Csp lamp bead and manufacturing method thereof

Abstract

The application provides a CSP lamp bead and a manufacturing method thereof, wherein the CSP lamp bead comprises a light-transmitting unit and a light-emitting unit which are connected and stacked in sequence along a first direction, a plastic support is cancelled, and the overall size of the application is reduced; the light-transmitting unit comprises a transparent layer group and a high-color gamut fluorescent film layer, the high-color gamut fluorescent film layer is embedded in the inside of the transparent layer group; the light-emitting unit and the light-transmitting unit form at least three reflection cavities; the light-emitting unit comprises a first blue light chip, a green light chip and a second blue light chip which are arranged in sequence and at equal intervals along a second direction, the first blue light chip, the green light chip and the second blue light chip are arranged in the corresponding reflection cavities respectively, and the problem of light leakage from the side of the light-emitting chip is solved; the high-color gamut fluorescent film layer completely shields the first blue light chip and the green light chip, thereby replacing a red light chip, and the service life is improved; and the first blue light chip, the green light chip and the second blue light chip all have oppositely arranged light-emitting surfaces and electrode surfaces, and the light-emitting surfaces are arranged towards the light-transmitting unit.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a CSP lamp bead and its manufacturing method. Background Technology

[0002] As display technology iterates towards ultra-thinness, high contrast, wide color gamut, and pixel-level fine light control, the technical shortcomings of traditional RGB (Red-Green-Blue) light-emitting devices are becoming increasingly apparent, making them unable to meet the needs of high-end displays and precision lighting.

[0003] Traditional RGB LEDs use plastic brackets and copper leads, resulting in large package sizes and thicknesses. This makes it impossible to achieve micron-level micro-pixel arrangement. When applied to Mini LED (Mini Light Emitting Diode) backlighting and small-pitch displays, the large pixel pitch, obvious seams, and wide black border areas severely affect the overall display aesthetics and ultra-thin design.

[0004] Furthermore, the industry commonly uses a discrete mounting process for three chips: R (Red), G (Green), and B (Blue). The spacing between these three chips is uncontrollable, and the light relies solely on an external diffuser (light guide plate) for passive mixing. This easily leads to problems such as light spot layering, color shift, color spots, a blue center, and a red edge when the light is emitted at close range. Overall color calibration is difficult and costly, and batch production results in poor color gamut consistency, failing to meet the high color gamut display requirements for film and television.

[0005] Therefore, a new solution is needed to address the aforementioned technical problems. Summary of the Invention

[0006] This application provides a CSP lamp bead and its manufacturing method to solve the technical problems of large light-emitting structure size and high cost in related technologies.

[0007] On one hand, this application provides a CSP lamp bead, which includes a light-transmitting unit and a light-emitting unit stacked sequentially along a first direction; wherein, The light-transmitting unit includes a transparent layer group and a high color gamut fluorescent film layer, wherein the high color gamut fluorescent film layer is embedded inside the transparent layer group; The light-emitting unit forms at least three reflective cavities with the light-transmitting unit; the light-emitting unit includes a first blue light chip, a green light chip, and a second blue light chip arranged at equal intervals along a second direction, each of which is disposed within its corresponding reflective cavity; the high color gamut fluorescent film completely blocks the first blue light chip and the green light chip, and each of the first blue light chip, the green light chip, and the second blue light chip has a light-emitting surface and an electrode surface arranged opposite to each other, the light-emitting surface being disposed towards the light-transmitting unit; the first direction and the second direction are perpendicular to each other.

[0008] In one embodiment of this application, along the second direction, the outer periphery of the first blue light chip and the green light chip has a first end face and a second end face disposed opposite to each other, and the high color gamut fluorescent film layer has a third end face and a fourth end face disposed opposite to each other; the first end face is the end face of the first blue light chip, and the third end face near the first end face extends in a direction away from the first end face; the second end face is the end face of the green light chip, and the fourth end face near the second end face is flush with the second end face, or the fourth end face extends in a direction away from the second end face.

[0009] In one embodiment of this application, the transparent layer group includes a first transparent film layer and a second transparent film layer stacked sequentially along the first direction, the high color gamut fluorescent film layer is embedded in the second transparent film layer, and the second transparent film layer and the high color gamut fluorescent film layer are flush with the side facing the first transparent film layer.

[0010] In one embodiment of this application, the light-emitting unit further includes an annular dam, one end of which has an opening abuts against the light-transmitting unit and forms the reflective cavity with the light-transmitting unit; the outer peripheries of the first blue light chip, the green light chip and the second blue light chip are all covered by the annular dam.

[0011] In one embodiment of this application, the reflectivity of the inner wall of the annular dam is greater than or equal to 96%.

[0012] In one embodiment of this application, the electrode surface protrudes from the annular dam, and the electrode surfaces of the first blue light chip, the green light chip, and the second blue light chip are flush.

