LED packaging structure and backlight source

Abstract

The utility model discloses an LED packaging structure and a backlight source, the LED packaging structure comprises an LED chip and a support, the support is provided with a cup cavity, the bottom of the cup cavity is provided with a metal bonding pad, the LED chip is arranged on the metal bonding pad, and the cup cavity is filled with fluorescent glue to cover the LED chip; wherein a cup opening of the cup cavity is covered with a light-emitting adjusting structure layer, and the light-emitting adjusting structure layer is used for adjusting the divergence angle of first emergent light rays of the LED chip, so that the divergence angle of the first emergent light rays is converted into a second angle from a first angle. The backlight source structure can be simplified, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of light sources, and particularly to an LED packaging structure and a backlight source. Background Art

[0002] Currently, the settings of LED backlight structures are divided into two technical routes: COB (Chip On Board) and POB (Package On Board). Due to the advantages of mature upstream packaging industry, high production yield, and relatively low cost, POB has become the mainstream.

[0003] Currently, for the LED lamp beads encapsulated by POB, in an actual backlight system, complex devices such as lenses, reflectors, reflector cups, and diffusion films are required to regulate the light divergence angle of the light source to meet the requirements of backlight applications. However, the presence of the above devices greatly increases the complexity of the backlight system and the cost is high.

[0004] Therefore, the current technology still needs to be improved. Summary of the Utility Model

[0005] The present application provides an LED packaging structure and a backlight source, which can effectively adjust the light divergence angle, simplify the backlight source structure, and reduce the cost.

[0006] The present application provides an LED packaging structure, and the LED packaging structure includes:

[0007] An LED chip;

[0008] A bracket having a cup cavity, a metal pad is provided at the bottom of the cup cavity, the LED chip is disposed on the metal pad, and the cup cavity is filled with a fluorescent glue to cover the LED chip;

[0009] Wherein, the cup opening of the cup cavity is covered with a light output adjustment structure layer, and the light output adjustment structure layer is used to adjust the divergence angle of the first emitted light of the LED chip, so that the divergence angle of the first emitted light is converted from a first angle to a second angle.

[0010] In the LED packaging structure of some embodiments, the second angle is smaller than the first angle.

[0011] In the LED packaging structure of some embodiments, the light output adjustment structure layer includes a plurality of first optical thin film layers stacked, and the refractive indexes between adjacent two first optical thin film layers are different.

[0012] In the LED packaging structure of some embodiments, the light output adjustment structure layer includes a first film layer and a second film layer stacked, and the refractive index of the first film layer is different from that of the second film layer.

[0013] In the LED packaging structure in some embodiments, the light output adjustment structure layer includes a plurality of first film layers and second film layers that are alternately stacked, and the refractive index of the first film layer is different from that of the second film layer.

[0014] In the LED packaging structure in some embodiments, the light output adjustment structure layer includes a first micro-structure layer.

[0015] In the LED packaging structure in some embodiments, the first micro-structure layer includes a plurality of micro-structures, and the shape of the micro-structures is cylindrical or prismatic or hemispherical or pyramidal.

[0016] In the LED packaging structure in some embodiments, the first micro-structure layer includes a plurality of micro-structures, and the plurality of micro-structures are nano-micro-structures.

[0017] In the LED packaging structure in some embodiments, the LED packaging structure further includes a light output shaping structure layer, and the light output shaping structure layer is stacked on the light output adjustment structure layer;

[0018] Among them, the light output shaping structure layer is used to adjust the second emitted light rays emitted from the light output adjustment structure layer.

[0019] In the LED packaging structure in some embodiments, the light output shaping structure layer includes a grating structure.

[0020] In the LED packaging structure in some embodiments, the light output shaping structure layer includes a second micro-structure layer.

[0021] In the LED packaging structure in some embodiments, the second micro-structure layer includes a plurality of micro-structures, and the plurality of micro-structures are nano-micro-structures.

[0022] In the LED packaging structure in some embodiments, the second angle is greater than the first angle.

[0023] In the LED packaging structure in some embodiments, the light output adjustment structure layer includes a third micro-structure layer.

[0024] In the LED packaging structure in some embodiments, the third micro-structure layer includes a plurality of micro-structures, and the plurality of micro-structures are nano-micro-structures.

[0025] In the LED packaging structure in some embodiments, the LED packaging structure further includes a reflection structure layer, and the reflection structure layer is stacked on the light output adjustment structure layer;

[0026] The reflection structure layer is used to reflect at least part of the second emitted light rays emitted from the light output adjustment structure layer to the light output adjustment structure layer;

[0027] The light output adjustment structure layer is further used to adjust the light rays reflected by the reflection structure layer again.

[0028] In some embodiments of the LED packaging structure, the reflective structure layer includes a fourth microstructure layer.

[0029] In some embodiments of the LED packaging structure, a plurality of protruding structures are disposed around the inner wall of the cup cavity.

[0030] In some embodiments of the LED packaging structure, the protruding structures are nano-microstructures.

