct contact with at least a hole wall of the first sub-through hole.

[0012] In some embodiments of the present application, a side surface of the light emitting diode chip away from the carrying surface of the substrate has a first maximum distance from the carrying surface of the substrate.

[0013] A second maximum distance is formed between a side surface of the first reflective layer away from the carrying surface of the substrate and the carrying surface of the substrate.

[0014] The first maximum spacing is greater than the second maximum spacing.

[0015] In some embodiments of the present application, the first reflective layer includes a first sub-reflective layer and a second sub-reflective layer; the first sub-through hole is located on the first sub-reflective layer, and the second sub-through hole is located on the second sub-reflective layer.

[0016] In some embodiments of the present application, there is a gap between the hole wall of the through hole and the light emitting diode chip.

[0017] The substrate also includes a second reflective layer.

[0018] The gap exposes at least a portion of a surface of the second reflective layer close to the first reflective layer.

[0019] In some embodiments of the present application, the second reflective layer is located on a side of the circuit structure layer close to the first reflective layer; the second reflective layer includes a plurality of hollow areas, the circuit structure layer includes a plurality of solder pads, one of the plurality of hollow areas exposes one of the plurality of solder pads, and the light-emitting diode chip is electrically connected to the solder pad.

[0020] In some embodiments of the present application, the second reflective layer includes a first sub-transparent insulating layer, a metal reflective layer, and a second sub-transparent insulating layer sequentially stacked along the thickness direction of the substrate.

[0021] In some embodiments of the present application, the substrate also includes a second reflective layer; the second reflective layer is located on a side of the circuit structure layer away from the first reflective layer; the circuit structure layer has a plurality of metal routing areas, and a light-transmitting area located between two adjacent metal routing areas; the circuit structure layer includes a pad arranged on the metal routing area; the light-transmitting area is used to transmit part of the light emitted by the light-emitting diode chip that is reflected by the second reflective layer.

[0022] In some embodiments of the present application, the backplane further includes an adhesive layer, which is located on a side of the first reflective layer close to the substrate and is used to adhere the first reflective layer to the substrate.

[0023] In some embodiments of the present application, the material constituting the optical structure includes a transparent colloid material and a light conversion material mixed with the transparent colloid material, and the light conversion material is used to convert the color of the light emitted by the light emitting diode chip.

[0024] In some embodiments of the present application, the backplane further includes a light conversion layer, and the light conversion layer is located on a side of the optical structure away from the substrate.

[0025] On the other hand, a display device is provided, comprising the above-mentioned back plate and a display panel.

[0026] On the other hand, a method for preparing a backplane is provided, wherein the backplane includes a substrate, the substrate includes a circuit structure layer, and the circuit structure layer includes a plurality of pads.

[0027] The method for preparing the backplane comprises:

[0028] A first ink film is formed on the supporting surface of the substrate, and a plurality of through holes are formed on the first ink film to form a first reflective layer.

[0029] On the substrate having the first reflective layer formed thereon, a plurality of light emitting diode chips are electrically connected to a plurality of the pads in a one-to-one correspondence.

[0030] On a side of the multiple LED chips away from the substrate, multiple optical structures are formed by a dispensing process, and the light-emitting surfaces of the optical structures are curved surfaces; one optical structure among the multiple optical structures covers the light-emitting surface of one LED chip among the multiple LED chips and is in direct contact with the light-emitting surface of the LED chip.

[0031] In some embodiments of the present application, forming a first ink film includes:

[0032] A first sub-ink film is formed on the bearing surface of the substrate, and a first sub-through hole is formed on the first sub-ink film.

[0033] A second sub-ink film is formed on the first sub-ink film, and a second sub-through hole is formed on the second sub-ink film, and the second sub-through hole is connected to the first sub-through hole, and the first sub-through hole and the second sub-through hole constitute the through hole.

[0034] In some embodiments of the present application, before forming the first reflective layer, the method for preparing the backplane further includes:

[0035] A second ink film is formed on the bearing surface of the substrate, and a plurality of hollow areas are formed on the second ink film to expose the pads in the circuit structure layer, so as to form the second reflective layer.

[0036] Alternatively, a first sub-transparent insulating layer is formed on the supporting surface of the substrate.

[0037] A metal reflective layer is formed on the first sub-transparent insulating layer.

[0038] A second sub-transparent insulating layer is formed on the metal reflective layer; the first sub-transparent insulating layer, the metal reflective layer and the second sub-transparent insulating layer constitute a second reflective layer.

[0039] On the other hand, a method for preparing a backplane is provided, wherein the backplane includes a substrate, the substrate includes a circuit structure layer, and the circuit structure layer includes a plurality of pads.

[0040] The method for preparing the backplane comprises:

[0041] The plurality of light emitting diode chips are electrically connected to the plurality of bonding pads in a one-to-one correspondence.

[0042] An adhesive layer is formed on the non-functional surface of the reflective sheet, and a first protective film is attached to the adhesive layer.

[0043] A plurality of through holes are formed on the reflection sheet bonded to the first protection film, wherein the through holes penetrate the reflection sheet, the bonding layer and the first protection film.

[0044] The first protective film is removed, and the reflective sheet is attached to the supporting surface of the substrate through the adhesive layer. The plurality of light-emitting diode chips are located in the plurality of through holes in a one-to-one correspondence.

[0045] On the side of the multiple light-emitting diodes away from the substrate, multiple optical structures are formed by a dispensing process, and the light-emitting surfaces of the optical structures are curved surfaces; one optical structure among the multiple optical structures covers the light-emitting surface of one of the multiple light-emitting diode chips and is in direct contact with the light-emitting surface of the light-emitting diode chip.

[0046] In some embodiments of the present application, a plurality of optical structures are formed by a dispensing process, including:

[0047] A transparent colloid material and a light conversion material are mixed and a plurality of optical structures are formed by a dispensing process; wherein the light conversion material is used to convert the color of the light emitted by the light emitting diode chip.

