LED package structure and display device

Abstract

The utility model relates to display equipment technical field especially LED packaging structure and display device, LED packaging structure includes wiring layer, with the LED chip of wiring layer electricity connection, the filling layer that sets up around LED chip, set up in the sapphire layer that LED chip far away from wiring layer one side and LED chip are pasted, LED packaging structure still includes the fluorescent layer that sets up around filling layer and sapphire layer, fluorescent layer sets up around filling layer and sapphire layer, realizes spectrum conversion, when the blue light that LED chip emits irradiates on fluorescent layer, fluorescent layer absorbs part blue light and emits other color light, and the white light that mixes with blue light is obtained to realize MIP white light product, make the light that emits from LED packaging structure more uniform, improve illumination quality and visual comfort.

Description

Technical Field

[0001] This utility model relates to the field of display equipment technology, and in particular to an LED packaging structure and display device. Background Technology

[0002] MIP, or "MicroLED in Package," is a packaging technology based on Mini LED or Micro LED. It involves cutting a Micro LED chip into individual small packages, splitting and mixing the light in these small packages, and then performing a surface mount process to create a display device.

[0003] Currently, MicroLED MIP products only offer monochrome or RGB direct-display solutions. The monochrome solution uses a flip-chip structure bonded to the driver wiring layer, but the fabrication process for MicroLED flip-chips is complex and the assembly efficiency is low. The RGB direct-display solution assembles three different blue, green, and red MicroLEDs onto the same driver wiring layer, mixing them to emit light and forming independent full-color light. This requires the fabrication of blue, green, and red MicroLED chips, making the manufacturing process relatively complex. Therefore, more solutions are needed for white MIP products. Utility Model Content

[0004] To address the problem of complex manufacturing processes in existing MIP white light products, this invention provides an LED packaging structure and display device.

[0005] The present invention provides an LED packaging structure that solves the technical problem by including a wiring layer, an LED chip electrically connected to the wiring layer, a filling layer surrounding the LED chip, and a sapphire layer disposed on the side of the LED chip away from the wiring layer and attached to the LED chip. The LED packaging structure further includes a phosphor layer surrounding the filling layer and the sapphire layer.

[0006] Preferably, the side of the sapphire layer facing away from the LED chip is the light-emitting surface, and the projected area of ​​the light-emitting surface based on the wiring layer is larger than the projected area of ​​the LED chip based on the wiring layer.

[0007] Preferably, the wiring layer includes solder joints disposed on the side away from the LED chip.

[0008] Preferably, the fluorescent layer includes a top surface adjacent to the light-emitting surface and four side surfaces adjacent to the top surface, the side surfaces being directly bonded to the filling layer, the wiring layer, the solder joints and the sapphire layer.

[0009] Preferably, the LED packaging structure further includes a bonding layer disposed on the side of the LED chip near the sapphire layer.

[0010] Preferably, the distance between the upper surface of the bonding layer and the wiring layer is greater than or equal to the distance between the LED chip and the wiring layer.

[0011] Preferably, the thickness of the sapphire layer is between 20um and 400um.

[0012] Preferably, the planar projected area of ​​the fluorescent layer relative to the wiring layer is greater than the planar projected area of ​​the sapphire layer relative to the wiring layer.

[0013] Preferably, the fluorescent layer comprises a fluorescent material or a quantum dot material, and the LED chip is a blue LED chip.

[0014] To solve the above-mentioned technical problems, this utility model provides another technical solution as follows: a display device, including a carrier device and an LED encapsulation structure as described above disposed on the carrier device.

[0015] Compared with the prior art, the LED packaging structure and display device provided by this utility model have the following advantages:

[0016] 1. The LED packaging structure provided in this utility model embodiment requires the separate fabrication of blue, green, and red MicroLED chips for existing RGB direct display solutions, which is complex and costly. The LED chip in this application is a blue light chip. By setting a phosphor layer around the filler layer and the sapphire layer, the RGB direct display solution is replaced, simplifying the LED packaging structure fabrication process. The conversion of light color is achieved by the phosphor layer surrounding the filler layer and the sapphire layer, eliminating the need for separate fabrication, sorting, and matching processes for red and green chips, and reducing the material complexity of MIP packaging.

