Heat sink, frame, and display device

Abstract

This application discloses a heat sink, a frame, and a display device, belonging to the field of heat dissipation technology. The backplate of the heat sink has a first surface and a second surface facing away from each other. Multiple sets of thermally conductive fin units are arranged at intervals on the first surface. Each set of fin units forms an array unit, and all array units are arranged in a cross-shaped or bifurcated structure. This allows for the diversion, boundary layer turbulence, and / or secondary flow guidance of the natural convection heat flow vertically upwards along the backplate. Along the natural convection airflow direction, all fin units are divided into at least two continuously arranged regions: an airflow inlet region near the bottom of the backplate and an airflow outlet region near the top of the backplate. The first arrangement density of fin units in the airflow inlet region is less than or equal to the second arrangement density of fin units in the airflow outlet region. By changing the vertical relationship between the airflow direction and the temperature gradient direction, the natural convection heat transfer coefficient is increased, thereby improving heat dissipation performance.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology, and in particular to a heat sink, a frame, and a display device. Background Technology

[0002] As a carrier of modern information display, light-emitting diode (LED) displays are evolving towards higher resolution, higher brightness, lower power consumption, and longer lifespan with the rapid development of display technology. These display technologies have led to a significant increase in power density per unit area, generating more heat. If this heat cannot be effectively dissipated, it will cause the screen temperature to rise, leading to display malfunctions and affecting display quality and the overall lifespan of the screen.

[0003] In related technologies, LED display modules are installed on the front of the frame, and vertical heat sinks (also known as heat dissipation fins) are designed on the back of the frame. The heat is radiated and dissipated by the "chimney effect" formed by the rising of hot air and the replenishment of cold air in natural convection, thereby transferring heat to the ambient air.

[0004] However, the heat dissipation effect of heat sinks is poor due to limitations such as the size of the heat sink and airflow. Therefore, there is an urgent need to provide a heat sink to improve heat dissipation performance. Summary of the Invention

[0005] This application provides a heat sink, a frame, and a display device, which can improve heat dissipation performance. The technical solution is as follows: In a first aspect, a heat sink is provided, including a back plate. The back plate has a first surface and a second surface facing away from each other. The second surface is used to attach to or support a fixed heat source. Multiple sets of fin units with thermal conductivity are arranged at intervals on the first surface. Each set of fin units forms an array unit, and all array units are arranged in a cross structure or a bifurcation structure. The cross structure or bifurcation structure serves as a fluid disturbance structure, which can divert, turbulentize, and / or guide the natural convection heat flow vertically upward along the back plate. Along the direction of the natural convection airflow, all the fin units are divided into at least two continuously arranged regions, namely an airflow inlet region near the bottom of the back plate and an airflow outlet region near the top of the back plate. The first arrangement density of the fin units in the airflow inlet region is less than or equal to the second arrangement density of the fin units in the airflow outlet region.

[0006] In a second aspect, a frame is provided, wherein one of the substrates of the frame is a heat sink as described in the first aspect above, and a plurality of display modules are disposed on the second surface of the heat sink.

[0007] Thirdly, a display device is provided, the display device including the frame as described in the second aspect above.

[0008] This application provides a heat sink, a frame, and a display device. According to the solution provided in this application, the heat sink includes a back plate with a first surface and a second surface facing away from each other. The second surface is used to attach to or support a fixed heat source. Multiple sets of thermally conductive fin units are spaced apart on the first surface. Each set of fin units forms an array unit, and all array units are arranged in a cross-shaped or bifurcated structure. The cross-shaped or bifurcated structure acts as a fluid disturbance structure, capable of diverting, boundary layer disturbance, and / or guiding secondary flow of the natural convection heat flow vertically upward along the back plate. Multiple fin units act as a primary surface disturbance structure, guiding airflow to impact the back plate and break the thermal boundary layer on the back plate surface. Along the natural convection airflow direction, all fin units are divided into at least two continuously arranged regions: an airflow inlet region near the bottom of the back plate and an airflow outlet region near the top of the back plate. The first arrangement density of fin units in the airflow inlet region is less than or equal to the second arrangement density of fin units in the airflow outlet region. The airflow inlet area employs a lower density of finned units to reduce inlet resistance and increase the amount of cold air supplied, while the airflow outlet area uses a higher density of finned units to enhance convective heat transfer in the high-temperature top zone. By setting multiple array units with different densities, the vertical relationship between the airflow velocity direction and the temperature gradient direction is altered, improving the synergy between the airflow velocity field and the temperature gradient field, increasing the natural convection heat transfer coefficient, and thus enhancing heat dissipation performance. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a front view of the arrangement of heat sinks provided in an embodiment of this application; Figure 2 This is a top view of the arrangement of heat sinks provided in an embodiment of this application; Figure 3 This is a front view of the structure of an X-shaped heat sink provided in an embodiment of this application; Figure 4 This is a top view of the structure of an X-shaped heat sink provided in an embodiment of this application; Figure 5 This is a schematic diagram of an array unit provided in an embodiment of this application; Figure 6 This is a top view of the fin unit distribution in an X-shaped array provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a fin unit provided in an embodiment of this application; Figure 8 This is a flowchart of a method for manufacturing a heat sink according to an embodiment of this application. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0012] It should be understood that "multiple" as mentioned in this application refers to two or more. In the description of this application, unless otherwise stated, " / " indicates "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist, for example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, to facilitate a clear description of the technical solutions of this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and that "first," "second," etc., do not necessarily imply differences.

