LED light source

Abstract

The invention provides an LED light source. The LED light source comprises a substrate; the at least two LED chips are located on the substrate and used for generating exciting light, and the wavelengths of the exciting light generated by the at least two LED chips are different; the light conversion layers are located on the corresponding LED chips so as to receive the corresponding excitation light and generate output light, and the minimum excitation wavelength of light conversion materials in the light conversion layers is larger than the maximum wavelength of the corresponding excitation light; and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer and the maximum wavelength of the corresponding excitation light is less than 150 nm. The output light with the required color temperature can be generated by adjusting the internal parameters of the light conversion layer, and the LED light source with double color temperatures or multiple color temperatures can be simply and conveniently designed; meanwhile, the requirement of full spectrum can be met by integrating light conversion materials of various colors in each light conversion layer, the energy difference between the exciting light and the light conversion materials needing to be excited is small, energy waste can be avoided, and the lighting effect is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of LED lighting technology, and in particular to an LED light source. Background Art

[0002] Chip-on-Board (COB) light sources offer high light output efficiency and customizable design capabilities, particularly in applications such as dual-tone lighting and full-spectrum lighting. With the rapid development of LED technology and its widespread application in the lighting field, performance requirements for LED light sources are also increasing.

[0003] Existing COB dual-color full-spectrum light sources typically achieve full spectrum through either a common phosphor solution (LED chips stimulating multiple-color phosphors) or a three-blue light solution (three different wavelengths of blue LED chips mixed together). LED light sources made with common phosphor solutions often suffer from severe color loss, making it difficult to achieve a full spectrum. The three-blue light solution, on the other hand, samples a single wavelength, exhibiting peaks and valleys in the spectrum, resulting in a lack of spectral continuity. Furthermore, color temperature matching is extremely difficult to adjust, hindering LED light source performance and resulting in significant energy waste. Summary of the Invention

[0004] In view of this, the embodiments of the present application are dedicated to providing an LED light source to solve the problems of the existing technology such as difficulty in adjusting the color temperature of LED light sources, difficulty in achieving full spectrum effects, and high energy consumption.

[0005] On one hand, the present application provides an LED light source, comprising:

[0006] substrate;

[0007] at least two LED chips, located on the substrate, for generating excitation light, wherein the excitation light generated by the at least two LED chips has different wavelengths; and

[0008] At least two light conversion layers, each of which is located on a corresponding LED chip to receive corresponding excitation light and generate corresponding output light;

[0009] The minimum excitation wavelength of the light conversion material in the light conversion layer is greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer and the maximum wavelength of the corresponding excitation light is less than 150nm.

[0010] In some embodiments, the color temperatures of at least two of the output lights are different, and in the light conversion layer that produces the output lights of different color temperatures, the colors of the light conversion materials are not exactly the same; and / or, in the light conversion layer that produces the output lights of different color temperatures, the ratios of light conversion materials of different colors are not exactly the same.

[0011] In some embodiments, each of the light conversion layers comprises at least two light conversion materials of different colors, and the colors of the light conversion materials in at least two of the light conversion layers are completely different.

[0012] In some embodiments, all of the light converting layers have a total of red, orange, yellow, green, cyan, blue, and violet light converting materials.

[0013] In some embodiments, each of the light conversion layers has red, orange, yellow, green, cyan, blue, and violet light conversion materials.

[0014] In some embodiments, the LED chips are all purple LED chips, the light conversion layer on the purple LED chip with a wavelength less than or equal to 400nm has a dark blue light conversion material, and the light conversion layer on the purple LED chip with a wavelength greater than 400nm has a light conversion material of at least one color from red to dark blue.

[0015] In some embodiments, the LED chips are all blue light LED chips, and the light conversion layer on the blue light LED chip with a wavelength less than or equal to 450nm has a light conversion material of at least one color from yellow to dark blue, and the light conversion layer on the blue light LED chip with a wavelength greater than 450nm has a light conversion material of at least one color from red to yellow.

[0016] In some embodiments, the LED chips are all blue light LED chips, and the light conversion layer on the blue light LED chip with a wavelength of 400nm to 420nm has dark blue, light blue and cyan light conversion materials; the light conversion layer on the blue light LED chip with a wavelength of 420nm to 450nm has green and yellow light conversion materials; the light conversion layer on the blue light LED chip with a wavelength of 450nm to 470nm has yellow, orange and red light conversion materials; the light conversion layer on the blue light LED chip with a wavelength of 470nm to 500nm has orange and red light conversion materials.

