Light-emitting device and LED packaging structure

Abstract

The utility model provides a light-emitting device and an LED packaging structure. The utility model discloses an LED packaging structure, and the structure comprises a substrate which is provided with a first surface and a second surface, and the first surface and the second surface are arranged in a back-to-back manner. The light-emitting unit is arranged on the first surface of the substrate; the plurality of heat dissipation plates are arranged on the second surface of the substrate and are in thermal contact with the substrate; and the adjacent heat dissipation plates are arranged at intervals. By arranging the plurality of heat dissipation plates on the second surface of the substrate, the size of the heat dissipation plates is reduced, and the plurality of heat dissipation plates are dispersedly arranged, so that the heat stress is conveniently released, and the warping phenomenon is reduced.

Description

Technical Field

[0001] This application relates to the field of LED packaging, specifically to a light-emitting device and an LED packaging structure. Background Technology

[0002] Traditionally, in LED packaging structures, a heat sink is placed on the back of the substrate to improve heat dissipation. However, during use, the heat sink is prone to warping. Summary of the Invention

[0003] This application provides a light-emitting device and an LED packaging structure that reduce warping phenomena through multiple embodiments.

[0004] This application provides an LED packaging structure, the LED packaging structure comprising:

[0005] The substrate has a first surface and a second surface disposed opposite to each other;

[0006] A light-emitting unit is disposed on the first surface of the substrate; and

[0007] Multiple heat sinks are disposed on the second surface of the substrate and are in thermal contact with the substrate; adjacent heat sinks are spaced apart.

[0008] In some embodiments, the heat sink is in the form of a polygon that can be tiled closely.

[0009] In some embodiments, the surface of the heat sink away from the substrate is a heat dissipation surface, and at least a portion of the heat dissipation surface of the heat sink is uneven.

[0010] In some embodiments, the heat dissipation surface of the heat sink is provided with a plurality of grooves;

[0011] Alternatively, the heat dissipation surface of the heat sink may be wavy.

[0012] In some embodiments, at least a portion of the heat sink is in the shape of a regular hexagon, a regular triangle, a right triangle, a square, or a rectangle.

[0013] In some embodiments, the plurality of heat sinks are arranged in an array.

[0014] In some embodiments, a first pad is provided on a first surface of the substrate, and a second pad is provided on a second surface that corresponds one-to-one with the first pad; a conductive hole is provided through the substrate; the LED packaging structure further includes a lead wire passing through the conductive hole, and the two ends of the lead wire are electrically connected to the first pad and the corresponding second pad, respectively.

[0015] In some embodiments, the first surface of the substrate includes a light-emitting region and a first pad region surrounding the light-emitting region; the second surface of the substrate includes a heat-dissipating region and a second pad region surrounding the heat-dissipating region.

[0016] The light-emitting unit is disposed in the light-emitting area; the first pad is disposed in the first pad area; the plurality of heat sinks are disposed in the heat dissipation area; and the second pad is disposed in the second pad area.

[0017] In some embodiments, the first pad and the corresponding second pad are arranged in a direction perpendicular to the substrate.

[0018] In some embodiments, the substrate is a ceramic substrate.

[0019] In some embodiments, the light-emitting unit includes a light-emitting chip and a fluorescent layer covering the light-emitting chip; the fluorescent layer is used to change the color of the light emitted by the light-emitting chip.

[0020] Alternatively, the LED packaging structure may include multiple light-emitting units, some of which may include a light-emitting chip and a phosphor layer covering the light-emitting chip; the phosphor layer is used to change the color of the light emitted by the light-emitting chip.

[0021] In some embodiments, the LED encapsulation structure further includes a white glue encapsulation structure disposed around the sidewall of the light-emitting unit.

[0022] This application also provides a light-emitting device, including the LED packaging structure provided in this application.

[0023] The various embodiments provided in this application reduce the size of the heat sink by providing multiple heat sinks on the second surface of the substrate, and the multiple heat sinks are distributed to facilitate the release of thermal stress and reduce warping. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an LED packaging structure provided in one embodiment of this application.

[0025] Figure 2 for Figure 1 A cross-sectional view of the LED package structure along the MM direction.

[0026] Figure 3 for Figure 1 A schematic diagram of the LED packaging structure from another perspective.

[0027] Figure 4 This is a schematic diagram of an LED packaging structure provided in another embodiment of this application.

