LED packaging structure and light-emitting device

Abstract

The invention provides an LED packaging structure and a light emitting device. The LED packaging structure comprises a substrate; the LED chips are arranged on the substrate in a matrix form of at least 2 * 2, one side, far away from the substrate, of each LED chip is a light emitting side, and the light emitting angle is smaller than or equal to 130 degrees; the fluorescence conversion layer is positioned on the LED chip, covers the light-emitting surface of the LED chip, and is used for receiving the light with the first wavelength from the LED chip and at least partially converting the light into light with a second wavelength to be emitted; the thickness T of the fluorescence conversion layer is less than or equal to 50 [mu] m. According to the technical scheme, multiple refraction and secondary excitation of light in the fluorescent layer are reduced by controlling multiple parameters of the packaging structure, packaging is simplified by sharing the fluorescent conversion layer, the number of retaining walls is reduced, the process difficulty and the production cost are reduced, and the technical scheme provided by the invention is particularly suitable for small-size products such as Micro LEDs.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to an LED packaging structure and a light-emitting device. Background Technology

[0002] To enable LEDs to emit light of a specific color, a phosphor conversion layer needs to be placed on the LED chip that emits blue or ultraviolet light. This layer absorbs the light emitted by the chip and converts it into light of different wavelengths, thereby achieving white light or light of a specific color output.

[0003] When an LED chip in an LED matrix is ​​lit, some of its excitation light is emitted in a fan shape along the axial and lateral directions, entering the phosphor conversion layer covering it. This laterally propagated light undergoes multiple refractions and reflections within the phosphor conversion layer, simultaneously exciting the phosphors in adjacent pixel areas. This causes pixels that should be dark to exhibit phenomena such as flooding and yellowing, severely reducing image contrast and clarity, and limiting the performance of LED chips in precision lighting applications such as high-end pixel headlights.

[0004] To suppress crosstalk, existing technologies typically place physical light-blocking walls, such as silicon layers, between chips to prevent adjacent LEDs from interfering with each other's light output. However, this also increases process complexity and cost, and affects the filling of other functional layers between LED chips, resulting in overall brightness loss. Summary of the Invention

[0005] In view of the defects and deficiencies in the prior art described above, this application provides an LED packaging structure and light-emitting device that can ensure high luminous efficiency while suppressing light crosstalk within the phosphor layer.

[0006] In a first aspect, this application provides an LED packaging structure, comprising at least: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate, with the side of the LED chip away from the substrate being the light-emitting side and the light-emitting angle being less than or equal to 130°. A fluorescence conversion layer is located on top of the LED chip and covers the light-emitting surface of the LED chip. It is used to receive light of a first wavelength from the LED chip and convert it at least partially into light of a second wavelength for emission. The thickness T of the fluorescence conversion layer is less than or equal to 50 μm.

[0007] Secondly, this application provides an LED packaging structure, comprising at least: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate. The epitaxial layer thickness of the LED chips is less than 12μm. The side of the LED chips away from the substrate is the light-emitting side and the light-emitting angle is less than or equal to 130°. A phosphor conversion layer, located above and covering the light-emitting surface of the LED chip, is used to receive light of a first wavelength from the LED chip and at least partially convert it into light of a second wavelength for emission; the thickness T of the phosphor conversion layer is less than or equal to 50 μm, and the weight percentage Wt of the phosphor is less than 75%; An adhesion layer is located between the LED chip and the phosphor conversion layer, and surrounds and fills the gaps between the LED chips; the refractive index of the adhesion layer is less than 1.5.

[0008] Thirdly, this application provides a light-emitting device, including a driving substrate and a plurality of LED packaging structures. The driving substrate has a driving device layer and a driving circuit layer formed therein. The LED packaging structure includes the LED packaging structure provided by any of the above technical solutions. The driving circuit layer is electrically connected to the LED packaging structure.

[0009] Compared with the prior art, the LED packaging structure and light-emitting device provided in this application have the following advantages: The technical solution of this application reduces multiple refractions and secondary excitations of light in the phosphor layer by controlling various parameters of the packaging structure, such as controlling the phosphor layer thickness to be less than or equal to 50μm. It simplifies packaging by sharing the phosphor conversion layer and reduces the number of barrier settings, thereby reducing process difficulty and production costs. The technical solution provided by this application is particularly suitable for small-sized products such as Micro LED.

