Packaging protective film, LED devices, display screens and electronic products

Abstract

The present application relates to a packaging protective film, an LED device, a display screen, and an electronic product. The packaging protective film comprises an optical film layer, a brightness enhancement film layer, a first adhesive layer, and a second adhesive layer. The optical film layer contains a light-absorbing material, the brightness enhancement film layer is disposed on the surface of the optical film layer, the first adhesive layer is disposed on the surface of the brightness enhancement film layer away from the optical film layer, the material of the first adhesive layer is OCA optical glue, the second adhesive layer is disposed on the surface of the first adhesive layer away from the brightness enhancement film layer, the material of the second adhesive layer includes OCA optical glue and polyurethane elastomer, and the polyurethane elastomer is uniformly dispersed in the second adhesive layer. The packaging protective film is used to encapsulate LED devices, can have both good appearance and high light output brightness, and is easy to debond and repair.

Description

Technical Field

[0001] The present application relates to the field of display packaging technology, and in particular to a packaging protective film, an LED device, a display screen and an electronic product. Background Art

[0002] An LED display is a flat-panel display composed of small LED module panels, used to display text, images, videos, and other information. LED electronic displays integrate microelectronics, computer technology, and information processing, offering advantages such as vibrant colors, a wide dynamic range, high brightness, long life, and stable and reliable operation.

[0003] LED displays manufactured using the COB (chip-on-board) packaging process offer advantages over those manufactured using the traditional SMT (Surface Mount Technology) packaging process, such as higher packaging efficiency and better visual quality. The packaging material used in the traditional COB packaging process typically consists of an outer polyethylene terephthalate (PET) layer and an inner OCA adhesive layer. Traditional packaging materials struggle to balance aesthetics and brightness. Furthermore, the OCA adhesive layer typically requires high-temperature baking after curing before removal, which increases the risk of adhesive residue and hinders LED display rework. Summary of the Invention

[0004] Based on this, it is necessary to provide a packaging protective film for packaging LED devices that can have both better appearance and higher light output brightness and is easy to debond and repair.

[0005] In addition, LED devices, display screens and electronic products encapsulated with the above-mentioned encapsulation protective film are also provided.

[0006] In one aspect of the present application, a packaging protective film is provided, comprising:

[0007] an optical film layer containing a light-absorbing material;

[0008] A brightness enhancement film layer, the brightness enhancement film layer being disposed on the surface of the optical film layer;

[0009] a first adhesive layer, the first adhesive layer being disposed on a surface of the brightness enhancement film layer away from the optical film layer; the first adhesive layer being made of OCA optical adhesive; and

[0010] The second adhesive layer is arranged on the surface of the first adhesive layer away from the brightness enhancement film layer; the material of the second adhesive layer includes OCA optical glue and polyurethane elastomer, and the polyurethane elastomer is uniformly dispersed in the second adhesive layer.

[0011] The encapsulation protective film provided in the embodiments of the present application includes an optical film layer, a brightness enhancement film layer, a first adhesive layer, and a second adhesive layer. The light-absorbing material in the optical film layer can control the transmittance of the encapsulation protective film, and the brightness enhancement film layer can increase the brightness of the LED light output. The first adhesive layer uses OCA optical adhesive, and the second adhesive layer is uniformly dispersed with a polyurethane elastomer. Through the rational design of each functional layer, the above-mentioned encapsulation protective film is used to encapsulate LED devices, and can ensure a high brightness of the LED light output while shielding the circuit board. The encapsulation protective film can be torn off at room temperature to facilitate subsequent repair of the LED device.

[0012] In some embodiments, the brightness enhancement film layer is made of reactive cholesteric liquid crystal.

[0013] In some embodiments, the material of the optical film layer includes one of polyethylene terephthalate, triacetyl cellulose and cycloolefin polymer.

[0014] In some embodiments, the polyurethane elastomer is colorless or formulated in black.

[0015] In some embodiments, the encapsulation protection film satisfies at least one of the following conditions (1) to (3):

[0016] (1) The encapsulation protective film further includes a surface coating; the surface coating is provided on the surface of the optical film layer away from the brightness enhancement film layer;

[0017] Optionally, the surface coating layer includes an anti-glare layer and a hardening layer; the hardening layer and the anti-glare layer are sequentially stacked on the surface of the optical film layer;

[0018] (2) The encapsulation protective film further includes a release film layer, and the release film layer is provided on a surface of the second adhesive layer away from the first adhesive layer;

[0019] (3) The light-absorbing material includes at least one of melanin and carbon black.

