LED package structure and backlight source

Abstract

The present application discloses an LED package structure and a backlight source. The LED package 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 pad; the LED chip is arranged on the metal pad; the cup cavity is filled with fluorescent glue to cover the LED chip; and a cup opening of the cup cavity is covered with a light emergence adjustment structure layer, and the light emergence adjustment structure layer is used for adjusting the divergence angle of first emergent light of the LED chip, so that the divergence angle of the first emergent light is converted into a second angle from a first angle.

Description

An LED packaging structure and backlight

[0001] This application claims priority to Chinese Patent Application No. 202422143033.3, filed on August 30, 2024, entitled "An LED Packaging Structure and Backlight", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of light source technology, specifically to an LED packaging structure and a backlight. Background Technology

[0003] Currently, LED backlight structures are divided into two technical routes: COB (Chip On Board) and POB (Package On Board). POB has become the mainstream due to its advantages such as a mature upstream packaging industry, high production yield, and relatively low cost. Technical issues

[0004] Currently, LED chips using POB packaging require complex lenses, reflectors, reflector cups, and diffusion films in actual backlight systems to control the divergence angle of the light source in order to meet the requirements of backlight applications. However, the presence of these components greatly increases the complexity of the backlight system and results in high costs. Technical solutions

[0005] This invention provides an LED packaging structure and backlight that can effectively adjust the light emission divergence angle, thereby simplifying the backlight structure and reducing costs.

[0006] This application provides an LED packaging structure, which includes:

[0007] LED chips;

[0008] The bracket has a cup cavity, the bottom of which is provided with a metal pad. The LED chip is placed on the metal pad, and the cup cavity is filled with fluorescent glue to cover the LED chip.

[0009] The cup cavity is covered with a light emission adjustment structure layer, which is used to adjust the divergence angle of the first emitted light from the LED chip, so that the divergence angle of the first emitted light is changed from a first angle to a second angle.

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

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

[0012] In some embodiments of the LED packaging structure, the light emission adjustment structure layer includes a first film layer and a second film layer stacked together, wherein the refractive indices of the first film layer and the second film layer are different.

[0013] In some embodiments of the LED packaging structure, the light emission adjustment structure layer includes a plurality of alternatingly stacked first film layers and second film layers, wherein the refractive indices of the first film layers and the second film layers are different.

[0014] In some embodiments of the LED packaging structure, the light emission modulation structure layer includes a first microstructure layer.

[0015] In some embodiments of the LED packaging structure, the first microstructure layer includes a plurality of microstructures, the microstructures being cylindrical, prismatic, hemispherical, or pyramidal in shape.

[0016] In some embodiments of the LED packaging structure, the first microstructure layer includes a plurality of microstructures, wherein the plurality of microstructures are nanostructures.

[0017] In some embodiments of the LED packaging structure, the LED packaging structure further includes a light-emitting shaping structure layer, which is stacked on the light-emitting adjustment structure layer.

[0018] The light-emitting shaping structure layer is used to adjust the second emitted light rays emitted through the light-emitting adjustment structure layer.

[0019] In some embodiments of the LED packaging structure, the light-emitting shaping structure layer includes a grating structure.

[0020] In some embodiments of the LED packaging structure, the light-emitting shaping structure layer includes a second microstructure layer.

[0021] In some embodiments of the LED packaging structure, the second microstructure layer includes a plurality of microstructures, wherein the plurality of microstructures are nanostructures.

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

[0023] In some embodiments of the LED packaging structure, the light emission modulation structure layer includes a third microstructure layer.

[0024] In some embodiments of the LED packaging structure, the third microstructure layer includes multiple microstructures, which are nanostructures.

[0025] In some embodiments of the LED packaging structure, the LED packaging structure further includes a reflective structure layer, which is stacked on the light emission adjustment structure layer.

[0026] The reflective structure layer is used to reflect at least a portion of the second emitted light rays emitted through the light emission adjustment structure layer back to the light emission adjustment structure layer;

[0027] The light emission adjustment structure layer is also used to readjust the light reflected by the reflective structure layer.

[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, the inner wall of the cup cavity is provided with a plurality of protruding structures.

[0030] In some embodiments of the LED packaging structure, the protruding structure is a nanostructure.

