Center diffusion type distribution multi-core parallel COB flip four-color light source

Abstract

The utility model discloses a center diffusion type distribution multi-core parallel COB flip four-color light source, and belongs to the technical field of light source design. The light source comprises a red light chip, a green light chip, a blue light chip and a white light chip. The blue light chips are uniformly arranged in the middle; the green light chip and the red light chip are sequentially arranged on the periphery of the blue light chip in a surrounding manner to form an array structure in which the blue light chip, the green light chip and the red light chip are diffused layer by layer from the center to the periphery; the four groups of green light chips are respectively arranged at the upper, lower, left and right directions of the blue light chip array; six groups of red light chips are arranged; wherein two groups are respectively arranged above the upper green light chip and below the lower green light chip; the other four groups are respectively arranged above and below the green light chips in the left direction and the right direction; the white light chips are arranged on the periphery of the array structure formed by the red light chips, the green light chips and the blue light chips in a regular hexagon shape in a surrounding mode. According to the utility model, the problems of low color difference uniformity caused by non-uniform color mixing of the traditional LED and great reduction of color purity caused by excitation of fluorescent powder when the blue light is lightened can be solved.

Description

Technical Field

[0001] This utility model belongs to the field of light source design technology, specifically relating to a center-diffusion distributed multi-core parallel COB flip-chip four-color light source. Background Technology

[0002] The main structure of an LED includes the chip, package, and phosphor coating (for white LEDs). The chip is the core component of an LED, determining its emission color and efficiency. The package structure significantly impacts the LED's luminous efficiency, optical characteristics, and reliability; common package types include through-hole packaging and surface-mount packaging. White LEDs typically produce white light by coating a blue chip with yellow phosphor, mixing the blue light with the light emitted by the phosphor.

[0003] LED brackets require conductivity and heat dissipation. Metal is used to connect the LED chips to pads on the PCB board, enabling effective current injection. Simultaneously, some areas need insulation, necessitating the use of engineering plastics. Therefore, typical LED brackets are formed by metal stamping followed by injection molding. Different bracket materials are used for LEDs of varying power ratings: low-power LEDs generally use PPA, medium-power LEDs generally use PCT, and some high-power LEDs currently use EMC or ceramic substrate materials.

[0004] RGB LED beads on the market are generally made by electroplating copper, stamping it into the required size, and then injection molding it into a bracket. An RGB chip is then soldered into the bracket cup to make an RGB LED bead.

[0005] Compared to the TOP process, flip-chip COB uses an inverted chip mounting method, flipping the semiconductor chip electrode face down and using thermally conductive epoxy resin for bonding and fixing. Physical bonding between the substrate and the silicon wafer is achieved through heat treatment. After die bonding, micron-sized solder balls (such as the bumps of flip chips) are used to replace traditional gold wires, directly forming an electrical path between the chip electrode and the substrate, eliminating the lead bonding process. This technology belongs to the category of leadless die packaging. By shortening the physical distance between the electrode and the substrate, it significantly reduces the signal transmission distance, thereby improving high-frequency signal integrity and response speed.

[0006] Current technologies typically place RGB LEDs in the center of the bracket cup, using a multi-chip distribution in parallel or series connection. This technology has several problems: First, when illuminated with a lens for secondary optical color mixing, the goal is to emit a uniform cyan color, but in reality, one side tends to be bluer while the other greener, resulting in extremely poor color uniformity during RGB mixing, severely impacting visual effects and aesthetics. Second, the RGB and white light chips are not isolated. This design causes some white light chips to be activated when blue light is lit, significantly reducing the purity of the blue light, leading to uneven color and ineffective light spot effects. Third, existing COB-packaged multi-color LEDs are relatively large, which is insufficient for small-size applications. Fourth, existing low-voltage LEDs suffer from insufficient color rendering, a small beam angle per chip, and poor focusing and color uniformity, limiting their application in scenarios requiring high color uniformity. Utility Model Content

[0007] The present invention aims to at least partially solve one of the technical problems in the aforementioned related technologies.

[0008] Therefore, the purpose of this utility model is to provide a center-diffusion distributed multi-core parallel COB flip-chip four-color light source, which can solve the problems of uneven color mixing caused by traditional LEDs, resulting in low color uniformity and a significant reduction in color purity caused by the excitation of phosphors when blue light is lit.