[0031] An embodiment of the present application further provides a backlight, which includes a plurality of the above-mentioned LED packaging structures.

[0032] An LED packaging structure and a backlight provided by the present application, wherein an optical output adjustment structure layer is added to the LED packaging structure, and the optical output adjustment structure layer adjusts the light divergence angle of the LED chip to ensure that the light output of the LED packaging structure can meet the requirements of backlight display. When forming a backlight using this LED packaging structure, there is no need to add additional structural layers such as lenses, reflectors, and diffusion films, thereby simplifying the structure of the backlight and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following will, with reference to the drawings, make the technical solutions and other beneficial effects of the present application obvious through a detailed description of the specific embodiments of the present application.

[0034] Figure 1 It is a schematic cross-sectional structure diagram of the first embodiment of the LED packaging structure provided by an embodiment of the present application.

[0035] Figure 2 It is a top view schematic diagram of the first embodiment of the optical output adjustment structure layer in the LED packaging structure provided by an embodiment of the present application.

[0036] Figure 3 It is a schematic diagram showing the relationship between the light incident angle and the transmittance in the optical output adjustment structure layer of the LED packaging structure provided by an embodiment of the present application.

[0037] Figure 4 It is a schematic diagram showing the relationship between the light incident angle and the energy of the emitted light in the optical output adjustment structure layer of the LED packaging structure provided by an embodiment of the present application.

[0038] Figure 5 It is an optical interference schematic diagram of the optical thin film layer in the LED packaging structure provided by an embodiment of the present application.

[0039] Figure 6 For the present application provided by the embodiment Figure 2 of the light schematic diagram.

[0040] Figure 7 It is a schematic structural diagram of the second embodiment of the optical output adjustment structure layer in the LED packaging structure provided by an embodiment of the present application.

[0041] Figure 8 and Figure 9 is a schematic diagram of the period of the periodic structure in the LED packaging structure provided by the embodiment of the present application.

[0042] Figure 10 is a schematic structural diagram of the third embodiment of the light extraction adjustment structure layer in the LED packaging structure provided by the embodiment of the present application.

[0043] Figure 11 provided by the embodiment of the present application Figure 10 in the optical schematic diagram.

[0044] Figure 12 is a schematic cross-sectional structure diagram of the second embodiment in the LED packaging structure provided by the embodiment of the present application.

[0045] Figure 13 is a schematic diagram of the light extraction shaping structure layer and the light extraction adjustment structure layer in the LED packaging structure provided by the embodiment of the present application.

[0046] Figure 14 is a schematic structural diagram of the first embodiment of the light extraction shaping structure layer in the LED packaging structure provided by the embodiment of the present application.

[0047] Figure 15 is a schematic plan view of the second embodiment of the light extraction shaping structure layer in the LED packaging structure provided by the embodiment of the present application.

[0048] Figure 16 is a schematic three-dimensional structure diagram of the second embodiment of the light extraction shaping structure layer in the LED packaging structure provided by the embodiment of the present application.

[0049] Figure 17 is a schematic diagram of the second microstructure layer and the light extraction adjustment structure layer in the LED packaging structure provided by the embodiment of the present application.

[0050] Figure 18 is a schematic structural diagram of the third embodiment of the light extraction shaping structure layer in the LED packaging structure provided by the embodiment of the present application.

[0051] Figure 19 provided by the embodiment of the present application Figure 18 in the light ray schematic diagram.

[0052] Figure 20 is a schematic structural diagram of the fourth embodiment of the light extraction shaping structure layer in the LED packaging structure provided by the embodiment of the present application.

[0053] Figure 21 provided by the embodiment of the present application Figure 20 in the light ray schematic diagram.

[0054] Figure 22 Schematic diagram of the reflection structure layer and the third microstructure layer in the LED packaging structure provided by the embodiment of the present application.

[0055] Figure 23 Schematic diagram of the structure of the first embodiment of the reflection structure layer in the LED packaging structure provided by the embodiment of the present application.

[0056] Figure 24 Schematic diagram of the fourth microstructure layer and the third microstructure layer in the LED packaging structure provided by the embodiment of the present application.

[0057] Figure 25 Schematic diagram of the structure of the protruding structure in the LED packaging structure provided by the embodiment of the present application.

[0058] Reference numerals:

[0059] 11. LED chip; 12. Bracket; 13. Metal pad; 14. Fluorescent glue; 15. Light output adjustment structure layer; 16. Light output shaping structure; 17. Reflection structure layer; 18. Protruding structure;

[0060] 121. Cup cavity;

[0061] 131. First pad; 132. Second pad;

[0062] 151. First optical thin film layer; 152. Third microstructure layer;

[0063] 161. Grating structure; 162. Second microstructure layer;

[0064] 171. Second optical thin film layer; 172. Fourth microstructure layer. Detailed implementation manners

[0065] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present utility model, "a plurality" means two or more unless otherwise specifically defined.

