Packaging film material, display substrate and display module

Abstract

The invention discloses a packaging film material, a display substrate and a display module, the packaging film material is used for packaging an LED display substrate, and the packaging film material comprises a plastic film and an adhesive layer located on one side of the plastic film; wherein the plastic film comprises a deep-color film, and the transmittance of the deep-color film to visible light ranges from 30% to 60%.

Description

Packaging film materials, display substrates and display modules Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a packaging film material, a display substrate, and a display module. Background Art

[0002] Current surface packaging methods for LED (Light-Emitting Diode) direct display products include film packaging. In this film packaging method, the packaging film used for packaging contains a dark film layer, so that the surface of the display product appears dark when the display is not on.

[0003] Summary of the Invention

[0004] The present disclosure provides a packaging film material, a display substrate and a display module.

[0005] In a first aspect, the present disclosure provides a packaging film material for packaging an LED display substrate, wherein the packaging film material comprises a plastic film and an adhesive layer located on one side of the plastic film;

[0006] Wherein, the plastic film comprises a dark film, and the transmittance of the dark film to visible light is in the range of 30% to 60%.

[0007] In some embodiments, the plastic film only includes the dark film; the material of the dark film is a substrate doped with black dye, and the material of the substrate is any one of PET, PC, PI, and TAC.

[0008] In some embodiments, the plastic film has a thickness greater than or equal to 50 microns.

[0009] In some embodiments, the plastic film comprises a dark thin layer and a transparent plastic layer, wherein the dark thin layer is attached to the transparent plastic layer;

[0010] The material of the dark thin layer is black dye.

[0011] In some embodiments, the transparent plastic layer has a thickness greater than or equal to 50 micrometers.

[0012] In some embodiments, the adhesive layer includes diffusion particles, and the diffusion particles are used to scatter light.

[0013] In some embodiments, the material of the diffusion particles is at least one of silicon dioxide and titanium dioxide.

[0014] In some embodiments, the diffusion particles are evenly distributed in the adhesive layer.

[0015] In some embodiments, the packaging film material includes a diffusion particle layer located between the glue layer and the plastic film, and the diffusion particle layer is used to scatter light.

[0016] In some embodiments, the surface of the plastic film away from the adhesive layer is provided with at least one of an anti-glare layer, an anti-reflection layer, and an anti-fouling layer;

[0017] Wherein, the anti-glare layer is a coating layer attached to the surface of the plastic film, or the anti-glare layer is obtained by treating the surface of the plastic film.

[0018] In some embodiments, the plastic film includes a first plastic layer and a second plastic layer that are stacked;

[0019] Wherein, one of the first plastic layer and the second plastic layer is a transparent film, and the other is the dark film; or,

[0020] The first plastic layer and the second plastic layer are both transparent films. A first adhesive layer is provided between the first plastic layer and the second plastic layer. The first adhesive layer is the dark film.

[0021] In some embodiments, the first plastic layer is a transparent film, and the second plastic layer is the dark film, or the first plastic layer is the dark film, and the second plastic layer is a transparent film;

[0022] A second adhesive layer is further included between the first plastic layer and the second plastic layer. The transmittance of the second adhesive layer to visible light is greater than the transmittance of the dark film to visible light.

[0023] In some embodiments, the transparent film has a visible light transmittance greater than 90%.

[0024] In some embodiments, the visible light transmittance of the second adhesive layer is greater than or equal to 95%.

[0025] In some embodiments, the material of the transparent film is any one of PET, PC, PI, and TAC; the dark film includes a substrate and carbon black particles dispersed in the substrate, and the material of the substrate is any one of PET, PC, PI, and TAC.

[0026] In some embodiments, the total thickness of the first plastic layer, the second plastic layer, and the second adhesive layer is between 100 μm and 300 μm.

[0027] In some embodiments, the second adhesive layer is configured to scatter visible light.

[0028] In some embodiments, the first plastic layer and the second plastic layer are both transparent films, and the material of the transparent films is any one of PET, PC, PI, and TAC;

[0029] The first adhesive layer includes an adhesive layer matrix and a black pigment located in the matrix. The material of the adhesive layer matrix includes silicon-based optical adhesive or epoxy resin.

[0030] In some embodiments, the transmittance of the first plastic layer, the second plastic layer, and the first adhesive layer as a whole to visible light is in the range of 30% to 60%.

[0031] In some embodiments, the total thickness of the first plastic layer, the second plastic layer, and the first adhesive layer is between 100 μm and 300 μm.

[0032] In some embodiments, the total thickness of the first plastic layer and the second plastic layer is between 50 μm and 150 μm.

[0033] In some embodiments, the first adhesive layer is configured to scatter visible light.

[0034] In some embodiments, a surface of the second plastic layer away from the first plastic layer is provided with at least one of an anti-glare layer, an anti-reflection layer, and an anti-fouling layer;

[0035] Wherein, the anti-glare layer is a coating layer attached to the surface of the plastic film, or the anti-glare layer is obtained by treating the surface of the plastic film.

[0036] In some embodiments, the adhesive layer includes a matrix and scattering particles distributed in the matrix, and the scattering particles are used to scatter visible light.

[0037] In some embodiments, the adhesive layer further comprises a black pigment within the matrix.

[0038] In some embodiments, a first adhesive layer is further included between the first plastic layer and the second plastic layer, and the hardness of the first plastic layer, the second plastic layer and the first adhesive layer as a whole is within the range of 2H to 4H; or

[0039] A second adhesive layer is further included between the first plastic layer and the second plastic layer. The hardness of the first plastic layer, the second plastic layer and the second adhesive layer as a whole is within a range of 2H to 4H.

[0040] The present disclosure further provides a display substrate, which includes a base, an LED light-emitting chip located on the base, and the above-mentioned packaging film material;

[0041] Wherein, the LED light-emitting chip is located between the substrate and the packaging film material.

[0042] In some embodiments, the adhesive layer includes a first portion and a second portion, wherein the first portion is located between the LED light-emitting chip and the first plastic layer, and the second portion is located between adjacent LED light-emitting chips.

[0043] The first portion and the second portion are in contact with each other.

[0044] In some embodiments, the adhesive layer is conformal to the surface of the substrate facing the packaging film material and the LED light-emitting chip assembly.

[0045] In some embodiments, a surface of the plastic film facing the substrate is parallel to the substrate.

[0046] In some embodiments, when the packaging film material includes a diffusion particle layer located between the glue layer and the plastic film, a surface of the diffusion particle layer facing the substrate is parallel to the substrate.

[0047] In some embodiments, the thickness of the diffusion particle layer is greater than or equal to 26 micrometers.

[0048] In some embodiments, the thickness of the plastic film is greater than or equal to 50 microns;

[0049] The thickness of the adhesive layer is greater than or equal to 96 microns.

[0050] In some embodiments, when the diffusion particles are uniformly distributed in the adhesive layer, the thickness of the plastic film is greater than or equal to 50 microns;

[0051] The thickness of the adhesive layer is greater than or equal to 96 microns.

[0052] In some embodiments, the maximum distance H1 between the surface of the packaging film away from the substrate and the substrate and the minimum horizontal distance D between the LED chip and the edge of the packaging film satisfy the following conditions: H1≤A*D, where A is between 1.12 and 1.31.

[0053] The minimum horizontal distance is the minimum distance parallel to the substrate direction.

[0054] In some embodiments, H1 is less than or equal to 230 microns.

[0055] The present disclosure further provides a display substrate, comprising a base, an LED light-emitting chip located on the base, and a packaging film material, wherein the LED light-emitting chip is located between the base and the packaging film material;

[0056] The packaging film material comprises a laminated adhesive layer and a plastic film, wherein the adhesive layer is located on a side of the plastic film facing the substrate, and the plastic film comprises a transparent film; a dark coating is attached to the surface of the substrate facing the packaging film material.

[0057] In some embodiments, the maximum distance H1 between the surface of the packaging film away from the substrate and the substrate and the minimum horizontal distance D between the LED chip and the edge of the packaging film satisfy the following conditions: H1≤A*D, where A is between 1.12 and 1.31.

[0058] The minimum horizontal distance is the minimum distance parallel to the substrate direction.

[0059] In some embodiments, the adhesive layer includes diffusion particles, and the diffusion particles are used to scatter light.

[0060] In some embodiments, the present disclosure further provides a display module comprising a plurality of display substrates as described above arranged in an array. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0062] FIG1 is a schematic diagram of a packaging film material provided in some embodiments.

[0063] FIG. 2 is a schematic diagram of packaging film materials provided in other embodiments.

[0064] 3 to 10B are schematic diagrams of various structures of packaging film materials provided in embodiments of the present disclosure.

[0065] 11A to 11D are various schematic diagrams of display substrates provided in some embodiments of the present disclosure.

[0066] FIG. 11E is a schematic diagram of a display substrate provided in some other embodiments of the present disclosure.