[0028] Explanation of reference numerals in the attached figures

[0029] 100 / 200, LED packaging structure; 110, substrate; 111, first surface; 1111, light-emitting area; 1112, first pad area; 112, second surface; 1121, heat dissipation area; 1122, second pad area; 113, first pad; 114, second pad; 115, conductive hole; 116, lead wire; 120, light-emitting unit; 130, heat sink; 131, heat dissipation surface; 132, groove; 140, white glue encapsulation structure. Detailed Implementation

[0030] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0031] In this application, the accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features.

[0032] Unless otherwise stated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0033] In the description of this application, it should be understood that 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 indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified. In the description of this application, "several" means one or more, unless otherwise explicitly specified.

[0034] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0035] In the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In the description of this application, unless otherwise expressly defined, the terms "above," "over," "on top of," "below," "below," "under," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "below," and "over" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0037] Researchers have discovered that the warping of heat sinks in traditional LED packaging structures occurs because thermal stress is generated when the heat sink temperature rises. However, due to the large size of the heat sink, this thermal stress is difficult to release.

[0038] Based on this, researchers proposed an LED packaging structure that replaces the traditional heat sink with multiple smaller heat sinks spaced apart from each other. The reduced size of the heat sinks decreases the thermal stress on each individual sink; furthermore, the absence of contact between heat sinks and adjacent sinks facilitates the release of thermal stress and reduces warping.

[0039] See Figures 1 to 3An embodiment of this application provides an LED packaging structure 100, including a substrate 110, a light-emitting unit 120, and a heat sink 130. The substrate 110 has a first surface 111 and a second surface 112 disposed opposite to each other; the light-emitting unit 120 is disposed on the first surface 111 of the substrate 110; a plurality of heat sinks 130 are disposed on the second surface 112 of the substrate 110 and are in thermal contact with the substrate 110; adjacent heat sinks 130 are spaced apart.

[0040] The LED packaging structure 100 described above reduces the size of the heat sink 130 by providing multiple heat sinks 130 on the second surface 112 of the substrate 110, and the multiple heat sinks 130 are distributed to facilitate the release of thermal stress and reduce warping.

[0041] It should be noted that, in this application, the size of the heat sink 130 refers to the area of ​​the heat sink 130 along the direction parallel to the substrate 110. Multiple heat sinks 130 are provided to reduce the size of each heat sink 130. Adjacent heat sinks 130 are spaced apart, thus distributing the multiple heat sinks 130.

[0042] The reduced size of the heat sink 130 decreases the thermal stress generated by each heat sink. The spaced arrangement of the heat sink 130 with adjacent heat sinks allows the edges of the heat sink 130 to be free, facilitating the release of thermal stress. Therefore, the thermal stress of the heat sink 130 is reduced and easily released, thereby minimizing warping.

[0043] In this embodiment, the heat sink 130 is in the shape of a polygon that can be densely laid out. This facilitates the arrangement of the heat sink 130, resulting in a larger total area of ​​all the heat sinks 130 and improving heat dissipation efficiency.

[0044] It should be noted that the term "potentially tiling polygon" refers to the shape of the heat sink 130, which allows for splicing and seamless laying of the heat sinks without gaps or overlaps. While it is understood that the heat sink 130 is a tiling polygon, meaning its shape allows for close tiling, in this application, there are gaps between adjacent heat sinks 130, thus the heat sinks 130 are distributed.

[0045] In this application, the heat sink 130 is a polygonal shape that can be densely laid out, and multiple heat sinks 130 can be reasonably arranged to increase the density of heat sinks 130, increase the total area of ​​all heat sinks 130, and improve heat dissipation efficiency while ensuring that adjacent heat sinks 130 are spaced apart.

[0046] In this embodiment, the heat sink 130 is in the shape of a regular hexagon. It is understood that in other embodiments, the heat sink 130 is not limited to a regular hexagon, but may also be in the shape of an equilateral triangle, a right triangle, a square, a rectangle, etc.

[0047] Optionally, the multiple heat sinks 130 have the same shape and are of equal size. It is understood that in some embodiments, the multiple heat sinks 130 may have different shapes and sizes. Specifically, in this embodiment, the second surface 112 has a heat dissipation area 1121 for mounting the heat sinks 130; the heat sinks 130 located in the middle of the heat dissipation area 1121 are all hexagonal; the shape of the heat sinks 130 located at the edges of the heat dissipation area 1121 is adaptively adjusted according to the shape of the edges of the heat dissipation area 1121, so that all the heat sinks 130 can be densely packed, increasing the total area of ​​all the heat sinks 130.