[0010] In addition, the light-emitting device provided in this application includes the light-emitting diode provided in the above-mentioned technical solution. Therefore, the light-emitting device also has the above-mentioned good technical effects. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the LED packaging structure provided in Embodiment 1 of this application; Figure 2 This is a top view of the LED packaging structure provided in Embodiment 1 of this application; Figure 3 This is a schematic diagram of the LED packaging structure provided in Embodiment 2 of this application; Figures 4 to 6 A comparison diagram of the light output quality of the product with the technical solution of this application and the product with existing technology; Figure 7 This is a schematic diagram of the structure of the light-emitting device provided in Embodiment 3 of this application.

[0012] List of reference numerals in the attached diagram: 10. Substrate; 20. LED chip; 30. Adhesion layer; 40. Fluorescent conversion layer; 41. First part; 42. Second part; 101. Driving substrate; 102. LED packaging structure. Detailed Implementation

[0013] Based on the technical deficiencies of the prior art, this application provides an LED packaging structure, comprising at least: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate, with the side of the LED chip away from the substrate being the light-emitting side and the light-emitting angle being less than or equal to 130°. A phosphor conversion layer, located above the LED chip and covering its light-emitting surface, receives light of a first wavelength from the LED chip and at least partially converts it into light of a second wavelength for emission. The thickness T of the phosphor conversion layer is less than or equal to 50 μm. By controlling the emission angle of the LED chip to be no greater than 130° and the thickness of the phosphor conversion layer to be no greater than 50 μm, the lateral diffusion of light is limited from both the light source and the light path dimensions, thus initially achieving the purpose of preventing crosstalk in the LED matrix.

[0014] In some embodiments, the phosphor weight percentage (Wt) in the fluorescence conversion layer is less than 75%. By limiting the phosphor weight percentage (Wt) to < 75%, sufficient light conversion capability is ensured while reducing the light scattering probability within the fluorescence layer, further improving light extraction efficiency and suppressing optical crosstalk.

[0015] In some embodiments, the thickness T of the fluorescence conversion layer and the weight percentage Wt of the phosphor satisfy the following relationship: 150≤T×Wt%≤3750, where T≤50μm and Wt%<75%. By limiting the relative relationship between the thickness T and the phosphor weight percentage Wt%, precise control of the phosphor layer performance is achieved synergistically, reaching a relative balance between high luminous efficacy and low crosstalk.

[0016] In some embodiments, the thickness T of the phosphor conversion layer and the spacing D of the LED chip satisfy the following relationship: 1 ≤ T / D ≤ 25. This is to maintain device density and light output brightness while effectively suppressing optical crosstalk.

[0017] In some embodiments, the epitaxial layer thickness of each LED chip is less than 12 μm. A thinner epitaxial layer can reduce internal absorption losses as light propagates within the chip, thereby improving the light extraction efficiency of the LED chip itself.

[0018] In some implementations, the gap width between adjacent LED chips is from 1 μm to 200 μm. This gap width can prevent light from escaping from the gap or entering the adjacent chip area, while maintaining sufficient pixel density.

[0019] In some implementations, a chip matrix consisting of multiple LED chips shares a single phosphor conversion layer. This simplifies the packaging process and improves the color consistency of phosphor conversion.

[0020] In some embodiments, an adhesive layer is also included, located between the LED chip and the phosphor conversion layer, and surrounding and filling the gaps between the LED chips; the refractive index of the adhesive layer is less than 1.5. By providing a low-refractive-index adhesive layer and filling the chip gaps, a lateral light barrier is formed in the sidewall region of the LED chip, improving the axial emission efficiency of light.

[0021] In some embodiments, the material of the adhesive layer includes one or more of silicone, silica, epoxy resin, or acrylate.

[0022] In some embodiments, the fluorescence conversion layer includes a first portion located above the light-emitting surface of the LED chip and a second portion extending downwards to fill the gaps between the LED chips; wherein the first portion located above the light-emitting surface of the LED chip has a thickness of less than or equal to 50 μm. The fluorescence conversion layer simultaneously covers the light-emitting surface of the chip and fills the gaps to reduce light propagation in the gaps and prevent light leakage.