[0031] This application embodiment also provides a backlight source, which includes multiple LED packaging structures, wherein the LED packaging structures include:

[0032] LED chips;

[0033] A bracket having a cup cavity, a metal pad being provided at the bottom of the cup cavity, an LED chip being disposed on the metal pad, and a fluorescent adhesive being filled in the cup cavity to cover the LED chip;

[0034] The cup cavity is covered with a light emission adjustment structure layer, which is used to adjust the divergence angle of the first emitted light from the LED chip, so that the divergence angle of the first emitted light is changed from a first angle to a second angle. Beneficial effects

[0035] This application provides an LED packaging structure and a backlight. The LED packaging structure includes a light emission adjustment layer that adjusts the light emission divergence angle of the LED chip, ensuring that the light emitted by the LED packaging structure meets the requirements for backlight display. Furthermore, when using this LED packaging structure to form a backlight, there is no need to add additional lenses, reflectors, or diffusion films, thus simplifying the backlight structure and reducing costs. Attached Figure Description

[0036] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0037] Figure 1 is a cross-sectional structural diagram of the first embodiment of the LED packaging structure provided in this application.

[0038] Figure 2 is a top view of the first embodiment of the light emission adjustment structure layer in the LED packaging structure provided in this application.

[0039] Figure 3 is a schematic diagram showing the relationship between the incident angle of light and the transmittance in the light emission adjustment structure layer of the LED packaging structure provided in the embodiment of this application.

[0040] Figure 4 is a schematic diagram showing the relationship between the incident angle of light and the energy of emitted light in the light emission adjustment structure layer of the LED packaging structure provided in the embodiment of this application.

[0041] Figure 5 is a schematic diagram of optical interference in the optical thin film layer of the LED packaging structure provided in the embodiment of this application.

[0042] Figure 6 is a schematic diagram of the light rays in Figure 2 provided in an embodiment of this application.

[0043] Figure 7 is a schematic diagram of the second embodiment of the light emission adjustment structure layer in the LED packaging structure provided in this application.

[0044] Figures 8 and 9 are schematic diagrams of the periodic structure in the LED packaging structure provided in the embodiments of this application.

[0045] Figure 10 is a schematic diagram of the third embodiment of the light emission adjustment structure layer in the LED packaging structure provided in this application.

[0046] Figure 11 is an optical schematic diagram of Figure 10 provided in an embodiment of this application.

[0047] Figure 12 is a cross-sectional structural diagram of the second embodiment of the LED packaging structure provided in this application.

[0048] Figure 13 is a schematic diagram of the light-emitting shaping structure layer and the light-emitting regulating structure layer in the LED packaging structure provided in the embodiment of this application.

[0049] Figure 14 is a schematic diagram of the first embodiment of the light-emitting shaping structure layer in the LED packaging structure provided in this application.

[0050] Figure 15 is a schematic diagram of the planar structure of the second embodiment of the light-emitting shaping structure layer in the LED packaging structure provided in this application.

[0051] Figure 16 is a three-dimensional structural diagram of the second embodiment of the light-emitting shaping structure layer in the LED packaging structure provided in this application.

[0052] Figure 17 is a schematic diagram of the second microstructure layer and the light emission adjustment structure layer in the LED packaging structure provided in the embodiment of this application.

[0053] Figure 18 is a schematic diagram of the third embodiment of the light-emitting shaping structure layer in the LED packaging structure provided in this application.

[0054] Figure 19 is a schematic diagram of the light rays in Figure 18 provided in an embodiment of this application.

[0055] Figure 20 is a schematic diagram of the fourth embodiment of the light-emitting shaping structure layer in the LED packaging structure provided in this application.

[0056] Figure 21 is a schematic diagram of the light rays in Figure 20 provided in an embodiment of this application.

[0057] Figure 22 is a schematic diagram of the reflective structure layer and the third microstructure layer in the LED packaging structure provided in the embodiment of this application.

[0058] Figure 23 is a schematic diagram of the first embodiment of the reflective structure layer in the LED packaging structure provided in this application.

[0059] Figure 24 is a schematic diagram of the fourth microstructure layer and the third microstructure layer in the LED packaging structure provided in the embodiment of this application.

[0060] Figure 25 is a schematic diagram of the protruding structure in the LED packaging structure provided in the embodiment of this application.