[0048] The embodiment of the present application provides a backplane and a preparation method thereof, wherein a first reflective layer and an optical structure are provided in the backplane. On the one hand, since the light-emitting surface of the optical structure is a curved surface, the light emission rate can be improved, that is, the light-emitting efficiency of the light-emitting diode chip is improved; on the other hand, if there is light propagating toward one side of the substrate, the presence of the first reflective layer can change the propagation direction of the light, thereby further improving the light-emitting efficiency of the light-emitting diode chip. After the light-emitting efficiency of the light-emitting diode chip is improved, the power consumption of the backplane can be reduced; on the other hand, since there are multiple optical structures in the present application, compared with the protective layer covering the entire layer in the related art, the amount of packaging glue used can be reduced, thereby effectively reducing the production cost of the backplane. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1a A schematic structural diagram of a backplane provided by an embodiment of the present invention;

[0051] Figure 1b A schematic top view of two optical structures and a light-emitting diode chip provided in an embodiment of the present invention;

[0052] Figure 1c A schematic diagram of the connection relationship between a light-emitting diode chip and a circuit structure layer provided in an embodiment of the present invention;

[0053] Figure 2 A schematic diagram of the structure of a backplane provided for related technology;

[0054] Figure 3a and Figure 3b A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0055] Figure 3c for Figure 3a A schematic diagram of the enlarged structure at A in the middle;

[0056] Figure 3d A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0057] Figure 3e for Figure 3d A schematic diagram of the enlarged structure at B in the middle;

[0058] Figure 4a-4c A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0059] Figure 5a-5d A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0060] Figure 6 A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0061] Figure 7 A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0062] Figure 8 A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0063] Figure 9a-9c A schematic diagram of the structure of another backplane provided by an embodiment of the present invention;

[0064] Fig.10a A schematic flow chart of a method for preparing a backplane provided in an embodiment of the present invention;

[0065] Figure 10b-Figure 10c A schematic diagram of a process for preparing a backplane provided by an embodiment of the present invention;

[0066] Figure 11a-Figure 11b A schematic diagram of another process for preparing a backplane provided by an embodiment of the present invention;

[0067] Figure 12a-12d A schematic diagram of another process for preparing a backplane provided by an embodiment of the present invention;

[0068] Fig.13a A schematic flow chart of another method for preparing a backplane provided by an embodiment of the present invention;

[0069] Figure 13b-13g A schematic diagram of a preparation process of another backplane provided in an embodiment of the present invention.

[0070] Reference numerals:

[0071] 1-backplane; 10-substrate; 100-substrate; 101-circuit structure layer; 1010-metal routing area; 1011-light-transmitting area; 11-first reflective layer; 111-first sub-reflective layer; 112-second sub-reflective layer; 110-through hole; 1101-first sub-through hole; 1102-second sub-through hole; 12-light-emitting diode chip; 120-light-emitting layer; 13-optical structure; 130-light-emitting surface; 14-second reflective layer; 141-first sub-transparent insulating layer; 142-metal reflective layer; 143-second sub-transparent insulating layer; 15-insulating layer; 16-adhesive layer; 17-light conversion layer; 18-first protective film; 19-second protective film; 110-hydrophobic layer; 2-light; 20-totally reflected light; 3-protective layer; 4-conductive material. DETAILED DESCRIPTION

[0072] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0073] The present application provides a display device, which includes a backplane and a display panel, wherein the display panel is, for example, a liquid crystal display panel, and the backplane is used to provide a light source for the display panel.

[0074] like Figure 1a As shown, the backplane 1 includes: a substrate 10 , and the substrate 10 includes a circuit structure layer 101 .

[0075] The base plate 10 may further include a substrate 100 for carrying the circuit structure layer 101. The substrate 100 may be a flexible material, such as polyimide; the substrate 100 may also be a rigid material, such as glass, silicon or PCB (Printed Circuit Board), etc., which is not limited in the present application.

[0076] The first reflective layer 11 is disposed on the bearing surface of the substrate 10. The bearing surface of the substrate 10 is the functional surface of the substrate 10, or can be understood as the front surface of the substrate 10, and the circuit structure layer 101 is more toward the functional surface of the substrate 10. The first reflective layer 11 includes a plurality of through holes 110 arranged at intervals. The first reflective layer 11 is used to reflect the light 2 incident on its surface. The through hole 110 is used to accommodate the light emitting diode chip, so the shape and size of the through hole 110 need to be selected according to the size and shape of the light emitting diode chip.

[0077] In some embodiments of the present application, the top view of the through hole 110 is a regular shape such as a circle, a rectangle, a square, etc., or the top view of the through hole 110 may also be an irregular shape, which is not limited in the present application.

[0078] In some embodiments of the present application, the material of the first reflective layer 11 is an organic or inorganic reflective material such as a photosensitive material or a thermally curable material, and its reflectivity may be, for example, approximately in the range of 70% to 99%.

[0079] In some embodiments of the present application, the material of the first reflective layer 11 is white ink, and the reflectivity of the white ink to the light 2 is about 90%; or the first reflective layer 11 can be a white reflective sheet, and the white reflective sheet can be bonded to the supporting surface of the substrate 10, and the reflectivity of the white reflective sheet to the light 2 is about 98%.

[0080] In some embodiments of the present application, the white reflective sheet includes micro-air bubbles, and the diameter of the micro-air bubbles is, for example, 1 μm to 5 μm. After the through hole 110 is formed in the white reflective sheet with micro-air bubbles, due to the particularity of the micro-air bubble structure in the white reflective sheet, the light incident from the hole wall of the through hole 110 to the reflection can still be emitted from the reflective sheet, so the white reflective sheet with micro-air bubbles has a higher reflectivity to the light 2.

[0081] In some embodiments of the present application, the thickness of the first reflective layer 11 is, for example, 50 μm, 100 μm, 150 μm, 180 μm, 300 μm, etc., which can be selected according to actual needs.

[0082] A plurality of light emitting diode (LED) chips 12; one of the plurality of LED chips 12 is located in one of the plurality of through holes 110; and the LED chip 12 is electrically connected to the circuit structure layer 101, and the circuit structure layer 101 is used to provide an electrical signal to the LED chip 12.