[0067] Please refer to Figure 1, this embodiment provides an LED packaging structure, which includes an LED chip 11 and a bracket 12. The bracket 12 is a plastic bracket, and the bracket 12 is formed with a cup cavity 121. A metal pad 13 is provided at the bottom of the cup cavity 121. The metal pad 13 is embedded in the bracket 12 and exposed at the bottom of the cup. The metal pad 13 includes a first pad 131 and a second pad 132. The LED chip 11 is mounted on the metal pad 13, and the positive electrode of the LED chip 11 is connected to the first pad 131, and the negative electrode of the LED chip 11 is connected to the second pad 132. The cup cavity 121 is filled with a fluorescent glue 14 to cover the LED chip 11. The light emitted by the LED chip 11 excites the phosphor in the fluorescent glue 14, so that the LED packaging structure emits white light.

[0068] Wherein, the cup mouth of the cup cavity 121 is covered with a light output adjustment structure layer 15, and the light output adjustment structure layer 15 is used to adjust the divergence angle of the first emitted light of the LED chip 11, so that the divergence angle of the first emitted light is converted from a first angle to a second angle, in order to meet the requirements of backlight applications.

[0069] In the LED packaging structure of this embodiment, a light output adjustment structure layer 15 is added, and the light output adjustment structure layer 15 adjusts the light output divergence angle of the LED chip 11 to ensure that the light output of the LED packaging structure can meet backlight display. When using this LED packaging structure to form a backlight source, there is no need to add additional structural layers such as lenses, reflectors, and diffusion films, thereby simplifying the structure of the backlight source and reducing costs.

[0070] At the same time, using this LED packaging structure to form a backlight source and reducing the use of additional lens, reflector, and diffusion film layer structures can avoid the absorption or reflection of the light energy of the LED structure by the film layer, thereby reducing light energy loss, improving light utilization rate, reducing power consumption, and improving light efficiency.

[0071] In some embodiments, the light output adjustment structure layer 15 is used to reduce the divergence angle of the first emitted light, that is, the second angle in this embodiment is smaller than the first angle. For example, the divergence angle of the first emitted light emitted by the LED chip 11 is [-45°, 45°]. After passing through the light output adjustment structure layer 15, the emission angle of the first emitted light can be reduced to [-15°, 15°], that is, the overall light output divergence angle of the LED packaging structure is reduced. In this embodiment, by setting the light output adjustment structure layer 15 to adjust the divergence angle of the first emitted light, it is beneficial to alleviate the display problems caused by the light output expansion characteristic and Lambert characteristic of the LED chip 11.

[0072] In some embodiments, the light output adjusting structure layer 15 is used to control the transmission of the first outgoing light rays with the incident angle within a preset angle range. For example, the preset angle range can be 15° to 35°, or less than 15°, etc. That is, the light output adjusting structure layer 15 in this embodiment has a decreasing transmittance as the incident angle increases. Then, when the incident angle of the first outgoing light rays of the LED chip 11 exceeds the preset angle range, they cannot pass through the light output adjusting structure layer 15. Thus, the first outgoing light rays with large incident angles can be filtered out by the light output adjusting structure layer 15, and further the divergence angle of the first outgoing light rays can be controlled.

[0073] Specifically, please refer to Figure 2 , as an embodiment, the light output adjusting structure layer 15 includes a plurality of first optical thin film layers 151 stacked on top of each other, and the refractive indices between adjacent two first optical thin film layers 151 are different, thereby obtaining a film layer with a decreasing transmittance as the incident angle increases.

[0074] For example, as Figure 3 shown, when the incident angle is greater than 10°, the transmittance drops sharply, while when the incident angle is less than 10°, the transmittance is close to 100%. Correspondingly, as Figure 4 shown, the smaller the absolute value of the incident angle of the light rays, the higher the energy of the outgoing light rays corresponding to passing through the light output adjusting structure layer 15, and the higher the energy of the outgoing light rays when the incident angle is between -10° and 10°. Thus, in this embodiment, the divergence angle of the first outgoing light rays is adjusted by depositing multiple first optical thin film layers 151.

[0075] Among them, the materials of adjacent two optical thin film layers in the multiple first optical thin film layers 151 are different, thereby making the refractive indices between adjacent two optical thin film layers different. That is, there can be multiple optical thin film layers with different materials in the multiple optical thin film layers.

[0076] Please refer to Figure 5 and Figure 6 , in the embodiments of the present application, the thickness of each first optical thin film layer 151 can be adjusted so that the incident light rays at small angles interfere constructively, the transmittance increases, and all are transmitted; while the incident light rays at large angles interfere destructively, the transmittance decreases, and all are reflected. Therefore, for the first outgoing light rays with a large divergence angle, after passing through the multiple optical thin film layers, only those with the incident angle within the preset angle range, such as less than 15°, can pass through, realizing the reduction of the light output divergence angle of the LED packaging structure.

[0077] As an embodiment, the light output adjusting structure layer 15 can also include a plurality of first film layers and second film layers alternately stacked, and the refractive index of the first film layer is different from that of the second film layer. That is, in this embodiment, the light output adjusting structure layer 15 is only provided with two optical thin film layers of different materials, and the two different optical thin film layers are alternately stacked in multiple layers.