[0061] Reference numerals: 11, LED chip; 12, bracket; 13, metal pad; 14, phosphor adhesive; 15, light emission adjustment structure layer; 16, light emission shaping structure layer; 17, reflective structure layer; 18, protruding structure; 121, cup cavity; 131, first pad; 132, second pad; 151, first optical thin film layer; 152, third microstructure layer; 161, grating structure; 162, second microstructure layer; 171, second optical thin film layer; 172, fourth microstructure layer. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features thus defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0064] Referring to Figure 1, this embodiment provides an LED packaging structure, which includes an LED chip 11 and a support 12. The support 12 is a plastic support and has a cup cavity 121. A metal pad 13 is disposed at the bottom of the cup cavity 121, and the metal pad 13 is embedded in the support 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 phosphor 14 to cover the LED chip 11. The light emitted by the LED chip 11 excites the phosphor in the phosphor 14, so that the LED packaging structure emits white light.

[0065] The cup cavity 121 is covered with a light emission adjustment structure layer 15. The light emission adjustment structure layer 15 is used to adjust the divergence angle of the first emitted light from the LED chip 11, so that the divergence angle of the first emitted light is changed from a first angle to a second angle, so as to meet the requirements of backlight application.

[0066] In this embodiment, a light emission adjustment structure layer 15 is added to the LED packaging structure. The light emission adjustment structure layer 15 adjusts the light emission divergence angle of the LED chip 11 to ensure that the light emission of the LED packaging structure can meet the backlight display requirements. When using this LED packaging structure to form a backlight, there is no need to add additional structural layers such as lenses, reflectors, and diffusion films, thereby simplifying the backlight structure and reducing costs.

[0067] At the same time, by using this LED packaging structure to form a backlight, the use of additional lenses, reflectors and diffusion film layers can be reduced, which can avoid the absorption or reflection of light energy by the film layer on the LED structure, thereby reducing light energy loss, improving light utilization, reducing power consumption and improving luminous efficiency.

[0068] In some embodiments, the light emission 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 emission adjustment structure layer 15, the emission angle of the first emitted light can be reduced to [-15°, 15°], which means that the overall light emission divergence angle of the LED package structure is reduced. In this embodiment, by setting the light emission 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 emission extension characteristics and Lambertian characteristics of the LED chip 11.

[0069] In some embodiments, the light emission adjustment structure layer 15 is used to control the transmission of the first emitted light rays with an incident angle within a preset angle range. For example, the preset angle range can be 15° to 35°, or it can be less than 15°. That is, in this embodiment, the transmittance of the light emission adjustment structure layer 15 decreases as the incident angle increases. Therefore, when the incident angle of the first emitted light rays from the LED chip 11 exceeds the preset angle range, it cannot pass through the light emission adjustment structure layer 15. Thus, the light emission adjustment structure layer 15 can filter out the first emitted light rays with large incident angles, thereby controlling the divergence angle of the first emitted light rays.

[0070] Specifically, please refer to Figure 2. As an embodiment, the light emission adjustment structure layer 15 includes a plurality of stacked first optical thin film layers 151, and the refractive indices of adjacent first optical thin film layers 151 are different, thereby obtaining a film layer whose transmittance decreases as the incident angle increases.

[0071] For example, as shown in Figure 3, the transmittance drops sharply when the incident angle is greater than 10°, while the transmittance is close to 100% when the incident angle is less than 10°. Correspondingly, as shown in Figure 4, the smaller the absolute value of the incident angle, the higher the energy of the emitted light through the light emission adjustment structure layer 15; the energy of the emitted light is higher when the incident angle is between -10° and 10°. Therefore, in this embodiment, the divergence angle of the first emitted light is adjusted by depositing multiple layers of the first optical thin film 151.

[0072] In this multilayer first optical thin film layer 151, the materials of two adjacent optical thin film layers are different, which results in different refractive indices between adjacent optical thin film layers. That is, multiple optical thin film layers made of different materials can exist in the multilayer optical thin film layer.

[0073] Referring to Figures 5 and 6, the embodiments in this application can adjust the thickness of each first optical thin film layer 151 so that incident light rays at small angles interfere constructively, increasing transmittance and allowing all light to pass through; while incident light rays at large angles interfere destructively, decreasing transmittance and causing all light to be reflected. Therefore, for first outgoing light rays with large divergence angles, only those with incident angles within a preset angle range, such as less than 15°, can pass through after passing through multiple optical thin film layers, thus reducing the light divergence angle of the LED packaging structure.

[0074] As one embodiment, the light emission adjustment structure layer 15 may also include multiple alternating layers of first and second films, with the refractive indices of the first and second films being different. That is, in this embodiment, the light emission adjustment structure layer 15 is provided with only two optical thin film layers of different materials, and multiple layers of the two different optical thin film layers are alternately stacked.

