An LED packaging structure and backlight panel

Abstract

This utility model relates to the field of display device technology, and in particular to an LED packaging structure and a backlight panel. The LED packaging structure includes 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 bonded to the LED chip. The sapphire includes a semiconductor thin film disposed on the side facing the wiring layer. The LED packaging structure also includes a photoluminescent layer disposed within the semiconductor thin film. A bonding layer is disposed between the semiconductor thin film and the LED chip and is bonded to the LED chip. When the photoluminescent layer is excited by blue light, it can emit light of the corresponding wavelength band, converting the blue light into white light or other single-color light, thus widening the color gamut range of the MIP product and making the light emission of the LED packaging structure more uniform.

Description

Technical Field

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

[0002] MIP, or "MicroLED in Package," is a packaging technology based on Mini LED or Micro LED. It cuts the Micro LED chip into individual small packages, splits and mixes the light in the small packages, and then performs a surface mount process to create a backlight panel.

[0003] Currently, MicroLED MIP products only have a single-color solution. The single-color solution uses a flip-chip structure bonded to the driver wiring layer. However, the fabrication process of MicroLED flip-chip is complex and the assembly efficiency is low. The single-color solution assembles three different blue, green and red MicroLEDs onto the same driver wiring layer, and mixes them to form independent full-color light. It requires the fabrication of three colors of MicroLED chips: blue, green and red. The fabrication process is relatively complex. Therefore, more solutions for color conversion in MIP products are needed. Utility Model Content

[0004] To address the problem of complex manufacturing processes in existing MIP products, this utility model provides an LED packaging structure and backlight panel.

[0005] The present invention provides an LED packaging structure to solve the technical problem, 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 bonded to the LED chip. The sapphire includes a semiconductor thin film disposed on the side facing the wiring layer. The LED packaging structure also includes a photoluminescent layer disposed within the semiconductor thin film. A bonding layer is provided between the semiconductor thin film and the LED chip, and the bonding layer is bonded to the LED chip.

[0006] Preferably, the photoluminescent layer is a multi-quantum well formed by stacking several alternately arranged potential well layers and potential barrier layers.

[0007] Preferably, the thickness of the potential well layer is between 2 nm and 5 nm, and the thickness of the potential barrier layer is between 5 nm and 15 nm.

[0008] Preferably, the potential well layer is a potential well layer containing indium.

[0009] Preferably, the LED packaging structure includes one or more photoluminescent layers, with adjacent photoluminescent layers spaced apart in the semiconductor thin film.

[0010] Preferably, the thickness of the photoluminescent layer is less than or equal to 200 nm.

[0011] Preferably, the thickness of the sapphire layer is between 100um and 200um.

[0012] Preferably, a phosphor layer is provided on the side of the bonding layer closest to the LED chip.

[0013] Preferably, the wiring layer includes solder joints disposed on the side away from the LED chip.

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

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

[0016] 1. The LED packaging structure provided in this embodiment of the present invention includes a wiring layer that enables the transmission of electrical signals and current of the LED chip, a filling layer that surrounds the LED chip and fills the surrounding environment flush with the LED chip to provide protection for the LED chip, the LED chip being the light source of the LED packaging structure, a photoluminescent layer receiving the initial light from the LED chip and generating mixed light through wavelength conversion to meet the specific spectral requirements of the LED packaging structure, and a sapphire layer serving as a light-transmitting carrier that protects the internal semiconductor film and photoluminescent layer while also conducting light to the outside; the semiconductor film is an n-type GaN epitaxial film, and the photoluminescent layer is disposed within the n-type GaN epitaxial film, which provides structural support for the photoluminescent layer; and a bonding layer that ensures tight adhesion between the LED chip and the semiconductor film, reducing light loss and structural loosening.

[0017] 2. The LED packaging structure provided in this embodiment of the present invention has a photoluminescent layer consisting of multiple quantum wells formed by stacking several alternating potential well layers and potential barrier layers. The potential well layers are made of InGaN-based materials, i.e., indium gallium nitride, and the potential barrier layers are made of wide bandgap materials such as GaN or AlGaN, i.e., gallium nitride or aluminum gallium nitride. The bandgap of the potential barrier layer is larger than that of the potential well layer, which confines electrons and holes within the potential well layer and reduces their recombination loss in the non-light-emitting region, thereby improving the quantum efficiency of photoluminescence. The alternating stacking of multiple layers can increase the recombination opportunities of electron-hole pairs, further improving the overall luminous intensity.

