LED light source and preparation method thereof

Abstract

According to the LED light source and the preparation method thereof provided by the invention, the whole fluorescent diaphragm adhered with the LED chip is cut to mount the fluorescent diaphragm, so that the utilization efficiency of the fluorescent diaphragm is improved; the LED chips on which the fluorescent diaphragms meeting different light-emitting requirements are independently attached are directly packaged into a whole by adopting a CSP packaging technology, and then the LED lighting device capable of meeting various light-emitting requirements can be obtained through one-time surface mounting by adopting a surface mounting technology; compared with a traditional gradual single-chip mounting scheme, the LED lighting device has the advantages that the gap between the LED chips can be obviously reduced, and the area occupied by the whole LED lighting device can be reduced; meanwhile, the gaps between the adjacent LED chips are reduced, so that uniform light spots can be more effectively formed during light mixing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an LED light source and its fabrication method. Background Technology

[0002] As consumer demands become increasingly diversified, the market's requirements for lighting products are also rising. LED light sources can achieve a wider range of color temperature and color adjustment by combining LEDs to meet different light emission needs, thereby providing richer and more realistic lighting effects to meet personalized needs in different occasions; such as dual-color temperature LED light sources for mobile phone flashlights and RGBW structure LED light sources for stage lighting.

[0003] Currently, LED light source fabrication typically employs a chip-by-chip approach, where multiple LED chips, each emitting light to meet different requirements, are sequentially soldered onto specific areas of a conductive substrate. This method requires pre-packaging each LED chip to be mounted, resulting in a large overall module size and demanding precise placement of each LED chip at a designated position on the conductive substrate. Furthermore, it is difficult to ensure that the centers of adjacent light sources are aligned, leading to the appearance of alternating bright and dark interference fringes at the gaps between adjacent light sources after adding lenses to the module. Summary of the Invention

[0004] To overcome the above shortcomings, the present invention provides an LED light source and its preparation method, which can effectively solve the technical problems of high difficulty in chip mounting and uneven light output in the prior art.

[0005] The technical solution provided by this invention is as follows: On one hand, the present invention provides a method for preparing an LED light source, comprising: Provides multiple fluorescent films to meet different luminescence requirements; LED chips with the same light emission requirements are regularly adhered to the surface of the same fluorescent film; the LED chip includes a light-emitting top surface, a chip side surface, and an electrode surface opposite to the light-emitting top surface, and the LED chip is adhered to the surface of the fluorescent film through the light-emitting top surface; Each fluorescent film is cut along the gap between adjacent LED chips to obtain an LED structure containing a preset number of LED chips and having the same fluorescent film attached to its surface. Based on the light emission requirements of LED light sources, LED structures with different types of fluorescent films are arranged on the surface of the support film in a regular manner with the electrodes facing upward, taking one LED light source as a unit. High-reflectivity white glue is filled into the gap between adjacent LED chips, and the high-reflectivity white glue at least covers the light-emitting side and the side of the fluorescent film of the LED chip; The LED light source is obtained by cutting an LED light source into units, thus completing the fabrication of the LED light source.

[0006] On the other hand, the present invention provides an LED light source, which is prepared by the above-described preparation method; comprising: multiple LED chips, each LED chip including a light-emitting surface, a chip side surface, and an electrode surface opposite to the light-emitting surface; multiple fluorescent films formed on the surface of the multiple LED chips, the multiple fluorescent films being prepared to meet different light-emitting requirements; and high-reflectivity white glue at least surrounding the light-emitting side surface of the LED chips, with the high-reflectivity white glue filling the spaces between different types of fluorescent films.

[0007] The LED light source and its manufacturing method provided by this invention utilize a method of cutting the entire fluorescent film after the LED chip is attached to improve the utilization efficiency of the fluorescent film and enhance the mounting accuracy, avoiding problems such as misalignment of the light-emitting center that may occur when the fluorescent film is cut and attached to the LED chip surface. Simultaneously, CSP packaging technology is used to directly encapsulate LED chips, each with a fluorescent film to meet different light-emitting requirements, into a single unit. Furthermore, white adhesive is placed between adjacent LED chips in the LED light source, allowing for a single surface mount technology (SMT) process to obtain an LED lighting device that meets multiple light-emitting needs. Compared to the traditional method of mounting different LED structures one by one, this significantly reduces the gap between LED chips, thus reducing the overall area occupied by the LED lighting device. Because the gap between adjacent LED chips in the LED light source is reduced, a more uniform light spot can be formed more effectively during light mixing. Attached Figure Description

[0008] Figure 1 This is a cross-sectional schematic diagram of LED chips arranged on the surface of a fluorescent film in one embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of a fluorescent film cut in one embodiment of the present invention; Figure 3 This is a bottom view of an embodiment of the present invention showing the LED structure arranged on the surface of a support film; Figure 4 This is a bottom view of another embodiment of the present invention showing the LED structure arranged on the surface of the support film; Figure 5 This is a cross-sectional schematic diagram of the white glue filling in one embodiment of the present invention; Figure 6 This is a top view schematic diagram of a dual-color temperature LED light source in one embodiment of the present invention; Figure 7 for Figure 6 Cross-sectional schematic diagram of the AA section of the dual-color temperature LED light source; Figure 8This is a top view schematic diagram of an LED light source with an RGBW structure in one embodiment of the present invention.