[0075] In another embodiment, the light emission adjustment structure layer 15 includes a first film layer and a second film layer stacked together; wherein the refractive indices of the first film layer and the second film layer are different. That is, in this embodiment, the light emission adjustment structure layer 15 is provided with only two optical thin film layers made of two different materials, with one layer of each type of optical thin film layer.

[0076] Please refer to Figure 7. In the embodiments of this application, the thickness of the optical thin film layers can all be nanometer-scale, for example, the thickness of the optical thin film layer is subwavelength. Using nanometer-scale film layers, the interference and diffraction effects of light can be effectively modulated. Specifically, for multiple film layers, the thickness of each film layer can be precisely adjusted so that incident light rays within a specific angle range interfere constructively, increasing transmittance, while incident light rays within other angle ranges interfere destructively, decreasing transmittance, and being completely reflected. Therefore, for the first outgoing light rays with a large divergence angle, only those with an incident angle within a preset angle range, such as 15° to 35°, can pass through after passing through multiple optical thin film layers, thereby achieving the control of a specific divergence angle.

[0077] As one embodiment, the light emission adjustment structure layer 15 includes a first microstructure layer, which comprises multiple microstructures. The shapes of the microstructures are cylindrical, prismatic, hemispherical, or pyramidal. In this embodiment, the shapes of the multiple microstructures in the first microstructure layer can all be the same, that is, all the microstructures in the first microstructure layer are cylindrical or all are prismatic. Of course, the multiple microstructures in the first microstructure layer can have various combinations of different shapes, that is, some of the microstructures in the first microstructure layer are cylindrical, and some of the microstructures are prismatic. This application does not specifically limit this. In this embodiment, the maximum center distance between the microstructures is less than the wavelength of the emitted light from the LED chip 11, and the dimensions of each microstructure are smaller than the wavelength of the emitted light from the LED chip 11, so as to reduce the light emission divergence angle and realize the control of the divergence angle.

[0078] In some embodiments, the first microstructure layer includes multiple microstructures arranged in an array. For example, the multiple microstructures can be arranged in a rectangular array or in a concentric circular array, and each microstructure has the same shape and size. Taking a cylindrical shape as an example: As shown in Figure 8, the multiple microstructures in the first microstructure layer are arranged in a rectangular array, where p1 and p2 represent the center distance between two columns of microstructures. As shown in Figure 9, the multiple microstructures in the first microstructure layer are arranged in a concentric circular array, where p3 is the interval between the microstructure located at the center of the concentric circle and the adjacent concentric circle, and p4 is the interval between the second and third concentric circles.

[0079] In one embodiment, multiple microstructures are arranged in a rectangular array, with the center-to-center distance between two adjacent microstructures being less than the wavelength of the first emitted light; for example, this center-to-center distance is one-half or one-third of the wavelength. As shown in Figure 8, the center-to-center distance between two adjacent microstructures is shown as p1 and p2 in Figure 8. Multiple microstructures are arranged in an array, with p1 and p2 being equal and less than the wavelength of the first emitted light. If the emitted light from the LED structure is blue light, then the wavelength of the first emitted light is the blue light wavelength; if the emitted light from the LED structure is red light, then the wavelength of the first emitted light is the red light wavelength.

[0080] As one embodiment, multiple microstructures are arranged in a concentric circle array, with the interval between two adjacent concentric circles being smaller than the wavelength of the first emitted light; for example, this interval is one-half or one-third of the wavelength. As shown in Figure 9, the interval between two adjacent concentric circles is shown as p3 and p4 in Figure 9, where p3 and p4 are equal and smaller than the wavelength of the first emitted light. Similarly, if the emitted light from the LED structure is blue light, then the wavelength of the first emitted light is the blue light wavelength; if the emitted light from the LED structure is red light, then the wavelength of the first emitted light is the red light wavelength.

[0081] In this embodiment, multiple microstructures are arranged in an array, forming a certain arrangement period between them. As shown in Figures 10 and 11, taking a cylindrical microstructure array as an example, this embodiment can precisely control the arrangement period p0 in Figure 10, or the size of each cylinder, such as its height or radius, to regulate the array's response at different incident angles at specific wavelengths. Specifically, at small incident angles, the resonant transmission condition of the subwavelength unit periodic structure is satisfied, achieving high transmittance. At large incident angles, the resonant transmission condition cannot be satisfied, resulting in very low transmittance. Therefore, when the first outgoing light with a large divergence angle passes through this microstructure array, only incident angles within a preset angle range, such as less than 15°, can pass through, thereby reducing the divergence angle.