[0017] In some embodiments, there is a gap between two adjacent LED chips, and the LED light source further comprises:

[0018] The light shielding layer is located in the gap.

[0019] In some embodiments, a difference between a minimum excitation wavelength of the light conversion material in the light conversion layer and a corresponding maximum wavelength of the excitation light is greater than 5 nm and less than 100 nm.

[0020] The present application provides an LED light source, comprising a substrate; at least two LED chips, located on the substrate, for generating excitation light, wherein the excitation light generated by at least two of the LED chips has different wavelengths; and at least two light conversion layers, wherein the light conversion layers are located on corresponding LED chips to receive corresponding excitation light and generate output light, wherein the minimum excitation wavelength of the light conversion material in the light conversion layer is greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer and the maximum wavelength of the corresponding excitation light is less than 150 nm. The present application forms a corresponding light conversion layer on each of the LED chips. By adjusting the internal parameters of the light conversion layer, the output light of the required color temperature can be generated. Combined with the series-parallel circuit design, it is possible to simply and conveniently design a dual-color temperature or multi-color temperature LED light source. At the same time, by integrating a variety of color light conversion materials in each of the light conversion layers, the full spectrum requirements can be met, making the spectrum of the LED light source full and rounded, close to the solar spectrum, solving the problems of the existing LED light source spectrum missing and insufficient spectrum continuity. Furthermore, in the present application, the wavelengths of the excitation light generated by at least two of the LED chips are different, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer and the corresponding maximum wavelength of the excitation light is less than 150nm, so that the energy difference between the excitation light and the light conversion material it needs to excite is not large, which is conducive to energy transfer, can avoid energy waste, and effectively improve light efficiency. In addition, the LED light source in the present application is simple to prepare and has high operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flowchart of a method for preparing an LED light source provided in one embodiment of the present application;

[0022] Figures 2 to 7 A schematic structural diagram corresponding to the corresponding steps of the method for preparing an LED light source provided in one embodiment of the present application;

[0023] Wherein, the accompanying drawings are marked as follows:

[0024] 100-substrate; 200-LED chip; 300-light conversion layer; 400-light shielding layer; 500-encapsulation adhesive layer. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] Figure 6This is a schematic diagram of the structure of an LED light source provided in one embodiment of the present application. Figure 7 FIG. 1 is a schematic diagram of the distribution of LED chips 200 on a substrate 100 according to an embodiment of the present application. Figure 6 and Figure 7 As shown, the LED light source may be a COB light source, which includes a substrate 100 , at least two LED chips 200 and at least two light conversion layers 300 .

[0027] Specifically, the substrate 100 can be a PCB, and its material can be ceramic materials (including AlN, Al2O3, SiO, SiO2, Si3N4, or SiON) or metal materials (including aluminum or copper). The substrate 100 is also a COB substrate, which can have at least two chip mounting areas. The chip mounting areas can be arranged in an array on the substrate 100. An LED chip 200 is die-bonded in each chip mounting area to emit corresponding excitation light.

[0028] In some embodiments, the LED chip 200 can be attached to the substrate 100 using die-bonding adhesive and then interconnected to pads on the substrate 100 using wires. In some embodiments, the LED chip 200 can also be flip-chip soldered to the substrate 100. This eliminates the constraints of wires and die-bonding adhesive, resulting in high thermal conductivity, low thermal resistance, and high current resistance for the LED chip 200, resulting in greater reliability, higher luminous flux maintenance, and longer service life.

[0029] In some embodiments, the excitation light emitted by the LED chip 200 can be blue light, purple light or ultraviolet light, etc. Based on this, the LED chip 200 can be a blue light LED chip, such as a GaN-based LED chip that emits blue light. The LED chip 200 can also be a purple light LED chip or an ultraviolet light LED chip.

