LED packaging film, application of LED packaging film and LED packaging structure

Abstract

The present invention provides an LED encapsulation film, an application of the LED encapsulation film, and an LED encapsulation structure. The raw materials for forming the LED encapsulation film include a base resin, the base resin includes a base resin modified by a tackifier, the LED encapsulation film is a single-layer film, the melting index of the LED encapsulation film for the structure close to one side of the LED optical unit is 5 to 45 g / 10 min, the bonding force between the LED encapsulation film and the LED optical unit is greater than 30 N / cm, and the light transmittance of the LED encapsulation film is greater than 80%. The melting index of the base resin of the LED encapsulation film for the structure close to one side of the LED optical unit is high, and when the LED encapsulation device is heated during rework, the LED encapsulation film has high fluidity based on the low melting index, which is conducive to the separation of the LED encapsulation film; the bonding force between the LED encapsulation film and the LED optical unit ensures the bonding stability of the LED encapsulation film.

Description

Technical Field

[0001] The present invention relates to the field of LED display, and in particular to an LED packaging film, an application of the LED packaging film and an LED packaging structure. Background Art

[0002] LED display devices are a kind of display screen made of LED unit boards. The structure of the LED unit board is shown in the figure below. There are LED optical units of different sizes, different spacings, and different numbers distributed on the circuit board. In some outdoor fields, there is often a layer of potting glue to enhance the waterproof performance. The LED unit boards can be seamlessly connected without splicing obstacles. Different combinations can be used according to the needs of use, and display screens of different sizes can be spliced. At the same time, the LED display screen can control the brightness and color of the lamp beads through the chip according to different lighting conditions, such as indoors and outdoors, facing the sun and back to the sun, etc., and has good adjustability. Therefore, LED display devices have developed rapidly in recent years, especially in the field of outdoor displays. However, the resolution of LED is not as good as LCD, and cannot meet some higher-end display requirements.

[0003] With the continuous advancement of microelectronics technology, the LED optical units and spacing of LED display screens are getting smaller and smaller, and the display effect is constantly improving, which can break the monopoly of LCD in the field of high-end displays. However, the LED optical units of LED display devices will have problems such as falling off and dead light, which will affect the display effect and increase after-sales costs. In the outdoor field, due to environmental factors, the failure rate of LED optical units is higher. At present, one of the methods adopted in the industry is to cover the display screen with a protective cover, but the protective cover will affect the display effect. Therefore, whether it is because the LED optical unit falls off during the production process or fails during use, the current LED packaging method cannot split the packaging structure to achieve the replacement of a single LED optical unit, which makes it difficult to repair LED display devices. Summary of the invention

[0004] The main purpose of the present invention is to provide an LED packaging film, an application of the LED packaging film and an LED packaging structure to solve the problem of difficulty in repairing LED packaging devices in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an LED encapsulation film, the raw materials for forming the LED encapsulation film include a base resin, the base resin includes a base resin modified by a tackifier, the above-mentioned LED encapsulation film is a single-layer film, the melt index of the LED encapsulation film for the structure on one side close to the LED optical unit is 5 to 45 g / 10 min, the bonding force between the LED encapsulation film and the LED optical unit is greater than 30 N / cm, and the light transmittance of the LED encapsulation film is greater than 80%.

[0006] Furthermore, the LED encapsulation adhesive film is a thermoplastic resin film, and the matrix resin is a first matrix resin modified by a tackifier, or includes a second matrix resin and a first matrix resin modified by a tackifier.

[0007] Furthermore, the weight ratio of the first matrix resin modified by the tackifier to the second matrix resin is 20:80 to 100:0.

[0008] Furthermore, the first matrix resin and the second matrix resin are independently selected from one or more of ethylene vinyl acetate copolymer, ethylene propylene copolymer, ethylene butene copolymer, ethylene pentene copolymer, ethylene hexene copolymer, ethylene octene copolymer and polyvinyl butyral.

[0009] Furthermore, the above-mentioned adhesion promoter is a silane coupling agent.

