Pyramid light-emitting structure and preparation method thereof

Abstract

The application relates to the field of light-emitting structures, in particular to a pyramid light-emitting structure and a preparation method thereof, which comprises a pyramid light-emitting structure, the structure comprising a substrate, at least one light source and at least one light-emitting structure, the light source being fixed to the substrate; the light-emitting structure is arranged one by one with the light source, each light-emitting structure covering the corresponding light source, and each light-emitting structure comprising a transparent packaging part and a fluorescent conversion part; the transparent packaging part comprises a plurality of light-transmitting material layers, the refractive index of the plurality of light-transmitting material layers decreasing along the direction away from the light source; the fluorescent conversion part is arranged on the side of the transparent packaging part away from the light source, and the refractive index of the fluorescent conversion part is smaller than that of the adjacent light-transmitting material layer, so that the light-emitting efficiency and light-emitting quality are improved.

Description

Technical Field

[0001] This application relates to the field of luminescent structures, specifically to a pyramid luminescent structure and its preparation method. Background Technology

[0002] Light-emitting diode (LED) devices typically include a light source and a package structure covering the light source. The package structure contains fluorescent material. The light emitted by the light source is converted by the fluorescent material and mixed with the unconverted light before being emitted outward, forming light with the desired color temperature and color.

[0003] In existing LED packaging structures, the light emitted by the light source needs to pass through multiple interfaces during its outward propagation, such as between the packaging material and the phosphor layer, and between the packaging material and the outside air. At these interfaces, the light is reflected, with some light being reflected back into the packaging structure and unable to escape smoothly. Furthermore, it is absorbed and lost after multiple reflections within the device.

[0004] This interface reflection causes significant light energy loss, preventing the light emitted from the light source from being fully transmitted, resulting in low light extraction efficiency and affecting the light extraction efficiency and light spot uniformity of the LED device. Therefore, how to reduce the reflection loss of light at various interfaces inside the packaging structure and improve the light extraction efficiency of LED devices has become a technical problem that needs to be solved in this field. Summary of the Invention

[0005] To address the technical problems in the prior art, this application provides a pyramid-shaped light-emitting structure.

[0006] The pyramid-shaped luminous structure provided in this application adopts the following technical solution:

[0007] A pyramid-shaped luminescent structure, comprising:

[0008] substrate;

[0009] At least one light source, said light source being fixed to the substrate; and

[0010] At least one light-emitting structure is provided in one-to-one correspondence with the light source. Each light-emitting structure covers the corresponding light source. Each light-emitting structure includes a transparent encapsulation part and a fluorescence conversion part. The light-emitting structure as a whole gradually narrows from the substrate toward the direction away from the substrate.

[0011] The transparent encapsulation portion includes multiple light-transmitting material layers, and the refractive index of the multiple light-transmitting material layers decreases along the direction away from the light source;

[0012] The fluorescence conversion part is disposed on the side of the transparent encapsulation part away from the light source, and the refractive index of the fluorescence conversion part is less than the refractive index of the adjacent light-transmitting material layer.

[0013] By adopting the above technical solution, the refractive index of multiple light-transmitting material layers decreases in the direction away from the light source. When light propagates in the transparent encapsulation, it enters the less dense medium from the optically denser medium each time it passes through an interlayer interface. The refractive index difference between adjacent layers is small, reducing the reflection loss of light in the transparent encapsulation and allowing more light to pass through layer by layer, thus improving the light extraction efficiency. At the same time, the refractive index of the fluorescence conversion section is smaller than that of the adjacent light-transmitting material layers, continuing the gradient of decreasing refractive index from the inside to the outside. This also reduces interface reflection when light enters the fluorescence conversion section, avoiding reflection loss at the interface between the fluorescence conversion section and the light-transmitting material layer, further improving the overall light extraction efficiency.

[0014] Preferably, multiple light-transmitting material layers are stacked sequentially in a direction away from the light source, and any two adjacent light-transmitting material layers are bonded together to form an interlayer bonding surface; at each interlayer bonding surface, the side of the light-transmitting material layer closest to the light source that is away from the light source is recessed to form an interlayer cavity, and the side of the light-transmitting material layer away from the light source that faces the light source forms a protrusion that fits into the interlayer cavity.

[0015] By adopting the above technical solution, the interlocking structure of the interlayer cavity and the protrusion forms a three-dimensional interlock between adjacent light-transmitting material layers, which increases the interlayer shear resistance and suppresses interlayer slippage and delamination caused by the difference in thermal expansion coefficients. At the same time, the interlocking structure transforms the interlayer bonding surface from a plane to a three-dimensional curved surface, increasing the actual contact area between the two materials and improving the bonding strength. In addition, during the molding process, the molten light-transmitting material preferentially fills the bottom of the cavity and diffuses from the center to the edge, squeezing out the residual gas from the center to the edge. After solidification, it forms a protrusion in the cavity, avoiding the generation of interlayer bubbles.

[0016] Preferably, the interlayer bonding surface formed by the interlayer cavity and the protrusion is arc-shaped on a cross-section perpendicular to the substrate, and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints.

[0017] By adopting the above technical solution, the interlayer bonding surface formed by the interlayer concave cavity and the protrusion is an arc-shaped curved surface, which makes the light-transmitting material layer near the light source form a concave lens structure at this position, which has a diverging effect on the concentrated light emitted by the light source, expands the propagation angle of the light, and reduces the light intensity concentration in the central area. The design of the curvature gradually decreasing from the center to the edge makes the divergence effect stronger in the central area and weaker in the edge area, which is in line with the distribution characteristics of strong light intensity in the center of the light source and weak light intensity at the edge, so that the diverged light intensity tends to be uniform.

[0018] Preferably, the curvature of each interlayer bonding surface at its vertex on a cross section perpendicular to the substrate increases sequentially from the interlayer bonding surface closer to the light source to the interlayer bonding surface farther from the light source.

[0019] By adopting the above technical solution, all interlayer bonding surfaces are concave downwards, and the curvature of the central region of each interlayer bonding surface increases sequentially in the direction away from the light source. This causes each light-transmitting material layer to be affected by the combined action of its upper and lower bonding surfaces, forming a concave lens structure that is thin in the middle and thick at the edges within the layer. The closer the light-transmitting material layer is to the outer side, the greater the degree of concavity of its upper surface and the thinner the thickness of the central region within the layer, resulting in a stronger optical divergence capability of the concave lens. The upper layer further expands the divergence angle on this basis, and the synergistic effect of multiple layers gradually reduces the central intensity of the beam, thereby improving the uniformity of light output.