[0017] 2. The LED packaging structure provided in this embodiment of the present invention features a MicroLED chip with an extremely small size, typically ranging from a few micrometers to tens of micrometers. The light-emitting area is concentrated in the quantum well layer at the core of the chip, while the light-emitting surface of the sapphire layer is larger than the planar projection area of ​​the LED chip, thereby increasing the light-emitting area and reducing total internal reflection loss at the edge of the LED chip. The sapphire layer forms an extended light-transmitting area around the LED chip, allowing light emitted from the side of the LED chip to be exported through the extended portion of the sapphire layer, resulting in uniform light distribution and meeting the requirements of MIP products.

[0018] 3. In the LED packaging structure provided in this embodiment of the utility model, the wiring layer has solder joints on the side away from the LED chip, which ensures the reliability of electrical connection and process compatibility. The solder joints away from the LED chip are more easily exposed on the surface of the LED packaging structure, which facilitates welding or pressing with the pins of external driving circuits or flexible circuit boards (FPCs), reducing assembly difficulty.

[0019] 4. In the LED packaging structure provided in this embodiment, the blue light emitted from the light-emitting surface of the sapphire layer is directly and perpendicularly incident on the top surface of the phosphor layer, ensuring that the blue light in the main light-emitting direction is efficiently absorbed and converted. The phosphor layer includes four sides adjacent to the top surface. The phosphor layer on the sides wraps the filling layer, wiring layer, solder joints and sapphire layer. There are gaps or reflective structures around the connection between the filling layer and wiring layer and the connection between the solder joints and wiring layer. The phosphor layer adheres to the filling layer, wiring layer and solder joints, intercepting and capturing the blue light leaking through these structural sides, ensuring that more blue light is absorbed and converted by the phosphor layer, reducing light loss.

[0020] 5. The LED packaging structure provided in this embodiment of the present invention features an extremely small MicroLED chip. The sapphire layer serves as an optical functional layer and is tightly bonded to the LED chip to achieve efficient light guiding. The bonding layer firmly connects the two, preventing displacement and gaps between the LED chip and the sapphire layer during subsequent beam splitting, beam mixing, or module assembly. This ensures the structural integrity of the LED packaging structure and optimizes the transmission of light from the LED chip to the sapphire layer.

[0021] 6. In the LED packaging structure provided in this embodiment of the present invention, the MicroLED chip and the bonding layer are located between the sapphire layer and the wiring layer, and the distances from both to the wiring layer are equal, that is, the upper surface of the bonding layer is at the same height. The uniform height ensures that the flatness of the bonding layer and the upper surface of the LED chip is consistent, ensuring the flatness of the LED packaging structure, improving structural stability, optimizing the light transmission path in the multilayer structure, and reducing optical loss.

[0022] 7. In the LED packaging structure provided in this utility model embodiment, sapphire (Al2O3) has high hardness and mechanical stability and is a commonly used substrate material for GaN-based semiconductor thin films. The thickness of 20um–400μm can ensure that the sapphire layer has sufficient rigidity to support the epitaxially grown semiconductor thin film above, provide stable structural support, and ensure the mechanical reliability of the device. At the same time, sapphire with appropriate thickness can balance heat dissipation performance and maintain the working stability of the LED packaging structure.

[0023] 8. In the LED packaging structure provided in this embodiment of the present invention, the area of ​​the phosphor layer is larger than that of the sapphire layer, forming a wrap-around coverage, ensuring that the blue light emitted by the LED chip is completely converted by the phosphor layer and avoiding blue light leakage; when light is emitted from the sapphire layer, it will be refracted due to the difference in refractive index of the medium. The phosphor layer area is larger than that of the sapphire layer, reserving redundant space to cover the deflected light path, providing a larger diffusion angle, compensating for the angle deviation of light propagation, and improving conversion efficiency.