[0067] FIG12 is a schematic diagram of the vacuum pressing process provided by the apparatus according to an embodiment of the present disclosure.

[0068] FIG. 13 is a schematic diagram of a display substrate in a normal display state.

[0069] 14 and 15 are schematic diagrams of the optical path where color slits appear. DETAILED DESCRIPTION

[0070] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0071] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0072] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0073] As used herein, "parallel" and "perpendicular" include the conditions described and conditions similar to the conditions described, and the range of the similar conditions is within an acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range for approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°.

[0074] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0075] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0076] FIG1 is a schematic diagram of a packaging film material provided in some embodiments, and FIG2 is a schematic diagram of a packaging film material provided in other embodiments, which is used for packaging LED display substrates. As shown in FIG1 , the packaging film material includes: a transparent substrate 1 and a dark adhesive layer 2 arranged on one side of the transparent substrate 1. As shown in FIG2 , in other embodiments, the packaging film material includes: a glue layer 3, a dark adhesive layer 2, and a transparent substrate 1 stacked in sequence. When the packaging film material of FIG1 and FIG2 is used to package the LED display substrate, the packaging film material is pressed onto the LED display substrate to package the LED display substrate. After the packaging is completed, the dark adhesive layer 2 is located on the side of the transparent substrate 1 facing the display substrate. However, the dark adhesive layer 2 is usually formed by coating dark glue on the transparent substrate 1 and curing it. Due to the limitations of the coating process, the thickness accuracy of the dark adhesive layer 2 is low, resulting in a certain fluctuation in the ink color of the packaging film layer (that is, the L value of the packaging film layer in the LAB space has a certain deviation from the target value). In addition, the dark adhesive layer 2 formed after the glue cures has a low hardness. After the encapsulation film layer is encapsulated on the LED display substrate, the encapsulated chip can easily squeeze or puncture the dark adhesive layer 2, which also leads to low thickness accuracy of the dark adhesive layer 2. When multiple encapsulated display substrates are spliced ​​into a larger spliced ​​display screen, the ink color will be inconsistent in different locations on the spliced ​​display screen.

[0077] In order to solve the above problems, the present disclosure provides a packaging film material for packaging an LED display substrate, which can be a Mini-LED display substrate or a Micro-LED display substrate. Figures 3 to 10B are schematic diagrams of various structures of the packaging film materials provided in the embodiments of the present disclosure. As shown in Figures 3 to 10B, the packaging film material includes a plastic film 100 and an adhesive layer 30 located on one side of the plastic film 100. Among them, the plastic film 100 includes a dark film DF, wherein the dark film DF in the embodiment of the present disclosure refers to a film with a low transmittance to visible light (for example, not more than 75%) and visually appears in a dark color such as black or dark gray.

[0078] In some embodiments, the transmittance of the dark film DF to visible light is in the range of 30% to 60%. For example, the transmittance of the dark film DF to visible light is between 30% and 40%. For another example, the transmittance of the dark film DF to visible light is between 40% and 60%.

[0079] In the embodiment of the present disclosure, a plastic film 100 is provided to enable the packaging film material to achieve a visual ink color effect, without the need for a coating process. Moreover, compared with the adhesive layer formed after the glue is cured, the plastic film 100 has a higher hardness, and its thickness is not affected by the extrusion of the light-emitting chip, thereby reducing the ink color fluctuation of the packaging film material, and further improving the ink color consistency of the spliced ​​display screen after multiple packaged display devices are spliced.

[0080] The packaging film material in the present disclosure is described in detail below with reference to the accompanying drawings.

[0081] In some embodiments, as shown in FIG3 , the plastic film 100 includes only a dark film, the material of which includes a substrate doped with a black dye, and the material of the substrate is any one of PET (polyethylene terephthalate), PC (polycarbonate), PI (polyimide), and TAC (triacetyl cellulose).

[0082] In some embodiments, the thickness of the plastic film 100 is greater than or equal to 50 micrometers to ensure that the packaging film material can provide sufficient mechanical strength support.

[0083] For example, the thickness of the plastic film 100 is 50 micrometers, or 60 micrometers, or 70 micrometers, or 80 micrometers, or 90 micrometers.

[0084] In some embodiments, the adhesive layer 30 may include diffusion particles, which are used to diffuse light, so that the packaging film material can diffuse the light of the LED display substrate to produce a uniform light output effect.

[0085] For example, the material of the diffusion particles may include at least one of titanium dioxide, silicone, zirconium dioxide, and silicon dioxide. For example, the diffusion particles may include silicon dioxide particles; titanium dioxide particles; or other particles, such as silicone particles or zirconium dioxide particles. Of course, the diffusion particles may include a mixture of at least two of the above-mentioned particles.

[0086] In some embodiments, the diffusion particles are evenly distributed in the adhesive layer 30 to improve the light uniformity of the LED display substrate after the light passes through the packaging film.

[0087] In some embodiments, the matrix of the adhesive layer 30 is a transparent optical adhesive, such as a silicon-based optical adhesive or epoxy resin.

[0088] In some embodiments, the matrix can be a UV-cured product or a thermally cured product. Before curing, the UV (Ultraviolet) particles or thermally cured particles provided in the matrix are cured after the matrix containing these particles undergoes a curing treatment (UV irradiation or thermal treatment), thereby hardening the matrix of the adhesive layer 30 as a whole, eliminating uncured parts, and reducing the creep by approximately 50%, thereby greatly reducing adhesion during assembly and disassembly. The above-mentioned curing treatment is the process of converting a substance (a matrix containing UV particles or thermally cured particles) from a low molecular weight to a high molecular weight (a substance generated after curing). Taking UV curing as an example, the principle can be as follows: UV particles are photosensitivity, and under UV light irradiation, they are photo-initiated to form excited ecological molecules, which decompose into free radicals or ions, causing unsaturated organic matter to undergo chemical reactions such as polymerization, grafting, and cross-linking to achieve the purpose of curing.

[0089] In some embodiments, the thickness of the adhesive layer 30 can be greater than the height of the LED light-emitting chip to ensure that, after the encapsulation film is attached to the display substrate, a portion of the adhesive layer 30 is located on the side of the light-emitting chip away from the substrate, thereby protecting the LED light-emitting chip without damaging the LED light-emitting chip or damaging the plastic film 100. In one example, the difference between the thickness of the adhesive layer 30 and the height of the LED light-emitting chip is between 10 and 100 μm, for example, between 10 and 30 μm, or between 20 and 50 μm, or between 50 and 70 μm.

[0090] For example, the difference between the thickness of the adhesive layer 30 and the height of the LED light emitting chip is at least 16 micrometers. Taking the height of the LED light emitting chip as 80 micrometers as an example, the thickness of the adhesive layer 30 is greater than or equal to 96 micrometers.

[0091] In some embodiments, as shown in FIG4 , the packaging film material includes the above-mentioned plastic film 100 and the adhesive layer 30. The materials and thicknesses of the plastic film 100 and the adhesive layer 30 can be found in the description of FIG3 above. In addition, in FIG4 , the packaging film layer may further include a surface treatment layer 80, and the surface treatment layer 80 is located on the side of the plastic film 100 away from the adhesive layer 30. Among them, the surface treatment layer 80 may include at least one of an anti-glare (AG) layer (not shown), an anti-reflection (AR) layer and an anti-fouling (AF) layer (not shown). By providing the anti-glare layer, the packaging film material has the characteristics of anti-glare. By providing the anti-reflection layer, the packaging film material has the advantages of reducing reflection and improving display contrast; by providing the anti-fouling layer, the packaging film layer has the characteristics of being easy to wipe. Among them, the anti-reflection layer can be formed by coating, and the anti-fouling layer can be formed by coating the plastic film 100.

[0092] The anti-glare layer can be obtained by surface treatment (e.g., embossing) of the plastic film 100. After surface treatment, the plastic film 100 forms a rough surface with an anti-glare effect. In practical applications, the plastic film 100 may only be surface treated to form an anti-glare surface without providing an anti-reflection layer or an anti-fouling layer. Alternatively, while providing an anti-glare surface, at least one of the anti-reflection layer and the anti-fouling layer may be formed on the side of the anti-glare surface away from the adhesive layer 30. Alternatively, only at least one of the anti-reflection layer and the anti-fouling layer may be provided without providing an anti-glare surface.

[0093] It should also be noted that, in the above description, the anti-glare effect of the packaging film layer is achieved by treating the surface of the plastic film 100 away from the adhesive layer 30. In other examples, the anti-glare layer can also be attached to the surface of the plastic film 100. For example, an additional coating particle layer is provided on a layer of the plastic film 100 away from the adhesive layer 30 to form an anti-glare layer, which can also enable the packaging film material to achieve an anti-glare effect.