[0030] Furthermore, the light conversion layer 300 corresponds to the LED chip 200 one-to-one, and each light conversion layer 300 is located on the corresponding LED chip 200 to receive the excitation light emitted by the corresponding LED chip 200 and generate the corresponding output light. Specifically, the light conversion layer 300 contains a light conversion material, which can absorb the excitation light generated by the corresponding LED chip 200 and generate light of the corresponding color, which is finally mixed to form the output light. For example, if the LED chip 200 is a blue light LED chip, the light conversion layer 300 can contain a red light conversion material and a green light conversion material. The red light conversion material and the green light conversion material generate red light and green light under the excitation of blue light. The red light, green light and blue light are finally mixed to form white light, which is the output light generated by the light conversion layer 300.

[0031] It should be noted that each light conversion layer 300 may contain only one color of light conversion material, or may contain at least two colors of light conversion materials. When the light conversion layer 300 contains only one color of light conversion material, the output light may be monochromatic. When designing an LED light source, it is necessary to mix multiple output lights so that the LED light source can produce white light.

[0032] The light conversion layer 300 in the present application can be made of a mixture of colloid and light conversion material. The light conversion material can be quantum dots or phosphors, and the colloid can be materials such as silica gel. That is, the light conversion layer 300 can be a quantum dot layer or a phosphor layer. When the light conversion material is quantum dots, the light conversion layer 300 is a quantum dot film, which can solve the problem that it is difficult to debug the glue ratio when the existing LED light source realizes dual color temperature or multi-color temperature. This is because in the conventional multi-color temperature glue dispensing method, it is necessary to first dispense the colloid of one circuit, and then dispense the colloid of another circuit. In the process of dispensing the colloids of the subsequent circuits, the colloids between different circuits will mix and affect each other, resulting in large color temperature errors and other problems, making debugging difficult. However, the use of quantum dot film mounting can effectively avoid the mutual influence between colloids during glue dispensing, making parameters such as color temperature more accurate and easier to debug.

[0033] In one embodiment of the present application, at least two output lights have different color temperatures, thereby forming a dual-color temperature or multi-color temperature LED light source. It should be understood that since each output light in the present application is generated by the excitation light emitted by the corresponding LED chip 200 stimulating the light conversion material in the corresponding light conversion layer 300, the output light of the desired color temperature can be generated by adjusting the internal parameters of the light conversion layer 300, making it simple and convenient to design a dual-color temperature or multi-color temperature LED light source.

[0034] Specifically, the color temperature of the light conversion layer 300 can be adjusted by adjusting the color of the light conversion material in the light conversion layer 300 (different colors also require different types of light conversion materials) and the ratio of the different color light conversion materials. This simplifies color temperature adjustment and improves operational efficiency. That is, in the light conversion layers 300 that generate output light of different color temperatures, the colors of the light conversion materials are not completely identical, and / or, in the light conversion layers 300 that generate output light of different color temperatures, the ratio of the different color light conversion materials is not completely identical. By adjusting at least one of the type of light conversion material and the ratio of the different color light conversion materials in each light conversion layer 300, the color temperature of the corresponding output light can be adjusted so that the color temperature of each output light meets the corresponding color temperature requirement. For example, the light conversion layer 300 may contain a red light conversion material and a green light conversion material. Increasing the red light conversion material or reducing the green light conversion material in the light conversion layer 300 can increase the color temperature, making the color temperature of the output light warmer; conversely, reducing the red light conversion material or increasing the green light conversion material in the light conversion layer 300 can reduce the color temperature, making the color temperature of the output light cooler; thus, by adjusting the ratio of the red light conversion material to the green light conversion material in the light conversion layer 300, the color temperature of the light conversion layer 300 can be conveniently adjusted so that the corresponding light conversion layer 300 meets the required color temperature requirements.

[0035] Of course, if the light conversion layer 300 contains light conversion materials of more colors, the output light is formed by mixing more colors of light. At this time, the color temperature adjustment of the output light will be more complicated, and the impact of the ratio of more colors of light conversion materials on the color temperature of the output light needs to be considered. Examples will not be given one by one here.

[0036] Furthermore, the present application can meet the requirements of the full spectrum by integrating light conversion materials of multiple colors in each light conversion layer 300 .

[0037] In some embodiments, each light conversion layer 300 contains at least two different colors of light conversion materials, and the colors of the light conversion materials in at least two light conversion layers 300 are completely different. Thus, all light conversion layers 300 contain at least four colors of light conversion materials, and the combination of at least two output lights can substantially meet the requirements of the full spectrum. Preferably, all light conversion layers 300 contain light conversion materials covering all colors of visible light (red, orange, yellow, green, cyan, blue, and violet), resulting in a full, rounded spectrum of the LED light source, close to the solar spectrum, and resolving the issues of missing or discontinuous spectrums in existing LED light sources.