[0024] 9. The LED packaging structure provided in this embodiment of the present invention uses fluorescent material or quantum dot material for the fluorescent layer, and is paired with a blue LED chip. The process is simplified and the color performance is improved through light color conversion. It also meets the requirements of miniaturized LED packaging structure and realizes a high-efficiency solution for full-color display or white light output. The fluorescent material can be YAG:Ce³+ phosphor, which absorbs blue light and emits yellow light. The blue light and yellow light are mixed to form white light. The quantum dot can be CdSe / ZnS, which emits green light or red light through size control.

[0025] 10. The present invention also provides a display device, including a carrier device and an LED encapsulation structure as described above disposed on the carrier device, which has the same beneficial effects as the LED encapsulation structure, and will not be described again here. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a side view of the LED packaging structure provided in the first embodiment of the present invention. Figure 1 .

[0028] Figure 2 This is a side view of the LED packaging structure provided in the first embodiment of the present invention. Figure 2 .

[0029] Figure 3 This is a schematic diagram of the optical path of the LED packaging structure provided in the first embodiment of this utility model.

[0030] Figure 4 This is a top view of the display device provided in the second embodiment of this utility model.

[0031] Explanation of reference numerals in the attached diagram:

[0032] 100. LED packaging structure; 200. Display device; 201. Supporting device;

[0033] 1. LED chip; 2. Wiring layer; 3. Filler layer; 4. Sapphire layer; 5. Phosphor layer; 6. Bonding layer.

[0034] 21. Solder joint; 41. Polished surface; 51. Top surface; 52. Side surface. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0036] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0037] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0038] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0039] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0040] Please see Figures 1-3The first embodiment of this utility model provides an LED packaging structure 100, including a wiring layer 2, an LED chip 1 electrically connected to the wiring layer 2, a filling layer 3 surrounding the LED chip 1, and a sapphire layer 4 disposed on the side of the LED chip 1 away from the wiring layer and attached to the LED chip 1. The LED packaging structure 100 also includes a phosphor layer 5 surrounding the filling layer 3 and the sapphire layer 4.

[0041] Micro LEDs are LED chips with dimensions in the micrometer range. The LED packaging structure 100 provided by this invention uses Micro LEDs and has self-emissive characteristics, high brightness, long lifespan, and low power consumption. It is commonly used in automotive displays, televisions, and other applications.

[0042] Understandably, Micro LED in Package (MIP) is a technology that integrates Micro LED chip 1 with driving circuits, optical structures, etc. Due to the small size of Micro LED chip 1, it is difficult to connect it directly to external circuits. Therefore, the implementation of full-color display or high-complexity display in Micro LED MIP products is still relatively limited.

[0043] The LED packaging structure 100 provided by this utility model adopts a mass transfer of monochrome Micro LED chips 1 followed by rewiring and color conversion technology to achieve a white light solution for Micro LED MIP products.

[0044] Specifically, the wiring layer 2 (RDL) enables the electrical connection between the LED chip 1 and the driving circuit, while providing a physical support substrate for the fill layer 3 and the sapphire layer 4. Through the standardized wiring layer 2 design, the connection difficulty between the LED chip 1 and the external circuit is reduced, and the current conduction efficiency is improved.

[0045] LED chip 1 is a light source, and can be a blue, red, or green LED chip 1. In this embodiment, a blue LED chip 1 is used. A fluorescent layer 5 is disposed around the filling layer 3 and the sapphire layer 4. The blue light emitted by the blue LED chip 1 is absorbed by the fluorescent layer 5. The fluorescent layer 5 absorbs the blue light and converts it into yellow light. The yellow light and blue light are mixed to form white light. The blue light and yellow fluorescence excitation is an indirect way to realize white light, which significantly improves the white light output efficiency.