[0020] In another aspect of the present application, an LED device is provided, whose packaging structure is prepared using the above-mentioned packaging protective film.

[0021] In some embodiments, the LED device further includes a circuit board and an LED chip;

[0022] The LED chip is arranged on the surface of the circuit board;

[0023] The packaging structure is arranged on the surface of the circuit board where the LED chip is arranged and covers the LED chip.

[0024] In some embodiments, the periphery of the LED chip is filled with the first adhesive layer and the second adhesive layer of the packaging protective film, and in the thickness direction of the packaging protective film, the LED chip protrudes from the polyurethane elastomer in the second adhesive layer.

[0025] In another aspect of the present application, a display screen is provided, comprising the above-mentioned LED device.

[0026] Another aspect of the present application provides an electronic product including the above-mentioned display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a packaging protective film according to one embodiment of the present application;

[0028] Figure 2 This is a schematic structural diagram of an LED device according to one embodiment of the present application;

[0029] Description of reference numerals:

[0030] 10. LED device; 100. Encapsulation protective film; 110. Optical film layer; 120. Brightness enhancement film layer; 130. First adhesive layer; 140. Second adhesive layer; 142. Polyurethane elastomer; 150. Surface coating; 152. Anti-glare layer; 154. Hardening layer; 200. Circuit board; 300. LED chip. DETAILED DESCRIPTION

[0031] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0032] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0034] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0035] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0036] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] In this application, references to "combinations thereof", "any combination thereof", "any combination thereof" and the like include all suitable combinations of any two or more of the listed items.

[0038] In this application, the "suitable" mentioned in "suitable combination", "suitable method", "any suitable method", etc. shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0039] In this application, the terms "preferred", "better", "more preferred" and "suitable" are only used to describe implementation methods or examples with better effects. It should be understood that they do not constitute limitations on the scope of protection of this application.

[0040] In this application, the terms “further”, “further”, “particularly”, etc. are used for descriptive purposes to indicate differences in content, but should not be understood as limiting the scope of protection of this application.

[0041] In this application, the terms "optionally," "optional," and "optional" refer to options that are optional and may or may not be present, i.e., to the selection of either option from the two parallel options of "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or constraints, each "option" is independent.

[0042] In this application, the terms "first," "second," "third," "fourth," etc., in the "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor as implicitly indicating the importance or quantity of the indicated technical features. Furthermore, "first," "second," "third," "fourth," etc., are only used for non-exhaustive enumeration and description purposes, and should be understood not to constitute a closed-ended limitation on quantity.

[0043] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] In addition, the drawings are not drawn in a 1:1 scale, and the relative sizes of the elements are drawn in the drawings only as examples to facilitate understanding of the present application, but are not necessarily drawn in true proportion. The proportions in the drawings do not constitute a limitation to the present application.

[0046] See Figure 1 In one embodiment of the present application, a packaging protective film 100 is provided, including an optical film layer 110 , a brightness enhancement film layer 120 , a first adhesive layer 130 and a second adhesive layer 140 .

[0047] The optical film layer 110 contains a light-absorbing material. The light-absorbing material in the optical film layer 110 can control the transmittance of the packaging protective film 100, achieve a suitable shielding effect, and be used to encapsulate the LED device 10 to shield the solder pads on the circuit board 200, thereby improving the appearance of the LED device 10.

[0048] The brightness enhancement film layer 120 is disposed on the surface of the optical film layer 110. The brightness enhancement film layer 120 is used in the LED device 10 to enhance the light output brightness of the LED.

[0049] The first adhesive layer 130 is disposed on the surface of the brightness enhancement film 120 away from the optical film layer 110. The material of the first adhesive layer 130 is OCA optical adhesive. OCA optical adhesive is a specialized adhesive used for transparent optical components. It is colorless and transparent, has a light transmittance of ≥95%, has excellent bonding strength, can be cured at room or medium temperatures, and has minimal shrinkage upon curing. The first adhesive layer 130 made of OCA optical adhesive provides the encapsulation protective film 100 with excellent adhesion.