[0023] In some embodiments, the material of the fluorescence conversion layer includes a ceramic phosphor sheet, a glass phosphor sheet, or a silicone phosphor film doped with phosphor.

[0024] In some embodiments, the LED chip is a vertically structured Micro LED chip.

[0025] This application also provides an LED packaging structure, comprising at least: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate. The epitaxial layer thickness of the LED chips is less than 12μm. The side of the LED chips away from the substrate is the light-emitting side and the light-emitting angle is less than or equal to 130°. A phosphor conversion layer, located above and covering the light-emitting surface of the LED chip, is used to receive light of a first wavelength from the LED chip and at least partially convert it into light of a second wavelength for emission; the thickness T of the phosphor conversion layer is less than or equal to 50 μm, and the weight percentage Wt of the phosphor is less than 75%; An adhesion layer is located between the LED chip and the phosphor conversion layer, and surrounds and fills the gaps between the LED chips; the refractive index of the adhesion layer is less than 1.5.

[0026] This application also provides a light-emitting device, including a driving substrate and a plurality of LED packaging structures. The driving substrate has a driving device layer and a driving circuit layer formed therein. The LED packaging structures include the LED packaging structures provided in any of the above-described technical solutions. The driving circuit layer is electrically connected to the LED packaging structures. This light-emitting device provides higher brightness, contrast, and imaging quality in terminal products such as displays and backlight modules.

[0027] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0028] Example 1: This embodiment provides an LED packaging structure, see [link / reference] Figure 1 and Figure 2 The packaging structure includes at least a substrate 10, an LED chip 20, an adhesive layer 30, and a phosphor conversion layer 40. The specific structure and technical solution of the LED packaging structure provided in this embodiment will be described in detail below.

[0029] See Figure 1 and Figure 2 The substrate 10 can be a wiring substrate connected to the LED chip electrodes, or a substrate without wire patterns. For example, if the side of the LED chip 20 closest to the substrate 10 is the main light-emitting surface, the LED chip 20 can be disposed on a substrate without wire patterns to improve luminous brightness. If the side of the LED chip 20 furthest from the substrate 10 is the main light-emitting surface, the substrate 10 will not cause absorption loss to the light emission, and a wiring substrate can be used, which is the substrate structure used in this embodiment. Further, the substrate 10 can be, for example, a single crystal or polycrystalline aluminum nitride, or, for example, alumina ceramic, glass, silicon, or metal, or a laminate or composite material layer composed of the above materials. The substrate 10 provided in this embodiment uses a metal-based material, which has high heat dissipation performance and is beneficial for extending the device's lifespan.

[0030] See also Figure 1 and Figure 2An LED chip 20 is disposed on a substrate 10, with the side of the chip away from the substrate 10 being the light-emitting side. The LED chips 20 are arranged on the substrate 10 in a matrix of at least 2×2, for example, in an arrangement of 8×8, 16×16, 64×64, or 128×128. The wavelength of the light emitted from the light-emitting layer of the LED chip 20 is not particularly limited; for example, it can be a semiconductor light-emitting device with an emission wavelength between 240nm and 500nm, corresponding to the near-ultraviolet wavelength to the short visible wavelength range. The LED chip 20 sequentially includes an N-type semiconductor layer, an active layer, and a P-type semiconductor layer, wherein electrode layers are disposed on both the N-type and P-type semiconductor layers. For example, electrical connections are achieved with external circuits on the substrate 10 by providing pad electrodes. The pad electrodes on the LED chip 20 are connected to the external circuits through conductive structures such as metal bumps or metal solder.

[0031] In an optional embodiment, the LED chip 20 has a vertical structure, and the epitaxial layer thickness of each LED chip 20 is less than 12 μm. The light-emitting surface of a vertically structured LED has a significant difference in refractive index compared to air. For example, the refractive index of the GaN material layer is approximately 2.4, while the refractive index of air is 1. This large difference causes total internal reflection when light travels from a high-refractive-index semiconductor material to a low-refractive-index air medium, resulting in a typically narrow native emission angle and a concentrated, axially oriented light emission. Furthermore, a thinner epitaxial layer reduces the proportion of light escaping from the chip sidewalls, lowers internal absorption losses during propagation within the chip, and allows more photons to successfully exit to the phosphor layer, ultimately improving the light extraction efficiency of the LED chip itself. As an example, the epitaxial layer thickness of the LED chip 20 can be 2 μm, 4 μm, 6 μm, 8 μm, or 10 μm. Further, the epitaxial layer thickness is 4 μm to 8 μm.