[0048] In addition, the heat sink 130 is hexagonal in shape, and the size of the inner angle of the heat sink 130 is 120°, which is a large angle. This reduces the phenomenon of thermal stress concentration at the corners of the heat sink 130 and improves the service life of the heat sink 130.

[0049] Furthermore, the heat sink 130 is hexagonal in shape, with a relatively large interior angle of 120°. This design reduces stress concentration at the corners of the heat sink 130 during fabrication, thereby improving the yield rate.

[0050] Furthermore, the heat sink 130 is hexagonal in shape, with an interior angle of 120°. The angle is relatively large, resulting in greater strength at the corners of the heat sink 130. It can withstand greater stress and is less prone to strain, thus reducing the risk of warping.

[0051] In this embodiment, each heat sink 130 has the same shape and size. It is understood that in other embodiments, the shapes and sizes of the different heat sinks 130 may also be different.

[0052] In this embodiment, multiple heat sinks 130 are arranged in a spaced-apart, closely spaced manner. That is, the relatively close arrangement is appropriately adjusted so that adjacent heat sinks 130 are spaced apart. This not only achieves the dispersed arrangement of multiple heat sinks 130, but also increases the density of heat sinks 130 and improves the heat dissipation effect.

[0053] Optionally, the spacing between adjacent heat sinks 130 falls within the range of 80μm to 200μm, which, even with the release of thermal stress in the heat sinks 130, also results in a higher density of the heat sinks 130. In other words, it can reduce the warping of the heat sinks 130 and also has a better heat dissipation effect.

[0054] In addition, during the fabrication of some heat sinks 130, a large plate-shaped structure is first generated, and then cut into several heat sinks 130 by means of etching or other methods. The spacing between adjacent heat sinks 130 is not less than 80μm, which also facilitates the cutting process and reduces the cutting difficulty.

[0055] In this embodiment, the first surface 111 of the substrate 110 is provided with a first pad 113, and the second surface 112 is provided with a second pad 114 corresponding to the first pad 113; a conductive hole 115 is provided through the substrate 110; the LED packaging structure 100 further includes a lead wire 116 passing through the conductive hole 115, and the two ends of the lead wire 116 are electrically connected to the first pad 113 and the corresponding second pad 114, respectively.

[0056] The lead 116 for connecting the first pad 113 and the corresponding second pad 114 passes through the conductive hole 115, avoiding occupying space outside the sidewall of the substrate 110 and facilitating the miniaturization design of the LED package structure 100. In addition, the length of the lead 116 can be reduced to improve the response speed of the light-emitting unit 120.

[0057] In addition, the lead 116 does not need to go around the side of the substrate 110, which facilitates packaging, reduces the risk of moisture corrosion to the lead 116, and improves the service life of the lead 116.

[0058] In this embodiment, the first surface 111 of the substrate 110 includes a light-emitting region 1111 and a first pad region 1112 surrounding the light-emitting region 1111; the second surface 112 of the substrate 110 includes a heat-dissipating region 1121 and a second pad region 1122 surrounding the heat-dissipating region 1121; the light-emitting unit 120 is disposed in the light-emitting region 1111; the first pad 113 is disposed in the first pad region 1112; the plurality of heat sinks 130 are disposed in the heat-dissipating region 1121, and the second pad 114 is disposed in the second pad region 1122. The light-emitting unit 120 and the first pad 113 are partitioned to reduce interference between the light-emitting unit 120 and the first pad 113 due to manufacturing precision issues, thereby avoiding short circuits. The heat sinks 130 and the second pad 114 are partitioned to avoid interference between the heat sinks 130 and the second pad 114 due to manufacturing precision issues, thereby avoiding short circuits.

[0059] It should be noted that, Figure 3 In the middle, the light-emitting area 1111 and the first pad area 1112 are distinguished by red dashed lines. Figure 1 In the diagram, the heat dissipation area 1121 and the second pad area 1122 are distinguished by red dashed lines. It's understandable that the red dashed lines are there to facilitate differentiation between the different areas and do not actually exist.

[0060] In this application, multiple first pads 113 are distributed around the light-emitting area 1111, which facilitates wiring connection with the light-emitting unit 120 and simplifies the complexity of wiring.

[0061] In addition, the partitioning of the heat sink 130 and the second pad 114 increases the density of the heat sink 130 and the second pad 114, reduces the area of ​​the soldering area, and allows the heat dissipation area 1121 to be larger, thereby improving the heat dissipation effect.