[0020] Preferably, the fluorescence conversion part is bonded to the light-transmitting material layer furthest from the light source; the light-transmitting material layer furthest from the light source has a recessed top cavity on the side facing away from the light source; the fluorescence conversion part has a conversion part protrusion that fits into the top cavity on the side facing the light source.

[0021] By adopting the above technical solution, the protrusion of the fluorescence conversion part is embedded in the top cavity of the outermost light-transmitting material layer, forming a three-dimensional interlocking structure between the fluorescence conversion part and the light-transmitting material layer. This increases the shear resistance between the two and suppresses interface slippage and delamination caused by the difference in thermal expansion coefficients between the fluorescence conversion part and the light-transmitting material layer. At the same time, the embedding of the protrusion of the conversion part with the top cavity transforms the interface from a plane to a three-dimensional curved surface, increasing the actual contact area between the fluorescence conversion part and the light-transmitting material layer and improving their bonding strength.

[0022] Preferably, the top-layer cavity and the transition portion protrusion cooperate to form a transition bonding surface; the transition bonding surface is arc-shaped on a cross-section perpendicular to the substrate, and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints; and the curvature of the transition bonding surface at the vertex on the cross-section perpendicular to the substrate is greater than the curvature of any interlayer bonding surface at the vertex on the cross-section perpendicular to the substrate.

[0023] By adopting the above technical solution, the conversion bonding surface is an arc-shaped surface with curvature decreasing from the center to the edge, so that the bottom surface of the fluorescence conversion part forms a concave lens shape at this position, which further diverges the light that has been diffused layer by layer in the previous sequence; and the curvature of the central region of the conversion bonding surface is greater than the curvature of the central region of any interlayer bonding surface, so that the degree of concavity of the bottom surface of the fluorescence conversion part is greater than the degree of concavity between each light-transmitting material layer, and the light divergence effect is stronger than that of each interlayer bonding surface, further reducing the light intensity concentration in the central region.

[0024] Preferably, the surface of the fluorescence conversion section away from the conversion bonding surface is formed with a light-emitting concave surface. The light-emitting concave surface is recessed in the direction close to the conversion bonding surface, and the curvature of the light-emitting concave surface at the vertex on the cross-section perpendicular to the substrate is greater than the curvature of the conversion bonding surface at the vertex on the cross-section perpendicular to the substrate.

[0025] By adopting the above technical solution, the curvature of the central region of the light-emitting concave surface is greater than that of the central region of the conversion bonding surface, making the top surface of the fluorescence conversion part more concave than the bottom surface. The two work together to form a concave lens structure in the fluorescence conversion part that is thin in the middle and thick at the edges, which further diverges the light. In addition, since the light intensity in the edge region is low and the amount of light converted is less, the thickness of the edge region is thicker, which prolongs the propagation path of the weak light at the edge, improves the conversion ratio in this region, and makes up for the conversion amount in the edge region.

[0026] A method for preparing a pyramid-shaped luminescent structure includes the following steps:

[0027] S1. Fix the light source onto the substrate and complete the electrical conduction;

[0028] S2. Preheat the mold to the molding temperature;

[0029] S3. Using a layered molding process, molten light-transmitting material with a progressively decreasing refractive index is injected into the mold cavity from the inside out and then solidified to construct the transparent encapsulation part that covers the light source;

[0030] S4. On the surface of the outermost light-transmitting material layer, a conversion material containing phosphor is injected into the mold cavity and cured to form the phosphor conversion part;

[0031] S5. Heat and solidify the overall structure, and then demold to obtain the finished product.

[0032] By adopting the above technical solutions, preheating the mold to the set molding temperature reduces the temperature gradient between the molten light-transmitting material and the mold, slowing down the rapid cooling rate of the material upon contact with the mold, and avoiding internal stress and surface micro-cracks caused by sudden cooling; the layered molding process injects materials with decreasing refractive index into the mold sequentially from the inside to the outside, so that each layer of material is formed after the previous layer has solidified, ensuring the control of the refractive index gradient between layers and avoiding the loss of control over the refractive index distribution caused by the difference in fluidity when multiple materials are injected into the mold at one time; the overall heating and curing and slow cooling treatment release the residual stress accumulated during the molding process, reducing the risk of deformation or cracking caused by stress release after demolding.

[0033] Preferably, in the layered molding process described in step S3, the forming process of two adjacent light-transmitting material layers includes:

[0034] S31. The light-transmitting material layer described above is molded and cured, and the interlayer cavity is pressed into the surface of the layer facing away from the light source by a mold;

[0035] S32. Inject the next layer of molten light-transmitting material into the mold to cover the previous light-transmitting material layer and the interlayer cavity;

[0036] S33. Applying pressure to the mold causes the molten material to diffuse from the center to the edge to expel air. After solidification, it forms a layered structure covering the next light-transmitting material layer. At the same time, the material filling the interlayer cavity solidifies to form the fitting protrusion. And while the mold is being pressed and solidified, a new interlayer cavity is pressed into the outer surface of the next light-transmitting material layer on the side away from the light source using a mold.

[0037] S34. Treat the next light-transmitting material layer with the new interlayer cavity as the previous light-transmitting material layer, and repeat steps S32 to S33 by sequentially replacing molds with different surface parameters, so that the formed interlayer bonding surface is arc-shaped on the cross-section perpendicular to the substrate, and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints. The curvature of each interlayer bonding surface at the vertex on the cross-section perpendicular to the substrate increases sequentially from the interlayer bonding surface near the light source to the interlayer bonding surface away from the light source.

[0038] By adopting the above technical solution, after the upper translucent material layer is cured, an interlayer cavity is pressed out, and then the next layer of molten material is injected for coating. This allows the lower layer of molten material to fit tightly with the upper cavity in a flowing state, eliminating microscopic gaps between layers. When the mold is closed and pressure is applied, the molten material diffuses from the center to the edge. Utilizing the flow characteristic of the molten material preferentially filling the bottom of the cavity, a directional flow from the center outward is formed, forcibly pushing the gas remaining between layers to the edge for discharge. After curing, a fitting protrusion is formed in the cavity, avoiding the retention of air bubbles. During the stacked injection molding, a new cavity for the next coating is simultaneously pressed out on its outer surface, forming a closed process cycle. By sequentially changing molds with different surface parameters and repeating the steps, the curvature of the interlayer bonding surface of each layer is controlled by the surface shape of the mold cavity, ensuring that the interlayer bonding surface forms a concave structure with a large central curvature and a small edge curvature.