[0083] In some embodiments of the present application, the circuit structure layer 101 structure includes a pad, and the electrode of the light emitting diode chip 12 is electrically connected to the pad.

[0084] In some embodiments of the present application, the cross-sectional dimensions (parameters such as length, width, diagonal or diameter) of the LED chip 12 are between about 100 μm and about 300 μm; the thickness of the LED chip 12 is, for example, 100 μm.

[0085] In some embodiments of the present application, Figure 1bAs shown, when the top view of the LED chip 12 is rectangular, the cross-sectional shape of the through hole 110 is, for example, an ellipse; when the top view of the LED chip 12 is a square, the cross-sectional shape of the through hole 110 is, for example, a circle; in the above two cases, the shape of the LED chip 12 matches the cross-sectional shape of the through hole 110, and the area of ​​the through hole 110 is larger, which can improve the light output rate of the LED chip.

[0086] like Figure 1c As shown, the light-emitting diode chip 12 includes a light-emitting layer and an N electrode and a P electrode; the light-emitting layer of the light-emitting diode chip 12 emits light in 360 degrees. If the N electrode and the P electrode are made of non-translucent metal, no light will be emitted in the area where the N electrode and the P electrode are set in the light-emitting diode chip 12. In some embodiments of the present application, the N electrode and the P electrode of the light-emitting diode chip 12 are connected to the pads ( Figure 1c The pads are connected to electrical elements such as thin film transistors and capacitors in the circuit structure layer 101 and are used to provide electrical signals to the light-emitting diode chip 12.

[0087] Those skilled in the art will appreciate that, for ease of illustration, in the drawings other than FIG. 1 c of the present application, a rectangular frame is used to represent the light-emitting diode chip 12 , and the rectangular frame does not constitute a limitation on the shape, structure, etc. of the LED chip.

[0088] The light emitting color of the light emitting diode chip 12 can be, for example, any one of the three primary colors, or can be white. In some embodiments of the present application, the light emitting diode chip 12 is a blue light LED chip.

[0089] There are multiple optical structures 13, and the light emitting surfaces 130 of the multiple optical structures 13 are curved surfaces; one optical structure 13 among the multiple optical structures 13 covers the light emitting surface of one LED chip 12 among the multiple LED chips 12 and is in direct contact with the light emitting surface of the LED chip 12.

[0090] The material of the optical structure 13 at least includes a transparent colloid material, and the transparent colloid material is, for example, a packaging glue, and the packaging glue is, for example, at least one of silicone, epoxy glue, and acrylic glue. The optical structure 13 is in direct contact with the light-emitting surface of the LED chip 12, that is, there is no gap between the optical structure 13 and the light-emitting surface of the LED chip 12; and those skilled in the art can understand that the optical structure 13 made of packaging glue can be attached to the LED chip 12 and wrap the LED chip 12. In some embodiments of the present application, the optical structure 13 is prepared by a dispensing process.

[0091] In some embodiments of the present application, the optical structure 13 is an optical lens, such as a convex lens. When the optical structure 13 is a convex lens, it has the function of converging light, and can improve the light extraction efficiency of the LED chip 12.

[0092] In some embodiments of the present application, the refractive index of the optical structure 13 is approximately in the range of 1.3 to 1.7.

[0093] like Figure 1a As shown, the light emitting surface 130 (the surface on the side away from the substrate 10) of each optical structure 13 is a curved surface with a certain curvature. When the light 2 emitted from the light-emitting diode chip 12 is incident on the light emitting surface 130 of the optical structure 13, due to the small incident angle, most of the light 2 will be emitted normally, and part of the light 2 will be totally reflected on the light emitting surface 130 of the optical structure 13. The light 2 that is totally reflected is called totally reflected light 20. When the totally reflected light 20 propagates in the optical structure 13 to the first reflective layer 11, it will be reflected by the first reflective layer 11 and emitted along the side away from the substrate 10.

[0094] like Figure 2 As shown, in the related art, the backplane 1 includes a substrate 10, a light-emitting diode chip 12 electrically connected to a circuit structure layer 101 in the substrate 10, and a protective layer 3. The material of the protective layer 3 is a packaging glue, and the entire layer covers the light-emitting diode chip 12. However, since the light-emitting surface of the protective layer 3 (the surface on the side away from the substrate 10) is a plane, part of the light 2 emitted from the light-emitting diode chip 12 has a larger incident angle at the light-emitting surface of the protective layer 3, and the part of the light 2 with a larger incident angle will be totally reflected. The light 2 that is totally reflected is called totally reflected light 20, that is, Figure 2 The totally reflected light 20 shown in the figure will propagate in the direction toward the side of the substrate 10. This part of the totally reflected light 20 cannot be used because it cannot propagate in the direction away from the side of the substrate 10, which leads to low light extraction efficiency of the LED chip 12 and high power consumption of the backplane 1. In addition, the protective layer 3 covers the entire LED chip 12, and the amount of packaging glue used is large, resulting in a high production cost of the backplane.

[0095] In the present application, the back plate 1 is provided with a first reflective layer 11 and an optical structure 13. On the one hand, since the light emitting surface 130 of the optical structure 13 is a curved surface, the light 2 is not easy to be totally reflected on the curved surface, the amount of totally reflected light 20 is small, and the normally emitted light 2 is large, thereby improving the light extraction efficiency of the light emitting diode chip 12; on the other hand, the propagation direction of the totally reflected light 20 and other light 2 propagating toward the side of the substrate 10 will change after encountering the first reflective layer 11, and can propagate toward the side away from the substrate 10 again, thereby further improving the light extraction efficiency of the light emitting diode chip 12. After the light extraction efficiency of the light emitting diode chip 12 is improved, the power consumption of the back plate 1 can be reduced; on the other hand, since there are multiple optical structures 13 in the present application, under the premise of the same thickness, the present application can reduce the amount of packaging glue used compared with the structure covered by the protective layer 13 in the related art, thereby effectively reducing the production cost of the back plate 1; on the other hand, the optical structure 13 covers the LED chip 12, which can protect the LED chip 12 and reduce the probability of the LED chip 12 being damaged.