[0013] In one embodiment of this application, the spacing between the first blue light chip and the green light chip, and between the green light chip and the second blue light chip, is 50μm to 150μm.

[0014] In one embodiment of this application, the wavelength of the blue light emitted by the first blue light chip and the second blue light chip is 450nm~460nm; the wavelength of the green light emitted by the green light chip is 520nm~530nm; the half-width of the high color gamut red phosphor in the high color gamut fluorescent film layer is 3nm~5nm, the peak wavelength is 628nm~632nm, and the wavelength of the red light emitted by the high color gamut red phosphor excited by the blue light emitted by the first blue light chip is 626nm~634nm.

[0015] In one embodiment of this application, the CSP lamp bead further includes an adhesive film layer, and the light-transmitting unit and the light-emitting unit are connected through the adhesive film layer.

[0016] In one embodiment of this application, the CSP lamp bead has a length of 0.5mm to 2mm, a width of 0.5mm to 2mm, and a thickness of 0.4mm to 1mm.

[0017] On the other hand, this application also provides a method for manufacturing CSP lamp beads, for manufacturing CSP lamp beads as described in any of the above claims, the method comprising: A carrier film is provided, on which a transparent layer group and a high color gamut fluorescent film layer are printed, and each is subjected to a first curing treatment to form multiple light-transmitting units; A first blue light chip, a green light chip, and a second blue light chip are fixed on each group of light-transmitting units, and a second curing process is performed to form multiple groups of light-emitting units; wherein the first blue light chip and the green light chip are located above the high color gamut fluorescent film layer; Two adjacent CSP LED beads are cut at equal intervals to obtain multiple independent CSP LED beads; wherein each CSP LED bead includes a set of light-transmitting units and a set of light-emitting units; Multiple independent CSP LED beads are sequentially subjected to film casting, crystal expansion, and rearrangement to arrange the multiple independent CSP LED beads at equal intervals; Each CSP LED bead is subjected to photoelectric testing, and CSP LED beads of the same grade are bound together into rolls and stored in the warehouse.

[0018] In one embodiment of this application, a carrier film is provided, on which multiple sets of transparent layers and high color gamut fluorescent film layers are printed, and each is subjected to a first curing treatment to form multiple sets of light-transmitting units, including: The transparent layer group includes a first transparent film layer and a second transparent film layer; The first transparent film layer is printed on the carrier film, and the first transparent film layer is subjected to a first curing treatment; The high color gamut fluorescent film layer is printed in a local area of ​​the first transparent film layer, and the high color gamut fluorescent film layer is subjected to a first curing treatment. The second transparent film layer is printed on the first transparent film layer, and the second transparent film layer is subjected to a first curing treatment to form multiple sets of the light-transmitting units; wherein the first transparent film layer and the second transparent film layer completely cover the high color gamut fluorescent film layer.

[0019] In one embodiment of this application, fixing a first blue light chip, a green light chip, and a second blue light chip on each group of light-transmitting units, and performing a second curing process to form multiple groups of light-emitting units; wherein the first blue light chip and the green light chip are located above the high color gamut fluorescent film layer, including: An adhesive film layer is attached to the upper surface of the light-transmitting unit; The light-emitting surfaces of the first blue light chip, the green light chip, and the second blue light chip are bonded to the adhesive film layer according to the first preset matrix coordinates; Adhesive is applied to the circumference of the first blue light chip, the green light chip, and the second blue light chip to form a ring-shaped dam. The annular dam is subjected to a second curing process to form the light-emitting unit.

[0020] In one embodiment of this application, the first curing process includes: The light-transmitting unit is baked at a temperature of 100℃~160℃ for 1H~2H. The second curing process includes: The light-emitting unit having the light-transmitting unit is baked at a temperature of 100℃ to 160℃ for 2H to 8H.

[0021] The beneficial effects of this application are as follows: The CSP lamp bead and its manufacturing method proposed in this application eliminate the plastic bracket by setting a light-transmitting unit and a light-emitting unit, and adopt a substrate-free structure, which helps to reduce the overall structural size of this application; and the combination of the first blue light chip and the high color gamut fluorescent film layer can replace the use of the red light chip, thereby avoiding the pain point of asynchronous decay of the three-color chips due to the premature decay of the red light chip, which helps to improve the service life of this application and also helps to reduce costs; furthermore, the setting of the reflective cavity helps to solve the problem of lateral light leakage of the light-emitting chip, thereby ensuring the consistency of the color gamut of the product during mass production; and the light-emitting surface of the light-emitting chip is set facing the light-transmitting unit, while the electrode surface is set away from the light-transmitting unit, so that the light-emitting surface of the light-emitting chip is unobstructed, which helps to improve the light extraction efficiency. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0023] In the attached diagram: Figure 1 This is a schematic diagram of the structure of a CSP lamp bead provided in one embodiment of this application; Figure 2 This is a bottom view of the CSP lamp bead provided in one embodiment of this application; Figure 3 for Figure 2 Sectional view of AA; Figure 4 This is a flowchart of a CSP lamp bead manufacturing method provided in one embodiment of this application.

