Dot matrix imaging COB light source and COB high-power display light emitting device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FOSHAN EVERCORE OPTOELECTRONICS TECH
- Filing Date
- 2025-07-10
- Publication Date
- 2026-06-26
Smart Images
Figure CN224419210U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of COB light sources, and in particular to a dot matrix imaging COB light source and a high-power COB display light-emitting device. Background Technology
[0002] In the field of projection display, high brightness and high resolution display technology have always been the industry's pursuit. High-end technology products such as Tesla pixel array headlights and Silan Micro pixel array headlight modules, with their advanced pixel control and optical systems, achieve high-precision light projection and rich display effects. These technologies, through complex chip integration solutions, precision optical components, and high-performance drive systems, achieve high brightness and small-pitch display performance, and are widely used in scenarios with extremely high display quality requirements. However, such high-end technologies have extremely stringent requirements for manufacturing processes and materials, involving complex technologies such as nanoscale optical calibration and high-precision drive chip design. The technical threshold is extremely high, and the high manufacturing costs keep the prices of related products high, making it difficult to promote and apply them in cost-sensitive markets such as low-end projectors.
[0003] Currently, the demand for display products in the low-end projection market is growing rapidly. Traditional projection display technology, due to its use of conventional light sources and display methods, suffers from problems such as insufficient brightness, large pixel pitch, and low display accuracy, making it difficult to meet users' demands for clear and bright projected images. In addition, existing low-end projection products lag far behind high-end products in terms of display quality, failing to provide users with a good visual experience, and current technological solutions have consistently struggled to achieve a balance between performance and cost.
[0004] Therefore, developing a projection display technology that can achieve display effects similar to high-end products while significantly reducing costs has become a new research direction. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a dot matrix imaging COB light source with high power, high brightness, small spacing between light-emitting points, and low cost.
[0006] The technical problem to be solved by this utility model is to provide a COB high-power display light-emitting device with high brightness, small light-emitting point spacing and uniform light emission, which has the potential to fill the market gap in low- and mid-range projection products.
[0007] To solve the above-mentioned technical problems, the first aspect of this utility model provides a dot matrix imaging COB light source, including a substrate and a COB dot matrix packaged on the substrate in a COB manner.
[0008] The COB dot matrix includes light-emitting chips arranged in rows and columns. The first electrode of all the light-emitting chips in each row is connected to the corresponding row pin, and the second electrode of all the light-emitting chips in each column is connected to the corresponding column pin.
[0009] As an improvement to the above solution, the light-emitting chip is electrically connected to the substrate via bonding wires, and the tail end of the bonding wires bonded to the light-emitting chips in each column is connected to the head end of the bonding wires bonded to the adjacent light-emitting chips.
[0010] As an improvement to the above solution, a dam is also provided on the substrate. The dam includes a first dam and a second dam. The first dam is arranged around the COB dot matrix, and the second dam is arranged in the gap between the light-emitting chips arranged in rows and columns.
[0011] As an improvement to the above solution, the second dam includes a first dam protruding from the substrate and a second dam covering the first dam, wherein the second dam covers a portion of the bonding wire.
[0012] As an improvement to the above solution, the height of the first layer of dam after solidification is not higher than the height of the light-emitting chip; the height of the second layer of dam is higher than the height of the light-emitting chip.
[0013] As an improvement to the above scheme, the first layer of the dam is a dam formed by white wall adhesive, or the first layer of the dam is a dam formed by dam adhesive.
[0014] The second layer of the dam is a dam formed by dam adhesive.
[0015] As an improvement to the above solution, the light-emitting chips in the COB dot matrix are closely arranged on the substrate, and the distance between two adjacent light-emitting chips in the horizontal direction is less than 1 mm.
[0016] In the vertical direction, the spacing between two adjacent light-emitting chips is less than 1 mm.
[0017] As an improvement to the above solution, the substrate is one or more of copper substrate, aluminum substrate, and ceramic substrate;
[0018] The COB dot matrix is an 8x8 array;
[0019] The COB dot matrix can be a monochrome COB dot matrix, a two-color COB dot matrix, or a full-color COB dot matrix.
[0020] As an improvement to the above scheme, the area formed by the first dam is also filled with a fluorescent adhesive layer covering the light-emitting chip.