[0018] 3. In the LED packaging structure provided in this embodiment, the potential well layer is the core region for electron-hole recombination and light emission. The thickness affects the quantum confinement effect and the recombination efficiency of charge carriers. When the thickness of the potential well layer is between 2 and 5 nm, the quantum size effect is significant, the energy state exhibits a quantized distribution, and the recombination probability of charge carriers is greatly increased, thereby improving the photoluminescence efficiency. The barrier layer prevents charge carriers from escaping. The thickness needs to balance the confinement ability and the stability of crystal growth. When the thickness of the barrier layer is between 5 and 15 nm, it effectively confines the charge carriers and prevents electrons and holes in the potential well layer from diffusing to adjacent potential well layers or external regions.

[0019] 4. The LED packaging structure provided in this embodiment of the present invention has an InGaN material as the potential well layer, which contains indium. By setting different concentrations of indium (In), the band gap and emission wavelength of the potential well layer can be controlled, thereby optimizing the performance of the photoluminescent layer: the higher the In concentration, the smaller the band gap of InGaN, and the longer the corresponding emission wavelength, shifting from ultraviolet to visible light, and even near-infrared; the lower the In concentration, the larger the band gap, and the shorter the emission wavelength. By setting different In concentrations in the potential well layer, multiple quantum wells emit light of different wavelengths, which are superimposed to form the emitted light of the target color.

[0020] 5. The LED packaging structure provided in this embodiment of the present invention has one or more photoluminescent layers, and adjacent photoluminescent layers are spaced apart in the semiconductor thin film. The spaced distribution allows the emitted light of each photoluminescent layer to be superimposed in space, forming a broad spectrum that is closer to white light or other single-color light, which meets the requirements of the LED packaging structure for the color gamut of light. The spaced arrangement avoids spectral interference from direct contact between different photoluminescent layers, reduces energy transfer loss, ensures that the light emission characteristics of each layer are independent and controllable, improves photoluminescence efficiency, and reduces energy loss.

[0021] 6. In the LED packaging structure provided in this embodiment of the present invention, the photoluminescent layer is prepared by epitaxial growth. During the crystal growth process, defects such as dislocations or vacancies will be generated. These defects will accumulate as the thickness increases. By limiting the thickness of the photoluminescent layer to within 200 nm, the longitudinal extension of defects is reduced, making it easier for charge carriers to recombine and emit light in the defect-free region, thereby maintaining a high internal quantum efficiency, preventing charge carrier escape, and enhancing the trapping ability of the potential well layer.

[0022] 7. In the LED packaging structure provided in this 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 100–200 μm 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. The LED packaging structure provided in this embodiment of the present invention has a bonding layer that connects the LED chip and the sapphire, fixes the LED chip and transmits light. A phosphor layer is provided on the side of the bonding layer near the LED chip. The phosphor layer contains one or more phosphors such as fluoride system, aluminate system, phosphate system, orthosilicate system, borate system, and oxide-based system, which can absorb blue light and emit red light. The phosphors can be mixed with the green light emitted by the photoluminescent layer to form white light, or they can be mixed to form other single-color light, thereby improving light uniformity and reducing color deviation.

[0024] 9. 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.

[0025] 10. A backlight panel is also provided in this embodiment of the present invention, 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 this utility model.

[0028] Figure 2 This is a schematic diagram of the process of epitaxially growing a photoluminescent layer on the sapphire layer of the LED packaging structure provided in the first embodiment of this utility model.

[0029] Figure 3This is a side view of the LED packaging structure provided in the second embodiment of this utility model.

[0030] Figure 4 This is a top view of the backlight panel provided in the third embodiment of the present invention. Figure 1 .

[0031] Figure 5 This is a top view of the backlight panel provided in the third embodiment of the present invention. Figure 2 .

[0032] Explanation of reference numerals in the attached diagram:

[0033] 100, LED packaging structure; 200, LED packaging structure; 300, backlight panel; 301, carrier device;

[0034] 1. LED chip; 2. Wiring layer; 3. Filler layer; 4. Sapphire layer; 5. Bonding layer; 6. Semiconductor thin film.