[0024] The attached figures are labeled as follows: 1-High color gamut fluorescent film layer; 11-Third end face; 12-Fourth end face; 2- First transparent film layer; 3-Second transparent film layer; 4-First blue light chip; 41-First end face; 5-Green light chip; 51-Second end face; 6-Second blue light chip; 7- Circular dike; 8-Electrode surface; 9- Adhesive film layer. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.

[0028] Please see Figures 1 to 3 One embodiment of this application provides a CSP (Chip Scale Package) LED bead, including a light-transmitting unit and a light-emitting unit. It eliminates the plastic support and adopts a substrate-free structure, which helps reduce the overall structural size of the application. This allows the application to be used in Mini LED backlighting and small-pitch displays, facilitating ultra-thin design and improving the display's visual appeal. The light-transmitting unit and the light-emitting unit are stacked and connected along a first direction. Exemplarily, the first direction is... Figure 1 The Z direction in the equation.

[0029] The light-transmitting unit includes a transparent layer assembly and a high color gamut fluorescent film layer 1. The high color gamut fluorescent film layer 1 is embedded within the transparent layer assembly. Because the high color gamut fluorescent film layer 1 is hydrophilic and easily hydrolyzes and turns black, embedding it within the transparent layer assembly improves its airtightness and waterproof / sulfurization-resistant properties, thereby enhancing the reliability of this application.

[0030] For example, the high color gamut fluorescent film layer 1 is made of transparent silicone and high color gamut red phosphor, which are uniformly stirred together.

[0031] In one example, the transparent layer assembly includes a first transparent film layer 2 and a second transparent film layer 3, which are stacked and connected sequentially along a first direction. A high color gamut fluorescent film layer 1 is embedded within the second transparent film layer 3, and the sides of the second transparent film layer 3 and the high color gamut fluorescent film layer 1 facing the first transparent film layer 2 are flush, thereby ensuring that the high color gamut fluorescent film layer 1 is completely enclosed by the first transparent film layer 2 and the second transparent film layer 3. This arrangement helps to ensure that the light-emitting surface of the light-transmitting unit is flat and smooth, facilitates the fusion of three colors of light, and ensures uniform light emission.

[0032] For example, the second transparent film layer 3 is positioned close to the light-emitting unit, which helps reduce the manufacturing difficulty of the transparent layer assembly. The first transparent film layer 2 and the second transparent film layer 3 are made of colorless transparent silicone or the like.

[0033] In one embodiment, the light-emitting unit includes a first blue light chip 4, a green light chip 5, and a second blue light chip 6. The first blue light chip 4, the green light chip 5, and the second blue light chip 6 are arranged sequentially at equal intervals along a second direction, which helps to ensure the consistency of light emission from the light-emitting unit. For example, the first blue light chip 4, the green light chip 5, and the second blue light chip 6 are all flip chips.

[0034] The first direction and the second direction are perpendicular to each other. For example, the second direction is... Figure 1 The X direction in the equation.

[0035] In one example, the spacing between the first blue light chip 4 and the green light chip 5, and between the green light chip 5 and the second blue light chip 6, is 50μm to 150μm, which helps to ensure uniform spacing.

[0036] In one embodiment, the light-emitting unit and the light-transmitting unit form at least three reflective cavities, and the first blue light chip 4, the green light chip 5, and the second blue light chip 6 each have their own corresponding reflective cavity. By placing the light-emitting chips inside the reflective cavities, the problem of lateral light leakage from the light-emitting chips is effectively solved. When this application is applied to zoned dynamic backlighting, the above arrangement helps prevent crosstalk between adjacent pixels, ensures the clarity of the backlight zone boundaries, improves image contrast, and achieves precise pixel-level light control. Simultaneously, the controllable light emission angle expands the applicable scenarios of this application.

[0037] In this embodiment, there are three reflective cavities. The first reflective cavity contains a first blue light chip 4, the second reflective cavity contains a green light chip 5, and the third reflective cavity contains a second blue light chip 6.

[0038] In some embodiments, to form a reflective cavity, one open end face of the annular dam 7 abuts against the light-transmitting unit to form a reflective cavity with the light-transmitting unit. Furthermore, the outer peripheries of the first blue light chip 4, the green light chip 5, and the second blue light chip 6 are all covered by the annular dam 7, which helps to solve the problem of lateral light leakage from the light-emitting chips. Moreover, the annular dam 7 also protects the edges of the light-emitting chips and helps to alleviate the thermal expansion and contraction stress generated by the light-emitting chips during high-temperature-low-temperature cycling, reducing the risk of delamination and cracking of the light-emitting chips, and thus improving the long-term reliability of this application.