[0010] Furthermore, the thickness of the LED packaging film is 50-500 μm.

[0011] Furthermore, the thickness of the LED packaging film is 100-300 μm.

[0012] Furthermore, the light transmittance of the LED packaging film is greater than 85%.

[0013] Furthermore, the surface of the LED encapsulation film at a side away from the LED optical unit has embossing, and the depth of the embossing is preferably 10 μm to 100 μm.

[0014] According to another aspect of the present invention, there is provided a use of any one of the above-mentioned LED encapsulation adhesive films in LED encapsulation.

[0015] According to another aspect of the present invention, there is provided an LED packaging structure, which includes: a substrate, a plurality of LED optical units, which are spaced apart on a surface of the substrate; and a packaging portion, which covers the LED optical units, wherein the packaging portion includes a packaging film, which is any one of the above-mentioned LED packaging films.

[0016] Furthermore, the packaging part further comprises a potting glue, which is arranged on the substrate between the LED optical units, and a packaging glue film covers the potting glue and the LED optical units.

[0017] By applying the technical solution of the present invention, the melting index of the base resin of the LED encapsulation film of the present application used for the structure on one side close to the LED optical unit is 5 to 45 g / 10 min. Therefore, when the LED encapsulation device is heated during rework, the LED encapsulation film has higher fluidity due to the low melting index, which is beneficial to the separation of the LED encapsulation film. In addition, since the bonding force between the LED encapsulation film and the LED optical unit is greater than 30 N / cm, the bonding stability of the LED encapsulation film is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A cross-sectional schematic diagram of an LED packaging structure provided according to an embodiment of the present invention is shown; and

[0020] Figure 2 A cross-sectional schematic diagram of an LED packaging structure provided according to another embodiment of the present invention is shown.

[0021] The above drawings include the following reference numerals:

[0022] 10. Substrate; 20. LED optical unit; 31. Potting glue; 32. Encapsulation glue film layer. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] As analyzed in the background technology of the present application, it is difficult to repair LED packaging devices in the prior art. In order to solve this problem, the present application provides an LED packaging film and an LED packaging structure.

[0025] In a typical embodiment of the present application, an LED encapsulation film is provided. The raw materials for forming the LED encapsulation film include a base resin, and the base resin includes a base resin modified by a tackifier, such as Figure 1 As shown, the LED encapsulation film is a single-layer film, and the melting index of the LED encapsulation film for the structure close to the LED optical unit 20 is 5 to 45 g / 10 min. The bonding force between the LED encapsulation film and the LED optical unit 20 is greater than 30 N / cm, and the light transmittance of the LED encapsulation film is greater than 80%.

[0026] The LED encapsulation film of the present application has a melting index of 5 to 45 g / 10 min for the base resin of the structure on one side close to the LED optical unit 20. Therefore, when the LED encapsulation device is heated during rework, the LED encapsulation film has higher fluidity due to the low melting index, which is beneficial to the separation of the LED encapsulation film. In addition, since the bonding force between the LED encapsulation film and the LED optical unit 20 is greater than 30 N / cm, the bonding stability of the LED encapsulation film is guaranteed.

[0027] The base resin of the LED encapsulation film used in the present application can be selected from currently commonly used resins that meet the above requirements, and LED encapsulation films with different structures or properties can be formed by processing different resins or films.

[0028] When the LED encapsulation film is preferably a thermoplastic resin film, the matrix resin is a first matrix resin modified by a tackifier, or includes a second matrix resin and a first matrix resin modified by a tackifier.

[0029] In order to improve the bonding force between the LED encapsulation film and the LED optical unit 20 as much as possible, the weight ratio of the first matrix resin modified by the tackifier to the second matrix resin is preferably 20:80-100:0.