[0021] The second aspect of this utility model also provides a high-power COB display light-emitting device, including the aforementioned dot matrix imaging COB light source.
[0022] Implementing this utility model has the following beneficial effects:
[0023] In this invention, the COB dot matrix is packaged on the substrate in a COB manner, ensuring the light-emitting area of the COB dot matrix. Simultaneously, the first electrodes of all light-emitting chips in each row are shared and connected to the corresponding row pins, and the second electrodes of all light-emitting chips in each column are shared and connected to the corresponding column pins. Special wire bonding is performed between the multiple light-emitting chips. By controlling the signals of each row and each column, the light emission control of each light-emitting chip in the COB dot matrix can be achieved, thereby realizing high-precision light projection and rich display effects. Furthermore, centralized wiring significantly reduces circuit complexity, lowers resistance loss, and shortens the spacing between adjacent light-emitting chips, thereby improving power efficiency and brightness, achieving higher pixel density, and lower cost, meeting the market demand for mid-to-low-end projection products. Attached Figure Description
[0024] Figure 1 : A schematic diagram of the structure of a dot matrix imaging COB light source in this utility model;
[0025] Figure 2 : Circuit connection diagram of COB dot matrix in this utility model.
[0026] Figure label:
[0027] 1-Substrate; 2-COB matrix; 21-Light-emitting chip; 22-Row pin; 23-Column pin; 3-First dam; 4-Second dam; 41-First layer dam; 42-Second layer dam; 5-Bond wire; 6-Fluorescent adhesive layer. Detailed Implementation
[0028] To make the objectives, technical solutions and advantages of this utility model clearer, specific embodiments will be described in further detail below.
[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.
[0030] In the description of this application, it is necessary to understand that the orientation or positional relationship indicated by terms such as "upper", "lower", "top", "bottom", "inner", and "outer" are based on the orientation or positional relationship shown in the accompanying drawings. The purpose is only to facilitate the description of this utility model and simplify the description, and is not intended to indicate or imply that the component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.
[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0032] In existing technologies, LED dot matrix technology, with its clear character and image display capabilities, is commonly used in information display, signage, and other fields. However, the light emission mode of LED high-power display devices using LED dot matrix light sources is prone to color spots, poor color uniformity, and limited dot pitch, making it difficult to adapt to high-resolution projection requirements, and also resulting in high maintenance costs. COB (Chip On Board) light sources, on the other hand, have advantages such as high integration and uniform light emission. Directly applying the dot matrix display technology of high-power LED display devices to prepare dot matrix imaging COB light sources has become a new research approach. However, the packaging processes of the two differ. The chip layout and packaging method of COB light sources focus on overall light emission uniformity and stability, lacking the fine layout and control capabilities specifically for dot matrix displays, making it difficult to directly meet the high-precision display requirements of applications such as projection. If a similar dot matrix display effect is achieved using conventional COB packaging methods, not only will the image be blurred due to excessively large dot pitch, but also, during high-power operation, insufficient thermal conductivity of the substrate will easily lead to heat accumulation, causing accelerated light decay and shortened device lifespan.
[0033] To resolve the above issues, please refer to [link / reference]. Figure 1 The first aspect of this utility model provides a dot matrix imaging COB light source, including a substrate 1 and a COB dot matrix 2 encapsulated on the substrate 1 in a COB manner.
[0034] Please see Figure 2The COB dot matrix 2 includes light-emitting chips 21 arranged in rows and columns. The first electrode of all the light-emitting chips 21 in each row is connected to the corresponding row pin 22, and the second electrode of all the light-emitting chips 21 in each column is connected to the corresponding column pin 23. It can be understood that the first electrode can be an anode, with all the light chips 21 in each row being configured as a common anode, and the second electrode can be a cathode, with all the light chips 21 in each column being configured as a common cathode.
