Luminescent substrate and preparation method thereof

Abstract

The present invention relates to a light-emitting substrate and a preparation method thereof. The light-emitting substrate comprises a substrate, on which a plurality of light-emitting devices are arranged at intervals; a first light-shielding structure is arranged at the gaps between the light-emitting devices, and the first light-shielding structure is used to shield the light emitted laterally by the light-emitting devices; the first light-shielding structure and the light-emitting devices do not overlap in the target light-emitting direction of the light-emitting devices, or the overlapping area between the first light-shielding structure and the light-emitting devices in the target light-emitting direction of the light-emitting devices is less than a set value. Since the first light-shielding structure is arranged at the gaps between the light-emitting devices, the light emitted laterally by the light-emitting devices can be shielded, and this part of the light can be prevented from irradiating other light-emitting devices to generate light crosstalk. In addition, the light emitted by the light-emitting devices in the target light-emitting direction will not be shielded or completely shielded, thereby improving or eliminating the adverse effects on the light efficiency of the light-emitting devices, thereby improving the light-emitting effect of the light-emitting surface of the light-emitting substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of light-emitting devices, and in particular to a light-emitting substrate and a preparation method thereof. Background Art

[0002] Light-emitting diodes (LEDs) are currently the mainstream light-emitting devices with a wide range of uses. For example, LEDs can be used as light-emitting devices in the backlight source of liquid crystal display devices, and smaller LED devices, such as Micro LEDs and Mini LEDs, can also be used directly for display.

[0003] In the devices currently using LEDs as light-emitting devices, multiple LED arrays are generally arranged. When the gaps between multiple LEDs are small, the light emitted to the side by each LED will be mixed with the light emitted by other LEDs, thereby causing obvious light crosstalk. In order to solve this problem, the prior art provides a layer of black glue, which fills the gaps between the LEDs and blocks the transmission of the light emitted to the side by the LEDs, thereby avoiding light crosstalk. However, this method also has other problems. When the black glue is formed, the black glue will not only fill the gaps between the LEDs, but also cover the LEDs. The black glue covering the LED will reduce the light emitted by the LED in the target light-emitting direction, affecting the light efficiency of the LED as a light-emitting device. Summary of the invention

[0004] The present invention provides a light-emitting substrate and a preparation method thereof, so as to solve the technical problem of affecting the light efficiency of the light-emitting device in the above-mentioned prior art.

[0005] The light-emitting substrate provided by the present invention includes a substrate, on which a plurality of light-emitting devices are arranged at intervals; a first shading structure is arranged in the gaps between the light-emitting devices, and the first shading structure is used to block the light emitted laterally by the light-emitting devices; the first shading structure and the light-emitting devices do not overlap in the target light-emitting direction of the light-emitting devices, or the overlapping area between the first shading structure and the light-emitting devices in the target light-emitting direction of the light-emitting devices is less than a set value.

[0006] Wherein, the material of the first light shielding structure is black matrix or metal.

[0007] Wherein, the material of the first light-shielding structure is one of molybdenum, copper and aluminum.

[0008] Among them, the first light shading structure includes a bottom, a side and a top; the bottom of the first light shading structure faces the substrate; the side of the first light shading structure faces the light emitting device and surrounds the light emitting device; the top of the first light shading structure is flush with the top of the light emitting device or higher than the top of the light emitting device.

[0009] Wherein, the light emitting device is an LED.

[0010] Wherein, the first light-shielding structure is a single-layer or multi-layer structure.

[0011] The light-emitting substrate further comprises a second shading structure, which is located at the top side of the light-emitting device and away from the top of the light-emitting device; the projection of the second shading structure on the surface where the light-emitting device is located is located in the gap between the light-emitting devices.

[0012] The light-emitting substrate has a multi-layer second light-shielding structure, and the multi-layer second light-shielding structure is sequentially arranged at intervals in the target light-emitting direction of the light-emitting device.

[0013] Wherein, the material of the second light shielding structure is black matrix or metal.

[0014] Wherein, the material of the second light-shielding structure is one of molybdenum, copper and aluminum.

[0015] The light-emitting substrate includes a light-guiding column, the refractive index of the material of the light-guiding column is higher than a first set value; and the light-guiding column corresponds to the light-emitting device in a target light-emitting direction of the light-emitting device.

[0016] There is an inter-column structure between adjacent light-guiding columns, and the refractive index of the inter-column structure is lower than a second set value, and the second set value is smaller than the first set value.

[0017] Wherein, the refractive index of the light guide column is between 1.8 and 2.5.

[0018] Wherein, the refractive index of the inter-column structure is between 1 and 1.5.

[0019] The light-emitting substrate includes one or more planarization layers covering the light-emitting device, and the light transmittance of each planarization layer covering the light-emitting device is greater than 90%.

[0020] The present invention provides a method for preparing a light-emitting substrate, which comprises:

[0021] Forming a first light-shielding material layer: forming a first light-shielding material layer covering the light-emitting devices and gaps between the light-emitting devices on the substrate having the light-emitting devices;

[0022] Forming a first light-shielding structure: removing the first light-shielding material layer pattern covering the light-emitting device in at least a partial area corresponding to the light-emitting device, so as to expose at least a partial area of ​​the light-emitting device.

[0023] The material of the first light-shielding material layer is a black matrix; when removing the pattern of the first light-shielding material layer covering the light-emitting device, the entire first light-shielding material layer is etched so that the first light-shielding material layer is thinned to a height corresponding to the top of the light-emitting device.

[0024] When removing the pattern of the first light-shielding material layer covering the light-emitting device, the pattern of the first light-shielding material layer covering the light-emitting device is removed by etching through a mask exposure and etching process.

[0025] Wherein, the first light-shielding material layer is a metal layer; and the step of forming the first light-shielding structure further comprises:

[0026] Before removing the pattern of the first light shielding material layer covering the light emitting device through a mask exposure and etching process, forming a planarization layer;

[0027] The planarization layer is thinned to expose the pattern of the first light shielding material layer covering the light emitting device.