[0062] The light-emitting unit 120 is located in the middle area of ​​the first surface 111, and the heat dissipation area 1121 is also located in the middle area of ​​the second surface 112, so that the light-emitting unit 120 is close to the heat dissipation plate 130, which facilitates heat dissipation.

[0063] Furthermore, the light-emitting units 120 are located in the middle region of the first surface 111. The concentrated arrangement of the light-emitting units 120 facilitates improved light emission. On the one hand, it reduces the obstruction of light emission by other structures; on the other hand, when there are multiple light-emitting units 120, the directions of the light emitted by different light-emitting units 120 can be made closer, which facilitates the superposition of light from different light-emitting units 120.

[0064] More specifically, in this embodiment, the first pad 113 and the corresponding second pad 114 are arranged in a direction perpendicular to the substrate 110 and are respectively disposed on the first surface 111 and the second surface 112 of the substrate 110. The position of the conductive hole 115 corresponds to the position of the first pad 113. The lead 116 does not need to extend on the first surface 111 and the second surface 112 to achieve electrical connection with the corresponding first pad 113 and the second pad 114, further reducing the length of the lead 116.

[0065] In this embodiment, the substrate 110 is a ceramic substrate 110. The ceramic substrate 110 has good thermal conductivity, which facilitates the rapid dissipation of heat generated by the light-emitting unit 120, thereby preventing the light-emitting unit 120 from operating at high temperatures and improving its service life.

[0066] In this embodiment, the LED packaging structure 100 includes multiple light-emitting units 120. It is understood that in some other embodiments, the number of light-emitting units 120 may also be one, and the specific number can be set as needed, which is not limited here.

[0067] Optionally, the light-emitting unit 120 includes a light-emitting chip and a phosphor layer covering the light-emitting chip; the phosphor layer is used to change the color of the light emitted by the light-emitting chip to obtain the desired color of light. Further optionally, the LED package structure 100 includes multiple light-emitting units 120, and the colors of the light emitted by the light-emitting chips in different light-emitting units 120 can be the same or different; the colors of the phosphor layers in different light-emitting units 120 can be the same or different, so that the colors of the light emitted by the light-emitting units 120 are the same or different as needed, without limitation here.

[0068] It is understood that in some other embodiments, the LED package structure 100 includes a plurality of light-emitting units 120, some of which include a light-emitting chip and a phosphor layer covering the light-emitting chip; some of which include only a light-emitting chip.

[0069] It is understood that in some other embodiments, the LED package structure 100 may also include only one light-emitting unit 120, which includes a light-emitting chip and a phosphor layer covering the light-emitting chip.

[0070] Optionally, the LED packaging structure 120 further includes a white glue packaging structure 140 surrounding the sidewall of the light-emitting unit 120. The white glue packaging structure 140 improves the packaging stability of the light-emitting unit 120; it also reflects and blocks light, increasing the light emission efficiency and intensity of each light-emitting unit; furthermore, when there are multiple light-emitting units 120 and the emitted light colors are not identical, it can prevent different colors of light from mixing in an unintended manner, improving color accuracy.

[0071] Further optionally, in this embodiment, the areas of the light-emitting region 1111 without the light-emitting unit 120 are all covered by the white glue encapsulation structure 140, which facilitates the process implementation. Of course, in some other embodiments, the areas of the first surface 111 without the light-emitting unit 120 are all covered by the white glue encapsulation structure 140, which further facilitates the process implementation and can also simultaneously encapsulate the first pad 113.

[0072] Of course, in other embodiments, the encapsulation structure surrounding the sidewall of the light-emitting unit 120 is not limited to a white glue encapsulation structure, but can also be a black glue encapsulation structure, or a metal electroplating material, etc.

[0073] See Figure 4Another embodiment of this application provides an LED packaging structure 200, which differs from the LED packaging structure 100 in that the surface of the heat sink 130 facing away from the substrate 110 is a heat dissipation surface 131. The heat dissipation surface 131 of the heat sink 130 is not flat, which increases the heat dissipation area of ​​the heat sink 130 and improves the heat dissipation efficiency of the heat sink 130.

[0074] Specifically, in this embodiment, the heat dissipation surface 131 of the heat sink 130 is provided with a plurality of grooves 132, so that the heat dissipation surface 131 of the heat sink 130 is uneven.

[0075] It is understood that in other embodiments, the heat dissipation surface 131 of the heat sink 130 is not limited to being uneven by means of the groove 132. For example, the heat dissipation surface 131 of the heat sink 130 can be set to a regular or irregular shape such as a wavy surface, so that the heat dissipation surface 131 of the heat sink 130 is uneven.