[0046] It should be noted that the fluorescent layer 5 is an integrated covering structure that completely surrounds the four outer peripheral sides of the filling layer 3 and the upper surface and four sides of the sapphire layer 4.

[0047] The fluorescent layer 5 is a wall of a certain height that extends downward along the perimeter of the sapphire layer 4. The bottom of the wall bends toward the lower surface of the wiring layer 2, covering part of the lower surface of the wiring layer 2, to ensure full-area conversion of the light emitted from the LED chip 1.

[0048] Furthermore, the bonding of the fluorescent layer 5 with the filler layer 3, sapphire layer 4 and wiring layer 2 is achieved through a dispensing process to ensure optical coupling efficiency.

[0049] The filling layer 3 surrounds the LED chip 1, fills the gap between the LED chip 1 and the sapphire layer 4, wraps the edge of the LED chip 1, isolates moisture and dust, and fixes the position of the LED chip 1.

[0050] As a non-limiting specific implementation, the filling layer 3 is made of transparent silicone or epoxy resin material to reduce interface reflection and blue light loss when the LED chip 1 emits light, so that the blue light can be transmitted to the fluorescent layer 5 more evenly, ensuring uniform fluorescence excitation and avoiding white light spots or color deviation.

[0051] The sapphire layer 4 is bonded to the LED chip 1 on the side away from the wiring layer 2. As an optical window of the LED chip 1, it has the characteristics of high light transmittance, high temperature resistance and high mechanical strength. The crystal structure of sapphire can reduce the scattering of light at the interface between the LED chip 1 and the air, so that the blue light is more concentrated on the phosphor layer 5, avoiding light leakage and improving the forward light emission efficiency of white light.

[0052] Furthermore, the side of the sapphire layer 4 facing away from the LED chip 1 is the light-emitting surface 41, and the planar projection area of ​​the light-emitting surface 41 based on the wiring layer is larger than the planar projection area of ​​the LED chip 1 based on the wiring layer.

[0053] Understandably, the planar projected area of ​​the light-emitting surface 41 based on the wiring layer is larger than the planar projected area of ​​the LED chip 1 based on the wiring layer. The LED chip 1 is a small light source with angular divergence. When the LED chip 1 emits light, some of the light will be emitted to the side 52. The larger area of ​​the light-emitting surface 41 covers the light emitted from the side 52 of the LED chip 1, preventing the light from being blocked or absorbed by the edge of the LED packaging structure 100, thereby improving the overall light emission efficiency, improving the light uniformity, and avoiding the light spot effect.

[0054] Furthermore, the planar projected area of ​​the fluorescent layer 5 relative to the wiring layer 2 is larger than the planar projected area of ​​the sapphire layer 4 relative to the wiring layer 2.

[0055] Understandably, the planar projected area of ​​the phosphor layer 5 is larger than that of the sapphire layer 4, ensuring that the blue light emitted from the front or side 52 of the LED chip 1 is fully covered by the phosphor layer 5, reducing light leakage. At the same time, it allows the light excited by the phosphor material in the phosphor layer 5 to mix more evenly, improving the color accuracy and consistency of the white light. The phosphor layer 5 is bonded to the filler layer 3 and the wiring layer 2. The larger projected area can increase the bonding contact area, improve structural stability, and reduce delamination caused by thermal expansion and contraction. Meanwhile, the area redundancy is compatible with the small positioning errors of the sapphire layer 4 during the packaging process, improving the yield of mass production.

[0056] Furthermore, in this embodiment, the packaging process of the phosphor layer 5 in the LED packaging structure 100 is as follows: first, the initially packaged LED chip 1 unit is cut to obtain independent small units, and then the color conversion layer process is precisely implemented on each small unit to ensure that the color conversion layer only covers the target area and avoids damage to the color conversion layer caused by cutting.

[0057] Before cutting, LED chip 1 is a whole wafer. If the color conversion layer is molded first and then cut, the cutting process may damage the integrity of the color conversion layer, and the debris generated during cutting will contaminate the color conversion layer and affect the optical performance.