[0096] In some embodiments of the present application, Figure 3a , Figure 3b and Figure 3d As shown, the through hole 110 includes a first sub-through hole 1101 and a second sub-through hole 1102 which are connected and sequentially away from the substrate 10; wherein the aperture of the first sub-through hole 1101 is smaller than the aperture of the second sub-through hole 1102, and the optical structure 13 is in direct contact with at least the hole wall of the first sub-through hole 1101.

[0097] For example, Figure 3a As shown, the difference between the aperture d1 of the first sub-through hole 1101 and the aperture d2 of the second sub-through hole 1102 is approximately in the range of 0.4 mm to 1.0 mm.

[0098] like Figure 3a , Figure 3b and Figure 3d As shown, the longitudinal section of the through hole 110 is similar to a "T" shape.

[0099] like Figure 3a and Figure 3d As shown, the optical structure 13 is in direct contact with the hole wall of the first sub-through hole 1101 .

[0100] like Figure 3b As shown, the optical structure 13 is in direct contact with the hole walls of the first sub-through hole 1101 and the second sub-through hole 1102 .

[0101] Since the aperture of the second sub-through hole 1102 is larger than that of the first sub-through hole 1101, on the one hand, the process alignment accuracy when the optical structure 13 is made by the dispensing process can be reduced; on the other hand, since there is a gap between the LED chip 12 and the hole wall of the first sub-through hole 1101, part of the light emitted by the LED chip 12 and part of the total reflected light 20 may propagate from the gap toward the side of the substrate 10, and the smaller the gap is, the more light 2 can be reflected by the first reflective layer 11, and the higher the light extraction efficiency of the LED chip 12 is. Therefore, when setting, the aperture of the first sub-through hole 1101 can be set smaller than the aperture of the second sub-through hole 1102 to improve the light extraction efficiency of the LED chip 12.

[0102] like Figure 3c and Figure 3e As shown, in this structure, the bearing surface of the substrate 10 is the upper surface of the circuit structure layer 101. The side surface of the LED chip 12 away from the bearing surface of the substrate 10 has a first maximum distance L1 with the bearing surface of the substrate 10.

[0103] A second maximum distance L2 is formed between a surface of the first reflective layer 11 on one side away from the supporting surface of the substrate 10 and the supporting surface of the substrate 10 .

[0104] exist Figure 3c and Figure 3e In, the first maximum spacing L1 and the second maximum spacing L2 are not equal; Figure 3c In, the first maximum spacing L1 is greater than the second maximum spacing L2; Figure 3e In the embodiment, the first maximum distance L1 is smaller than the second maximum distance L2.

[0105] In some embodiments of the present application, Figure 3c As shown, the first maximum spacing L1 is greater than the second maximum spacing L2, that is, the light-emitting surface of the LED chip 12 is higher than the surface of the first reflective layer 11 on the side away from the substrate 10; under this structure, since the LED chip 12 is relatively high, when manufacturing the optical structure 13, it is beneficial to increase the curvature of the light-emitting surface 130 of the optical structure 13, further reduce the number of light rays 2 that undergo total reflection, and improve the light-emitting efficiency of the LED chip 12.

[0106] In some embodiments of the present application, Figure 4a-4c As shown, the first reflective layer 110 includes a first sub-reflective layer 111 and a second sub-reflective layer 112 ; the first sub-through hole 1101 is located on the first sub-reflective layer 111 , and the second sub-through hole 1102 is located on the second sub-reflective layer 112 .

[0107] Since the first sub-reflection layer 111 and the second sub-reflection layer 112 are manufactured separately in batches, the first sub-through hole 1101 and the second sub-through hole 1102 can also be manufactured separately in batches. Especially when manufacturing the first sub-through hole 1101 and the second sub-through hole 1102 with different apertures, manufacturing them separately in batches can reduce the difficulty of manufacturing the through hole 110.

[0108] When the diameter of the first sub-through hole 1101 is smaller than the diameter of the second sub-through hole 1102 , that is, the second sub-through hole 1102 expands outward relative to the first sub-through hole 1101 , the problem of covering the pad due to position deviation of the second sub-reflective layer 112 can also be avoided.

[0109] In some embodiments of the present application, the first sub-reflection layer 111 and the second sub-reflection layer 112 are both made of white ink.

[0110] The first sub-reflection layer 111 and the second sub-reflection layer 112 are manufactured separately in batches, that is, a first layer of white ink (solid-liquid mixed state) is first formed, and a first sub-through hole 1101 is formed through a patterning process after pre-curing, and then the first layer of white ink is completely cured to complete the manufacturing of the first sub-reflection layer 111; then a second layer of white ink is formed on the first sub-reflection layer 111, wherein a part of the second layer of white ink is located in the first sub-through hole 1101, and in the subsequent patterning process for forming the second sub-through hole 1102, the etching liquid will not react with the first sub-reflection layer 111 that has been completely cured, but will only react with the second layer of white ink that has not been completely cured (including removing the uncured white ink located in the first sub-through hole 1101), so as to form the second sub-through hole 1102, so as to complete the manufacturing of the second sub-reflection layer 112.

[0111] Within a certain thickness range, the thicker the white ink layer is, the higher its reflectivity to the light 2 is. However, due to the limitations of the printing process used to prepare the white ink layer, generally only a single layer of white ink with a thickness of less than 30 μm can be formed, and the reflectivity of a single layer of white ink to light is less than 90%; therefore, the first reflective layer 11 can be set to a double-layer ink structure to improve the reflectivity of the first reflective layer 11 to the light 2.

[0112] In some embodiments of the present application, Figure 5a-5d As shown, there is a gap between the hole wall of the through hole 110 and the light-emitting diode chip 12 ; the substrate 10 further includes a second reflective layer 14 ; and the gap exposes at least a portion of the surface of the second reflective layer 14 close to the first reflective layer 11 .

[0113] Among them, Figure 5a and Figure 5bAs shown, the second reflective layer 14 has hollow areas whose number corresponds to the number of through holes 110 ; and the orthographic projection of the through holes 110 on the substrate 10 covers the orthographic projection of the hollow areas on the substrate 10 .