[0009] Figure label: 10-Fluorescent film, 11-Release film, 12-Support film, 20-LED chip, 21-Light-emitting top surface, 22-Chip side surface, 23-Electrode surface, 24-Chip electrode, 30-High reflectivity white adhesive, 40-LED light source. Detailed Implementation

[0010] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0011] One embodiment of the present invention provides a method for preparing an LED light source, comprising: S10 offers multiple fluorescent films to meet different luminescence requirements.

[0012] The provided fluorescent film is manufactured as a single sheet, without cutting. The fluorescent film 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 composition can be at least one or more of the following: garnet phosphor, oxynitride phosphor, aluminate phosphor, nitride phosphor, sulfide phosphor, KSF phosphor, etc.

[0013] Different types of fluorescent films contain phosphors that, when excited by light emitted from the same LED chip, are converted to produce light that meets different light emission requirements. These different light emission requirements refer to the different photoelectric parameters of the light emitted by the fluorescent film after being excited by the LED chip, including color temperature, color rendering index, RGB values, etc. In other words, the light emitted by the fluorescent film after being converted by the LED chip can have different color temperatures, color rendering indices, or RGB values. LED light sources typically emit more than one type of light, especially different colors of light. Depending on the requirements, a corresponding fluorescent film is provided for different light outputs. Technicians can prepare fluorescent films that meet the corresponding requirements in advance according to the light emission requirements of the LED light source.

[0014] S20. LED chips with the same light emission requirements are regularly adhered to the surface of the same fluorescent film; the LED chip includes a light-emitting top, a chip side, and an electrode surface opposite to the light-emitting top, and the LED chip is adhered to the surface of the fluorescent film through the light-emitting top.

[0015] In this step, individual fluorescent films meeting different light-emitting requirements are placed on the surface of the release film. The release film only serves as a supporting platform and has no adhesive properties, making it easy to remove the LED chips with the fluorescent films attached later. Figure 1 As shown, multiple LED chips 20 with the same light-emitting requirements are closely arranged on the surface of each fluorescent film 10. The light-emitting surface 21 of the LED chips is attached to the surface of the fluorescent film, and the chip electrodes 24 on the electrode surface 23 face upwards. At this time, there is a gap between adjacent LED chips, and the chip sides 22 do not contact each other, which facilitates the subsequent cutting of the fluorescent film between adjacent LED chips. At the same time, the gap between LED chips should be as small as possible while meeting the light-emitting requirements to make full use of the fluorescent film. By cutting the entire fluorescent film after the LED chips are attached, the utilization efficiency and installation efficiency of the fluorescent film are improved. In this step, the LED chips attached to the same fluorescent film surface are the same, all of which are flip-chip chips, with the electrodes facing away from the fluorescent film. The light-emitting performance of the LED chips themselves is the same. For example, flip-chip blue LED chips are used, that is, the LED chips themselves emit blue light. By regularly attaching flip-chip blue LED chips that meet the same light-emitting requirements to the same fluorescent film surface, the performance of multiple LED structures from the same fluorescent film after cutting is the same, which is convenient for subsequent applications. In other embodiments, green light chips, ultraviolet light chips, etc., can also be used, and the appropriate chip can be selected according to actual needs.

[0016] Before providing the fluorescent film in step S10, the process of preparing the fluorescent film also includes the following: S01 mixes different colored phosphors with silica gel in a certain proportion to obtain a variety of mixtures with different ratios, which correspond to the different light emission requirements of multiple fluorescent films.

[0017] Phosphors used in the preparation of fluorescent films typically come in colors such as red, green, and yellow. Technicians can adjust the ratio of phosphors to silica gel according to the light color requirements of the light source. The proportions and types of phosphors, as well as the proportion of silica gel, are modulated according to the desired light emission requirements. For example, if the fluorescent film is required to emit red light when excited by an LED chip, the proportion of red phosphor can be increased; if green light is required, the proportion of green light can be increased, and so on. For scenarios with lower color temperature requirements, the mass fraction of phosphor can generally be increased while the mass fraction of silica gel can be decreased; for scenarios with higher color temperature requirements, the mass fraction of phosphor can be decreased. In this way, by comprehensively considering the requirements for emission color, color temperature, and color rendering index, the type and proportion of phosphors are adjusted to obtain various mixtures with different ratios. Each ratio corresponds to a specific light emission requirement. The ratio for each light emission requirement in the required LED light source should be individually adjusted to meet that requirement in order to prepare the corresponding fluorescent film.

