High-color gamut LED packaging structure and production method therefor

Abstract

A high-color gamut LED packaging structure and a production method therefor. The structure comprises a support, the support being used for providing physical support and electrical connection for elements mounted on a support. An LED chip is mounted on a top surface of the support, and a packaging mechanism is sleeved on the exterior of the LED chip. The packaging mechanism comprises packaging glue, a fluorescent powder being mixed in the packaging glue, and the color of the fluorescent powder being red. The LED chip comprises multi-quantum well layers, and the multi-quantum well layers are used for generating light having different wavelengths. Blue light and green light multi-quantum well layers are integrated in the LED chip, and in combination with with the external red fluorescent powder, when LED lamp beads are electrified to emit light, due to a spectrum composed of blue light of the chip, green light of the chip and red fluorescent powder, the NTSC color gamut is higher than that of blue light excited fluorescent powder, multiple colors of light are directly generated on a single chip, dependence on a pure chip scheme is reduced, and fewer chips are used than in a pure chip scheme, thereby reducing costs.

Description

A high color gamut LED packaging structure and its manufacturing method Technical Field

[0001] This invention relates to the field of LED technology, and in particular to a high color gamut LED packaging structure and its manufacturing method. Background Technology

[0002] An LED (Light Emitting Diode) is a solid-state semiconductor device that converts electrical energy into light energy. It boasts advantages such as low power consumption, excellent light focusing effect, fast response speed, strong controllability, ability to withstand high impacts, long lifespan, and environmental friendliness. LEDs are gradually replacing traditional light sources, becoming the fourth generation of light sources. For LED packaging devices, different packaging structures have a significant impact on LEDs, affecting aspects such as lifespan, emission angle, and color gamut.

[0003] To achieve high color gamut LEDs, many solutions use a combination of chips and high color gamut phosphors. If a blue chip is used with phosphors, the NTSC color gamut can only be achieved at a maximum of about 95%, and the lifespan is also relatively short. If a pure chip approach is used, the cost of the LEDs would be very high.

[0004] The purpose of this invention is to solve the problems of low color gamut and high price of traditional LED lamp beads. Technical issues

[0005] The purpose of this invention is to solve the problems of low color gamut and high price of traditional LED chips. The invention adopts the following technical solution:

[0006] A high color gamut LED packaging structure and its manufacturing method are disclosed, including a bracket, which provides physical support and electrical connection for components mounted on the bracket. An LED chip is mounted on the top surface of the bracket, and an encapsulation mechanism is provided around the LED chip. The encapsulation mechanism includes encapsulating adhesive, and phosphor is mixed in the encapsulating adhesive. The phosphor is red in color.

[0007] The LED chip includes a multi-quantum well layer, which is used to generate light of different wavelengths. The multi-quantum well layer includes several blue light multi-quantum well layers and several green light multi-quantum well layers.

[0008] The high color gamut LED packaging structure and its manufacturing method described above, wherein both the blue and green multi-quantum well layers are composed of an InGaN (indium gallium nitride) barrier layer and an InGaN well layer, the InGaN barrier layer of the green multi-quantum well layer has a thickness of 5-25 nm, an In content of 20%-85%, and an emission wavelength of 515-550 nm, the InGaN well layer of the green multi-quantum well layer has a thickness of 1-7 nm, and an In content of 1%-25%, the InGaN barrier layer of the blue multi-quantum well layer has a thickness of 5-25 nm, an In content of 10%-40%, and an emission wavelength of 440-470 nm, the InGaN well layer of the blue multi-quantum well layer has a thickness of 1-7 nm, and an In content of 1%-25%.

[0009] In the high color gamut LED packaging structure and its manufacturing method described above, a P-type GaN layer (hole-type gallium nitride layer) is disposed above the multi-quantum well layer, and an N-type GaN layer (electron-type gallium nitride layer) is disposed below the multi-quantum well layer. The N-type GaN layer provides electrons, and the P-type GaN layer provides holes. The P-type GaN layer and the N-type GaN layer together form a PN junction.

[0010] In the high color gamut LED packaging structure and its manufacturing method described above, an undoped GaN layer is disposed below the N-type GaN layer, the LED chip includes a substrate, and a GaN buffer layer is disposed between the undoped GaN layer and the substrate.

[0011] The high color gamut LED packaging structure and its manufacturing method as described above, wherein the packaging mechanism includes a support cup, the support cup is made of a transparent or opaque material, the support cup is fixedly connected to a support, and the support cup is sleeved on the outside of the encapsulating adhesive.

[0012] In the high color gamut LED packaging structure and its manufacturing method described above, bonding wires are soldered to both the positive and negative electrodes of the LED chip. One end of the bonding wire is fixedly connected to a bracket, and the bracket is electrically connected to the LED chip through the bonding wire.

[0013] In the high color gamut LED packaging structure and its manufacturing method described above, the side of the LED chip that contacts the bracket 1 is coated with die bond adhesive, and the LED chip is fixedly connected to the bracket through the die bond adhesive.

[0014] The high color gamut LED packaging structure and its manufacturing method described above involve alternating stacking of several blue multi-quantum well layers and several green multi-quantum well layers. Technical solutions

[0015] A manufacturing process for a high color gamut LED packaging structure includes the following steps:

[0016] Step 1: Growing an epitaxial layer. An epitaxial layer is grown for LED chip 5 using metal compound vapor deposition.