[0078] As another embodiment, the light output adjustment structure layer 15 includes a first film layer and a second film layer arranged in a stack; wherein, the refractive index of the first film layer is different from that of the second film layer. That is, in this embodiment, the light output adjustment structure layer 15 is only provided with two optical thin film layers of different materials, and each of the two different optical thin film layers is provided with one layer.

[0079] Please refer to Figure 7 together. In the embodiments of the present application, the thickness of the optical thin film layer can all adopt a thickness in the nanometer size. For example, the thickness of the optical thin film layer is sub-wavelength. By using a film layer at the nanometer size level, the interference and diffraction effects of light can be utilized to effectively adjust the light. Specifically, for multiple film layers, the thickness of each film layer can be precisely adjusted so that the incident light within a specific angle range interferes constructively, increasing the transmittance, and the incident light in all other angle ranges interferes destructively, reducing the transmittance and being all reflected. Therefore, for the first outgoing light with a large divergence angle, only the incident light with an incident angle within a preset angle range, such as between 15° and 35°, can pass through after passing through multiple optical thin film layers, thereby realizing the regulation of a specific divergence angle.

[0080] As an embodiment, the light output adjustment structure layer 15 includes a first micro-structure layer, and the first micro-structure layer includes a plurality of micro-structures. The shape of the micro-structure is cylindrical or prismatic or hemispherical or pyramidal. In this embodiment, the shapes of the plurality of micro-structures in the first micro-structure layer can be the same, that is, the plurality of micro-structures in the first micro-structure layer are all cylindrical or all prismatic. Of course, there can be a combination of various different shapes among the plurality of micro-structures in the first micro-structure layer, that is, a part of the micro-structures in the first micro-structure layer have a cylindrical shape, and another part of the micro-structures have a prismatic shape. The present application does not make specific limitations on this. In this embodiment, the maximum center distance between the micro-structures is less than the wavelength of the outgoing light of the LED chip 11, and the respective dimensions of the corresponding micro-structures are less than the wavelength of the outgoing light of the LED chip 11, so as to reduce the light output divergence angle and realize the regulation of the divergence angle.

[0081] In some embodiments, the first micro-structure layer includes a plurality of micro-structures, and the plurality of micro-structures are arranged in an array. For example, the plurality of micro-structures are arranged in a rectangular array, or can also be arranged in a concentric circle array, and the shape and size of each micro-structure are the same. Taking the shape of the micro-structure as cylindrical as an example: as Figure 8 shown, the plurality of micro-structures in the first micro-structure layer are arranged in a rectangular array, and p1 and p2 represent the center distance between two columns of micro-structures. As Figure 9 shown, the plurality of micro-structures in the first micro-structure layer are arranged in a concentric circle array, p3 is the interval between the micro-structure located at the center of the concentric circles and the adjacent concentric circle, and p4 is the interval between the second concentric circle and the third concentric circle.

[0082] As an embodiment, a plurality of microstructures are arranged in a rectangular array, and the center distance between two adjacent microstructures is less than the wavelength of the first emitted light; for example, the center distance is one-half or one-third of the wavelength. As Figure 8 shown, the center distance between two adjacent microstructures is as Figure 8 shown by p1 and p2 in

[0083] As an embodiment, a plurality of microstructures are arranged in a concentric circle array, and the interval between two adjacent concentric circles is less than the wavelength of the first emitted light; for example, the interval is one-half or one-third of the wavelength. As Figure 9 shown, the interval between two adjacent concentric circles is as Figure 9 shown by p3 and p4 in

[0084] In the embodiment of the present application, a plurality of microstructures are arranged in an array, and a certain arrangement period is formed between the microstructures. As Figure 10 and Figure 11 shown, taking the cylindrical microstructure array as an example, in this embodiment, by precisely controlling the arrangement period such as Figure 10 p0 in

[0085] or the size of each cylinder, such as the height or radius of the cylinder, etc., the response of the array at different incident angles for a specific wavelength can be regulated. Specifically, at a small incident angle, the resonant transmission condition of the sub-wavelength unit periodic structure is satisfied, and a very high transmittance is achieved. At a large incident angle, the resonant transmission condition cannot be satisfied, and the transmittance is very low. Then, when the first emitted light with a large divergence angle passes through the microstructure array, only the incident angles within a preset angle range, such as less than 15°, can pass through, thereby realizing the reduction of the divergence angle.

[0086] Please refer to Figure 12 , in some embodiments, the LED packaging structure further includes a light output shaping structure layer 16, and the light output shaping structure layer 16 is stacked on the light output adjusting structure layer 15; wherein, the light output shaping structure layer 16 is used to adjust the second emitted light emitted by the light output adjusting structure layer 15 to improve the light output uniformity.