[0082] As one embodiment, the microstructure in the first microstructure layer is a nanostructure. In this embodiment, by setting the microstructure to a size at the same level as the wavelength, i.e., a nanoscale structure, the effect of light emission regulation is ensured to be more significant.

[0083] Please refer to Figure 12. In some embodiments, the LED packaging structure further includes a light-emitting shaping structure layer 16, which is stacked on the light-emitting adjustment structure layer 15. The light-emitting shaping structure layer 16 is used to adjust the second emitted light emitted through the light-emitting adjustment structure layer 15 to improve the light emission uniformity.

[0084] In this embodiment, the light-emitting shaping structure layer 16 shapes the second emitted light beam to achieve beam shaping and improve light emission uniformity. Specifically, in this embodiment, by setting the light-emitting shaping structure layer 16 to adjust the light spot uniformity of the LED structure, the shape of the light spot can be adjusted. For example, a square light spot can be converted into a circular light spot. Alternatively, the divergence angle of the second emitted light beam can be finely adjusted based on the light-emitting adjustment structure layer 15, for example, the divergence angle of the second emitted light beam can be finely adjusted from 15° to 18°.

[0085] Please refer to Figures 13 and 14 together. As one embodiment, the light-emitting shaping structure layer 16 includes a grating structure 161. For example, as shown in Figure 14, the grating structure 161 can be a symmetrical planar annular grating structure 161, which includes multiple annular sub-gratings. The width of each annular sub-grating can be different, and they are not arranged in a regular pattern, thus forming a non-periodic grating structure 161. As shown in Figures 15 and 16, it can also be a non-axisymmetric grating structure 161, which is not limited in this application. When a non-periodic grating structure 161 is provided, the emission direction of the incident light at each local position can be controlled, ultimately achieving the overall diffusion and uniform light effect of the incident light.

[0086] As one 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 spacing between each annular sub-grating is nanometer-sized. For the non-axisymmetric three-dimensional grating structure 161, the three-dimensional grating structure 161 is a nanometer-sized grating structure 161, thereby adapting to the wavelength level of the LED chip 11 and improving the light shaping effect.

[0087] Referring to Figure 17, in another embodiment, the light-emitting shaping structure layer 16 includes a second microstructure layer 162; the second microstructure layer 162 includes multiple microstructures, the shapes of which are cylindrical, prismatic, hemispherical, or pyramidal. In this embodiment, the shapes of the multiple microstructures in the first microstructure layer can all be the same, that is, all the multiple microstructures in the first microstructure layer are cylindrical or all are prismatic. Of course, there can be a variety of different combinations of shapes for the multiple microstructures in the first microstructure layer, that is, some of the microstructures in the first microstructure layer are cylindrical and others are prismatic; this application does not specifically limit this.

[0088] In some embodiments, the second microstructure layer 162 includes a plurality of microstructures arranged in an array. For example, the plurality of microstructures may be arranged in a rectangular array or in a concentric circular array. If it is necessary to achieve the purpose of light spot uniformity by fine-tuning the divergence angle of the second emitted light, 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 from the LED chip 11, and the dimensions of each corresponding microstructure are greater than the wavelength of the emitted light from the LED chip 11 and less than the maximum center distance.

[0089] Please refer to Figures 18 and 19 together. In this embodiment, multiple microstructures are arranged in an array, forming a certain arrangement period between the microstructures, which gives the second microstructure layer 162 diffraction characteristics. A beam of incident light at a specific angle can be diffracted to multiple angles, that is, multiple diffraction orders, after passing through the structural layer, presenting a wider angular range of light output, thus playing a diffusion role and uniformizing the light spot. 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 achieving the effect of diffused and uniform light.

[0090] Please refer to Figures 20 and 21 together. The microstructures in the second microstructure layer 162 can vary in size. As shown in Figure 20, in the cylindrical microstructure layer, the diameters of the cylinders are different, and the spacing between the cylinders is also different, presenting a non-periodic structural arrangement. In this embodiment, by controlling the exit direction of the incident light at each local cylinder position, the overall incident light diffusion and uniform light are ultimately achieved, as shown in Figure 21.

[0091] As one embodiment, multiple microstructures in the second microstructure layer 162 are nanostructures. By setting the microstructures to the same size as the wavelength, i.e., nanoscale structures, the effect of light shaping is ensured to be more significant.