[0035] In this invention, the COB dot matrix 2 is packaged on the substrate 1 in a COB manner, ensuring the light-emitting area of the COB dot matrix 2. Simultaneously, the first electrodes of all light-emitting chips 21 in each row are shared and connected to the corresponding row pin 22, and the second electrodes of all light-emitting chips 21 in each column are shared and connected to the corresponding column pin 23. Special wire bonding is performed between the multiple light-emitting chips 21. By controlling the signals of each row and each column, the light emission control of each light-emitting chip 21 in the COB dot matrix 2 can be achieved, thereby realizing high-precision light projection and rich display effects. Furthermore, centralized wiring significantly reduces circuit complexity, lowers resistance loss, and shortens the spacing between adjacent light-emitting chips 21, thereby improving power efficiency and brightness, achieving higher pixel density, and lower cost, meeting the market demand for mid-to-low-end projection products.
[0036] Preferably, the shape design of the COB dot matrix 2 can be reasonably optimized by comprehensively considering requirements such as projection imaging, light uniformity, heat dissipation path, manufacturing difficulty, and cost. More preferably, the COB dot matrix 2 is one of a square array or a circular array, and the square shape includes, but is not limited to, squares, rectangles, hexagons, etc.
[0037] The following explanation uses an 8x8 square COB matrix with the first electrode as the anode and the second electrode as the cathode as an example.
[0038] Specifically, the light-emitting chip 21 is electrically connected to the substrate 1 via bonding wire 5. The anodes of the light-emitting chips 21 in each row are connected in parallel via individual bonding wires 5 to form row pins a, b, c, d, e, f, g, h. The cathodes of the light-emitting chips 21 in each column are connected in parallel to form column pins 1, 2, 3, 4, 5, 6, 7, 8. When row pin ah and column pins 1-8 are all turned on simultaneously, the entire COB dot matrix 2 emits light simultaneously. When row pin a is turned on and column pins 1-8 are turned on simultaneously, all the light-emitting chips 21 in the first row can light up simultaneously. By turning off row pin a and then turning on row pin bh in sequence, all the light-emitting chips 21 in the second to eighth rows can light up sequentially. Alternatively, by turning off column pin 1 and then turning on column pins 2-8 in sequence, all the light-emitting chips 21 in the second to eighth columns can light up sequentially, forming an array display. If pin a is simultaneously connected to pin 1 in the same row, only the light-emitting chip 21 located in the first row and first column can be illuminated, thus achieving illumination control of a single light-emitting chip 21 and thereby realizing the display effect of a specific pattern. It is understood that the bonding wire 5 includes, but is not limited to, gold wire.
[0039] More preferably, the tail end of the bonding wire 5 welded to the light-emitting chip 21 in each column is connected to the head end of the bonding wire 5 welded to the adjacent light-emitting chip 21. Taking an aluminum substrate as an example, aluminum substrates are generally single-sided, while double-layer aluminum substrates are relatively expensive. By setting suspended bonding wires 5 vertically on a conventional single-sided substrate, intersections with the aluminum substrate's lines can be avoided, ensuring the stability of the bonding wires 5 while reducing costs. Furthermore, the high thermal conductivity of the aluminum substrate can be utilized to fabricate high-power display light-emitting devices.
[0040] Optionally, the COB dot matrix 2 can be a monochrome COB dot matrix, a dual-color COB dot matrix, or a full-color COB dot matrix, and the light-emitting chip 21 can be one or more of red, green, and blue light-emitting chips. The size and luminous performance of the light-emitting chip 21 can be reasonably selected according to specific circumstances.
[0041] Furthermore, in the COB matrix 2, the light-emitting chips 21 are closely arranged on the substrate 1. However, directly and densely arranging a large number of light-emitting chips 21 on the substrate 1 results in a high heat flux density, causing heat to accumulate rapidly in a small area. If heat cannot be dissipated quickly, the junction temperature will rise rapidly, leading to light decay. Therefore, in this application, the spacing between adjacent light-emitting chips 21 in the COB matrix 2 is strictly adjusted, and the heat dissipation performance of the substrate 1 is controlled to improve the heat dissipation problem.