[0039] Preferably, the process of forming the fluorescence conversion section in step S4 includes:

[0040] S41. When forming the outermost light-transmitting material layer in step S3, the top-layer cavity is pressed out on its surface using a mold;

[0041] S42. Inject the molten conversion material into the mold to cover the outermost light-transmitting material layer and the top cavity;

[0042] S43. After mold closing and pressure application, the main body of the fluorescent conversion part is formed after curing. At the same time, the material filling the top cavity is cured to form the conversion part protrusion that fits and fits.

[0043] S44. During the mold closing and pressure application process in step S43, the inward protruding structure at the top of the mold is used for downward pressure and shaping, so that the top surface of the fluorescence conversion part away from the light source is pressed and solidified to form the inwardly recessed light-emitting concave surface.

[0044] By adopting the above technical solution, the top-layer cavity is pressed out during the molding of the outermost light-transmitting material layer. Molten conversion material is then injected into the mold to cover it, allowing the conversion material to fill the top-layer cavity in a flowing state and adhere tightly to the outermost light-transmitting material layer, eliminating microscopic gaps between them and avoiding residual interface bubbles. During mold closing and pressure application, the inward-protruding structure at the top of the mold presses down on the top surface of the fluorescent conversion part. Its protruding central portion preferentially contacts the molten conversion material, forcing the material in the central area to flow towards the edge. This pushes residual gas in the center to the edge for discharge and forces the conversion material downwards into and fills the top-layer cavity, solidifying to form a conversion part protrusion that fits into the top-layer cavity, improving the bonding strength between the fluorescent conversion part and the light-transmitting material layer. Simultaneously, the material in the central area thins after being extruded, while the material in the edge area thickens after accumulation. Under mold closing and pressure holding, this solidifies to form a light-emitting concave surface that is thin in the middle and thick at the edges. This directly forms a concave lens structure through molding, reducing subsequent processing steps.

[0045] In summary, this application includes at least one of the following beneficial technical effects:

[0046] 1. The refractive index of multiple light-transmitting material layers decreases in the direction away from the light source. This ensures that when light propagates within the transparent encapsulation, it passes through an optically denser medium to an optically less dense medium at each interlayer interface. The refractive index difference between adjacent layers is small, avoiding strong reflections at the interlayer interfaces caused by abrupt changes in refractive index. This reduces reflection losses within the transparent encapsulation, allowing more light to pass through layer by layer and improving light extraction efficiency. Simultaneously, the refractive index of the phosphor conversion section is lower than that of the adjacent light-transmitting material layers, continuing the gradient of decreasing refractive index from the inside out. This also reduces interface reflections when light enters the phosphor conversion section, avoiding reflection losses at the interface between the phosphor conversion section and the light-transmitting material layers, further improving the overall light extraction efficiency.

[0047] 2. The interlocking structure of the interlayer cavity and the protrusion forms a three-dimensional interlock between adjacent light-transmitting material layers, increasing the interlayer shear resistance and suppressing interlayer slippage and delamination caused by the difference in thermal expansion coefficients. At the same time, the interlocking structure transforms the interlayer bonding surface from a plane to a three-dimensional curved surface, increasing the actual contact area between the two materials and improving the bonding strength. In addition, the molten light-transmitting material preferentially fills the bottom of the cavity during the molding process and diffuses from the center to the edge, squeezing out the residual gas from the center to the edge. After solidification, it forms a protrusion in the cavity, avoiding the generation of interlayer bubbles.

[0048] 3. All interlayer bonding surfaces are concave downwards, and the curvature of the central region of each interlayer bonding surface increases sequentially in the direction away from the light source. This causes each light-transmitting material layer to be affected by the combined action of its upper and lower bonding surfaces, forming a concave lens structure that is thin in the middle and thick at the edges within the layer. The closer the light-transmitting material layer is to the outer edge, the greater the degree of concavity of its upper surface and the thinner the thickness of the central region within the layer, resulting in a stronger optical divergence capability of the concave lens. This layer-by-layer enhanced divergence design allows the lower layer to initially diverge the light, while the upper layer further expands the divergence angle on this basis. The multi-layer progressive synergy reduces the central intensity of the beam and improves the uniformity of the emitted light.

[0049] 4. After the upper translucent material layer is cured, an interlayer cavity is pressed out. Then, the next layer of molten material is injected to cover it, so that the lower layer of molten material fits tightly with the upper cavity in a flowing state, eliminating the microscopic gaps between the layers. When the mold is closed and pressure is applied, the molten material diffuses from the center to the edge. Taking advantage of the flow characteristic of the molten material preferentially filling the bottom of the cavity, a directional flow from the center to the outside is formed, forcibly pushing the gas remaining in the interlayer to the edge for discharge. After curing, a matching protrusion is formed in the cavity, avoiding the sealing of air bubbles. When forming the outermost translucent material layer, the top layer cavity is pressed out. Then, the molten conversion material is injected into the mold to cover it, so that the conversion material fills the top layer cavity in a flowing state and fits tightly with the outermost translucent material layer, eliminating the microscopic gaps between the two and avoiding the residue of interface air bubbles. When the mold is closed and pressure is applied, the inward protrusion structure at the top of the mold presses down on the top surface of the fluorescent conversion part. Its protruding central part preferentially contacts the molten conversion material, forcing the material in the central area to flow towards the edge. On the one hand, it pushes the gas remaining in the center to the edge and discharges it. On the other hand, it squeezes the conversion material downward into the top cavity and fills it. It solidifies to form a conversion part protrusion that fits into the top cavity, which improves the bonding strength between the fluorescent conversion part and the light-transmitting material layer. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the pyramid-shaped light-emitting structure provided in Embodiment 1 of this application;

[0051] Figure 2 This is a cross-sectional view of the pyramid-shaped light-emitting structure provided in Embodiment 1 of this application;

[0052] Figure 3 This is a cross-sectional view of the pyramid-shaped light-emitting structure provided in Embodiment 2 of this application;

[0053] Figure 4 This is a cross-sectional view of the transparent encapsulation part in the disassembled state of Embodiment 2 of this application;

[0054] Explanation of reference numerals in the attached drawings: 1. Substrate; 2. Light source; 3. Light-emitting structure; 31. Transparent encapsulation part; 311. Light-transmitting material layer; 312. Interlayer cavity; 313. Protrusion; 314. Interlayer bonding surface; 315. Top layer cavity; 32. Fluorescence conversion part; 321. Conversion part protrusion; 322. Conversion bonding surface; 323. Light-emitting concave surface. Detailed Implementation

[0055] The following is in conjunction with the appendix Figures 1-4 This application will be described in further detail.

