A polycrystalline light source

Abstract

This utility model provides a polycrystalline light source, comprising: a triangular-shaped polycrystalline light source with multiple LED chips facing the same direction regularly arranged within the triangular area; each LED chip including a chip electrode, a light-emitting upper surface, and a light-emitting side surface; a first light conversion layer formed on the light-emitting side surface of each LED chip, the upper and side surfaces of an internal light-emitting layer, and the gap between each LED chip and the internal light-emitting layer; a first cladding layer formed at least on the side surface of the first light conversion layer; and a top light-emitting layer formed at least on the upper surface of the first light conversion layer. The top light-emitting layer uniformly distributes light, eliminating bright spots; and by setting the polycrystalline light source in a triangular shape, it can be flexibly applied to irregular and special spaces according to actual needs.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a polycrystalline light source. Background Technology

[0002] Currently, LED surface light sources are widely used in many fields such as lighting, display, and backlighting. However, in actual product applications, there is a problem of pixelation in the light source. LED surface light sources mainly achieve a large-area light emission effect by arranging multiple LED chips in an orderly manner. However, because the luminous flux density directly above a single chip is 3-5 times higher than that of the surrounding area, discrete bright spots are formed. When the chips are arranged in an array, obvious point-like light emission characteristics are formed, i.e., the pixelation phenomenon of the light source.

[0003] In practical applications, the graininess of light sources causes numerous adverse effects. For example, when LED surface light sources are used in lighting scenarios, they result in uneven light and shadow effects on the surface of illuminated objects, affecting visual comfort and reducing lighting quality. When used in display and backlighting, the graininess makes the image display less delicate and smooth, causing display distortion and severely impacting the user's viewing experience, making it difficult to meet the stringent light quality requirements of high-end display and lighting scenarios. Although some manufacturers in the industry have improved light uniformity by adding optical lenses or light diffusers, the thickness of these lenses or diffusers increases the overall thickness of the product, contradicting the current trend towards thinner and lighter automotive lights. Therefore, a more effective solution is needed to address the graininess problem of LED surface light sources. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a polycrystalline light source, which can effectively solve the technical problems of existing LED light sources being difficult to adapt to irregular spaces and having a grainy luminous effect.

[0005] The technical solution provided by this utility model is as follows:

[0006] This utility model provides a polycrystalline light source, comprising:

[0007] The polycrystalline light source is triangular, with multiple LED chips facing the same direction arranged regularly within the triangular area. Each LED chip includes a chip electrode, a light-emitting upper surface, and a light-emitting side surface.

[0008] The first light conversion layer is formed on the light-emitting side of each LED chip, the upper and side surfaces of the internal light-emitting layer, and the gap between each LED chip and the internal light-emitting layer.

[0009] A first coating layer is formed at least on the side of the first light conversion layer;

[0010] The top light-emitting layer is formed at least on the upper surface of the first light conversion layer.

[0011] The polycrystalline light source provided by this utility model has at least the following beneficial effects:

[0012] 1) In the packaging structure of a polycrystalline light source, the phosphor filling between and above each LED chip not only converts the light emitted by the LED into white light, but also has a certain diffusion effect on the light. During the conversion into white light, the light is continuously scattered secondary, tertiary, or even more times by the phosphor particles in the first light conversion layer; at the same time, a top light-emitting layer is formed on the upper surface of the first light conversion layer, which evenly scatters the light directly above each chip to all directions, breaking the state of light concentration above the chip; effectively eliminating the graininess caused by the high light density above each LED chip in the light source.