[0094] In addition, when the anti-glare layer, the anti-reflection layer and the anti-fouling layer are simultaneously provided on the side of the plastic film 100 away from the adhesive layer 30 , the anti-fouling layer is located on the side of the anti-reflection layer away from the plastic film 100 , and the anti-glare layer is located on the side of the anti-reflection layer close to the plastic film 100 .

[0095] It should be noted that when the anti-glare layer is a coating layer attached to the plastic film 100, the thickness of the plastic film 100 refers to the thickness of the plastic film 100 itself, and does not include the thickness of the anti-glare layer. If the anti-glare layer is obtained by surface treatment of the plastic film 100, the thickness of the plastic film 100 refers to the thickness of the plastic film 100 after the surface treatment.

[0096] In some embodiments, as shown in Figures 5 and 6, the packaging film material may include the above-mentioned plastic film 100 and the adhesive layer 30, wherein the plastic film 100 includes a dark film DF, and the material of the dark film DF and the thickness of the plastic film 100 can be referred to the above description in Figure 3.

[0097] In some embodiments, as shown in Figures 5 and 6 , the encapsulation film material may further include a diffusion particle layer 90 positioned between the adhesive layer 30 and the plastic film 100. The diffusion particle layer 90 is configured to scatter light. The diffusion particle layer 90 may comprise cured transparent adhesive and diffusion particles uniformly distributed within the adhesive. The diffusion particles may include silica particles, titanium dioxide particles, or other particles such as organosilicon particles or zirconium dioxide particles. Furthermore, the diffusion particles may comprise a mixture of at least two of the aforementioned particles.

[0098] The provision of the diffusion particle layer 90 allows the packaging film to diffuse the light from the LED display substrate, producing a uniform light output effect. Furthermore, the diffusion particle layer 90 is fully cured before the packaging film is attached to the display substrate, thereby improving the display product's anti-collision properties and preventing the diffusion particle layer 90 from being squeezed during the packaging film attachment process, which could lead to uneven distribution of the diffusion particles.

[0099] In some embodiments, as shown in Figures 5 and 6, the thickness of the adhesive layer 30 can be greater than the height of the LED light-emitting chip to ensure that after the encapsulation film is attached to the display substrate, a portion of the adhesive layer 30 can be located on a layer of the light-emitting chip away from the substrate, thereby protecting the LED light-emitting chip without damaging the LED light-emitting chip or damaging the diffusion particle layer 90. In one example, the difference between the thickness of the adhesive layer 30 and the height of the LED light-emitting chip is between 10 and 100 μm, for example, between 10 and 30 μm, or between 20 and 50 μm, or between 50 and 70 μm.

[0100] For example, the difference between the thickness of the adhesive layer 30 and the height of the LED light emitting chip is at least 16 micrometers. Taking the height of the LED light emitting chip as 80 micrometers as an example, the thickness of the adhesive layer 30 is greater than or equal to 96 micrometers.

[0101] In some embodiments, as shown in FIG6 , when the packaging film includes a diffusion particle layer 90 , it may also include the surface treatment layer 80 , so that the packaging film can achieve at least one of the effects of anti-fouling, reduced reflection, and anti-glare.

[0102] In the embodiments shown in Figures 7 to 9 , the encapsulating film material includes a plastic film 100 and an adhesive layer 30 located on one side of the plastic film 100. The plastic film 100 includes a first plastic layer 10 and a second plastic layer 20 stacked together. For example, the adhesive layer is located on the side of the first plastic layer 10 away from the second plastic layer 20.

[0103] In some embodiments, as shown in Figures 7 and 8 , one of the first plastic layer 10 and the second plastic layer 20 is a transparent film TF, and the other is a dark film DF. Both the dark film DF and the transparent film TF are plastic layers, requiring no coating process. Furthermore, compared to the adhesive layer formed after curing glue, the plastic layer is harder, and its thickness is unaffected by the extrusion of the light-emitting chip. This reduces ink color fluctuations in the packaging film material, thereby improving the ink color consistency of the tiled display screen after multiple packaged display devices are tiled.

[0104] In another embodiment, as shown in Figure 9 , both the first plastic layer 10 and the second plastic layer 20 are transparent thin films (TF), with a first adhesive layer 50 located between the first and second plastic layers 10 and 20. The visible light transmittance of the first adhesive layer 50 is lower than that of the first and second plastic layers 10 and 20, resulting in a dark overall color for the encapsulation film. The first adhesive layer 50, with its high hardness, is made of plastic on both the top and bottom sides, thus protecting it from the impact of compression on the light-emitting chip on the thickness accuracy of the first adhesive layer 50. This reduces color fluctuations in the encapsulation film, thereby improving the color consistency of the resulting display screen after multiple encapsulated display devices are assembled.

[0105] In some embodiments, as shown in Figure 7 , the first plastic layer 10 is a transparent film TF, and the second plastic layer 20 is a dark film DF. A second adhesive layer 40 is also included between the first and second plastic layers 10 and 20. The visible light transmittance of the second adhesive layer 40 is greater than that of the dark film DF. When the encapsulation film material shown in Figure 7 is used to encapsulate an LED display substrate, the dark film DF is further away from the LED display substrate than the transparent film TF and second adhesive layer 40, resulting in a darker visual appearance for the encapsulated display product.

[0106] For example, the transparent film TF in FIG7 has a visible light transmittance greater than 90%, and the dark film DF has a visible light transmittance between 20% and 75%, thereby ensuring that the encapsulation film material does not affect the display of the display product, while achieving a certain visual black color effect when the display product is not displaying an image. For example, the transparent film TF has a visible light transmittance between 92% and 95%, or between 95% and 98%, or above 98%; the dark film DF has a visible light transmittance between 30% and 60%, thereby ensuring the normal display of the display product and having a good visual black color effect. For example, the dark film DF has a visible light transmittance between 30% and 40%, or between 40% and 50%, or between 50% and 60%.

[0107] Exemplarily, the transmittance of the second adhesive layer 40 in FIG. 7 to visible light is greater than or equal to 95%, so as to prevent the second adhesive layer 40 from affecting the display of the display product.

[0108] For example, in FIG7 , the material of the transparent film TF is any one of PET (polyethylene terephthalate), PC (polycarbonate), PI (polyimide), and TAC (cellulose triacetate). The dark film DF includes a substrate and carbon black particles dispersed in the substrate, and the substrate is any one of PET, PC, PI, and TAC. When the transparent film TF and the dark film DF are selected from the above materials, the transparent film TF and the dark film DF can have sufficient hardness, thereby providing sufficient mechanical strength support for the packaging film material as a whole, and will not cause the problem of ink color instability due to the LED light-emitting chip squeezing the packaging film material.

[0109] In FIG7 , the total thickness of the first plastic layer 10, the second plastic layer 20, and the second adhesive layer 40 therebetween is greater than or equal to 100 microns, thereby enhancing support for the encapsulating film. For example, the total thickness of the first plastic layer 10, the second plastic layer 20, and the second adhesive layer 40 therebetween is within a range of 100 to 300 μm, thereby enhancing support for the encapsulating film while preventing the encapsulating film from being too thick; for example, the total thickness is within a range of 100 to 150 μm, or 150 to 200 μm, or 200 to 300 μm.

[0110] Because the second adhesive layer 40 is made of a relatively soft material, the first plastic layer 10 and the second plastic layer 20 primarily provide support. To further ensure support for the encapsulation film, in some embodiments, the total thickness of the first plastic layer 10 and the second plastic layer 20 is set to be greater than or equal to 50 microns. For example, the total thickness of the first plastic layer 10 and the second plastic layer 20 is between 50 and 150 μm, such as between 50 and 100 μm, or between 100 and 150 μm.

[0111] For example, in FIG7 , the hardness of the overall structure composed of the first plastic layer 10 , the second plastic layer 20 and the second adhesive layer 40 therebetween is between 2H and 4H, thereby providing sufficient mechanical strength support for the entire packaging film material.

[0112] It should be noted that in Figures 7 to 9, the first plastic layer 10 and the second plastic layer 20 provide support for the encapsulating film. In other examples, only the thicker dark film DF can be provided, without the transparent film TF and the second adhesive layer 40. Compared to this embodiment, the advantage of providing the transparent film TF, the dark film DF, and the second adhesive layer 40 simultaneously in the above example is that the thickness of each of the three layers can be relatively small, thus facilitating control of the thickness uniformity of the film layers.

[0113] In some embodiments, the second adhesive layer 40 can be configured to scatter visible light, thereby allowing the encapsulation film to diffuse light from the LED display substrate, resulting in a uniform light output. For example, the second adhesive layer 40 can be doped with diffusing particles for scattering visible light, including but not limited to titanium dioxide particles, zirconium dioxide particles, silicon-based particles, and silicon dioxide particles.