[0009] To solve the above-mentioned technical problems, this utility model is implemented as follows:

[0010] This utility model embodiment provides a center-diffusion distributed multi-core parallel COB flip-chip four-color light source, the four-color light source including: red light chip, green light chip, blue light chip and white light chip;

[0011] The blue light chips are evenly arranged in the center;

[0012] The green light chip and the red light chip are arranged sequentially around the blue light chip, forming an array structure in which the blue light chip, green light chip and red light chip diffuse from the center to the periphery.

[0013] The white light chip is arranged in a regular hexagon around the array structure formed by the red light chip, green light chip and blue light chip.

[0014] In addition, the centrally diffused multi-core parallel COB flip-chip four-color light source of this utility model may also have the following additional technical features:

[0015] In some embodiments, the green light chips are in four groups, respectively located at the top, bottom, left, and right positions of the blue light chip array;

[0016] The red light chip consists of six groups; two groups are located above the upper green light chip and below the lower green light chip; the other four groups are located above and below the left and right green light chips respectively.

[0017] In some embodiments, the white light chip is in six groups, each located at one of the six corners of a regular hexagon.

[0018] In some implementations, the red light chip, the green light chip, the blue light chip, and the white light chip are all connected in parallel.

[0019] In some embodiments, white adhesive is provided between the array structure formed by the white light chip and the red light chip, green light chip and blue light chip.

[0020] In some embodiments, the four-color light source further includes a substrate, on which the red light chip, the green light chip, the blue light chip, and the white light chip are all disposed.

[0021] In some embodiments, a white adhesive insulating layer is provided between the substrate and the optical chip array.

[0022] In some of these embodiments, the substrate is a ceramic material or a high-conductivity BT material.

[0023] In some embodiments, the power of the four-color light source is 0.2-5W, and the size is 4.5mm*4.5mm to 5.0mm*5.0mm.

[0024] In some of these embodiments, there are four blue light chips arranged in a rectangular pattern;

[0025] There are 4 green light chips, and 6 red light chips and 6 white light chips.

[0026] In some of these implementations, a reflector cup structure is set on each chip by applying transparent adhesive.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] In this embodiment of the invention, the provided center-diffusion distributed multi-core parallel COB flip-chip four-color light source, through a unique chip arrangement, enables all chips to be lit when assembled with secondary optical lenses. When different color light chips are lit, the symmetrical distribution of the three primary colors breaks the periodic interference of the traditional linear arrangement, effectively eliminating moiré patterns and color gamut breaks. It can enable the spectral energy of adjacent pixels to be rapidly fused within a sub-millimeter distance, achieving color difference uniformity of ΔE<1.5 within the range of human eye perception.

[0029] In this embodiment of the utility model, the provided center-diffusion distributed multi-core parallel COB flip-chip four-color light source has the same light emission angle and color mixing state for each chip. When the color is mixed and lit, it greatly improves the uniformity of the light spot when the multi-color LED is lit by secondary optical color mixing, thus meeting the luminous efficacy requirements of the multi-color LED.

[0030] In this embodiment of the invention, the provided center-diffusion distributed multi-core parallel COB flip-chip four-color light source uses white glue to separate the RGB chip and the white light chip. The RGB chip is placed in the inner ring, the white light chip is placed in the outer ring, and the blue light chip is placed in the middle. The white glue isolates the blue light that can excite the phosphor. When the blue light is lit alone, it can prevent the blue light from exciting the phosphor on the white light chip to the greatest extent and can play a focusing role, significantly improving the color purity of the LED.

[0031] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an RGB chip arrangement structure disclosed in one embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the white chip arrangement structure disclosed in one embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the arrangement structure of the finished four-color light source disclosed in one embodiment of the present utility model;

[0035] Figure 4 This is a schematic diagram of the white adhesive setting according to one embodiment of the present utility model;

[0036] Figure 5 This is a schematic diagram of a 3D structure of a center-diffusion distributed multi-core parallel COB flip-chip four-color light source disclosed in one embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0038] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings, through specific examples and application scenarios.