[0092] In another embodiment, the light emission adjustment structure layer 15 can also increase the divergence angle of the first emitted light from the LED chip 11, thereby expanding the divergence angle of the entire LED package structure. That is, the second angle in this embodiment can also be greater than the first angle. When using this LED package structure to form a backlight, 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 for the thinner and lighter design of the product; on the other hand, it can reduce the use of additional lenses, reflectors, and diffusion film layers, which can avoid the absorption or reflection of light energy by the film layers on the LED package structure, thereby reducing light energy loss, improving light utilization, reducing power consumption, and achieving the purpose of improving luminous efficiency and visual effect.

[0093] Furthermore, when using this LED structure to form a backlight, there is no need to add additional structural layers such as lenses, reflectors, and diffusion films, which simplifies the backlight structure and reduces costs. Moreover, when using this LED packaging structure to form a backlight, compared to LED packaging structures with small divergence angles, a more sparsely arranged LED packaging structure can meet the brightness uniformity requirements, reducing the number of LED packaging structures and also achieving cost savings.

[0094] In this embodiment, the light emission adjustment structure layer 15 includes a third microstructure layer 152, which is the same as the second microstructure layer 162. The third microstructure layer 152 includes multiple microstructures, which are cylindrical, prismatic, hemispherical, or pyramidal in shape. The maximum center-to-center distance between the microstructures is greater than the wavelength of the light emitted from the LED chip 11. The dimensions of each microstructure are greater than the wavelength of the light emitted from the LED chip 11 but less than the maximum center-to-center distance, in order to achieve a light scattering effect and expand the light emission divergence angle of the LED structure.

[0095] In some embodiments, in the third microstructure layer 152, when multiple microstructures are arranged in a rectangular array, the center distance between two adjacent microstructures is greater than the wavelength of the first emitted light, such that the center distance is 1.5 times or 2 times the wavelength; in the third microstructure layer 152, when multiple microstructures are arranged in a concentric circle array, the interval between two adjacent concentric circles is greater than the wavelength of the first emitted light, such that the interval is 1.5 times or 2 times the wavelength.

[0096] Similarly, in this embodiment, multiple microstructures are arranged in an array, forming a certain arrangement period between the microstructures. 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 this embodiment, multiple microstructures are arranged in an array, forming a certain arrangement period between the microstructures, so that the third microstructure layer 152 has grating diffraction characteristics. Thus, the light passing through the third microstructure layer 152 is coupled to higher-order diffraction, thereby expanding the divergence angle.

[0097] As one embodiment, the multiple microstructures in the third microstructure layer 152 are nanostructures. In this embodiment, by setting the microstructures to be nanoscale structures with dimensions at the same level as the wavelength, the effect of expanding the divergence angle is ensured to be more significant. Specifically, when the multiple microstructures in the third microstructure layer 152 are arranged in an array, the size of the microstructure is smaller than the arrangement period formed by the array; when the multiple microstructures in the third microstructure layer 152 are not arranged in an array, the maximum center distance between the microstructures is greater than the wavelength of the emitted light from the LED chip 11, and the dimensions of each corresponding microstructure are greater than the wavelength of the emitted light from the LED chip, but the dimensions of each microstructure are smaller than the maximum center distance. 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 microstructure, and adjusting the height and base side length of the pyramidal microstructure.

[0098] Please refer to Figure 22. When the light emission adjustment structure layer 15 is used to increase the divergence angle of the first emitted light, i.e., when the second angle is greater than the first angle, the light emission adjustment structure layer 15 can be used to scatter the light. Correspondingly, the LED package structure also includes a reflective structure layer 17, which is stacked on the light emission adjustment structure layer 15. The reflective structure layer 17 is used to reflect at least a portion of the second emitted light emitted through the light emission adjustment structure layer 15 back to the light emission adjustment structure layer 15. The light emission adjustment structure layer 15 is also used to readjust the light reflected by the reflective structure layer 17 to further improve the light emission divergence angle of the LED package structure.

[0099] Specifically, in this embodiment, a reflective structure layer 17 is superimposed on the light emission adjustment structure layer 15. When the first emitted light from the LED chip 11 is adjusted by the light emission adjustment structure layer 15 to obtain the second emitted light, the second emitted light is reflected by the reflective structure layer 17. The light reflected by the reflective structure layer 17 will be adjusted again by the light emission adjustment structure layer 15. Thus, by setting the reflective structure layer 17 on the light emission adjustment structure layer 15, the light can be scattered multiple times by passing through the light emission adjustment structure layer 15, so that the LED packaging structure can obtain a larger divergence angle.