[0087] In this embodiment, the light-emitting shaping structure layer 16 shapes the second emitted light beam to achieve beam shaping and improve the light-emitting uniformity. Specifically, in this embodiment, the light-emitting shaping structure layer 16 is provided to adjust the spot uniformity of the LED structure, and the shape of the spot can be adjusted. For example, a square spot can be converted into a circular spot, or the divergence angle of the second emitted light beam can be finely adjusted on the basis of the light-emitting adjustment structure layer 15. For example, the divergence angle of the second emitted light beam of 15° can be finely adjusted to 18°.

[0088] Please refer to Figure 13 and Figure 14 , as an embodiment, the light-emitting shaping structure layer 16 includes a grating structure 161. For example, as Figure 14 shown, the grating structure 161 can be a symmetric planar annular grating structure 161. For this planar annular grating structure 161, it includes a plurality of annular sub-gratings, and the width of each annular sub-grating can be different and is arranged without regularity, that is, a non-periodic grating structure 161 is formed; as Figure 15 and Figure 16 shown, it can also be an axially asymmetric grating structure 161, and this application does not make any limitation thereto. When the non-periodic grating structure 161 is provided, the outgoing direction of the incident light at each local position can be controlled, and finally the diffusion and light homogenization effect of the incident light can be achieved as a whole.

[0089] As an embodiment, the grating structure 161 is a nano-grating structure 161. For the planar annular grating structure 161, the width of each annular sub-grating or the interval size between each annular sub-grating is of nano size; for the axially asymmetric three-dimensional grating structure 161, the three-dimensional grating structure 161 is a nano-sized grating structure 161, so as to be adapted to the wavelength level of the LED chip 11 and further improve the light-emitting shaping effect.

[0090] Please refer to Figure 17 , as another embodiment, the light-emitting shaping structure layer 16 includes a second micro-structure layer 162; the second micro-structure layer 162 includes a plurality of micro-structures, and the shape of the micro-structures is cylindrical or prismatic or hemispherical or pyramidal. In this embodiment, the shapes of the plurality of micro-structures in the first micro-structure layer can be the same, that is, the plurality of micro-structures in the first micro-structure layer are all cylindrical or all prismatic. Of course, there can be a combination of various different shapes among the plurality of micro-structures in the first micro-structure layer, that is, a part of the micro-structures in the first micro-structure layer are cylindrical in shape, and another part of the micro-structures are prismatic in shape, and this application does not make specific limitations thereto.

[0091] In some embodiments, the second microstructure layer 162 includes a plurality of microstructures arranged in an array. For example, the plurality of microstructures are arranged in a rectangular array or can be arranged in a concentric circle array. If it is necessary to finely adjust the divergence angle of the second emitted light to achieve the purpose of uniform light spot, in this embodiment, the maximum center distance between the microstructures in the second microstructure layer 162 can be greater than the wavelength of the emitted light of the LED chip 11, and the respective dimensions of the corresponding microstructures are greater than the wavelength of the emitted light of the LED chip 11 and less than the maximum center distance.

[0092] Please refer to Figure 18 and Figure 19 together. In the embodiments of the present application, a plurality of microstructures are arranged in an array, and a certain arrangement period is formed between the microstructures, so that the second microstructure layer 162 has diffraction characteristics; a beam of incident light at a specific angle can be diffracted into multiple angles after passing through the structure layer, that is, on multiple diffraction orders, presenting a larger angular range of light emission, playing a role in diffusion to make the light spot uniform. At the same time, by precisely controlling the arrangement period or the size of the microstructures, the intensity of different diffraction orders can be controlled, further realizing the function of diffusion and light homogenization.

[0093] Please refer to Figure 20 and Figure 21 together. The microstructures in the second microstructure layer 162 can have different sizes. For example, in the cylindrical microstructure layer shown in Figure 20 , the diameters of the respective cylinders are different, and the intervals between the respective cylinders are also different, presenting a non-periodic structure arrangement. In this embodiment, by controlling the emission direction of the incident light at each local cylinder position, the diffusion and light homogenization of the overall incident light are finally realized, and the corresponding principle is as shown in Figure 21 .

[0094] As an embodiment, the plurality of microstructures in the second microstructure layer 162 are nano-microstructures. By setting the microstructures to structures with the same order of magnitude as the wavelength, that is, nano-scale structures, the effect of light shaping of the emitted light can be ensured to be more significant.

[0095] In another embodiment, the light output adjustment structure layer 15 can also increase the divergence angle of the first emitted light of the LED chip 11, thereby expanding the divergence angle of the entire LED package structure. That is, the second angle in the embodiments of the present application can also be greater than the first angle. Then, when using this LED package structure to form a backlight source, on the one hand, it can ensure that the LED package structure achieves a larger divergence angle at a shorter optical distance, which is beneficial to the thin and light design of the product; on the other hand, it can reduce the use of additional lens, reflector, and diffusion film layer structures, and can avoid the absorption or reflection of the light energy of the LED package structure by the film layer, thereby reducing the light energy loss, improving the light utilization rate, reducing the power consumption, and achieving the purpose of improving the light efficiency and visual effect.