[0050] The second adhesive layer 140 is provided on the surface of the first adhesive layer 130 away from the brightness enhancement film layer 120. The material of the second adhesive layer 140 includes OCA optical glue and polyurethane elastomer 142, and the polyurethane elastomer 142 is evenly dispersed in the second adhesive layer 140. The polyurethane elastomer 142 (TPU) has excellent properties such as high strength, good toughness, wear resistance, and oil resistance. The TPU is evenly dispersed in the second adhesive layer 140 and can serve as the skeleton of the second adhesive layer 140, while the OCA optical glue serves as the main adhesive material. The second adhesive layer 140 has relatively suitable viscosity and mechanical properties and is easy to tear off after curing. Through the reasonable design of the first adhesive layer 130 and the second adhesive layer 140, the encapsulation protective film 100 can be torn off at room temperature while reducing the risk of residual glue.

[0051] Through the reasonable design of each functional layer, the above-mentioned packaging protective film 100 is used to encapsulate the LED device 10, which can ensure a high light output brightness of the LED while shielding the circuit board 200. The packaging protective film 100 can be torn off and debonded at room temperature, which facilitates the subsequent repair of the LED device 10.

[0052] In some embodiments, the brightness enhancement film layer 120 is a CRP (cholesteric reflective polarizer) brightness enhancement film. CRP brightness enhancement film is a cholesteric brightness enhancement film that improves light brightness through a light recycling mechanism. Specifically, the material of the brightness enhancement film layer 120 is reactive cholesteric liquid crystal.

[0053] Cholesteric liquid crystal has a naturally helical structure that is not destroyed by photopolymerization. When incident light enters, half of the incident light (circularly polarized light) enters along the helical structure, while the other half is reflected due to the reverse rotation. This is the so-called (circular) polarization selectivity. When cholesterol liquid crystal is used as a brightness enhancement film, when the light emitted by the backlight source passes through the cholesterol brightening film (such as left-handed cholesterol liquid crystal), right-handed polarized light will pass directly through, while left-handed circularly polarized light will be reflected. This reflected left-handed circularly polarized light will be re-reflected by the reflective backplane in the backlight module, and then become right-handed circularly polarized light and pass through the cholesterol brightening film, achieving the brightening effect.

[0054] In some embodiments, the material of the optical film layer 110 includes one of polyethylene terephthalate (PET), triacetyl cellulose (TAC), and cycloolefin polymer (COP), which have better optical properties.

[0055] In some embodiments, the light absorbing material includes at least one of melanin and carbon black.

[0056] In some embodiments, the polyurethane elastomer 142 is colorless and transparent or formulated in black. In some embodiments, the colorless and transparent polyurethane elastomer 142 ensures that the second adhesive layer 140 has good optical properties and high transmittance. In some embodiments, the polyurethane elastomer 142 is formulated in black and has light-absorbing properties, which can adjust the transmittance of the packaging protective film 100 and provide better shielding effect for the circuit board 200.

[0057] In some embodiments, the raw materials for preparing the polyurethane elastomer 142 may optionally include at least one of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), and polypropylene glycol (PPG).

[0058] In some embodiments, the encapsulation protection film 100 further includes a surface coating 150 . The surface coating 150 is disposed on a surface of the optical film layer 110 away from the brightness enhancement film layer 120 .

[0059] In some embodiments, the surface coating 150 includes an anti-glare layer 152 and a hardening layer 154. The hardening layer 154 and the anti-glare layer 152 are sequentially stacked on the surface of the optical film layer 110.

[0060] Specifically, the hardening layer 154 can be prepared by coating a hardening liquid. The hardening layer 154, referred to as the hc layer, can improve the mechanical properties of the packaging protective film 100. The anti-glare layer 152, referred to as the AG layer, can scatter light to achieve an anti-glare effect.

[0061] In some embodiments, the packaging protective film 100 further includes a release film layer disposed on the surface of the second adhesive layer 140 away from the first adhesive layer 130. The release film layer covers the second adhesive layer 140 to prevent the second adhesive layer from adhering to objects. During use, the packaging protective film 100 can be adhered to the surface of the device to be encapsulated by removing the release film layer.

[0062] Another embodiment of the present application further provides an LED device 10 , whose packaging structure is prepared using the above-mentioned packaging protective film 100 .

[0063] The LED device 10 uses the above-mentioned packaging protection film 100 to prepare a packaging structure, which can effectively shield the circuit board 200 of the LED device 10, ensure high light brightness, and facilitate subsequent repair.

