LED flexible module based on COB packaging

Abstract

The utility model relates to the technical field of LED curved display screens, in particular to an LED flexible module based on COB packaging, which comprises an LED display lamp panel and a rubber shell. The LED display lamp panel comprises a PCB (Printed Circuit Board), a plurality of LED driving chips and a plurality of display pixel arrays packaged by COB (Chip On Board); a plurality of display pixel arrays are arranged on the front face of the PCB in an array mode. The plurality of LED driving chips are arranged on the back surface of the PCB; the plurality of display pixel arrays are correspondingly and electrically connected with the plurality of LED driving chips; the common cathode of the display pixel array is connected with the LED driving chip; the rubber shell is detachably connected with the PCB; a plurality of heat dissipation hole groups are formed in the rubber shell; the heat dissipation hole group is arranged right behind the LED driving chip along the direction vertical to the end surface of the PCB; the PCB and the rubber shell are both flexible board bodies. The inverted common-cathode COB display module saves energy by nearly 40% under the same condition, achieves green and low carbon, and is good in heat dissipation performance and high in circuit stability.

Description

Technical Field

[0001] The utility model relates to the technical field of LED curved display screens, and particularly relates to an LED flexible module based on COB packaging. Background Technique

[0002] COB packaging is a high-efficiency integrated surface light source technology in which LED driving chips are directly attached to a highly reflective mirror metal substrate. This technology eliminates the concept of brackets and has no electroplating, reflow soldering, or chip mounting processes. Therefore, the number of processes is reduced by nearly one-third, and the cost is also saved by one-third. COB light sources are the future trend of LED production and application. The display screen with COB packaging directly solders multiple LED bare chips on a PCB circuit board, establishes an electrical connection between the LED bare chips and the PCB circuit board, and then encapsulates the LED bare chips and wires arranged on the surface of the PCB circuit board with resin.

[0003] The LED flexible module is used to assemble a curved display screen. The LED flexible module has a certain elasticity, so it can be bent at a certain angle. By attaching multiple LED flexible modules to the curved surface, a light-emitting curved surface is formed. The LED flexible module encapsulated by COB technology integrates a large number of LED lamp beads, and the heat generated by the PCB circuit board is relatively high. If the heat dissipation is not timely, it will affect the service life of the LED flexible module. Most of the existing LED flexible modules dissipate heat by opening heat dissipation holes, but the distribution of the heat dissipation holes is relatively random, and the heat dissipation performance is poor. Summary of the Utility Model

[0004] (1) Technical Problems to be Solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides an LED flexible module based on COB packaging, which solves the technical problem of poor heat dissipation performance of the LED flexible module.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the LED flexible module based on COB packaging of the utility model includes an LED display lamp board and a plastic shell; the LED display lamp board includes a PCB circuit board, multiple LED driving chips, and multiple display pixel arrays encapsulated by COB;

[0008] Multiple display pixel arrays are arranged in an array on the front surface of the PCB circuit board; multiple LED driving chips are arranged on the back surface of the PCB circuit board; multiple display pixel arrays are electrically connected to multiple LED driving chips correspondingly; the display pixel arrays are connected to the LED driving chips in a common cathode manner;

[0009] The plastic shell is detachably connected to the PCB circuit board; multiple heat dissipation hole groups are formed in the plastic shell; along the direction perpendicular to the end face of the PCB circuit board, the heat dissipation hole groups are formed directly behind the LED driving chips; both the PCB circuit board and the plastic shell are flexible plate bodies.

[0010] Optionally, multiple LED driving chips are uniformly arranged on the PCB circuit board in the horizontal direction.

[0011] Optionally, multiple clearance slots are formed in the plastic shell;

[0012] Multiple LED driving chips are correspondingly arranged in multiple clearance slots;

[0013] The heat dissipation hole group includes multiple heat dissipation holes formed in the clearance slots.

[0014] Optionally, multiple first concave grooves are formed in the plastic shell in the horizontal direction.