[0114] In some embodiments, at least one of an anti-glare (AG) layer (not shown), an anti-reflection (AR) layer (not shown), and an anti-fouling (AF) layer (not shown) is provided on the side of the second plastic layer 20 away from the first plastic layer 10, thereby providing the encapsulation film with anti-glare characteristics, reduced reflection, and easy-to-wipe advantages. When forming the anti-glare layer, for example, an anti-glare surface can be formed by embossing a microstructure on the second plastic layer 20. Alternatively, the anti-glare layer can be formed on the side of the second plastic layer 20 away from the first plastic layer 10 to provide the encapsulation film with anti-glare characteristics.

[0115] The anti-reflection layer can be formed by coating, and the anti-fouling layer can be formed by coating the second plastic layer 20 .

[0116] In practical applications, one or more of an anti-glare layer, an anti-reflection layer, and an anti-fouling layer can be provided on the second plastic layer 20, thereby enabling the encapsulation film layer to achieve one or more of the following effects: anti-glare, reduced reflection, and anti-fouling. The anti-glare effect can be achieved by providing an anti-glare layer or by treating the surface of the second plastic layer 20 to form an anti-glare surface.

[0117] It should be noted that when the anti-glare layer is a coating attached to the second plastic layer 20, the thickness of the second plastic layer 20 refers to the thickness of the second plastic layer 20 itself, and does not include the thickness of the anti-glare layer. If the anti-glare layer is obtained by surface treating the second plastic layer 20, the thickness of the second plastic layer 20 refers to the thickness of the second plastic layer 20 after the surface treatment.

[0118] In some embodiments, the adhesive layer 30 in FIG. 7 may include a matrix and scattering particles distributed within the matrix. The scattering particles are used to scatter visible light, thereby allowing the encapsulation film to diffuse the light from the LED display substrate, producing a uniform light output effect. The scattering particles include, but are not limited to, titanium dioxide particles, zirconium dioxide particles, and silicon-based particles. The particle size of these particles can be greater than or equal to 4 μm and less than or equal to 6 μm, for example, 5 μm.

[0119] The matrix of the adhesive layer 30 is a transparent optical adhesive, such as a silicon-based optical adhesive or epoxy resin.

[0120] For example, the adhesive layer 30 may further include a black pigment in the matrix, thereby adjusting the transmittance and ink color of the entire packaging film material. The black pigment may be carbon black particles.

[0121] In some embodiments, the matrix can be a UV-cured product or a thermally cured product. Before curing, the UV (Ultraviolet) particles or thermally cured particles provided in the matrix are cured after the matrix containing these particles undergoes a curing treatment (UV irradiation or thermal treatment), thereby hardening the matrix of the adhesive layer 30 as a whole, eliminating uncured parts, and reducing the creep by approximately 50%, thereby greatly reducing adhesion during assembly and disassembly. The above-mentioned curing treatment is the process of converting a substance (a matrix containing UV particles or thermally cured particles) from a low molecular weight to a high molecular weight (a substance generated after curing). Taking UV curing as an example, the principle can be as follows: UV particles are photosensitivity, and under UV light irradiation, they are photo-initiated to form excited ecological molecules, which decompose into free radicals or ions, causing unsaturated organic matter to undergo chemical reactions such as polymerization, grafting, and cross-linking to achieve the purpose of curing.

[0122] In some examples, the adhesive layer 30 in FIG. 7 can be a single layer structure comprising a matrix and scattering particles and / or black pigment within the matrix. In other examples, the adhesive layer 30 in FIG. 7 can be a composite layer, for example, comprising a diffusion layer and a transparent adhesive layer stacked together, with the transparent adhesive layer located on the side of the diffusion layer away from the first plastic layer 10, and the diffusion layer comprising the matrix and the scattering particles and / or black pigment within the matrix. The thickness of the adhesive layer 30 can be determined based on the height of the LED chip. The LED chip is disposed on the substrate, and the height of the LED chip is the vertical distance from the surface of the LED chip away from the substrate to the substrate. For example, the thickness of the adhesive layer 30 can be greater than or equal to the height of the LED chip, ensuring that after lamination and curing of the adhesive layer 30 with the substrate on which the LED chip is disposed, a portion of the adhesive layer 30 is located on the side of the LED chip away from the substrate. Prior to lamination, the thickness of the adhesive layer 30 is greater than the height of the LED chip, ensuring that after lamination, the adhesive layer 30 on the side of the LED chip away from the substrate has a thickness of at least 5 microns. For example, the difference between the thickness of the adhesive layer 30 and the height of the LED light emitting chip is between 0 and 50 μm, thereby ensuring that after lamination, the thickness of the adhesive layer 30 on the side of the LED light emitting chip away from the substrate is between 10 and 100 μm.

[0123] In one example, the height of the LED light emitting chip is between 80 and 120 μm, and the thickness of the adhesive layer 30 is between 80 and 170 μm.

[0124] In other embodiments, as shown in FIG8 , the first plastic layer 10 is a dark film DF, and the second plastic layer 20 is a transparent film TF. A second adhesive layer 40 is further provided between the first plastic layer 10 and the second plastic layer 20. The second adhesive layer 40 has a visible light transmittance greater than that of the dark film DF.

[0125] When the packaging film material shown in FIG8 is used to package the LED display substrate, the transparent film TF is located on the upper layer, and its reflection of the ambient light is relatively uniform. Therefore, after the packaged LED display substrates are spliced ​​into a large-sized spliced ​​display screen, the difference in the reflected and heat-dissipated light energy between the splicing seam and the display area of ​​the LED display panel is not much, thereby improving the overall display effect of the spliced ​​display screen.

[0126] Similar to Figure 7 , in Figure 8 , the transparent film TF has a visible light transmittance greater than 90%, while the dark film DF has a visible light transmittance between 20% and 75%. This ensures that the encapsulating film material does not affect the display of the display product, while achieving a certain visual black color effect when the display product is not displaying an image. For example, the transparent film TF has a visible light transmittance between 92% and 95%, or between 95% and 98%, or above 98%. The dark film DF has a visible light transmittance between 30% and 60%, thereby ensuring the normal display of the display product and achieving a good visual black color effect. For example, the dark film DF has a visible light transmittance between 30% and 40%, or between 40% and 50%, or between 50% and 60%.

[0127] Exemplarily, the transmittance of the second adhesive layer 40 in FIG. 8 to visible light is greater than or equal to 95%, so as to prevent the second adhesive layer 40 from affecting the display of the display product.

[0128] For example, in Figure 8 , the transparent film TF is made of any one of PET, PC, PI, and TAC. The dark film DF comprises a substrate, which is any one of PET, PC, PI, and TAC, and carbon black particles dispersed within the substrate. When the transparent film TF and the dark film DF are selected from the aforementioned materials, they possess sufficient hardness, thereby providing sufficient mechanical strength for the overall packaging film material and preventing issues with ink color instability caused by the LED light-emitting chip squeezing the packaging film material.

[0129] Similar to FIG7 , in FIG8 , the total thickness of the first plastic layer 10, the second plastic layer 20, and the second adhesive layer 40 therebetween is greater than or equal to 100 microns, thereby enhancing support for the encapsulating film. For example, the total thickness of the first plastic layer 10, the second plastic layer 20, and the second adhesive layer 40 therebetween is within a range of 100 to 300 μm, thereby enhancing support for the encapsulating film while preventing the encapsulating film from being too thick; for example, the total thickness is within a range of 100 to 150 μm, or 150 to 200 μm, or 200 to 300 μm.

[0130] The total thickness of the first plastic layer 10 and the second plastic layer 20 can be set to be greater than or equal to 50 microns. For example, the total thickness of the first plastic layer 10 and the second plastic layer 20 is between 50 and 150 μm, such as between 50 and 100 μm, or between 100 and 150 μm.

[0131] The hardness of the entire structure composed of the first plastic layer 10 , the second plastic layer 20 and the second adhesive layer 40 therebetween is between 2H and 4H, thereby providing sufficient mechanical strength support for the entire packaging film material.

[0132] In Figure 8 , the side of the second plastic layer 20 facing away from the first plastic layer 10 can also be provided with at least one of the aforementioned anti-glare layer, anti-reflection layer, and anti-fouling layer. Furthermore, the second adhesive layer 40 is configured to scatter visible light. For example, scattering particles may be incorporated into the second adhesive layer 40. The specific structure and materials of the adhesive layer 30 in Figure 8 can be found in the description of Figure 7 above and will not be repeated here.

[0133] In some further embodiments, as shown in FIG9 , the first plastic layer 10 and the second plastic layer 20 are both transparent thin films TF, and a first adhesive layer 50 is provided between the first plastic layer 10 and the second plastic layer 20. The transparent thin film TF is made of any one of PET, PC, PI, and TAC to ensure that the transparent thin film TF has sufficient hardness, thereby providing sufficient mechanical support strength for the encapsulation film material.