[0056] Example 1

[0057] Please see Figure 1 and Figure 2 The pyramid-shaped light-emitting structure provided in this application embodiment can be applied to products such as LED phototherapy devices, physiotherapy light sources, beauty light irradiation equipment, and medical auxiliary light irradiation devices. The structure includes a substrate 1, at least one light source 2, and at least one light-emitting structure 3. The light source 2 is fixed on the substrate 1, and the light-emitting structure 3 is arranged in a one-to-one correspondence with the light source 2. Each light-emitting structure 3 encapsulates its corresponding light source 2 and includes a transparent encapsulation part 31 and a fluorescence conversion part 32. This structure can effectively encapsulate the light source 2 and convert light. The substrate 1 can serve as a carrier substrate for fixing the light source 2 and enabling circuit conduction. The light source 2 can be selected using an LED chip with a corresponding emission wavelength according to the phototherapy application scenario and physiotherapy indications.

[0058] The transparent encapsulation section 31 includes multiple light-transmitting material layers 311. The light-transmitting material layers 311 are made of materials such as silicone. When using silicone as the light-transmitting material layer 311, a high-refractive-index silicone layer, a medium-refractive-index silicone layer, and a low-refractive-index silicone layer can be sequentially arranged from the inside out. The high-refractive-index silicone layer directly covers the light source 2, the medium-refractive-index silicone layer covers the outside of the high-refractive-index silicone layer, and the low-refractive-index silicone layer covers the outside of the medium-refractive-index silicone layer. The multiple light-transmitting material layers 311 are stacked sequentially in a direction away from the light source 2, and any two adjacent light-transmitting material layers 311 are bonded together.

[0059] The refractive index of the multiple light-transmitting material layers 311 decreases in the direction away from the light source 2. When light propagates within the transparent encapsulation part 31, it passes through the bonding interface between adjacent layers, moving from the optically denser medium to the optically less dense medium. The refractive index difference between adjacent layers is small, and the light does not experience strong reflection at the interlayer interface due to abrupt changes in refractive index. This reduces light reflection loss within the transparent encapsulation part 31, allowing more light to pass through layer by layer and improving light extraction efficiency. For example, the refractive index of the high-refractive-index silicone layer can be set to 1.65, the refractive index of the medium-refractive-index silicone layer can be set to 1.50, and the refractive index of the low-refractive-index silicone layer can be set to 1.38, decreasing progressively from the inside out.

[0060] The fluorescence conversion unit 32 is located on the side of the transparent encapsulation unit 31 away from the light source 2. The refractive index of the fluorescence conversion unit 32 is lower than that of the adjacent light-transmitting material layer 311. The fluorescence conversion unit 32 can be made of a conversion material containing phosphor, such as quantum dot phosphor, which is coated on the top and outer surface of the low-refractive-index silicone layer and integrated with the outer contour of the pyramid. The lower refractive index of the fluorescence conversion unit 32 compared to the adjacent light-transmitting material layer 311 maintains the gradient of decreasing refractive index from the inside to the outside. When light enters the fluorescence conversion unit 32 from the light-transmitting material layer 311, it also enters the less dense medium from the optically denser medium, reducing reflection loss at the interface between the fluorescence conversion unit 32 and the light-transmitting material layer 311 and further improving the overall light extraction efficiency. The original spectrum emitted by the light source 2 and the spectrum converted by the fluorescence conversion unit 32 combine to form a multi-band composite spectrum. Depending on the wavelength of the light source 2 and the type of phosphor, a composite spectrum suitable for different phototherapy, beauty, and medical applications can be formulated.

[0061] The light-emitting structure 3 is pyramid-shaped, and the pyramid-shaped light-emitting structure 3 is a regular square pyramid. The narrow outer contour is adapted to the light propagation path of the light emanating from the light source 2 in all directions, which reduces the incident angle of the light at the side wall of the light-emitting structure 3, avoids the loss of light being reflected back into the structure when the incident angle exceeds the critical angle of total internal reflection, and improves the emission efficiency of lateral light.

[0062] The implementation principle of this embodiment is as follows: The light source 2 is fixed on the substrate 1 and emits light. The emitted light enters each light-transmitting material layer 311, whose refractive index decreases layer by layer, from the inside to the outside. When the light passes through the interface between two adjacent light-transmitting material layers 311, it enters the light-transmitting material layer 311 with a lower refractive index from the light-transmitting material layer 311 with a higher refractive index, that is, from an optically denser medium to an optically less dense medium. The difference in refractive index between the two adjacent layers is small, and the amount of light reflected at the interface decreases accordingly, allowing most of the light to be transmitted into the outer layer. When the light reaches the interface between the outermost light-transmitting material layer 311 and the fluorescence conversion part 32, the refractive index of the fluorescence conversion part 32 is smaller than that of the adjacent light-transmitting material layer 311. The trend of decreasing refractive index continues to this interface, and the amount of light reflected here is also small, increasing the amount of light entering the fluorescence conversion part 32 from the transparent encapsulation part 31. After wavelength conversion is completed in the fluorescence conversion section 32, the light is emitted away from the substrate 1 along the gradually narrowing pyramid-shaped outer contour. The incident angle of the lateral light at the narrowing sidewall is smaller, and the light that is reflected back into the structure after crossing the critical angle of total internal reflection is reduced, allowing more lateral light to be emitted.

[0063] Example 2

[0064] Please see Figure 3 and Figure 4 The difference between this embodiment and the above embodiment is that, at each interlayer bonding surface 314, the light-transmitting material layer 311 near the light source 2 has a recessed cavity 312 on the side facing away from the light source 2, and the light-transmitting material layer 311 away from the light source 2 has a protrusion 313 that fits into the interlayer cavity 312. The interlocking structure of the interlayer cavity 312 and the protrusion 313 forms a three-dimensional interlock between adjacent light-transmitting material layers 311, increasing the interlayer shear resistance and suppressing interlayer slippage and delamination caused by the difference in thermal expansion coefficients; at the same time, the interlocking structure transforms the interlayer bonding surface 314 from a plane to a three-dimensional curved surface, increasing the actual contact area of ​​the two materials and improving the bonding strength; in addition, the molten light-transmitting material preferentially fills the bottom of the cavity during the molding process and diffuses from the center to the edge, squeezing out the residual gas from the center to the edge, and forming the protrusion 313 in the cavity after solidification, thus avoiding the generation of interlayer bubbles.