[0018] S02 uses a scraping method to mold mixtures of different proportions onto the surface of a release film to form corresponding fluorescent films.

[0019] The mixture is applied to the release film surface using a doctor blade on a film-forming machine to form an adhesive layer of a certain thickness. Mixtures with different proportions form on different release film surfaces and should not be mixed.

[0020] S03 pre-cures each fluorescent film to obtain multiple fluorescent films corresponding to different ratios of phosphors. The pre-curing state is achieved by reducing the baking time or baking temperature relative to the complete curing. The surface of the fluorescent film away from the release film has adhesiveness that can adhere to the LED chip.

[0021] Multiple fluorescent films can meet different light emission requirements, including color temperature, color rendering index, and RGB values. This means that the light emitted by LED chips after conversion from fluorescent films meeting different light emission requirements can have different color temperatures, color rendering indices, or RGB values. After applying adhesive, the fluorescent films are baked under certain conditions to achieve preliminary curing to a semi-cured state. The surface of the semi-cured fluorescent film (the surface away from the release film) is still tacky, but it has become adhesive and will not flow. Compared to the conditions for complete curing of ordinary fluorescent films, preliminary curing is usually achieved by reducing the baking time or temperature, such as baking at 130℃ for 0.5 hours. At this point, a fluorescent film with a tacky surface is obtained. It should be understood that the surface tackiness away from the release film is sufficient to adhere the LED chips, preventing them from easily falling off. Therefore, it can be used to arrange LED chips, which can be directly adhered to the surface of the fluorescent film without the need for additional adhesives or other materials for fixation. In this embodiment, each fluorescent film with different light emission requirements is prepared using this method. That is, the entire fluorescent film is in a semi-cured state before the LED chip is adhered, and it has the adhesiveness to adhere the LED chip.

[0022] After arranging the LED chips on the fluorescent film, the film is still in a semi-cured state, so it needs to be fully cured before cutting. This also includes: S11 completely cures the entire fluorescent film with multiple LED chips adhered to its surface. The entire fluorescent film with arranged and adhered LED chips is placed in an oven and baked at 150°C for 1 hour to completely cure the fluorescent film. At the same time, the LED chips are also firmly fixed to the surface of the fluorescent film. After the entire fluorescent film is completely cured, it is easy to separate from the release film. Since the release film has no adhesive properties, the fluorescent film is cut after peeling off the release film.

[0023] S30 cuts each fluorescent film along the gap between adjacent LED chips to obtain an LED structure containing a preset number of LED chips and having the same fluorescent film attached to its surface.

[0024] The purpose of this step is to obtain LED structures that meet different light-emitting requirements in an LED light source, and each LED structure already possesses the light-emitting function for a specific light-emitting requirement in the LED light source. The number of LED chips included in each LED structure is determined according to application requirements; it can include only one LED chip or multiple LED chips. The LED structure containing a preset number of LED chips with the same fluorescent film on their surfaces refers to an LED structure containing multiple LED chips, where the fluorescent films on the surfaces of the multiple LED chips come from the same fluorescent film. However, this step yields various types of LED structures, each with different light-emitting requirements for its fluorescent film. If the required LED light source has two light-emitting requirements, this step prepares LED structures that meet both requirements: one LED structure from the same fluorescent film (meeting one light-emitting requirement), and another LED structure from a different fluorescent film (meeting another light-emitting requirement).

[0025] During cutting, the release film is first peeled off, and simultaneously, a fully cured fluorescent film with multiple LED chips adhered to its surface is laid on the UV film surface. The UV film has a certain degree of adhesion, which can prevent the fluorescent film from cracking during cutting. After cutting, UV light is irradiated to peel the LED structure off the UV film. Figure 2 As shown, an LED structure contains only one LED chip. By cutting the fluorescent film 10 between adjacent LED chips 20, the LED structures are no longer bonded together by the fluorescent film, and each LED structure with a fluorescent film is independent. In multiple LED structures from the same fluorescent film, the photoelectric parameters of the LED chips used meet the same requirements, and the ratio of the fluorescent film is the same. Therefore, the luminous performance (including color temperature, color rendering index, RGB values, luminous intensity, etc.) of each LED structure can also meet the same photoelectric parameter requirements, such as color temperature being within the same color temperature range and color rendering index being within the same color rendering index range.

[0026] S40 arranges LED structures with different types of fluorescent films attached to them on the surface of the support film in a regular manner with the electrodes facing upwards, based on the light emission requirements of the LED light source.