[0042] Preferably, the spacing between two adjacent light-emitting chips 21 is less than 1 mm in the horizontal direction and less than 1 mm in the vertical direction. In this configuration, the light-emitting chips 21 in both the vertical and horizontal directions cooperate with each other, and the gap between adjacent chips 21 can serve as a heat dissipation channel, improving heat dissipation efficiency. Furthermore, a suitable spacing can form a continuous light spot, improving the brightness uniformity of the dot matrix imaging COB light source, while reducing light interference between adjacent chips, ensuring color purity, and increasing contrast. If the spacing between two adjacent light-emitting chips 21 is too large, it will cause discontinuous light spots, affecting the smoothness of the projected image. If the spacing between two adjacent light-emitting chips 21 is too small, it may cause light field overlap, reducing contrast and heat dissipation efficiency. It should be noted that the spacing between two adjacent light-emitting chips 21 here refers to the distance between the edge of one light-emitting chip 21 and the edge of the adjacent light-emitting chip 21.
[0043] Existing display technology solutions on the market struggle to balance cost control and performance improvement. While using a substrate with high thermal conductivity can improve heat dissipation, it significantly increases material costs. Optimizing the packaging process can reduce the pitch of light-emitting dots, but the increased process complexity leads to reduced production efficiency and higher costs, making it difficult to meet the dual demands of high brightness and low cost for low-end projection products.
[0044] Furthermore, the substrate 1 can be selected with a high thermal conductivity. In this case, the substrate 1 has sufficient mechanical strength to prevent deformation that could lead to welding failure of the light-emitting chip 21. Moreover, the high thermal conductivity of the substrate 1 results in a more uniform heat distribution, high heat dissipation efficiency, and reduced light spot shift caused by uneven thermal expansion, while effectively controlling costs. Exemplarily, the substrate 1 is one or more of a copper substrate, an aluminum substrate, and a ceramic substrate, wherein the aluminum substrate 1 includes a mirror-finished aluminum substrate; more preferably, the substrate 1 is an aluminum substrate.
[0045] Please see Figure 1 The substrate 1 is further provided with dams, including a first dam 3 and a second dam 4. The first dam 3 is disposed around the COB matrix 2, and the second dam 4 is disposed in the gaps between the rows and columns of light-emitting chips 21. The first dam 3 forms a physical barrier, restricting the lateral diffusion of the phosphor, ensuring that light is concentrated on the target area, reducing light scattering loss, and improving light efficiency. The second dam 4 divides the light-emitting area into multiple independent units, preventing the bonding wires 5 from being displaced, broken, or short-circuited due to external impacts, vibrations, or subsequent processes.
[0046] Understandably, the first dam 3 is a larger dam formed by damming adhesive, the height of the first dam 3 is higher than the height of the second dam 4, and the width on the substrate 1 is also wider than the gap between the adjacent light-emitting chips 21.
[0047] Furthermore, the second dam 4 includes a first dam 41 protruding from the substrate 1 and a second dam 42 covering the first dam 41, with the second dam 42 covering a portion of the bonding wire 5. The first dam 41 provides initial fixation for the bonding wire 5, and the second dam 42 can be seen as an elevation of the first dam 41, achieving the effect of covering the bonding wire 5. It also prevents the dispensing needle from contacting the bonding wire 5 during the installation of the second dam 4. There are gaps between the rows and columns of light-emitting chips 21, but these gaps are small. After the bonding wires 5 of the light-emitting chips 21 are soldered, the bonding wires 5 are generally higher than the height of the light-emitting chips 21. Therefore, a finer dispensing needle is needed for the dispensing operation of the second dam 4. However, if the needle tip is too low, it will contact the bonding wire 5, easily causing problems such as desoldering, cold solder joints, and breakage of the bonding wire 5.
[0048] Furthermore, the height of the first layer of dam 41 is no higher than the height of the light-emitting chip 21. The first layer of dam 41 is formed by white wall adhesive. The first layer of dam 41 formed by white wall adhesive can scatter the light emitted by the COB dot matrix 2, eliminate local bright spots, and improve the uniformity of the projected light spot. Moreover, the cured white wall adhesive 4 can form a stable optical interface, constrain the output angle of light, and avoid image defocusing caused by multispectral optical axis shift. The height of the second layer of dam 42 is higher than the height of the light-emitting chip 21, which can prevent light from interfering with each other between adjacent light-emitting chips 21, thereby improving display contrast and color purity. The second layer of dam 42 is formed by damming adhesive. It should be noted that the height of the adhesive layer here refers to the height after curing.