[0039] In one example, the reflectivity of the inner wall of the annular dam 7 is greater than or equal to 96%, thereby constraining the light to emerge along the first direction, isolating the light from lateral crosstalk, and preventing cross-coloring between the three colors, which helps to ensure color purity and color gamut accuracy.

[0040] For example, the material of the annular dam 7 is white high-reflectivity silicone, etc.

[0041] In one embodiment, the first blue light chip 4 and the green light chip 5 are completely blocked by the high color gamut fluorescent film layer 1. Since the blue light emitted by the first blue light chip 4 can excite the high color gamut fluorescent film layer 1 to emit red light, and the green light emitted by the green light chip 5 will not excite the high color gamut fluorescent film layer 1, by designing the high color gamut fluorescent film layer 1 to completely block the first blue light chip 4 and the green light chip 5, the area of ​​the high color gamut fluorescent film layer 1 blocking the first blue light chip 4 is increased. This helps to prevent the light emitted by the first blue light chip 4 from leaking out through the edge of the high color gamut fluorescent film layer 1, thereby ensuring the purity of the red light emitted through the high color gamut fluorescent film layer 1.

[0042] Furthermore, by combining the first blue light chip 4 and the high color gamut fluorescent film layer 1, the red light chip can be eliminated. Since the red light chip ages earlier than the blue and green light chips 5, eliminating the red light chip solves the problem of asynchronous decay of the three colors, thus improving the lifespan of this application. At the same time, eliminating the red light chip also helps reduce costs.

[0043] In one example, the blue light emitted by the first blue light chip 4 and the second blue light chip 6 has a wavelength of 450nm~460nm, and the high color gamut red phosphor in the high color gamut fluorescent film layer 1 has a half-width of 3nm~5nm and a peak wavelength of 628nm~632nm. When the first blue light chip 4 emits blue light, this blue light can excite the high color gamut red phosphor to emit red light with a wavelength of 626nm~634nm. Furthermore, the high color gamut red phosphor has no spectral self-absorption, which is beneficial for improving the efficiency of converting high color gamut fluorescent film layer 1 into red light after blue light excitation, thus resulting in higher overall brightness under the same current. For example, the wavelength of the blue light can be 450nm, 453nm, 457nm, 460nm, etc. The half-width of the high color gamut red phosphor can be 3nm, 4nm, 5nm, etc., and the peak wavelength can be 628nm, 630nm, 632nm, etc. The blue light emitted by the first blue light chip 4 excites the red light emitted by the high color gamut red phosphor to have wavelengths of 626nm, 630nm, 634nm, etc.

[0044] The green light emitted by the green light chip 5 has a wavelength of 520nm~530nm, thus preventing the green light from exciting the high color gamut fluorescent film layer 1. For example, the wavelength of the green light can be 520nm, 525nm, 528nm, 530nm, etc.

[0045] In some embodiments, since the first blue light chip 4, the green light chip 5, and the second blue light chip 6 are arranged at equal intervals along the second direction, the distances between the two end faces of the first blue light chip 4 and the end faces of the light-transmitting unit and the green light chip 5, respectively, are small along the second direction, posing a risk of blue light leakage. However, along the third direction, the distances between the two end faces of the first blue light chip 4 and the two end faces of the transparent unit are larger, thus avoiding the risk of blue light leakage. Therefore, when considering the blocking effect of the high color gamut fluorescent film layer 1 on the first blue light chip 4, this application focuses more on the blocking along the second direction. For example, the third direction is... Figure 1 in the Y direction.

[0046] To increase the area of ​​the high color gamut fluorescent film layer 1 covering the first blue light chip 4, along the second direction, the outer peripheries of the first blue light chip 4 and the green light chip 5 have a first end face 41 and a second end face 51 disposed opposite to each other, and the high color gamut fluorescent film layer 1 has a third end face 11 and a fourth end face 12 disposed opposite to each other. Specifically, the first end face 41 is the end face of the first blue light chip 4, and the third end face 11 is disposed close to the first end face 41 and extends in a direction away from the first end face 41. The second end face 51 is the end face of the green light chip 5, and the fourth end face 12 is disposed close to the second end face 51, and the fourth end face 12 is flush with the second end face 51; alternatively, the fourth end face 12 extends in a direction away from the second end face 51.

[0047] It should be noted that when the fourth end face 12 extends in a direction away from the second end face 51, the high color gamut fluorescent film layer 1 cannot block the second blue light chip 6 in any way, which helps to ensure the purity of the blue light emitted by the second blue light chip 6.