[0032] In this embodiment, the LED chip 20 has its light-emitting side furthest from the substrate 10, and its emission angle is less than or equal to 130°. Furthermore, the emission angle can be further controlled by fabricating microlenses on the chip's light-emitting surface to ensure more axial emission, or by roughening or patterning the chip's light-emitting surface to optimize the emission angle, or by fabricating a highly reflective metal layer, such as an Ag reflective layer, on the chip's sidewall to concentrate the emission angle. A light source with an initial emission angle less than or equal to 130° significantly reduces the risk of light crosstalk in the device, achieving optimal anti-crosstalk performance in conjunction with the phosphor conversion layer 40.

[0033] See also Figure 1 and Figure 2The gap width D between adjacent LED chips is from 1 μm to 200 μm. For example, the gap width D can be 2 μm, 10 μm, 50 μm, 100 μm, or 150 μm. This suitable gap width prevents light from escaping through the gap or entering the adjacent chip area, while maintaining sufficient pixel density. Furthermore, a good gap width provides sufficient space for the subsequent filling of a low-refractive-index adhesive layer. Understandably, when the gap width D < 1 μm, the gap is too narrow, and the light emitted from adjacent chips may interfere with each other, causing uneven light color and brightness, and increasing the difficulty of filling the adhesive layer. Conversely, when D > 200 μm, the chip gap is too large. Although increasing the spacing can effectively prevent optical crosstalk, an excessively large gap will reduce the pixel density of the entire LED matrix, decreasing the number of light-emitting points per unit area, which is also detrimental to achieving high-resolution pixelated display or lighting. Further, the gap width D between adjacent LED chips 20 is from 10 μm to 50 μm.

[0034] See also Figure 1 and Figure 2 The LED packaging structure provided in this embodiment also includes an adhesion layer 30. The adhesion layer 30 is located between the LED chip 20 and the phosphor conversion layer 40, and surrounds and fills the gap between the LED chip 20 to enhance the bonding strength between the phosphor layer 40 and the LED chip 20, prevent the phosphor layer from falling off or shifting during product use, and improve the stability and reliability of the packaging structure or product.

[0035] In the above embodiment, the refractive index of the adhesive layer 30 is less than 1.5. By setting a low-refractive-index adhesive layer, a lateral light barrier is formed in the sidewall region of the LED chip 20, thereby improving the axial emission efficiency of light. Further, the material of the adhesive layer 30 includes one or more of silicone, silica, epoxy resin, or acrylate. The adhesive layer 30 provided in this embodiment uses silicone. Compared to other adhesive materials, silicone has high heat resistance, ensuring bonding stability, and this material has good light transmittance, preventing light loss in this layer.

[0036] See also Figure 1 and Figure 2A phosphor conversion layer 40 is disposed on top of the LED chip 20. The relative position of the phosphor conversion layer 40 and the LED chip 20 can be varied. For example, from a top view, the edge of the phosphor conversion layer 40 can be located outside the edge range of the LED chip 20, that is, the phosphor conversion layer 40 completely covers the light-emitting surface of the LED chip 20, so as to provide a more efficient wavelength conversion effect for the first wavelength light from the LED chip 20 and reduce light loss. The material of the phosphor conversion layer 40 includes ceramic phosphor sheets, glass phosphor sheets, or silicone phosphor films doped with corresponding phosphors, such as Al2O3 (alumina), AlN (aluminum nitride), phosphate glass, or silicate glass.

[0037] See also Figure 1 and Figure 2 In an optional embodiment, the thickness T of the fluorescence conversion layer 40 is less than or equal to 50 μm. For example, the thickness T of the fluorescence conversion layer 40 can be 35 μm, 40 μm, 45 μm, or 48 μm. By controlling the emission angle of the LED chip 20 to be no greater than 130° and the thickness T of the fluorescence conversion layer 40 to be no greater than 50 μm, the lateral diffusion of light is restricted from both the light source and the light path dimensions, thus initially achieving the goal of suppressing crosstalk in the LED matrix. Further, the fluorescence conversion layer 40 is a thin layer of uniform thickness, with its thickness T ranging from 35 μm to 45 μm.