[0049] Alternatively, the first layer of dam 41 may be a dam formed by dam adhesive. The dam adhesive used here may be the same as the dam adhesive used in the first dam 3 and the dam adhesive used in the second layer of dam 42. Specifically, the dam adhesive may be a conventional high-reflectivity colloid in the art.
[0050] In some specific embodiments, the damming adhesive or white wall adhesive is placed in the finest dispensing needle and applied to the gap between adjacent light-emitting chips 21 using the finest needle, forming a first dam 41. Subsequently, after the first dam 41 has cured, the damming adhesive is placed in the finest dispensing needle to further enhance the first dam 41, forming a second dam 42, which covers part of the bonding wire 5. The second dam 42 can be installed after the first dam 3 has cured or before the dispensing operation of the first dam 3.
[0051] Understandably, the area formed by the first dam 3 is also filled with a fluorescent adhesive layer 6 covering the light-emitting chip 21, which adjusts the emission wavelength of the light-emitting chip 21 and homogenizes the emission. At the same time, the fluorescent adhesive layer 6 encapsulates the light-emitting chip 21, protecting it from the influence of moisture, dust, chemicals and other external environmental factors. It also seals and covers the electrodes and bonding wires 5 in the COB dot matrix 2, ensuring the reliability of the electrical connection and thus extending the service life of the dot matrix imaging COB light source.
[0052] Accordingly, this utility model also provides a high-power COB display light-emitting device, including the aforementioned dot-matrix imaging COB light source. The high-power COB display light-emitting device obtained in this application has high brightness, small dot spacing, and uniform light emission, and has the potential to fill the market gap in low-to-mid-range projection products.
[0053] The above-disclosed embodiment is merely a preferred embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.
Claims
1. A dot-matrix imaging COB light source, characterized in that, Includes a substrate and a COB dot matrix packaged on the substrate in a COB manner; The COB dot matrix includes light-emitting chips arranged in rows and columns. The first electrode of all the light-emitting chips in each row is connected to the corresponding row pin, and the second electrode of all the light-emitting chips in each column is connected to the corresponding column pin.
2. The dot matrix imaging COB light source as described in claim 1, characterized in that, The light-emitting chips are electrically connected to the substrate via bonding wires, and the tail end of the bonding wires bonded to the light-emitting chips in each column is connected to the head end of the bonding wires bonded to the adjacent light-emitting chips.
3. The dot matrix imaging COB light source as described in claim 1, characterized in that, The substrate is also provided with a dam, which includes a first dam and a second dam. The first dam is arranged around the COB dot matrix, and the second dam is arranged in the gap between the light-emitting chips arranged in rows and columns.
4. The dot matrix imaging COB light source as described in claim 3, characterized in that, The second dam includes a first dam protruding from the substrate and a second dam covering the first dam, the second dam covering a portion of the bonding wire.
5. The dot matrix imaging COB light source as described in claim 4, characterized in that, The height of the first layer of dam after solidification is not higher than the height of the light-emitting chip; the height of the second layer of dam is higher than the height of the light-emitting chip.
6. The dot matrix imaging COB light source as described in claim 4 or 5, characterized in that, The first layer of the enclosure is a enclosure formed by white wall adhesive, or the first layer of the enclosure is a enclosure formed by enclosure adhesive. The second layer of the dam is a dam formed by dam adhesive.
7. The dot matrix imaging COB light source as described in claim 1, characterized in that, In the COB dot matrix, the light-emitting chips are closely arranged on the substrate, and the distance between two adjacent light-emitting chips in the horizontal direction is less than 1 mm. In the vertical direction, the spacing between two adjacent light-emitting chips is less than 1 mm.
8. The dot matrix imaging COB light source as described in claim 1, characterized in that, The substrate is one or more of copper substrate, aluminum substrate, and ceramic substrate; The COB dot matrix is an 8x8 array; The COB dot matrix can be a monochrome COB dot matrix, a two-color COB dot matrix, or a full-color COB dot matrix.
9. The dot matrix imaging COB light source as described in claim 3, characterized in that, The area formed by the first dam is also filled with a fluorescent adhesive layer covering the light-emitting chip.
10. A high-power COB display light-emitting device, characterized in that, Includes a dot matrix imaging COB light source as described in any one of claims 1-9.