[0114] In some embodiments of the present application, the size of the gap D between the hole wall of the through hole 110 and the light-emitting diode chip 12 is, for example, approximately in the range of 1 um to 5 um.

[0115] In such Figure 5a and Figure 5b In the structure shown, the supporting surface of the base plate 10 is the upper surface of the second reflective layer 14 (the surface on the side away from the substrate 100 ).

[0116] In such Figure 5c and Figure 5d In the structure shown, the bearing surface of the substrate 10 is the upper surface of the circuit structure layer 101 .

[0117] The material of the second reflective layer 14 can be metal or non-metal; the metal material is, for example, silver or aluminum, and the non-metal material is, for example, ink, and the ink is, for example, white ink.

[0118] In some embodiments of the present application, when the material of the second reflective layer 14 is a metal material, it can be formed by magnetron sputtering.

[0119] exist Figure 5a and Figure 5b The second reflective layer 14 is located on the upper side of the circuit structure layer 101. Figure 5c and Figure 5d The second reflective layer 14 is located at the lower side of the circuit structure layer 101. Regardless of whether the second reflective layer 14 is located at the upper side or the lower side of the circuit structure layer 101, when the material of the second reflective layer 14 is a conductive metal, in order to prevent the second reflective layer 14 from affecting the normal operation of the circuit structure layer 101, the second reflective layer 14 needs to be insulated from the circuit structure layer 101. That is to say, the pattern of the second reflective layer 14 and the orthographic projection of the conductive pattern (such as the metal wiring area) in the circuit structure layer 101 on the substrate do not overlap; or a transparent insulating layer needs to be provided between the second reflective layer 14 and the circuit structure layer 101, and the material of the insulating layer can be an organic material or an inorganic material, such as at least one of silicon oxide and silicon nitride. In some embodiments of the present application, such as Figure 5b and Figure 5d As shown, an insulating layer 15 is disposed between the second reflective layer 14 and the circuit structure layer 101 .

[0120] like Figure 5a and Figure 5bAs shown, the second reflective layer 14 is located on the side of the circuit structure layer 101 close to the LED chip 12. During manufacturing, a hollow area needs to be formed on the second reflective layer 14 or on the second reflective layer 14 and the insulating layer 15 to expose the pads in the circuit structure layer 101.

[0121] like Figure 5c and Figure 5d As shown, the second reflective layer 14 is located on the side of the circuit structure layer 101 away from the LED chip 12. When the light 2 propagating toward the substrate 10 is incident on the second reflective layer 14, it will be reflected by the second reflective layer 14 and emitted again.

[0122] There is a gap between the hole wall of the through hole 110 and the light emitting diode chip 12, and part of the light 2 (including the totally reflected light 20) will be incident on the substrate 10 through the gap, and a second reflective layer 14 is provided in the substrate 10. The light 2 incident on the substrate 10 from the gap will be reflected by the second reflective layer 14 and then emitted again. Therefore, the second reflective layer 14 can further improve the light extraction efficiency of the LED chip 12.

[0123] It should be noted that in Figure 5c and Figure 5d In the circuit structure layer 101, although the circuit structure layer 101 is located on the upper side of the second reflective layer 14, there are light-transmitting areas and non-light-transmitting areas in the circuit structure layer 101, wherein the non-light-transmitting area is located in the area of ​​the positive projection of the LED chip 12 on the circuit structure layer, the pad is located in the non-light-transmitting area, and the area between adjacent non-light-transmitting areas is a light-transmitting area. Therefore, the light 2 incident into the substrate 10 from the gap between the LED chip and the hole wall of the through hole 110 can still be reflected by the second reflective layer 14.

[0124] In some embodiments of the present application, Figure 5a and Figure 5b As shown, the second reflective layer 14 is located on one side of the circuit structure layer 101 close to the first reflective layer 11; the second reflective layer 14 includes multiple hollow areas, one of the multiple hollow areas exposes one of the multiple pads in the circuit structure layer 101, and the light-emitting diode chip 12 is electrically connected to the pad.

[0125] When the second reflective layer 14 is located on the side of the circuit structure layer 101 close to the first reflective layer 11, on the one hand, it is convenient to manufacture the second reflective layer 14; on the other hand, the distance between the second reflective layer 14 and the light emitting surface 130 of the optical structure 13 is short, and the distance for the light 2 to be incident on the second reflective layer 14 is short, and the loss is less, which can further improve the light extraction rate of the LED chip 12.

[0126] In some embodiments of the present application, Figure 6As shown, the second reflective layer 14 includes a first sub-transparent insulating layer 141 , a metal reflective layer 142 and a second sub-transparent insulating layer 143 which are sequentially stacked along the thickness direction of the substrate 10 .

[0127] In this structure, the second reflective layer 14 is an insulating structure as a whole, and can be located on the upper side or the lower side of the circuit structure layer 101. Moreover, since a metal reflective layer 142 with a higher reflectivity is sandwiched between the two insulating layers, the light extraction efficiency of the LED chip 12 can be further improved.

[0128] In some embodiments of the present application, Figure 7 As shown, the second reflective layer 14 is located on the side of the circuit structure layer 101 away from the first reflective layer 11; the circuit structure layer 101 has a plurality of metal wiring areas 1010, and a light-transmitting area 1011 located between two adjacent metal wiring areas 1010. The circuit structure layer 101 includes a pad disposed on the metal wiring area 1010; the light-transmitting area 1011 is used to transmit part of the light 2 emitted by the light emitting diode chip 12 and reflected by the second reflective layer 14, and the metal wiring area 1010 is a non-light-transmitting area.

[0129] The light 2 is incident on the second reflective layer 14 from the light-transmitting area 1011 , and is reflected by the second reflective layer 14 and then emitted again, so the light extraction efficiency of the LED chip is relatively high.

[0130] In some embodiments of the present application, Figure 8 As shown, the backplane 1 further includes an adhesive layer 16 , which is located on a side of the first reflective layer 11 facing the substrate 10 and is used to adhere the first reflective layer 11 to the substrate 10 .

[0131] The material of the adhesive layer 16 is, for example, acrylic glue.