[0038] In some embodiments, the weight percentage (Wt) of phosphor in the phosphor conversion layer 40 is less than 75%. By limiting the phosphor weight percentage (Wt) to <75%, sufficient light conversion capability is ensured while reducing the light scattering probability within the phosphor conversion layer 40, further improving light extraction efficiency and suppressing optical crosstalk. It is understood that the LED chip 20 radiates a first wavelength of light. When this first wavelength passes through the phosphor conversion layer 40, the phosphor converts it into a second wavelength and emits it. When the phosphor concentration is too high, a dense scattering network forms in the substrate, causing multiple scattering of photons within the phosphor conversion layer 40, resulting in photon energy loss and a reduction in the emitted second wavelength light. This ultimately manifests as low product brightness, uneven color, and other quality issues. Furthermore, the phosphor weight percentage (Wt) ranges from 40% to 70%, for example, 50%, 60%, or 65%. At this concentration, the phosphor conversion layer 40 still has a sufficient amount of phosphor to absorb most of the chip excitation light, ensuring effective wavelength conversion and preventing blue light leakage that could cause color coordinate drift.

[0039] In some embodiments, the thickness T of the phosphor conversion layer 40 and the weight percentage Wt of the phosphor satisfy the following relationship: 150 ≤ T × Wt% ≤ 3750. For example, when the phosphor conversion layer thickness T = 45 μm, the phosphor weight percentage Wt is 70%. When a thinner package is required, the phosphor conversion layer thickness T = 20 μm, and the phosphor weight percentage Wt% is 40% or 45%. By limiting the relative relationship between thickness T and phosphor weight percentage Wt%, precise control of the phosphor layer performance is achieved synergistically, reaching a relative balance between high luminous efficacy and low crosstalk. Further, the thickness T and weight percentage Wt satisfy the following relationship: 1000 ≤ T × Wt% ≤ 3000. For example, when the phosphor conversion layer thickness T = 30 μm, the phosphor weight percentage Wt is 60%. For thinner package requirements, the phosphor conversion layer thickness T = 20 μm, and the phosphor weight percentage Wt% is 70% or 75%.

[0040] In some embodiments, the thickness T of the phosphor conversion layer 40 and the spacing D of the LED chip 20 must satisfy the following relationship: 1 ≤ T / D ≤ 25. It is understandable that when T / D < 1, it indicates that the phosphor conversion layer 40 is relatively too thin or the spacing is too large. Although this helps reduce light crosstalk, from a top-view perspective, the low arrangement density of the LED chip 20 leads to reduced light emission uniformity and limited brightness, which is not conducive to optimizing the overall performance of the device. An excessively small T / D ratio may also result in insufficient absorption of excitation light by the phosphor conversion layer 40, causing blue light leakage and color quality problems. Conversely, when T / D > 25, it indicates that the phosphor conversion layer 40 is relatively too thick or the spacing is too small. Light emitted from the light-emitting sidewall of the LED chip 20 or at a large angle needs to travel a longer lateral propagation path within this thickness of phosphor conversion layer 40, making it easier for the light to excite phosphors in adjacent areas, exacerbating light crosstalk. Furthermore, an excessively thick phosphor conversion layer 40 also increases the overall absorption and scattering loss of photons, which is not conducive to improving light emission efficiency. As an example, for high pixel density products, such as LED chip spacing D of 2μm to 10μm, the phosphor conversion layer thickness T is 40μm to 50μm; for products requiring uniformity, such as LED chip spacing D of 40μm to 50μm, the phosphor conversion layer thickness T is 40μm to 50μm. Furthermore, the thickness T of the phosphor conversion layer 40 and the spacing D of the LED chip 20 simultaneously satisfy 1≤T / D≤2 and 150≤T×Wt%≤3750. These proportional constraints ensure that the phosphor conversion layer 40 has sufficient thickness for effective light conversion while limiting its lateral light propagation capability within a safe range. This ratio, combined with the scheme of an LED chip emission angle not exceeding 130°, optimizes the LED packaging structure from multiple dimensions, such as the light source divergence angle and the thickness of the propagation medium, to effectively suppress optical crosstalk while maintaining device density and output brightness. Furthermore, the thickness T of the phosphor conversion layer 40 and the spacing D of the LED chip 20 must satisfy the following relationship: 2≤T / D≤10.