[0039] Currently, traditional low-voltage multi-color LEDs typically place the RGB chips in the center and the white chips on either side of them. This arrangement leads to uneven light output when secondary optical mixing is applied using lenses. Specifically, when the blue and green chips are lit, according to the three primary color principle, ideally, blue light mixed with green light should produce a uniform cyan color. However, in reality, one side tends to be more blue than the other. This is due to the arrangement of the blue and green chips. The same applies to other chips emitting uneven light after mixing. White LEDs emit light through a combination of a blue chip and yellow phosphor. Blue light has high energy; the blue light emitted by the blue chip is excited by the yellow phosphor to produce yellow light, which mixes with the blue light to form white light. In existing traditional multi-color LED chips, the blue and white chips are not separated. This causes the phosphors on some of the white chips surrounding the blue chip to be excited when the blue light is lit alone, emitting a small amount of white light, thus reducing the color purity of the LED. Furthermore, because only a portion of the white light chip is excited, the uniformity of light emission from the blue light chip is low, failing to reach the ideal state. Currently, low-voltage COB packaged multicolor LED chips on the market are relatively large, which cannot meet the market's demand for small-sized LED chips.

[0040] To solve these major problems, this invention first changes the traditional arrangement of multi-color LED chips, placing four blue LED chips in the exact center of the substrate, such as... Figure 1 As shown, four green LED chips are arranged in a surrounding pattern, with the blue LED chip positioned above, below, to the left, and to the right of it. Then, six red LED chips are arranged with two chips above and below the green LED chip, and two chips on each side, sandwiching the green LED chips in the middle. Six white LED chips are arranged in a regular hexagonal pattern, with one white LED chip placed at each vertex, centered on the red, green, and blue LED chips. Figure 2 and Figure 3 As shown. This chip arrangement allows all chips, when illuminated with secondary optical lenses, to break the periodic interference of traditional linear arrangements through symmetrical distribution of the three primary colors, effectively eliminating moiré patterns and color gamut breaks. This design enables the rapid fusion of spectral energy between adjacent pixels within a sub-millimeter distance, achieving color difference uniformity of ΔE < 1.5 within the range of human visual perception.

[0041] In the above embodiments, the emission angle and color mixing state of each chip are consistent. When the multi-color LED is lit up by color mixing, the uniformity of the light spot is greatly improved, which meets the luminous efficacy requirements of the multi-color LED.

[0042] Secondly, to address the issue of phosphor excitation when the blue LED chip is lit, this invention uses white adhesive to separate the RGB and white LED chips. The RGB chip is placed in the inner ring, the white LED chip in the outer ring, and the blue LED chip in the center. The white adhesive isolates the blue light that excites the phosphor. When the blue LED is lit alone, it minimizes the excitation of the phosphor on the white LED chip and acts as a light-focusing agent, significantly improving the color purity of the LED. Figure 4 As shown.

[0043] This invention then employs a COB multi-core parallel connection of blue, green, red, and white light chips, and connects each chip together using a flip-chip method, such as... Figure 3 As shown. The flip-chip structure reduces the risk of failure due to bonding wire vibration or breakage. The active surface of the chip is directly connected to the substrate through bumps, resulting in a shorter heat conduction path and better heat dissipation efficiency than traditional packaging. This is beneficial for the stable operation of high-power chips, significantly improves interconnect density, saves packaging area, and meets the requirements of high performance and high integration, thus realizing small-size COB packaged LEDs. Furthermore, a multi-layer alumina or aluminum nitride ceramic substrate or a high-conductivity BT material substrate is used, and a multi-layer wiring process is designed, which omits the complex wire bonding process compared to the traditional upright chip method. The entire product design uses COB multi-core parallel connection of chips of different sizes, and the size of the designed finished product is between 4.5mm*4.5mm and 5.0mm*5.0mm, with a design voltage of 3V. This small-size LED design meets the market demand for low-voltage small-size COB packaging and has better light focusing effect in secondary optics.

[0044] Finally, the above design scheme solves the problems of uneven color mixing in traditional LEDs, resulting in poor color uniformity and a significant reduction in color purity caused by phosphor excitation when blue light is applied. It employs alumina or aluminum nitride ceramic substrates or high-conductivity BT material substrates with all flip-chip technology. Through optical microstructure recombination, a dynamic balance is achieved between the dielectric constant of the ceramic substrate and the thermal expansion coefficient of the metal circuitry, avoiding the luminous efficacy degradation caused by material mismatch in traditional multi-color LEDs. This new design approach not only improves the performance and effect of LEDs but also expands their design beyond the traditional mindset of multi-color LED design. It shifts from single luminous efficacy optimization to a multi-dimensional design paradigm integrating optical structures, miniaturized packaging, and adaptive driving, driving the evolution of LED products towards high-performance system solutions.