[0028] Wherein, the preparation method of the light-emitting substrate further comprises:

[0029] A patterning process is performed to form a second light-shielding material layer, wherein the second light-shielding material layer is formed and overlapped on the retained first light-shielding material layer.

[0030] Wherein, the preparation method of the light-emitting substrate further comprises:

[0031] Forming a second light-shielding structure: forming a planarization layer, and forming a light-shielding pattern on the planarization layer in an area corresponding to the gap between the light-emitting devices, wherein the light-shielding pattern is a second light-shielding structure.

[0032] Wherein, the preparation method of the light-emitting substrate further comprises:

[0033] The step of forming the second light shielding structure is repeated to form multiple layers of the second light shielding structure on the light emitting substrate.

[0034] Wherein, the preparation method of the light-emitting substrate further comprises:

[0035] A light guide column is formed in a target light emitting direction of the light emitting device, and the refractive index of the material forming the light guide column is greater than a first set value.

[0036] Wherein, the preparation method of the light-emitting substrate further comprises:

[0037] After forming the light guide column, a layer of filling material is deposited, and the deposited filling material fills the gap between adjacent light guide columns. The refractive index of the filled material is less than a second set value, and the second set value is less than the first set value.

[0038] Wherein, the preparation method of the light-emitting substrate further comprises:

[0039] Remove the filling material covering the light guide.

[0040] The present invention provides a light-using device, which includes the above-mentioned light-emitting substrate.

[0041] Wherein, the light-using device is a backlight source, a display device or a 3D printing device.

[0042] The above-mentioned light-emitting substrate and the preparation method thereof provided by the embodiment of the present invention have the following advantages compared with the prior art:

[0043] The light-emitting substrate provided by the present invention has a first light-shielding structure disposed at the gap between the light-emitting devices, that is, at the lateral position of the light-emitting devices, so that the light emitted laterally by the light-emitting devices can be shielded to prevent the light from being irradiated to other light-emitting devices and causing light crosstalk. Moreover, in the target light-emitting direction of the light-emitting devices, the first light-shielding structure does not overlap with the light-emitting devices, so the first light-shielding structure will not shield the light emitted by the light-emitting devices in the target light-emitting direction, and will not affect the light efficiency of the light-emitting devices, thereby ensuring that the light-emitting devices can emit sufficient light in the target light-emitting direction with sufficient brightness, thereby improving the light-emitting effect of the light-emitting surface of the light-emitting substrate.

[0044] The method for preparing a light-emitting substrate provided by the present invention has a light-emitting substrate prepared therefrom that is the same as the above-mentioned light-emitting substrate and has the same beneficial effects as the above-mentioned light-emitting substrate, which will not be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0046] 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] Figure 1 It is a structural schematic diagram of a light-emitting substrate according to an embodiment of the present invention;

[0048] Figure 2 for Figure 1 A schematic diagram of the structure of the light-emitting substrate in a top view;

[0049] Figure 3 A schematic diagram of a light-emitting device of a light-emitting substrate emitting light laterally;

[0050] Figure 4 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0051] Figure 5 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0052] Figure 6 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0053] Figure 7 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0054] Figure 8 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0055] Fig. 9 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0056] Fig.10 is a schematic structural diagram of a light-emitting substrate according to another embodiment of the present invention;

[0057] Fig.11 is a process flow chart of a method for preparing a light-emitting substrate of the present invention;

[0058] Fig.12 is a structural schematic diagram of a substrate having a light-emitting device;

[0059] Fig.13 is a schematic diagram of forming a first light-shielding material layer in one embodiment;

[0060] Fig.14 is a schematic diagram of forming a first light-shielding material layer in another embodiment;

[0061] Fig.15 A schematic diagram of removing a first light-shielding material layer that blocks a light-emitting device in one embodiment;

[0062] Fig.16 It is a schematic diagram of removing the first light-shielding material layer that blocks the light-emitting device in another embodiment;

[0063] Fig.17 A process flow chart of removing a first light-shielding material layer that blocks a light-emitting device in another embodiment;

[0064] Fig.18 is a schematic diagram of forming a planarization layer;

[0065] Fig.19 is a schematic diagram of thinning the planarization layer;

[0066] Fig. 20 A schematic diagram of removing the first light-shielding material layer that blocks the light-emitting device;

[0067] Fig.21 is a schematic diagram of forming a second light-shielding material layer in one embodiment;

[0068] Fig. 22 is a schematic diagram of forming a second light shielding structure in one embodiment;

[0069] Fig.23 is a schematic diagram of forming a planarization layer on the second light shielding structure;

[0070] Fig.24 A schematic diagram of a structure for forming a light guide column in an embodiment;

[0071] Fig.25 A schematic diagram of forming an inter-column structure in one embodiment;

[0072] Fig.26 It is a schematic diagram of removing the portion of the inter-column structure located above the light guide column in an embodiment.

[0073] In the figure:

[0074] 10-Substrate;

[0075] 20-light emitting device;

[0076] 30-first light-shielding structure; 301-first light-shielding material layer; 302-second light-shielding material layer;

[0077] 40- second light shielding structure;

[0078] 50-light guide column; 51-inter-column structure;

[0079] 60 - planarization layer; 60a - first planarization layer; 60b - second planarization layer; 60c - third planarization layer. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0081] The embodiments of the light-emitting substrate and the preparation method thereof provided by the present invention are described below in conjunction with the accompanying drawings.

[0082] In one embodiment of the light emitting substrate of the present invention, see Figure 1 and Figure 2The light-emitting substrate includes a substrate 10, on which a plurality of light-emitting devices 20 are arranged at intervals. The light-emitting device 20 may be a light-emitting diode (LED); further, when LED is used as the light-emitting device 20, a miniaturized LED device may be selected, such as Mini LED (LED chip size is 100 to 300 microns) or Micro LED (LED chip size is less than 100 microns). Of course, LEDs of ordinary size (LED chip size is greater than 300 microns) may also be used as the light-emitting device 20, and other types of light-emitting devices other than LED may also be selected.