[0134] The first adhesive layer 50 comprises an adhesive layer base and a black pigment within the base. The adhesive layer base can be made of a transparent optical adhesive, such as a silicone-based optical adhesive or epoxy resin. In practice, the transmittance and ink color of the second adhesive layer 40 can be adjusted by adjusting the amount of black pigment incorporated, thereby adjusting the transmittance and ink color of the entire packaging film.

[0135] For example, in the packaging film material shown in Figure 9, the first adhesive layer 50 can be configured to scatter visible light. For example, the first adhesive layer 50 can also include scattering particles, and the scattering particles are used to scatter visible light, so that the packaging film material can scatter the light of the LED display substrate to produce a uniform light output effect.

[0136] Exemplarily, the overall transmittance of the first plastic layer 10, the second plastic layer 20 and the first adhesive layer 50 to visible light is in the range of 30% to 60%, so that the packaging film material does not affect the display of the display product, and at the same time achieves a certain visual ink effect when the display product does not display the picture.

[0137] In the packaging film shown in FIG9 , the first plastic layer 10 and the second plastic layer 20 both have a visible light transmittance greater than 90%, for example, greater than 92%, or greater than 95%, or greater than 97%. The first adhesive layer 50 has a visible light transmittance in the range of 20% to 75%. Optionally, the first adhesive layer 50 has a visible light transmittance in the range of 30% to 60%, thereby ensuring normal display of the display product and providing a good visual ink color effect. For example, the visible light transmittance of the first adhesive layer 50 is between 30% and 40%, or between 40% and 50%, or between 50% and 60%.

[0138] Similar to Figure 7 , in the packaging film shown in Figure 9 , the total thickness of the first plastic layer 10, the second plastic layer 20, and the first adhesive layer 50 therebetween is greater than or equal to 100 microns, thereby enhancing the support provided to the packaging film. For example, the total thickness of the first plastic layer 10, the second plastic layer 20, and the second adhesive layer 40 therebetween is within a range of 100 to 300 μm, thereby enhancing the support provided by the packaging film while preventing the packaging film from being excessively thick; for example, between 100 and 150 μm, or between 150 and 200 μm, or between 200 and 300 μm. Similar to Figure 7 , in Figure 9 , the total thickness of the first plastic layer 10 and the second plastic layer 20 is set to be greater than or equal to 50 microns. For example, the total thickness of the first plastic layer 10 and the second plastic layer 20 is between 50 and 150 μm.

[0139] For example, the hardness of the entire structure composed of the first plastic layer 10 , the second plastic layer 20 and the first adhesive layer 50 therebetween is between 2H and 4H, thereby providing sufficient mechanical strength support for the entire packaging film material.

[0140] In the packaging film shown in FIG9 , the surface of the second plastic layer 20 facing away from the first plastic layer 10 can also be provided with at least one of an anti-glare layer, an anti-reflection layer, and an anti-fouling layer, as described above. Furthermore, the specific structure and materials of the adhesive layer 30 in FIG9 can be found in the description of FIG7 above and will not be repeated here.

[0141] FIG10A is a schematic diagram of an encapsulation film material provided in yet other embodiments of the present disclosure. As shown in FIG10A , the encapsulation film material includes a laminated adhesive layer 30 and a plastic film 100. The plastic film 100 includes a first plastic layer 10 and a dark film DF. The dark film DF can be attached to a surface of the first plastic layer 10 close to the adhesive layer 30 or a surface away from the adhesive layer 30. FIG10A only illustrates an example in which the dark film DF is attached to a surface of the first plastic layer 10 away from the adhesive layer 30.

[0142] In one example, the first plastic layer 10 is a transparent plastic layer, and its transmittance is as described above for the transparent film TF. The dark film DF may be made of a black dye. For example, the dark film may be an ink coating, and its thickness may be less than or equal to 10 μm, for example, between 3 and 5 μm.

[0143] In one example, the transmittance of the dark film DF and the first plastic layer 10 to visible light as a whole is in the range of 30% to 60%; and the total thickness of the dark film DF and the first plastic layer 10 is in the range of 50 to 150 μm.

[0144] In one example, the thickness of the first plastic layer 10 is greater than or equal to 50 microns to ensure that the packaging film can provide sufficient mechanical strength support. For example, the thickness of the first plastic layer 10 is 50 microns, or 60 microns, or 70 microns, or 80 microns, or 90 microns.

[0145] In one example, the hardness of the overall structure of the first plastic layer 10 and the dark film DF is between 2H and 4H, thereby providing sufficient mechanical strength support for the packaging film material as a whole.

[0146] In FIG10A , the first plastic layer 10 and the dark film DF, formed as a whole, can be provided with at least one of an anti-glare surface, an anti-reflection layer, and an anti-fouling layer on a layer away from the adhesive layer 30. The specific structure and materials of the adhesive layer 30 can be found in the description of FIG7 above and will not be repeated here.

[0147] FIG10B is a schematic diagram of an encapsulation film material provided in some other embodiments of the present disclosure. As shown in FIG10B , the encapsulation film material includes a laminated adhesive layer 30 and a plastic film 100. The plastic layer 100 includes a first sublayer 101 and a second sublayer 102. The first sublayer 101 is a transparent plastic layer, and the second sublayer 102 is a dyed layer, which serves as the aforementioned dark film DF. In one example, the second sublayer 102 and the first sublayer 101 form an integral structure. The second sublayer 102 is formed by dyeing the transparent plastic layer. That is, the second sublayer 102 includes a transparent plastic substrate and dye particles located in the transparent plastic substrate. The dye particles include, for example, carbon black particles.

[0148] It should be noted that FIG10B is illustrated by taking the example of the second sub-layer 102 being located on the side of the first sub-layer 101 away from the adhesive layer 30 . The second sub-layer 102 may also be located on the side of the first sub-layer 101 close to the adhesive layer 30 .

[0149] The first sublayer 101 of the plastic film 100 may have a visible light transmittance greater than 90%, and the second sublayer 102 may have a visible light transmittance within a range of 20% to 75%, for example, 30% to 60%. The material of the first sublayer 101 may be any of the aforementioned PET, PC, PI, and TAC.

[0150] In some examples, the total thickness of the first sub-layer 101 and the second sub-layer 102 is greater than or equal to 50 μm, thereby providing effective support for the packaging film material. For example, the total thickness of the first sub-layer 101 and the second sub-layer 102 is between 50 and 150 μm.

[0151] In one example, in FIG. 10B , the hardness of the entire plastic film 100 is between 2H and 4H, thereby providing sufficient mechanical strength support for the entire packaging film material.

[0152] In FIG. 10B , at least one of an anti-glare layer, an anti-reflection layer, and an anti-fouling layer may be provided on the entire surface of the plastic film 100 away from the adhesive layer 30 .

[0153] In FIG10B , the specific structure and material of the adhesive layer 30 may refer to the above description of FIG7 , which will not be repeated here.

[0154] In the packaging film materials provided in each embodiment, by controlling the material and thickness of each film layer, the transmittance of the overall packaging film material to visible light can be within the range of 20% to 75%, for example, within the range of 30% to 60%, and the L value of the overall packaging film material in the LAB space can be less than 31.5, for example, between 28 and 30.

[0155] Figures 11A to 11D are various schematic diagrams of the display substrate provided in some embodiments of the present disclosure. As shown in Figures 11A to 11D, the display substrate includes a base 61, an LED light-emitting chip 62 arranged on the base 61, and a packaging film material. The packaging film material adopts the packaging film material in any of the above embodiments. The LED chip is located between the base 61 and the packaging film material, and is located on the side of the adhesive layer 30 away from the plastic film.

[0156] In some embodiments, the substrate 61 may be a PCB board or a glass board.

[0157] In some embodiments, the LED light emitting chip 62 is a mini-LED chip or a micro-LED chip.

[0158] As shown in Figures 11A to 11D , the adhesive layer 30 includes a first functional portion 31 and a second functional portion 32. The first functional portion 31 is located between the LED light-emitting chip 62 and the plastic film 100, and the second functional portion 32 is located between adjacent LED light-emitting chips 62. The first functional portion 31 and the second functional portion 32 are in contact with each other. In this case, the thickness of the second functional portion 32 is greater than that of the LED light-emitting chip 62 to achieve contact between the first functional portion 31 and the second functional portion 32. In this way, each LED light-emitting chip 62 can be completely covered by the first functional portion 31 and the second functional portion 32, thereby better protecting the LED light-emitting chip 62 and preventing the LED light-emitting chip 62 from being squeezed and damaged.

[0159] In some embodiments, the first functional portion 31 and the second functional portion 32 are arranged in contact with each other, with the second functional portion 32 contacting the substrate 61 and the plastic film 100 respectively; while the first functional portion 31 contacts the LED light-emitting chip 62 and the plastic film 100 respectively. In this case, the thickness of the second functional portion 32 is equal to or approximately equal to the sum of the thicknesses of the first functional portion 31 and the light-emitting chip 62. This allows the first and second functional portions 31 and 32 to completely fill the space between the first plastic film 10 and the substrate 61, thereby better protecting the LED light-emitting chip 62.