[0017] Step 2: Fabricate LED chips, including electrodes, current spreading layer, current blocking layer, protective layer, reflective layer, etc., and finally cut them into individual LED chips.

[0018] Step 3: Die bonding, fixing the LED chip onto the bracket;

[0019] Step 4: Wire bonding, which uses bonding wires to form an electrical connection between the substrate and the chip;

[0020] Step 5: Apply fluorescent adhesive by dispensing or spraying. Preferably, the fluorescent powder in the fluorescent adhesive is a red fluoride fluorescent powder.

[0021] Step Six: Test the packaging.

[0022] A method for producing a high color gamut LED packaging structure, characterized in that step one further includes the following steps:

[0023] Adjusting the reaction chamber temperature to the range of 650-950℃ lays the foundation for high-quality growth of InGaN materials. When growing green quantum well layers, the thickness of the green quantum well barrier layer is set to 5 to 25 nm, the In content is set to 20%-85%, the well layer thickness is set to 1-7 nm, and the target wavelength is locked in the range of 515 to 550 nm. When growing blue quantum well layers, the thickness of the blue quantum well barrier layer is set to 5 to 25 nm, the In content is set to 10%-40%, the well layer thickness is set to 1-7 nm, and the target wavelength is locked in the range of 440 to 470 nm. Beneficial effects

[0024] Implementing the embodiments of the present invention has the following beneficial effects:

[0025] 1. In this invention, by integrating blue and green multiple quantum well layers in an LED chip and combining them with external red phosphor, when the LED bead is powered on, the spectrum composed of the blue light from the chip, the green light from the chip, and the red phosphor has a higher NTSC color gamut than the color gamut of the phosphor excited by blue light. By directly generating multiple colors of light on a single chip, the dependence on pure chip solutions is reduced, and fewer chips are used compared to pure chip solutions, thereby reducing costs.

[0026] 2. In this invention, an undoped GaN layer and a GaN buffer layer are used, which effectively alleviates the lattice mismatch between different materials, reduces the dislocation density, and thus enhances the crystal quality and long-term reliability of the device.

[0027] In summary, this invention solves the problems of low color gamut and high price of traditional LED lamp beads. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 is a schematic diagram of the structure of a high color gamut LED packaging structure of the present invention when a standard chip is installed.

[0030] Figure 2 is a schematic diagram of the LED chip structure of the high color gamut LED packaging structure and its production method according to the present invention.

[0031] Figure 3 is a schematic diagram of the multi-quantum well layer structure of a high color gamut LED packaging structure and its manufacturing method according to the present invention.

[0032] Figure 4 is a schematic diagram of the structure of a high color gamut LED packaging structure of the present invention when a flip chip is installed. Embodiments of the present invention

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] As shown in Figures 1 to 4, this invention proposes a high color gamut LED packaging structure and its manufacturing method, including a bracket 1. The bracket 1 provides physical support and electrical connection for components mounted on it. An LED chip 5 is mounted on the top surface of the bracket 1. The LED chip 5 is of one type: a standard chip, a vertical chip, or a flip chip. An encapsulation mechanism is provided around the LED chip 5. The encapsulation mechanism includes an encapsulating adhesive 3. The encapsulating adhesive 3 is made of one of the following materials: PCT (polycyclohexane terephthalate) injection molding compound, PPA (polyphthalamide) injection molding compound, epoxy resin, and silicone. Phosphor powder 4 is mixed into the encapsulating adhesive 3.

[0035] The LED chip 5 includes a multi-quantum well layer 55, which is used to generate light of different wavelengths. The multi-quantum well layer 55 includes a plurality of blue light multi-quantum well layers 551 and a plurality of green light multi-quantum well layers 551.

[0036] LED chip 5 serves as the light-emitting element, containing a multi-quantum-well layer 55. The multi-quantum-well layer 55 is composed of multiple very thin semiconductor layers, capable of altering the recombination process of electrons and holes through quantum confinement effects, thereby controlling the energy of the released photons, i.e., the wavelength of light. Blue and green multi-quantum-well layers 551 are responsible for generating blue and green light, respectively. By controlling the structure and materials of these multi-quantum-wells, light in specific wavelength bands can be effectively generated, laying the foundation for high color gamut displays.

[0037] Phosphor powder and encapsulating adhesive are mixed together to form a fluorescent adhesive. The phosphor powder particles account for 0%-90% of the weight of the fluorescent adhesive. The encapsulating adhesive is one of silicone, epoxy resin, or modified epoxy silicone resin. The phosphor powder particles contain one or more phosphors, and the phosphor material can be one or more excitable materials such as nitrides, aluminates, silicates, nitrides, sulfides, and fluorides. The phosphor material is preferably a fluoride.

[0038] Optionally, in some embodiments, when the LED chip 51 is a conventional chip or a flip chip, the substrate 51 is made of sapphire. Sapphire substrates have extremely high chemical and thermal stability, making them suitable for the high-temperature environment during LED growth.

[0039] Optionally, in some embodiments, when the LED chip 51 is a vertical chip, the substrate 51 is made of silicon or silicon carbide. Silicon is the most commonly used material in the semiconductor industry, with high production volume and low cost. Silicon has better thermal conductivity than sapphire, which helps to improve the heat dissipation performance of the LED.