[0083] As for the light emitting device 20 disposed on the substrate 10, basically, it can emit light in a target light emitting direction, which is the direction in which the light emitting device 20 is required to emit light by the light emitting substrate, generally the light emitting surface of the light emitting substrate. Figure 1 As shown in the example, the light emitting surface of the light emitting substrate is Figure 1 In the upper direction, the light-emitting substrate requires the light-emitting device 20 to emit light upward to form light emitted from the light-emitting surface. Therefore, Figure 1 The upper direction in the figure is the target light emitting direction of the light emitting device 20. In practice, in many cases, a light emitting device 20 can emit light in addition to the target light emitting direction, and also emit light in the side direction, such as Figure 3 As shown, the light is irradiated onto other light emitting devices 20 or onto target light emitting areas (areas corresponding to the light emitting devices 20 in the target light emitting direction) of other light emitting devices 20, thereby generating light crosstalk.

[0084] See 1 and Figure 2 , a first light shielding structure 30 is provided at the gap between the light emitting devices 20, and the first light shielding structure 30 is used to shield the light emitted laterally by the light emitting devices 20. In addition, the first light shielding structure 30 and the light emitting devices 20 do not overlap in the target light emitting direction of the light emitting devices 20. Specifically, the first light shielding structure 30 includes a bottom, a side, and a top. Figure 1 As shown in FIG. 1 , the bottom of the first light shielding structure 30 faces the substrate 10. The side of the first light shielding structure 30 faces the light emitting device 20 and surrounds the light emitting device 20. Figure 2 In the example shown, the first light shielding structure 30 has a corresponding opening at the position of each light emitting device 20, and the light emitting device 20 is located in the opening. The first light shielding structure 30 surrounds the light emitting device 20 at the side of the opening. The top of the first light shielding structure 30 is flush with the top of the light emitting device 20 or higher than the top of the light emitting device 20, such as Figure 1 , Figure 4 and Figure 5 Example shown.

[0085] Specifically, the material of the first light shielding structure 30 can be a black matrix or a metal, and the black matrix and the metal can play a good role in blocking light transmission. When the first light shielding structure 30 is formed with a black matrix or a metal material, a material layer of the black matrix or the metal is usually formed by deposition or sputtering, and the black matrix or the metal material formed in this way will also cover the light-emitting device 20 at the same time. When preparing the light-emitting substrate of this embodiment, after performing the above-mentioned process steps, the black matrix or the metal material covering the light-emitting device 20 can be removed by thinning or etching, so that the formed first light shielding structure 30 does not overlap with the light-emitting device 20 in the target light emitting direction of the light-emitting device 20 and shield the light-emitting device 20.

[0086] Specifically, when metal is selected to form the first light shielding structure 30, molybdenum, copper, aluminum and other metal materials can be selected. In addition, metal with relatively high reflectivity can be preferred. The first light shielding structure 30 formed by the material with high reflectivity can not only block the transmission of light emitted to the side by the light emitting device 20, but also reflect the light as much as possible to the light emitting device 20, so that at least part of the light can be emitted from the target light emitting direction of the light emitting device 20, thereby increasing the amount of light emitted from the target light emitting direction of the light emitting device 20, thereby further improving the light emitting effect.

[0087] The first light shielding structure 30 is arranged at the gap between the light emitting devices 20, that is, at the lateral position of the light emitting device 20, so that the light emitted by the light emitting device 20 to the lateral direction can be shielded to prevent the light from being irradiated to other light emitting devices 20 and generating light crosstalk. In addition, in the target light emitting direction of the light emitting device 20, the first light shielding structure 30 and the light emitting device 20 do not overlap, so the first light shielding structure 30 will not shield the light emitted by the light emitting device 20 to the target light emitting direction, and will not affect the light effect of the light emitting device 20, ensuring that the light emitting device 20 can emit enough light to the target light emitting direction with enough brightness, thereby improving the light emitting effect of the light emitting surface of the light emitting substrate.

[0088] In another embodiment of the light-emitting substrate, the first shading structure 30 and the light-emitting device 20 may also overlap in the target light-emitting direction of the light-emitting device 20 based on possible process errors or intentional settings, etc., as long as the overlapping area of ​​the first shading structure 30 and the light-emitting device 20 in the target light-emitting direction of the light-emitting device 20 is less than the set value. By setting the set value to a suitable size, the area of ​​the first shading structure 30 overlapping with the light-emitting device 20 can be controlled to block the light-emitting device 20 without significantly affecting the light emission of the light-emitting device 20 in the target light-emitting direction, so that it is within an acceptable range, and the requirements of various performance parameters of the light-emitting substrate are achieved and met. Specifically, for the set value, its specific type can be the absolute value of the area of ​​the overlapping area between the first shading structure 30 and the light-emitting device 20 (for example, the area of ​​the overlapping area between the first shading structure 30 and the light-emitting device 20 does not exceed 100 square microns), or it can be the size of the overlapping area of ​​the two relative to the light-emitting device 20 (for example, the overlapping area of ​​the first shading structure 30 and the light-emitting device 20 accounts for no more than 10% of the light-emitting device 20).

[0089] In one embodiment of the light emitting substrate, Figure 4 or Figure 5 As shown, the first light shielding structure 30 is flush with the top of the light emitting device 20 . Figure 4 In the structure shown, the material of the first light shielding structure 30 may be a black matrix; Figure 5 In the structure shown, the material of the first light shielding structure 30 can be metal. When the first light shielding structure 30 is flush with the top of the light emitting device 20, it can effectively shield the light emitted laterally from the side of the light emitting device 20, and effectively improve the crosstalk of light.

[0090] In another embodiment of the light emitting substrate, Figure 1 and Figure 6 As shown, the first shading structure 30 can also be higher than the top of the light emitting device 20. In the case where the first shading structure 30 is higher than the top of the light emitting device 20, the first shading structure 30 can not only effectively shield the light emitted laterally from the side of the light emitting device 20; for the light emitted from the side of the light emitting device 20 facing the target light emitting direction and inclined to the side, when a part of it is irradiated on the first shading structure 30, the first shading structure 30 can of course block and continue to be emitted obliquely to the side, so as to achieve shielding of this part of the light; in essence, in this case, the part of the first shading structure 30 that is higher than the top of the light emitting device 20 plays the role and effect of collimating the light emitted by the light emitting device 20 toward the target light emitting direction, which can further improve the crosstalk of light.

