LED display screen and preparation method thereof

Abstract

The invention discloses an LED display screen and a preparation method thereof, and relates to the technical field of display. The LED display screen comprises an LED display panel, a box body and a heat pipe heat dissipation structure, the LED display panel comprises a composite heat dissipation substrate and a plurality of LEDs arranged in an array mode, the box body is fixed to the side, away from the LEDs, of the composite heat dissipation substrate, the heat pipe heat dissipation structure is located in a containing space, the heat pipe heat dissipation structure comprises a heat pipe and a working medium, and the working medium is located in the heat pipe heat dissipation structure. One end of the heat pipe is communicated with the heat conduction hole, the other end of the heat pipe is connected with the box body, the heat pipe is filled with the working medium, and the working medium is used for moving in the heat pipe to dissipate heat of the LED display panel when monitoring that the temperature in the containing space is beyond a threshold value range and moving in the heat pipe to dissipate heat of the LED display panel when monitoring that the temperature in the containing space is within the threshold value range. The working medium is static in the heat pipe. According to the LED display panel, good heat dissipation can be conducted jointly through the composite heat dissipation substrate and the heat pipe heat dissipation structure, and therefore the performance of an LED display screen is good.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and specifically relates to an LED display screen and a method for manufacturing the same. Background Art

[0002] With the continuous development of outdoor light emitting diode (LED) display technology, chip on board (COB) display screens have been widely studied and applied in outdoor advertising, information display and other fields due to their advantages such as high reliability and high protection.

[0003] However, during the operation of the COB display, the LED chip will generate a lot of heat. If the heat on the LED chip cannot be dissipated in a timely and effective manner, the excessively high temperature will cause the LED chip's luminous efficiency to decrease, the color to drift, and even accelerate the aging of the LED chip, which not only affects the performance of the COB display, but also shortens its service life.

[0004] Traditional heat dissipation methods for COB displays mostly rely on simple heat sinks or fans. However, in outdoor environments, heat sinks are easily affected by dust and rain, resulting in a gradual decrease in heat dissipation efficiency. Fans, on the other hand, have low protection levels and are prone to water and dust ingress, leading to high failure rates. Furthermore, the noise generated by fan operation makes them unsuitable for use in noise-sensitive environments. Summary of the Invention

[0005] The purpose of this application is to overcome the above-mentioned shortcomings of the prior art and provide an LED display screen and a preparation method thereof to solve the problems of low heat dissipation efficiency and poor reliability existing in the existing heat dissipation methods of outdoor LED display screens, thereby ensuring that the LED display screen can work stably and efficiently in outdoor environments and extend its service life.

[0006] In order to achieve the above application objectives, the first aspect of the present application provides an LED display screen, comprising:

[0007] An LED display panel includes a composite heat dissipation substrate and a plurality of LEDs arranged in an array, wherein the composite heat dissipation substrate includes a metal layer and a non-metal layer, the metal layer is disposed on one side of the non-metal layer, the LEDs are soldered to a side of the metal layer away from the non-metal layer, and the composite heat dissipation substrate has at least one heat conduction hole penetrating the metal layer and the non-metal layer;

[0008] A box body is fixed on a side of the composite heat dissipation substrate away from the LED, and a receiving space is enclosed between the box body and the composite heat dissipation substrate;

[0009] A heat pipe heat dissipation structure is located in the accommodating space. The heat pipe heat dissipation structure includes a heat pipe and a working fluid. One end of the heat pipe is communicated with the heat conduction hole, and the other end of the heat pipe is connected to the box. The working fluid is filled in the heat pipe. When the temperature in the accommodating space is monitored to be outside a threshold range, the working fluid moves in the heat pipe to dissipate heat for the LED display panel. When the temperature in the accommodating space is monitored to be within the threshold range, the working fluid remains stationary in the heat pipe.

[0010] In some embodiments, the metal layer is a copper layer, and the non-metal layer is a ceramic layer.

[0011] In some embodiments, the box includes a bottom surface, a first side surface, and a second side surface, one end of the first side surface is connected to one end of the second side surface through the bottom surface, and the other end of the first side surface and the other end of the second side surface are both connected to the LED display panel;

[0012] The bottom surface is a heat dissipation fin array, which includes a plurality of sub-heat dissipation fins. Two adjacent sub-heat dissipation fins are connected end to end, and the shape of each sub-heat dissipation fin is non-linear.

[0013] In some embodiments, at least some of the sub-heat sink fins in the heat sink fin array are concave toward the LED display panel, and / or at least some of the sub-heat sink fins in the heat sink fin array are convex toward the LED display panel.

[0014] In some embodiments, the LED display screen further includes a nano-heat dissipation coating, and the nano-heat dissipation coating is disposed on a side of the bottom surface of the box away from the LED display panel.

[0015] In some embodiments, the LED display further includes a sensor and an intelligent heat dissipation control module.

[0016] The sensor is arranged in the accommodation space, one end of the sensor is connected to the bottom surface of the box, and the other end of the sensor is suspended in the accommodation space, and the sensor is used to monitor the temperature in the accommodation space and transmit a signal to the intelligent heat dissipation control module;

[0017] The intelligent heat dissipation control module is arranged in the accommodating space, and the intelligent heat dissipation control module is electrically connected to the sensor, the heat pipe heat dissipation structure and the LED display panel respectively. The intelligent heat dissipation control module is used to receive the signal transmitted by the sensor and make a judgment. When it is judged that the temperature in the accommodating space is outside the threshold range, the working medium is controlled to move in the heat pipe to dissipate heat for the LED display panel, and / or the brightness of the LED display panel is controlled to be reduced, and / or the power consumption of at least one of the LEDs is controlled to be reduced, and when it is judged that the temperature in the accommodating space is within the threshold range, the working medium is controlled to be stationary in the heat pipe, and / or the LED display panel is controlled to maintain constant brightness, and / or the LED is controlled to maintain constant power consumption.