[0076] In this embodiment, the heat dissipation surface 131 of all heat sinks 130 is uneven. It is understood that in other embodiments, only some heat sinks 130 may have an uneven heat dissipation surface 131.

[0077] In this embodiment, the heat dissipation surface 131 of the heat sink 130 has a consistent shape. It is understood that in other embodiments, the shapes of the heat dissipation surface 131 of different heat sinks 130 may not be consistent. For example, the temperature at the center of the light-emitting region 1111 is typically higher than the temperature at the edges. Therefore, the area of ​​the heat dissipation surface 131 of the heat sink 130 at the center can be set to be larger than the area of ​​the heat dissipation surface 131 of the heat sink 130 at the edges, to better dissipate heat from the center and make the temperatures at different locations of the LED package structure 200 more similar.

[0078] It is understood that, in some other embodiments, the plurality of heat sinks 130 may also be arranged in an array, with uniform arrangement and heat dissipation. Of course, in some other embodiments, the arrangement of the plurality of heat sinks 130 is not limited to an array, and may also be arranged in other regular or irregular manner.

[0079] One embodiment of this application also provides a light-emitting device, which includes the LED packaging structure provided in any embodiment of this application.

[0080] The aforementioned light-emitting device reduces the size of the heat sink by providing multiple heat sinks on the second surface of the substrate, and the multiple heat sinks are distributed to facilitate the release of thermal stress and reduce warping.

[0081] The light-emitting device can be, but is not limited to, ambient lighting, and can be used on transportation equipment, or other equipment or scenarios where this is necessary.

[0082] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0083] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the embodiments of this application are not limited in this respect.

[0084] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

[0085] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An LED package structure, characterized in that, The LED packaging structure comprises: a substrate having a first surface and a second surface arranged oppositely; a light emitting unit arranged on the first surface of the substrate; and a plurality of heat dissipation plates arranged on the second surface of the substrate and in thermal contact with the substrate, and adjacent heat dissipation plates are arranged at intervals.

2. The LED package structure of claim 1, wherein, The heat dissipation plates are in a polygonal shape that can be densely arranged.

3. The LED package structure of claim 2, wherein, The surface of the heat dissipation plates away from the substrate is a heat dissipation surface, and at least part of the heat dissipation surfaces of the heat dissipation plates are in an uneven shape.

4. The LED package structure of claim 3, wherein, The heat dissipation surfaces of the heat dissipation plates are provided with a plurality of grooves. Alternatively, the heat dissipation surfaces of the heat dissipation plates are in a wavy surface shape.

5. The LED package structure of claim 2, wherein, At least part of the heat dissipation plates are in a regular hexagonal shape, a regular triangular shape, a right-angled triangular shape, a square shape or a rectangular shape.

6. The LED package structure of claim 1, wherein, The plurality of heat dissipation plates are arranged in an array.

7. The LED package structure according to any one of claims 1-6, wherein, The first surface of the substrate is provided with a first pad, and the second surface is provided with a second pad corresponding to the first pad one by one; a conductive hole is arranged through the substrate; the LED packaging structure further comprises a lead wire arranged through the conductive hole, and the lead wire is electrically connected to the first pad and the corresponding second pad at both ends, respectively.

8. The LED package structure of claim 7, wherein, The first surface of the substrate comprises a light emitting area and a first pad area arranged around the light emitting area; the second surface of the substrate comprises a heat dissipation area and a second pad area arranged around the heat dissipation area; The light emitting unit is arranged on the light emitting area; the first pad is arranged on the first pad area; the plurality of heat dissipation plates are arranged on the heat dissipation area, and the second pad is arranged on the second pad area.

9. The LED package structure of claim 7, wherein, The first pad and the corresponding second pad are arranged in a direction perpendicular to the substrate.

10. The LED package structure according to any one of claims 1-6, wherein, The light emitting unit comprises a light emitting chip and a fluorescent layer covering the light emitting chip; the fluorescent layer is used to change the color of the light emitted by the light emitting chip; Alternatively, the LED packaging structure comprises a plurality of light emitting units, part of the light emitting units comprising a light emitting chip and a fluorescent layer covering the light emitting chip; the fluorescent layer is used to change the color of the light emitted by the light emitting chip.

11. The LED package structure according to any one of claims 1-6, wherein, The LED packaging structure further comprises a white glue packaging structure arranged around the sidewall of the light emitting unit.

12. A light-emitting device, characterized in that, The LED packaging structure comprises any one of claims 1 to 11.

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