[0064] See Figure 2 In some embodiments, the LED device 10 further includes a circuit board 200 and an LED chip 300. The LED chip 300 is disposed on a surface of the circuit board 200. The packaging structure is disposed on the surface of the circuit board 200 where the LED chip 300 is disposed and covers the LED chip 300.

[0065] In some embodiments, the periphery of the LED chip 300 is filled with the first adhesive layer 130 and the second adhesive layer 140 of the encapsulation protective film 100. In the thickness direction of the encapsulation protective film 100, the LED chip 300 protrudes from the polyurethane elastomer 142 in the second adhesive layer 140. During the encapsulation process, the first adhesive layer 130 and the second adhesive layer 140 of the encapsulation protective film 100 undergo some deformation and encapsulate the periphery of the LED chip 300. The protrusion of the LED chip 300 from the polyurethane elastomer 142 in the second adhesive layer 140 can largely ensure the front light extraction efficiency of the LED chip 300.

[0066] Another embodiment of the present application provides a display screen including the above-mentioned LED device 10.

[0067] Another embodiment of the present application further provides an electronic product including the above-mentioned display screen.

[0068] Specifically, electronic products include but are not limited to tablet computers, laptop computers, smart phones, etc.

[0069] In order to make the purpose, technical solutions and advantages of this application more concise and clear, this application is illustrated with the following specific examples, but this application is by no means limited to these examples. The embodiments described below are only preferred embodiments of this application and can be used to describe this application. They should not be understood as limiting the scope of this application. It should be pointed out that any modifications, equivalent replacements and improvements made within the spirit and principles of this application should be included in the scope of protection of this application.

[0070] In order to better illustrate the present application, the present application is further described below in conjunction with the embodiments. The following are specific embodiments.

[0071] Example 1

[0072] See Figure 1 This embodiment provides a packaging protective film 100, including a stacked anti-glare layer 152, a hardening layer 154, an optical film layer 110, a brightness enhancement film layer 120, a first adhesive layer 130, a second adhesive layer 140 and a release film layer.

[0073] The hardening layer 154 is formed by coating a hardening liquid on the surface of the optical film layer 110. The anti-glare layer 152 and the hardening layer 154 constitute the surface coating 150 of the encapsulation protection film 100.

[0074] The optical film layer 110 is made of PET and also includes melanin for adjusting the transmittance of the optical film layer 110 .

[0075] The brightness enhancement film layer 120 is a CRP brightness enhancement film.

[0076] The first adhesive layer 130 is made of OCA optical adhesive.

[0077] The second adhesive layer 140 is made of OCA optical adhesive and colorless and transparent polyurethane elastomer 142 . The polyurethane elastomer 142 is evenly dispersed in the OCA optical adhesive to form the second adhesive layer 140 .

[0078] The average transmittance of the packaging protection film 100 of this embodiment in the range of 400 nm to 800 nm is 30%.

[0079] Example 2

[0080] The packaging protective film 100 of this embodiment is substantially the same as that of embodiment 1, except that the content of melanin in the optical film layer 110 is different. The packaging protective film 100 of this embodiment has an average transmittance of 40% in the range of 400 nm to 800 nm.

[0081] Example 3

[0082] The packaging protective film 100 of this embodiment is substantially the same as that of embodiment 1, except that the content of melanin in the optical film layer 110 is different. The packaging protective film 100 of this embodiment has an average transmittance of 50% in the range of 400 nm to 800 nm.

[0083] Example 4

[0084] This embodiment provides a packaging protective film 100 , which differs from Embodiment 1 in that the second adhesive layer 140 is made of OCA optical glue and black polyurethane elastomer 142 , and the polyurethane elastomer 142 is uniformly dispersed in the OCA optical glue to form the second adhesive layer 140 .

[0085] The average transmittance of the packaging protection film 100 of this embodiment in the range of 400 nm to 800 nm is 20%.

[0086] Example 5

[0087] The packaging protective film 100 of this embodiment is substantially the same as that of embodiment 4, except that the content of melanin in the optical film layer 110 is different. The packaging protective film 100 of this embodiment has an average transmittance of 30% in the range of 400 nm to 800 nm.

[0088] Example 6

[0089] See Figure 2 This embodiment provides an LED device 10, which is encapsulated by the encapsulation protection film 100 of Example 1.

[0090] The LED device 10 includes a circuit board 200 , an LED chip 300 and a packaging structure made of a packaging protection film 100 .