[0018] In some embodiments, the material of the copper layer includes electrolytic copper, and the density of the electrolytic copper is 8.95 g / cc to 8.99 g / cc;

[0019] And / or, the copper layer has a thickness of 0.5 mm to 1.0 mm.

[0020] In some embodiments, the strength of the ceramic layer is greater than or equal to 500 MPa;

[0021] And / or, the Rockwell hardness of the ceramic layer is HRA80-HRA100;

[0022] And / or, the thickness of the ceramic is 0.8 mm-1.5 mm.

[0023] A second aspect of the present application provides a method for preparing an LED display screen, comprising the following steps:

[0024] A composite heat dissipation substrate comprising a metal layer and a non-metal layer is provided, and a plurality of LEDs arranged in an array are soldered to a side of the metal layer away from the non-metal layer to obtain an LED display panel; wherein the composite heat dissipation substrate has at least one heat conduction hole penetrating the metal layer and the non-metal layer;

[0025] A box is fixed on the side of the composite heat dissipation substrate facing away from the LED; wherein a receiving space is enclosed between the box and the composite heat dissipation substrate;

[0026] A heat pipe heat dissipation structure is formed in the accommodating space to obtain the LED display screen; wherein, the heat pipe heat dissipation structure includes a heat pipe and a working medium, one end of the heat pipe is communicated with the heat conduction hole, and the other end of the heat pipe is connected to the box, and the working medium is filled in the heat pipe. When the temperature in the accommodating space is monitored to be outside a threshold range, the working medium moves in the heat pipe to dissipate heat for the LED display panel, and when the temperature in the accommodating space is monitored to be within the threshold range, the working medium remains stationary in the heat pipe.

[0027] In some embodiments, providing a composite heat dissipation substrate including a metal layer and a non-metal layer includes:

[0028] Provide metal materials and non-metal materials;

[0029] The metal material and the non-metal material are sintered at a temperature of 800° C. to 1200° C. to form the composite heat dissipation substrate.

[0030] Compared with the existing technology, this application has the following technical effects:

[0031] The LED display provided by the embodiment of the present application generates heat during operation. Since the LED is directly welded to one side surface of the metal layer, the heat can be directly transferred to the metal layer in direct contact with the LED, and the good thermal conductivity of the metal layer is used to quickly absorb the heat generated by the LED, thereby achieving rapid heat dissipation of the LED, thereby reducing the risk of LED overheating. At the same time, the non-metallic layer is located on the side of the metal layer away from the LED. The non-metallic layer has certain thermal conductivity, high thermal stability and good insulation, so that the composite thermal conductive substrate can achieve effective heat conduction while also ensuring the electrical safety of the LED display, thereby improving the performance and reliability of the LED display. In addition, the heat generated by the LED and the heat generated by the composite heat dissipation substrate itself can also be transferred to the heat pipe heat dissipation structure through the heat conduction holes, so that the LED display panel can be well dissipated through the movement of the working fluid, and the heat dissipation of the LED display panel can be minimized by dust, rain, etc., thereby improving the reliability and stability of the LED display in complex outdoor environments and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 This is a structural diagram of an LED display screen provided in an embodiment of the present application;

[0034] Figure 2 is a top view of an LED display panel provided in an embodiment of the present application;

[0035] Figure 3 This is a structural diagram of another LED display screen provided in an embodiment of the present application;

[0036] Figure 4 This is a structural diagram of another LED display screen provided in an embodiment of the present application;

[0037] Figure 5 This is a process flow chart for preparing an LED display panel provided in an embodiment of the present application;

[0038] Figure 6 This is a process flow chart for preparing a composite heat dissipation substrate provided in an embodiment of the present application;

[0039] Figure 7 This is a process flow chart for preparing an LED display screen provided in an embodiment of the present application;

[0040] Figure 8 This is a flow chart of another process for preparing an LED display screen provided in an embodiment of the present application;

[0041] Figure 9 This is a flow chart of a manufacturing process for another LED display screen provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0043] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0044] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c" or "at least one of a, b and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc or abc, where a, b, c can be single or multiple.

[0045] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0046] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0047] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass in the examples of this application may be a well-known mass unit such as μg, mg, g, kg, etc.

[0048] The terms "first," "second," etc., are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be understood to indicate or imply relative importance or to implicitly specify the number of technical features being referred to. For example, without departing from the scope of the embodiments of this application, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX. Thus, features defined as "first," "second," etc., may explicitly or implicitly include one or more of such features.

[0049] In the first aspect, the embodiment of the present application provides an LED display screen, referring to Figures 1 to 4As shown, the LED display screen may include: an LED display panel, a housing 7, and a heat pipe heat dissipation structure. The LED display panel includes a composite heat dissipation substrate and a plurality of LED chips arranged in an array. The composite heat dissipation substrate includes a metal layer 3 and a non-metallic layer 2. The metal layer 3 is disposed on one side of the non-metallic layer 2, and the LED chips are soldered to the side of the metal layer 3 away from the non-metallic layer 2. The composite heat dissipation substrate has at least one heat conduction hole 14 that penetrates the metal layer 3 and the non-metallic layer 2. The box body 7 is fixed on the side of the composite heat dissipation substrate away from the LED chip. A accommodating space k is enclosed between the box body 7 and the composite heat dissipation substrate. The heat pipe heat dissipation structure is located in the accommodating space k. The heat pipe heat dissipation structure includes a heat pipe 15 and a working medium 16. One end of the heat pipe 15 is connected to the heat conduction hole 14, and the other end of the heat pipe 15 is connected to the box body 7. The working medium 16 is filled in the heat pipe 15. When the temperature in the accommodating space k is monitored to be not within the threshold range (18°C-22°C), the working medium 16 moves in the heat pipe 15 to dissipate heat for the LED chip. When the temperature in the accommodating space k is monitored to be within the threshold range (18°C-22°C), the working medium 16 stays still in the heat pipe 15.