[0015] Optionally, the heat dissipation hole group is formed in the first concave grooves.

[0016] Optionally, multiple magnets are arranged along the circumference of the back surface of the PCB circuit board;

[0017] Multiple through holes are formed along the circumference of the plastic shell; the through holes are sleeved on the magnets; the surface of the magnet facing away from the PCB circuit board and the surface of the plastic shell facing away from the PCB circuit board are in the same plane.

[0018] Optionally, the LED flexible module further includes a sleeve;

[0019] The sleeve is arranged on the back surface of the PCB circuit board; the sleeve is sleeved on the magnet; the through hole is sleeved on the sleeve.

[0020] Optionally, the sleeve is a flexible sleeve body; a pair of second concave grooves are formed in the sleeve in the longitudinal direction.

[0021] Optionally, the surfaces of multiple display pixel arrays after COB packaging are filled by potting.

[0022] (III) Beneficial effects

[0023] The beneficial effects of the present utility model are as follows:

[0024] The display pixel array after COB packaging is different from the traditional pixel point light emission, and is approximately surface light source light emission, with more uniform light emission. When watching the screen for a long time in scenarios such as conference rooms and monitoring centers, the eyes will not get tired, which protects the eye health.

[0025] Both the PCB circuit board and the plastic shell are flexible plates. The plastic shell can be bent together with the PCB circuit board, withstand a certain amount of deformation, improving the adaptability of applying the COB technology to the LED flexible module, enhancing the softness of the LED flexible module, and thus increasing the maximum bending angle of the LED flexible module.

[0026] The display pixel array is connected to the LED driver chip in a common cathode manner, and the LED driver chip is flip-chip mounted on the PCB circuit board to form a flip-chip common cathode COB display module. The common cathode setting reduces the total number of cathodes of the LED flexible module, decreasing the volume of the LED flexible module; the heat generation and power consumption of the PCB circuit board are reduced. The flip-chip mounting significantly reduces the number of leads and solder joints, improving the electrical performance and remarkably reducing the thickness of the LED flexible module. The module is only 3.75 mm thick, occupying little space, being ultra-thin, ultra-light, ultra-soft, and having good flatness; the LED driver chip is in direct contact with the PCB circuit board, enhancing the heat dissipation performance. The flip-chip common cathode COB display module saves nearly 40% of energy under the same conditions, achieving green and low-carbon, having good heat dissipation performance, and strong circuit stability.

[0027] The plastic shell is detachably connected to the PCB circuit board, facilitating the connection with the plastic shell after the PCB circuit board is encapsulated, simplifying the assembly process. The heat dissipation hole group is opened directly behind the LED driver chip, that is, corresponding to the position close to the LED driver chip, shortening the heat dissipation channel of the heat of the LED driver chip and achieving targeted and efficient heat dissipation. The plastic shell cooperates with the PCB circuit board to achieve efficient heat dissipation on both the front and back sides of the LED driver chip, improving the adaptability of the LED flexible module under high-temperature conditions. Description of the Drawings

[0028] Figure 1 Is a perspective view of the front of the LED flexible module based on COB packaging of the present invention;

[0029] Figure 2 Is a rear view of the LED flexible module based on COB packaging of the present invention;

[0030] Figure 3 Is a bottom view of the LED flexible module based on COB packaging of the present invention;

[0031] Figure 4 Is a connection schematic diagram of the PCB circuit board and the LED driver chip of the present invention;

[0032] Figure 5 Is a connection schematic diagram of the plastic shell and the LED driver chip of the present invention;

[0033] Figure 6 Is a distribution schematic diagram of the first concave grooves on the plastic shell of the present invention;

[0034] Figure 7 Schematic diagram of the distribution of the clearance groove of the present utility model on the plastic shell;

[0035] Figure 8 Schematic diagram of the connection between the magnet and the sleeve of the present utility model.