[0040] Optionally, in some embodiments, the substrate 51 is made of gallium nitride. The gallium nitride substrate has a high lattice matching degree with the gallium nitride epitaxial layer, which can grow a high-quality epitaxial film, greatly reducing the dislocation density and improving the device performance.

[0041] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the phosphor 4 is red. Through the conversion effect of the red phosphor, the LED light source can obtain red light components in addition to the directly emitted blue and green light, which significantly broadens the color gamut coverage of the light source. Specifically, in display technology, the combination of red, green, and blue (RGB three primary colors) is the basis for constructing a wide range of colors. Therefore, the addition of red phosphor can generate more saturated red and richer, more delicate colors.

[0042] Optionally, in some embodiments, the phosphor 4 is yellow. The yellow phosphor can work together with the directly emitted blue and green light to supplement the yellow part of the light source. It can also indirectly enhance the saturation and naturalness of the overall color by synthesizing white light with blue light or synthesizing richer intermediate colors with green and blue light.

[0043] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, both the blue light multi-quantum well layer 551 and the green light multi-quantum well layer 552 are composed of an InGaN barrier layer and an InGaN well layer. The InGaN barrier layer of the green light multi-quantum well layer 552 has a thickness of 5-25 nm, an In content of 20%-85%, and an emission wavelength of 515-550 nm, covering the green light region, thereby enhancing the green performance of the LED chip and widening the overall color gamut. The InGaN well layer of the green light multi-quantum well layer 552 has a thickness of 1-7 nm and an In content of 1%-25%, aiming to optimize the green light... To improve light emission efficiency and ensure good electronic structure matching between the barrier layer and the light source, promoting efficient transitions between energy levels, the InGaN barrier layer of the blue light multi-quantum well layer 551 has a thickness of 5-25 nm, an In content of 10%-40%, and an emission wavelength of 440-470 nm. Blue light is the basic light source for LEDs, providing efficient energy for subsequent phosphor excitation. The InGaN well layer of the blue light multi-quantum well layer 551 has a thickness of 1-7 nm and an In content of 1%-25%, echoing the well layer design in the green light multi-quantum well layer 552, in order to optimize the blue light emission efficiency and the overall performance of the device.

[0044] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, a p-type GaN layer 56 is disposed above the multi-quantum well layer 55, the thickness of the p-type GaN layer 56 being approximately 50-250 nm, and the Mg doping concentration being greater than 10. 18 / cm 3 Below the multiple quantum well layer 55, an N-type GaN layer 54 is disposed, the thickness of the N-type GaN layer 54 being approximately 0.5-5 μm, and the Si doping concentration being greater than 10. 18 / cm 3 The N-type GaN layer 54 provides electrons, and the P-type GaN layer 56 provides holes. The P-type GaN layer 56 and the N-type GaN layer 54 together form a PN junction. The LED chip 5 is a traditional LED chip with a single PN junction, or a high-voltage LED chip with multiple PN junctions connected in series and parallel at the chip level, or a structure of multiple independent PN junctions integrated on the same substrate. The N-type GaN4 layer introduces excess electrons by doping silicon (Si), becoming the source of electrons. The P-type GaN layer introduces a state lacking electrons, i.e., holes, by doping magnesium (Mg), becoming positive charge carriers. When the LED chip is powered on, electrons and holes are injected from the P-type layer and the N-type layer into the multi-quantum well region under the action of the electric field. When electrons and holes recombine in the multi-quantum well layer 55, electrons jump from the conduction band to the valence band, filling the holes, and the excess energy is released in the form of photons.

[0045] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, an undoped GaN layer 53 is disposed below the N-type GaN layer 54. The thickness of the undoped GaN layer 53 is 0.5-3 μm. As a lattice matching layer, the undoped GaN layer 53 can effectively alleviate the mismatch stress caused by the difference in lattice constants between GaN and substrates of different materials, such as sapphire or silicon, and reduce the dislocation density, thereby improving the overall crystal quality and reliability of the device. An undoped GaN layer, acting as a barrier layer between the N-type GaN layer 53 and the substrate 51, helps to prevent or reduce the direct penetration of electrons into the substrate 51, thereby optimizing the electrical performance of the device. The LED chip 5 includes a substrate 51, which is made of sapphire, silicon, or gallium nitride. A GaN buffer layer 52, with a thickness of 20-40 nm, is disposed between the undoped GaN layer 53 and the substrate 51. The main function of the GaN buffer layer 52 is to bridge the lattice differences between the substrate 51 and the GaN layer. Through gradual growth, it effectively reduces dislocations caused by lattice mismatch, thereby improving the crystal quality of subsequent epitaxial layers. Furthermore, it helps improve material adhesion, providing a flatter and more uniform growth platform for the top layer structure.

[0046] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the total number of multiple quantum well layers 55 is at least two, including one blue multiple quantum well layer 551 and one green multiple quantum well layer 552. The presence of at least one blue multiple quantum well layer 551 and one green multiple quantum well layer 552 lays the foundation for a wide color gamut LED. Blue light serves as the primary excitation source for LED light emission, while green light can broaden the color gamut and enhance color saturation. The combination of the two can initially achieve good coverage of the blue and green regions, laying the foundation for achieving wide color gamut light emission.