[0050] In practical applications, the LED display panel of the embodiment of the present application may be a COB display panel, etc. In the case where the LED display panel is a COB display panel, the LED display screen is a COB display screen. Figure 1 、 Figures 3 and 4 As shown, the COB display panel of the embodiment of the present application can solder the unpackaged LED chip to the surface of the metal layer 3 in the composite heat dissipation substrate away from the non-metallic layer 2 through solder 5 (for example, solder, etc.), and connect the LED chip to the circuit of the metal layer 3 to achieve electrical connection between the LED chip and the composite heat dissipation substrate. Since the composite heat dissipation substrate is energized, specifically the metal layer 3 is energized, and the non-metallic layer 2 is not energized, the composite heat dissipation substrate is used to control the LED chip to achieve functions such as light emission. Since the COB display panel eliminates the packaging link of the LED chip, it can integrate more LED chips on the same area, improve the pixel density of the COB display panel, and make the display image clearer and more delicate; at the same time, since the thickness of the packaging structure is reduced, the thickness of the entire COB display panel is reduced, which can well achieve lightweight and thinness; in addition, the LED chip is directly connected to the composite heat dissipation substrate, the heat dissipation path is shorter, the heat dissipation effect is better, which is conducive to improving the stability and reliability of the COB display panel and can extend its service life. As a result, COB display screens are increasingly widely used in large display scenes such as outdoor advertising screens, stadium displays, and stage background displays.

[0051] On this basis, after the LED chip in the COB display panel of the embodiment of the present application is directly connected to the metal layer 3, a pore 6 (usually refers to the gap between the LED chip and the metal layer 3 or a tiny cavity at the connection interface) may appear at a position where no solder 5 is provided between the LED chip and the metal layer 3. Since the pore 6 may expose the internal structure (for example, pins, solder joints, etc.), the pore 6 is filled with a packaging material, which can isolate external moisture, dust, corrosive substances, etc., reduce the risk of short circuit between pins or metal oxidation, and at the same time, fix the pins, reduce the risk of pin displacement or solder cracking due to vibration, thermal expansion and contraction, and buffer the stress caused by the difference in thermal expansion coefficient between the LED chip and the metal layer 3, reduce interface fatigue failure (for example, solder joint detachment) and other problems, and improve the long-term reliability of the COB display.

[0052] It should be noted that the LED chip can be connected to the circuit of the metal layer 3 by wire bonding or other connection methods, which depends on the actual application.

[0053] In addition, the above-mentioned packaging materials may include epoxy resin, thermal conductive silicone, optical grade silicone, etc., which are not specifically limited here.

[0054] It should be understood that the colors of light emitted by the multiple LED chips arranged in an array in the embodiment of the present application can be partially the same, completely the same, or completely different, depending on the actual application. Figure 1 、 Figures 3 and 4 The illustrations are all based on an example in which three LED chips capable of emitting light of different colors are integrated on the surface of the metal layer 3 facing away from the non-metal layer 2 , namely a red LED chip 11 , a green LED chip 12 and a blue LED chip 13 . Figure 2 The illustration is based on an example in which the number of LED chips is 36, including 12 red LED chips 11, 12 green LED chips 12 and 12 blue LED chips 13, and each red LED chip 11, green LED chip 12 and blue LED chip 13 constitutes an LED light-emitting unit.

[0055] In practical applications, the composite heat dissipation substrate having at least one heat conduction hole 14 extending through the metal layer 3 and the non-metallic layer 2 means that the composite heat dissipation substrate may have only one heat conduction hole 14 extending through the metal layer 3 and the non-metallic layer 2, or the composite heat dissipation substrate may have multiple heat conduction holes 14 extending through the metal layer 3 and the non-metallic layer 2, without specific limitation herein. To achieve better heat dissipation, the composite heat dissipation substrate may have multiple heat conduction holes 14 extending through the metal layer 3 and the non-metallic layer 2.

[0056] Please refer to Figure 1 、 Figures 3 and 4The LED display screen may further include a packaging structure 4, which may protect the LED chip and the metal layer 3. The material of the packaging structure 4 is not specifically limited here. For example, the material of the packaging structure 4 may be epoxy resin, thermally conductive silicone, optical-grade silicone, or the like. Therefore, each heat conduction hole 14 in the embodiment of the present application may only penetrate the entire metal layer 3 and the entire non-metallic layer 2. Alternatively, in addition to penetrating the entire metal layer 3 and the entire non-metallic layer 2, each heat conduction hole 14 may also penetrate a portion of the packaging structure 4, specifically, penetrate a portion of the packaging structure 4 close to the metal layer 3. There is no specific limit on how much each heat conduction hole 14 penetrates the packaging structure 4, as long as it does not penetrate the entire packaging structure 4.

[0057] In practical applications, the box 7 is fixed on the side of the composite heat dissipation substrate away from the LED chip, which can be as follows: Figure 1 As shown, the box body 7 is directly mounted on the non-metallic layer 2. Specifically, the box body 7 can be directly mounted on the four sides of the non-metallic layer 2, or the box body 7 can be directly mounted on the surface of the non-metallic layer 2 facing away from the metal layer 3. Of course, the box body can also be provided with a mounting groove, and the LED display panel is then fixed in the mounting groove by bolts or other structures. There is no specific limitation here, as long as the LED display panel and the box body are well connected.

[0058] It should be understood that the other end of the heat pipe 15 is connected to the box 7, which can be as follows Figure 1 、 Figures 3 and 4 As shown, the other end of the heat pipe 15 is connected to the bottom surface of the box body 7, or the other end of the heat pipe 15 can be connected to the first side surface or the second side surface of the box body 7, which depends on the actual application.

[0059] The working medium 16 in the embodiment of the present application may include gas, liquid, phase change material, etc., for example, water, refrigerant, liquid organic working medium, etc.