[0030] The first matrix resin and the second matrix resin used for the above-mentioned single-layer film can be selected from the resins commonly used in the packaging film in the prior art. In order to improve the light transmittance as much as possible and meet the requirements of weather resistance, light transmittance, etc. during LED packaging, it is preferred that the above-mentioned first matrix resin and the second matrix resin are independently selected from one or more of ethylene vinyl acetate copolymer, ethylene propylene copolymer, ethylene butene copolymer, ethylene pentene copolymer, ethylene hexene copolymer, ethylene octene copolymer, and polyvinyl butyral. After the LED packaging is completed, the above-mentioned thermoplastic resin film can be heated to form fluidity for easy repair when it needs to be repaired; in addition, since it is a thermoplastic film, it maintains fluidity during the LED packaging process, and its filling property is better when facing the LED optical unit 20 with more gaps. Moreover, the hardness of each of the above-mentioned polymers is relatively small, so it is easier to fit with the LED optical unit 20. If necessary, a hard protective layer is set on the outside of the above-mentioned LED packaging film to compensate for the hardness of the above-mentioned single-layer film.

[0031] In some embodiments, the thickness of the LED packaging film is preferably 50-500 μm, more preferably 100-300 μm. The LED packaging film in the above thickness range can not only provide a firm packaging for the LED optical unit 20, but also does not cause the volume of the LED packaging structure to be too large.

[0032] In order to further improve the light transmittance of the LED packaging film and thus improve the light efficiency of the LED packaging film, it is preferred that the light transmittance of the LED packaging film is greater than 85%. The light transmittance can be ensured by the selection of the matrix resin. Those skilled in the art can select the corresponding resin based on knowing the light transmittance of the matrix resin and satisfying one or more of the above requirements, and this application will not list them one by one.

[0033] In some embodiments, the surface of the LED encapsulation film away from the LED optical unit 20 has embossing, and the embossing depth is 10 μm to 100 μm. By providing embossing, the light diffusion characteristics of the display screen can be improved, and the best display effect can be presented at all viewing angles.

[0034] In another typical embodiment of the present application, there is provided an application of any LED packaging adhesive film of the present application in LED packaging, which can achieve good repair of LED packaging devices.

[0035] In another typical embodiment of the present application, an LED packaging structure is provided, such as Figure 1 As shown in or 2, the LED packaging structure includes a substrate 10, a plurality of LED optical units 20 and a packaging part, wherein the LED optical units 20 are arranged at intervals on a surface of the substrate 10; the packaging part covers the LED optical units 20, and the packaging part includes a packaging film 32, which is any one of the above-mentioned LED packaging films.

[0036] The LED encapsulation film of the present application has a melting index of 5 to 45 g / 10 min for the base resin of the structure on one side close to the LED optical unit 20. Therefore, when the LED encapsulation device is heated during rework, the LED encapsulation film has higher fluidity due to the low melting index, which is beneficial to the separation of the LED encapsulation film. In addition, since the bonding force between the LED encapsulation film and the LED optical unit 20 is greater than 30 N / cm, the bonding stability of the LED encapsulation film is guaranteed.

[0037] In some embodiments of the present application, Figure 2 As shown, the packaging part further includes a potting glue 31, which is disposed on the substrate 10 between the LED optical units 20, and a packaging glue film 32 covers the potting glue 31 and the LED optical units 20. The potting glue 31 is used to pot the gaps of the LED optical units 20.

[0038] The beneficial effects of the present application will be further illustrated below in combination with embodiments and comparative examples.

[0039] Example 1

[0040] The LED encapsulation adhesive film of Example 1 is a single-layer film with a thickness of 250 μm, and its raw material is a silane-grafted ethylene-octene copolymer (Dow Chemical) with a melt index of 12 g / 10 min.

[0041] Example 2

[0042] The LED encapsulation film of Example 2 is a single-layer film with a thickness of 350 μm, and its raw materials are 70 wt % of silane-grafted ethylene-octene copolymer with a melt index of 12 g / 10 min (Dow Chemical) and 30 wt % of ethylene-vinyl acetate copolymer with a melt index of 45 g / 10 min (Taiwan Polymer Co., Ltd., Taiwan, China).