[0160] In some embodiments, multiple LED light-emitting chips 62 are separated by the second functional part 32, and the LED light-emitting chips 62 are in direct contact with the second functional part 32. In this way, the second functional part 32 can protect the LED light-emitting chip 62 at the periphery of the LED light-emitting chip 62 to prevent the LED chip from being squeezed and damaged by contact with the first plastic film 10 after the packaging film material encapsulates the LED light-emitting chip 62.

[0161] In some embodiments, the orthographic projection of the first functional portion 31 on the plane of the first plastic film 10 covers the center of the orthographic projection of the light-emitting area of ​​the light-emitting chip 62 on the plane of the plastic film 100. The first functional portion 31 can partially cover the light-emitting area of ​​the LED light-emitting chip 62, that is, cover the center of the light-emitting area, thereby improving the light output effect of the display substrate.

[0162] In some embodiments, the orthographic projection of the first functional portion 31 on the plane of the first plastic film 10 covers the orthographic projection of the light emitting area of ​​the LED light emitting chip 62 on the plane of the plastic film 100. The first functional portion 31 may completely cover the light emitting area of ​​the LED light emitting chip 62.

[0163] In some embodiments, as shown in FIG. 11A and FIG. 11C , the adhesive layer 30 may be a single-layer structure, and the first functional portion 31 and the second functional portion 32 are made of the same material. For details about the materials of the first and second functional portions, refer to the description of the adhesive layer 30 above.

[0164] In other embodiments, as shown in FIG11B , the adhesive layer 30 may also be a composite layer formed of a multilayer structure. For example, the adhesive layer 30 includes a transparent adhesive layer 30a and a diffusion layer 30b stacked together. The diffusion layer 30b is located on the side of the transparent adhesive layer 30a away from the substrate 61. The visible light transmittance of the transparent adhesive layer 30a may be greater than 90%. The diffusion layer 30b includes the aforementioned matrix layer and scattering particles and / or black pigment located in the matrix layer.

[0165] When the adhesive layer 30 is a composite layer, a portion of the diffusion layer 30b is located on the side of the LED light-emitting chip 62 away from the substrate 61. The relationship between the thickness of the transparent adhesive layer 30a and the height of the LED light-emitting chip 62 is not limited. Specifically, as shown in FIG11B , the second functional portion 32 includes a portion of the diffusion layer 30b and a portion of the transparent adhesive layer 30a, while the first functional portion 31 includes a portion of the diffusion layer 30b and a portion of the transparent adhesive layer 30a. Alternatively, the first functional portion 31 may include only a portion of the diffusion layer 30b.

[0166] In yet other embodiments, as shown in FIG11D , a diffusion particle layer 90 is further disposed between the adhesive layer 30 and the plastic film. The adhesive layer 30 includes a first functional portion 31 and a second functional portion 32. The first functional portion 31 is located between the LED light-emitting chip 62 and the first plastic film 10, and the second functional portion 32 is located between adjacent LED light-emitting chips 62. The first functional portion 31 and the second functional portion 32 are in contact with each other. In this case, the first functional portion 31 and the second functional portion 32 both include a portion of the diffusion particle layer 90 and a portion of the adhesive layer 30. Of course, the first functional portion 31 may also include only a portion of the diffusion particle layer 90.

[0167] In some embodiments, as shown in Figures 11A to 11D , the adhesive layer 30 conforms to the surface of the substrate 61 facing the packaging film and the assembled LED light-emitting chips 62. In other words, if the substrate 61 and the structure formed by the multiple LED light-emitting chips 62 assembled thereon are considered to be the light board 60, then the surface of the adhesive layer 30 facing the light board 60 and the surface of the light board 60 as a whole facing the packaging film are conformal.

[0168] In this case, the adhesive layer 30 can be formed on the light board 60 by lamination. Specifically, a functional material (in this case, a deformable gel) is formed on the surface of the plastic film 100. During lamination, the entire lamination chamber is first evacuated. Then, air is introduced into the chamber, facing away from the substrate, to create an air pressure differential on both sides of the encapsulating film. This pressure differential allows the encapsulating film to be pressed onto the light board 60. The vacuum lamination process is illustrated in Figure 12. The functional material on the surface of the LED chip 62 facing away from the substrate 61 is squeezed and overflows between two adjacent LED chips 62, resulting in the functional material layer's surface facing the substrate 61 conforming to the surface of the light board 60 facing the functional material layer. The functional material is then cured, forming the adhesive layer 30 conforming to the surface of the light board 60 facing the encapsulating film. The remaining material on the surface of the LED chip 62 facing away from the substrate 61 forms the first functional portion 31, while the area between two adjacent LED chips 62 forms the second functional portion 32.

[0169] In some embodiments, the thickness of the cured adhesive layer 30 is greater than the height of the LED light-emitting chip 62. A portion of the adhesive layer 30 can be located on the side of the LED light-emitting chip away from the substrate, thereby protecting the LED light-emitting chip. In one example, the difference between the thickness of the adhesive layer 30 and the height of the LED light-emitting chip 62 is between 10 and 100 μm, for example, between 10 and 30 μm, or between 30 and 50 μm, or between 50 and 70 μm.

[0170] It is understandable that when there is no other film layer between the adhesive layer 30 and the plastic film 100 , the difference between the thickness of the adhesive layer 30 and the height of the LED light-emitting chip 62 is the thickness of the first functional portion 31 .

[0171] In some embodiments, as shown in Figures 11A to 11D, the surface of the plastic film 100 facing the substrate 61 is parallel to the substrate 61, that is, the surface of the plastic film 100 facing the substrate 61 is a flat surface and does not fluctuate with the adhesive layer 30, thereby providing a stable supporting effect.

[0172] In some embodiments, as shown in FIG11D , when the packaging film includes a diffusion particle layer 90, the surface of the diffusion particle layer 90 facing the substrate 61 is parallel to the substrate. In practical applications, the diffusion particle layer 90 is fully cured before the packaging film is attached to the substrate 61, so that the surface of the diffusion particle layer 90 facing the substrate 91 is parallel to the substrate 91. This improves the product's anti-collision properties and prevents the diffusion particle layer 90 from being squeezed by the LED light-emitting chip 62 during the attachment process, resulting in uneven distribution of the diffusion particles.

[0173] The inventors have discovered that when the thickness of the packaging film material is too large, a color seam problem is likely to occur. The causes of the color seam problem are described below.

[0174] Figure 13 is a schematic diagram of a display substrate under normal display conditions. As shown in Figure 13, the multiple LED light-emitting chips 62 on the display substrate include multiple red chips 62r, multiple green chips 62g, and multiple blue chips 62b. The multiple LED light-emitting chips 62 form multiple light-emitting chip groups, each of which includes a red chip 62r, a green chip 62g, and a blue chip 62b. When the human eye observes the display, the light emitted by the LED light-emitting chips must be emitted from the surface of the packaging film 1a to reach the human eye. Therefore, the LED light-emitting chips in the middle can be considered normal display pixels. That is, the emitted light must be less than the total reflection angle of the packaging film 1a to be emitted from the surface of the packaging film 1a. Light greater than the total reflection angle will be transmitted within the packaging film 1a until all energy is lost. For the LED light-emitting chips at the edge to display normally, the light emitted by the LED light-emitting chips less than the total reflection angle can be emitted from the surface of the packaging film 1a and cannot reach the side of the packaging film 1a. In other words, the theoretical formula (D / H1) ≥ tan(arcsin(1 / n)) is satisfied. D is the minimum horizontal distance between the LED chip 62 and the edge of the packaging film 1a. This minimum horizontal distance refers to the minimum distance between the LED chip 62 and the edge of the packaging film 1a in a direction parallel to the substrate. D is less than or equal to the distance between adjacent groups of light-emitting chips. H1 is the maximum distance between the surface of the packaging film 1a away from the substrate 61 and the substrate 61. n is the average refractive index of the packaging film.

[0175] Figures 14 and 15 are schematic diagrams of the optical path that causes color seams. Figure 14 is a schematic diagram of the principle of generating a cyan seam, and Figure 15 is a schematic diagram of the principle of generating a blue seam. When H1 and D do not satisfy the above theoretical formula, that is, when the light that needs to be emitted from the upper surface of the packaging film material 1a reaches the side of the packaging film material 1a first, an optical path abnormality will occur. Depending on the side surface of the packaging film material 1a, if the side surface is relatively rough or painted black, the light will be scattered or absorbed, reducing the energy in the original normal emission direction. When viewed from the direction of the red chip, the red light is lost, forming a cyan seam. If the side surface is relatively smooth, the light will be fully reflected by the side surface, reducing the energy in the original normal emission direction and strengthening it in the reverse direction. When viewed from the direction of the red chip, the blue light is enhanced, forming a blue seam.