[0091] In one embodiment of the light emitting substrate, the first light shielding structure 30 may be a single-layer structure, such as Figure 4 or Figure 6 As shown; or a multi-layer structure, such as Figure 1 As shown. When the first light-shielding structure 30 is a single-layer structure, for example, when the material of the first light-shielding structure 30 is a black matrix, the black matrix can be coated and cured in multiple times, and the black matrix formed in this way is regarded as a single-layer structure. When the first light-shielding structure 30 is a multi-layer structure, for example, it can include a first light-shielding material layer 301 and a second light-shielding material layer 302; the material of each layer of the structure can be different, or it can be the same but formed in sequence through different process steps (with other process steps in between) and superimposed together.

[0092] In one embodiment of the light emitting substrate, Figure 7 As shown, the light-emitting substrate further includes a second light-shielding structure 40, which is located on the top side of the light-emitting device 20 (located on the upper side of the light-emitting device 20 in the figure) and away from the top of the light-emitting device 20; and the projection of the second light-shielding structure 40 on the surface where the light-emitting device 20 is located is located in the gap between the light-emitting devices 20 (not limited to the situation where the projection of the second light-shielding structure 40 is located in the gap between the light-emitting devices 20, and a part of the projection of the second light-shielding structure 40 may also exceed the gap between the light-emitting devices 20 and overlap with the light-emitting devices 20). Figure 7 It can be seen from the figure that the second light shielding structure 40 is not located in the target light emitting direction of the light emitting device 20. If the target light emitting direction of the light emitting device 20 is taken as the top, the second light shielding structure 40 is located obliquely above the light emitting device 20. When the light emitting device 20 emits light, the second light shielding structure 40 is not located on the light emitting path of the light emitted upward in the target light emitting direction, and no shielding occurs; however, a portion of the light emitted obliquely upward will be irradiated on the second light shielding structure 40. For this portion of light, the second light shielding structure 40 can block the propagation of this portion of light, and the shielding of this portion of light emitted obliquely relative to the target light emitting direction plays a collimating role and effect, which can improve light crosstalk.

[0093] exist Figure 7 In the structure shown, the first light shielding structure 30 is flush with the top of the light emitting device 20. However, it should be noted that in this embodiment, the first light shielding structure 30 may also be higher than the top of the light emitting device 20, that is, Figure 1 and Figure 6 When the first shading structure 30 is higher than the top of the light emitting device 20, the portion of the first light emitting device 30 that is higher than the top of the light emitting device 20 and the second shading structure 40 can collimate the light emitted by the light emitting device 20 toward the target light emitting direction. The two work together to achieve a better collimation effect, thereby better improving light crosstalk.

[0094] In a further embodiment of the light-emitting substrate, the light-emitting substrate has a multi-layer second light-shielding structure 40, and the multi-layer second light-shielding structure 40 is sequentially spaced apart in the target light-emitting direction of the light-emitting device 20 (not shown in the figure). In the case where the second light-shielding structure 40 is multi-layered, among the light rays emitted obliquely relative to the target light-emitting direction of the light-emitting device 20, more light rays will be irradiated on the second light-shielding structure 40 and blocked by the second light-shielding structure 40, so that the multiple second light-shielding structures 40 can achieve a better collimation effect, and can also better improve the crosstalk of light.

[0095] Specifically, similar to the first shading structure 30, the material of the second shading structure 40 can also be a black matrix or a metal. When the material of the second shading structure 40 is a metal, molybdenum, copper, aluminum or other metal materials can be selected. However, unlike the first shading structure 30, for the second shading structure 40, the second shading structure 40 is preferably a metal or other material with a low reflectivity, or a material with a good light absorption effect. The second shading structure 40 made of these preferred materials can better reflect the light irradiated thereon, preventing the reflected light from entering the corresponding area of ​​other light-emitting devices 20 and generating light crosstalk.

[0096] In one embodiment of the light emitting substrate, Figure 8 As shown, the light-emitting substrate includes a light-guiding column 50 , the refractive index of the material of the light-guiding column 50 is higher than the first set value; the light-guiding column 50 corresponds to the light-emitting device 20 in the target light-emitting direction of the light-emitting device 20 .

[0097] In the target light-emitting direction of the light-emitting device 20, the light guide column 50 corresponds to the light-emitting device 20, which means that the light guide column 50 is located on the propagation path of the light emitted by the light-emitting device 20 toward the target light-emitting direction. The light emitted from the side of the light-emitting device 20 toward the target light-emitting direction, including the light whose emission direction is strictly consistent with the target light-emitting direction and the light whose emission direction is inclined relative to the target light-emitting direction, will be incident from the end of the light guide column 50 facing the light-emitting device 20 and enter the light guide column 50.

[0098] For the light whose emission direction is strictly consistent with the target light emission direction, it will be directly emitted from the end of the light guide column 50 facing the light emission surface of the light emitting substrate in the light guide column 50 according to its emission direction that is strictly consistent with the target light emission direction, and finally emitted to the outside from the light emission surface of the light emitting substrate. In this process, this part of the light will not come into contact with the side wall of the light guide column 50.

[0099] For the light emitted in an inclined direction relative to the target light emitting direction, the part with a smaller inclination angle will also illuminate the end of the light emitting surface of the light guide column 50 facing the light emitting substrate and emit when propagating in the light guide column 50, instead of irradiating the side wall of the light guide column 50. This part of the light can be regarded as equivalent to the light whose emission direction is strictly consistent with the target light emitting direction, and will also directly reach the end of the light emitting surface of the light guide column 50 facing the light emitting substrate from the end of the light guide column 50 facing the light emitting device 20, and be emitted to the outside from the light emitting surface of the light guide substrate.