[0038] In some embodiments, each light conversion layer 300 contains light conversion materials of all colors in the visible light (red, orange, yellow, green, cyan, blue, and purple). This can also make the spectrum of the LED light source full and round, close to the solar spectrum, and each output light can meet the requirements of the full spectrum, which can reduce the difficulty of design.

[0039] In some embodiments, the color temperatures of two adjacent output lights are different. Specifically, Figure 7 The LED chips 200 are arranged in rows and columns, and the light conversion layer 300 on each LED chip 200 generates corresponding output light. The color temperatures of two adjacent output lights in the row direction are different, and the color temperatures of two adjacent output lights in the column direction are also different, thereby improving the color temperature uniformity of the LED light source. For example, the LED light source is a dual-color temperature LED light source, which has two color temperatures, cold and warm. For each row of the light conversion layer 300 of the dual-color temperature LED light source, the output light generated is an alternating arrangement of cold color temperature output light and warm color temperature output light; for each column of the light conversion layer 300 of the dual-color temperature LED light source, the output light generated is also an alternating arrangement of cold color temperature output light and warm color temperature output light.

[0040] Of course, in order to improve the color temperature uniformity of the LED light source, the output lights of different color temperatures can also be distributed on the substrate 100 in other regularities, which will not be illustrated here one by one.

[0041] Furthermore, in some embodiments of the present application, at least two LED chips 200 generate excitation light of different wavelengths. The minimum excitation wavelength of the light conversion material in the light conversion layer 300 needs to be greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the corresponding excitation light is less than 150 nm. This ensures that the energy difference between the excitation light and the light conversion material to be excited is small, which facilitates energy transfer and avoids energy waste. For example, when the LED chips 200 are violet LED chips, some violet LED chips can emit short-wavelength excitation light, while other violet LED chips can emit medium- to long-wavelength excitation light. The wavelengths of excitation light generated by these two types of violet LED chips are different. For violet LED chips emitting short-wavelength excitation light, the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 disposed thereon and the maximum wavelength of its excitation light is less than 150 nm. For violet LED chips emitting medium-wavelength excitation light, the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 disposed thereon and the maximum wavelength of its excitation light is less than 150 nm.

[0042] Furthermore, to enable the excitation light to better excite the light conversion material in the light conversion layer 300, the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the corresponding excitation light can be greater than 5 nm. Furthermore, the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the corresponding excitation light can be less than 100 nm, thereby further shortening the energy difference between the excitation light and the light conversion material to be excited, further facilitating energy transfer.

[0043] Based on this, in some embodiments, the LED chips 200 can all be purple LED chips, and there are two types of purple LED chips, one is a purple LED chip with a wavelength less than or equal to 400nm (short-wavelength purple LED chip, emitting purple light in the 380nm to 400nm band as excitation light), and the other is a purple LED chip with a wavelength greater than 400nm (long-wavelength purple LED chip, emitting purple light in the 400nm to 450nm band as excitation light). In addition, the light conversion layer 300 on the purple LED chip with a wavelength less than or equal to 400nm contains a dark blue (wavelength of 450nm to 485nm) light conversion material, and the difference between the minimum excitation wavelength of the dark blue light conversion material and the maximum wavelength of the short-wavelength purple light is small. The energy of the short-wavelength purple light can be well transferred to the dark blue light conversion material, avoiding energy waste; the light conversion layer 300 on the purple LED chip with a wavelength greater than 400nm contains at least one color of red to light blue (red, orange, yellow, green, cyan, light blue (wavelength of 485nm to 500nm)). The difference between the minimum excitation wavelength of the red to light blue light conversion material and the maximum wavelength of the medium- and long-wavelength purple light is small. The energy of the medium- and long-wavelength purple light can be well transferred to the red to light blue light conversion material, avoiding energy waste. In this way, each color of light conversion material in the light conversion layer 300 can be effectively excited, and the energy difference between each excitation light and the light conversion material it needs to excite is small, which can avoid energy waste and improve the excitation efficiency and brightness of the LED light source.