[0013] Before providing a detailed explanation of the embodiments of this application, the relevant technologies of the embodiments of this application will be described first.

[0014] The maturity and widespread adoption of fine-pitch LEDs, Mini LEDs, Micro LEDs, and Chipboard (COB) flip-chip technologies have brought significant advantages to LED displays. For example, COB packaging can achieve higher contrast, better protection, and more uniform light emission; Mini / Micro LEDs can support seamless splicing of ultra-large screens and higher pixel density. However, these display technologies also increase power density per unit area. For instance, the power density of traditional surface-mount devices (SMD) packaged screens is approximately 200-400 watts per square meter (W / m²), while fine-pitch COB screens can reach 400-800 W / m² or even higher. This results in higher heat generation from the LED chips, driver integrated circuits (ICs), and power modules. If this heat cannot be effectively dissipated, the screen temperature can rise, reaching over 60°C, leading to accelerated light decay, color shift, increased dead light rate, and driver circuit failures, thus affecting display quality and the overall lifespan of the screen.

[0015] In related technologies, passive natural heat dissipation design is commonly used for the frame, accounting for over 80% of applications, such as outdoor fixed installations and high-end indoor applications. The main body of the frame is made of a single piece of high thermal conductivity aluminum alloy (e.g., die-cast aluminum). The LED display module (including the lamp panel and mask) is mounted on the front of the frame, and vertical heat sinks are designed on the back of the frame for natural convection cooling. Current LED display cooling systems also typically use metal heat sinks for natural convection cooling.

[0016] Taking the application of heat sinks in LED display cabinets as an example, such as Figure 1 and Figure 2 As shown, Figure 1 This is a front view of a heat sink arrangement provided in an embodiment of this application. Figure 2 This is a top view of a heat sink arrangement provided in an embodiment of this application. Multiple parallel straight heat sinks (typically arranged longitudinally to form vertical air channels) are integrally formed on the back of the casing. The heat sink surfaces are smooth or simply anodized, utilizing natural convection and radiation for heat dissipation. This parallel straight heat sink design relies on the "chimney effect," ensuring that the direction of the vertical air channels is consistent with gravity, forming natural convection from bottom to top. This parallel straight heat sink design relies on a continuously smooth heat sink surface, a well-developed thermal boundary layer, predominantly laminar airflow, a limited heat transfer coefficient, and a low Nusselt number in natural convection.

[0017] Figure 1 and Figure 2 The traditional heat sinks shown are parallel or vertical, distributed along the vertical direction (height) of the enclosure, parallel to the direction of airflow (i.e., the direction of natural convection airflow). The heat sinks are approximately 2 mm to 5 mm high, 2 mm to 5 mm thick, and spaced approximately 3 mm to 8 mm apart, forming multiple vertical air channels. During installation, the enclosure is placed vertically to ensure that the air channel direction is consistent with gravity, optimizing convection cooling efficiency.

[0018] With the increasing prevalence of Mini / Micro LEDs and the demand for high refresh rates, the heat load continues to increase. Traditional parallel straight heat sinks lead to the continuous development of the thermal boundary layer on the cabinet surface, resulting in predominantly laminar airflow with weak turbulence. In natural convection, the hot fluid rises slowly along the cabinet surface. The airflow velocity direction (from bottom to top of the cabinet surface) is mainly parallel to the cabinet surface, while the temperature gradient direction (from high temperature to low temperature) is mainly perpendicular to the cabinet surface, with the angle between the two approaching 90°. According to the field cooperation principle, the convective heat transfer is proportional to cosβ (β is the cooperation angle). When β→90°, cosβ→0, resulting in a low natural convection heat transfer coefficient, a thick thermal boundary layer on the cabinet surface, and minimal heat transfer effect.

[0019] Traditional parallel heat sinks, when used in high-power-density LED displays or operating in high-temperature or high-brightness environments, suffer from poor coordination between the airflow field and temperature gradient field due to their thick thermal boundary layer. This results in a large coordination angle between the two fields, with the field coordination number Fs typically less than 0.7, leading to a low natural convection heat transfer coefficient and low convection heat dissipation efficiency. The internal temperature of the enclosure easily exceeds 60°C to 70°C, affecting the lifespan of the LED chips and driver ICs, as well as color shift stability.