[0045] In some embodiments of this invention, ceramic materials are used as the main substrate material. Ceramic materials (such as alumina and aluminum nitride) have high thermal conductivity and excellent insulation properties, which can quickly dissipate the heat generated by the LED chip and ensure circuit safety. Since white objects can reflect all visible light, they have high reflectivity for all wavelengths of light and low absorption for all wavelengths of light. Therefore, this invention coats the surface with a layer of white glue to enhance reflected light, making the LED brighter. Secondly, this invention changes the traditional arrangement of multi-color LED chips, placing the blue chip in the center, with green chips arranged around it. Similarly, red and white chips are also arranged in the same way. A filling process is used to create an insulating wall in the circular area between the white LED chip and the RGB LED chip using white glue. White glue, being a white material, reflects all visible light. This design reduces light scattering and waste, reflects the side light emitted by the RGB chip, and improves the brightness of the RGB LED. When the blue LED is lit alone, because blue light has high energy, the blue light emitted by the blue LED is excited by the yellow phosphor, producing yellow light, which mixes with the blue light to form white light, reducing the color purity of the blue light. The white glue isolates the blue light that can excite the phosphor from the phosphor on the white LED chip. When the blue light is lit alone, it minimizes the possibility of the blue light exciting the phosphor on the white LED chip, improving the color purity of the LED when the blue light is lit alone and the overall brightness of the RGB LED.

[0046] Finally, a layer of transparent adhesive is applied to the center of each chip. This adhesive not only protects the chip but also creates a smooth and glossy reflector structure on top of the RGB chip, resembling a smooth bowl. This reflector structure can control the distance and area of ​​light emitted by the RGB chip by reflecting the light, allowing the light to shine farther and brighter. It can significantly improve the efficiency of light utilization, reduce light scattering and waste, thereby enhancing the overall lighting effect and increasing the brightness of the RGB.

[0047] The above design utilizes a centrally diffused, multi-core parallel COB flip-chip four-color light source. This involves parallel COB connections of blue, green, red, and white LED chips, with each chip connected together using a flip-chip configuration. Figure 5 As shown. This saves packaging area, meets the demands for high performance and high integration, and thus enables small-size COB packaged LEDs. It also satisfies the market's requirements for uniformity in secondary optics of low-voltage, small-size LED chips, improving LED performance and effect.

[0048] Any part of this utility model that is not described in detail can be referred to the prior art or the art known to those skilled in the art. This embodiment does not limit this and will not describe it in detail here.

[0049] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A center-diffusion distributed multi-core parallel COB flip-chip four-color light source, characterized in that, The four-color light source includes: a red light chip, a green light chip, a blue light chip, and a white light chip; The blue light chips are evenly arranged in the center; The green light chip and the red light chip are arranged sequentially around the blue light chip, forming an array structure in which the blue light chip, green light chip and red light chip diffuse from the center to the periphery. The white light chip is arranged in a regular hexagon around the array structure formed by the red light chip, green light chip and blue light chip.

2. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The green light chips are in four groups, respectively located at the top, bottom, left, and right positions of the blue light chip array; The red light chip consists of six groups; two groups are located above the upper green light chip and below the lower green light chip; the other four groups are located above and below the left and right green light chips respectively.

3. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The white light chips are in six groups, each located at one of the six corners of a regular hexagon.

4. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The red light chip, the green light chip, the blue light chip, and the white light chip are all connected in parallel.

5. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The array structure formed by the white light chip, red light chip, green light chip, and blue light chip is separated by white adhesive.

6. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The four-color light source also includes a substrate, and the red light chip, the green light chip, the blue light chip and the white light chip are all disposed on the substrate.

7. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 6, characterized in that, A white adhesive insulating layer is provided between the substrate and the optical chip array.

8. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 6, characterized in that, The substrate is made of ceramic material or high-conductivity BT material.

9. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The power of the four-color light source is 0.2-5W, and the size is 4.5mm*4.5mm to 5.0mm*5.0mm.

10. The center-diffusion distributed multi-core parallel COB flip-chip four-color light source according to claim 1, characterized in that, The blue light chips consist of four chips arranged in a rectangular pattern. There are 4 green light chips, and 6 red light chips and 6 white light chips.

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