[0044] In some embodiments, the LED chips 200 can also all be blue light LED chips, and there are two types of blue light LED chips, one is a blue light LED chip with a wavelength less than or equal to 450nm (short-wavelength blue light LED chip, emitting 400nm~450nm blue light as excitation light), and the other is a blue light LED chip with a wavelength greater than 450nm (long-wavelength blue light LED chip, emitting 450nm~500nm blue light as excitation light). Furthermore, the light conversion layer 300 on a blue LED chip with a wavelength less than or equal to 450nm contains a light conversion material of at least one color from yellow to dark blue (yellow, green, cyan, light blue, and dark blue). The difference between the minimum excitation wavelength of the yellow to dark blue light conversion material and the maximum wavelength of the short-wavelength blue light is small, so the energy of the short-wavelength blue light can be well transferred to the yellow to dark blue light conversion material, avoiding energy waste. The light conversion layer 300 on a blue LED chip with a wavelength greater than 450nm contains a light conversion material of at least one color from red to yellow (red, orange, and yellow). The difference between the minimum excitation wavelength of the red to yellow light conversion material and the maximum wavelength of the medium- and long-wavelength blue light is small, so the energy of the medium- and long-wavelength blue light can be well transferred to the red to yellow light conversion material, avoiding energy waste. In this way, each color of light conversion material in the light conversion layer 300 can be effectively excited, and the energy difference between each excitation light and the light conversion material it needs to excite is small, which can avoid energy waste and improve the excitation efficiency and brightness of the LED light source.

[0045] In some embodiments, the LED chips 200 can all be blue LED chips, and there are four types of blue LED chips: blue LED chips with wavelengths of 400nm to 420nm, blue LED chips with wavelengths of 420nm to 450nm, blue LED chips with wavelengths of 450nm to 470nm, and blue LED chips with wavelengths of 470nm to 500nm. Furthermore, the light conversion layer 300 on the blue LED chips with wavelengths of 400nm to 420nm contains dark blue, light blue, and cyan light conversion materials; the light conversion layer 300 on the blue LED chips with wavelengths of 420nm to 450nm contains green and yellow light conversion materials; the light conversion layer 300 on the blue LED chips with wavelengths of 450nm to 470nm contains yellow, orange, and red light conversion materials; and the light conversion layer 300 on the blue LED chips with wavelengths of 470nm to 500nm contains orange and red light conversion materials. In this way, each light conversion material is excited by the optimal excitation light, and the energy difference between each light conversion material and its corresponding excitation light is small, which can avoid energy waste and further improve the excitation efficiency and brightness of the LED light source.

[0046] It should be noted that the above-mentioned wavelength of the excitation light generated by the LED chip 200 and the light conversion material in the light conversion layer 300 are only examples. In fact, in order to meet the needs of the full spectrum, the light conversion material in the light conversion layer 300 usually has more colors. The present application designs at least two LED chips 200 for the LED light source. The wavelength of the excitation light emitted by each LED chip 200 is different. Then, a light conversion material that is more easily excited by its excitation light is set in the light conversion layer 300 on each LED chip 200, so that energy transfer between the excitation light and the corresponding light conversion material is easier to occur, thereby avoiding energy waste.

[0047] Please continue reading Figure 6 Adjacent LED chips 200 are not closely spaced together, but rather have a certain gap between them. That is, there is a gap between adjacent LED chips 200 in the row direction, and there is also a gap between adjacent LED chips 200 in the column direction. The LED light source also includes a light shielding layer 400, which is located within the gap. The light shielding layer 400 can block the excitation light emitted by the adjacent LED chips 200, preventing the excitation light emitted by the adjacent LED chips 200 from interfering with each other and solving the problem of optical crosstalk.

[0048] Furthermore, to achieve a light-shielding effect, the light-shielding layer 400 needs to be made of an opaque material. For example, the light-shielding layer 400 can be white. For example, the light-shielding layer 400 can be a white plastic layer. The white plastic layer can refract / reflect light, avoiding but not absorbing too much light, thereby avoiding energy waste. In some embodiments, the light-shielding layer 400 can also be other colors, such as black.

[0049] Furthermore, the top surface of the light-shielding layer 400 is not higher than the top surface of the LED chip 200. The top surface of the light-shielding layer 400 can be lower than the top surface of the LED chip 200 or flush with the top surface of the LED chip 200. This can avoid the light-shielding layer 400 from having an adverse effect on the output light, resulting in a decrease in the performance of the LED light source.