[0043] Example 3

[0044] Example 3 The LED encapsulation film is a single-layer film with a thickness of 450 μm, and its raw materials are 20 wt % silane-grafted ethylene-vinyl acetate copolymer (DuPont) with a melt index of 40 g / 10 min and 80 wt % ethylene-octene copolymer (Dow Chemical) with a melt index of 5 g / 10 min.

[0045] Example 4

[0046] The LED encapsulation film of Example 4 is a single-layer film with a thickness of 500 μm, and its raw materials are 50 wt % of silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 15 g / 10 min and 50 wt % of ethylene-butene copolymer with a melt index of 25 g / 10 min.

[0047] Example 5

[0048] The LED encapsulation film of Example 5 is a single-layer film with a thickness of 50 μm, and its raw materials are 40 wt % of silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 10 g / 10 min and 60 wt % of ethylene-butene copolymer with a melt index of 15 g / 10 min.

[0049] Example 6

[0050] The LED encapsulation film of Example 6 is a single-layer film with a thickness of 300 μm, and its raw materials are 90 wt % of silane-grafted ethylene-octene copolymer (Dow Chemical) with a melt index of 12 g / 10 min and 10 wt % of ethylene-propylene copolymer (Dow Chemical) with a melt index of 10 g / min.

[0051] Example 7

[0052] The LED encapsulation film of Example 7 is a single-layer film with a thickness of 100 μm, and its raw materials are 80 wt % of silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 15 g / 10 min and 20 wt % of ethylene-pentene copolymer (Dow Chemical) with a melt index of 10 g / 10 min.

[0053] Example 8

[0054] The LED encapsulation film of Example 8 is a single-layer film with a thickness of 450 μm, and its raw materials are 10 wt % of silane-grafted ethylene-vinyl acetate copolymer (DuPont) with a melt index of 40 g / 10 min and 90 wt % of ethylene-octene copolymer (Dow Chemical) with a melt index of 5 g / 10 min.

[0055] Example 9

[0056] The LED encapsulation film of Example 9 is a single-layer film with a thickness of 500 μm. Its raw materials are 50 wt% silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 15 g / 10 min and 50 wt% ethylene-butene copolymer with a melt index of 25 g / 10 min, and there is a 100 μm deep embossing away from the optical unit surface.

[0057] Example 10

[0058] The LED encapsulation film of Example 10 is a single-layer film with a thickness of 500 μm. Its raw materials are 50 wt% silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 15 g / 10 min and 50 wt% ethylene-butene copolymer with a melt index of 25 g / 10 min, and there is an embossing with a depth of 50 μm away from the optical unit surface.

[0059] Embodiment 11

[0060] The LED encapsulation film of Example 11 is a single-layer film with a thickness of 500 μm. Its raw materials are 50 wt% silane-grafted ethylene-butene copolymer (Dow Chemical) with a melt index of 15 g / 10 min and 50 wt% ethylene-butene copolymer with a melt index of 25 g / 10 min, and there is an embossing with a depth of 10 μm away from the optical unit surface.

[0061] Comparative Example 1

[0062] The LED encapsulation film of Comparative Example 1 is a single-layer film with a thickness of 350 μm and 100 wt % of ethylene-vinyl acetate copolymer (Taiwan Polymer Co., Ltd., China) with a melt index of 45 g / 10 min.

[0063] The components in the above embodiments and comparative examples are mixed in proportion and added into an extruder, and precisely extruded by a screw and cast into a film through a T-die. For the convenience of comparison in the above embodiments and comparative examples, the thickness of the cast film is uniformly 0.5 mm.

[0064] The encapsulation film obtained by the above embodiment is applied to the encapsulation of solar cell modules and evaluated by the following test method. The evaluation results are listed in Table 1:

[0065] 1. Transmittance of encapsulation film

[0066] The test method refers to the standard GB / T 29848 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation".