[0060] The working medium 16 is in a sealed environment, and the working medium 16 can be driven to work by temperature changes. The threshold range in the embodiment of the present application can be 18°C-22°C. Thus, when the temperature of the accommodating space k is lower than 18°C ​​or higher than 22°C, the working medium 16 in the heat pipe 15 will move (for example, flow). However, at temperatures below 18°C ​​and above 22°C, the movement of the working medium 16 is different in that: when the temperature in the accommodating space k of the box body 7 is lower than 18°C, the working medium 16 can move from the bottom surface of the box body 7 toward the heat conduction hole 14 in the heat pipe 15, and when the temperature in the accommodating space k of the box body 7 is higher than 22°C, the working medium 16 can move from the heat conduction hole 14 toward the bottom surface of the box body 7 in the heat pipe 15, thereby realizing rapid heat transfer to achieve cooling.

[0061] Since water has a large specific heat capacity and a large latent heat of vaporization, it can effectively absorb and release heat. A relatively stable temperature can be maintained in the heat pipe 15 through the circulation of liquid and gaseous states. Moreover, the temperature of the heat pipe 15 using water as the working medium 16 can be easily controlled at around 20°C. Therefore, water is further selected as the working medium 16.

[0062] It should be noted that the diameter, length, etc. of the heat pipe 15 in the embodiment of the present application can be determined according to the size of the LED display screen to ensure that the heat can be evenly distributed to the edge of the LED display panel and transferred to the outer box 7.

[0063] Figure 2 This is a top view of 12 LED light-emitting units. Figure 2 As shown, a red LED chip 11, a green LED chip 12, and a blue LED chip 13 constitute a light-emitting unit. The green LED chip 12 is located between the red LED chip 11 and the blue LED chip 13. Any two adjacent LED chips are separated and spaced apart. The LED chips and their arrangement in all light-emitting units are the same. Three light-emitting units are arranged in the same row, and four light-emitting units are arranged in the same column. In the first and second rows, the LED chips of the same color in the light-emitting units in the same column can be connected by a circuit (for example, a copper trace 19). In the third and fourth rows, the LED chips of the same color in the light-emitting units in the same column can be connected by a circuit (for example, a copper trace 19). At the same time, all LED chips are soldered to the metal layer 3. Then, a heat conduction hole 14 is opened on the metal layer 3 and passes through it. The heat generated by the LED chips and the metal layer 3 after power is applied can be conducted to the heat pipe heat dissipation structure through the heat conduction hole 14.

[0064] It is worth noting that when there are multiple heat conduction holes 14 on the composite heat dissipation substrate, one end of each heat pipe 15 can be attached to a heat conduction hole 14, and the other end of each heat pipe 15 can be extended to the box body 7. At the same time, the other ends of all heat pipes 15 are connected to the same place of the box body 7, for example, all are connected to Figure 1 、 Figures 3 and 4 The intelligent heat dissipation control module 17 is provided to control the heat pipe heat dissipation structure, which is simple and easy to implement. Of course, the other ends of all the heat pipes 15 may not be connected to the same place of the box body 7, which depends on the actual application.

[0065] The present invention provides an LED display screen that uses an LED chip as a light source. During operation, the LED chip generates heat. Since the LED chip is directly soldered to one surface of the metal layer, the heat can be directly transferred to the metal layer in contact with the LED chip. The metal layer's excellent thermal conductivity quickly absorbs the heat generated by the LED chip, achieving rapid heat dissipation of the LED chip, thereby reducing the risk of overheating of the LED chip. At the same time, a non-metallic layer is located on the side of the metal layer facing away from the LED chip. The non-metallic layer has high thermal stability and good insulation properties. This allows the composite thermally conductive substrate to achieve effective heat conduction while also ensuring the electrical safety of the LED display screen, thereby improving the performance and reliability of the LED display screen. In addition, the heat generated by the LED chip and the heat generated by the composite heat dissipation substrate itself can be transferred to the heat pipe heat dissipation structure through the heat conduction holes. The heat pipe of the heat pipe heat dissipation structure contains a working fluid that can change with temperature. Therefore, the movement of the working fluid can effectively dissipate heat from the LED display panel, and the heat dissipation of the LED display panel can be minimized by dust, rain, etc., thereby improving the reliability and stability of the LED display screen in complex outdoor environments and extending its service life.

[0066] In some embodiments, the metal layer 3 in the embodiment of the present application may be a copper (Cu) layer, etc., and the non-metallic layer 2 may be a ceramic layer, etc.

[0067] In practical applications, when the metal layer 3 is a copper layer, the material of the copper layer may be electrolytic copper, wherein the electrolytic copper may be electrolytic copper with a purity of 99.99%.

[0068] The electrical conductivity of the copper layer can be 5.70×10 7 S / m-5.80×10 7 S / m, for example, the electrical conductivity of the copper layer can be 5.70×10 7 S / m, 5.72×10 7 S / m, 5.74×10 7 S / m, 5.76×10 7 S / m, 5.78×10 7 S / m or 5.80×10 7 S / m, etc. Further, the conductivity of the copper layer can be selected to be 5.80×10 7 S / m. This conductivity indicates that electrons can move relatively freely in the copper layer, allowing current to flow smoothly through the copper layer. This copper layer has excellent electrical conductivity and can also reduce energy loss during power transmission, improving the efficiency and performance of the circuit in the copper layer.

[0069] The thermal conductivity of the copper layer can be 400 W / (M·K)-410 W / (M·K). For example, the thermal conductivity of the copper layer can be 400 W / (M·K), 401 W / (M·K), 404 W / (M·K), 406 W / (M·K), 408 W / (M·K), or 410 W / (M·K). Furthermore, the thermal conductivity of the copper layer can be selected to be 401 W / (M·K). Such a thermal conductivity indicates that the copper layer can effectively conduct heat.

[0070] In practical applications, the resistivity of the ceramic layer can be 10 12 Ω·cm-10 16 Ω·cm, for example, the resistivity of the ceramic layer may be 10 12 Ω·cm, 10 13 Ω·cm, 10 14 Ω·cm, 10 15 Ω·cm or 10 16 Ω·cm, etc. Such resistivity indicates that there are very few free electrons inside the ceramic layer, making it difficult for current to pass through. The ceramic layer has high thermal stability and good insulation, which can reduce the risk of current leakage and short circuit. In addition, it can also protect the copper layer, thereby ensuring that the composite heat dissipation substrate works well.