[0027] The LED structures using different types of fluorescent films include at least two types of LED structures with two different fluorescent films attached. Each type of fluorescent film corresponds to one of the light emission requirements of the LED light source. The LED chip electrodes in the LED structure face upwards, and the fluorescent film is tightly attached to the surface of the support film. To prevent the LED structure from moving on the support film surface due to mechanical vibration or other factors, the support film used is a double-layer structure, consisting of a bottom UV film and a surface high-temperature resistant film. The high-temperature resistant film is used to adhere the LED structure arranged on the surface and can maintain its adhesion during subsequent baking, thus fixing the arrangement position of each LED structure. The UV film serves to support and fix the high-temperature resistant film, but its adhesion will fail due to high temperature during subsequent baking, so it cannot be directly used to adhere the LED structure.

[0028] The arrangement of the LED structures is designed according to the requirements of the LED light source product. Each LED light source is arranged as a unit, and within a unit, LED structures that meet different light emission requirements of the LED light source are simultaneously arranged. The LED structures are arranged regularly according to the different light emission requirements within the LED light source, such as the emission color. The gaps between LED structures within the same unit are kept as small as possible, just enough to fill with high-reflectivity white glue for isolation. To facilitate subsequent cutting, the gaps between different units can be appropriately increased. For example, when the LED light source is a square array, the LED structures should be arranged in a matrix; when the LED light source is a ring light source, the LED structures should be arranged in a ring array, and so on. In this embodiment, a matrix arrangement is used, with the matrix on the support film surface containing multiple unit arrays. Each unit array arranges LED structures according to the requirements of one LED light source. Furthermore, to make the LED light source emit light more uniformly, the LED structures of the fluorescent films that meet different light emission requirements are arranged alternately. That is, in adjacent LED structures, adjacent LED chip surfaces are fitted with fluorescent films that meet different light emission requirements, such as... Figure 3 and Figure 4 As shown, where, Figure 3 In this array, a dual-color temperature LED light source is a 2*2 unit array. Therefore, it adopts a method of alternating low color temperature fluorescent films and high color temperature fluorescent films in both the vertical and horizontal directions. Each 2*2 unit array contains a structure of four LEDs arranged diagonally. Figure 4 In this array, an RGBW light source is arranged in a 2x2 unit array, with each two rows forming a cycle. The first row consists of alternating LED structures with green fluorescent films and LED structures with red fluorescent films, while the second row consists of alternating LED structures with white fluorescent films and LED structures with blue fluorescent films. Each 2x2 unit array contains four RGBW LED structures.

[0029] In other embodiments, various arrangement methods can be adopted according to the actual needs of the LED light source, such as LED structures with the same row having the same light emission requirements, etc. This embodiment does not limit this.

[0030] S50 fills the gap between adjacent LED chips with high-reflectivity white glue, which at least covers the light-emitting side of the LED chip and the side of the fluorescent film.

[0031] There are gaps between the LED structures arranged on the surface of the support film. After the gaps between the LED structures are filled with high-reflectivity white glue, the sides of the fluorescent film, the sides of the LED chip, and the chip electrodes are covered. Then, it is sent into an oven and cured at high temperature for 2 hours in an oven at 150°C. During the curing process, a high-temperature resistant film is used to keep the position of the LED structure adhering to the film unchanged, ensuring that the arrangement of the LED structure is not affected by the high temperature. After curing, the LED structure on the entire support film is cured into one piece by high-reflectivity white glue.

[0032] The thickness of the high-reflectivity white adhesive should at least cover the light-emitting side and the side of the phosphor film of the LED chip, but should not exceed the upper surface of the LED chip electrodes. During fabrication, if the high-reflectivity white adhesive extends beyond the surface of the chip electrodes, the excess adhesive can be removed by physical grinding to expose the surface of the chip electrodes. Figure 5 As shown, the lower surface of the high-reflectivity white adhesive 30 is flush with the surface of the fluorescent film 10, and the upper surface of the high-reflectivity white adhesive is flush with the surface of the chip electrode in the LED chip 20. Thus, the high-reflectivity white adhesive covers the sides of the entire LED structure. By filling and curing with high-reflectivity white adhesive, the LED structures arranged on the same support film surface are fixed as a whole. Simultaneously, the high-reflectivity white adhesive also possesses reflective properties, isolating light between adjacent LED structures and preventing light crosstalk.

[0033] The white glue is a mixture of resin and light-reflecting particles. 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 light-reflecting particles are generally white inorganic pigments, such as oxides like titanium dioxide, zinc oxide, and zirconium oxide, lead white (lead carbonate), carbonates like calcium carbonate, clay minerals like kaolinite, etc., preferably titanium dioxide. These are doped into the resin at an appropriate concentration to give the high-reflectivity white glue a high reflectivity.

[0034] S60 cuts an LED light source into a unit and peels it off from the surface of the support film to complete the fabrication of the LED light source.