[0047] Optionally, in some embodiments, the total number of layers in the multi-quantum-well layer 55 is 5-10. By adjusting the total number of layers in the multi-quantum-well layer, the light output intensity and spectral characteristics of the LED can be controlled. The range of 5 to 10 layers ensures sufficient quantum wells to improve luminous efficiency, while avoiding increased complexity and potential efficiency degradation caused by excessive stacking.

[0048] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the encapsulation mechanism includes a support cup 2, which is made of a transparent material. The support cup 2 is fixedly connected to the support 1 and is sleeved over the encapsulating adhesive 3. The support cup 2 provides physical support for the encapsulating adhesive 3. Made of a transparent material, the support cup 2 can serve as an optical channel, allowing the light emitted by the LED chip and the light converted by the phosphor to be transmitted smoothly without affecting the luminous efficiency and optimizing the light distribution.

[0049] Optionally, in some embodiments, the support cup 2 is made of an opaque material, which can act as a light barrier to shield unwanted stray light, guide light to a specific direction, and improve the directionality of the light source.

[0050] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, both the positive and negative electrodes of the LED chip 5 are soldered with bonding wires 7. The bonding wires 7 are made of one of the following materials: gold wire, silver wire, copper wire, aluminum wire, or alloy wire. One end of the bonding wire 7 is fixedly connected to the bracket 1, and the bracket 1 is electrically connected to the LED chip 5 through the bonding wires 7. The bonding wires 7 allow current to be transmitted from the external circuit to the LED chip 5 via the bracket 1, activating the PN junction and generating light.

[0051] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the side of the LED chip 5 that contacts the bracket 1 is coated with die bond adhesive 6, and the LED chip 5 is fixedly connected to the bracket 1 through the die bond adhesive 6.

[0052] Optionally, in some embodiments, when the LED chip 51 is a top-mounted chip, the die bond 6 is one of silicone, epoxy resin or silicone doped with alumina; when the LED chip 51 is a vertical chip, the die bond 6 is one of conductive silver paste or solder paste; when the LED chip 51 is a flip chip, the die bond 6 is one of gold-tin paste, solder paste or silver paste.

[0053] Furthermore, as a preferred embodiment of the invention and not a limitation thereof, a plurality of the blue multi-quantum well layers 551 and a plurality of the green multi-quantum well layers 552 are stacked alternately. By alternating the arrangement of blue and green multi-quantum well layers in the structure, not only can efficient emission in their respective wavelength bands be obtained, but also fine harmonization and expansion of the spectrum can be achieved through the superposition effect of the two. Alternating stacking of multi-quantum well layers of different wavelengths helps to improve the light absorption and conversion efficiency. The blue layer is responsible for the basic high-intensity excitation, while the green layer supplements and adjusts the color temperature. Under their synergistic effect, high brightness output is ensured, and the color distribution is more uniform and natural, reducing color deviation.

[0054] Optionally, in some embodiments, a plurality of the blue multiple quantum well layers 551 and a plurality of the green multiple quantum well layers 552 are stacked in groups, i.e., all the blue multiple quantum well layers 551 are stacked first, followed by all the green multiple quantum well layers 552, or all the green multiple quantum well layers 552 are stacked first, followed by all the blue multiple quantum well layers 551. Group stacking simplifies the manufacturing process, avoids the complex and precise control required during the alternating deposition of quantum well layers of different wavelengths, reduces manufacturing difficulty and cost, and improves production efficiency. Since the interface properties between similar quantum well layers are similar, group stacking helps to reduce interface defects, improve the internal consistency of the device, and thus improve the overall photoelectric conversion efficiency and reliability.

[0055] Optionally, in some embodiments, a plurality of the blue light multi-quantum well layers 551 and a plurality of the green light multi-quantum well layers 552 are randomly stacked. Random stacking results in a certain degree of randomness in the spectral output. This randomness may be regarded as an advantage in certain specific applications, such as simulating the complex spectral changes of natural light, or creating more natural and irregular light and shadow effects in certain lighting applications.

[0056] A method for producing a high color gamut LED packaging structure includes the following steps:

[0057] Step 1: Growing the epitaxial layer. The epitaxial layer for the LED chip is grown using metal compound vapor deposition.

[0058] Step 2: Fabricate LED chips, including electrodes, current spreading layer, current blocking layer, protective layer, reflective layer, etc., and finally cut them into individual LED chips.

[0059] Step 3: Die bonding, fixing the LED chip onto the bracket;

[0060] Step 4: Wire bonding, which uses bonding wires to form an electrical connection between the substrate and the chip;

[0061] Step 5: Apply fluorescent adhesive by dispensing or spraying. Preferably, the fluorescent powder in the fluorescent adhesive is a red fluoride fluorescent powder.

[0062] Step Six: Test the packaging.

[0063] Step one also includes the following steps:

[0064] S1. Pre-treat the substrate by heating the reaction chamber to 1000-1200℃ to bake the substrate, removing moisture and impurities from the substrate surface and improving the adhesion of the subsequent epitaxial layer. The time should be controlled between 5-20 minutes to achieve the best cleaning effect.

[0065] S2. Adjust the temperature of the reaction chamber to the range of 400 to 600°C. This temperature range is conducive to the stable growth of GaN material and reduces strain and defects during the growth process. Using vapor deposition technology, a GaN buffer layer with a thickness of 20 to 40 nm is grown, providing a smooth, uniform and low-defect substrate for the subsequent growth of epitaxial layers.