[0071] In some embodiments, reference Figures 3 and 4 As shown, the box body 7 includes a bottom surface, a first side surface and a second side surface, one end of the first side surface is connected to one end of the second side surface through the bottom surface, and the other end of the first side surface and the other end of the second side surface are both connected to the LED display panel; the bottom surface is a heat dissipation fin array 9, and the heat dissipation fin array 9 includes a plurality of sub-heat dissipation fins, and two adjacent sub-heat dissipation fins are connected end to end, and the shape of each sub-heat dissipation fin is non-linear.

[0072] In actual applications, the shapes of the above-mentioned multiple sub-heating fins can be exactly the same or completely different. In order to facilitate production and installation, the shapes of the multiple sub-heating fins can be the same. The specific shape of each sub-heating fin is not limited here. For example, each sub-heating fin is concave toward the LED display panel, so that the heat dissipation fin array 9 is wavy. Alternatively, each sub-heating fin is convex toward the LED display panel, so that the heat dissipation fin array 9 is wavy. Alternatively, some sub-heating fins are concave toward the LED display panel, and the remaining sub-heating fins are convex toward the LED display panel, and the concave and convex sub-heating fins can be connected, so that the heat dissipation fin array 9 is wavy.

[0073] The material of the sub-heat sink fins may include aluminum alloy, etc. Specifically, the aluminum alloy may be rust-proof aluminum alloy 5A02, 5A03, etc. Thus, the heat sink fins may have the properties of light weight, good heat dissipation, etc.

[0074] An embodiment of the present application provides an LED display screen, which forms a non-linear shape by setting the shape of the sub-heat sink fins to a non-linear shape, so that the shape of the entire heat sink fin array is non-linear (for example, a wavy shape), thereby increasing the contact area between the heat sink fin array and the air. In this way, the composite heat sink substrate, the sealed heat pipe and the heat sink fin array with good protection performance are used in combination to form an efficient heat dissipation channel, which can quickly absorb, transfer and dissipate the heat generated by the LED chip, reduce the heat accumulation of the LED chip, effectively reduce the temperature of the LED display panel, further improve the heat dissipation efficiency, and at the same time protect the light decay of the LED chip, thereby extending the service life of the LED chip. In addition, it can also reduce the impact of dust, rainwater, etc. on heat dissipation, which comprehensively enhances the reliability and stability of the LED display screen in complex outdoor environments.

[0075] In some embodiments, reference Figure 4 As shown, the LED display screen further includes a nano heat dissipation coating 18 , which can be provided on a side of the bottom surface of the box body 7 away from the LED display panel.

[0076] Furthermore, the nano heat dissipation coating 18 can be provided on a side of the heat dissipation fin array 9 away from the LED display panel.

[0077] In practical applications, objects can approach a black body in the infrared band (especially 5μm-20μm). Meanwhile, the infrared band of 8μm-13μm is the "transparent window" of the Earth's atmosphere (referred to as the atmospheric window). To efficiently convert heat into radiant energy and dissipate it through the nano-heat dissipation coating 18, the material of the nano-heat dissipation coating 18 may include nano-scale heat dissipation materials, and further may include nano-scale heat dissipation materials with high infrared emissivity, such as metal oxides and ceramics. Metal oxides may include aluminum oxide (Al2O3) and titanium oxide (TiO2), and ceramics may include aluminum nitride (AlN) nanoceramics and boron nitride (BN) nanoceramics.

[0078] On the basis of the above, a periodic structure can also be set on the surface of the nano heat dissipation coating 18 away from the LED display panel, such as nanoparticles, porous layers, etc. The rough or porous structure can increase the radiation surface area and improve the overall heat dissipation efficiency.

[0079] On the basis of the above, high thermal conductivity fillers, such as graphene, boron nitride, etc., can be added to the nano-scale heat dissipation material of the nano-heat dissipation coating 18. This can accelerate the conduction of heat from the box 7 to the surface of the nano-heat dissipation coating 18, and then dissipate it through radiation.

[0080] The thickness of the nano heat dissipation coating 18 may be 0.05 mm-0.5 mm. As an example, the thickness of the nano heat dissipation coating 18 may be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0081] An embodiment of the present application provides an LED display screen, which is provided with a nano-heat dissipation coating on the side of the housing away from the LED display panel. The nano-heat dissipation coating can enhance the radiation heat dissipation of infrared rays, efficiently convert heat into infrared radiation (especially the 8-13μm infrared band), and utilize the atmospheric window to achieve passive cooling. Under natural convection, the heat can be quickly dissipated to the surrounding environment, thereby significantly improving the heat dissipation efficiency of the LED display screen.

[0082] In some embodiments, reference Figure 1 、 Figures 3 and 4 As shown, the LED display screen may further include a sensor 10 and an intelligent heat dissipation control module 17. The sensor 10 is disposed in the accommodation space k, one end of the sensor 10 is connected to the bottom surface of the box 7, and the other end of the sensor 10 is suspended in the accommodation space k. The sensor 10 is used to monitor the temperature in the accommodation space k and transmit a signal to the intelligent heat dissipation control module 17. The intelligent heat dissipation control module 17 is disposed in the accommodation space k and is electrically connected to the sensor 10, the heat pipe heat dissipation structure, and the LED display panel, respectively. The intelligent heat dissipation control module 17 is used to receive the signal transmitted by the sensor 10 and make a judgment. When it is determined that the temperature in the accommodation space k is outside a threshold range, the intelligent heat dissipation control module 17 controls the working medium 16 to move in the heat pipe 15 to dissipate heat for the LED display panel, and / or controls the brightness of the LED display panel to decrease, and / or controls the power consumption of at least one LED to decrease. When it is determined that the temperature in the accommodation space k is within the threshold range, the working medium 16 is controlled to remain stationary in the heat pipe 15, and / or controls the brightness of the LED display panel to remain unchanged, and / or controls the power consumption of the LED to remain unchanged.