[0035] The number of LED chips in an LED light source can be set according to product requirements, such as 2 or 4 chips. The cutting rules are set according to the structure of the LED light source. Since the LEDs are already arranged as units with relatively large gaps between them to facilitate subsequent cutting, the cutting is performed along these gaps according to the arrangement rules. For example, if the LED light source has a 2x2 unit structure, then cutting is done every two columns and every two rows, resulting in an LED light source containing four LED chips.

[0036] After being cut and peeled off from the support film, the resulting LED light source contains LED structures that meet different light emission requirements. Regardless of the number of LED chips in the LED light source, the fluorescent films on the surface of the LED chips cannot only meet one type of light emission requirement; there must be at least two different types of fluorescent films. That is, an LED light source must have at least two fluorescent films that can respectively meet two light emission requirements. For example, for a dual-color temperature LED light source, there are high-color-temperature and low-color-temperature fluorescent films; for an RGBW mode LED light source, there are four different types of fluorescent films: red, green, blue, and white. Furthermore, to make the LED light source emit light more uniformly, the LED chips with fluorescent films meeting different light emission requirements are arranged alternately; that is, every two adjacent LED chip surfaces have fluorescent films meeting different light emission requirements.

[0037] In Example 1, a dual-color temperature LED light source is used as an example to describe the preparation method in detail: 11. Provide a first fluorescent film and a second fluorescent film with different color temperatures. The first fluorescent film is a single sheet of high color temperature fluorescent film, and the second fluorescent film is a single sheet of low color temperature fluorescent film. During the preparation of the fluorescent film, a release film is laid at the bottom, and a preliminary curing method is used. At this point, the surface of the resulting fluorescent film is adhesive, used to adhere the LED chip.

[0038] 12. Adhere the LED chips that meet the first light-emitting requirement to the surface of the first fluorescent film in a regular pattern. Adhere the LED chips that meet the second light-emitting requirement to the surface of the second fluorescent film in a regular pattern. At this stage, the LED chips adhered to the fluorescent film surface do not require a special arrangement; it is sufficient that the light-emitting surface of the LED chips is completely adhered. Simultaneously, the gaps between the LED chips should be as small as possible to fully utilize the fluorescent film. Then, completely cure the first and second fluorescent films, ensuring that the fluorescent films firmly adhere to the light-emitting surface of the LED chips during the curing process. After curing, the release film at the bottom can be removed.

[0039] 13. Cut the first fluorescent film and the second fluorescent film along the gap between adjacent LED chips. To prevent the fluorescent film from cracking during the cutting process, lay the entire fluorescent film with multiple LED chips adhered to its surface and fully cured on the UV film surface. After cutting, irradiate with UV light to remove the UV film. After cutting, multiple first LED structures (hereinafter referred to as low color temperature LED structures) with a first fluorescent film (low color temperature fluorescent film) attached to their surfaces and multiple second LED structures (hereinafter referred to as high color temperature LED structures) with a second fluorescent film (high color temperature fluorescent film) attached to their surfaces are obtained. At this point, the low color temperature LED structure and the high color temperature LED structure already possess the luminous performance of corresponding light colors. The low color temperature LED structure emits light with a relatively low color temperature after being powered on, and the high color temperature LED structure emits light with a relatively high color temperature after being powered on. The final LED light source includes at least one first LED structure and one second LED structure, enabling the LED light source to emit two color temperatures. Depending on the actual application needs, the LED light source can be designed to have one first LED structure and one second LED structure, or multiple first LED structures and multiple second LED structures, or a single first LED structure and multiple second LED structures, or multiple first LED structures and a single second LED structure, etc. For example, the LED light source in this example includes two first LED structures and two second LED structures.

[0040] 14. Using a method where each row of high color temperature LED structures alternates with low color temperature LED structures, and each column also alternates with high color temperature LED structures, the resulting low color temperature LED structures and high color temperature LED structures are arranged in a matrix on the surface of the support film (the support film consists of a UV film and a high-temperature resistant film on its surface). One dual-color temperature LED light source consists of 4 LED chips arranged in a 2*2 pattern. Therefore, the gap between every two LED chips in the horizontal and vertical arrangement is slightly larger to facilitate subsequent cutting.

[0041] 15. Inject high-reflectivity white glue onto the surface of the support film and cure it. The high-reflectivity white glue should at least cover the light-emitting side of the LED chip and the side of the fluorescent film.

[0042] 16. For areas with slightly larger gaps between two LED chips, cut every two columns and every two rows. The resulting LED light source comprises two first LED structures and two second LED structures, totaling four LED chips. This includes two low-color-temperature phosphor films and two high-color-temperature phosphor films positioned diagonally. Each row contains one low-color-temperature phosphor film and one high-color-temperature phosphor film. The resulting dual-color-temperature LED light source is then surface-mounted onto a conductive substrate. Driven by different circuits on the conductive substrate, it emits either low-color-temperature or high-color-temperature light, suitable for applications such as flashlights.