[0065] In this embodiment, the light-emitting structure 3 is generally conical. In this application, when the depth of the interlayer cavity is less than 0.05 mm, the interlocking effect of the interlocking structure is insufficient to resist the interlayer shear force; when the depth is greater than 0.3 mm, the cavity is too deep, resulting in the light-transmitting material layer being too thin at the bottom of the cavity, affecting optical uniformity. Therefore, the depth of the interlayer cavity 312 is 0.05-0.3 mm, the width is 60%-90% of the width of the interlayer bonding surface, and the depth-to-width ratio is 1:3 to 1:8. For example, when the total thickness of the light-transmitting material layer is 1 mm and the width of the interlayer cavity is 3 mm, when the cavity depth is 0.05 mm, the interlocking area is approximately X mm², and the measured shear strength is Y MPa; when the depth is 0.3 mm, the residual thickness at the bottom of the cavity is 0.7 mm, and stress concentration occurs at Z℃, leading to cracking.

[0066] The interlayer bonding surface 314 formed by the interlayer cavity 312 and the protrusion 313 is arc-shaped on the cross-section perpendicular to the substrate 1, and the radius of curvature of the arc increases from the apex to the two endpoints. This design causes the light-transmitting material layer 311 near the light source 2 to form a concave lens structure at this position, which diverges the concentrated light emitted by the light source 2, expands the propagation angle of the light, and reduces the light intensity concentration in the central region. The design of the radius of curvature increasing from the apex to the endpoints (i.e., the curvature decreasing from the apex to the endpoints) makes the divergence stronger at the apex and weaker at the endpoints, which, combined with the distribution characteristics of the light source 2 with strong light intensity at the center and weak light intensity at the edges, makes the diverged light intensity tend to be uniform. Furthermore, the curvature of each interlayer bonding surface 314 at the apex on the cross-section perpendicular to the substrate 1 increases sequentially from the interlayer bonding surface 314 near the light source 2 to the interlayer bonding surface 314 away from the light source 2.

[0067] All interlayer bonding surfaces 314 are concave downwards, and the curvature at the apex of each interlayer bonding surface 314 increases sequentially in the direction away from the light source 2. This causes each light-transmitting material layer 311 to be affected by the combined action of its upper and lower bonding surfaces, forming a concave lens structure that is thin in the middle and thick at the edges within the layer. The closer the light-transmitting material layer 311 is to the outer edge, the greater the degree of concavity of its upper surface and the thinner the thickness of the central region within the layer, resulting in a stronger optical divergence capability of the concave lens. This layer-by-layer enhanced divergence design allows the lower layer to initially diverge the light, while the upper layer further expands the divergence angle on this basis. The synergistic effect of multiple layers gradually reduces the central intensity of the beam, improving the uniformity of the emitted light.

[0068] The fluorescence conversion part 32 is bonded to the light-transmitting material layer 311 furthest from the light source 2. The side of the light-transmitting material layer 311 furthest from the light source 2 that faces away from the light source 2 is recessed to form a top-layer cavity 315. A conversion part protrusion 321, fitted into the top-layer cavity 315, is formed on the side of the fluorescence conversion part 32 facing the light source 2. This structure creates a three-dimensional interlocking structure between the fluorescence conversion part 32 and the light-transmitting material layer 311, increasing their shear resistance and suppressing interface slippage and delamination caused by the difference in thermal expansion coefficients between the fluorescence conversion part 32 and the light-transmitting material layer 311. Simultaneously, the fitting of the conversion part protrusion 321 with the top-layer cavity 315 transforms the interface from a planar surface to a three-dimensional curved surface, increasing the actual contact area between the fluorescence conversion part 32 and the light-transmitting material layer 311 and enhancing their bonding strength.

[0069] The top cavity 315 and the conversion part protrusion 321 cooperate to form a conversion bonding surface 322; the conversion bonding surface 322 is arc-shaped on the cross section perpendicular to the substrate 1, and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints; and the curvature of the conversion bonding surface 322 at the vertex on the cross section perpendicular to the substrate 1 is greater than the curvature of any interlayer bonding surface 314 at the vertex on the cross section perpendicular to the substrate 1, so that the degree of concavity of the bottom surface of the fluorescent conversion part 32 is greater than the degree of concavity between each light-transmitting material layer 311, and the light that has been diffused layer by layer in the previous sequence is diffused again.

[0070] A light-emitting concave surface 323 is formed on the surface of the fluorescence conversion section 32 facing away from the conversion bonding surface 322. The light-emitting concave surface 323 is recessed towards the conversion bonding surface 322, and the curvature of the light-emitting concave surface 323 at its vertex on the cross-section perpendicular to the substrate 1 is greater than the curvature of the conversion bonding surface 322 at its vertex on the cross-section perpendicular to the substrate 1. The curvature at the vertex of the light-emitting concave surface 323 is also greater than the curvature at the vertex of the conversion bonding surface 322, making the top surface of the fluorescence conversion section 32 more deeply recessed than the bottom surface. This results in the fluorescence conversion section 32 forming a concave lens structure that is thin in the middle and thick at the edges, which re-diversifies the light that has been diffused layer by layer in the previous sequence. The thickness of the central region of the fluorescence conversion section 32 is 0.2mm-1mm, and the thickness of the edge region is 0.5mm-2mm. Furthermore, since the edge region has less light intensity and therefore converts less light, the thicker edge region extends the propagation path of the weak light at the edge, increases the conversion ratio in this region, and compensates for the conversion amount in the edge region.

[0071] The implementation principle of this embodiment is as follows: When the light emitted by the light source 2 passes through the medium with progressively decreasing refractive index from the inside out, since each interlayer bonding surface 314 is an arc-shaped curved surface concave towards the light source 2, the light-transmitting material layer 311 near the light source 2 is in the shape of a concave lens at this position. The concentrated light emitted by the light source 2 is first diverged at the interlayer bonding surface 314 closest to the light source 2, and then passes through each interlayer bonding surface 314 with progressively increasing central curvature, and the divergence angle is gradually amplified. Since the curvature of each interlayer bonding surface 314 decreases from the central region to the edge region, the divergence degree of the central light is greater than that of the edge light. Corresponding to the distribution of strong central light and weak edge light of the light source 2, the central intensity of the beam is weakened layer by layer. After being diffused by the transparent encapsulation section 31, the light enters the fluorescence conversion section 32. The conversion bonding surface 322 on the bottom surface and the light-emitting concave surface 323 on the top surface of the fluorescence conversion section 32 are both concave inward, with the top surface being more concave, making it a concave lens shape that is thin in the middle and thick at the edges. The light is diffused again here. Because the edge area is thicker, the weak light has a longer propagation path in this area, and the amount of conversion with the phosphor is supplemented, ultimately forming a light spot with a small difference in light intensity between the center and the edge.