[0035] 21. Solder joint; 51. Fluorescent layer; 61. Photoluminescent layer; 62. Buffer layer; 63. Electron transport layer; 611. Potential well layer; 612. Potential barrier layer. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Please see Figure 1 The 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 2 and bonded to the LED chip 1. The sapphire includes a semiconductor thin film 6 disposed on the side facing the wiring layer 2. The LED packaging structure 100 also includes a photoluminescent layer 61 disposed in the semiconductor thin film 6. A bonding layer 5 is provided between the semiconductor thin film 6 and the LED chip 1, and the bonding layer 5 is bonded to the LED chip 1.

[0042] Understandably, LED chip 1 serves as the excitation light source, emitting blue light. Blue LEDs have high luminous efficiency and long lifespan, and blue light is an ideal energy source for exciting the photoluminescent layer 61 to generate light of other wavelengths. Wiring layer 2 provides electrical connection for LED chip 1, enabling current input to drive LED light emission. Integrated wiring reduces external line interference and improves the compactness and stability of LED package structure 100. Filling layer 3 is set around LED chip 1, fixing the position of LED chip 1 and reducing light leakage during propagation on the side of LED chip 1, improving the structural mechanical strength of LED package structure 100, preventing LED chip 1 from falling off due to vibration or temperature changes, reducing light loss to improve light utilization. Sapphire layer 4 serves as a carrier and light-transmitting substrate, supporting semiconductor thin film 6 and photoluminescent layer 61. It has high light transmittance and strong chemical stability, protecting the internal structure of LED package structure 100.

[0043] Specifically, the function of the photoluminescent layer 61 is to emit light. When the photoluminescent layer 61 is irradiated by excitation light of a specific wavelength, the photoluminescent layer 61 absorbs light energy and releases the energy in the form of visible light through an electron transition process, thereby achieving the effect of emitting light.

[0044] Further, please refer to Figure 2 Semiconductor thin film 6 uses gallium nitride (GaN) based material.

[0045] In one non-limiting embodiment, sapphire (Al2O3) is chosen as the substrate of the semiconductor thin film 6 because its crystal structure has a high degree of matching with that of the GaN material, good chemical stability, and strong light transmittance. In specific scenarios, substrates such as SiC and Si can also be used to meet more light emission requirements. In this embodiment, no specific limitation is made, as long as it can serve as a substrate and provide physical support.

[0046] It should be noted that the semiconductor thin film 6 in this embodiment uses GaN-based material, which is a gallium nitride semiconductor thin film 6 doped with conductive impurities (such as silicon). In more embodiments, gallium nitride without conductive impurities can also be used as the base material of the semiconductor thin film 6, as long as it can meet the growth requirements of the photoluminescent layer 61. This embodiment does not limit the specific material of the semiconductor thin film 6.

[0047] Furthermore, the semiconductor thin film 6 includes a buffer layer 62.

[0048] Understandably, since the lattice constant and thermal expansion coefficient of the sapphire layer 4 substrate and the GaN semiconductor thin film 6 are quite different, directly growing the GaN semiconductor thin film 6 is prone to generating a large number of dislocations and defects. Therefore, it is necessary to grow the buffer layer 62 first.

[0049] Specifically, please refer to Figure 2 In this invention, the buffer layer 62 is made of aluminum nitride (AlN) material as a buffer transition layer to alleviate the lattice mismatch between sapphire and GaN semiconductor thin film 6 and reduce the dislocation density of subsequent semiconductor thin film 6.

[0050] Furthermore, the semiconductor thin film 6 includes an electron transport layer 63.

[0051] Understandably, in LED chip 1, the efficient transport and recombination of electrons and holes is the key to light emission. In this embodiment, the electron transport layer 63 is made of n-type gallium nitride (n-GaN) material.

[0052] Specifically, when the LED chip 1 is working and a forward bias voltage is applied, electrons are injected from the n-GaN electron transport layer 63 into the photoluminescent layer 61.

[0053] Furthermore, the photoluminescent layer 61 is a multi-quantum well formed by stacking several alternately arranged potential well layers 611 and potential barrier layers 612.

[0054] Understandably, the semiconductor thin film 6 is the carrier of the photoluminescent layer 61, which is the key to realizing white light and other single-color light. The photoluminescent layer 61 changes the wavelength emitted after being excited by blue light by changing the bandgap width: the wavelength of photoluminescence is determined by the bandgap width of the material. When the bandgap width decreases, the corresponding emission wavelength will become longer due to the decrease in energy. The emission wavelength can shift from green light (narrow bandgap) to red light (even narrower bandgap). In combination with the blue light excitation source, full-spectrum white light is realized. That is, the blue light of the blue LED chip 1 itself is mixed with the red and green light emitted by the photoluminescent layer 61 to finally synthesize white light, which meets the needs of the LED packaging structure 100 for white light source or other single-color light.