[0043] In Example 2, taking an RGBW structured LED light source as an example, the fabrication method is described in detail: 21. Provide a third, fourth, fifth, and sixth fluorescent film of different colors. The third fluorescent film is a single sheet of red fluorescent film, the fourth fluorescent film is a single sheet of green fluorescent film, the fifth fluorescent film is a single sheet of blue fluorescent film, and the sixth fluorescent film is a single sheet of white fluorescent film. During the preparation of the fluorescent films, a release film is laid at the bottom, and a preliminary curing method is used. At this stage, the surface of the resulting fluorescent film is adhesive, used to adhere the LED chip.

[0044] 22. Adhere the LED chips that meet the third light-emitting requirement to the surface of the third fluorescent film in a regular pattern. Adhere the LED chips that meet the fourth light-emitting requirement to the surface of the fourth fluorescent film in a regular pattern. Adhere the LED chips that meet the fifth light-emitting requirement to the surface of the fifth fluorescent film in a regular pattern. Adhere the LED chips that meet the sixth light-emitting requirement to the surface of the sixth fluorescent film in a regular pattern. At this stage, the LED chips do not need a special arrangement; as long as the light-emitting surface of the LED chips is completely adhered, it is acceptable. The gaps between the LED chips should be as small as possible to fully utilize the fluorescent film. Then, completely cure the third, fourth, fifth, and sixth fluorescent films, ensuring that the fluorescent films adhere firmly to the light-emitting surface of the LED chips during the curing process. After curing, the release film at the bottom can be removed.

[0045] 23. Cut the third, fourth, fifth, and sixth fluorescent films along the gaps between adjacent LED chips to form multiple third LED structures (red LED structures) with the third fluorescent film attached to their surfaces, a fourth LED structure (green LED structure) with the fourth fluorescent film attached to its surface, a fifth LED structure (blue LED structure) with the fifth fluorescent film attached to its surface, and a sixth LED structure (white LED structure) with the sixth fluorescent film attached to its surface. At this point, the red, green, blue, and white LED structures have the light-emitting performance of their corresponding colors and emit the red, green, blue, and white light required by the LED light source after applying voltage. To prevent the fluorescent films from cracking during the cutting process, lay a whole fluorescent film with multiple LED chips adhered to its surface and fully cured on the UV film surface. After cutting, remove the UV film by irradiating with UV light. The final LED light source includes at least one third LED structure, one fourth LED structure, one fifth LED structure, and one sixth LED structure, enabling the LED light source to emit four colors. Depending on the actual application requirements, the LED light source can be designed to have one third LED structure, one fourth LED structure, one fifth LED structure, and one sixth LED structure, or it can be designed to have multiple third LED structures, multiple fourth LED structures, multiple fifth LED structures, and multiple sixth LED structures, etc.

[0046] 24. An RGBW light source includes four LED chips arranged in a 2x2 pattern. Each pair of rows is defined as an arrangement unit. Within each unit, the first row uses alternating green and red LED structures, and the second row uses alternating white and blue LED structures, arranged in a matrix on the surface of a support film (the support film consists of a UV film and a high-temperature resistant film on its surface). Therefore, any 2x2 unit array contains four different types of LED structures: a third, a fourth, a fifth, and a sixth LED structure. Since an RGBW light source consists of four LED chips arranged in a 2x2 pattern, the gap between each pair of LED chips in both the horizontal and vertical arrangements is slightly larger to facilitate subsequent cutting.

[0047] 25. Inject high-reflectivity white glue onto the surface of the support film and cure it. The high-reflectivity white glue should at least cover the light-emitting side of the LED chip and the side of the fluorescent film.

[0048] 26. For areas with slightly larger gaps between two LED chips, cut every two columns and every two rows. The resulting LED light source contains a third, a fourth, a fifth, and a sixth LED structure, totaling four LED chips. Four different types of fluorescent films are attached to the surface of each LED chip: red, green, blue, and white. The resulting RGBW light source is then soldered onto a conductive substrate. Driven by different circuits on the substrate, it emits red, green, blue, or white light, respectively, and can be used in stage lighting, home lighting, and other fields.

[0049] In another embodiment of the present invention, an LED light source is prepared by the above-described preparation method. The LED light source contains multiple LED chips, each LED chip including a light-emitting surface, a chip side surface, and an electrode surface opposite to the light-emitting surface. Two chip electrodes are disposed on the electrode surface. Multiple fluorescent films are formed on the surfaces of the multiple LED chips. The multiple fluorescent films are prepared to meet different light-emitting requirements, and at least two different types of fluorescent films are respectively attached to different LED chip surfaces in the LED light source. High-reflectivity white adhesive is disposed at least around the light-emitting side surface of the LED chip, and the high-reflectivity white adhesive is filled between the different types of fluorescent films. Each type of fluorescent film corresponds to one light-emitting requirement in the LED light source. The number of LED chips in an LED light source can be set according to product requirements, with a minimum of 2 chips, and can be 2, 4, 5, etc. Regardless of the number of LED chips in an LED light source, the fluorescent film on the surface of the LED chips cannot only meet the same light emission requirement. There must be at least two different types of fluorescent films. That is, an LED light source must have at least two fluorescent films that can meet two light emission requirements respectively. For example, for a dual-color temperature LED light source, there are high color temperature fluorescent films and low color temperature fluorescent films. For an RGBW mode LED light source, there are fluorescent films with four emission colors: red fluorescent film, green fluorescent film, blue fluorescent film, and white fluorescent film.