[0067] 2.25℃ Adhesion to LED optical unit

[0068] The PCB board of the LED optical unit is 15×15cm, and the distance between the lamp beads is 0.5mm.

[0069] After stacking and laminating in the order of LED optical unit / encapsulation film / flexible backsheet, the test was performed after standing for 1 hour at 25°C. The lamination conditions were: temperature 150°C, vacuum-6min, 30KPa-0.5min, 60KPa-0.5min, 100KPa-10min. The specific method refers to the standard GB / T 29848 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation".

[0070] 3.110℃ Adhesion to LED optical unit

[0071] The PCB board of the LED optical unit is 15×15cm, and the distance between the lamp beads is 0.5mm.

[0072] After stacking and laminating in the order of LED optical unit / packaging film / flexible backplane, let it stand for 1 hour in an environment of 110℃ and then test. Lamination conditions: temperature 150℃, vacuum-6min, 30KPa-0.5min, 60KPa-0.5min, 100KPa-10min. The specific method refers to the standard GB / T 29848 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation".

[0073] 4. Shore hardness of the film

[0074] Shore hardness test refers to GB2411-1980 (1989).

[0075] The test results are recorded in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0080] The LED encapsulation film of the present application has a melting index of 5 to 45 g / 10 min for the base resin of the structure close to one side of the LED optical unit. Therefore, when the LED encapsulation device is heated during rework, the LED encapsulation film has higher fluidity due to the low melting index, which is beneficial to the separation of the LED encapsulation film. In addition, since the bonding force between the LED encapsulation film and the LED optical unit is greater than 30 N / cm, the bonding stability of the LED encapsulation film is guaranteed.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An application of an LED encapsulation film in LED encapsulation, wherein the raw material for forming the LED encapsulation film comprises a base resin, wherein the base resin comprises a base resin modified by a tackifier, wherein: The LED encapsulation film is a single-layer film, the melt index of the LED encapsulation film for the structure close to the LED optical unit is 5-45g / 10min, the bonding force between the LED encapsulation film and the LED optical unit is greater than 30N / cm, and the light transmittance of the LED encapsulation film is greater than 80%; the thickness of the LED encapsulation film is 50-500μm, and the LED encapsulation film is a thermoplastic resin film; When the LED packaging device is heated during rework, the LED packaging film base and the LED optical unit are separated; The base resin includes a second base resin and a first base resin modified by a tackifier, and the tackifier is a silane coupling agent; The weight ratio of the first matrix resin modified by the tackifier to the second matrix resin is 20:80-100:0; The first matrix resin and the second matrix resin are independently selected from one or more of ethylene vinyl acetate copolymer, ethylene propylene copolymer, ethylene butene copolymer, ethylene pentene copolymer, ethylene hexene copolymer and ethylene octene copolymer.

2. Application of the LED packaging film according to claim 1 in LED packaging, characterized in that: The thickness of the LED packaging film is 100-300 μm.

3. Application of the LED packaging film according to claim 1 in LED packaging, characterized in that: The light transmittance of the LED packaging film is greater than 85%.

4. The use of the LED encapsulation film according to any one of claims 1 to 3 in LED encapsulation, characterized in that: The surface of the LED packaging film away from the LED optical unit has embossing.

5. Application of the LED encapsulation film according to claim 4 in LED encapsulation, characterized in that: The embossing depth is 10 μm to 100 μm.

6. An LED packaging structure, comprising: base plate (10), A plurality of LED optical units (20) are arranged at intervals on a surface of the substrate (10); A packaging part covering the LED optical unit (20), the packaging part comprising a packaging adhesive film (32), It is characterized in that the packaging adhesive film (32) is the LED packaging adhesive film used in LED packaging as claimed in any one of claims 1 to 5.

7. The LED packaging structure according to claim 6, characterized in that: The packaging part further comprises a potting glue (31), wherein the potting glue (31) is arranged on the substrate (10) between the LED optical units (20), and the packaging glue film (32) covers the potting glue (31) and the LED optical units (20).

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