[0036]

Description of the reference numerals in the drawings

[0037] 1: LED display lamp board;

[0038] 2: PCB circuit board;

[0039] 3: LED driver chip;

[0040] 4: Magnet;

[0041] 5: Sleeve; 51: Second concave groove;

[0042] 6: Plastic shell; 61: Clearance groove; 62: Heat dissipation hole group; 63: First concave groove; 64: Through hole. Detailed implementation manners

[0043] In order to better explain the present utility model for easy understanding, the present utility model will be described in detail below with reference to the drawings through specific implementation manners.

[0044] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0045] In addition, the descriptions such as "first" and "second" in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0046] In the present utility model, unless otherwise clearly specified and defined, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; "connection" can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0047] See also Figures 1 to 5 The utility model provides an LED flexible module based on COB packaging, the LED flexible module includes an LED display light board 1 and a plastic shell 6; the LED display light board 1 includes a PCB circuit board 2, a plurality of LED driver chips 3 and a plurality of display pixel arrays of COB packaging (not shown); a plurality of display pixel arrays are arranged on the front array of the PCB circuit board 2; a plurality of LED driver chips 3 are arranged on the back of the PCB circuit board 2; a plurality of display pixel arrays are electrically connected to a plurality of LED driver chips 3 correspondingly; the display pixel arrays are connected to the LED driver chips 3 with a common cathode; the plastic shell 6 is detachably connected to the PCB circuit board 2; a plurality of heat dissipation hole groups 62 are provided on the plastic shell 6; along a direction perpendicular to the end surface of the PCB circuit board 2, the heat dissipation hole group 62 is provided directly behind the LED driver chip 3; the PCB circuit board 2 and the plastic shell 6 are both flexible board bodies.

[0048] COB packaging completely seals the device on the PCB circuit board 2, so there is no LED lamp bead link, so there is no adverse phenomenon of lamp falling during transportation, installation and disassembly. Therefore, the first thing that the COB-packaged LED flexible module solves is the protection that traditional technology cannot achieve. It has anti-collision, waterproof, moisture-proof, anti-oxidation, anti-static, anti-vibration, anti-blue light, etc., which is the famous "Ten Protection" technology.

[0049] The display pixel array of COB package is different from the traditional pixel point light emission. It is similar to the surface light source light emission and has more uniform light emission. It will not cause eye fatigue when watching the screen for a long time in scenes such as conference rooms and monitoring centers, and it protects eye health.

[0050] The PCB circuit board 2 and the plastic shell 6 are both flexible boards. The plastic shell 6 can be bent together with the PCB circuit board 2 and withstand certain deformation, which improves the adaptability of applying COB technology to LED flexible modules, improves the softness of LED flexible modules, and thereby improves the maximum bending angle of the LED flexible modules.

[0051] The display pixel array is connected to the LED driving chip 3 with a common cathode, and the LED driving chip 3 is flip-chip mounted on the PCB board 2 to form a flip-chip common cathode COB display module. The common cathode setting reduces the total number of cathodes of the LED flexible module, and the volume of the LED flexible module is reduced; the heat generation and power consumption of the PCB board 2 are reduced. The flip-chip setting significantly reduces the number of leads and solder joints, improves the electrical performance, and significantly reduces the thickness of the LED flexible module. The module thickness is only 3.75 mm thick, occupying less space, being ultra-thin, ultra-light, ultra-soft, and having good flatness; the LED driving chip 3 is in direct contact with the PCB board 2, improving the heat dissipation performance. The flip-chip common cathode COB display module saves nearly 40% of energy under the same conditions, realizes green and low-carbon, has good heat dissipation performance, and strong circuit stability. As for the principles of the common cathode setting and the flip-chip setting of the chip, they are prior arts.