[0055] Specifically, the potential well layer 611 and the barrier layer 612 are stacked alternately to enhance the quantum confinement effect and improve the luminescence efficiency. The potential well layer 611 is the luminescent region, and its material is InGaN. InGaN has a narrow band gap, and electrons and holes are easy to recombine and emit light here. The barrier layer 612 is made of GaN. GaN has a wide band gap, which confines electrons and holes within the potential well layer 611 and reduces their overflow loss. The alternating stacking of the potential well layer 611 and the barrier layer 612 increases the probability of electron and hole recombination, which significantly improves the luminescence efficiency compared to the single-layer structure.

[0056] Furthermore, the thickness of the potential well layer 611 ranges from 2 nm to 5 nm, and the thickness of the barrier layer 612 ranges from 5 nm to 15 nm.

[0057] Understandably, the thickness of the potential well layer 611 is in the nanometer range, confined within 2nm–5nm. The space for electron movement is strictly limited. The thinner the potential well layer 611, the larger the energy level spacing and the shorter the emitted light wavelength. The thickness of the barrier layer 612 is confined within 5nm–15nm, balancing carrier confinement and interlayer coupling. It effectively confines carrier recombination within the potential well layer 611, ensuring uniform light emission from each potential well layer 611. If the barrier layer 612 is too thin, it cannot effectively block the overflow of electrons or holes, weakening the quantum confinement effect and reducing the luminous efficiency. If the barrier layer 612 is too thick, it will hinder the distribution of carriers among the potential well layers 611, causing some potential well layers 611 to emit weak light due to insufficient carriers, resulting in a decrease in overall light intensity.

[0058] Furthermore, the potential well layer 611 is a potential well layer 611 containing indium.

[0059] Specifically, in the InGaN well layer 611, the higher the indium concentration, the smaller the band gap of the material, and the lower the indium concentration, the larger the band gap of the material. High indium concentration corresponds to red light, and low indium concentration corresponds to green light.

[0060] It should be noted that, in terms of crystal structure, different indium doping concentrations represent the occupancy of Ga elements in GaN crystals by In, i.e., In(x)Ga(1-x)N, which is the proportion of Ga elements replaced by In.

[0061] Furthermore, due to the change in the indium doping concentration, the width of the corresponding potential well layer 611 also needs to be adapted accordingly.

[0062] Understandably, the different doping concentrations of indium in the potential well layer 611 allow for continuous wavelength modulation from green to red without changing the material system, simply by adjusting the indium concentration. Combined with the primary color of the blue LED chip 1, it can cover the full spectrum required for white light or other single-color light, and its luminous stability is far higher than that of traditional phosphor color-changing structures.

[0063] Furthermore, the LED packaging structure 100 includes one or more photoluminescent layers 61, with adjacent photoluminescent layers 61 spaced apart in the semiconductor thin film 6.

[0064] Understandably, the multilayer photoluminescent layers 61 work together to extend the spectral range, improve light output efficiency, and optimize white light quality. The adjacent photoluminescent layers 61 are spaced apart in the semiconductor thin film 6 to avoid mutual interference between the charge carriers and light in the adjacent layers, ensuring that each photoluminescent layer 61 can emit light stably at the designed wavelength, and preventing the long-wavelength light emitted by a certain layer from being reabsorbed by the adjacent short-wavelength light-emitting layer, thereby reducing light loss and alleviating stress accumulation in the multilayer stack.

[0065] Furthermore, the different photoluminescent layers 61 are separated by an n-type GaN layer, i.e., an electron transport layer 63.

[0066] Specifically, when the multilayer photoluminescent layers 61 are stacked, the existing n-type GaN layer, i.e., the electron transport layer 63, is used as a natural spacer layer. This saves on the process, eliminating the need for additional isolation layer deposition, and utilizes its semiconductor properties to control the optical properties between the multilayer photoluminescent layers 61. For example... Figure 2 The schematic diagram showing the process of epitaxially growing photoluminescent layer 61 on sapphire layer 4 illustrates two sets of photoluminescent layers 61.

[0067] Furthermore, the thickness of the photoluminescent layer 61 is less than or equal to 200 nm.