[0100] As for the light whose exit direction is inclined at a large angle relative to the target light exit direction, it will irradiate the side wall of the light guide column 50 when propagating in the light guide column 50. For this part of the light, by setting the first setting value to a suitable value, the refractive index of the light guide column 50 can be made higher, higher than the refractive index of the area between the light guide columns 50; in this case, the light in this part of the light that irradiates the side wall of the light guide column 50 at a required angle will be totally reflected, and will not be refracted and emitted from the light guide column 50 from the side wall direction, so that the light emitted from the side to other light-emitting device 20 areas can be reduced, thereby improving the crosstalk of light. At the same time, this part of the light is totally reflected, confined to the light guide column 50 and propagated to one end of the light guide column 50 facing the light exit surface of the light-emitting substrate, so that the amount of light emitted from the target light exit direction can be increased, the brightness of the light can be improved, and a better light exit effect can be provided. Specifically, the refractive index of the light guide column can be set at 1.8 to 2.5.

[0101] In one embodiment of the light emitting substrate, Figure 8 As shown, there is an inter-column structure 51 between adjacent light guide columns 50, and the refractive index of the inter-column structure 51 is lower than the second set value, and the second set value is smaller than the first set value. By setting the second set value to a suitable value, the condition for the light in the light guide column 50 to be totally reflected at the side wall of the light guide column 50 can be lowered, so that more light can be totally reflected more easily, and the effect of improving the crosstalk and collimation of light can be achieved better. Specifically, the refractive index of the inter-column structure 51 can be set to 1 to 1.5.

[0102] In this embodiment, if Figure 8 As shown, the inter-column structure 51 may only be located at the positions corresponding to the gaps between the light emitting devices 20 and the gaps between the light guide pillars 50, but not cover the light guide pillars 50, which affects the light transmittance in the target light emitting direction. In addition, if during the preparation of the inter-column structure 51, a part of the inter-column structure 51 formed will cover the light guide pillar 50, and if the material of the inter-column structure 51 does not significantly affect the light transmittance, the part of the inter-column structure 51 may be retained, such as Fig. 9 As shown, the process and time for removing the part can be reduced.

[0103] In other embodiments of the light-emitting substrate, a dedicated inter-column structure 51 may not be formed between adjacent light-guiding columns 50, and the area between adjacent light-guiding columns 50 may be left empty, such as Fig.10 The refractive index of air is slightly greater than 1. In this case, a suitable first setting value can be set, such as the above-mentioned refractive index range of 1.8 to 2.5, so that the refractive index of the light guide column 50 can meet the requirement that the light in the light guide column 50 is totally reflected at the side wall of the light guide column 50 .

[0104] In one embodiment of the present invention, the light emitting substrate may include one or more planarization layers 60 covering the light emitting device 20, for example, Figure 7 In the embodiment shown, the light-emitting substrate has three planarization layers 60, and the three planarization layers 60 are all located above the light-emitting device 20; wherein the first planarization layer 60a is formed above the first light-shielding structure 20 (the formed part is thinned and removed in the subsequent process, and the remaining part is connected to the second planarization layer 60b), the second planarization layer 60b is below the second light-shielding structure 30, and the third planarization layer 60c is above the second light-shielding structure. In this embodiment, for each planarization layer 60, the transmittance of each planarization layer 60 covering the light-emitting device 20 is greater than 90%. The greater the transmittance of the planarization layer 60, the more light can be emitted from the light-emitting surface of the light-emitting substrate, and the higher the upper limit of the brightness of the light-emitting surface of the light-emitting substrate.

[0105] The method for preparing a light-emitting substrate provided by the present invention can prepare the light-emitting substrate described in the above light-emitting substrate embodiment.

[0106] In one embodiment of the present invention, the method for preparing the light-emitting substrate includes the following steps S1 to S3: Fig.11 shown.

[0107] Step S1, providing a substrate 10 having a light emitting device 20, such as Fig.12 shown.

[0108] In step S1 , the substrate 10 may be a hard substrate such as a conventional glass substrate, or a flexible substrate such as an ultra-thin glass substrate or polyimide substrate.

[0109] There are usually multiple light-emitting devices 20 on the substrate 10. Each light-emitting device 20 can be an LED, or can be a light-emitting device of other types other than LED. When selecting LED as the light-emitting device 20, a miniaturized LED device can be selected, such as Mini LED (LED chip size is 100 to 300 microns) or Micro LED (LED chip size is less than 100 microns). Of course, ordinary-sized LEDs (LED chip size is greater than 300 microns) can also be used.

[0110] Step S2, forming a first light shielding material layer: forming a first light shielding material layer 301 on the substrate 10 having the light emitting device 20, covering the light emitting device 20 and the gap between the adjacent light emitting devices 20, such as Fig.13 and Fig.14 shown.

[0111] In step S2 , the material of the first light shielding material layer 301 may be a black matrix or a metal, and the metal that can be selected is, for example, molybdenum, copper, aluminum or other metals.

[0112] like Fig.13 and Fig.14 As shown, when the first light-shielding material layer 301 is formed on the substrate 10 , the first light-shielding material layer 301 not only covers the gaps between adjacent light-emitting devices 20 , but also covers the light-emitting devices 20 .

[0113] Step S3 , forming a first light shielding structure 30 : removing the pattern of the first light shielding material layer 301 covering the light emitting device 20 in at least a portion of the area corresponding to the light emitting device 20 , so as to expose at least a portion of the light emitting device 20 .

[0114] In the structure after completing step S3, the exposed area of ​​the light emitting device 20 should be above a set lower limit value, that is, the area where the light emitting device 20 is covered by the retained first light shielding material layer 301 and the two overlap should be smaller than the set value. The type of the set value can be the absolute value of the area of ​​the overlapping area of ​​the two, or the proportion of the overlapping area of ​​the two in the entire light emitting device 20.