[0052] After the LED driving chip 3 is flip-chip mounted, the active layer is closer to the PCB board 2, shortening the heat flow path from the heat source to the PCB board 2, and having a lower thermal resistance; suitable for high-current driving, with higher luminous efficiency; excellent reliability, which can improve the product life and reduce the product maintenance cost; the size can be made smaller, and the optics is easier to match. The COB packaging process is a relatively mature packaging form for the small-pitch LED series. It can not only make the pitch of the LEDs smaller, with better display effects, but also has better stability, greatly reducing the problem of dead lamp rate; energy-saving and comfortable, with a good near-screen experience, and all flip-chip light-emitting chips. Under the same brightness conditions, the power consumption is reduced by 45%. With a unique heat dissipation technology, under the same brightness, the surface temperature of the screen is 10 °C lower than that of the conventional front-mounted chip LED display screen, which is more suitable for the application scenarios of near-screen experience.

[0053] The core of the COB packaging is to directly integrate the light-emitting chips (display pixel array) on the PCB board 2, rather than the traditional method of first packaging and then mounting. During the COB packaging process, the LED driving chip 3 is directly fixed on the PCB board 2 through conductive adhesive or welding, and then electrical connection and optical packaging are carried out through precise equipment to form complete display screen pixel points in connection with the display pixel array. Compared with the traditional SMD packaging method, the COB packaging does not package into LED lamp beads, and the display screen pixel points have higher integration, stronger heat dissipation performance, and more stable performance. At the same time, the COB packaging process also has the advantages of high production efficiency and low cost, so it has broad application prospects in the field of LED display screens.

[0054] The plastic shell 6 is detachably connected to the PCB circuit board 2, which facilitates the connection between the PCB circuit board 2 and the plastic shell 6 after the PCB circuit board 2 is encapsulated, simplifying the assembly process. The heat dissipation hole group 62 is opened directly behind the LED driving chip 3, that is, it is correspondingly arranged at a position close to the LED driving chip 3, shortening the heat dissipation channel of the heat of the LED driving chip 3 and achieving targeted and efficient heat dissipation. The plastic shell 6 and the PCB circuit board 2 cooperate to achieve efficient heat dissipation on both the front and back sides of the LED driving chip 3, enabling the LED flexible module to not delaminate and have no warpage at high and low temperatures (-40° to 100°), and being able to play protective roles such as anti-static and anti-collision, effectively protecting the components inside the plastic shell 6 and improving the reliability of the LED flexible module.

[0055] Further, multiple LED driving chips 3 are evenly arranged on the PCB circuit board 2 in the horizontal direction. Taking Figure 5 the shown orientation as an example, the horizontal direction is the length direction of the plastic shell 6; the vertical direction is the width direction of the plastic shell 6; the direction perpendicular to the end face of the PCB circuit board 2 is the bending direction, that is, the LED flexible module can be bent into an arc shape along this direction to adapt to the installation of a curved display screen. Based on this, multiple LED driving chips 3 are evenly arranged on the PCB circuit board 2 in the horizontal direction, leaving a deformation space between adjacent LED driving chips 3 in the horizontal direction to adapt to the bending deformation of the LED flexible module, increasing the maximum bending angle of the LED flexible module, and avoiding compression and collision between adjacent display pixel arrays. As for the number and arrangement gap of the LED driving chips 3 in the vertical direction, they can be set according to actual needs.

[0056] As Figure 6 shown in Figure 7 and

[0057] shown, a plurality of clearance grooves 61 are opened on the plastic shell 6; a plurality of LED driving chips 3 are correspondingly arranged in the plurality of clearance grooves 61; the heat dissipation hole group 62 includes a plurality of heat dissipation holes opened in the clearance grooves 61. On the one hand, the clearance grooves 61 can improve the limiting strength of the plurality of LED driving chips 3 and enhance the overall stability of the LED flexible module. On the other hand, the setting of the clearance grooves 61 reduces the thickness of the plastic shell 6, that is, reduces the heat dissipation path of the LED driving chips 3 in the clearance grooves 61, achieving efficient heat dissipation. In addition, the heat dissipation hole group 62 is directly opened in the clearance grooves 61, further enhancing the heat dissipation performance of the plastic shell 6. In this embodiment, clearance grooves 61 are provided at the places on the PCB circuit board 2 where the driving IC, connectors, and capacitors are cooperated, for targeted and efficient heat dissipation of the heat-generating components.By targeting the arrangement of multiple heat dissipation holes close to the LED driving chip 3, the heat dissipation channels of the LED driving chip 3 are expanded, and the heat dissipation performance of the plastic housing 6 is improved. Optionally, the multiple heat dissipation holes are arranged longitudinally to reduce the resistance suffered when the LED flexible module is bent, making the LED flexible module easier to bend and improving the convenience of disassembly and assembly of the LED flexible module. In this embodiment, the aperture of the heat dissipation hole is not greater than 3 mm. The small hole process is used to protect the internal components over a large area and play a heat dissipation function. With super five-star protection, the screen body can easily cope with various environmental tests.