[0050] There are several ways to arrange different types of fluorescent films in an LED light source: In one embodiment, each LED chip in the LED light source has a fluorescent film mounted on its surface that meets one light emission requirement, and adjacent LED chips have fluorescent films mounted on their surfaces that meet different light emission requirements. That is, different types of fluorescent films are arranged alternately in the LED light source, or the fluorescent films on the surface of each LED chip meet different light emission requirements. In another embodiment, the LED light source contains a large number of LED chips. Multiple LED chips in one part have fluorescent films mounted on their surfaces that meet the same light emission requirement, while multiple LED chips in another part have fluorescent films mounted on their surfaces that meet a different light emission requirement. The LED chips in these different parts are located in different areas. In practical applications, the arrangement can be based on the actual application requirements of the LED light source, and this embodiment does not impose any restrictions on this.

[0051] In one example, such as Figures 6-8 As shown, the LED light source 40 obtained after cutting contains four LED chips arranged in a 2*2 pattern. Each pair of adjacent LED chips has a fluorescent film attached to its surface to meet different light emission requirements, making it suitable for use in flashlights. Figure 6 and Figure 7 The dual-color temperature LED light source shown ( Figure 7 for Figure 6 (A cross-sectional schematic diagram), the light source contains four LED chips 20 arranged in a 2*2 pattern. Each of the four LED chips has an independent fluorescent film 10 attached. The spaces between the LED chips (including between the fluorescent films) are filled with white glue 30. High color temperature fluorescent films and low color temperature fluorescent films are arranged alternately, with fluorescent films requiring the same light emission positioned diagonally. Figure 8 The RGBW mode LED light source shown contains four LED chips arranged in a 2*2 pattern. Each of the four LED chips has a fluorescent film attached, and the fluorescent film on the surface of each LED chip emits a different color. That is, there are four fluorescent films with different colors of light emission: red fluorescent film, green fluorescent film, blue fluorescent film and white fluorescent film. It can be used in stage lighting, home lighting and other fields.

[0052] By soldering the aforementioned LED light source onto the surface of a conductive substrate, an LED lighting device is obtained, capable of emitting various types of light to meet different lighting requirements in response to current. In this LED lighting device, conductive lines on the surface of the conductive substrate drive the LED chips in the LED light source. Different lines drive LED chips that emit light according to different requirements; for example, line one controls all LED chips emitting light according to the first requirement, and line two controls all LED chips emitting light according to the second requirement. This allows LED chips meeting different lighting requirements to be independently controlled and driven, achieving flexible color adjustment. Technicians can design specific circuits according to product needs; this embodiment is not limited in its comparison. The conductive substrate includes printed circuit boards (PCBs), thin-film transistor (TFT) substrates, etc. Using surface mount technology, the LED light source is mounted onto the conductive substrate as a single unit, eliminating the need for individual mounting of each LED chip. This significantly reduces the gap between LED chips, which helps reduce the area occupied by the entire LED lighting device. Simultaneously, due to the reduced gap between adjacent LED chips, a uniform light spot can be formed more effectively during light mixing, providing a higher quality lighting effect.

[0053] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. 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 the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an LED light source, characterized in that, include: Provides multiple fluorescent films to meet different luminescence requirements; LED chips with the same light emission requirements are regularly adhered to the surface of the same fluorescent film; the LED chip includes a light-emitting top surface, a chip side surface, and an electrode surface opposite to the light-emitting top surface, and the LED chip is adhered to the surface of the fluorescent film through the light-emitting top surface; Each fluorescent film is cut along the gap between adjacent LED chips to obtain an LED structure containing a preset number of LED chips and having the same fluorescent film attached to its surface. Based on the light emission requirements of LED light sources, LED structures with different types of fluorescent films are arranged on the surface of the support film in a regular manner with the electrodes facing upward, taking one LED light source as a unit. High-reflectivity white glue is filled into the gap between adjacent LED chips, and the high-reflectivity white glue at least covers the light-emitting side and the side of the fluorescent film of the LED chip; The LED light source is obtained by cutting an LED light source unit and peeling it off from the surface of the support film, thus completing the fabrication of the LED light source.