[0041] In some implementations, the number of each LED chip 20 and the number of phosphor conversion layers 40 covering it can be in a one-to-one correspondence or not entirely corresponding, for example... Figure 1 and Figure 2 The LED packaging structure shown has a phosphor conversion layer 40 disposed on each of two or more LED chips 20, or even a chip matrix composed of multiple LED chips 20 or the entire LED matrix sharing a phosphor conversion layer 40, which simplifies the packaging process and improves the color consistency of phosphor conversion.

[0042] In addition, this embodiment also provides a specific LED packaging structure, which includes, from bottom to top: a substrate, an LED chip array, an adhesive layer, and a phosphor conversion layer.

[0043] The substrate is made of AlN ceramic substrate with high thermal conductivity, and metal wiring circuits are fabricated on its surface to provide electrical connection and good heat dissipation path for LED chip array.

[0044] The LED chip array is bonded to the substrate in a 4×4 matrix. The LED chips are vertical MicroLED chips with a spacing of about 10μm between each chip and an epitaxial layer thickness of about 8μm. The light emission angle is less than 130° to reduce large-angle scattered light that may cause crosstalk.

[0045] The adhesive layer uses silicone with a refractive index of 1.41, which is uniformly coated between the LED chip array and completely covers the light-emitting surface of the chip to achieve a firm bond to the phosphor conversion layer on it.

[0046] The phosphor conversion layer is a single sheet of glass phosphor doped with YAG phosphor, which is attached to the entire LED chip array via the following adhesion layer. The phosphor conversion layer has a thickness of 40 μm to minimize the lateral propagation path of light within the layer; the phosphor weight percentage is 65%, ensuring sufficient absorption of blue light while minimizing multiple scattering caused by excessive phosphor density.

[0047] See Figures 4 to 6 , Figure 4 The image shows the light emission effect of an existing product. Its fluorescence conversion layer is thicker than 50μm, and it can be seen that the illuminated characters have blurry edges and a yellowish tinge. Figure 5 The same light emission effect diagram of the existing product shows that its LED light emission angle is >130° and the powder weight ratio is >75%. It can be seen that the edges of the characters are illuminated, while there is a dark area in the center of the characters, and the uniformity of light emission is poor. Figure 6 The product light emission effect diagram provided in this embodiment shows that the illuminated characters have a consistent color and clear boundaries.

[0048] Example 2: This embodiment also provides an LED packaging structure, see [link to documentation]. Figure 3 The packaging structure includes at least a substrate 10, an LED chip 20, and a phosphor conversion layer 40. The differences between the light-emitting diode provided in this embodiment and that in Embodiment 1 will be described in detail below.

[0049] See Figure 3In some embodiments, the phosphor weight percentage (Wt) in the phosphor conversion layer 40 is less than 75%. The phosphor conversion layer 40 includes a first portion 41 located above the light-emitting surface of the LED chip 20, and a second portion 42 filling the gaps between the LED chips 20. In this embodiment, the second portion 42 replaces the adhesion layer in Embodiment 1 and is in direct contact with the sidewalls of the LED chip 20 and the substrate surface. Further, the thickness of the first portion 41 located above the light-emitting surface of the LED chip is less than or equal to 50 μm, for example, it can be 30 μm, 35 μm, 40 μm, or 45 μm. The above structure can be obtained by controlling the fabrication process of the phosphor conversion layer 40. For example, a silicone phosphor material doped with YAG phosphor is coated onto a fixed LED chip array. By controlling the coating process parameters, the material forms a first part 41 with a thickness of no more than 50 μm on the chip, and ensures that it can flow in and completely fill the gap between the chips to form a second part 42. After thermal curing, an integrated phosphor conversion layer 40 is obtained. In this way, the phosphor conversion layer 40 covers the light-emitting surface of the chip and fills the gap, which plays a good role in reducing the propagation of light in the gap and preventing light leakage.

[0050] In an optional embodiment, the LED chip 20 has a vertical structure, the epitaxial layer thickness of each LED chip 20 is less than 12 μm, the side of the LED chip 20 away from the substrate 10 is the light-emitting side and the emission angle is less than or equal to 130°. Further, the gap width D between adjacent LED chips is 1 μm to 20 μm.