[0100] Referring to Figure 23, as one embodiment, the reflective structure layer 17 includes multiple stacked second optical thin film layers 171, and the refractive indices of adjacent second optical thin film layers 171 are different. In this embodiment, the thickness of each optical thin film layer can be adjusted so that incident light rays at small angles interfere constructively, increasing the transmittance and allowing all light to pass through; while incident light rays at large angles interfere destructively, decreasing the transmittance and causing all light to be reflected. Therefore, the first outgoing light rays with large divergence angles are reflected to the light emission adjustment structure layer 15 after passing through multiple layers of second optical thin film layers 171, in order to expand the light emission divergence angle of the LED packaging structure.

[0101] As one embodiment, the reflective structure layer 17 may also include multiple alternating layers of first and second films, with different refractive indices for the first and second films. That is, in this embodiment, the reflective structure layer 17 is provided with only two optical thin film layers of different materials, and multiple layers of the two different optical thin film layers are alternately stacked.

[0102] In another embodiment, the reflective structure layer 17 includes a first film layer and a second film layer stacked together, 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 provided with only two optical thin film layers made of two different materials, with one layer of each type of optical thin film layer.

[0103] Similarly, the thickness of the optical thin film layers in this embodiment can all be nanometer-scale. For example, the thickness of the optical thin film layer can be subwavelength. Using nanometer-scale film layers allows for effective modulation of light by utilizing the interference and diffraction effects of light. Specifically, for multiple film layers, the thickness of each film layer can be precisely adjusted so that the incident light within a specific angular range interferes destructively, reducing transmittance and causing complete reflection, thus facilitating multiple scattering of light.

[0104] Referring to Figure 24, as another embodiment, the reflective structure layer 17 includes a fourth microstructure layer 172; the fourth microstructure layer 172 includes multiple microstructures, the shapes of which are cylindrical, prismatic, hemispherical, or pyramidal. In this embodiment, the shapes of the multiple microstructures in the fourth microstructure layer 172 can all be the same, that is, all the microstructures in the fourth microstructure layer 172 are cylindrical or all are prismatic. Of course, the multiple microstructures in the fourth microstructure layer 172 can have various combinations of different shapes, that is, some of the microstructures in the fourth microstructure layer 172 are cylindrical, and some of the microstructures are prismatic; this application does not specifically limit this. In this embodiment, the maximum center distance between the microstructures is less than the wavelength of the emitted light from the LED chip 11, and the dimensions of each corresponding microstructure are less than the wavelength of the emitted light from the LED chip 11, so as to achieve effective reflection of light.

[0105] In some embodiments, the fourth microstructure layer 172 includes a plurality of microstructures arranged in an array. For example, the plurality of microstructures may be arranged in a rectangular array or in a concentric circular array. Taking a cylindrical shape as an example: as shown in Figure 8, the plurality of microstructures in the fourth microstructure layer 172 are arranged in a rectangular array, where p1 and p2 represent the center distance between two columns of microstructures. As shown in Figure 9, the plurality of microstructures in the fourth microstructure layer 172 are arranged in a concentric circular array, where p3 is the interval between the microstructure located at the center of the concentric circle and the adjacent concentric circle, and p4 is the interval between the second and third concentric circles.

[0106] Similarly, in this embodiment, multiple microstructures are arranged in an array, forming a certain arrangement period between the microstructures. This arrangement period can be less than the wavelength of the first emitted light, such as p1 and p2 being the same and less than the wavelength of the first emitted light, or p3 and p4 being the same and less than the wavelength of the first emitted light. In this embodiment, the size of the microstructures can be adjusted to give the fourth microstructure layer 172 different reflection effects, so as to further expand the light diffusion angle of the LED structure when combined with the scattering structure layer.

[0107] In some embodiments, the microstructure in the fourth microstructure layer 172 is a nanostructure; in this embodiment, by setting the microstructure to a size at the same level as the wavelength, i.e., a nanoscale structure, the effect of expanding the divergence angle is ensured to be more significant.

[0108] Please refer to Figure 25. In some embodiments, the inner wall of the cup cavity 121 is provided with a plurality of protruding structures 18. The first emitted light emitted from 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 emission adjustment structure layer 15 at the cup opening to ensure the uniformity of light emission of the LED packaging structure.