[0072] Example 3

[0073] The method for preparing the pyramid-shaped luminescent structure provided in this application includes the following steps:

[0074] S1. Fix the light source 2 onto the substrate 1 and complete the electrical conduction. In this step, firstly, a suitable substrate 1 must be selected. The substrate 1 can be a metal substrate or a ceramic substrate with good heat dissipation performance, etc. Then, fix the light source 2 onto the substrate 1 using methods such as soldering or bonding, ensuring a firm connection between the light source 2 and the substrate 1. Next, complete the electrical conduction of the light source 2 through wires, etc., so that the light source 2 can emit light normally. For example, a 450nm blue LED chip can be die-bonded onto a ceramic substrate, and gold wire bonding can be completed to obtain the LED chip substrate.

[0075] S2. Preheat the mold to the molding temperature. Preheating the mold can be done using heating rods or heating plates. Before preheating, clean the mold cavity of the molding equipment to ensure the inner wall of the cavity is clean and free of impurities. The purpose of preheating is to reduce the temperature gradient between the molten transparent material and the mold, slowing down the rapid cooling rate of the material upon contact with the mold, and avoiding internal stress and surface micro-cracks caused by sudden cooling. The mold preheating temperature is 100℃-150℃, preferably 120℃. When the temperature is below 100℃, the temperature gradient when the molten transparent material contacts the mold is too large, and the cooling rate exceeds 10℃ / s, resulting in internal stress exceeding 15MPa; when the temperature is above 150℃, the transparent material undergoes thermal degradation, and the refractive index deviation exceeds ±0.02.

[0076] In this application, the mold includes an upper mold and a lower mold. The size of the lower mold cavity increases with the number of molding layers to accommodate the solidified inner layer structure as an insert. The bottom surface of the upper mold is provided with a downwardly protruding curved pressure head, which is used to press the interlayer cavity 312 on the outer surface of the next light-transmitting material layer. The outer periphery of the curved pressure head is an annular plane or a gentle slope, which is used to control the outer contour shape of the next light-transmitting material layer.

[0077] S3. A layered molding process is used to sequentially inject and solidify molten light-transmitting materials with decreasing refractive index layer by layer from the inside out, constructing a transparent encapsulation part 31 covering the light source 2. The layered molding process involves injecting materials with decreasing refractive index from the inside out, with each layer solidified after the previous layer, avoiding the uncontrolled refractive index distribution caused by differences in flowability when injecting multiple materials at once, and ensuring control of the refractive index gradient between layers. The light-transmitting material can be silicone, with high-refractive-index silicone, medium-refractive-index silicone, and low-refractive-index silicone being sequentially molded and solidified to form the pyramid sidewalls layer by layer. The curing temperature of the high-refractive-index silicone layer is 100℃-120℃, and the curing time is 15min-25min; the curing temperature of the medium-refractive-index silicone layer is 90℃-110℃, and the curing time is 12min-20min; the curing temperature of the low-refractive-index silicone layer is 80℃-100℃, and the curing time is 10min-15min.

[0078] In the layered molding process, each layer is positioned in the lower mold cavity as an insert, along with the inner layer structure that has been cured in the previous step, along with the substrate 1 and the light source 2. This creates a cavity gap between the outer surface of the inner layer structure and the inner wall of the upper mold cavity, which is adapted to the thickness of the layer to be molded. Molten light-transmitting material is then injected, and the mold is closed and pressure is applied, so that the material is evenly covered and filled along the sides and top surface of the inner layer structure. After curing, the mold is opened and replaced with the next mold with an increasing cavity size. This process is repeated, forming layer by layer from the inside out.

[0079] Specifically, the forming process of the two adjacent light-transmitting material layers 311 includes:

[0080] S31. A light-transmitting material layer 311 is molded and cured, and an interlayer cavity 312 is pressed into its surface on the side facing away from the light source 2 using a mold. In this step, the substrate 1 and the light source 2 are positioned as inserts in the mold during the first execution. Molten light-transmitting material is injected into the mold, and the light-transmitting material is cured by applying certain pressure and temperature. At the same time, an interlayer cavity 312 is pressed into the surface of the light-transmitting material layer 311 using a special structure on the mold.

[0081] S32. After the inner layer is formed, the mold is opened and placed into another mold of the corresponding size to make the inner layer an insert. Then, the next layer of molten light-transmitting material is injected into the mold to cover the previous light-transmitting material layer 311 and the interlayer cavity 312. The injected molten light-transmitting material should have suitable fluidity to fully cover the previous light-transmitting material layer 311 and the interlayer cavity 312. After the previous light-transmitting material layer 311 has solidified and pressed out the interlayer cavity 312, the next layer of molten material is injected to cover it. The lower layer of molten material adheres to the upper cavity in a flowing state, reducing the microscopic gaps between the layers.

[0082] S33. Applying pressure during mold closing causes the molten material to diffuse from the center to the edge, expelling air. After solidification, it forms the layer covering structure of the next light-transmitting material layer 311. Simultaneously, the material filling the interlayer cavity 312 solidifies to form a fitting protrusion 313. Furthermore, due to the mold cavity structure, a new interlayer cavity 312 is simultaneously pressed onto the outer surface of the next light-transmitting material layer 311 on the side opposite to the light source 2 during this pressure application process. During mold closing and pressure application, pressure and time must be carefully controlled to ensure that the molten material can flow fully and expel air, forming a good fitting structure. During mold closing and pressure application, the molten material diffuses from the center to the edge, preferentially filling the bottom of the cavity, forming a directional flow from the center outwards. This pushes the gas remaining in the interlayer towards the edge for expulsion. After solidification, a fitting protrusion 313 is formed within the interlayer cavity 312, preventing air bubble retention.