[0068] Specifically, the thickness of the photoluminescent layer 61 is controlled to be within 200 nm to balance the quantum confinement effect, light absorption efficiency and structural stability, and to avoid light absorption saturation and efficiency reduction caused by excessive thickness. At the same time, the thickness of the photoluminescent layer 61 is less than or equal to 200 nm to adapt to the fabrication process of the semiconductor thin film 6 and improve structural stability: the photoluminescent layer 61 is prepared by epitaxial growth. An excessively thick photoluminescent layer 61 will cause the thin film to crack or have dense defects due to lattice mismatch and thermal stress.

[0069] In one feasible embodiment, the semiconductor thin film 6 of the LED chip 1 is prepared by epitaxial growth technology, and the specific preparation process is as follows: Figure 2 As shown: Using sapphire layer 4 as a substrate, GaN epitaxial layers, i.e., semiconductor thin film 6, are grown layer by layer on the surface of the sapphire substrate. The growth of semiconductor thin film 6 includes: first, growing an aluminum nitride (AlN) buffer layer 62, then sequentially growing an n-type gallium nitride (n-GaN) electron transport layer 63, a photoluminescent layer 61, and finally growing another n-type gallium nitride (n-GaN) electron transport layer 63 on the aluminum nitride (AlN) buffer layer 62. The growth direction is as follows. Figure 2 As indicated by the middle arrow.

[0070] After epitaxy is completed, the sapphire substrate is left unpeeled. At this time, the sapphire layer 4 serves as both the substrate for the growth of the LED chip 1 and a physical support, protecting it from mechanical damage. At the same time, due to its high light transmittance, it can serve as an optical window for the LED chip 1, allowing light to escape from one side of the sapphire substrate.

[0071] Furthermore, the thickness of the sapphire layer 4 ranges from 100um to 200um.

[0072] Understandably, the sapphire layer 4 has high hardness and mechanical strength, which can provide a stable physical support framework for the entire LED packaging structure 100. The sapphire layer 4 with a thickness of 100um-200um ensures the uniformity of optical performance, so that the light emitted from different positions of the LED chip 1 has consistent optical transmission characteristics when passing through the sapphire layer 4, which helps to improve the uniformity of light emission and avoid uneven light spots.

[0073] Furthermore, the wiring layer 2 includes solder joints 21 disposed on the side away from the LED chip 1.

[0074] Understandably, solder joint 21 provides a direct and reliable electrical connection point between LED chip 1 and external circuit. In subsequent packaging and application stages, LED chip 1 can be connected to external circuit through soldering processes, such as tin soldering, to achieve power input, enabling LED chip 1 to work normally and convert electrical energy into light energy.

[0075] Further, see Figure 3 The second embodiment of this utility model provides an LED packaging structure 200. The only difference between the LED packaging structure 200 of the second embodiment and the LED packaging structure 100 provided in the first embodiment is that the bonding layer 5 of the LED packaging structure 200 is provided with a phosphor layer 51 on the side close to the LED chip 1.

[0076] In one non-limiting embodiment, the photoluminescent layer 61 of the LED packaging structure 100 provided in the first embodiment, after being excited by blue light, mainly emits green light in the potential well layer 611 and the barrier layer 612 with indium elements set.

[0077] Based on the principle of three primary colors, the second embodiment provides an LED packaging structure 200 in which the bonding layer 5 includes a phosphor layer 51. The LED packaging structure 200 uses a blue LED chip 1. During the packaging process, one or more phosphors such as fluoride system, aluminate system, phosphate system, orthosilicate system, borate system, and oxide-based system are added to the phosphor layer 51. These phosphors can absorb blue light and emit red light. The red light is mixed with the green light emitted by the photoluminescent layer 61 to form white light, or other single-color light. The phosphor layer 51 used in the LED packaging structure 200 is directly integrated on the side of the bonding layer 5 close to the LED chip 1. The bonding layer 5 directly realizes color conversion while bonding the sapphire layer 4 and the LED chip 1. The bonding layer 5 and the phosphor layer 51 are treated as a whole layer, and a special bonding layer 5 is formed by adding color conversion material.

[0078] Specifically, the photoluminescent layer 61 absorbs the blue light emitted by the LED chip 1 and converts the energy into light of another wavelength through energy level transitions within the material. The mixing of different wavelengths of light achieves color change. Meanwhile, the phosphor particles in the fluorescent layer 51 absorb the blue light emitted by the LED chip 1. After being excited, the electrons transition to a higher energy level and release fluorescence of different wavelengths, such as red and green light, when they fall back. This fluorescence mixes with the unabsorbed excitation light to form the target color light.