[0096] In addition, when forming a backlight source using this LED structure, there is no need to add additional structural layers such as lenses, reflectors, and diffusion films, which can also simplify the structure of the backlight source and reduce costs. When forming a backlight source using this LED packaging structure, compared with an LED packaging structure with a small divergence angle, a more sparsely arranged LED packaging structure can meet the brightness uniformity, reduce the number of LED packaging structures, and also achieve the purpose of cost savings.

[0097] The light output adjustment structure layer 15 in this embodiment includes a third micro-structure layer 152. Similar to the second micro-structure layer 162, the third micro-structure layer 152 includes a plurality of micro-structures, and the shape of the micro-structures is cylindrical or prismatic or hemispherical or pyramidal. Among them, the maximum center distance between the micro-structures is greater than the wavelength of the emitted light of the LED chip 11, and the respective dimensions of the corresponding micro-structures are greater than the wavelength of the emitted light of the LED chip 11 and less than the maximum center distance, so as to facilitate the scattering effect of light and expand the light output divergence angle of the LED structure.

[0098] In some embodiments, when a plurality of micro-structures in the third micro-structure layer 152 are arranged in a rectangular array, the center distance between adjacent two micro-structures is greater than the wavelength of the first emitted light, and this center distance is 1.5 times or 2 times the wavelength; when a plurality of micro-structures in the third micro-structure layer 152 are arranged in a concentric circle array, the interval between adjacent two concentric circles is greater than the wavelength of the first emitted light, such as this interval being 1.5 times or 2 times the wavelength.

[0099] Similarly, in this embodiment, a plurality of micro-structures are arranged in an array, and a certain arrangement period is formed between the micro-structures; this arrangement period can be greater than the wavelength of the first emitted light, such as p1 and p2 being the same and greater than the wavelength of the first emitted light, or p3 and p4 being the same and greater than the wavelength of the first emitted light. In the embodiment of the present application, a plurality of micro-structures are arranged in an array, and a certain arrangement period is formed between the micro-structures, so that the third micro-structure layer 152 has grating diffraction characteristics, and thus the light passing through this structure layer is coupled to higher-order diffraction by the third micro-structure layer 152, thereby realizing the expansion of the divergence angle.

[0100] As an embodiment, the multiple microstructures in the third microstructure layer 152 are nano-microstructures. In this embodiment, by setting the microstructures to be structures with dimensions at the same level as the wavelength, i.e., nano-scale structures, it is ensured that the effect of expanding the divergence angle is more significant. Specifically, when the multiple microstructures in the third microstructure layer 152 are arranged in an array, the size of the microstructures is smaller than the arrangement period formed by the array arrangement; when the multiple microstructures in the third microstructure layer 152 are arranged non-arrayedly, the maximum center distance between the microstructures is greater than the wavelength of the emitted light of the LED chip 11, and each dimension of the corresponding microstructures is greater than the wavelength of the emitted light of the LED chip, but each dimension of the microstructures is smaller than the maximum center distance. Among them, the angle of expanding the divergence angle can be adjusted by adjusting the size of the microstructures; for example, adjusting the height and thickness of the cylindrical microstructures, adjusting the height and bottom side length of the pyramid-shaped microstructures, etc.

[0101] Please refer to Figure 22 , when the light-emitting adjustment structure layer 15 is used to increase the divergence angle of the first emitted light, i.e., the second angle is greater than the first angle, the light-emitting adjustment structure layer 15 at this time can be used to scatter the light. Correspondingly, the LED packaging structure further includes a reflection structure layer 17, and the reflection structure layer 17 is stacked on the light-emitting adjustment structure layer 15; the reflection structure layer 17 is used to reflect at least part of the second emitted light emitted from the light-emitting adjustment structure layer 15 to the light-emitting adjustment structure layer 15, and the light-emitting adjustment structure layer 15 is further used to readjust the light reflected by the reflection structure layer 17 to further increase the light-emitting divergence angle of the LED packaging structure.

[0102] Specifically, in this embodiment, the reflection structure layer 17 is stacked on the light-emitting adjustment structure layer 15. When the first emitted light of the LED chip 11 is adjusted by the light-emitting adjustment structure layer 15 to obtain the second emitted light, the second emitted light is reflected by the reflection structure layer 17, and the light reflected by the reflection structure layer 17 will reach the light-emitting adjustment structure layer 15 again and be adjusted twice. Therefore, by setting the reflection structure layer 17 on the light-emitting adjustment structure layer 15, the light can pass through the light-emitting adjustment structure layer 15 multiple times for scattering, so that the LED packaging structure can obtain a larger divergence angle.

[0103] Please refer to Figure 23 , as an embodiment, the reflection structure layer 17 includes a plurality of second optical thin film layers 171 stacked, and the refractive indices between adjacent two second optical thin film layers 171 are different. In this embodiment, the thickness of each optical thin film layer can be adjusted so that the incident light at a small angle interferes constructively, the transmittance increases, and all of it is transmitted; while the incident light at a large angle interferes destructively, the transmittance decreases, and all of it is reflected. Therefore, the first emitted light with a large divergence angle will be reflected to the light-emitting adjustment structure layer 15 after passing through the multiple second optical thin film layers 171, so as to facilitate expanding the light-emitting divergence angle of the LED packaging structure.