[0083] S34. Treating the next light-transmitting material layer 311, which is wrapped around the outside and has a concave cavity, as the previous light-transmitting material layer 311 in subsequent processes, repeat steps S32 to S33 by sequentially changing molds with different surface parameters, so that the formed interlayer bonding surface 314 is arc-shaped on the cross-section perpendicular to the substrate 1. The radius of curvature of the arc increases from the vertex of the arc to the two endpoints. The curvature of each interlayer bonding surface 314 at the vertex on the cross-section perpendicular to the substrate 1 increases sequentially from the interlayer bonding surface 314 closer to the light source 2 to the interlayer bonding surface 314 farther away from the light source 2. By changing molds with different surface parameters, the curvature of the interlayer bonding surface 314 can be precisely controlled to achieve effective light divergence and uniform distribution. By controlling the curvature of the interlayer bonding surface 314 of each layer through the surface shape of the mold cavity, the interlayer bonding surface 314 forms a concave structure with a large vertex curvature and a small endpoint curvature.

[0084] S4. On the surface of the outermost transparent material layer 311, a conversion material containing phosphor is injected into the mold cavity and cured to form the phosphor conversion part 32. This integrates the phosphor with the pyramid structure. Specifically, the process of forming the phosphor conversion part 32 includes:

[0085] S41. In step S3, when forming the outermost light-transmitting material layer 311, a top-layer cavity 315 is pressed onto its surface using a mold. During the forming of the outermost light-transmitting material layer 311, a special structure on the mold is used to press out the top-layer cavity 315, preparing for the subsequent fitting of the fluorescence conversion part 32.

[0086] S42. Inject the molten conversion material into the mold, covering the outermost translucent material layer 311 and the top cavity 315. The injected molten conversion material should be able to fully fill the top cavity 315 and cover the outermost translucent material layer 311. The conversion material fills the top cavity 315 in a flowing state and adheres to the outermost translucent material layer 311, reducing the microscopic gaps between them.

[0087] S43. After mold closing and pressure application, the fluorescent conversion part 32 is formed as a main body after curing. At the same time, the material filling the top cavity 315 is cured to form a matching conversion part protrusion 321. During the mold closing and pressure application process, it is necessary to ensure that the conversion material can be fully cured and form a good fitting structure.

[0088] S44. During the mold closing and pressure application process in step S43, the inward protruding structure at the top of the mold is used for downward pressure and shaping, so that the top surface of the fluorescence conversion part 32 facing away from the light source 2 is pressed and solidified to form an inwardly recessed light-emitting concave surface 323. The inward protruding structure at the top of the mold can precisely control the shape and curvature of the light-emitting concave surface 323, so that the fluorescence conversion part 32 forms a concave lens structure that is thin in the middle and thick at the edges. The inwardly protruding structure at the top of the mold presses down on the top surface of the fluorescent conversion part 32. Its protruding central part first contacts the molten conversion material, forcing the material in the central area to flow towards the edge. On the one hand, it pushes the gas remaining in the center to the edge to be discharged, and on the other hand, it squeezes the conversion material downward into the top cavity 315 and fills it, solidifying to form a conversion part protrusion 321 that fits into the top cavity 315. After the material in the central area is squeezed out, the thickness decreases, and after the material in the edge area accumulates, the thickness increases. Under the pressure of mold closing, it solidifies to form a light-emitting concave surface 323 that is thin in the middle and thick at the edge, overcoming the tendency of the molten conversion material to form a convex surface that is thick in the middle and thin at the edge due to natural contraction of surface tension, thus forming a concave lens structure in one step.

[0089] S5. The overall structure is heated and cured, and the finished product is obtained after demolding. The heating and curing process can further enhance the bonding strength between the layers, resulting in a complete light-emitting structure after demolding. The overall heating and curing, along with slow cooling, releases the residual stress accumulated during the molding process, reducing the risk of deformation or cracking caused by stress release after demolding. For example, it can be cured at a constant temperature of 130℃ for 60 minutes, demolded after natural cooling, and the finished product is obtained after appearance and optical inspection.

[0090] The implementation principle of this embodiment is as follows: First, the light source 2 is welded or pasted onto the substrate 1 with heat dissipation performance and electrical conduction is completed. Then, the mold is preheated to the molding temperature, so that the temperature gradient between the subsequently injected molten light-transmitting material and the mold is reduced, the cooling rate of the material when it comes into contact with the mold is slowed down, and the internal stress and surface microcracks caused by sudden cooling are reduced accordingly.

[0091] After entering the layered molding process, the light-transmitting material with decreasing refractive index is injected into the mold and solidified layer by layer from the inside out: first, the upper light-transmitting material layer 311 is injected and solidified, and the mold is used to press out the interlayer cavity 312 on the side away from the light source 2; then, the next layer of molten light-transmitting material is injected to cover the upper layer and the cavity. Since the upper layer has been solidified, the lower molten material only adheres to the upper cavity in its own flow state, and the refractive indices of the two do not mix, so the interlayer refractive index gradient is maintained; when the mold is closed and pressure is applied, the molten material first fills the bottom of the cavity, and the material then diffuses from the center to the edge. The residual gas is pushed to the edge and discharged. After solidification, the material filling the interlayer cavity 312 forms a protrusion 313, which is embedded in the interlayer cavity 312 to form an interlocking structure. Each time a layer is formed, a mold with different surface parameters is used to repeat the above process. The curvature of the interlayer bonding surface 314 is determined by the surface shape of the mold cavity, so that each interlayer bonding surface 314 forms a concave surface with a large central curvature, a small edge curvature, and a central curvature that increases in the direction away from the light source 2.

[0092] When the outermost light-transmitting material layer 311 is formed, a top-layer cavity 315 is pressed out on its surface by a mold. Then, molten conversion material is injected to cover the outermost light-transmitting material layer 311 and the top-layer cavity 315, and the mold is closed and pressure is applied. During the pressure application process, the inward protruding structure at the top of the mold presses down on the top surface of the fluorescent conversion part 32. Its central part first contacts the molten conversion material, and the material in the central area is forced to flow towards the edge. On the one hand, it pushes the residual gas in the center to the edge to be discharged, and on the other hand, it squeezes the material downward into the top-layer cavity 315 and fills it. After solidification, it forms a conversion part protrusion 321 that fits into the top-layer cavity 315. After the material in the central area is squeezed out, the thickness decreases, and after the material in the edge area accumulates, the thickness increases. Under pressure, it solidifies into a light-emitting concave surface 323 that is thin in the middle and thick at the edge, which avoids the molten conversion material from naturally shrinking into a convex surface that is thick in the middle and thin at the edge under the action of surface tension.

[0093] Finally, the overall structure is heated and cured, and the bonding between each layer and the fluorescent conversion part 32 is further enhanced. The residual stress accumulated during the molding process is released with heating and slow cooling, and the light-emitting structure is obtained after demolding.

[0094] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Any other corresponding changes and modifications made based on the technical concept of this application should be included within the scope of protection of this application.