[0013] 2) By configuring the polycrystalline light source in a triangle, compared with the conventional circular or square design, it can be flexibly combined and applied in irregular special spaces according to actual needs, and cleverly embedded in various complex shapes and structures, such as door interior panels, center consoles, etc., solving the problem of installation compatibility of conventional designs in scenarios such as automotive ambient lighting and irregularly shaped displays. Attached Figure Description

[0014] Figure 1 This is a cross-sectional schematic diagram of a polycrystalline light source in one embodiment of the present invention;

[0015] Figure 2 for Figure 1 The bottom view of the polycrystalline light source shown;

[0016] Figure 3 This is a cross-sectional schematic diagram of a polycrystalline light source in one embodiment of the present invention, showing that the first coating layer height covers the first light conversion layer and the top light-emitting layer.

[0017] Figure 4 This is a cross-sectional schematic diagram of a polycrystalline light source with a second coating layer formed in one embodiment of the present invention;

[0018] Figure 5 This is a cross-sectional schematic diagram of a polycrystalline light source in another embodiment of the present invention;

[0019] Figure 6 This diagram illustrates the light-emitting effects of a traditional polycrystalline light source and a polycrystalline light source in one embodiment of this invention; wherein, Figure 6 (a) is a diagram showing the light emission effect of a traditional polycrystalline light source. Figure 6 (b) is a diagram showing the light emission effect of a polycrystalline light source according to an embodiment of the present invention.

[0020] Figure label:

[0021] 10-LED chip, 11-Light-emitting upper surface, 12-Chip electrode, 20-Internal light-emitting layer, 30-First light conversion layer, 31-Second light conversion layer, 40-First coating layer, 41-Second coating layer, 50-Top light-emitting layer, 100-Polycrystalline light source. Detailed Implementation

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0023] One embodiment of this utility model discloses a polycrystalline light source, comprising: the polycrystalline light source being triangular, with multiple LED chips facing the same direction regularly arranged within the triangular region; each LED chip including a chip electrode, a light-emitting upper surface, and a light-emitting side surface; a first light conversion layer formed on the light-emitting side surface of each LED chip, the upper surface and side surface of an internal light-emitting layer, and the gap between each LED chip and the internal light-emitting layer; a first coating layer formed at least on the side surface of the first light conversion layer; and a top light-emitting layer formed at least on the upper surface of the first light conversion layer.

[0024] In this embodiment, the LED chip is a flip-chip, having a light-emitting upper surface, a light-emitting side surface, and chip electrodes formed on the surface opposite to the light-emitting upper surface. The chip electrode material can be copper pillars, etc., with both positive and negative electrodes on the surface opposite to the light-emitting upper surface. Each LED chip's internal epitaxial structure contains at least an n-type layer, an active layer, and a p-type layer. When current is passed through the chip electrodes, the active layer emits light of a specific color. Depending on actual needs, the internal epitaxial structure may vary, and the emitted color can be blue, red, or yellow, etc. This embodiment does not impose any restrictions, as long as it emits light normally after applying an appropriate voltage. The light-emitting upper surface of the LED chip is generally square, but can also be circular, polygonal, etc. The chip size can be determined according to actual power requirements. For example, for square chips, the chip side length is generally 10mil-65mil. High-power chips require a larger chip area to distribute current and prevent localized overheating.

[0025] In this embodiment, the polycrystalline light source contains multiple LED chips, all of which are flip-chip structures. The electrodes of each LED chip in the light source face the same direction, and the electrode surfaces are exposed for easy subsequent surface mounting. The polycrystalline light source is triangular, and the specific shape and size of the triangular region can be designed according to the requirements of the application scenario. To meet the installation requirements of narrow or irregular spaces, it can be designed as an equilateral triangle, isosceles triangle, right triangle, oblique triangle, etc., with sizes ranging from a few millimeters to tens of millimeters. Those skilled in the art can design it according to the actual application scenario, and this embodiment does not impose any limitations on this.