[0104] As an embodiment, the reflective structure layer 17 may also include a plurality of first film layers and second film layers alternately stacked, and the refractive indices of the first film layer and the second film layer are different. That is, in this embodiment, the reflective structure layer 17 is only provided with optical thin film layers of two different materials, and the two different optical thin film layers are alternately stacked in multiple layers.

[0105] As another embodiment, the reflective structure layer 17 includes a first film layer and a second film layer stacked, wherein the refractive indices of the first film layer and the second film layer are different. That is, in this embodiment, the reflective structure layer 17 is only provided with optical thin film layers of two different materials, and one layer of each of the two different optical thin film layers is provided.

[0106] Similarly, the thickness of the optical thin film layer in this embodiment can all adopt a thickness of nanometer size. For example, the thickness of the optical thin film layer is sub-wavelength. By using a film layer of nanometer size level, the interference and diffraction effects of light can be utilized to effectively adjust light. Specifically, for multiple film layers, the thickness of each film layer can be precisely adjusted so that the incident light within a specific angle range interferes destructively, the transmittance decreases, and all is reflected, so as to facilitate multiple scattering of light.

[0107] Please refer to Figure 24 , as another embodiment, the reflective structure layer 17 includes a fourth microstructure layer 172; the fourth microstructure layer 172 includes a plurality of microstructures, and the shapes of the microstructures are cylindrical or prismatic or hemispherical or pyramidal. In this embodiment, the shapes of the plurality of microstructures in the fourth microstructure layer 172 may be the same, that is, the plurality of microstructures in the fourth microstructure layer 172 are all cylindrical or all prismatic. Of course, there can be a combination of various different shapes among the plurality of microstructures in the fourth microstructure layer 172, that is, a part of the microstructures in the fourth microstructure layer 172 are cylindrical in shape, and another part of the microstructures are prismatic in shape. The present application does not make specific limitations in this regard. In this embodiment, the maximum center distance between the microstructures is less than the wavelength of the emitted light of the LED chip 11, and the respective dimensions of the corresponding microstructures are less than the wavelength of the emitted light of the LED chip 11, so as to facilitate effective reflection of light.

[0108] In some embodiments, the fourth microstructure layer 172 includes a plurality of microstructures, and the plurality of microstructures are arranged in an array. For example, the plurality of microstructures are arranged in a rectangular array or can be arranged in a concentric circle array. Taking the shape of the microstructure as cylindrical as an example: as Figure 8 shown, the plurality of microstructures in the fourth microstructure layer 172 are arranged in a rectangular array, and p1 and p2 represent the center distance between two columns of microstructures. As Figure 9As shown, the multiple microstructures in the fourth microstructure layer 172 are arranged in a concentric circle array. p3 is the interval between the microstructure at the center of the concentric circles and the adjacent concentric circles, and p4 is the interval between the second concentric circle and the third concentric circle.

[0109] Similarly, in this embodiment, multiple microstructures are arranged in an array, and a certain arrangement period is formed between the microstructures; this arrangement period can be smaller than the wavelength of the first outgoing light. For example, p1 and p2 are the same and smaller than the wavelength of the first outgoing light, or p3 and p4 are the same and smaller than the wavelength of the first outgoing light. Among them, in this embodiment, the reflection effect of the fourth microstructure layer 172 can be adjusted by adjusting the size of the microstructures, so as to be combined with the scattering structure layer to further expand the light-emitting diffusion angle of the LED structure.

[0110] In some embodiments, the microstructures in the fourth microstructure layer 172 are nano-microstructures; in this embodiment, by setting the microstructures to be structures with the same order of magnitude as the wavelength, that is, nano-scale structures, it is ensured that the effect of expanding the divergence angle is more significant.

[0111] Please refer to Figure 25 simultaneously. In some embodiments, a plurality of protruding structures 18 are arranged around the inner wall of the cup cavity 121. The first outgoing light emitted by the LED chip 11 to the inner wall of the cup cavity 121 is modulated by the protruding structures 18 and cooperates with the light-emitting adjustment structure layer 15 at the cup mouth to ensure the light-emitting uniformity of the LED packaging structure.

[0112] As an embodiment, the protruding structures 18 are nano-microstructures. The top view schematic diagram of a single protruding structure 18 from the cup mouth towards the LED chip 11 direction is annular, and the width dimension of this ring (such as Figure 24 a) is a nano-scale dimension. Similarly, in the cross-sectional schematic diagram along the cup mouth towards the LED chip 11 direction, the height dimension of a single protruding structure 18 (such as Figure 24 b) is also a nano-scale dimension; and the interval between single protruding structures 18 (such as Figure 24 c) is also a nano-scale dimension. Among them, the multiple protruding structures 18 can be arranged regularly. For example, along the direction from the LED chip 11 towards the cup mouth, the width of the protruding structures 18 gradually decreases; or along the direction from the LED chip 11 towards the cup mouth, the height of the protruding structures 18 gradually decreases; or along the direction from the LED chip 11 towards the cup mouth, the interval between adjacent protruding structures 18 gradually decreases, etc. Specifically, this application does not make specific limitations on this.