[0048] In one embodiment, the first blue light chip 4, the green light chip 5, and the second blue light chip 6 each have a light-emitting surface and an electrode surface 8 arranged opposite to each other. The light-emitting surface faces the light-transmitting unit, while the electrode surface 8 faces away from the light-transmitting unit. This ensures that the light-emitting surface of the light-emitting chip is unobstructed, and the light emitted by the chip only penetrates the light-transmitting unit, which improves light extraction efficiency and reduces energy consumption in subsequent applications of the backlight module of this application. Furthermore, this arrangement allows the electrode surface at the bottom of the light-emitting chip to be directly soldered onto the PCB (Printed Circuit Board), shortening the heat conduction path and reducing thermal resistance; it eliminates the need for a lead frame and a separate PCB, resulting in an overall volume close to that of a bare chip, facilitating high-density array arrangement; and the absence of gold wire connection structures reduces the risk of gold wire breakage and failure.

[0049] In one example, to facilitate connection of this application to a PCB board, the electrode surfaces 8 of the first blue light chip 4, the green light chip 5, and the second blue light chip 6 all protrude from the annular dam 7. Furthermore, the electrode surfaces 8 of the first blue light chip 4, the green light chip 5, and the second blue light chip 6 are flush.

[0050] In some embodiments, an adhesive film layer 9 is provided between the light-transmitting unit and the light-emitting unit to achieve connection between them. The light-transmitting unit and the light-emitting unit are bonded together by the adhesive film layer 9.

[0051] For example, the adhesive film layer 9 can be a transparent OCA film (Optically Clear Adhesive) with adhesive properties.

[0052] In some embodiments, the CSP LED bead of this application has a length of 0.5mm to 2mm, a width of 0.5mm to 2mm, and a thickness of 0.4mm to 1mm, enabling this application to be used in thinner devices, curved screens, or irregularly shaped screens. From an optical perspective, by setting the external structure of this application to the above dimensions, the local light control of the screen is more precise, the color mixing effect is better, the viewing angle is more uniform, and a higher PPI (Pixels Per Inch) and a lower minimum brightness (low grayscale performance) can also be achieved.

[0053] In summary, the CSP lamp bead provided in this application eliminates the plastic bracket and adopts a substrate-free structure by setting a light-transmitting unit and a light-emitting unit, which helps to reduce the overall structural size of this application. Moreover, the combination of the first blue light chip and the high color gamut fluorescent film layer can replace the use of the red light chip, thereby avoiding the pain point of asynchronous decay of the three-color chips due to the premature decay of the red light chip, which helps to improve the service life of this application and also helps to reduce costs. Furthermore, the setting of the reflective cavity helps to solve the problem of lateral light leakage of the light-emitting chip, thereby ensuring the consistency of the color gamut of the product during mass production. In addition, the light-emitting surface of the light-emitting chip is set towards the light-transmitting unit, and the electrode surface is set away from the light-transmitting unit, so that the light-emitting surface of the light-emitting chip is unobstructed, which helps to improve the light extraction efficiency.

[0054] Please see Figure 4 An embodiment of this application also provides a method for manufacturing CSP LED chips. The method for manufacturing CSP LED chips includes at least steps S410 to S450, which are described in detail below: Step S410: A carrier film is provided, and a transparent layer group and a high color gamut fluorescent film layer 1 are printed on the carrier film, and a first curing treatment is performed on each of them to form multiple sets of light-transmitting units.

[0055] In some embodiments, a carrier film is fixed on a horizontal marble slab, and then a transparent layer assembly is printed on the upper surface of the carrier film using a coating printing machine. A high color gamut fluorescent film layer 1 is printed using a screen printing machine, and the transparent layer assembly and the high color gamut fluorescent film layer 1 are respectively subjected to a first curing treatment to form a light-transmitting unit. To reduce production costs and improve production efficiency, multiple light-transmitting units can be printed on the carrier film simultaneously.

[0056] For example, the carrier film can be a release film, such as 2400-I matte antistatic fluoroplastic film.

[0057] In some embodiments, the transparent layer assembly includes a first transparent film layer 2 and a second transparent film layer 3. During the printing process, the coating printing machine first prints the first transparent film layer 2 on the upper surface of the carrier film. For example, the thickness of the first transparent film layer 2 can be 30μm to 100μm, adaptively selected according to the design thickness of the CSP LED beads, and the thickness accuracy of the first transparent film layer 2 can reach ±3μm.

[0058] After the first transparent film layer 2 is printed, the carrier film printed with the first transparent film layer 2 is placed in a silicone baking oven for baking to cure the first transparent film layer 2. In one example, the temperature inside the silicone baking oven can be set to 100℃ to 160℃, and the first transparent film layer 2 is baked for 1 hour to 2 hours. Exemplarily, after the carrier film is placed in the silicone baking oven, the silicone baking oven is started and begins to heat up for 0.5 hours; before the carrier film is removed from the silicone baking oven, the oven cools down for 0.5 hours.