[0051] Example 3: See Figure 7 This embodiment provides a light-emitting device, including a driving substrate 101 and an LED packaging structure 102 fixed on the driving substrate 101. The LED packaging structure 102 can be any one or more structures provided in Embodiment 1 or Embodiment 2.

[0052] It is understood that the light-emitting device may also include a housing to protect several light-emitting elements. The driving substrate 101 may also have a driving device layer and a driving circuit layer located above the driving device layer, with the driving circuit layer electrically connected to each driving device in the driving device layer. The circuit layer of the LED package structure 102 is connected to the driving circuit layer to enable the driving devices in the driving device layer to control the LED package structure 102. The light-emitting device provided in this embodiment has higher brightness, better contrast, and better imaging quality in terminal products such as displays and backlight modules.

[0053] In summary, the LED packaging structure and light-emitting device provided in this application have high industrial application value because they effectively overcome the various shortcomings of the prior art.

[0054] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An LED packaging structure, characterized in that, At least including: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate, with the side of the LED chip away from the substrate being the light-emitting side and the light-emitting angle being less than or equal to 130°. A fluorescence conversion layer is located on top of the LED chip and covers the light-emitting surface of the LED chip. It is used to receive light of a first wavelength from the LED chip and convert it at least partially into light of a second wavelength for emission. The thickness T of the fluorescence conversion layer is less than or equal to 50 μm.

2. The LED packaging structure according to claim 1, characterized in that, The phosphor in the fluorescence conversion layer has a weight percentage (Wt) of less than 75%.

3. The LED packaging structure according to claim 1, characterized in that, The thickness T of the fluorescence conversion layer and the weight percentage Wt of the phosphor satisfy the following relationship: 150≤T×Wt%≤3750, where T≤50μm and Wt%<75%.

4. The LED packaging structure according to claim 1, characterized in that, The thickness T of the fluorescence conversion layer and the spacing D of the LED chip satisfy the following relationship: 1≤T / D≤25.

5. The LED packaging structure according to claim 1, characterized in that, The epitaxial layer thickness of each LED chip is less than 12 μm.

6. The LED packaging structure according to claim 1, characterized in that, The gap width between adjacent LED chips ranges from 1μm to 200μm.

7. The LED packaging structure according to claim 1, characterized in that, A chip matrix consisting of multiple LED chips shares a single phosphor conversion layer.

8. The LED packaging structure according to claim 1, characterized in that, It also includes an adhesive layer located between the LED chip and the phosphor conversion layer, and surrounding and filling the gaps between the LED chips; the refractive index of the adhesive layer is less than 1.

5.

9. The LED packaging structure according to claim 8, characterized in that, The material of the adhesive layer includes one or more of silicone, silica, epoxy resin or acrylate.

10. The LED packaging structure according to any one of claims 1 to 7, characterized in that, The fluorescence conversion layer includes a first portion located above the light-emitting surface of the LED chip, and a second portion that fills the gaps between the LED chips downwards; wherein the thickness of the first portion located above the light-emitting surface of the LED chip is less than or equal to 50 μm.

11. The LED packaging structure according to claim 1, characterized in that, The materials of the fluorescence conversion layer include ceramic fluorescent sheets, glass fluorescent sheets, or silicone fluorescent films doped with phosphors.

12. An LED packaging structure, characterized in that, At least including: substrate; LED chips are arranged in a matrix of at least 2×2 on the substrate. The epitaxial layer thickness of the LED chips is less than 12μm. The side of the LED chips away from the substrate is the light-emitting side and the light-emitting angle is less than or equal to 130°. A phosphor conversion layer, located above and covering the light-emitting surface of the LED chip, is used to receive light of a first wavelength from the LED chip and at least partially convert it into light of a second wavelength for emission; the thickness T of the phosphor conversion layer is less than or equal to 50 μm, and the weight percentage Wt of the phosphor is less than 75%; An adhesion layer is located between the LED chip and the phosphor conversion layer, and surrounds and fills the gaps between the LED chips; the refractive index of the adhesion layer is less than 1.

5.

13. A light-emitting device, characterized in that, The device includes a driving substrate and several LED packaging structures. The driving substrate has a driving device layer and a driving circuit layer. The LED packaging structure includes the LED packaging structure according to any one of claims 1 to 12. The driving circuit layer is electrically connected to the LED packaging structure.

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