[0083] In practical applications, there is no specific limitation on the type of the sensor 10 . For example, the sensor 10 may be a chip or the like.

[0084] It should be understood that the intelligent heat dissipation control module 17 is arranged in the accommodation space k: Figure 1 、 Figures 3 and 4 As shown, the intelligent heat dissipation control module 17 can be connected to the bottom surface of the box 7 and to one end of the heat pipe 15. There is no specific limitation on the type of the intelligent heat dissipation control module 17. For example, the intelligent heat dissipation control module 17 can be a chip.

[0085] It should be noted that the embodiment of the present application can connect the sensor 10 to the control circuit of the intelligent heat dissipation control module 17, write a control program, set the temperature and heat dissipation strategy, etc., so as to realize functions such as heat dissipation control.

[0086] An embodiment of the present application provides an LED display screen, in which a sensor and an intelligent heat dissipation control module are provided in the accommodation space between the housing and the display panel. The temperature of the accommodation space (that is, the temperature of the LED display panel) can be monitored in real time by the sensor to ensure the accuracy of the detection. When the sensor detects that the temperature of the accommodation space is outside a threshold range, the intelligent heat dissipation control module is activated. At this time, the intelligent heat dissipation control module can adjust the heat dissipation strategy by adjusting the state of the working fluid in the heat pipe, and / or the brightness of the LED display panel, and / or the power consumption of the LED chip, to ensure that the LED display panel is always within the optimal working environment temperature range. While ensuring the normal operation of the LED display screen, it also reduces energy consumption and achieves the purpose of energy saving.

[0087] In some embodiments, the copper layer may have a density of 8.95 g / cc to 8.99 g / cc.

[0088] As an example, the density of the copper layer may be 8.95 g / cc, 8.96 g / cc, 8.97 g / cc, 8.98 g / cc, or 8.99 g / cc, etc. Further, the density of the copper layer may be selected to be 8.96 g / cc.

[0089] An embodiment of the present application provides an LED display screen, in which the copper layer has a high density, indicating that the bonding force between its atoms is strong, so that the copper layer has good thermal conductivity and can quickly absorb the heat of the LED chip in contact with it; at the same time, the copper layer has good mechanical properties, which can provide support for the LED chip, etc., so that it can be firmly installed on the composite thermal conductive substrate; in addition, the copper layer has good electrical conductivity, which can ensure the efficient transmission of current in the circuit of the copper layer, reduce the resistance loss during the transmission process, reduce heat generation, and ensure stable operation of the LED display screen.

[0090] In some embodiments, the copper layer has a thickness of 0.5 mm to 1.0 mm.

[0091] As an example, the thickness of the copper layer may be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1.0 mm, etc.

[0092] The embodiments of the present application provide an LED display screen. A suitable copper layer thickness can carry sufficient current to meet the power supply requirements of the LED chips in the LED display screen, avoid display anomalies caused by poor current transmission, such as uneven brightness and flickering, and is conducive to absorbing and quickly conducting away the heat generated by the LED chips, which can effectively reduce the temperature of the LED chips, prevent the LED chips from being degraded in performance, shortened in life, or even damaged due to overheating, improve the reliability and stability of the LED display screen, and extend its service life. At the same time, the suitable copper layer thickness can provide mechanical support for the LED chips, etc., so that they can be firmly mounted on the composite heat dissipation substrate. In addition, the suitable copper layer thickness can play a certain shielding role for electromagnetic signals within the LED display screen, reduce the generation and propagation of electromagnetic interference (EMI), help improve the electromagnetic compatibility (EMC) of the LED display screen, reduce its interference with other surrounding electronic devices, and also prevent the influence of external electromagnetic signals on the LED display screen itself, thereby ensuring display quality.

[0093] In some embodiments, the non-ceramic layer may have a strength greater than or equal to 500 MPa.

[0094] As an example, the strength of the ceramic layer may be 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, or the like.

[0095] The embodiment of the present application provides an LED display screen, wherein the ceramic layer has high strength, enabling it to withstand the weight of internal LED chips, circuits, etc., ensuring that it will not be deformed, cracked or damaged due to insufficient structural strength during assembly, transportation and use, thereby providing a stable physical support structure for the entire LED display screen; at the same time, it can effectively resist various external forces that may be exerted, such as collisions, extrusions, etc., reducing the risk of damage caused by external impacts, thereby improving the durability and reliability of the LED display screen and extending its service life; and the high-strength ceramic layer helps the LED display screen adapt to a wider range of environmental conditions, such as high temperature, high humidity or vibration environments, to ensure the normal operation of the LED display screen; in addition, sufficient strength can avoid cracking or damage of the ceramic layer due to mechanical stress, thereby reducing the occurrence of electrical faults such as insulation degradation and short circuits, ensuring that the electrical performance of the LED display screen is stable and reliable, and guaranteeing its normal operation.

[0096] In some embodiments, the ceramic layer may have a Rockwell hardness of HRA80-HRA100.

[0097] For example, the Rockwell hardness of a ceramic layer can be HRA80, HRA85, HRA90, HRA95, or HRA100. It should be noted that HRA80, used as an example, is a Rockwell hardness scale. The HRA scale uses a test force of 588.4N (60kgf) and a diamond cone indenter for testing, and 80 represents the hardness value derived from this specific test method. On the HRA scale, higher values ​​indicate higher hardness.

[0098] An embodiment of the present application provides an LED display screen having a ceramic layer with a very high Rockwell hardness, which enables the ceramic layer of the LED display screen to resist scratches and wear from external objects, maintain a smooth surface and integrity during long-term use, and reduce performance degradation or appearance damage caused by friction; at the same time, the high Rockwell hardness means that the ceramic layer can withstand greater pressure without obvious deformation or cracking, ensuring that it can provide stable support under various conditions and maintain the structural stability of the LED display screen; furthermore, the ceramic layer has good physical property stability, can adapt to high temperature, low temperature, and corrosive environments, and is not easily rapidly aged or damaged by environmental factors, thereby ensuring that the LED display screen can operate normally under various complex conditions and improving the reliability and service life of the LED display screen; in addition, the ceramic layer in this hardness range can be well matched with other components in the LED display screen, such as LED chips, in terms of mechanical properties, which helps to improve the integration and stability of the entire LED display screen.