2. The method for preparing an LED light source as described in claim 1, characterized in that, Among the multiple fluorescent films provided to meet different light emission requirements, a first fluorescent film and a second fluorescent film with different color temperatures are provided. The LED chips with the same light emission requirements are regularly adhered to the same fluorescent film surface, the LED chips that meet the first light emission requirement are regularly adhered to the first fluorescent film surface, and the LED chips that meet the second light emission requirement are regularly adhered to the second fluorescent film surface. The process of cutting each fluorescent film along the gap between adjacent LED chips to obtain an LED structure containing a preset number of LED chips and having the same fluorescent film attached to its surface includes obtaining a first LED structure with a first fluorescent film attached to its surface and a second LED structure with a second fluorescent film attached to its surface. Each LED structure includes at least one LED chip that meets the corresponding light emission requirement. The LED light source includes at least a first LED structure and a second LED structure.

3. The method for preparing an LED light source as described in claim 1, characterized in that, Among the multiple fluorescent films provided to meet different light emission requirements, a third fluorescent film, a fourth fluorescent film, a fifth fluorescent film, and a sixth fluorescent film with different colors are provided. The LED chips with the same light emission requirements are regularly adhered to the same fluorescent film surface, the LED chips that meet the third light emission requirement are regularly adhered to the third fluorescent film surface, the LED chips that meet the fourth light emission requirement are regularly adhered to the fourth fluorescent film surface, the LED chips that meet the fifth light emission requirement are regularly adhered to the fifth fluorescent film surface, and the LED chips that meet the sixth light emission requirement are regularly adhered to the sixth fluorescent film surface. The process of cutting each fluorescent film along the gap between adjacent LED chips to obtain an LED structure containing a preset number of LED chips and having the same fluorescent film attached to its surface includes obtaining a third LED structure with a third fluorescent film attached to its surface, a fourth LED structure with a fourth fluorescent film attached to its surface, a fifth LED structure with a fifth fluorescent film attached to its surface, and a sixth LED structure with a sixth fluorescent film attached to its surface. Each LED structure includes at least one LED chip that meets the corresponding light emission requirement. The LED light source includes at least a third LED structure, a fourth LED structure, a fifth LED structure, and a sixth LED structure.

4. The method for preparing an LED light source according to any one of claims 1-3, characterized in that, The LED chip is a flip-chip blue LED chip; The process involves regularly attaching LED chips with the same light emission requirements to the same fluorescent film surface, and regularly attaching flip-chip blue LED chips that meet the same light emission requirements to the same fluorescent film surface.

5. The method for preparing an LED light source as described in claim 2 or 3, characterized in that, Each LED structure contains only one LED chip; According to the light emission requirements of the LED light source, LED structures with different types of fluorescent films are arranged in a regular manner on the surface of the support film with the electrodes facing upward, taking one LED light source as a unit. Adjacent LED chip surfaces are fitted with fluorescent films that meet different light emission requirements.

6. The method for preparing an LED light source as described in claim 3, characterized in that, The LED light source includes four LED chips arranged in a 2*2 configuration.

7. The method for preparing an LED light source as described in claim 1, 2, 3, or 5, characterized in that, Prior to the step of providing multiple fluorescent films to meet different luminescence requirements, the following also includes: Different colored phosphors are uniformly mixed with silica gel in a certain proportion to obtain a variety of mixtures with different ratios, and the various different ratios correspond to the different light emission requirements of multiple fluorescent films; Mixtures with different proportions are molded onto the surface of release film by scraping adhesive to form corresponding fluorescent films; Each fluorescent film is initially cured to obtain multiple fluorescent films corresponding to different ratios of phosphors. The initial curing state is achieved by reducing the baking time or baking temperature compared to the state of complete curing. The surface of the fluorescent film away from the release film has adhesiveness that allows the LED chip to adhere.

8. The method for preparing an LED light source as described in claim 7, characterized in that, After the step of regularly attaching LED chips with the same light emission requirements to the surface of the same fluorescent film, the process further includes: completely curing the entire fluorescent film with multiple LED chips attached to its surface.

9. An LED light source, characterized in that, The LED light source is prepared by the preparation method according to any one of claims 1-8, and comprises: Multiple LED chips, each LED chip includes a light-emitting surface, a chip side, and an electrode surface opposite to the light-emitting surface; Multiple fluorescent films are formed on the surface of the multiple LED chips, and the multiple fluorescent films are prepared to meet different light emission requirements; The high-reflectivity white adhesive is at least surrounding the light-emitting side of the LED chip, and the high-reflectivity white adhesive is filled between different types of fluorescent films.

10. The LED light source as described in claim 9, characterized in that, In the LED light source, each LED chip surface is fitted with a fluorescent film that meets a light emission requirement, and adjacent LED chip surfaces are fitted with fluorescent films that meet different light emission requirements.

Images