[0058] The specific method of the color conversion process is as follows: a coating with light color conversion function is formed on the cut LED chip 1 independent unit, and phosphor particles are uniformly attached to the surface of the LED chip 1 unit by high-precision deposition technology. In this embodiment, the LED chip 1 unit includes wiring layer 2, LED chip 1, filling layer 3, sapphire layer 4, and wiring layer 2 includes solder joints 21 set on the side away from LED chip 1.

[0059] Furthermore, the deposition technology includes, but is not limited to, phosphor deposition, phosphor coating, molding and other implementation methods. In this application, no specific limitation is made on the method of color conversion process, as long as it can achieve the overlay color conversion attachment of the LED chip 1 unit including wiring layer 2, LED chip 1, filling layer 3, sapphire layer 4 and solder joint 21.

[0060] In one non-limiting embodiment, the fluorescent layer 5 may also employ a layered deposition design during the deposition process.

[0061] Specifically, the fluorescent layer 5 deposits a high concentration of phosphor in the region near the filling layer 3 to quickly convert stray light scattered around the filling layer 3 and reduce color shift; the fluorescent layer 5 deposits a low concentration of phosphor in the region near the sapphire layer 4 to finely adjust the color of the high-brightness blue light emitted from the sapphire layer 4 and ensure uniform light color.

[0062] It should be noted that the specific content and distribution of phosphor in the fluorescent layer 5 are not specifically limited in this utility model, as long as the fluorescent layer 5 can achieve full coverage of the wiring layer 2, LED chip 1, filling layer 3, sapphire layer 4 and solder joint 21.

[0063] Furthermore, the wiring layer 2 includes solder joints 21 disposed on the side away from the LED chip 1.

[0064] Understandably, solder joint 21 is a metal connection point on the side of wiring layer 2 away from LED chip 1. It is the interface for the LED package structure 100 to achieve electrical connection and mechanical fixation with external circuit. As a standardized connection interface, solder joint 21 can be adapted to automated welding equipment. It does not require direct operation on the tiny electrodes of LED chip 1, which reduces the requirements for assembly accuracy, optimizes current distribution, reduces electrode damage, is compatible with multiple connection methods, and enhances design flexibility.

[0065] Specifically, the LED packaging structure 100 in this embodiment includes at least two sets of solder joints 21. The solder joints 21 are connected to the electrodes of the LED chip 1 through the wiring layer 2. The external circuit supplies power to the LED chip 1 through the at least two sets of solder joints 21 to achieve electrical conduction and provide mechanical fixing points.

[0066] Furthermore, the fluorescent layer 5 includes a top surface 51 adjacent to the light-emitting surface 41, and four side surfaces 52 adjacent to the top surface 51. The side surfaces 52 are directly bonded to the filling layer 3, the wiring layer 2, the solder joints 21 and the sapphire layer 4.

[0067] Understandably, the original light emission of LED chip 1 will be emitted in multiple directions, including the forward direction perpendicular to the light-emitting surface 41 and the lateral light emission to the side 52. The top surface 51 of the phosphor layer 5 is directly bonded to the light-emitting surface 41 of the sapphire layer 4. The four sides 52 are directly bonded to the filling layer 3, wiring layer 2, solder joint 21 and the side 52 of the sapphire layer 4 to achieve all-round coverage. The phosphor in the phosphor layer 5 converts blue light into target light, such as yellow light, and mixes it with the converted light emitted in the forward direction to improve the overall light utilization rate. The direct bonding without air gaps can reduce light reflection at the interface of different media, allowing more light to pass through the phosphor layer 5 and participate in the conversion, avoiding interface reflection loss.

[0068] Furthermore, the LED packaging structure 100 also includes a bonding layer 6 disposed on the side of the LED chip 1 near the sapphire layer 4.