[0176] From the optical path analysis, it can be seen that to solve the color gap problem, when the average refractive index n of the packaging film material is constant, the relationship between D and H1 must satisfy the theoretical formula, ensuring that light exits from the top surface of the packaging film material and not from the sides. When D is small, H1 needs to be correspondingly small. The formula shows that the viewing angle θ at which the color gap is observed is ≥ arcsin(n*sin(arctan(D / H1))). To completely eliminate the color gap, that is, to achieve a viewing angle θ of 90°, H1 ≤ 1.12*D when n = 1.5, and H1 ≤ 1.31D when n = 1.65. For example, in a specific example, D = 183.8 microns, n = 1.5, and H1 ≤ 205.5 microns, when the packaging film material adopts the structure shown in Figure 3, for example, with the plastic film 100 thickness set to 65 microns and the adhesive layer thickness set to 125 microns, the color gap requirement can be met.

[0177] H1 ≤ 1.12*D is only an example. In actual applications, H1 ≤ A*D. A is between 1.12 and 1.31. n is between 1.5 and 1.65. When n = 1.5, A is 1.12; when n = 1.65, A = 1.31.

[0178] It should be noted that when the encapsulating film material includes the adhesive layer 30 and the plastic layer 100, the refractive indices of the plastic layer 100 and the adhesive layer 30 are similar. For example, the plastic film 100 uses a PET substrate, and the matrix of the adhesive layer 30 uses an acrylic resin; the refractive indices of both are approximately 1.5. For another example, the plastic film 100 uses a PI substrate, and the matrix of the adhesive layer 30 uses an epoxy resin, and the refractive indices of both are approximately 1.65. Therefore, in actual calculations, n can be approximately considered to be the refractive index of the matrix of the adhesive layer 30 (excluding the diffusion particles), which has little actual impact on the relationship between H1 and D.

[0179] In addition, it should be noted that the viewing angle refers to the angle between the viewing direction and the thickness direction of the packaging film layer.

[0180] In some embodiments, the thickness of the plastic film 100 is greater than or equal to 50 microns to ensure the support effect of the packaging film material. When the diffusion particles are evenly distributed in the adhesive layer 30, the thickness of the adhesive layer 30 is greater than or equal to 96 microns to ensure that the adhesive layer 30 is present on the side of the LED light-emitting chip 62 away from the substrate 61, preventing the LED light-emitting chip 62 from contacting the plastic film 100 and damaging the plastic film 100 or scratching the LED light-emitting chip 62.

[0181] Taking the packaging film structure shown in Figure 4 as an example, the packaging film comprises an adhesive layer 30 and a plastic film 100. A surface treatment layer 80 is provided on the side of the plastic film 100 facing away from the adhesive layer 30. Assuming the thickness of the surface treatment layer 80 is 10 microns, the total thickness of the plastic film 100 and the adhesive layer 30 must be less than or equal to 220 microns. As mentioned above, the minimum thickness of the adhesive layer 30 is 96 microns. Considering that after the packaging film is bonded to the substrate 61, the thickness of the adhesive layer 30 increases by 5 microns due to the insertion of the LED chip 62 into the adhesive layer 30, the maximum thickness of the plastic film 100 is (220 - 96 - 5) = 119 microns. Furthermore, the minimum thickness of the plastic film 100 is 50 microns to ensure support. Therefore, the maximum thickness of the adhesive layer 30 is (220 - 50 - 5) = 165 microns. In summary, the thickness of the adhesive layer 30 ranges from 96 microns to 165 microns, and the thickness of the plastic film 100 ranges from 50 microns to 119 microns.

[0182] In some embodiments, when the encapsulation film material includes a diffusion particle layer 90 positioned between the adhesive layer 30 and the plastic film 100, the thickness of the diffusion particle layer 90 is greater than or equal to 26 microns. If the thickness of the diffusion particle layer 90 is too thin, the concentration of the diffusion particles must be increased to ensure a diffusion effect, which can lead to unstable film coating. In the disclosed embodiments, the thickness of the diffusion particle layer 90 is set to be greater than or equal to 26 microns, which can improve coating stability and ensure a diffusion effect.

[0183] Taking the packaging film material with the structure shown in Figure 6 as an example, the packaging film material includes an adhesive layer 30, a plastic film 100, and a diffusion particle layer 90 located between the adhesive layer 30 and the plastic film 100. A surface treatment layer 80 is provided on the side of the plastic film 100 away from the adhesive layer 30. Assuming that the thickness of the surface treatment layer 80 is 10 microns, the total thickness of the plastic film 100, the adhesive layer 30, and the diffusion particle layer 90 needs to be less than or equal to 220 microns. As mentioned above, the minimum thickness of the plastic film 100 is 50 microns to ensure the support effect of the packaging film material; the minimum thickness of the adhesive layer 30 is 96 microns to prevent the LED light-emitting chip 62 from contacting the plastic film 100 and damaging the plastic film 100 or scratching the LED light-emitting chip 62; in addition, considering that after the packaging film material is bonded to the substrate, the LED light-emitting chip 62 is inserted into the adhesive layer 30, resulting in an increase of 5 microns in thickness of the adhesive layer 30, the maximum thickness of the diffusion particle layer 90 can be set to (220-96-5-50)=6 9 microns; when the minimum thickness of the diffusion particle layer 90 is 26 microns and the minimum thickness of the adhesive layer 30 is 96 microns, and considering that the thickness of the adhesive layer 30 increases by 5 microns after lamination, the maximum thickness of the plastic layer can be set to (220-26-96-5) = 93 microns; when the minimum thickness of the plastic layer is 50 microns and the minimum thickness of the diffusion particle layer 90 is 26 microns, and considering that the thickness of the adhesive layer 30 increases by 5 microns after lamination, the maximum thickness of the adhesive layer 30 can be set to (220-50-26-5) = 139 microns. In summary, the thickness range of the adhesive layer 30 is 96 microns to 139 microns; the thickness range of the diffusion particle layer 90 is 26 microns to 69 microns; and the thickness range of the plastic layer is 50 microns to 93 microns.

[0184] FIG11E is a schematic diagram of a display substrate provided in some other embodiments of the present disclosure. As shown in FIG11E , the display substrate includes a base 61, an LED light-emitting chip 62 located on the base 61, and an encapsulation film. In FIG11E , the encapsulation film includes an adhesive layer 30 and a plastic film 100. The plastic film 100 includes only a transparent thin film TF. The transparent thin film TF has a visible light transmittance of greater than 85%, for example, between 85% and 90%, or between 90% and 95%, or greater than 95%.

[0185] In some embodiments, the adhesive layer 30 of FIG11E may include diffusion particles for scattering light. Detailed descriptions can be found in the above description of FIG3 , which will not be repeated here.

[0186] In some embodiments, the plastic film 100 in FIG. 11E may be provided with a surface treatment layer 80 on the side facing away from the substrate 61. This surface treatment layer 80 may include one or more of the anti-glare layer, anti-reflection layer, and anti-fouling layer described above. Of course, to achieve an anti-glare effect, the surface of the plastic film 100 may also be treated to create a roughened surface with an anti-glare effect on the surface facing away from the adhesive layer 30. For details, see the description of FIG. 4 above.

[0187] In Figure 11E , a dark coating 63, such as an ink coating, is applied to the surface of substrate 61 facing the encapsulating film. Dark coating 63 includes an opening, where LED chip 62 is located. In this manner, the display substrate achieves a high transmittance and a visually appealing ink-like effect when not displaying an image. The material of dark coating 63 may include, for example, carbon black or the black matrix material commonly used in color filter substrates for liquid crystal display panels.

[0188] In Figure 11E , the thickness of the packaging film can also be less than or equal to A*D to prevent color seam issues. Similar to the packaging film in Figure 4 , in Figure 11E , the thickness of the adhesive layer 30 is greater than or equal to 96 microns, and the thickness of the plastic film 100 is greater than or equal to 50 microns. For example, the thickness of the adhesive layer 30 ranges from 96 microns to 165 microns, and the thickness of the plastic film 100 ranges from 50 microns to 119 microns.

[0189] An embodiment of the present disclosure further provides a display module, comprising a plurality of display substrates arranged in an array, wherein the display substrates are the display substrates of any of the above embodiments.

[0190] It should be noted that in order to reduce the stitching seams in the display screen, the stitching seam gap between the display substrates should be as small as possible, wherein the minimum horizontal distance D and gap between the LED light-emitting chip 62 and the edge of the packaging film material 1a can satisfy: the value of 2*D+gap is less than or equal to the distance between two adjacent light-emitting chip groups on a display substrate in the direction of the minimum horizontal distance D from the LED light-emitting chip 62 to the edge of the packaging film material 1a.