[0091] Specifically, in this embodiment, the method for preparing the LED device 10 includes the following steps:

[0092] (1) Remove the release film layer of the packaging protective film 100, adhere the second adhesive layer 140 of the packaging protective film 100 to the surface of the circuit board 200 and the LED chip 300, and roll under a pressure of 0.65 MPa so that the first adhesive layer 130 and the second adhesive layer 140 are filled around the periphery of the LED chip 300. In the thickness direction of the packaging protective film 100, the LED chip 300 protrudes from the polyurethane elastomer 142.

[0093] (2) The LED device 10 with the package protection film 100 attached thereto is treated in a high-pressure degassing machine at 60° C. and 0.65 MPa for 30 minutes to remove bubbles.

[0094] (3) The device obtained in step (2) was subjected to UV curing, wherein the wavelength of the UV light source was 395 nm and the power was 3000 mW / cm2 , an LED device 10 is prepared.

[0095] The LED device 10 produced in this embodiment has a light output brightness of 45%, can effectively cover the solder pads on the circuit board 200, and has a good appearance. When the packaging structure is removed by side-tearing at 25°C, no adhesive residue is left on the surface of the circuit board 200 and the LED chip 300.

[0096] Example 7

[0097] The LED device 10 of this embodiment is substantially the same as that of the sixth embodiment, except that the LED device 10 is encapsulated by the encapsulation protection film 100 of the second embodiment.

[0098] The LED device 10 produced in this embodiment has a light output brightness of 55%, can effectively cover the solder pads on the circuit board 200, and has a good appearance. When the packaging structure is removed by side-tearing at 25°C, no adhesive residue is left on the surface of the circuit board 200 and the LED chip 300.

[0099] Example 8

[0100] The LED device 10 of this embodiment is substantially the same as that of the sixth embodiment, except that the LED device 10 is encapsulated by the encapsulation protection film 100 of the third embodiment.

[0101] The LED device 10 produced in this embodiment has a light output brightness of 65%, can effectively cover the solder pads on the circuit board 200, and has a good appearance. When the packaging structure is removed by side-tearing at 25°C, no adhesive residue is left on the surface of the circuit board 200 and the LED chip 300.

[0102] Example 9

[0103] The LED device 10 of this embodiment is substantially the same as that of the sixth embodiment, except that the LED device 10 is encapsulated by the encapsulation protection film 100 of the fourth embodiment.

[0104] The LED device 10 produced in this embodiment has a light output brightness of 50%, can effectively cover the solder pads on the circuit board 200, and has a good appearance. When the packaging structure is removed by side-tearing at 25°C, no adhesive residue is left on the surface of the circuit board 200 and the LED chip 300.

[0105] Example 10

[0106] The LED device 10 of this embodiment is substantially the same as that of the sixth embodiment, except that the LED device 10 is encapsulated by the encapsulation protection film 100 of the fifth embodiment.

[0107] The LED device 10 produced in this embodiment has a light output brightness of 60%, can effectively cover the solder pads on the circuit board 200, and has a good appearance. When the packaging structure is removed by side-tearing at 25°C, no adhesive residue is left on the surface of the circuit board 200 and the LED chip 300.

[0108] Comparative Example 1

[0109] This comparative example 1 provides a packaging protective film, comprising a laminated PET optical film layer and an OCA adhesive layer, wherein the PET optical film layer contains melanin.

[0110] The average transmittance of the packaging protective film of this comparative example in the range of 400 nm to 800 nm is 40%.

[0111] Comparative Example 2

[0112] The difference between this comparative example and Example 6 is that the LED device is encapsulated by the encapsulation protective film of Comparative Example 1.

[0113] The LED device of this comparative example has a light output brightness of 40%, can effectively cover the solder pads on the circuit board, and has a good appearance. The packaging structure cannot be torn off at 25°C.

[0114] The performance data of the encapsulation protection films and LED devices of Examples 1 to 10 and Comparative Examples 1 to 2 are recorded in Table 1.

[0115] Table 1

[0116] Encapsulation protective film Average transmittance (%) LED devices Luminance (%) Example 1 30 Example 6 45 Example 2 40 Example 7 55 Example 3 50 Example 8 65 Example 4 20 Example 9 50 Example 5 30 Example 10 60 Comparative Example 1 40 Comparative Example 2 40

[0117] As shown in Table 1, the average transmittance of the encapsulation protective films of Examples 1-5 within the 400nm-800nm ​​range is 20%-50%. This suitable transmittance allows shielding the solder pads on the circuit board, improving the appearance of the LED device. The corresponding LED devices produced in Examples 6-10 exhibited a brightness of 45%-65%, demonstrating both good appearance and high brightness. Furthermore, the encapsulation structure can be removed at 25°C without leaving any adhesive residue.