[0058] In addition, a plurality of first concave grooves 63 are transversely formed on the upper edge of the plastic housing 6. Similarly, the first concave grooves 63 can reduce the resistance suffered when the LED flexible module is bent, making the LED flexible module easier to bend and improving the convenience of disassembly and assembly of the LED flexible module. At the same time, the concave groove structure increases the heat dissipation surface of the plastic housing 6, further improving the heat dissipation performance of the plastic housing 6; the concave groove structure also provides sufficient deformation space inside the concave groove, increasing the maximum angle at which the LED flexible module can be bent and improving the installation adaptability to display screens with different curvature degrees.

[0059] Furthermore, the heat dissipation hole group 62 is formed on the first concave groove 63. Specifically, the heat dissipation hole group 62 can be formed on the inner wall bottom surface of the first concave groove 63. The inner wall bottom surface of the first concave groove 63 is relatively thin, which is more conducive to heat dissipation after the heat dissipation hole group 62 is formed, and the resistance suffered when the LED flexible module is bent is also smaller. By connecting the heat dissipation holes to the clearance groove 61 and the first concave groove 63, the heat dissipation path of the LED driving chip 3 is further reduced, achieving efficient heat dissipation.

[0060] Secondly, a plurality of magnets 4 are arranged along the circumferential direction of the back surface of the PCB circuit board 2; a plurality of through holes 64 are formed along the circumferential direction of the plastic housing 6; the through holes 64 are sleeved on the magnets 4; the surface of the magnet 4 facing away from the PCB circuit board 2 is in the same plane as the surface of the plastic housing 6 facing away from the PCB circuit board 2. The quick disassembly and assembly of the PCB circuit board 2 and the plastic housing 6 can be realized by the sleeving method, enabling the PCB circuit board 2 to be assembled with the plastic housing 6 after potting, which simplifies the production process. By setting the surface of the magnet 4 facing away from the PCB circuit board 2 and the surface of the plastic housing 6 facing away from the PCB circuit board 2 in the same plane, the magnet 4 can be effectively protected by the plastic housing 6, and the adsorption strength of the magnet 4 can be effectively ensured. Through the magnet 4, the LED flexible module can be firmly adsorbed on the panel of the curved display screen, and the installation is very convenient, facilitating the adjustment of the installation position of the LED flexible module on the panel of the curved display screen at any time, so that multiple LED flexible modules can be assembled into a curved display screen with high fitting accuracy.

[0061] Such as Figure 8As shown, the LED flexible module further includes a sleeve 5; the sleeve 5 is arranged on the back of the PCB circuit board 2; the sleeve 5 is sleeved on the magnet 4; the through hole 64 is sleeved on the sleeve 5. Since the magnet 4 needs to be glued directly onto the PCB circuit board 2, the process is rather cumbersome. By fixedly connecting the sleeve 5 to the PCB circuit board and then snap-fitting the magnet 4 into the sleeve 5, there is no need for additional application of glue, thus simplifying the installation process.