[0113] In this embodiment, by setting nano-microstructures, it is convenient to achieve more refined modulation of the light emitted by the LED chip 11, which is beneficial to improving the color non-uniformity characteristics brought by the conversion of the fluorescent glue 14 into white light, and further improving the display effect.

[0114] The embodiment of the present application further provides a backlight source, which includes a substrate, and a plurality of the above-mentioned LED packaging structures are attached to the substrate; since a light output adjustment structure layer 15 is provided for each LED packaging structure, structures such as a diffusion film, a reflector or a reflector cup can be omitted, which can effectively simplify the structure and manufacturing process of the backlight source, thereby reducing costs. At the same time, reducing the use of lens, reflector and diffusion film layer structures can avoid the absorption or reflection of the light energy of the LED packaging structure by the film layer, thereby reducing light energy loss, so as to improve the visual effect; since the lens, reflector and diffusion film layer occupy a large volume and weight, reducing their settings can simplify the structure of the backlight source, reduce the overall volume and weight, and reduce the process difficulty and cost. Since the LED packaging structure has been described in detail above, it will not be elaborated here.

[0115] In the above embodiments, the descriptions of the respective embodiments have their own focuses. For the parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0116] The LED packaging structure provided by the embodiments of the present application has been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An LED packaging structure, characterized in that, The LED packaging structure includes: an LED chip; a bracket having a cup cavity with a metal pad disposed at the bottom of the cup cavity, the LED chip being disposed on the metal pad, and the cup cavity being filled with a fluorescent glue to cover the LED chip; wherein, a light-emitting adjustment structure layer covers the cup opening of the cup cavity, and the light-emitting adjustment structure layer is configured to adjust the divergence angle of the first emitted light of the LED chip, such that the divergence angle of the first emitted light is converted from a first angle to a second angle.

2. The LED packaging structure according to claim 1, characterized in that, The second angle is smaller than the first angle.

3. The LED packaging structure according to claim 2, characterized in that The light-emitting adjustment structure layer includes a plurality of first optical film layers stacked, and the refractive indices between adjacent two of the first optical film layers are different.

4. The LED packaging structure according to claim 2, wherein The light-emitting adjustment structure layer includes a first film layer and a second film layer stacked, and the refractive index of the first film layer is different from the refractive index of the second film layer.

5. The LED packaging structure according to claim 2, wherein, The light-emitting adjustment structure layer includes a plurality of first film layers and second film layers alternately stacked, and the refractive index of the first film layer is different from the refractive index of the second film layer.

6. The LED packaging structure according to claim 2, wherein, The light-emitting adjustment structure layer includes a first microstructure layer.

7. The LED packaging structure according to claim 6, wherein The first microstructure layer includes a plurality of microstructures, and the shape of the microstructure is cylindrical or prismatic or hemispherical or pyramidal.

8. The LED packaging structure according to claim 6, wherein, The first microstructure layer includes a plurality of microstructures, and the plurality of microstructures are nano-microstructures.

9. The LED packaging structure according to claim 8, wherein, The LED packaging structure further includes a light-emitting shaping structure layer stacked on the light-emitting adjustment structure layer; wherein, the light-emitting shaping structure layer is configured to adjust the second emitted light emitted from the light-emitting adjustment structure layer.

10. The LED packaging structure according to claim 9, characterized in that, The light-emitting shaping structure layer includes a grating structure.

11. The LED packaging structure according to claim 9, wherein, The light-emitting shaping structure layer includes a second microstructure layer.

12. The LED packaging structure according to claim 11, wherein, The second microstructure layer includes a plurality of microstructures, and the plurality of microstructures are nano-microstructures.

13. The LED packaging structure according to claim 1, wherein, The second angle is greater than the first angle.

14. The LED packaging structure according to claim 13, wherein, The light-emitting adjustment structure layer includes a third microstructure layer.

15. The LED packaging structure according to claim 14, wherein, The third microstructure layer includes a plurality of microstructures, and the plurality of microstructures are nano-microstructures.

16. The LED packaging structure according to claim 15, wherein, The LED packaging structure further includes a reflection structure layer stacked on the light-emitting adjustment structure layer; the reflection structure layer is configured to reflect at least part of the second emitted light among the second emitted light emitted from the light-emitting adjustment structure layer to the light-emitting adjustment structure layer; the light-emitting adjustment structure layer is further configured to adjust the light reflected by the reflection structure layer again.

17. The LED packaging structure according to claim 16, wherein The reflection structure layer includes a fourth microstructure layer.

18. The LED packaging structure according to any one of claims 1-17, characterized in that, A plurality of protruding structures are disposed around the inner wall of the cup cavity.

19. The LED packaging structure according to claim 18, wherein, The protruding structures are nano-microstructures.

20. A backlight, characterized in that, The backlight source includes a plurality of LED packaging structures according to any one of claims 1-19.

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