[0099] In some embodiments, the thickness of the ceramic layer may be 0.8 mm to 1.5 mm.

[0100] As an example, the thickness of the ceramic layer may be 0.8 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.5 mm, etc.

[0101] The embodiment of the present application provides an LED display screen, in which the appropriate thickness enables the ceramic layer to have good insulation properties, ensuring that the ceramic layer can effectively electrically isolate different structures, prevent the occurrence of problems such as short circuits, and ensure the normal operation of the LED display screen; at the same time, the appropriate thickness can enable the ceramic layer to have certain capacitance characteristics, which helps to stabilize the charge distribution and electric field strength in the LED display screen, and has a positive effect on improving the display quality and stability; and the ceramic layer can provide stable support for the LED chip and copper layer while ensuring its own strength, ensuring that these structures will not be affected by deformation or damage of the ceramic layer during the assembly, transportation and use of the LED display screen, and can also enable the ceramic layer to have a certain impact resistance, and can withstand a certain degree of external force impact without breaking; in addition, the ceramic layer has good thermal conductivity, which helps to dissipate the heat generated by the LED chip during operation, reduce the occurrence of problems such as performance degradation and shortened life of the LED chip due to overheating, and greatly improve the performance and life of the LED display screen.

[0102] In a second aspect, an embodiment of the present application provides a method for preparing an LED display screen.

[0103] First, the present invention provides a method for preparing an LED display panel. Figure 5 As shown, the method for preparing an LED display panel may include the following steps:

[0104] S1. Provide a composite heat dissipation substrate including a metal layer and a non-metal layer.

[0105] The metal layer is located on one side of the non-metal layer.

[0106] S2. Welding a plurality of LEDs arranged in an array on a side of the metal layer away from the non-metal layer to obtain an LED display panel.

[0107] It should be noted that the metal layer, non-metal layer, LED, etc. in the embodiments of the present application can refer to the above embodiments and will not be repeated here.

[0108] refer to Figure 6 As shown, the above step S1. providing a composite heat dissipation substrate including a metal layer and a non-metal layer may include:

[0109] S11. Provide a copper sheet with a thickness of 0.8 mm and a ceramic sheet with a thickness of 1.2 mm.

[0110] S12. Clean the surfaces of the copper sheet and the ceramic sheet to remove oil stains and impurities on the surfaces of the copper sheet and the ceramic sheet.

[0111] S13. Sintering the cleaned copper sheet and ceramic sheet at a temperature of 800° C. to 1200° C. to obtain a composite heat dissipation substrate.

[0112] It should be noted that a high-temperature sintering process at temperatures between 800°C and 1200°C tightly bonds the copper sheet and ceramic sheet together, forming a copper layer and a ceramic layer, respectively. The copper layer is tightly bonded to one side of the ceramic layer, forming a single composite heat dissipation substrate. Because this composite heat dissipation substrate directly contacts the LED chip, it can directly absorb and conduct heat generated by the LED chip, improving the heat dissipation efficiency of the LED chip. The simple and easy implementation of this composite heat dissipation substrate facilitates industrial production and application.

[0113] The preparation method of the LED display panel provided in the embodiment of the present application enables the LED display panel to dissipate heat well in an outdoor environment, ensures its stable and efficient operation, and can extend its service life; in addition, the preparation method is simple and easy to implement, which is conducive to industrial production and application.

[0114] In some embodiments, reference Figure 7 As shown, after the above step S2, in which a plurality of LEDs arranged in an array are welded on a side of the metal layer away from the non-metal layer to obtain an LED display panel, an embodiment of the present application provides a method for manufacturing an LED display screen, which may include the following steps:

[0115] S3. Based on the size of the LED display panel and the layout design of the heat pipe cooling structure, drill a heat conduction hole that matches the heat pipe diameter of the heat pipe cooling structure on the back side of the composite heat dissipation substrate away from the LED. Then, connect one end of the heat pipe to the heat conduction hole and extend the other end of the heat pipe to the bottom surface of the box for connection to obtain the LED display.

[0116] Further, refer to Figure 8 As shown, the above step S3. According to the size of the LED display panel and the layout design of the heat pipe heat dissipation structure, after drilling a heat conduction hole that matches the heat pipe diameter of the heat pipe heat dissipation structure on the back side of the composite heat dissipation substrate away from the LED, one end of the heat pipe is connected to the heat conduction hole, and the other end of the heat pipe is extended to the bottom surface of the box for connection, the LED display screen may include:

[0117] S31. Using a die-casting process, aluminum alloy is made into a wave-shaped heat dissipation fin array and connected to the end of the heat pipe.

[0118] It should be noted that the temperature and pressure need to be controlled during the die-casting process to ensure that the heat sink fin array and the heat pipe are firmly connected.

[0119] S32. Based on the size of the LED display panel and the layout design of the heat pipe heat dissipation structure, drill a heat conduction hole that matches the diameter of the heat pipe on the back side of the composite heat dissipation substrate away from the LED, and connect the other end of the heat pipe to the heat conduction hole.

[0120] S33. Assemble the heat pipe with the heat dissipation fin array installed with the LED display panel to obtain an LED display screen.

[0121] The method for preparing an LED display screen provided in the embodiment of the present application connects the heat pipes to the heat conduction holes and the heat dissipation fin array respectively, which is simple and easy to implement and is conducive to industrial production and application.

[0122] In some embodiments, reference Figure 9 As shown, the above step S33 of assembling the heat pipe with the heat dissipation fin array installed with the LED display panel as a whole to obtain the LED display screen may include the following steps:

[0123] S331. Assemble the heat pipe with the installed heat dissipation fin array and the LED display panel as a whole, and then use a spraying method to evenly apply a layer of nano-heat dissipation material on the surface of the heat dissipation fin array away from the LED display panel. Then, dry it at a certain temperature to solidify the nano-heat dissipation material to obtain an LED display screen.