[0026] Polycrystalline light sources consist of chip positions arranged regularly within triangular regions. Each chip position contains at least one LED chip. The chip positions are distributed in an array around the geometric center of the triangle, meaning the center of the pattern of all chip positions coincides with the center of the triangle, and the spacing between all adjacent LED chips should be approximately consistent, arranged according to strict geometric rules. Each chip position can have one or more LED chips. The number of LED chips in a polycrystalline light source can be several or even dozens. When a single chip position contains one LED chip, all LED chips are distributed in an array around the geometric center of the triangle on the overall spatial surface of the polycrystalline light source. This regular arrangement allows the light emitted by the LED chips to be uniformly superimposed in space, avoiding brightness fluctuations caused by differences in local chip density. At the same time, to avoid dark areas, the spacing between adjacent LED chips cannot be too large. The specific spacing limit depends on the type of LED chip used; higher power LED chips can have a wider spacing. Figure 1 and Figure 2 In the example shown, the polycrystalline light source 100 is an equilateral triangle with a side length L of 10 mm. Six chip positions are regularly arranged inside. Within the triangular area, based on the center of the triangle, they are arranged in three rows from bottom to top, with a row spacing b of 1.83 mm. The upper and lower rows are arranged alternately. The first row has three chip positions arranged along one side of the equilateral triangle, the second row has two chip positions, and the third row has one chip position. The distance a between adjacent chip positions within the same row is 1.69 mm. Chip positions near the edge are also at a certain distance from the edge of the polycrystalline light source, such as... Figure 2As shown, the shortest straight-line distance c (i.e., the straight-line distance perpendicular to the side length) between the chip position at the lower right corner and the side of the triangle is 1.04 mm. One LED chip is die-bonded at each chip position, and six flip-chip LEDs 10 are evenly distributed within the triangular area. The LED chip 10 used in this polycrystalline light source has a size of 13 mil * 32 mil. Experimental results show that dark areas easily appear when the spacing between chips exceeds 2500 μm. When using other arrangement methods for the chips, it should be noted that the spacing between adjacent LED chips should be less than 2500 μm. When the LED chips are arranged in an array, the spacing referred to here includes... Figure 2 The column spacing 'a' and row spacing 'b' referred to in the text are both less than 2500 μm.

[0027] In another example, multiple LED chips are die-bonded at a single chip location. Different LED chips at the same chip location can have the same light color or different light colors, such as die-bonding a red light chip, a green light chip, and a blue light chip at one chip location.

[0028] The first light conversion layer contains phosphor, which converts transmitted light into another wavelength. The phosphor is a phosphor that can be excited by the light emitted by the LED chip, thereby converting the light emitted by the LED chip into the desired color. The phosphor can be at least one or more of the following: garnet phosphor, oxynitride phosphor, aluminate phosphor, nitride phosphor, sulfide phosphor, KSF phosphor, etc. The first light conversion layer completely covers the light-emitting side and the light-emitting top surface of each LED chip, and also has a certain height above the light-emitting top surface. Theoretically, the height of the first light conversion layer above the light-emitting top surface is the same as the width on the side of the LED chip, so that the light emitted by the LED chip enters the upper and surrounding first light conversion layers, and after being excited to the same degree, is converted into the same color. In practical applications, even if there is a slight difference in the height of the first light conversion layer above the internal light-emitting layer and its width on the side of the LED chip, it will not affect the overall light color. The difference is only a minor adjustment in color temperature. That is, the color temperature parameter of the polycrystalline light source can be adjusted by the thickness of the first light conversion layer: with the phosphor ratio remaining constant, appropriately increasing the thickness of the first light conversion layer lowers the color temperature; conversely, the thinner the layer, the higher the color temperature. The first light conversion layer completely covers the side and upper surface of the LED chip. The phosphor within it not only converts the blue light emitted by the LED chip into white light but also has a certain light diffusion effect. In particular, when the light emitted by the LED chip enters the first light conversion layer, during the conversion to white light, the light is further scattered secondary, tertiary, or even more times by the phosphor particles in the first light conversion layer, improving the light emission uniformity of the polycrystalline light source.