[0079] Understandably, the bonding layer 5 of the LED package structure 200 has a phosphor layer 51 on the side close to the LED chip 1, and phosphor is disposed in the phosphor layer 51. The LED package structure 100 uses a photoluminescent layer 61 to achieve color conversion. The LED package structure 200 uses different materials and structures to achieve color conversion compared to the LED package structure 100. As two differentiated color conversion technologies, the photoluminescent layer 61 improves the color temperature and brightness uniformity of the light, while the phosphor layer 51 has more precise local color conversion capability and structural compatibility, providing a variety of solutions for the performance optimization of the LED package structure 200 provided by this utility model.

[0080] Furthermore, quantum dots are a type of nanoscale semiconductor material with unique photoelectric properties. The color of their emission can be controlled by changing parameters such as size. The LED packaging structure 200 can also introduce quantum dots into the bonding layer 5. Blue light excites the quantum dots to emit light of a specific color, which mixes with the directly emitted blue light to form white light or other single-color light.

[0081] See Figure 4 and Figure 5The third embodiment of this utility model provides a backlight panel 300, including a carrier device 301 and an LED encapsulation structure 100 as in the first embodiment or an LED encapsulation structure 200 as in the second embodiment disposed on the carrier device 301.

[0082] The backlight panel 300 has the same beneficial effects as the LED package structure 100 in the first embodiment or the LED package structure 200 in the second embodiment, which will not be described in detail here.

[0083] Optionally, the backlight panel 300 may include various lamps on vehicle and transportation equipment, as well as general lighting equipment, display and backlight equipment, and consumer electronics and home appliances, depending on the application scenario and function. Specifically, the arrangement method and number of LED packaging structures on the carrier device 301 are not limited according to different application scenarios.

[0084] Compared with the prior art, the LED packaging structure and backlight panel provided by this utility model have the following advantages:

[0085] 1. The LED packaging structure provided in this embodiment of the present invention includes a wiring layer that enables the transmission of electrical signals and current of the LED chip, a filling layer that surrounds the LED chip and fills the surrounding environment flush with the LED chip to provide protection for the LED chip, the LED chip being the light source of the LED packaging structure, a photoluminescent layer receiving the initial light from the LED chip and generating mixed light through wavelength conversion to meet the specific spectral requirements of the LED packaging structure, and a sapphire layer serving as a light-transmitting carrier that protects the internal semiconductor film and photoluminescent layer while also conducting light to the outside; the semiconductor film is an n-type GaN epitaxial film, and the photoluminescent layer is disposed within the n-type GaN epitaxial film, which provides structural support for the photoluminescent layer; and a bonding layer that ensures tight adhesion between the LED chip and the semiconductor film, reducing light loss and structural loosening.

[0086] 2. The LED packaging structure provided in this embodiment of the present invention has a photoluminescent layer consisting of multiple quantum wells formed by stacking several alternating potential well layers and potential barrier layers. The potential well layers are made of InGaN-based materials, i.e., indium gallium nitride, and the potential barrier layers are made of wide bandgap materials such as GaN or AlGaN, i.e., gallium nitride or aluminum gallium nitride. The bandgap of the potential barrier layer is larger than that of the potential well layer, which confines electrons and holes within the potential well layer and reduces their recombination loss in the non-light-emitting region, thereby improving the quantum efficiency of photoluminescence. The alternating stacking of multiple layers can increase the recombination opportunities of electron-hole pairs, further improving the overall luminous intensity.

[0087] 3. In the LED packaging structure provided in this embodiment, the potential well layer is the core region for electron-hole recombination and light emission. The thickness affects the quantum confinement effect and the recombination efficiency of charge carriers. When the thickness of the potential well layer is between 2 and 5 nm, the quantum size effect is significant, the energy state exhibits a quantized distribution, and the recombination probability of charge carriers is greatly increased, thereby improving the photoluminescence efficiency. The barrier layer prevents charge carriers from escaping. The thickness needs to balance the confinement ability and the stability of crystal growth. When the thickness of the barrier layer is between 5 and 15 nm, it effectively confines the charge carriers and prevents electrons and holes in the potential well layer from diffusing to adjacent potential well layers or external regions.