[0069] Understandably, the bonding layer 6 is disposed on the side of the LED chip 1 close to the sapphire layer 4, that is, between the LED chip 1 and the sapphire layer 4. It is the core interface layer connecting the LED chip 1 and the sapphire layer 4. The LED chip 1 is epitaxially grown on the sapphire substrate, but the bonding force between the epitaxial LED chip 1 and the sapphire layer 4 is weak and it is easy to peel off due to vibration, thermal stress, etc. The bonding layer 6 firmly connects the two by adhesive bonding.

[0070] Furthermore, the distance A between the upper surface of the bonding layer 6 and the wiring layer 2 (e.g., ...) Figure 3 In this context, A) is greater than or equal to the distance a between LED chip 1 and wiring layer 2 (e.g., ...). Figure 3 (a) in the middle.

[0071] Understandably, the distance A from the upper surface of bonding layer 6 to wiring layer 2 (e.g.) Figure 3 In the diagram, A) is equidistant from the distance a from LED chip 1 to wiring layer 2 (e.g., ...). Figure 3 a) or the distance A from the upper surface of bonding layer 6 to wiring layer 2 (e.g. Figure 3 In this case, A) is greater than the distance a from LED chip 1 to wiring layer 2 (e.g., Figure 3 (a) In this context, the height of the bonding layer 6 matches the thickness of the LED chip 1, forming an equal-height bonding, thereby achieving a stable connection between the LED chip 1 and the sapphire layer 4, efficient heat dissipation, and optimized light path.

[0072] Specifically, the bonding layer 6 ensures a stable mechanical connection between the LED chip 1 and the sapphire layer 4, ensuring precise fit and avoiding stress concentration. The equal height fills the gaps at the connection interface, reducing light loss and improving light extraction efficiency. The bonding layer 6 uses a transparent adhesive, such as silicone, with a refractive index between the epitaxial layer of the LED chip 1 and the sapphire layer, forming a gradient refractive index transition. This reduces Fresnel reflection of light at the interface between the LED chip 1 and the bonding layer 6 and the sapphire layer 4, allowing more light to enter the sapphire layer 4 and then be extracted through the phosphor layer 5.

[0073] Furthermore, the thickness of sapphire layer 4 ranges from 20um to 400um.

[0074] Understandably, limiting the thickness of the sapphire layer 4 to the range of 20μm-400μm ensures that light has sufficient paths to diffuse within the sapphire layer 4, avoids light spot concentration, and adapts to different LED chip sizes. A sapphire layer 4 with a thickness of more than 20μm can withstand mechanical stress during packaging processes such as cutting and transfer, preventing the LED packaging structure from shattering. A sapphire layer 4 with a thickness of less than 400μm is easier for mass transfer equipment to grasp, while reducing cutting energy consumption.

[0075] Specifically, the thickness of the sapphire layer 4 is matched to the light conversion requirements of the phosphor layer 5. If the sapphire layer 4 is too thin, the light from the LED chip 1 will directly impact the phosphor layer 5, and the local light intensity will be too high, causing fluorescence saturation. If the sapphire layer 4 is too thick, the light will be reflected multiple times within the sapphire layer 4, and some light will be absorbed before reaching the phosphor layer 5, reducing the conversion efficiency. A thickness of 20μm-400μm ensures that the light enters the phosphor layer 5 uniformly, improving the white light mixing effect.

[0076] Furthermore, the fluorescent layer 5 includes fluorescent materials or quantum dot materials, and the LED chip 1 is a blue LED chip 1.

[0077] Understandably, the LED packaging structure 100 provided by this utility model is an efficient solution to achieve white light or full color. It replaces the complex RGB direct display solution by using blue light to excite light in conjunction with color conversion materials. The blue LED chip 1 emits 440-460nm blue light to excite other colors of light, and the blue light mixes with the other colors of light to form white light.

[0078] Specifically, the fluorescent material can be YAG:Ce³⁺ phosphor, which emits yellow light. Blue light and yellow light are mixed to form white light, thus achieving white light. The quantum dot material can be InP / ZnS quantum dots, which emit green or red light. When mixed with blue light, they achieve a wider color gamut, thus achieving full color.