[0029] The top light-emitting layer is formed on the upper surface of the first light conversion layer, covering it. It is semi-transparent in appearance and contains reflective materials. Without sacrificing the brightness of the polycrystalline light source, it also has a certain diffusion effect. This allows the light from the polycrystalline light source, after being converted to the desired color by the first light conversion layer, to be further diffused by the top light-emitting layer before being emitted. This effectively eliminates the graininess caused by the high light density above each LED chip in the polycrystalline light source. In other words, when the polycrystalline light source is lit, the light output is uniform, and the bright spots of the chips are almost invisible to the naked eye. The top light-emitting layer is a mixture of silicone or resin and reflective materials. The resin can be epoxy resin, thermosetting polyimide resin, phenolic resin, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, thermosetting polyurethane resin, etc., preferably thermosetting silicone resin or epoxy resin. Reflective materials are generally white inorganic pigments, such as oxides like titanium dioxide, zinc oxide, and zirconium oxide; carbonates like lead white (lead carbonate) and calcium carbonate; and clay minerals like kaolinite. Titanium dioxide is preferred. Mixtures of these materials can also be used, with different proportions to create a reflective material combination best suited for specific applications. In one example, the top light-emitting layer is prepared by mixing silica gel with TiO2 and SiO2, with a mass ratio of silica gel:TiO2:SiO2 of 1:(0.01-0.05):(0.6-1.5); and a thickness of 1000μm-1500μm. Notably, the top light-emitting layer employs a relatively thick structure, providing ample space for optical manipulation. For LED chips of varying power and package specifications on the market, significant scattering effects can be achieved simply by fine-tuning the doping ratio of the reflective material, without adjusting the overall structure of the polycrystalline light source. For high-power chips, the proportion of reflective material is appropriately increased to enhance light scattering intensity and balance the concentrated light spot caused by high brightness; for low-power chips, the doping ratio is reduced to decrease light loss and ensure overall luminous flux. This makes the top light-emitting layer compatible with various mainstream LED chips currently on the market, greatly improving the product compatibility and application range of the polycrystalline light source.

[0030] Since flip-chip LEDs emit light from five sides, and the illuminance above the upper surface of a typical LED chip is much greater than the illuminance around the chip, the illuminance directly above a single chip can be excessive. In this embodiment, the purpose of the top light-emitting layer is to ensure that the light emission effect directly above the LED chip is consistent with the surrounding area, allowing some light from the upper surface to be evenly scattered in all directions, avoiding the appearance of granular bright spots. Therefore, the doping ratio of the reflective material in the top light-emitting layer needs to be precisely controlled; it cannot be too high or too low. If the doping ratio is too high, the light will be completely blocked, resulting in no light or weak light directly above the LED chip. If the doping ratio is too low, the light cannot be sufficiently scattered, and the problem of excessively high luminous flux density directly above the chip cannot be effectively solved. The same applies to the thickness of the top light-emitting layer; if the thickness is too large, it will block the light, and if the thickness is too small, it will not form effective scattering. Since the ultimate goal is to ensure uniform light emission from the polycrystalline light source, in practical applications, the doping ratio, thickness, and other parameters of the reflective material in the top light-emitting layer are closely related not only to the power and size of the LED chip but also to the spacing between the LED chips. The light emitted by different LED chips will propagate and superimpose between the chips, which will affect the light scattering effect of the internal light-emitting layer. Specifically, it should be considered in combination with the light emission of the LED chips and the gap between adjacent LED chips.

[0031] The first coating layer surrounds the first light conversion layer, and the surface of the first coating layer away from the LED chip electrode is no lower than the surface of the first light conversion layer away from the LED chip electrode. It serves to reflect light from the side, ensuring that the light from the entire polycrystalline light source is emitted only from the surface of the top light-emitting layer. To ensure that no light from the light source leaks out, the thickness of the high-reflectivity white adhesive must be 250μm-500μm, meaning the distance between the inner wall (the surface near the first light conversion layer) and the outer wall (the surface exposed to the external environment) of the first coating layer must be 250μm-500μm.