[0191] The present disclosure also provides a method for packaging a display substrate, wherein the display substrate includes a substrate and an LED light-emitting chip located on the substrate. The method for packaging the display substrate includes:

[0192] S1. Provide a packaging film material, which is the packaging film material in the above embodiment.

[0193] S2. Press the packaging film material onto the display substrate, with a portion of the adhesive layer located between the LED light-emitting chip and the plastic film, and another portion located between adjacent LED light-emitting chips.

[0194] After lamination and curing, the portion of the adhesive layer between the LED light-emitting chip and the plastic film is the first functional portion, and the portion of the adhesive layer between adjacent LED light-emitting chips is the second functional portion. The lamination process can be a vacuum lamination process, as described above, and will not be repeated here.

[0195] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A packaging film material for packaging LED display substrates, wherein: The packaging film material includes a plastic film and a glue layer located on one side of the plastic film; Wherein, the plastic film comprises a dark film, and the transmittance of the dark film to visible light is in the range of 30% to 60%.

2. The packaging film material according to claim 1, wherein: The plastic film only includes the dark film; the material of the dark film is a substrate doped with black dye, and the material of the substrate is any one of PET, PC, PI, and TAC. 3 . The packaging film material according to claim 2 , wherein the thickness of the plastic film is greater than or equal to 50 μm.

4. The packaging film material according to claim 1, wherein: The plastic film, the dark thin layer and the transparent plastic layer, the dark thin layer being attached to the transparent plastic layer; The material of the dark thin layer is black dye.

5. The packaging film material according to claim 4, wherein: The thickness of the transparent plastic layer is greater than or equal to 50 microns.

6. The packaging film material according to any one of claims 1 to 5, wherein: The adhesive layer includes diffusion particles, and the diffusion particles are used for scattering light.

7. The packaging film material according to claim 6, wherein: The material of the diffusion particles is at least one of silicon dioxide and titanium dioxide.

8. The packaging film material according to claim 6, wherein: The diffusion particles are evenly distributed in the adhesive layer.

9. The packaging film material according to any one of claims 1 to 5, wherein: The packaging film material comprises a diffusion particle layer located between the glue layer and the plastic film, and the diffusion particle layer is used for scattering light.

10. The packaging film material according to any one of claims 1 to 5, wherein: The surface of the plastic film away from the adhesive layer is provided with at least one of an anti-glare layer, an anti-reflection layer and an anti-fouling layer; Wherein, the anti-glare layer is a coating layer attached to the surface of the plastic film, or the anti-glare layer is obtained by treating the surface of the plastic film.

11. The packaging film material according to claim 1, wherein: The plastic film comprises a first plastic layer and a second plastic layer which are stacked; Wherein, one of the first plastic layer and the second plastic layer is a transparent film, and the other is the dark film; or, The first plastic layer and the second plastic layer are both transparent films, and a first adhesive layer is included between the first plastic layer and the second plastic layer, and the first adhesive layer is the dark film.

12. The packaging film material according to claim 11, wherein: The first plastic layer is a transparent film, and the second plastic layer is the dark film, or the first plastic layer is the dark film, and the second plastic layer is a transparent film; A second adhesive layer is further included between the first plastic layer and the second plastic layer, and the transmittance of the second adhesive layer to visible light is greater than the transmittance of the dark film to visible light.

13. The packaging film material according to claim 12, wherein: The transparent film has a visible light transmittance greater than 90%.

14. The packaging film material according to claim 13, wherein: The visible light transmittance of the second adhesive layer is greater than or equal to 95%.

15. The packaging film material according to claim 12, wherein: The material of the transparent film is any one of PET, PC, PI, and TAC; the dark film includes a substrate and carbon black particles dispersed in the substrate, and the material of the substrate is any one of PET, PC, PI, and TAC.

16. The packaging film material according to claim 15, wherein: The total thickness of the first plastic layer, the second plastic layer and the second adhesive layer is between 100 and 300 μm.

17. The packaging film material according to claim 12, wherein: The second adhesive layer is configured to scatter visible light.

18. The packaging film material according to claim 11, wherein: The first plastic layer and the second plastic layer are both transparent films, and the material of the transparent films is any one of PET, PC, PI, and TAC; The first adhesive layer includes an adhesive layer matrix and a black pigment located in the matrix. The material of the adhesive layer matrix includes silicon-based optical glue or epoxy resin.

19. The packaging film material according to claim 18, wherein: The transmittance of the first plastic layer, the second plastic layer and the first adhesive layer to visible light as a whole is in the range of 30% to 60%.

20. The packaging film material according to claim 18, wherein: The total thickness of the first plastic layer, the second plastic layer and the first adhesive layer is between 100 and 300 μm.

21. The packaging film material according to claim 15 or 18, wherein: The total thickness of the first plastic layer and the second plastic layer is between 50 and 150 μm.

22. The packaging film material according to any one of claims 11 to 20, wherein: The first adhesive layer is configured to scatter visible light.

23. The packaging film material according to any one of claims 11 to 20, wherein: The surface of the second plastic layer away from the first plastic layer is provided with at least one of an anti-glare layer, an anti-reflection layer and an anti-fouling layer; Wherein, the anti-glare layer is a coating layer attached to the surface of the plastic film, or the anti-glare layer is obtained by treating the surface of the plastic film.

24. The packaging film material according to any one of claims 11 to 20, wherein: The adhesive layer includes a matrix and scattering particles distributed in the matrix, and the scattering particles are used for scattering visible light.

25. The packaging film material according to claim 24, wherein: The glue layer also includes a black pigment located within the matrix.

26. The packaging film material according to any one of claims 11 to 20, wherein: A first adhesive layer is further included between the first plastic layer and the second plastic layer, and the hardness of the first plastic layer, the second plastic layer and the first adhesive layer as a whole is within the range of 2H to 4H; or A second adhesive layer is further included between the first plastic layer and the second plastic layer, and the hardness of the first plastic layer, the second plastic layer and the second adhesive layer as a whole is in the range of 2H to 4H.

27. A display substrate, wherein: It comprises a substrate, an LED light-emitting chip located on the substrate, and a packaging film material according to any one of claims 1 to 26; Wherein, the LED light-emitting chip is located between the substrate and the packaging film material.

28. The display substrate according to claim 27, wherein: The adhesive layer includes a first part and a second part, the first part is located between the LED light-emitting chip and the first plastic layer, and the second part is located between adjacent LED light-emitting chips. The first portion and the second portion are in contact with each other.

29. The display substrate according to claim 28, wherein: The adhesive layer is integrally formed with the surface of the substrate facing the packaging film material and the LED light-emitting chip.

30. The display substrate according to claim 28, wherein: A surface of the plastic film facing the substrate is parallel to the substrate.

31. The display substrate according to claim 30, wherein: In the case where the packaging film material includes a diffusion particle layer located between the glue layer and the plastic film, a surface of the diffusion particle layer facing the substrate is parallel to the substrate.

32. The display substrate according to claim 31, wherein: The thickness of the diffusion particle layer is greater than or equal to 26 micrometers.

33. The display substrate according to claim 32, wherein: The thickness of the plastic film is greater than or equal to 50 microns; The thickness of the adhesive layer is greater than or equal to 96 microns.

34. The display substrate according to claim 32, wherein: In the case where the diffusion particles are uniformly distributed in the adhesive layer, the thickness of the plastic film is greater than or equal to 50 microns; The thickness of the adhesive layer is greater than or equal to 96 microns.

35. The display substrate according to any one of claims 27 to 34, wherein: The maximum distance H1 from the surface of the packaging film material away from the substrate to the substrate and the minimum horizontal distance D from the LED chip to the edge of the packaging film material satisfy: H1≤A*D, A is between 1.12 and 1.31; The minimum horizontal distance is the minimum distance parallel to the substrate direction.

36. The display substrate according to claim 35, wherein: H1 is less than or equal to 230 microns.

37. A display substrate, comprising a base, an LED light-emitting chip located on the base, and a packaging film material, wherein: The LED light-emitting chip is located between the substrate and the packaging film material; The packaging film material comprises a laminated adhesive layer and a plastic film, wherein the adhesive layer is located on a side of the plastic film facing the substrate, and the plastic film comprises a transparent film; a dark coating is attached to a surface of the substrate facing the packaging film material.

38. The display substrate according to claim 37, wherein: The maximum distance H1 from the surface of the packaging film material away from the substrate to the substrate and the minimum horizontal distance D from the LED chip to the edge of the packaging film material satisfy: H1≤A*D, A is between 1.12 and 1.31; The minimum horizontal distance is the minimum distance parallel to the substrate direction.

39. The display substrate according to claim 37, wherein: The adhesive layer includes diffusion particles, and the diffusion particles are used for scattering light.

40. A display module, comprising a plurality of display substrates as claimed in any one of claims 27 to 39 arranged in an array.

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