Claims

1. A pyramid-shaped luminescent structure, characterized in that, include: base(1); At least one light source (2) is fixed to the substrate (1); as well as At least one light-emitting structure (3) is provided in a one-to-one correspondence with the light source (2). Each light-emitting structure (3) covers the corresponding light source (2). Each light-emitting structure (3) includes a transparent encapsulation part (31) and a fluorescence conversion part (32). The light-emitting structure (3) as a whole gradually narrows from the substrate (1) toward the direction away from the substrate (1). The transparent encapsulation part (31) includes a plurality of light-transmitting material layers (311), and the refractive index of the plurality of light-transmitting material layers (311) decreases in the direction away from the light source (2); The fluorescence conversion part (32) is disposed on the side of the transparent encapsulation part (31) away from the light source (2), and the refractive index of the fluorescence conversion part (32) is less than the refractive index of the adjacent light-transmitting material layer (311).

2. The pyramid-shaped light-emitting structure according to claim 1, characterized in that, Multiple light-transmitting material layers (311) are stacked sequentially in a direction away from the light source (2), and any two adjacent light-transmitting material layers (311) are bonded together to form an interlayer bonding surface (314); at each interlayer bonding surface (314), the side of the light-transmitting material layer (311) closest to the light source (2) that is away from the light source (2) is recessed to form an interlayer cavity (312), and the side of the light-transmitting material layer (311) away from the light source (2) that faces the light source (2) forms a protrusion (313) that fits into the interlayer cavity (312).

3. The pyramid-shaped light-emitting structure according to claim 2, characterized in that, The interlayer bonding surface (314) formed by the interlayer cavity (312) and the protrusion (313) is arc-shaped on the cross section perpendicular to the substrate (1), and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints.

4. The pyramid-shaped light-emitting structure according to claim 3, characterized in that, The curvature of each interlayer bonding surface (314) at its vertex on a cross section perpendicular to the substrate (1) increases sequentially from the interlayer bonding surface (314) closer to the light source (2) to the interlayer bonding surface (314) farther away from the light source (2).

5. The pyramid-shaped light-emitting structure according to claim 2, characterized in that, The fluorescence conversion part (32) is bonded to the light-transmitting material layer (311) furthest from the light source (2); the light-transmitting material layer (311) furthest from the light source (2) has a recessed top cavity (315) on the side facing away from the light source (2); the fluorescence conversion part (32) has a conversion part protrusion (321) that fits into the top cavity (315) on the side facing the light source (2).

6. The pyramid-shaped light-emitting structure according to claim 5, characterized in that, The top-layer cavity (315) and the transition part protrusion (321) cooperate to form a transition bonding surface (322); the transition bonding surface (322) is arc-shaped on the cross-section perpendicular to the substrate (1), and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints; and the curvature of the transition bonding surface (322) at the vertex on the cross-section perpendicular to the substrate (1) is greater than the curvature of any interlayer bonding surface (314) at the vertex on the cross-section perpendicular to the substrate (1).

7. The pyramid-shaped light-emitting structure according to claim 6, characterized in that, The fluorescent conversion part (32) has a light-emitting concave surface (323) formed on the surface away from the conversion bonding surface (322). The light-emitting concave surface (323) is recessed in the direction close to the conversion bonding surface (322), and the curvature of the light-emitting concave surface (323) at the vertex on the cross section perpendicular to the substrate (1) is greater than the curvature of the conversion bonding surface (322) at the vertex on the cross section perpendicular to the substrate (1).

8. A method for preparing a pyramid luminescent structure, used to prepare the pyramid luminescent structure as described in claim 7, characterized in that, Includes the following steps: S1. Fix the light source (2) onto the substrate (1) and complete the electrical conduction; S2. Preheat the mold to the molding temperature; S3. Using a layered molding process, molten light-transmitting material with decreasing refractive index is injected into the mold cavity from the inside out and solidified to construct the transparent encapsulation part (31) covering the light source (2); S4. On the surface of the outermost light-transmitting material layer (311), a conversion material containing phosphor is injected into the mold cavity and cured to form the phosphor conversion part (32); S5. Heat and solidify the overall structure, and then demold to obtain the finished product.

9. The method for preparing the pyramid-shaped light-emitting structure according to claim 8, characterized in that, In the layered molding process described in step S3, the forming process of the two adjacent light-transmitting material layers (311) includes: S31. The light-transmitting material layer (311) is molded and cured, and the interlayer cavity (312) is pressed out on the side of the material facing away from the light source (2) by a mold. S32. Inject the next layer of molten light-transmitting material into the mold to cover the previous light-transmitting material layer (311) and the interlayer cavity (312); S33. Apply pressure to the mold to allow the molten material to diffuse from the center to the edge to expel air. After solidification, it forms the layer covering structure of the next light-transmitting material layer (311). At the same time, the material filling the interlayer cavity (312) solidifies to form the fitting protrusion (313). And while the mold is being pressed and solidified, a new interlayer cavity (312) is pressed out on the outer surface of the next light-transmitting material layer (311) on the side away from the light source (2) by the mold. S34. Treat the next light-transmitting material layer (311) with the new interlayer cavity as the previous light-transmitting material layer (311), and repeat steps S32 to S33 by changing molds with different surface parameters in sequence, so that the formed interlayer bonding surface (314) is arc-shaped on the cross section perpendicular to the substrate (1), and the radius of curvature of the arc increases from the vertex of the arc to the two endpoints. The curvature of each interlayer bonding surface (314) at the vertex on the cross section perpendicular to the substrate (1) increases sequentially from the interlayer bonding surface (314) near the light source (2) to the interlayer bonding surface (314) away from the light source (2).

10. The method for preparing the pyramid-shaped light-emitting structure according to claim 8, characterized in that, The process of forming the fluorescence conversion section (32) in step S4 includes: S41. When forming the outermost light-transmitting material layer (311) in step S3, the top cavity (315) is pressed out on its surface by a mold; S42. The molten conversion material is injected into the mold to cover the outermost light-transmitting material layer (311) and the top cavity (315); S43. After the mold is closed and pressure is applied, the main body of the fluorescent conversion part (32) is formed after curing. At the same time, the material filled in the top cavity (315) is cured to form the conversion part protrusion (321) that fits and fits. S44. During the mold closing and pressure application process in step S43, the inward protruding structure at the top of the mold is used for downward pressure and shaping, so that the top surface of the fluorescence conversion part (32) away from the light source (2) is pressed and solidified to form the inwardly recessed light-emitting concave surface (323).

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