[0032] The positions of the first cladding layer and the top light-emitting layer can be determined as follows: Figure 1 As shown, the top light-emitting layer 50 covers the upper surface of the first light conversion layer 30 and the upper surface of the first covering layer 40. Alternatively, it can be arranged as follows: Figure 3 As shown, the first covering layer 40 completely covers the sides of the first light conversion layer 30 and the sides of the top light-emitting layer 50.

[0033] The space around the electrodes of an LED chip can be filled with either phosphor or reflective white adhesive; in one example, such as Figure 1 and Figure 2 ( Figure 2 for Figure 1 The bottom view of the polycrystalline light source shown), and Figure 3As shown in the polycrystalline light source, the space around the chip electrode 12 of the LED chip 10 is filled with phosphor adhesive. That is, the sides of the chip electrode 12, the light-emitting side, and the surface and sides of the internal light-emitting layer 20 of the LED chip 10 are all wrapped with phosphor adhesive. A second light conversion layer 31 is formed on the lower surface of the first light conversion layer 30, covering the sides of the chip electrode. Another example is... Figure 4 As shown, the space around the chip electrode 12 of the LED chip 10 is filled with reflective white glue, and the light-emitting side of the LED chip 10 and the surface and sides of the internal light-emitting layer 20 are wrapped with phosphor glue. That is, a second coating layer 41 is formed on the lower surface of the first light conversion layer 30, covering the side of the chip electrode. Relative to... Figure 1 In the example shown, the reflective white adhesive around the chip electrode can further reflect the light emitted towards the chip electrode side back, thereby improving the light emission efficiency of the polycrystalline light source.

[0034] The above embodiment is further improved to obtain this embodiment. In the polycrystalline light source of this embodiment, an internal light-emitting layer is also formed on the light-emitting surface of each LED chip, and the internal light-emitting layers corresponding to each LED chip are independent of each other.

[0035] In other words, in this embodiment, in addition to forming a top light-emitting layer on the upper surface of the first light conversion layer, the polycrystalline light source also further comprises an internal light-emitting layer on the light-emitting upper surface of the LED chip. The internal light-emitting layer and the top light-emitting layer work together. The internal light-emitting layer is mainly used to break the concentration of light emitted by the LED chip at the top, while the top light-emitting layer further homogenizes the light distribution before the light from the polycrystalline light source is emitted to the outside. This ensures that the light from the LED chip is uniformly diffused within the polycrystalline light source, avoiding the appearance of granular bright spots and guaranteeing uniform light emission from the light-emitting surface of the polycrystalline light source. Compared to the previous embodiment, the effect of eliminating bright spots is better. In this embodiment, the internal light-emitting layer covers the light-emitting upper surface of each flip-chip LED, and the coverage area is at least the same as the shape and size of the light-emitting upper surface, which can completely cover the light-emitting upper surface or be slightly larger than the area of ​​the light-emitting upper surface. Furthermore, the internal light-emitting layer is doped with a certain proportion of reflective material to improve the light emission uniformity of the polycrystalline light source.

[0036] One example Figure 5As shown, the polycrystalline light source contains both an internal light-emitting layer and a top light-emitting layer. In this case, the upper surface 11 of each LED chip 10 within the polycrystalline light source is provided with an internal light-emitting layer 20. The height of the first light conversion layer 30 completely covers the light-emitting side of each LED chip, and also covers the upper and side surfaces of the internal light-emitting layer 20, while also having a certain height above the internal light-emitting layer. Below the first light conversion layer, a second cladding layer 41 is also provided around the chip electrode 12. The first cladding layer 40 is provided on the sidewalls of the first light conversion layer and the second cladding layer of the polycrystalline light source, and the upper surface of the first light conversion layer covers the top light-emitting layer 50.