[0079] Please refer to 4. The second embodiment of this utility model provides a display device 200, including a carrier device 201 and an LED encapsulation structure 100 as in the first embodiment disposed on the carrier device 201.

[0080] The display device 200 has the same beneficial effects as the LED packaging structure 100 of the first embodiment, which will not be described again here.

[0081] Optionally, the display device 200 may include various lamps on vehicle and transportation equipment, as well as general lighting equipment, display and backlighting equipment, and consumer electronics and home appliances, depending on the usage scenario and function. Specifically, the arrangement method and number of LED packaging structures 100 on the carrier device 201 are not limited according to different application scenarios.

[0082] Compared with the prior art, the LED packaging structure and display device provided by this utility model have the following advantages:

[0083] 1. The LED packaging structure provided in this utility model embodiment requires the separate fabrication of blue, green, and red MicroLED chips for existing RGB direct display solutions, which is complex and costly. The LED chip in this application is a blue light chip. By setting a phosphor layer around the filler layer and the sapphire layer, the RGB direct display solution is replaced, simplifying the LED packaging structure fabrication process. The conversion of light color is achieved by the phosphor layer surrounding the filler layer and the sapphire layer, eliminating the need for separate fabrication, sorting, and matching processes for red and green chips, and reducing the material complexity of MIP packaging.

[0084] 2. The LED packaging structure provided in this embodiment of the present invention features a MicroLED chip with an extremely small size, typically ranging from a few micrometers to tens of micrometers. The light-emitting area is concentrated in the quantum well layer at the core of the chip, while the light-emitting surface of the sapphire layer is larger than the planar projection area of ​​the LED chip, thereby increasing the light-emitting area and reducing total internal reflection loss at the edge of the LED chip. The sapphire layer forms an extended light-transmitting area around the LED chip, allowing light emitted from the side of the LED chip to be exported through the extended portion of the sapphire layer, resulting in uniform light distribution and meeting the requirements of MIP products.

[0085] 3. In the LED packaging structure provided in this embodiment of the utility model, the wiring layer has solder joints on the side away from the LED chip, which ensures the reliability of electrical connection and process compatibility. The solder joints away from the LED chip are more easily exposed on the surface of the LED packaging structure, which facilitates welding or pressing with the pins of external driving circuits or flexible circuit boards (FPCs), reducing assembly difficulty.

[0086] 4. In the LED packaging structure provided in this embodiment, the blue light emitted from the light-emitting surface of the sapphire layer is directly and perpendicularly incident on the top surface of the phosphor layer, ensuring that the blue light in the main light-emitting direction is efficiently absorbed and converted. The phosphor layer includes four sides adjacent to the top surface. The phosphor layer on the sides wraps the filling layer, wiring layer, solder joints and sapphire layer. There are gaps or reflective structures around the connection between the filling layer and wiring layer and the connection between the solder joints and wiring layer. The phosphor layer adheres to the filling layer, wiring layer and solder joints, intercepting and capturing the blue light leaking through these structural sides, ensuring that more blue light is absorbed and converted by the phosphor layer, reducing light loss.

[0087] 5. The LED packaging structure provided in this embodiment of the present invention features an extremely small MicroLED chip. The sapphire layer serves as an optical functional layer and is tightly bonded to the LED chip to achieve efficient light guiding. The bonding layer firmly connects the two, preventing displacement and gaps between the LED chip and the sapphire layer during subsequent beam splitting, beam mixing, or module assembly. This ensures the structural integrity of the LED packaging structure and optimizes the transmission of light from the LED chip to the sapphire layer.

[0088] 6. In the LED packaging structure provided in this embodiment of the present invention, the MicroLED chip and the bonding layer are located between the sapphire layer and the wiring layer, and the distances from both to the wiring layer are equal. That is, the upper surface of the bonding layer and the top surface of the chip are at the same height. The uniform height ensures that the flatness of the bonding layer and the upper surface of the LED chip are consistent, ensuring the flatness of the LED packaging structure, improving the structural stability, optimizing the light transmission path in the multilayer structure, and reducing optical loss.