[0132] In the case where the first reflective layer 11 is a reflective sheet, the reflective sheet needs to be bonded to the substrate 10 , and therefore an adhesive layer 16 needs to be provided to fix the first reflective layer 11 and the substrate 10 .

[0133] In some embodiments of the present application, Figure 1a As shown, the material constituting the optical structure 13 includes a transparent colloid material and a light conversion material mixed with the transparent colloid material, and the light conversion material is used to convert the color of the light 2 emitted by the light emitting diode chip 12 .

[0134] The transparent colloid material is, for example, packaging glue, and the light conversion material is, for example, phosphor, quantum dot material, perovskite material, etc.

[0135] In some embodiments of the present application, when the light emitting diode chip 12 emits blue light, the blue light can be converted into white light or red light or filtered light by providing a light conversion material in the optical structure 13 .

[0136] Adding light conversion material to the material of the optical structure 13 can not only optimize the structure of the backplane 1 but also reduce the cost of the backplane 1 .

[0137] In some embodiments of the present application, Figure 9a As shown, the back plate 1 further includes a hydrophobic layer 110 , which is located on a side of the first reflective layer 11 away from the substrate 10 , and the hydrophobic layer 110 includes a plurality of hollow areas, and one optical structure 13 covers one hollow area.

[0138] The material of the hydrophobic layer is a hydrophobic material, for example, a fluorinated polymer such as fluorinated polyethylene, fluorocarbon wax, etc.

[0139] The hydrophobic layer can prevent adjacent optical structures 13 from sticking together, thus facilitating the molding of the optical structure 13 .

[0140] In some embodiments of the present application, Figure 9b and Fig.9c As shown, when the optical structure 13 does not include a light conversion material, the backplane 1 further includes a light conversion layer 17 , and the light conversion layer 17 is located on a side of the optical structure 13 away from the substrate 10 .

[0141] The light conversion layer 17 is used to convert the light 2 of the LED chip 12 emitting at least one of the three primary colors into white light.

[0142] In some embodiments of the present application, the light conversion layer 17 can convert blue light into white light.

[0143] The light color of the LED chip 12 is converted by the light conversion layer 17 , and the conversion efficiency and conversion effect are good, which can improve the quality of the light 2 emitted by the back plate 1 and ensure the display effect of the display panel.

[0144] In some embodiments of the present application, the backplane 1 is, for example, a backlight module. Along the light emitting direction of the backlight module, the backlight module includes, for example: a driving backplane, a light emitting diode layer, an optical structure layer, a lower diffusion film, a quantum dot film, an upper diffusion film, and a prism film. The driving backplane is a substrate 10; the light emitting diode layer includes a plurality of LED chips 12; the optical structure layer includes a plurality of optical structures 13; and the quantum dot film is a light conversion layer 17. The prism film and the upper diffusion film can make the light emitting of the backlight module more uniform and improve the light emitting effect.

[0145] In some embodiments of the present application, the LED chip 12 in the backplane 1 can be directly used as a pixel for display, that is, the backplane 1 can be a display backplane, serving as a core component in a Mini LED display device and a Micro LED display device.

[0146] The embodiment of the present invention further provides a method for preparing a backplane 1, wherein the backplane 1 includes a substrate 10, the substrate 10 includes a circuit structure layer 101, and the circuit structure layer 101 includes a plurality of pads.

[0147] like Fig.10a As shown, the method for preparing the back plate 1 includes:

[0148] S1, such as Fig.10b As shown, a first ink film is formed on the supporting surface of the substrate 10 , and a plurality of through holes 110 are formed on the first ink film to form a first reflective layer 11 .

[0149] The material of the first ink film is white ink, and the first ink film can be formed by, for example, screen printing or coating.

[0150] The plurality of through holes 110 may be formed on the first ink film by, for example, a patterning process.

[0151] S2, such as Fig.10c As shown, on a substrate 10 formed with a first reflective layer 11, a plurality of light emitting diode chips 12 are electrically connected to a plurality of pads in a one-to-one correspondence.

[0152] In some embodiments of the present application, the LED chip is a blue light LED chip 12 .

[0153] S3, such as Figure 1a As shown, on the side of the multiple LED chips 12 away from the substrate 10, multiple optical structures 13 are formed by a dispensing process, and the light-emitting surface 130 of the optical structure 13 is a curved surface; one optical structure 13 among the multiple optical structures 13 covers the light-emitting surface of one LED chip 12 among the multiple LED chips 12 and is in direct contact with the light-emitting surface of the LED chip 12.

[0154] In some embodiments of the present application, the optical structure 13 includes, for example, a transparent colloid material.

[0155] In some embodiments of the present application, the material of the optical structure 13 may include a fumed silica material in addition to the transparent colloid material. The fumed silica material can increase the viscosity of the transparent colloid material, which is beneficial to the molding of the optical structure 13 .

[0156] In some other embodiments, the optical structure 13 may include a light conversion material in addition to the transparent colloid material.

[0157] The method for preparing the backplane 1 has the same beneficial effects as the above-mentioned backplane 1, so it will not be described in detail.

[0158] In some embodiments of the present application, forming a first ink film includes:

[0159] S10, such as Fig.11a As shown, a first sub-ink film is formed on the bearing surface of the substrate 10 , and a first sub-through hole 1101 is formed on the first sub-ink film.

[0160] S11, such as Fig.11b As shown, a second sub-ink film is formed on the first sub-ink film, and a second sub-through hole 1102 is formed on the second sub-ink film, and the second sub-through hole 1102 is connected to the first sub-through hole 1101, and the first sub-through hole 1101 and the second sub-through hole 1102 constitute a through hole 110.

[0161] In some embodiments of the present application, the material and manufacturing process of the second sub-ink film are the same as those of the first sub-ink film, and the manufacturing process of the second sub-through hole 1102 is the same as that of the first sub-through hole 1101 .

[0162] In some embodiments of the present application, a diameter of the first sub-through hole 1101 is smaller than a diameter of the second sub-through hole 1102 .