[0066] S3. Adjust the temperature of the reaction chamber to 1000-1200℃ to grow an undoped GaN layer with a thickness of 0.5-3μm, which serves as the basis for subsequent doping layers and further enhances structural stability and electrical performance.

[0067] S4. Adjust the temperature of the reaction chamber to 1000-1200℃, and grow an N-type doped GaN layer with a thickness of approximately 0.5 to 5 μm by introducing silicon (Si) as a dopant into the reaction gas. The silicon doping concentration is controlled to be higher than 1×10^18 atoms / cm³ to ensure high conductivity.

[0068] S5. Adjust the reaction chamber temperature to the range of 650-950℃ to lay the foundation for high-quality growth of InGaN materials. When growing green quantum well layers, set the thickness of the green quantum well barrier layer to 5 to 25 nm, the In content to the range of 20%-85%, the well layer thickness to 1-7 nm, and the target wavelength to 515 to 550 nm. When growing blue quantum well layers, set the thickness of the blue quantum well barrier layer to 5 to 25 nm, the In content to the range of 10%-40%, the well layer thickness to 1-7 nm, and the target wavelength to the range of 440 to 470 nm.

[0069] S6. Adjust the temperature of the reaction chamber to 900-1100℃ to grow a P-type GaN layer. Within this temperature range, by adding magnesium (Mg) as a dopant element, grow a P-type GaN layer with a thickness of about 50 to 250 nm. The magnesium (Mg) doping concentration is >1×10^18 / cm³ to ensure effective hole injection.

[0070] S7. Annealing is performed at a temperature below 800℃ to release stress, stabilize the crystal structure, and enhance device performance and reliability.

[0071] S8. Complete electrical connections, cut into individual chips, and prepare for packaging and final testing.

[0072] As shown in Figures 1 to 3, the implementation method of Example 1 is as follows:

[0073] A high color gamut LED packaging structure and its manufacturing method are disclosed, comprising a support 1, which provides physical support and electrical connection for components mounted on the support 1. An LED chip 5 is mounted on the top surface of the support 1. The LED chip 5 is a standard-mount chip. The substrate 51 is made of sapphire, which has extremely high chemical and thermal stability, making it suitable for the high-temperature environment during LED growth. The LED chip 5 is encapsulated with a packaging mechanism, which includes an encapsulating adhesive 3. The encapsulating adhesive 3 is made of PCT (polycyclohexane terephthalate) injection molding compound. Phosphor 4 is mixed in the encapsulating adhesive 3. The phosphor and encapsulating adhesive are mixed together to form a phosphor adhesive. The phosphor particles account for 0%-90% of the weight of the phosphor adhesive. The encapsulating adhesive is made of silicone. The phosphor material is preferably a fluoride.

[0074] The LED chip 5 includes a multi-quantum well layer 55, which is used to generate light of different wavelengths. The multi-quantum well layer 55 includes a plurality of blue light multi-quantum well layers 551 and a plurality of green light multi-quantum well layers 551.

[0075] LED chip 5 serves as the light-emitting element, containing a multi-quantum-well layer 55. The multi-quantum-well layer 55 is composed of multiple very thin semiconductor layers, capable of altering the recombination process of electrons and holes through quantum confinement effects, thereby controlling the energy of the released photons, i.e., the wavelength of light. Blue and green multi-quantum-well layers 551 are responsible for generating blue and green light, respectively. By controlling the structure and materials of these multi-quantum-wells, light in specific wavelength bands can be effectively generated, laying the foundation for high color gamut displays.

[0076] The phosphor 4 is red. Through the conversion effect of the red phosphor, the LED light source can obtain red light components in addition to the directly emitted blue and green light, which significantly broadens the color gamut coverage of the light source. Specifically, in display technology, the combination of red, green, and blue (RGB three primary colors) is the basis for constructing a wide range of colors. Therefore, the addition of red phosphor can generate more saturated red and richer, more delicate colors.

[0077] Both the blue light multi-quantum well layer 551 and the green light multi-quantum well layer 552 are composed of an InGaN barrier layer and an InGaN well layer. The InGaN barrier layer of the green light multi-quantum well layer 552 has a thickness of 5-25 nm, an In content of 20%-85%, and an emission wavelength of 515-550 nm, covering the green light region, thereby enhancing the green performance of the LED chip and widening the overall color gamut. The InGaN well layer of the green light multi-quantum well layer 552 has a thickness of 1-7 nm and an In content of 1%-25%, aiming to optimize the emission efficiency of green light while ensuring... The good electronic structure matching between the barrier layer and the inGaN layer promotes efficient transitions between energy levels. The thickness of the inGaN barrier layer of the blue light multi-quantum well layer 551 is 5-25nm, the in content is 10%-40%, and the emission wavelength is 440-470nm. Blue light is the basic light source of LED and provides efficient energy for subsequent phosphor excitation. The thickness of the inGaN well layer of the blue light multi-quantum well layer 551 is 1-7nm, and the in content is 1%-25%. This design corresponds to the well layer design in the green light multi-quantum well layer 552 to optimize the emission efficiency of blue light and the overall performance of the device.