[0115] In one embodiment of the present invention, the material of the first light shielding material layer 301 is a black matrix. In step S3, based on, for example Fig.13 When removing the pattern of the first light shielding material layer 301 covering the light emitting device 20, the first light shielding material layer 301 is etched in its entirety, so that the first light shielding material layer 301 is thinned to a height corresponding to the top of the light emitting device 20, so that at least a portion of the light emitting device 20 is exposed. In the above process, there is no need to use a mask for selective etching. The structure formed is as shown in FIG. Fig.15 As shown, Fig.15 The figure shows a situation where the retained first light shielding material layer 301 does not overlap with the light emitting device 20 and the light emitting device 20 is completely exposed.

[0116] have Fig.15 The light-emitting substrate of the structure shown has a retained portion of the first light-shielding material layer 301 located between adjacent light-emitting devices 20, which can block light emitted laterally from the side of the light-emitting device 20. This portion of light will not enter the area of ​​other light-emitting devices 20, so that for the light-emitting substrate, it can improve light crosstalk and enhance the light-emitting effect of the light-emitting substrate.

[0117] In another embodiment of the present invention, the material of the first light shielding material layer 301 is also a black matrix. In step S3, based on, for example, Fig.13 When removing the pattern of the first light shielding material layer 301 covering the light emitting device 20, the pattern of the first light shielding material layer 301 covering the light emitting device 20 is removed by etching through a mask exposure etching process, such as Fig.16 As shown above. Fig.15 Compared with the embodiment of the present invention, in the present embodiment, a mask is used to selectively etch the pattern of the first light-shielding material layer 301 to expose at least a portion of the light-emitting device 20; and after etching, the retained first light-shielding material layer 301 is higher than the top of the light-emitting device 20. Fig.16 The figure shows a situation where the retained first light shielding material layer 301 does not overlap with the light emitting device 20 and the light emitting device 20 is completely exposed.

[0118] have Fig.16 The light-emitting substrate of the structure shown in FIG. 1 has a first light-shielding material layer 301, the remaining portion of which is located between adjacent light-emitting devices 20 and is higher than the light-emitting devices 20. Fig.15 Compared with the light-emitting substrate of the structure shown in the figure, it can block the light emitted from the light-emitting device 20 to the side, and this part of the light source emits more light than the side of the light-emitting device 20, so that for the light-emitting substrate, it can better improve the crosstalk of light and improve the light-emitting effect of the light-emitting substrate. In essence, the part of the first light-shielding material layer 301 that is higher than the light-emitting device 20 also plays a role in collimating the light emitted by the light-emitting device 20 in the target light-emitting direction.

[0119] In another embodiment of the present invention, the first light shielding material layer 301 may be a metal layer, specifically molybdenum, copper, aluminum or other metal materials, and preferably a material with high reflectivity. In this embodiment, the step of forming the first light shielding structure 30 in step S3 includes the following steps S31 to S33: Fig.17 shown.

[0120] Step S31, forming a planarization layer 60 (first planarization layer 60a), such as Fig.18 shown.

[0121] Before step S31, since the light emitting device 20 is relatively protruding on the substrate 10, the surface of the substrate 10 is not flat; the surface of the first light shielding material layer 301 formed in step S2 is also not flat. Through step S31, a flat surface can be formed to facilitate subsequent processes.

[0122] Step S32, thinning the planarization layer 60 (first planarization layer 60a) to expose the pattern of the first light shielding material layer 301 covering the light emitting device 20, such as Fig.19 shown.

[0123] In step S32, a maskless process is used to non-selectively etch the planarization layer 60 (first planarization layer 60a) as a whole, and the planarization layer 60 (first planarization layer 60a) is thinned to expose the pattern of the area of ​​the first light-shielding material layer 301 corresponding to the light-emitting device 20, so as to facilitate the subsequent etching of the pattern of the first light-shielding material layer 301 in the exposed area.

[0124] Step S33, in at least a portion of the area corresponding to the light emitting device 20, the pattern of the first light shielding material layer 301 covering the light emitting device 20 is removed to expose at least a portion of the area of ​​the light emitting device 20, such as Fig. 20 shown.

[0125] In step S33, the pattern of the exposed first light-shielding material layer 301, that is, the area of ​​the first light-shielding material layer 301 corresponding to the light-emitting device 20, is removed through a patterning process of mask exposure and etching, while the first light-shielding material layer 301 and the planarization layer 60 (first planarization layer 60a) in other areas are retained, ultimately exposing at least a portion of the light-emitting device 20. Fig. 20 The figure shows a situation where the retained first light shielding material layer 301 does not overlap with the light emitting device 20 and the light emitting device 20 is completely exposed.

[0126] In one embodiment of the present invention, it is also possible to Fig.15 , Fig.16 and Fig. 20 On the basis of the structure shown, the process steps of sequence a are continued to be executed, and the process steps of sequence a include step S4a.

[0127] Step S4a, performing a patterning process to form a second light shielding material layer 302, the second light shielding material layer 302 is formed and superimposed on the retained first light shielding material layer 301. Fig.15 Based on the structure shown in FIG. 1 , performing step S4a will result in Fig.21 The structure shown.

[0128] In step S4a, the material of the second light-shielding material layer 302 may be the same as or different from the material of the first light-shielding material layer 301. For example, when the material of the first light-shielding material layer 301 is a black matrix, the material of the second light-shielding material layer 302 may be a black matrix or a metal; when the material of the first light-shielding material layer 301 is a metal, the second light-shielding material layer 302 may be a black matrix or the same metal material or a different metal material.

[0129] In the embodiment based on step S4a, the first light shielding material layer 301 and the second light shielding material layer 302 together form the first light shielding structure 30. Different from the above embodiment based on step S3 (see Fig.15 , Fig.16 and Fig. 20 ), in the above embodiment, the first light-shielding structure 30 only includes the first light-shielding material layer 301.

[0130] In the case where the height of the first shading material layer 301 retained in step S3 is flush with the top of the light-emitting device 20, the second shading material layer 302 formed on the first shading material layer 301 in step S4 can make the first shading structure 30 higher than the top of the light-emitting device 20, thereby producing a collimating effect. In the case where the first shading material layer 301 retained in step S3 is higher than the top of the light-emitting device 20, the second shading material layer 302 formed on the first shading material layer 301 in step S4 can further increase the height of the first shading structure 30, further higher than the top of the light-emitting device 20, thereby producing a better collimating effect. In short, the formation of the second shading material layer 302 in step S4 can further improve the crosstalk of light.