[0109] As one embodiment, the protruding structure 18 is a nanostructure. A single protruding structure 18, viewed from above towards the LED chip 11, is ring-shaped, and the width of this ring (as shown in Figure 24a) is at the nanometer level. Similarly, in a cross-sectional view along the direction from the cup rim towards the LED chip 11, the height of a single protruding structure 18 (as shown in Figure 24b) is also at the nanometer level; and the spacing between individual protruding structures 18 (as shown in Figure 24c) is also at the nanometer level. The multiple protruding structures 18 can be arranged in a regular pattern. For example, the width of the protruding structure 18 gradually decreases along the direction from the LED chip 11 towards the cup rim; the height of the protruding structure 18 gradually decreases along the direction from the LED chip 11 towards the cup rim; and the spacing between adjacent protruding structures 18 gradually decreases along the direction from the LED chip 11 towards the cup rim, etc. Specifically, this application does not impose specific limitations in this regard.

[0110] In this embodiment, by setting a nanostructure, the light emitted by the LED chip 11 can be more precisely modulated, which helps to improve the color uniformity caused by the conversion of white light by the phosphor 14, thereby improving the display effect.

[0111] This application embodiment also provides a backlight source, which includes a substrate on which multiple LED packaging structures as described above are attached. Since a light emission adjustment structure layer 15 is provided for each LED packaging structure, structures such as diffuser films, reflectors, or reflector cups can be omitted, effectively simplifying the backlight source structure and manufacturing process, thereby reducing costs. Simultaneously, reducing the use of lenses, reflectors, and diffuser film layers can prevent the absorption or reflection of light energy from the LED packaging structure by the film layers, thereby reducing light energy loss and improving visual efficiency. Because lenses, reflectors, and diffuser film layers occupy a large volume and weight, reducing their presence simplifies the backlight source structure, reduces the overall volume and weight, and lowers manufacturing difficulty and cost. Since the LED packaging structure has been described in detail above, it will not be repeated here.

[0112] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0113] The LED packaging structure provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An LED packaging structure, wherein, The LED packaging structure includes: LED chips; A bracket having a cup cavity, a metal pad being provided at the bottom of the cup cavity, an LED chip being disposed on the metal pad, and a fluorescent adhesive being filled in the cup cavity to cover the LED chip; The cup cavity is covered with a light emission adjustment structure layer, which is used to adjust the divergence angle of the first emitted light from the LED chip, so that the divergence angle of the first emitted light is changed from a first angle to a second angle.

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

3. The LED packaging structure according to claim 2, wherein, The light emission adjustment structure layer includes multiple stacked first optical thin film layers, and the refractive indices of adjacent first optical thin film layers are different.

4. The LED packaging structure according to claim 2, wherein, The light emission adjustment structure layer includes a first film layer and a second film layer stacked together, wherein the refractive indices of the first film layer and the second film layer are different.

5. The LED packaging structure according to claim 2, wherein, The light emission adjustment structure layer includes multiple alternating layers of first and second films, wherein the refractive indices of the first and second films are different.

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

7. The LED packaging structure according to claim 6, wherein, The first microstructure layer includes multiple microstructures, and the microstructures are cylindrical, prismatic, hemispherical, or pyramidal in shape.

8. The LED packaging structure according to claim 6, wherein, The first microstructure layer includes multiple microstructures, and the multiple microstructures are nanostructures.

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

10. The LED packaging structure according to claim 9, wherein, 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 multiple microstructures, and the multiple microstructures are nanostructures.

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 emission modulation structure layer includes a third microstructure layer.

15. The LED packaging structure according to claim 14, wherein, The third microstructure layer includes multiple microstructures, and the multiple microstructures are nanostructures.

16. The LED packaging structure according to claim 15, wherein, The LED packaging structure further includes a reflective structure layer, which is stacked on the light emission adjustment structure layer; The reflective structure layer is used to reflect at least a portion of the second emitted light rays emitted through the light emission adjustment structure layer back to the light emission adjustment structure layer; The light emission adjustment structure layer is also used to readjust the light reflected by the reflective structure layer.

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

18. The LED packaging structure according to claim 1, wherein, The inner wall of the cup cavity is surrounded by multiple protruding structures.

19. The LED packaging structure according to claim 18, wherein, The protruding structure is a nanostructure.

20. A backlight source, wherein, The backlight includes multiple LED packaging structures, and the LED packaging structures include: LED chips; A bracket having a cup cavity, a metal pad being provided at the bottom of the cup cavity, an LED chip being disposed on the metal pad, and a fluorescent adhesive being filled in the cup cavity to cover the LED chip; The cup cavity is covered with a light emission adjustment structure layer, which is used to adjust the divergence angle of the first emitted light from the LED chip, so that the divergence angle of the first emitted light is changed from a first angle to a second angle.

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