[0089] 7. In the LED packaging structure provided in this utility model embodiment, sapphire (Al2O3) has high hardness and mechanical stability and is a commonly used substrate material for GaN-based semiconductor thin films. The thickness of 20μm–400μm can ensure that the sapphire layer has sufficient rigidity to support the epitaxially grown semiconductor thin film above, provide stable structural support, and ensure the mechanical reliability of the device. At the same time, the appropriate thickness of sapphire can balance heat dissipation performance and maintain the working stability of the LED packaging structure.

[0090] 8. In the LED packaging structure provided in this embodiment of the present invention, the area of ​​the phosphor layer is larger than that of the sapphire layer, forming a wrap-around coverage, ensuring that the blue light emitted by the LED chip is completely converted by the phosphor layer and avoiding blue light leakage; when light is emitted from the sapphire layer, it will be refracted due to the difference in refractive index of the medium. The phosphor layer area is larger than that of the sapphire layer, reserving redundant space to cover the deflected light path, providing a larger diffusion angle, compensating for the angle deviation of light propagation, and improving conversion efficiency.

[0091] 9. The LED packaging structure provided in this embodiment of the present invention uses fluorescent material or quantum dot material for the fluorescent layer, and is paired with a blue LED chip. The process is simplified and the color performance is improved through light color conversion. It also meets the requirements of miniaturized LED packaging structure and realizes a high-efficiency solution for full-color display or white light output. The fluorescent material can be YAG:Ce³+ phosphor, which absorbs blue light and emits yellow light. The blue light and yellow light are mixed to form white light. The quantum dot can be CdSe / ZnS, which emits green light or red light through size control.

[0092] 10. A display device is also provided in this embodiment of the present utility model, including a carrier device and an LED encapsulation structure as described above disposed on the carrier device, which has the same beneficial effects as the LED encapsulation structure, and will not be described again here.

[0093] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An LED packaging structure, characterized in that: The LED package includes a wiring layer, an LED chip electrically connected to the wiring layer, a fill layer surrounding the LED chip, and a sapphire layer disposed on the side of the LED chip away from the wiring layer and attached to the LED chip. The LED package structure also includes a phosphor layer surrounding the fill layer and the sapphire layer.

2. The LED packaging structure as described in claim 1, characterized in that: The side of the sapphire layer facing away from the LED chip is the light-emitting surface, and the projected area of ​​the light-emitting surface based on the wiring layer is larger than the projected area of ​​the LED chip based on the wiring layer.

3. The LED packaging structure as described in claim 2, characterized in that: The wiring layer includes solder joints located on the side away from the LED chip.

4. The LED packaging structure as described in claim 3, characterized in that: The fluorescent layer includes a top surface adjacent to the light-emitting surface and four side surfaces adjacent to the top surface. The side surfaces are directly bonded to the filling layer, the wiring layer, the solder joints, and the sapphire layer.

5. The LED packaging structure as described in claim 1, characterized in that: The LED packaging structure also includes a bonding layer disposed on the side of the LED chip near the sapphire layer.

6. The LED packaging structure as described in claim 5, characterized in that: The distance between the upper surface of the bonding layer and the wiring layer is greater than or equal to the distance between the LED chip and the wiring layer.

7. The LED packaging structure as described in claim 1, characterized in that: The thickness of the sapphire layer ranges from 20um to 400um.

8. The LED packaging structure as described in claim 1, characterized in that: The planar projected area of ​​the fluorescent layer relative to the wiring layer is greater than the planar projected area of ​​the sapphire layer relative to the wiring layer.

9. The LED packaging structure as described in claim 1, characterized in that: The fluorescent layer includes fluorescent materials or quantum dot materials, and the LED chip is a blue LED chip.

10. A display device, characterized in that: It includes a carrier device and an LED encapsulation structure as described in any one of claims 1-9 disposed on the carrier device.

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