[0163] The second sub-through hole 1102 has a larger diameter, which is beneficial to reducing the alignment accuracy of the dispensing process, and the double-layer ink structure is beneficial to the molding of the optical structure 13 and improving the reflectivity of the first reflective layer 11.

[0164] In some embodiments of the present application, before forming the first reflective layer 11, the method for preparing the backplane 1 further includes:

[0165] like Fig.12a As shown, a second ink film is formed on the bearing surface of the substrate 10 , and a plurality of hollow areas are formed on the second ink film to expose the pads in the circuit structure layer 101 , so as to form a second reflective layer 14 .

[0166] The material of the second ink film is, for example, the same as that of the first ink film.

[0167] In some embodiments of the present application, before forming the first reflective layer 11, the method for preparing the backplane 1 further includes:

[0168] S01, such as Figure 12b As shown, a first sub-transparent insulating layer 141 is formed on the supporting surface of the substrate 10 .

[0169] In some embodiments of the present application, the bearing surface of the substrate 10 is the upper surface of the circuit structure layer 101 .

[0170] In some embodiments of the present application, the material of the first sub-transparent insulating layer 141 is, for example, polyimide or plastic.

[0171] The pad needs to be exposed when forming the first sub-transparent insulating layer 141 .

[0172] S02, such as Fig.12c As shown, a metal reflective layer 142 is formed on the first sub-transparent insulating layer 141 .

[0173] In some embodiments of the present application, the material of the metal reflective layer 142 is, for example, aluminum.

[0174] S03, such as Fig.12d As shown, a second sub-transparent insulating layer 143 is formed on the metal reflective layer; the first sub-transparent insulating layer 141 , the metal reflective layer 142 and the second sub-transparent insulating layer 143 constitute the second reflective layer 14 .

[0175] In some embodiments of the present application, the material of the second sub-transparent insulating layer 143 is, for example, polyimide or plastic.

[0176] The second reflective layer 14 is manufactured on the supporting surface of the substrate 10 , and the manufacturing process is relatively simple. In addition, the paths of the total reflected light 20 and other light 2 propagating toward the side of the substrate 10 incident on the second reflective layer 14 are shorter, and the loss is less.

[0177] The embodiment of the present invention further provides a method for preparing a backplane 1, wherein the backplane 1 includes a substrate 10, the substrate 10 includes a circuit structure layer 101, and the circuit structure layer 101 includes a plurality of pads.

[0178] like Fig.13a As shown, the method for preparing the back plate 1 includes:

[0179] S100, such as Fig.13b As shown, a plurality of light emitting diode chips 12 are electrically connected to a plurality of bonding pads in a one-to-one correspondence.

[0180] The circuit structure layer 101 includes a metal wiring area 1010 and a light-transmitting area 1011. The pad is located in the metal wiring area 1010, but in the Fig.13b Not indicated in the.

[0181] S200, such as Fig.13c As shown, an adhesive layer 16 is formed on the non-functional surface of the reflective sheet, and a first protective film 18 is attached to the adhesive layer 16 .

[0182] The reflectivity of the functional surface of the reflector is greater than the reflectivity of the non-functional surface of the reflector, so as to distinguish the functional surface from the non-functional surface of the reflector.

[0183] The thickness of the adhesive layer 16 is, for example, approximately in the range of 10 μm (micrometers) to 50 μm, and the peeling force between the adhesive layer 16 and the substrate 10 is, for example, greater than 50 gf (gram-force / inch).

[0184] In this structure, the reflective sheet is used as the first reflective layer 11, wherein the reflectivity of the functional surface of the reflective sheet to the light 2 can reach 98%, which is a relatively high reflectivity.

[0185] S300, such as Fig.13d As shown, a plurality of through holes 110 are formed on the reflective sheet bonded to the first protective film 18 , and the through holes 110 penetrate the reflective sheet, the adhesive layer 16 and the first protective film 18 .

[0186] The through hole 110 may be formed by, for example, laser drilling, mechanical tool cutting, chemical etching, or the like.

[0187] S400, such as Fig.13e As shown, the first protective film 18 is torn off, and the reflective sheet is attached to the supporting surface of the substrate 10 through the adhesive layer 16 , and the plurality of light-emitting diode chips 12 are located in the plurality of through holes 110 in a one-to-one correspondence.

[0188] When the reflective sheet is attached to the substrate 10, the reflective sheet and the substrate 10 need to be aligned so that the through holes 110 on the reflective sheet correspond one-to-one with the pads on the substrate 10; the alignment can be performed, for example, by manual jig alignment or automatic optical detection equipment (an automatic jig).

[0189] The reflective sheet and the substrate 10 may be attached to each other by pressing with a jig or by using a sealed high-pressure chamber, wherein the jig may be a roller, and the sealed high-pressure chamber may attach the reflective sheet to the substrate 10 by using air pressure.

[0190] like Fig.13e As shown in FIG. 1 , when the reflective sheet is attached to the substrate 10 by pressing with a roller, since the light-emitting surface of the LED chip 12 is higher than the upper surface of the reflective sheet (the surface on the side away from the substrate 10), directly using the roller may damage the LED chip 12, so a second protective film needs to be attached to the functional surface of the reflective sheet. In some embodiments of the present application, the second protective film is a release paper. The structure after attaching the second protective film to the reflective sheet is as shown in FIG. Fig.13f As shown, the total thickness of the second protective film 19, the reflective layer 11 and the adhesive layer 16 is greater than or equal to the height of the LED chip 12. The specific height difference should take into account the compression generated when pressing and attaching to ensure that the LED chip 12 is not crushed. In some embodiments of the present application, the height difference between the total thickness of the second protective film 19, the reflective layer 11 and the adhesive layer 16 and the height of the LED chip 12 is as small as possible, which is conducive to the light emission around the LED chip. Figure 13gAs shown, after the reflective sheet with the second protective film 19 is aligned with the substrate 10, ensure that the upper surface of the second protective film 19 and the upper surface of the LED chip 12 are higher than the upper surface of the LED chip 12 or are flush with the upper surface of the LED chip 12, and then use a roller to press to make the reflective sheet and the substrate 10 tightly attached; after pressing is completed, tear off the second protective film 19.