[0037] This polycrystalline light source can be directly mounted onto the corresponding driver substrate in a single application, eliminating the need for individual LED chip mounting. Furthermore, the entire polycrystalline light source utilizes a dual-layer optical design—an internal light-emitting layer and a top light-emitting layer—to effectively eliminate the graininess caused by the high light density above each LED chip, resulting in uniform and soft light emission. Figure 6 As shown, on the left Figure 6 (a) is a top view of the light emission effect of a traditional polycrystalline light source, which contains four LED chips. The light directly above each LED chip is stronger than the surrounding area, exhibiting a distinct granular light emission characteristic. (The image on the right side...) Figure 6 (b) is a top view of the light emission effect of the polycrystalline light source in this embodiment, showing uniform overall light emission.

[0038] At this point, theoretically, the height of the first light conversion layer above the inner light-emitting layer is the same as its width on the side of the LED chip. This ensures that the light emitted by the LED chip is fully scattered by the inner light-emitting layer, and the light from above and around the edges enters the first light conversion layer above the inner light-emitting layer and the first light conversion layer around the edges, respectively. After being excited to the same degree, they are converted into the same color of light. The first light conversion layer completely encloses the side of the LED chip and the inner light-emitting layer. The phosphor in it not only converts the blue light emitted by the LED chip into white light, but also has a certain diffusion effect on the light. In particular, the light emitted from above the LED chip enters the first light conversion layer after passing through the inner light-emitting layer. During the conversion into white light, the light is further scattered secondaryly, tertiarily, or even more times by the phosphor particles in the first light conversion layer, improving the light emission uniformity of the polycrystalline light source.

[0039] The internal light-emitting layer, the top light-emitting layer, the first coating layer, and the second coating layer are all doped with reflective materials, which are mixtures of silicone or resin and reflective materials. The resin can be epoxy resin, thermosetting polyimide resin, phenolic resin, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, thermosetting polyurethane resin, etc., preferably thermosetting silicone resin or epoxy resin. The reflective material is generally a white inorganic pigment, such as oxides like titanium dioxide, zinc oxide, and zirconium oxide, lead white (lead carbonate), calcium carbonate, clay minerals like kaolinite, etc., preferably titanium dioxide. It can also be a mixture of the above materials, using different proportions to formulate a reflective material combination best suited for specific applications. Since the internal light-emitting layer, the top light-emitting layer, the first cladding layer and the second cladding layer have different functions in the polycrystalline light source, the reflective materials and concentrations doped inside also differ. The first cladding layer and the second cladding layer are used to reflect side light emission and bottom light emission, respectively, and generally require a reflectivity of over 99%, with a doping ratio much higher than that of the internal light-emitting layer and the top light-emitting layer.

[0040] Regarding the doping ratio of the internal and top light-emitting layers, the goal is simply for them to work together to ensure uniform diffusion of light from the LED chip within the polycrystalline light source, avoiding granular bright spots and ensuring uniform light emission from the emitting surface. The thickness of the internal light-emitting layer is less than that of the top light-emitting layer. In one example, the internal light-emitting layer is used to scatter the light density directly above the LED chip; the top light-emitting layer is used to improve the surface appearance and color of the LED chip, enhancing color consistency. The doping ratio of reflective material in the internal light-emitting layer is greater than that in the top light-emitting layer. Both the internal and top light-emitting layers contain a mixture of SiO2 and TiO2. TiO2 particles have strong reflective properties and primarily function as scatterers, while SiO2 has high dispersibility, allowing for uniform distribution within the material. This effectively prevents particle aggregation of reflective material, reduces sedimentation due to gravity, and ensures uniform dispersion of the reflective material within the internal light-emitting layer, while also providing some scattering effect. The doping ratio varies depending on the different functional requirements of each layer, ensuring both anti-settling effects and assisting in light scattering, which helps improve luminous flux utilization and control light intensity fluctuations. The inner light-emitting layer is prepared by mixing silica gel with TiO2 and SiO2, with a mass ratio of silica gel:TiO2:SiO2 of 1:(0.05-0.2):(0.6-1.5); and a thickness of 80μm-120μm. The top light-emitting layer is also prepared by mixing silica gel with TiO2 and SiO2, with a mass ratio of silica gel:TiO2:SiO2 of 1:(0.01-0.03):(0.6-1.5); and a thickness of 1000μm-1500μm.