[0050] Please continue reading Figure 6 The LED light source also includes an encapsulation layer 500, which covers the light conversion layer 300, the light shielding layer 400, and the exposed substrate 100, thereby shielding the LED light source from the external environment and providing mechanical protection. Optionally, the encapsulation layer 500 can be made of a light-transmitting material such as UV adhesive, resin, silicone, or epoxy resin, without reducing the intensity of the output light.

[0051] Based on this, an embodiment of the present application further provides a method for preparing an LED light source. Figure 1 This is a flow chart of a method for preparing an LED light source according to an embodiment of the present application, as shown in FIG. Figure 1As shown, the preparation method of the LED light source includes:

[0052] Step S100: providing a substrate 100;

[0053] Step S200: die-bonding at least two LED chips 200 on the substrate 100, wherein the LED chips 200 are used to generate excitation light, and the excitation light generated by the at least two LED chips 200 has different wavelengths; and

[0054] Step S300: A light conversion layer 300 is formed on each LED chip 200, and the light conversion layer 300 is used to receive corresponding excitation light and generate corresponding output light. The minimum excitation wavelength of the light conversion material in the light conversion layer 300 is greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the corresponding excitation light is less than 150nm.

[0055] Figures 2 to 7 This is a schematic diagram of the structure corresponding to the corresponding steps of the method for preparing an LED light source provided in an embodiment of the present application. Figures 2 to 7 A method for preparing an LED light source provided in an embodiment of the present application is described in detail.

[0056] like Figure 2 As shown, step S100 is first performed to provide a substrate 100. Substrate 100 can be a PCB board, and its material can be selected from ceramic materials (including AlN, Al2O3, SiO, SiO2, Si3N4, or SiON) or metal materials (including aluminum or copper). Substrate 100 is also a COB substrate and can have at least two chip mounting areas, which can be arranged in an array on substrate 100.

[0057] Please continue reading Figure 2 , step S200 is performed to die-bond at least two LED chips 200 onto the substrate 100, with one LED chip 200 die-bonded onto one chip mounting area of ​​the substrate 100. Each LED chip 200 can be electrically connected to a pad within the corresponding chip mounting area using wires, or each LED chip 200 can be flip-chip soldered to the pad within the corresponding chip mounting area.

[0058] After the LED chips 200 are die-bonded on the substrate 100 , two adjacent LED chips 200 are not closely arranged together, but have a certain gap between them. That is, there is a gap between two adjacent LED chips 200 in the row direction, and there is also a gap between two adjacent LED chips 200 in the column direction.

[0059] like Figure 3As shown, a light shielding layer 400 is formed in each gap. Specifically, white glue can be applied in each gap. After the white glue is applied in each gap, the top surface of the white glue can be lower than the top surface of the LED chip 200 or can be flush with the top surface of the LED chip 200. Thereafter, the white glue is cured through a baking process, thereby forming the light shielding layer 400 in the gap.

[0060] In some embodiments, a precision dispensing process can be used to dispense white glue into the gap, and a fine needle can be used to accurately dispense liquid white glue into the gap. This method can accurately control the filling amount and position of the white glue, ensuring the thickness and uniformity of the white glue. The use of a fine needle helps to improve the accuracy and consistency of dispensing, especially when the gap is small.

[0061] like Figure 4 As shown, step S300 is performed to form a corresponding light conversion layer 300 on each LED chip 200. Specifically, the corresponding light conversion layer 300 can be first mounted on each LED chip 200, and then the light conversion layer 300 can be cured using a baking process. It should be noted that when mounting the light conversion layer 300 on each LED chip 200, the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the excitation light generated by the LED chip 200 must be less than 150nm.

[0062] like Figure 2 and Figure 5 As shown, in some embodiments, after the LED chips 200 are die-bonded onto the substrate 100, a corresponding light conversion layer 300 can be formed on each LED chip 200, and then a light shielding layer 400 can be formed in the gaps. In other words, the order of forming the light conversion layer 300 and the light shielding layer 400 can be reversed, which does not affect the implementation of the present application.