[0088] 4. The LED packaging structure provided in this embodiment of the present invention has an InGaN material as the potential well layer, which contains indium. By setting different concentrations of indium (In), the band gap and emission wavelength of the potential well layer can be controlled, thereby optimizing the performance of the photoluminescent layer: the higher the In concentration, the smaller the band gap of InGaN, and the longer the corresponding emission wavelength, shifting from ultraviolet to visible light, and even near-infrared; the lower the In concentration, the larger the band gap, and the shorter the emission wavelength. By setting different In concentrations in the potential well layer, multiple quantum wells emit light of different wavelengths, which are superimposed to form the emitted light of the target color.

[0089] 5. The LED packaging structure provided in this embodiment of the present invention has one or more photoluminescent layers, and adjacent photoluminescent layers are spaced apart in the semiconductor thin film. The spaced distribution allows the emitted light of each photoluminescent layer to be superimposed in space, forming a broad spectrum that is closer to white light or other single-color light, which meets the requirements of the LED packaging structure for the color gamut of light. The spaced arrangement avoids spectral interference from direct contact between different photoluminescent layers, reduces energy transfer loss, ensures that the light emission characteristics of each layer are independent and controllable, improves photoluminescence efficiency, and reduces energy loss.

[0090] 6. In the LED packaging structure provided in this embodiment of the present invention, the photoluminescent layer is prepared by epitaxial growth. During the crystal growth process, defects such as dislocations or vacancies will be generated. These defects will accumulate as the thickness increases. By limiting the thickness of the photoluminescent layer to within 200 nm, the longitudinal extension of defects is reduced, making it easier for charge carriers to recombine and emit light in the defect-free region, thereby maintaining a high internal quantum efficiency, preventing charge carrier escape, and enhancing the trapping ability of the potential well layer.

[0091] 7. In the LED packaging structure provided in this 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 100–200 μm 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.

[0092] 8. The LED packaging structure provided in this embodiment of the present invention has a bonding layer that connects the LED chip and the sapphire, fixes the LED chip and transmits light. A phosphor layer is provided on the side of the bonding layer near the LED chip. The phosphor layer contains one or more phosphors such as fluoride system, aluminate system, phosphate system, orthosilicate system, borate system, and oxide-based system, which can absorb blue light and emit red light. The phosphors can be mixed with the green light emitted by the photoluminescent layer to form white light, or they can be mixed to form other single-color light, thereby improving light uniformity and reducing color deviation.

[0093] 9. 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.

[0094] 10. An embodiment of this utility model also provides a backlight panel, 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 repeated here. The above descriptions are merely preferred embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, and improvements made within the principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An LED packaging structure, characterized in that: The package includes a wiring layer, an LED chip electrically connected to the wiring layer, a filler layer surrounding the LED chip, and a sapphire layer disposed on the side of the LED chip away from the wiring layer and bonded to the LED chip. The sapphire includes a semiconductor thin film disposed on the side facing the wiring layer. The LED packaging structure also includes a photoluminescent layer disposed within the semiconductor thin film. A bonding layer is provided between the semiconductor thin film and the LED chip, and the bonding layer is bonded to the LED chip.

2. The LED packaging structure as described in claim 1, characterized in that: The photoluminescent layer is a multi-quantum well composed of several alternately arranged potential well layers and potential barrier layers stacked together.

3. The LED packaging structure as described in claim 2, characterized in that: The thickness of the potential well layer ranges from 2 nm to 5 nm, and the thickness of the potential barrier layer ranges from 5 nm to 15 nm.

4. The LED packaging structure as described in claim 2, characterized in that: The potential well layer is a potential well layer containing indium.

5. The LED packaging structure as described in claim 1, characterized in that: The LED packaging structure includes one or more photoluminescent layers, with adjacent photoluminescent layers spaced apart in the semiconductor thin film.

6. The LED packaging structure as described in claim 1, characterized in that: The thickness of the photoluminescent layer is less than or equal to 200 nm.

7. The LED packaging structure as described in claim 1, characterized in that: The thickness of the sapphire layer ranges from 100um to 200um.

8. The LED packaging structure as described in claim 1, characterized in that: A phosphor layer is provided on the side of the bonding layer closest to the LED chip.

9. The LED packaging structure as described in claim 1, characterized in that: The wiring layer includes solder joints located on the side away from the LED chip.

10. A backlight panel, 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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