[0041] In another example, the doping ratio of reflective material in the inner light-emitting layer is lower than that in the top light-emitting layer. In this case, the top light-emitting layer is the primary scattering layer for the LED chip. The inner light-emitting layer is prepared by mixing silicone with TiO2 and SiO2, with a mass ratio of silicone:TiO2:SiO2 of 1:(0.005-0.03):(0.6-1.5); and a thickness of 40μm-120μm. The top light-emitting layer is also prepared by mixing silicone with TiO2 and SiO2, with a mass ratio of silicone:TiO2:SiO2 of 1:(0.01-0.05):(0.6-1.5); and a thickness of 1000μm-1500μm.

[0042] All the aforementioned polycrystalline light sources are fabricated using CSP packaging technology. During the fabrication process, an internal light-emitting layer is first formed on the upper surface of each LED chip. The thickness, particle size, and content of this internal light-emitting layer are carefully designed to ensure effective light scattering without excessively blocking light directly above the chip. Next, the LED chips with the internal light-emitting layers are arranged according to a predetermined triangular region. Phosphor adhesive / reflective white adhesive is injected to obtain a second light conversion layer / second coating layer. Then, phosphor adhesive is injected and cured to obtain a first light conversion layer. Next, grooves are cut along the edges of the triangular region to prepare the first coating layer. Any portion of the first coating layer exceeding the height of the first light conversion layer needs to be ground off. Finally, a top light-emitting layer is prepared on the surface of the first light conversion layer, and the edges of adjacent triangular regions are cut to obtain the polycrystalline light source.

[0043] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this utility model. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A polycrystalline light source, characterized in that include: The polycrystalline light source is triangular, with multiple LED chips facing the same direction arranged regularly within the triangular area. Each LED chip includes a chip electrode, a light-emitting upper surface, and a light-emitting side surface. The first light conversion layer is formed on the light-emitting side of each LED chip, the upper and side surfaces of the internal light-emitting layer, and the gap between each LED chip and the internal light-emitting layer. A first coating layer is formed at least on the side of the first light conversion layer; The top light-emitting layer is formed at least on the upper surface of the first light conversion layer.

2. The polycrystalline light source as described in claim 1, characterized in that, The polycrystalline light source includes chip positions arranged regularly in a triangular region, and at least one LED chip is die-bonded in each chip position.

3. The polycrystalline light source of claim 1 or 2, wherein, The thickness of the top light-emitting layer is 1000μm-1500μm.

4. The polycrystalline light source of claim 1 or 2, wherein, The top light-emitting layer is formed on the upper surface of the first light conversion layer and the upper surface of the first coating layer.

5. The polycrystalline light source of claim 1 or 2, wherein, The first coating layer is formed on the side of the first light conversion layer and the side of the top light-emitting layer.

6. The polycrystalline light source as described in claim 3, characterized in that, The polycrystalline light source further includes a second light conversion layer, formed on the lower surface of the first light conversion layer, covering the side of the chip electrodes; or The polycrystalline light source also includes a second coating layer, which is formed on the lower surface of the first light conversion layer and covers the side of the chip electrode.

7. The polychromatic light source of claim 6, wherein, An internal light-emitting layer is formed on the light-emitting surface of each LED chip, and the internal light-emitting layers corresponding to each LED chip are independent of each other.

8. The polycrystalline light source as described in claim 7, characterized in that, The thickness of the inner light-emitting layer is less than the thickness of the top light-emitting layer.

9. The polychromatic light source of claim 8, wherein, The thickness of the internal light-emitting layer is 40μm-120μm.

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