[0063] like Figure 6 and Figure 7 As shown, an encapsulation layer 500 is formed on the light conversion layer 300, the light shielding layer 400, and the exposed substrate 100. The encapsulation layer 500 is cured by a baking process. The encapsulation layer 500 effectively blocks the external environment and provides mechanical protection. Optionally, the encapsulation layer 500 can be made of a light-transmitting material such as UV adhesive, resin, silicone, or epoxy resin, so as not to reduce the intensity of the output light.

[0064] Afterwards you can Figure 6 The structure in the product is separated and packaged to form the final product.

[0065] It should be noted that the quantum dots referred to in this application are zero-dimensional semiconductor nanocrystals. When their particle size is less than a certain size, they will excite light of a specific wavelength in response to the size effect, thereby producing unique differences. The properties of quantum dots are mainly determined by factors such as size, defects, impurities, crystallinity, and passivation methods. These factors will affect the quantum efficiency and luminescence wavelength of quantum dots. When quantum dots are excited by external energy, electrons transition from the ground state to the excited state, giving the electrons and holes higher energy. The electrons and holes can then recombine and relax to a lower energy state, and finally return to the ground state. During the recombination and relaxation process, energy is released in the form of radiation (photons) or non-radiative means. The luminescence properties of quantum dots can be controlled by selecting the appropriate material and nanocrystal size. When the excitation energy received by a quantum dot exceeds its band gap, causing electrons to jump to the energy band, electrons in the conduction band and holes in the valence band can recombine to emit light. This direct recombination is called band-edge recombination, which also brings out the unique quantum confinement effect of quantum dots. Therefore, by varying the particle size of quantum dots, the band gap can be adjusted, thereby varying the wavelength of the emitted light. In optical applications, quantum dots made of the same material but with different particle sizes can be used to emit light of various wavelengths.

[0066] When defects exist in the quantum dot crystal structure or on its surface, after the quantum dot receives excitation energy, electrons and holes are captured by these defects and recombine from these defects, causing a shift in the emission wavelength. Therefore, the surface structure and defects of the quantum dot have a critical impact on the quantum dot's luminescence properties, and an appropriate surface state is essential for achieving high luminescence efficiency. Quantum dots have a large specific surface area, and the electronic quantum state and surface state have a significant impact on their optical properties. When quantum dots have a high specific surface area, the high surface energy state density may affect the quantum dot's optical absorption, quantum efficiency, luminescence intensity, spectral position, and fluorescence excitation. To improve the surface energy state, surface passivation is generally used to improve the optical properties of quantum dots. A common method of surface passivation is to coat the quantum dot surface with an organic or inorganic compound to completely passivate the unbonded structure on the quantum dot surface, eliminating the surface energy state and thus reducing the impact on the quantum dot's luminescence properties. Given that quantum dots can use a single material of different sizes and energy excitation to emit light of various wavelengths, and have various excellent characteristics such as high quantum efficiency, controllable emission wavelength, narrow half-wave width of the excitation light spectrum and wide wavelength of the excitation light, using quantum dots to replace phosphors has great advantages, and the present application can also effectively avoid the impact of the heat of the LED chip 200 on the service life of the quantum dots.

[0067] In summary, this embodiment provides an LED light source and a preparation method thereof, including a substrate 100; at least two LED chips 200, located on the substrate 100, for generating excitation light, and the wavelengths of the excitation light generated by at least two LED chips 200 are different; at least two light conversion layers 300, the light conversion layers 300 being located on the corresponding LED chips 200 to receive the corresponding excitation light and generate output light, the minimum excitation wavelength of the light conversion material in the light conversion layer 300 being greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the maximum wavelength of the corresponding excitation light being less than 150nm. In the present application, a corresponding light conversion layer 300 is formed on each LED chip 200. By adjusting the internal parameters of the light conversion layer 300, output light of the required color temperature can be generated, making it possible to simply and conveniently design a dual-color temperature or multi-color temperature LED light source. At the same time, by integrating multiple colors of light conversion materials in each light conversion layer 300, the full spectrum requirements can be met, making the spectrum of the LED light source full and rounded, close to the solar spectrum, solving the problems of spectrum loss and lack of spectrum continuity in existing LED light sources. Furthermore, in the present application, the wavelengths of the excitation light generated by at least two LED chips 200 are different, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer 300 and the corresponding maximum wavelength of the excitation light is less than 150nm, so that the energy difference between the excitation light and the light conversion material it needs to excite is not large, which is conducive to energy transfer and can avoid energy waste. In addition, the LED light source in the present application is simple to prepare and has high operating efficiency.