[0124] It should be noted that curing the nano heat dissipation material by drying at a certain temperature can enhance the bonding force between the nano heat dissipation coating and the heat dissipation fin array.

[0125] The method for preparing an LED display screen provided in the embodiment of the present application forms a nano-heat dissipation coating on the surface of the heat dissipation fin array away from the display panel through a spraying process. The method is simple and easy to implement, and is conducive to industrial production and application.

[0126] Only the content related to the invention is introduced here. The rest can be obtained by referring to the relevant technology and will not be described in detail here.

[0127] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An LED display screen, characterized in that: include: An LED display panel includes a composite heat dissipation substrate and a plurality of LEDs arranged in an array, wherein the composite heat dissipation substrate includes a metal layer and a non-metal layer, the metal layer is disposed on one side of the non-metal layer, the LEDs are soldered to a side of the metal layer away from the non-metal layer, and the composite heat dissipation substrate has at least one heat conduction hole penetrating the metal layer and the non-metal layer; A box body is fixed on a side of the composite heat dissipation substrate away from the LED, and a receiving space is enclosed between the box body and the composite heat dissipation substrate; A heat pipe heat dissipation structure is located in the accommodating space. The heat pipe heat dissipation structure includes a heat pipe and a working fluid. One end of the heat pipe is communicated with the heat conduction hole, and the other end of the heat pipe is connected to the box. The working fluid is filled in the heat pipe. When the temperature in the accommodating space is monitored to be outside a threshold range, the working fluid moves in the heat pipe to dissipate heat for the LED display panel. When the temperature in the accommodating space is monitored to be within the threshold range, the working fluid remains stationary in the heat pipe.

2. The LED display screen according to claim 1, characterized in that: The metal layer is a copper layer, and the non-metal layer is a ceramic layer.

3. The LED display screen according to claim 1 or 2, characterized in that: The box body includes a bottom surface, a first side surface, and a second side surface, one end of the first side surface is connected to one end of the second side surface through the bottom surface, and the other end of the first side surface and the other end of the second side surface are both connected to the LED display panel; The bottom surface is a heat dissipation fin array, which includes a plurality of sub-heat dissipation fins. Two adjacent sub-heat dissipation fins are connected end to end, and the shape of each sub-heat dissipation fin is non-linear.

4. The LED display screen according to claim 3, characterized in that: At least some of the sub-heat sink fins in the heat sink fin array are concave toward the LED display panel, and / or at least some of the sub-heat sink fins in the heat sink fin array are convex toward the LED display panel.

5. The LED display screen according to claim 3, characterized in that: The LED display screen further includes a nanometer heat dissipation coating, which is arranged on a side of the bottom surface of the box away from the LED display panel.

6. The LED display screen according to claim 1 or 2, characterized in that: The LED display screen also includes a sensor and an intelligent heat dissipation control module; The sensor is arranged in the accommodation space, one end of the sensor is connected to the bottom surface of the box, and the other end of the sensor is suspended in the accommodation space, and the sensor is used to monitor the temperature in the accommodation space and transmit a signal to the intelligent heat dissipation control module; The intelligent heat dissipation control module is arranged in the accommodating space, and the intelligent heat dissipation control module is electrically connected to the sensor, the heat pipe heat dissipation structure and the LED display panel respectively. The intelligent heat dissipation control module is used to receive the signal transmitted by the sensor and make a judgment. When it is judged that the temperature in the accommodating space is outside the threshold range, the working medium is controlled to move in the heat pipe to dissipate heat for the LED display panel, and / or the brightness of the LED display panel is controlled to be reduced, and / or the power consumption of at least one of the LEDs is controlled to be reduced, and when it is judged that the temperature in the accommodating space is within the threshold range, the working medium is controlled to be stationary in the heat pipe, and / or the LED display panel is controlled to maintain constant brightness, and / or the LED is controlled to maintain constant power consumption.

7. The LED display screen according to claim 2, characterized in that: The material of the copper layer includes electrolytic copper, and the density of the electrolytic copper is 8.95g / cc-8.99g / cc; And / or, the copper layer has a thickness of 0.5 mm to 1.0 mm.

8. The LED display screen according to claim 2, characterized in that: The strength of the ceramic layer is greater than or equal to 500 MPa; And / or, the Rockwell hardness of the ceramic layer is HRA80-HRA100; And / or, the thickness of the ceramic layer is 0.8 mm-1.5 mm.

9. A method for preparing an LED display screen, characterized in that: The steps include: A composite heat dissipation substrate comprising a metal layer and a non-metal layer is provided, and a plurality of LEDs arranged in an array are soldered to a side of the metal layer away from the non-metal layer to obtain an LED display panel; wherein the composite heat dissipation substrate has at least one heat conduction hole penetrating the metal layer and the non-metal layer; A box is fixed on the side of the composite heat dissipation substrate facing away from the LED; wherein a receiving space is enclosed between the box and the composite heat dissipation substrate; A heat pipe heat dissipation structure is formed in the accommodating space to obtain the LED display screen; wherein, the heat pipe heat dissipation structure includes a heat pipe and a working medium, one end of the heat pipe is communicated with the heat conduction hole, and the other end of the heat pipe is connected to the box, and the working medium is filled in the heat pipe. When the temperature in the accommodating space is monitored to be outside a threshold range, the working medium moves in the heat pipe to dissipate heat for the LED display panel, and when the temperature in the accommodating space is monitored to be within the threshold range, the working medium remains stationary in the heat pipe.

10. The method for preparing an LED display screen according to claim 9, characterized in that: The provision of a composite heat dissipation substrate including a metal layer and a non-metal layer includes: Provide metal materials and non-metal materials; The metal material and the non-metal material are sintered at a temperature of 800° C. to 1200° C. to form the composite heat dissipation substrate.

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