[0131] In another embodiment of the present invention, Fig.15 , Fig.16 and Fig. 20 On the basis of the structure shown, the process steps of sequence b are continued to be executed, and the process steps of sequence b include the following step S4b.

[0132] Step S4b, forming a second light shielding structure 40: forming a planarization layer 60 (second planarization layer 60b), and forming a layer of light shielding pattern on the planarization layer 60 (second planarization layer 60b) in the area corresponding to the gap between the light emitting devices 20, the light shielding pattern is the second light shielding structure 40. Fig. 20 Based on the structure shown in FIG. 1 , performing step S4b will result in Fig. 22 The structure shown.

[0133] In step S4b, a shading pattern can be formed by a patterning process of exposure and selective etching using a mask. Specifically, when forming a shading pattern, opaque materials such as a black matrix and a metal material can be used. When the material of the second shading structure 40 is a metal, molybdenum, copper, aluminum or other metal materials can be selected. However, unlike the first shading structure 30, for the second shading structure 40, the second shading structure 40 is preferably a metal or other material with a low reflectivity, or a material with a good light absorption effect. The second shading structure 40 made of these preferred materials can better reflect the light irradiated thereon, preventing the reflected light from entering the corresponding area of ​​other light-emitting devices 20 and generating light crosstalk.

[0134] After step S4b, in order to make the surface flat and facilitate the subsequent other processes, a planarization layer 60 (third planarization layer 60c) may be formed on the second light shielding structure 40. Fig.23 shown.

[0135] In a further preferred embodiment of the present invention, the process steps of sequence b may further include the following step S5b.

[0136] Step S5b, repeating the step of forming the second light shielding structure 40 in step S4b, to form multiple layers of the second light shielding structure 40 on the light emitting substrate.

[0137] When the second shading structure 40 is multi-layered, among the light emitted by the light-emitting device 20 at an angle relative to the target light emitting direction, more light will be irradiated on the second shading structure 40 and blocked by the second shading structure 40, so that the multiple second shading structures 40 can achieve a better collimation effect and can also better improve light crosstalk.

[0138] In another embodiment of the present invention, Fig.15 , Fig.16 and Fig. 20 Based on the structure shown, the process steps of the c sequence are continued to be executed, and the process steps of the c sequence include the following step S4c.

[0139] Step S4c, forming a light guide column 50 in the target light emitting direction of the light emitting device 20, wherein the refractive index of the material forming the light guide column 50 is greater than the first set value. Fig. 20 Based on the structure shown in FIG. 1 , performing step S4c will result in Fig.24 The structure shown.

[0140] In the target light-emitting direction of the light-emitting device 20, the formed light guide column 50 corresponds to the light-emitting device 20, which means that the light guide column 50 is located on the propagation path of the light emitted by the light-emitting device 20 toward the target light-emitting direction. The light emitted from the side of the light-emitting device 20 toward the target light-emitting direction, including the light whose emission direction is strictly consistent with the target light-emitting direction and the light whose emission direction is inclined relative to the target light-emitting direction, will be incident from the end of the light guide column 50 facing the light-emitting device 20 and enter the light guide column 50.

[0141] For the light whose emission direction is strictly consistent with the target light emission direction, it will be directly emitted from the end of the light guide column 50 facing the light emission surface of the light emitting substrate in the light guide column 50 according to its emission direction that is strictly consistent with the target light emission direction, and finally emitted to the outside from the light emission surface of the light emitting substrate. In this process, this part of the light will not come into contact with the side wall of the light guide column 50.

[0142] For the light emitted in an inclined direction relative to the target light emitting direction, the part with a smaller inclination angle will also illuminate the end of the light emitting surface of the light guide column 50 facing the light emitting substrate and emit when propagating in the light guide column 50, instead of irradiating the side wall of the light guide column 50. This part of the light can be regarded as equivalent to the light whose emission direction is strictly consistent with the target light emitting direction, and will also directly reach the end of the light emitting surface of the light guide column 50 facing the light emitting substrate from the end of the light guide column 50 facing the light emitting device 20, and be emitted to the outside from the light emitting surface of the light guide substrate.

[0143] As for the light whose exit direction is inclined at a large angle relative to the target light exit direction, it will irradiate the side wall of the light guide column 50 when propagating in the light guide column 50. For this part of the light, by setting the first setting value to a suitable value, the refractive index of the light guide column 50 can be made higher, higher than the refractive index of the area between the light guide columns 50; in this case, the light in this part of the light that irradiates the side wall of the light guide column 50 at a required angle will be totally reflected, and will not be refracted and emitted from the light guide column 50 from the side wall direction, so that the light emitted from the side to other light-emitting device 20 areas can be reduced, thereby improving the crosstalk of light. At the same time, this part of the light is totally reflected, confined to the light guide column 50 and propagated to one end of the light guide column 50 facing the light exit surface of the light-emitting substrate, so that the amount of light emitted from the target light exit direction can be increased, the brightness of the light can be improved, and a better light exit effect can be provided. Specifically, the refractive index of the light guide column 50 can be set at 1.8 to 2.5.

[0144] In step S4c, the light guide pillar 50 may be formed by transfer printing, nano-imprinting, or selective etching after exposure of a hard mask.

[0145] In a further preferred embodiment of the present invention, the process steps of the c sequence may further include the following step S5c.

[0146] Step S5c, after forming the light guide pillars 50, a layer of filling material is deposited, and the deposited filling material fills the gaps between adjacent light guide pillars 50, such as Fig.25 The refractive index of the material filled in this step is less than the second set value, and the second set value is less than the first set value.

[0147] The material filled in step S5 c forms inter-pillar structures 51 between the light guiding pillars 50 .