[0059] After the first transparent film layer 2 has cured, the carrier film is fixed on the fixture of the screen printing machine, and the high color gamut fluorescent film layer 1 is printed on a local area of ​​the upper surface of the first transparent film layer 2 using the screen printing machine. For example, the thickness of the printed high color gamut fluorescent film layer 1 can be 50μm to 250μm, adaptively selected according to the design thickness of the CSP LED and the set photoelectric parameters, and the thickness accuracy of the high color gamut fluorescent film layer 1 can reach ±3μm. In one example, a corresponding screen printing plate needs to be made before printing the high color gamut fluorescent film layer 1. A suitable mesh size screen is selected based on the required thickness of the high color gamut fluorescent film layer 1 to be printed, and the plate is made in conjunction with the required photosensitive emulsion coating thickness to meet printing accuracy requirements.

[0060] After the high color gamut fluorescent film layer 1 is printed, the carrier film printed with the high color gamut fluorescent film layer 1 is placed in a silicone baking oven for baking to cure the high color gamut fluorescent film layer 1. In one example, the temperature inside the silicone baking oven can be set to 100°C to 160°C, and the high color gamut fluorescent film layer 1 is baked for 1 to 2 hours. Exemplarily, after the carrier film is placed in the silicone baking oven, the silicone baking oven is started and begins to heat up for 0.5 hours; before the carrier film is removed from the silicone baking oven, the oven cools down for 0.5 hours.

[0061] After the high color gamut fluorescent film layer 1 has cured, the carrier film is re-fixed onto the horizontal marble, and a second transparent film layer 3 is printed on the upper surface of the first transparent film layer 2 using a coating printing machine. The first transparent film layer 2 and the second transparent film layer 3 completely cover the high color gamut fluorescent film layer 1, thereby blocking contact between the high color gamut fluorescent film layer 1 and the external environment, which helps improve the reliability of the high color gamut fluorescent film layer 1. For example, the thickness of the printed second transparent film layer 3 can be 70μm to 270μm, adaptively selected according to the printing thickness of the high color gamut fluorescent film layer 1, to ensure that the printing thickness of the second transparent film layer 3 is greater than 20μm compared to the printing thickness of the high color gamut fluorescent film layer 1. Furthermore, the thickness accuracy of the second transparent film layer 3 can reach ±3μm.

[0062] After the second transparent film layer 3 is printed, the carrier film with the printed second transparent film layer 3 is placed in a silicone baking oven for baking to cure the second transparent film layer 3, thereby forming multiple sets of light-transmitting units. In one example, the temperature inside the silicone baking oven can be set to 100℃ to 160℃, and the second transparent film layer 3 is baked for 1 hour to 2 hours. Exemplarily, after the carrier film is placed in the silicone baking oven, the silicone baking oven is started and begins to heat up for 0.5 hours; before the carrier film is removed from the silicone baking oven, the oven cools down for 0.5 hours.

[0063] In step S420, a first blue light chip 4, a green light chip 5, and a second blue light chip 6 are fixed on each group of light-transmitting units, and a second curing process is performed to form multiple groups of light-emitting units; wherein, the first blue light chip 4 and the green light chip 5 are located above the high color gamut fluorescent film layer 1.

[0064] In some embodiments, after forming light-transmitting units on the carrier film, a first blue light chip 4, a green light chip 5, and a second blue light chip 6 are fixed on each group of light-transmitting units using an automatic die bonding machine and an automatic dispensing machine. The first blue light chip 4 and the green light chip 5 are located above the high color gamut fluorescent film layer 1, thereby eliminating the red light chip through the combination of the first blue light chip 4 and the high color gamut fluorescent film layer 1. Subsequently, a second curing process is performed to form multiple groups of light-emitting units on the carrier film.

[0065] In one example, an adhesive film layer 9 is first attached to the upper surface of the light-transmitting unit. Air bubbles between the upper surface of the light-transmitting unit and the adhesive film layer 9 are removed by pressing and vacuuming, ensuring that the adhesive film layer 9 is completely attached to the upper surface of the light-transmitting unit, which improves the stability of the connection. For example, the thickness of the adhesive film layer 9 is 15 μm.

[0066] Subsequently, the carrier film with the adhesive film layer 9 attached is placed on a square metal support frame, and an automatic die bonding machine is used to bond the first blue light chip 4, the green light chip 5, and the second blue light chip 6 onto the adhesive film layer 9 according to the first preset matrix coordinates. The light-emitting surfaces of the first blue light chip 4, the green light chip 5, and the second blue light chip 6 are bonded to the adhesive film layer 9, and the electrode surfaces 8 of the first blue light chip 4, the green light chip 5, and the second blue light chip 6 face away from the light-transmitting unit, so that the light-emitting surfaces of the light-emitting chips are unobstructed.