[0118] The polyurethane elastomer in the packaging protective film of Examples 4-5 is formulated to be black. Compared with the packaging protective film of Examples 1-3, the average transmittance is lower, which can better shield the circuit board pads. The light output brightness of the LED devices of Examples 9-10 prepared therefrom is 50% to 60%, which is higher than the LED devices of Examples 5-8 using packaging protective films with the same average transmittance. It can be seen that the black polyurethane elastomer can not only serve as the skeleton of the second adhesive layer to improve the risk of peeling off residual glue of the packaging protective film at room temperature, but also can serve as a light-absorbing material to adjust the average transmittance of the packaging protective film and improve the appearance of the LED device. The LED chip protrudes from the black polyurethane elastomer, which will not affect the light output from the front. While ensuring the light output brightness, the light output effect is better.

[0119] The average transmittance of the packaging protective film of Comparative Example 1 is 40%, which is the same as the average transmittance of the packaging protective film of Example 2. The light extraction efficiency of the LED device prepared in Comparative Example 2 is 40%, which is significantly lower than that of the LED device in Example 7. The packaging structure of the LED device in Comparative Example 2 cannot be torn off at 25°C.

[0120] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above only express several implementation methods of the present application, which are convenient for understanding the technical solutions of the present application in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all fall within the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the attached claims described in the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A packaging protective film, characterized in that: include: an optical film layer containing a light-absorbing material; A brightness enhancement film layer, the brightness enhancement film layer being disposed on the surface of the optical film layer; a first adhesive layer, the first adhesive layer being disposed on a surface of the brightness enhancement film layer away from the optical film layer; the first adhesive layer being made of OCA optical adhesive; and The second adhesive layer is arranged on the surface of the first adhesive layer away from the brightness enhancement film layer; the material of the second adhesive layer includes OCA optical glue and polyurethane elastomer, and the polyurethane elastomer is uniformly dispersed in the second adhesive layer.

2. The encapsulation protection film according to claim 1, characterized in that: The material of the brightness enhancement film layer is reactive cholesteric liquid crystal.

3. The encapsulation protection film according to claim 1, wherein: The material of the optical film layer includes one of polyethylene terephthalate, triacetyl cellulose and cycloolefin polymer.

4. The encapsulation protection film according to claim 1, wherein: The polyurethane elastomer is colorless and transparent or formulated in black.

5. The encapsulation protection film according to any one of claims 1 to 4, characterized in that: The encapsulation protection film satisfies at least one of the following conditions (1) to (3): (1) The encapsulation protective film further includes a surface coating; the surface coating is provided on the surface of the optical film layer away from the brightness enhancement film layer; (2) The encapsulation protective film further includes a release film layer, and the release film layer is provided on a surface of the second adhesive layer away from the first adhesive layer; (3) The light-absorbing material includes at least one of melanin and carbon black.

6. The encapsulation protection film according to claim 5, characterized in that: The encapsulation protective film satisfies the conditions of including the surface coating, the surface coating being arranged on the surface of the optical film layer away from the brightness enhancement film layer, the surface coating including an anti-glare layer and a hardening layer; the hardening layer and the anti-glare layer are sequentially stacked on the surface of the optical film layer.

7. An LED device, characterized in that: The packaging structure is prepared by using the packaging protective film described in any one of claims 1 to 6.

8. The LED device according to claim 7, characterized in that The LED device also includes a circuit board and an LED chip; The LED chip is arranged on the surface of the circuit board; The packaging structure is arranged on the surface of the circuit board where the LED chip is arranged and covers the LED chip.

9. The LED device according to claim 8, characterized in that The periphery of the LED chip is filled with the first adhesive layer and the second adhesive layer of the package protection film, and in the thickness direction of the package protection film, the LED chip protrudes from the polyurethane elastomer in the second adhesive layer.

10. A display screen, characterized in that: The LED device comprises the LED device according to any one of claims 7 to 9.

11. An electronic product, characterized in that: The invention comprises the display screen according to claim 10.

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