[0068] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. The systems disclosed in the embodiments are described briefly because they correspond to the methods disclosed in the embodiments. For relevant details, refer to the method description.

[0069] It should also be noted that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or to modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

[0070] It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0071] It should also be understood that the terms described herein are intended to describe particular embodiments only and are not intended to limit the scope of the invention. It should be noted that the singular forms "a" and "an" as used herein and in the appended claims include plural references unless the context clearly indicates otherwise. For example, a reference to "a step" or "a device" means a reference to one or more steps or devices, and may include secondary steps as well as secondary devices. All conjunctions used should be understood in their broadest sense. Also, the word "or" should be understood to have the definition of a logical "or" rather than a logical "exclusive or" unless the context clearly indicates otherwise. Furthermore, implementation of the methods and / or apparatus in embodiments of the present invention may include performing selected tasks manually, automatically, or in combination.

Claims

1. An LED light source, characterized in that: include: substrate(100); At least two LED chips (200) are located on the substrate (100) and are used to generate excitation light, wherein the excitation light generated by the at least two LED chips (200) has different wavelengths; as well as, at least two light conversion layers (300), the light conversion layers (300) being located on corresponding LED chips (200) to receive corresponding excitation light and generate corresponding output light; The minimum excitation wavelength of the light conversion material in the light conversion layer (300) is greater than the maximum wavelength of the corresponding excitation light, and the difference between the minimum excitation wavelength of the light conversion material in the light conversion layer (300) and the maximum wavelength of the corresponding excitation light is less than 150 nm.

2. The LED light source according to claim 1, characterized in that The color temperatures of at least two of the output lights are different; in the light conversion layer (300) that generates the output lights of different color temperatures, the colors of the light conversion materials are not completely the same; and / or, in the light conversion layer (300) that generates the output lights of different color temperatures, the proportions of the light conversion materials of different colors are not completely the same.

3. The LED light source according to claim 1, characterized in that Each of the light conversion layers (300) contains light conversion materials of at least two different colors, and the colors of the light conversion materials in at least two of the light conversion layers (300) are completely different.

4. The LED light source according to claim 3, characterized in that All the light conversion layers (300) contain red, orange, yellow, green, cyan, blue and violet light conversion materials in total.

5. The LED light source according to claim 1, characterized in that Each of the light conversion layers (300) contains red, orange, yellow, green, cyan, blue and purple light conversion materials.

6. The LED light source according to claim 1, characterized in that The LED chips (200) are all violet LED chips, the light conversion layer (300) on the violet LED chips with a wavelength less than or equal to 400 nm contains a dark blue light conversion material, and the light conversion layer (300) on the violet LED chips with a wavelength greater than 400 nm contains a light conversion material of at least one color from red to light blue.

7. The LED light source according to claim 1, characterized in that The LED chips (200) are all blue LED chips, and the light conversion layer (300) on the blue LED chips with a wavelength less than or equal to 450 nm contains a light conversion material of at least one color from yellow to dark blue, and the light conversion layer (300) on the blue LED chips with a wavelength greater than 450 nm contains a light conversion material of at least one color from red to yellow.

8. The LED light source according to claim 1, characterized in that The LED chips (200) are all blue LED chips, and the light conversion layer (300) on the blue LED chip with a wavelength of 400nm to 420nm contains dark blue, light blue and cyan light conversion materials; the light conversion layer (300) on the blue LED chip with a wavelength of 420nm to 450nm contains green and yellow light conversion materials; the light conversion layer (300) on the blue LED chip with a wavelength of 450nm to 470nm contains yellow, orange and red light conversion materials; and the light conversion layer (300) on the blue LED chip with a wavelength of 470nm to 500nm contains orange and red light conversion materials.

9. The LED light source according to claim 8, characterized in that: There is a gap between two adjacent LED chips (200), and the LED light source further comprises: The light shielding layer (400) is located in the gap.

10. The LED light source according to claim 1, characterized in that: The difference between the minimum excitation wavelength of the light conversion material in the light conversion layer (300) and the corresponding maximum wavelength of the excitation light is greater than 5 nm and less than 100 nm.

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