[0067] Then, an automatic dispensing machine is used to apply white high-reflectivity silicone to the circumference of the first blue light chip 4, the green light chip 5, and the second blue light chip 6, forming an annular dam 7. This ensures that the upper surface of the adhesive film layer 9 is filled with the first blue light chip 4, the green light chip 5, the second blue light chip 6, and the white high-reflectivity silicone. The electrode surface 8 of the light-emitting chip is exposed outside the annular dam 7.

[0068] After the annular dam 7 is formed, the carrier film with the annular dam 7 is placed in a silicone baking oven for baking to solidify the annular dam 7, thereby forming multiple sets of light-emitting units. In one example, the temperature inside the silicone baking oven can be set to 100°C to 160°C, and the annular dam 7 is baked for 2 to 8 hours. Exemplarily, after the carrier film is placed in the silicone baking oven, the oven is started and begins to heat up for 0.5 hours to reach a temperature of 50°C, and then baked at a constant temperature of 50°C for 0.5 hours. Subsequently, the temperature is increased for another 0.5 hours to reach 100°C, and then baked at a constant temperature of 100°C for 0.5 hours. Then, the temperature is increased for another 0.5 hours to reach 160°C, and then baked at a constant temperature of 160°C for 4 hours. Before the carrier film is removed from the silicone baking oven, the oven is cooled down for 0.5 hours.

[0069] Step S430: Cut two adjacent CSP LED beads at equal intervals to obtain multiple independent CSP LED beads; wherein each CSP LED bead includes a set of light-transmitting units and a set of light-emitting units.

[0070] In some embodiments, after the light-emitting units are formed on the carrier film, the carrier film will have multiple CSP LEDs merged together. A cutting machine is used to cut adjacent CSP LEDs at equal intervals to obtain multiple independent CSP LEDs, facilitating subsequent processes. Each CSP LED includes a set of light-transmitting units and a set of light-emitting units. It should be noted that the carrier film is not cut during the cutting process.

[0071] Step S440 involves sequentially performing film casting, crystal expansion, and rearrangement on multiple independent CSP LEDs to arrange them at equal intervals.

[0072] In some embodiments, a first blue film is applied to the upper surface of the cut CSP LED beads, and the electrode surface 8 of the light-emitting chip is attached to the first blue film. The first blue film is then attached to the carrier film. Subsequently, the bonded first blue film, CSP LED beads, and carrier film are flipped 180° so that the electrode surface 8 of the light-emitting chip faces downwards and the carrier film faces upwards, and the carrier film is peeled off. Then, a die expander is used to uniformly stretch the first blue film to increase the distance between adjacent CSP LED beads. Finally, an automatic die bonder is used to arrange the multiple independent CSP LED beads at equal intervals according to a second preset matrix coordinate system.

[0073] Step S450: Perform photoelectric testing on each CSP LED bead, and then compile CSP LED beads of the same grade into a roll and put it into storage.

[0074] In some embodiments, a spectrometer is used to separate each CSP LED chip according to a pre-set photoelectric parameter range. Then, a sorting machine is used to place CSP LED chips with the same photoelectric parameter range onto the same second blue film. Subsequently, a tape and reel machine is used to tape the CSP LED chips with the same photoelectric parameter range into rolls. The rolls of CSP LED chips are then placed into aluminum foil bags and vacuum-sealed. A label with the corresponding photoelectric parameter range is then affixed to the aluminum foil bags, and finally, they are stored in the warehouse.

[0075] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A CSP LED bead, characterized in that, It includes light-transmitting units and light-emitting units that are stacked and connected sequentially along a first direction; wherein, The light-transmitting unit includes a transparent layer group and a high color gamut fluorescent film layer, wherein the high color gamut fluorescent film layer is embedded inside the transparent layer group; The light-emitting unit forms at least three reflective cavities with the light-transmitting unit; the light-emitting unit includes a first blue light chip, a green light chip, and a second blue light chip arranged at equal intervals along a second direction, each of which is disposed within its corresponding reflective cavity; the high color gamut fluorescent film completely blocks the first blue light chip and the green light chip, and each of the first blue light chip, the green light chip, and the second blue light chip has a light-emitting surface and an electrode surface arranged opposite to each other, the light-emitting surface being disposed towards the light-transmitting unit; the first direction and the second direction are perpendicular to each other.