[0078] A p-type GaN layer 56 is disposed above the multi-quantum well layer 55. The thickness of the p-type GaN layer 56 is approximately 50-250 nm, and the Mg doping concentration is greater than 10. 18 / cm 3 Below the multiple quantum well layer 55, an N-type GaN layer 54 is disposed, the thickness of the N-type GaN layer 54 being approximately 0.5-5 μm, and the Si doping concentration being greater than 10. 18 / cm 3 The N-type GaN layer 54 provides electrons, and the P-type GaN layer 56 provides holes. The P-type GaN layer 56 and the N-type GaN layer 54 together form a PN junction. The N-type GaN4 layer introduces excess electrons by doping with silicon (Si), becoming the source of electrons. The P-type GaN layer introduces a state lacking electrons, i.e., holes, by doping with magnesium (Mg), becoming positive charge carriers. When the LED chip is powered on, electrons and holes are injected from the P-type layer and the N-type layer into the multi-quantum well region under the action of the electric field. When electrons and holes recombine in the multi-quantum well layer 55, electrons jump from the conduction band to the valence band to fill the holes, and the excess energy is released in the form of photons.

[0079] Below the N-type GaN layer 54, an undoped GaN layer 53 is disposed. The thickness of the undoped GaN layer 53 is 0.5-3 μm. As a lattice matching layer, the undoped GaN layer 53 can effectively alleviate the mismatch stress caused by the difference in lattice constant between GaN and substrates of different materials, such as sapphire or silicon, and reduce the dislocation density, thereby improving the overall crystal quality and reliability of the device. An undoped GaN layer, acting as a barrier layer between the N-type GaN layer 53 and the substrate 51, helps to prevent or reduce the direct penetration of electrons into the substrate 51, thereby optimizing the electrical performance of the device. The LED chip 5 includes a substrate 51 made of sapphire. Sapphire substrates have extremely high chemical and thermal stability, making them suitable for the high-temperature environment during LED growth. A GaN buffer layer 52, with a thickness of 20-40 nm, is disposed between the undoped GaN layer 53 and the substrate 51. The main function of the GaN buffer layer 52 is to bridge the lattice differences between the substrate 51 and the GaN layer. Through progressive growth, it effectively reduces dislocations caused by lattice mismatch, thereby improving the crystal quality of subsequent epitaxial layers. Furthermore, it helps improve material adhesion, providing a flatter and more uniform growth platform for the top layer structure.

[0080] The multi-quantum well layer 55 has a total of two layers, including a blue multi-quantum well layer 551 and a green multi-quantum well layer 552. These two layers lay the foundation for a wide color gamut LED. Blue light serves as the primary excitation source for LED light emission, while green light broadens the color gamut and enhances color saturation. The combination of these two layers allows for preliminary and good coverage of the blue and green regions.

[0081] The encapsulation mechanism includes a support cup 2 made of a transparent material. The support cup 2 is fixedly connected to the support 1 and is fitted over the encapsulating adhesive 3. The support cup 2 provides physical support for the encapsulating adhesive 3. Made of transparent material, the support cup 2 acts as an optical channel, allowing light emitted by the LED chip and light converted by the phosphor to pass through smoothly without affecting luminous efficiency and optimizing light distribution.

[0082] Both the positive and negative electrodes of the LED chip 5 are soldered with bonding wires 7. The bonding wires 7 are made of gold wire, which possesses superior conductivity, good corrosion resistance, and stability under high temperature and humidity conditions. The use of gold wire ensures long-term electrical connection reliability, reduces the risk of open circuits or short circuits, thereby improving the stability and lifespan of the entire LED device. One end of the bonding wire 7 is fixedly connected to the bracket 1, and the bracket 1 is electrically connected to the LED chip 5 via the bonding wire 7. The bonding wire 7 allows current to be transmitted from the external circuit through the bracket 1 to the LED chip 5, activating the PN junction and generating light.

[0083] The side of the LED chip 5 that contacts the bracket 1 is coated with die bond adhesive 6. The LED chip 5 is fixedly connected to the bracket 1 through the die bond adhesive 6, and the die bond adhesive 6 is made of silicone.

[0084] A plurality of blue quantum well layers 551 and a plurality of green quantum well layers 552 are stacked alternately. By alternating the arrangement of blue and green quantum well layers in the structure, not only can efficient emission in their respective wavelength bands be obtained, but also fine harmonization and expansion of the spectrum can be achieved through the superposition effect of the two. The alternating stacking of quantum well layers of different wavelengths helps to improve the light absorption and conversion efficiency. The blue layer is responsible for the basic high-intensity excitation, while the green layer supplements and adjusts the color temperature. Under their synergistic effect, high brightness output is ensured, and the color distribution is more uniform and natural, reducing color deviation.

[0085] A method for producing a high color gamut LED packaging structure includes the following steps:

[0086] Step 1: Growing the epitaxial layer. The epitaxial layer for the LED chip is grown using metal compound vapor deposition.

[0087] Step 2: Fabricate LED chips, including electrodes, current spreading layer, current blocking layer, protective layer, reflective layer, etc., and finally cut them into individual LED chips.

[0088] Step 3: Die bonding, fixing the LED chip onto the bracket;

[0089] Step 4: Wire bonding, which uses bonding wires to form an electrical connection between the substrate and the chip;

[0090] Step 5: Apply fluorescent adhesive by dispensing or spraying. Preferably, the fluorescent powder in the fluorescent adhesive is a red fluoride fluorescent powder.

[0091] Step Six: Test the packaging.