[0148] In step S5c, the second setting value is set to a suitable value, which can make the condition for the light in the light guide column 50 to be totally reflected at the side wall of the light guide column 50 lower, so that more light can be totally reflected more easily, and the effect of improving the crosstalk and collimation of light can be achieved. Specifically, the refractive index of the inter-column structure 51 can be set to 1 to 1.5.

[0149] In a further preferred embodiment of the present invention, the process steps of the c sequence may further include the following step S6c.

[0150] Step S6c, removing the filling material covering the light guide column 50, such as Fig.26 shown.

[0151] In the process of forming the inter-column structure 51 in step S5c, the inter-column structure 51 may be located only at positions corresponding to the gaps between the light-emitting devices 20 and the gaps between the light-guiding columns 50, and may also cover the light-guiding columns 50. The inter-column structure 51 partially covered on the light-guiding columns 50 may absorb light emitted from the side of the light-guiding columns 50 facing the light-emitting substrate, which may affect the light efficiency of the light emitted by the light-emitting device 20 to a certain extent, and affect the upper limit of the brightness of the light-emitting surface of the light-emitting substrate.

[0152] In step S6c, the portion of the inter-column structure 51 covering the light-guiding column 50 is removed, thereby eliminating the adverse effect of the inter-column structure 51 on the transmission of light emitted by the light-emitting device 20, improving the transmittance of light in the target light-emitting direction, and increasing the upper limit of the brightness of the light-emitting surface of the light-emitting substrate.

[0153] The present invention further provides a light-using device, in an embodiment of which the light-using device comprises the light-emitting substrate described in the embodiment of the light-emitting substrate.

[0154] In one embodiment, the light-using device may be a backlight source, which may be used in, for example, a liquid crystal display panel to provide backlight. When the light-using device is a backlight source, the backlight source using the above-mentioned light-emitting substrate may achieve more accurate local dimming due to improved light crosstalk.

[0155] In another embodiment, the light-using device may be a display device. For example, when the light-emitting device is a Mini LED or a Micro LED, each Mini LED or Micro LED can be used as a separate pixel or sub-pixel, and thus can be directly used for display.

[0156] In another embodiment, the light-using device may also be a 3D printing device. In the 3D printing device using the above-mentioned light-emitting substrate, since the crosstalk of light is improved, the graphics can be printed more accurately and the printing precision can be improved.

[0157] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0158] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. 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 invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A light-emitting substrate, characterized in that: The light-emitting substrate comprises a substrate, on which a plurality of light-emitting devices are arranged at intervals; A first light shielding structure is provided at the gap between the light emitting devices, and the first light shielding structure is used to shield the light emitted laterally by the light emitting devices; The first light-shielding structure and the light-emitting device do not overlap in the target light-emitting direction of the light-emitting device, or the overlapping area between the first light-shielding structure and the light-emitting device in the target light-emitting direction of the light-emitting device is smaller than a set value; The light-emitting substrate further comprises a second shading structure, which is located at the top end side of the light-emitting device and away from the top end of the light-emitting device; the projection of the second shading structure on the surface where the light-emitting device is located is located at the gap between the light-emitting devices.

2. The light-emitting substrate according to claim 1, characterized in that: The first light shielding structure is made of black matrix or metal.

3. The light-emitting substrate according to claim 1, characterized in that: The first light shading structure includes a bottom, a side and a top; the bottom of the first light shading structure faces the substrate; the side of the first light shading structure faces the light emitting device and surrounds the light emitting device; the top of the first light shading structure is flush with or higher than the top of the light emitting device.

4. The light-emitting substrate according to any one of claims 1 to 3, characterized in that: The first light shielding structure is a single-layer or multi-layer structure.

5. The light-emitting substrate according to claim 1, characterized in that: The light-emitting substrate has a multi-layer second light-shielding structure, and the multi-layer second light-shielding structure is sequentially arranged at intervals in the target light-emitting direction of the light-emitting device.

6. The light-emitting substrate according to claim 1 or 5, characterized in that: The second light shielding structure is made of black matrix or metal.

7. The light-emitting substrate according to claim 1, characterized in that: The light-emitting substrate includes a light-guiding column, the refractive index of the material of the light-guiding column is higher than a first set value; the light-guiding column corresponds to the light-emitting device in the target light-emitting direction of the light-emitting device.

8. The light-emitting substrate according to claim 7, characterized in that: An inter-column structure is provided between adjacent light-guiding columns, and a refractive index of the inter-column structure is lower than a second set value, and the second set value is smaller than the first set value.

9. The light-emitting substrate according to claim 7, characterized in that: The refractive index of the light guide column is between 1.8 and 2.

5.

10. The light emitting substrate according to claim 8, characterized in that: The refractive index of the inter-column structure is between 1 and 1.

5.

11. The light emitting substrate according to claim 1, characterized in that: The light-emitting substrate includes one or more planarization layers covering the light-emitting device, and the light transmittance of each planarization layer covering the light-emitting device is greater than 90%.

12. A method for preparing a light-emitting substrate, characterized in that: include: Forming a first light-shielding material layer: forming a first light-shielding material layer covering the light-emitting devices and gaps between the light-emitting devices on the substrate having the light-emitting devices; Forming a first light shielding structure: removing the first light shielding material layer pattern covering the light emitting device in at least a portion of the region corresponding to the light emitting device, so as to expose at least a portion of the region of the light emitting device; The method for preparing the light-emitting substrate further includes: Forming a second light-shielding structure: forming a planarization layer, and forming a light-shielding pattern on the planarization layer in an area corresponding to the gap between the light-emitting devices, wherein the light-shielding pattern is a second light-shielding structure.

13. The method for preparing a light-emitting substrate according to claim 12, characterized in that: The method for preparing the light-emitting substrate further includes: A patterning process is performed to form a second light-shielding material layer, wherein the second light-shielding material layer is formed and overlapped on the retained first light-shielding material layer.

14. The method for preparing a light-emitting substrate according to claim 12, characterized in that: The method for preparing the light-emitting substrate further includes: A light guide column is formed in a target light emitting direction of the light emitting device, and the refractive index of the material forming the light guide column is greater than a first set value.

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