2. The CSP lamp bead according to claim 1, characterized in that, Along the second direction, the outer periphery of the first blue light chip and the green light chip has a first end face and a second end face disposed opposite to each other, and the high color gamut fluorescent film layer has a third end face and a fourth end face disposed opposite to each other; the first end face is the end face of the first blue light chip, and the third end face near the first end face extends in a direction away from the first end face; the second end face is the end face of the green light chip, and the fourth end face near the second end face is flush with the second end face, or the fourth end face extends in a direction away from the second end face.

3. The CSP lamp bead according to claim 1, characterized in that, The transparent layer group includes a first transparent film layer and a second transparent film layer stacked sequentially along the first direction. The high color gamut fluorescent film layer is embedded in the second transparent film layer, and the second transparent film layer and the high color gamut fluorescent film layer are flush with the side facing the first transparent film layer.

4. The CSP lamp bead according to claim 1, characterized in that, The light-emitting unit further includes an annular dam, one end of which has an opening abuts against the light-transmitting unit and forms the reflective cavity with the light-transmitting unit; the outer periphery of the first blue light chip, the green light chip and the second blue light chip are all covered by the annular dam, and the reflectivity of the inner wall of the annular dam is greater than or equal to 96%.

5. The CSP lamp bead according to claim 1, characterized in that, The blue light emitted by the first and second blue light chips has a wavelength of 450nm~460nm; the green light emitted by the green light chip has a wavelength of 520nm~530nm; the high color gamut red phosphor of the high color gamut fluorescent film has a half-width of 3nm~5nm and a peak wavelength of 628nm~632nm, and the blue light emitted by the first blue light chip excites the red light emitted by the high color gamut red phosphor to have a wavelength of 626nm~634nm.

6. The CSP lamp bead according to any one of claims 1-5, characterized in that, The CSP lamp bead also includes an adhesive film layer, through which the light-transmitting unit and the light-emitting unit are connected; the CSP lamp bead has a length of 0.5mm~2mm, a width of 0.5mm~2mm, and a thickness of 0.4mm~1mm.

7. A method for manufacturing CSP LED chips, characterized in that, The method for manufacturing a CSP lamp bead as described in any one of claims 1-6 comprises: A carrier film is provided, on which a transparent layer group and a high color gamut fluorescent film layer are printed, and each is subjected to a first curing treatment to form multiple light-transmitting units; A first blue light chip, a green light chip, and a second blue light chip are fixed on each group of light-transmitting units, and a second curing process is performed to form multiple groups of light-emitting units; wherein the first blue light chip and the green light chip are located above the high color gamut fluorescent film layer; Two adjacent CSP LED beads are cut at equal intervals to obtain multiple independent CSP LED beads; wherein each CSP LED bead includes a set of light-transmitting units and a set of light-emitting units; Multiple independent CSP LED beads are sequentially subjected to film casting, crystal expansion, and rearrangement to arrange the multiple independent CSP LED beads at equal intervals; Each CSP LED bead is subjected to photoelectric testing, and CSP LED beads of the same grade are bound together into rolls and stored in the warehouse.

8. The CSP lamp bead manufacturing method according to claim 7, characterized in that, The method provides a carrier film, on which multiple sets of transparent layers and high color gamut fluorescent film layers are printed, and each is subjected to a first curing treatment to form multiple sets of light-transmitting units, including: The transparent layer group includes a first transparent film layer and a second transparent film layer; The first transparent film layer is printed on the carrier film, and the first transparent film layer is subjected to a first curing treatment; The high color gamut fluorescent film layer is printed in a local area of ​​the first transparent film layer, and the high color gamut fluorescent film layer is subjected to a first curing treatment. The second transparent film layer is printed on the first transparent film layer, and the second transparent film layer is subjected to a first curing treatment to form multiple sets of the light-transmitting units; wherein the first transparent film layer and the second transparent film layer completely cover the high color gamut fluorescent film layer.

9. The CSP lamp bead manufacturing method according to claim 7, characterized in that, The process involves fixing a first blue light chip, a green light chip, and a second blue light chip onto each group of light-transmitting units, followed by a second curing process to form multiple groups of light-emitting units; wherein the first blue light chip and the green light chip are located above the high color gamut fluorescent film layer, comprising: An adhesive film layer is attached to the upper surface of the light-transmitting unit; The light-emitting surfaces of the first blue light chip, the green light chip, and the second blue light chip are bonded to the adhesive film layer according to the first preset matrix coordinates; Adhesive is applied to the circumference of the first blue light chip, the green light chip, and the second blue light chip to form a ring-shaped dam. The annular dam is subjected to a second curing process to form the light-emitting unit.

10. The CSP lamp bead manufacturing method according to claim 8 or 9, characterized in that, The first curing process includes: The light-transmitting unit is baked at a temperature of 100℃~160℃ for 1H~2H. The second curing process includes: The light-emitting unit having the light-transmitting unit is baked at a temperature of 100℃ to 160℃ for 2H to 8H.

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