[0062] Furthermore, the sleeve 5 is a flexible sleeve body; a pair of second concave grooves 51 are longitudinally formed in the sleeve 5. Similarly, the flexible sleeve body enables the sleeve 5 to withstand a certain amount of deformation and adapt to the curved surface deformation installation of the LED flexible module; at the same time, it can elastically snap-fit the magnet 4 into the sleeve 5. The second concave grooves 51 can reduce the resistance suffered when the LED flexible module is bent, making the LED flexible module easier to bend and improving the convenience of disassembly and assembly of the LED flexible module. Moreover, the second concave grooves 51 also facilitate the removal of the magnet 4 in the sleeve 5, which is convenient for maintenance and replacement.

[0063] Secondly, the surfaces of multiple display pixel arrays after COB packaging are further potted and filled. That is, glue is applied again on the basis of COB packaging to further enhance the protection of the multiple display pixel arrays. The protection level reaches IP65, and it can play a role in anti-static, anti-collision and other protections, improving the reliability of the product.

[0064] It should be understood that the above description of the specific embodiments of the present invention is only for explaining the technical route and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, the present invention is not limited to the above specific implementation manners. Any changes or modifications made within the scope of the claims of the present invention should be covered by the protection scope of the present invention.

Claims

1. A LED flexible module based on COB packaging, characterized in that: The LED flexible module comprises an LED display light board (1) and a plastic shell (6); the LED display light board (1) comprises a PCB circuit board (2), a plurality of LED driving chips (3) and a plurality of display pixel arrays packaged in a COB package; A plurality of display pixel arrays are arranged on the front array of the PCB circuit board (2); The plurality of LED driver chips (3) are arranged on the back side of the PCB circuit board (2); the plurality of display pixel arrays are electrically connected to the plurality of LED driver chips (3) correspondingly; the display pixel arrays are connected to the LED driver chips (3) via a common cathode; The plastic shell (6) is detachably connected to the PCB circuit board (2); a plurality of heat dissipation hole groups (62) are provided on the plastic shell (6); along a direction perpendicular to the end surface of the PCB circuit board (2), the heat dissipation hole group (62) is provided directly behind the LED driver chip (3); the PCB circuit board (2) and the plastic shell (6) are both flexible boards.

2. The LED flexible module based on COB packaging according to claim 1, characterized in that: The plurality of LED driving chips (3) are evenly arranged on the PCB circuit board (2) in the transverse direction.

3. The LED flexible module based on COB packaging according to claim 2, characterized in that: The plastic shell (6) is provided with a plurality of air-avoiding grooves (61); The plurality of LED driving chips (3) are correspondingly arranged in the plurality of air-avoiding grooves (61); The heat dissipation hole group (62) comprises a plurality of heat dissipation holes opened in the air avoidance groove (61).

4. The LED flexible module based on COB packaging according to any one of claims 1 to 3, characterized in that: The upper edge of the plastic shell (6) is provided with a plurality of first concave grooves (63) in a transverse direction.

5. The LED flexible module based on COB packaging according to claim 4, characterized in that: The heat dissipation hole group (62) is formed on the first concave groove (63).

6. The LED flexible module based on COB packaging according to any one of claims 1 to 3, characterized in that: A plurality of magnets (4) are arranged on the back side of the PCB circuit board (2) along its circumference; The plastic shell (6) is provided with a plurality of through holes (64) along its circumference; the through holes (64) are sleeved on the magnet (4); a side of the magnet (4) facing away from the PCB circuit board (2) and a side of the plastic shell (6) facing away from the PCB circuit board (2) are located in the same plane.

7. The LED flexible module based on COB packaging according to claim 6, characterized in that: The LED flexible module also includes a sleeve (5); The sleeve (5) is arranged on the back side of the PCB circuit board (2); the sleeve (5) is sleeved on the magnet (4); and the through hole (64) is sleeved on the sleeve (5).

8. The LED flexible module based on COB packaging according to claim 7, characterized in that: The sleeve (5) is a flexible sleeve; the sleeve (5) is provided with a pair of second concave grooves (51) along the longitudinal direction.

9. The LED flexible module based on COB packaging according to any one of claims 1 to 3, characterized in that: Surface encapsulation and filling of multiple display pixel arrays after COB packaging.

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