[0191] It should be noted that when the upper surface of the reflective sheet is higher than or flush with the light emitting surface of the LED chip 12 , a roller can be used to press directly, and in this structure, the second protective film 19 does not need to be attached.

[0192] S500, such as Figure 8 As shown, on the side of the multiple LEDs away from the substrate 10, multiple optical structures 13 are formed by a dispensing process, and the light-emitting surface 130 of the optical structure 13 is a curved surface; one optical structure 13 among the multiple optical structures 13 covers the light-emitting surface of one LED chip 12 among the multiple LED chips 12 and is in direct contact with the light-emitting surface of the LED chip 12.

[0193] The method for preparing the backplane 1 has the same beneficial effects as the backplane 1 described above, and therefore will not be described in detail.

[0194] In some embodiments of the present application, a plurality of optical structures 13 are formed by a dispensing process, including:

[0195] The transparent colloid material and the light conversion material are mixed and a plurality of optical structures 13 are formed by a dispensing process; wherein the light conversion material is used to convert the color of the light 2 emitted by the light emitting diode chip 12 .

[0196] In some embodiments of the present application, the light conversion material is, for example, a quantum dot material, which has a high light conversion efficiency.

[0197] With this structure, the structure of the back plate 1 can be reduced, thereby reducing production costs.

[0198] Those skilled in the art should understand that the light output efficiency of the LED chip 12 = the light output of the back plate / the light output of all LED chips.

[0199] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A backplane, characterized in that: include: A substrate, the substrate comprising a circuit structure layer, the circuit structure layer having a plurality of metal wiring areas and a light-transmitting area between two adjacent metal wiring areas; the circuit structure layer comprising a pad disposed in the metal wiring area; A first reflective layer, wherein the first reflective layer is disposed on the bearing surface of the substrate; the first reflective layer comprises a plurality of through holes disposed at intervals; A plurality of light-emitting diode chips; one of the plurality of light-emitting diode chips is located in one of the plurality of through holes, and a gap is provided between the hole wall of the through hole and the light-emitting diode chip; the light-emitting diode chip is electrically connected to the circuit structure layer; the circuit structure layer is used to drive the light-emitting diode chip to emit light; A second reflective layer is disposed on a side of the circuit structure layer away from the first reflective layer, and an orthographic projection of the gap on the substrate at least partially overlaps with an orthographic projection of the second reflective layer on the substrate; The light-transmitting area is used to transmit part of the light emitted by the light-emitting diode chip and reflected by the second reflective layer; A plurality of optical structures, wherein the light emitting surfaces of the optical structures are curved surfaces; an optical structure among the plurality of optical structures covers the light emitting surface of one of the plurality of light emitting diode chips and is in direct contact with the light emitting surface of the light emitting diode chip.

2. The back plate according to claim 1, characterized in that: The through hole comprises a first sub-through hole and a second sub-through hole which are connected and sequentially away from the substrate; Wherein, the aperture of the first sub-through hole is smaller than the aperture of the second sub-through hole; The optical structure is in direct contact with at least a hole wall of the first sub-through hole.

3. The back plate according to claim 2, characterized in that: A first maximum distance is formed between a side surface of the light emitting diode chip away from the carrying surface of the substrate and the carrying surface of the substrate; A side surface of the first reflective layer away from the bearing surface of the substrate has a second maximum distance from the bearing surface of the substrate; The first maximum spacing is greater than the second maximum spacing.

4. The back plate according to claim 2, characterized in that: The first reflective layer includes a first sub-reflective layer and a second sub-reflective layer; the first sub-through hole is located on the first sub-reflective layer, and the second sub-through hole is located on the second sub-reflective layer.

5. The back plate according to claim 1, characterized in that: The back plate further includes an adhesive layer, which is located on a side of the first reflective layer close to the substrate and is used to adhere the first reflective layer to the substrate.

6. The back plate according to claim 1, characterized in that: The materials constituting the optical structure include a transparent colloid material and a light conversion material mixed with the transparent colloid material, and the light conversion material is used to convert the color of the light emitted by the light emitting diode chip.

7. The back plate according to claim 1, characterized in that: The backplane further comprises a light conversion layer, and the light conversion layer is located on a side of the optical structure away from the substrate.

8. A display device, characterized in that: It comprises the backplane and display panel as described in any one of claims 1 to 7.

9. A method for preparing a backplane, characterized in that: The method for preparing the backplane comprises: forming a second ink film on the substrate, and forming a plurality of hollow areas on the second ink film to form a second reflective layer; Alternatively, a first sub-transparent insulating layer is formed on the substrate; forming a metal reflective layer on the first sub-transparent insulating layer; forming a second sub-transparent insulating layer on the metal reflective layer; the first sub-transparent insulating layer, the metal reflective layer and the second sub-transparent insulating layer constitute a second reflective layer; forming a circuit structure layer on the second reflective layer, wherein the circuit structure layer comprises a plurality of pads; forming a first ink film on the circuit structure layer, and forming a plurality of through holes on the first ink film to expose the pads in the circuit structure layer, so as to form a first reflective layer; Electrically connecting a plurality of light-emitting diode chips to a plurality of the pads in a one-to-one correspondence; wherein a gap is provided between the light-emitting diode chip and a side wall of the through hole, and an orthographic projection of the gap on the substrate at least partially overlaps with an orthographic projection of the second reflective layer on the substrate; On a side of the multiple LED chips away from the substrate, multiple optical structures are formed by a dispensing process, and the light-emitting surfaces of the optical structures are curved surfaces; one optical structure among the multiple optical structures covers the light-emitting surface of one LED chip among the multiple LED chips and is in direct contact with the light-emitting surface of the LED chip.

10. The method for preparing a back sheet according to claim 9, characterized in that: Forming a first ink film includes: forming a first sub-ink film on the bearing surface of the substrate, and forming a first sub-through hole on the first sub-ink film; A second sub-ink film is formed on the first sub-ink film, and a second sub-through hole is formed on the second sub-ink film, and the second sub-through hole is connected to the first sub-through hole, and the first sub-through hole and the second sub-through hole constitute the through hole.

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