[0092] Step one also includes the following steps:

[0093] S1. Pre-treat the substrate by heating the reaction chamber to 1000-1200℃ to bake the substrate, removing moisture and impurities from the substrate surface and improving the adhesion of the subsequent epitaxial layer. The time should be controlled between 5-20 minutes to achieve the best cleaning effect.

[0094] S2. Adjust the temperature of the reaction chamber to the range of 400 to 600°C. This temperature range is conducive to the stable growth of GaN material and reduces strain and defects during the growth process. Using vapor deposition technology, a GaN buffer layer with a thickness of 20 to 40 nm is grown, providing a smooth, uniform and low-defect substrate for the subsequent growth of epitaxial layers.

[0095] S3. Adjust the temperature of the reaction chamber to 1000-1200℃ to grow an undoped GaN layer with a thickness of 0.5-3μm, which serves as the basis for subsequent doping layers and further enhances structural stability and electrical performance.

[0096] S4. Adjust the temperature of the reaction chamber to 1000-1200℃, and grow an N-type doped GaN layer with a thickness of approximately 0.5 to 5 μm by introducing silicon (Si) as a dopant into the reaction gas. The silicon doping concentration is controlled to be higher than 1×10^18 atoms / cm³ to ensure high conductivity.

[0097] S5. Adjust the reaction chamber temperature to the range of 650-950℃ to lay the foundation for high-quality growth of InGaN materials. When growing green quantum well layers, set the thickness of the green quantum well barrier layer to 5 to 25 nm, the In content to the range of 20%-85%, the well layer thickness to 1-7 nm, and the target wavelength to 515 to 550 nm. When growing blue quantum well layers, set the thickness of the blue quantum well barrier layer to 5 to 25 nm, the In content to the range of 10%-40%, the well layer thickness to 1-7 nm, and the target wavelength to the range of 440 to 470 nm.

[0098] S6. Adjust the temperature of the reaction chamber to 900-1100℃ to grow a P-type GaN layer. Within this temperature range, by adding magnesium (Mg) as a dopant element, grow a P-type GaN layer with a thickness of about 50 to 250 nm. The magnesium (Mg) doping concentration is >1×10^18 / cm³ to ensure effective hole injection.

[0099] S7. Annealing is performed at a temperature below 800℃ to release stress, stabilize the crystal structure, and enhance device performance and reliability.

[0100] S8. Complete electrical connections, cut into individual chips, and prepare for packaging and final testing.

[0101] The implementation method of Example 2 is as follows:

[0102] The difference between Example 2 and Example 1 is that the LED chip 5 is a flip chip, the electrodes of the LED chip 5 face the support 1, the side of the LED chip 5 that contacts the support 1 is coated with die bond adhesive 6, the die bond adhesive 6 is solder paste, the LED chip 5 is fixedly connected and electrically connected to the support 1 through the solder paste, and the substrate 51 is made of sapphire, which has extremely high chemical and thermal stability and is suitable for the high temperature environment during LED growth.

[0103] The implementation method of Example 3 is as follows:

[0104] The difference between Example 3 and Example 1 is that the total number of layers in the multi-quantum well layer 55 is 5-10. By adjusting the total number of layers, the light output intensity and spectral characteristics of the LED can be controlled. The range of 5 to 10 layers ensures sufficient quantum wells to improve luminous efficiency, while avoiding increased complexity and potential efficiency reduction caused by excessive stacking.

[0105] Increasing the number of multi-quantum-well layers to 5-10 layers means more light-emitting units can contribute to the overall light output, providing more precise spectral tuning possibilities. More quantum-well layers increase photon generation opportunities, thereby improving luminous efficiency. More quantum-well layers also offer a wider modulation space; by adjusting the thickness of different layers, material ratios, and In content, fine-tuning of the spectrum can be achieved, resulting in a wider color gamut and higher color saturation. The multi-quantum-well layer range of 5-10 layers is designed to ensure performance improvements without sacrificing production efficiency or adding excessive complexity.

[0106] The implementation method of Example 4 is as follows:

[0107] The difference between Example 4 and Example 1 lies in that several of the blue multi-quantum well layers 551 and several of the green multi-quantum well layers 552 are stacked in groups. Specifically, all the blue multi-quantum well layers 551 are stacked first, followed by all the green multi-quantum well layers 552, or vice versa. Group stacking simplifies the manufacturing process, avoids the complex and precise control required during the alternating deposition of quantum well layers of different wavelengths, reduces manufacturing difficulty and cost, and improves production efficiency. Since the interface properties between similar quantum well layers are similar, group stacking helps reduce interface defects, improves the internal consistency of the device, and thus enhances the overall photoelectric conversion efficiency and reliability.

[0108] The implementation method of Example 5 is as follows:

[0109] The difference between Example 5 and Example 1 is that the phosphor 4 is yellow. The yellow phosphor can work together with the directly emitted blue and green light to supplement the yellow part of the light source. It can also indirectly enhance the overall color saturation and naturalness by synthesizing white light with blue light or synthesizing richer intermediate colors with green and blue light.

[0110] In summary, the LED beads manufactured using the packaging structure proposed in this invention, when powered on, exhibit an NTSC color gamut of 100%-130% composed of the blue light from the chip, the green light from the chip, and the red phosphor. This is 5%-65% higher than the color gamut of blue light-excited phosphors, approaching the color gamut of a pure chip RGB solution. However, while the color gamut of this solution is 5%-15% lower than that of a pure chip RGB solution, the cost is reduced by 30%-60%. Furthermore, this solution offers a color gamut comparable to that of a BG chip combined with phosphor, but with fewer chips, effectively reducing process time and production risks. The packaging structure of this solution achieves a color gamut and lifespan closer to the pure chip RGB solution, while significantly reducing costs. Moreover, compared to the pure chip RGB solution, the application-side driving scheme of this packaging structure is simpler, and the electrical design of the substrate is also simpler, saving design and material production costs and improving production yield. Additionally, this solution offers a color gamut comparable to that of a BG chip combined with phosphor, but with fewer chips, effectively reducing process time and production risks.

[0111] It should be understood that the terms "first," "second," etc., are used in this invention to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information. In addition, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0112] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high color gamut LED packaging structure, characterized in that, Includes a bracket (1), the function of which is to provide physical support and electrical connection for the components mounted on the bracket (1). An LED chip (5) is mounted on the top surface of the bracket (1). The LED chip (5) is of one type: upright chip, vertical chip, and flip chip. The LED chip (5) is covered with an encapsulation mechanism, which includes encapsulating glue (3). The encapsulating glue (3) contains phosphor (4), and the phosphor (4) is red. The LED chip (5) includes a multi-quantum well layer (55) for generating light of different wavelengths. The multi-quantum well layer (55) includes a number of blue multi-quantum well layers (551) and a number of green multi-quantum well layers (551).

2. The high color gamut LED packaging structure according to claim 1, characterized in that, Both the blue quantum well layer (551) and the green quantum well layer (552) are composed of an InGaN barrier layer and an InGaN well layer. The InGaN barrier layer of the green quantum well layer (552) has a thickness of 5-25 nm, an In content of 20%-85%, and an emission wavelength of 515-550 nm. The InGaN well layer of the green quantum well layer (552) has a thickness of 1-7 nm and an In content of 1%-25%. The InGaN barrier layer of the blue quantum well layer (551) has a thickness of 5-25 nm, an In content of 10%-40%, and an emission wavelength of 440-470 nm. The InGaN well layer of the blue quantum well layer (551) has a thickness of 1-7 nm and an In content of 1%-25%.

3. The high color gamut LED packaging structure according to claim 1, characterized in that, A P-type GaN layer (56) is disposed above the multi-quantum well layer (55), and an N-type GaN layer (54) is disposed below the multi-quantum well layer (55). The N-type GaN layer (54) provides electrons, and the P-type GaN layer (56) provides holes. The P-type GaN layer (56) and the N-type GaN layer (54) together form a PN junction.

4. The high color gamut LED packaging structure according to claim 3, characterized in that, An undoped GaN layer (53) is disposed below the N-type GaN layer (54), the LED chip (5) includes a substrate (51), and a GaN buffer layer (52) is disposed between the undoped GaN layer (53) and the substrate (51).

5. The high color gamut LED packaging structure according to claim 1, characterized in that, The encapsulation mechanism includes a support cup (2), which is made of transparent or opaque material. The support cup (2) is fixedly connected to the support (1) and is sleeved on the encapsulation adhesive (3).

6. The high color gamut LED packaging structure according to claim 1, characterized in that, The positive and negative electrodes of the LED chip (5) are both welded with bonding wires (7). One end of the bonding wire (7) is fixedly connected to the bracket (1). The bracket (1) is electrically connected to the LED chip (5) through the bonding wire (7).

7. The high color gamut LED packaging structure according to claim 1, characterized in that, The side of the LED chip (5) that contacts the bracket 1 is coated with die bond adhesive (6), and the LED chip (5) is fixedly connected to the bracket (1) through the die bond adhesive (6).

8. The high color gamut LED packaging structure according to claim 1, characterized in that, A plurality of the blue light multi-quantum well layers (551) and a plurality of the green light multi-quantum well layers (552) are stacked alternately.

9. A method for producing a high color gamut LED packaging structure according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Growing the epitaxial layer. The epitaxial layer for the LED chip is grown using metal compound vapor deposition. Step 2: Fabricate LED chips, including electrodes, current spreading layer, current blocking layer, protective layer, reflective layer, etc., and finally cut them into individual LED chips. Step 3: Die bonding, fixing the LED chip onto the bracket; Step 4: Wire bonding, which uses bonding wires to form an electrical connection between the substrate and the chip; Step 5: Apply fluorescent adhesive by dispensing or spraying it onto one side of the functional area of ​​the bracket. Preferably, the fluorescent powder in the fluorescent adhesive is a red fluoride fluorescent powder. Step Six: Test the packaging.

10. The method for producing a high color gamut LED packaging structure according to claim 1, characterized in that, Step one also includes the following steps: Adjusting the reaction chamber temperature to the range of 650-950℃ lays the foundation for high-quality growth of InGaN materials. When growing the green quantum well layer (552), the thickness of the green quantum well barrier layer is set to 5 to 25 nm, the In content is set to 20%-85%, the well layer thickness is set to 1-7 nm, and the target wavelength is locked in the range of 515 to 550 nm. When growing the blue quantum well layer (551), the thickness of the blue quantum well barrier layer is set to 5 to 25 nm, the In content is set to 10%-40%, the well layer thickness is set to 1-7 nm, and the target wavelength is locked in the range of 440 to 470 nm.

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