[0020] Based on the aforementioned technical problem of poor heat dissipation performance, this application provides a zoned, gradually changing heat sink based on the field synergy principle. Building upon traditional parallel straight heat sinks, it introduces multiple fin units continuously arranged along the natural convection airflow direction. These fin units are arranged in a cross-shaped, bifurcated, or biomimetic array, with the spacing between adjacent fin units forming slots. This design diverts, turbulentizes, and / or guides secondary flow of the hot fluid flowing along the natural convection airflow direction (i.e., the naturally convective hot fluid flowing vertically upwards along the backplate). By optimizing the fin structure, heat dissipation performance is improved. Figure 3 and Figure 4 As shown, Figure 3 This is a front view of the structure of an X-shaped heat sink provided in an embodiment of this application. Figure 4 This is a top view of the structure of an X-shaped heat sink provided in an embodiment of this application.

[0021] The heat sink includes a back plate 10, which has a first surface and a second surface facing away from each other. The second surface is used to attach to or support a fixed heat source. Multiple sets of fin units with thermal conductivity are arranged at intervals on the first surface. Each set of fin units forms an array unit. All array units are arranged in a cross structure or a bifurcation structure. The cross structure or bifurcation structure serves as a fluid disturbance structure, which can divert, turbulentize, and / or guide the natural convection heat flow vertically upward along the back plate. That is, the first surface of the back plate 10 is provided with multiple fin units that have thermal conductivity and are spaced apart, and the second surface of the back plate 10 is close to or provided with a heat source. The multiple array units formed by the layout structure of the multiple fin units have a cross structure or a branch structure, which plays a role in diverting, boundary layer turbulence and / or guiding secondary flow of the hot fluid along the direction of natural convection airflow. The angle between the setting direction of the fin units 20 and the direction of natural convection airflow is greater than 0, realizing staggered arrangement. In this way, the fin units themselves constitute a primary surface turbulence structure, guiding the airflow to impact the back plate and breaking the thermal boundary layer on the surface of the back plate.

[0022] Multiple array units composed of finned elements have slit, staggered, intersecting, or branching characteristics. Along the natural convection airflow direction, all finned elements are divided into at least two continuously arranged regions: an airflow inlet region near the bottom of the back plate 10 and an airflow outlet region near the top of the back plate 10. The first arrangement density of finned elements in the airflow inlet region is less than or equal to the second arrangement density of finned elements in the airflow outlet region. The airflow inlet region uses finned elements with a lower arrangement density to reduce airflow resistance and increase the amount of cold air supplied, while the airflow outlet region uses finned elements with a higher arrangement density to enhance convective heat transfer in the high-temperature top region.

[0023] Since the backplate is usually placed vertically, the air rises after being heated, so the airflow direction is usually from bottom to top. Based on this, by setting multiple array units with different densities, a sparse density variation is achieved in the airflow inlet and outlet areas, forming a gradual arrangement with sparser density at the bottom and denser density at the top. This changes the vertical relationship between the airflow velocity direction and the temperature gradient direction, making the airflow velocity field and the temperature gradient field more consistent, improving the synergy between the airflow velocity field and the temperature gradient field, increasing the natural convection heat transfer coefficient, and thus improving heat dissipation performance.

[0024] Compared with traditional parallel straight heat sinks, the heat sink provided in this application embodiment has an angle greater than 0 between the multiple fin units and the direction of natural convection airflow, which increases the disturbance to natural flow. Moreover, the inlet air resistance and outlet heat transfer enhancement are zoned and controlled along the natural convection airflow path (i.e., the direction of natural convection airflow), making the natural convection heat dissipation path more compatible with the temperature distribution on the back panel. This can specifically improve the synergistic relationship between the air velocity field and the temperature gradient field, thereby improving heat dissipation performance.

[0025] In one implementation, the spacing between adjacent fin units in the airflow inlet region is 250% of the fin height, and the spacing between adjacent fin units in the airflow outlet region is 50% of the fin height. The ratio between a first arrangement density and a second arrangement density is between 1 / 4 and 3 / 4; for example, the first arrangement density can be half of the second arrangement density. Each array unit includes multiple branches, and each branch includes multiple fin units. Adjacent branches form an intersecting or bifurcated structure, and the included angle between adjacent branches is greater than 30°.

[0026] In some embodiments, the first surface of the fin unit 20 or the backplate 10 is anodized or painted to improve thermal emissivity, for example, thermal emissivity > 0.9.

[0027] In some embodiments, the array units are one or more of the following: X-shaped, Y-shaped, V-shaped, U-shaped, fishbone-shaped, leaf-vein-shaped, tree-branch-shaped, forked, and wave-shaped.

[0028] The layout of multiple fin units forms multiple array units, with one set of fin units corresponding to one array unit. A set of fin units includes multiple fin units, and each array unit can be X-shaped, Y-shaped, V-shaped, U-shaped, fishbone-shaped, leaf-vein-shaped, tree-branch-shaped, wavy, or forked. Multiple array units can be any one of these types, or any combination of at least two of the above. Figure 3 and Figure 4 The array unit shown is X-shaped, with a slotted structure between each pair of fin units and a cross structure between each adjacent array, guiding oblique or transverse secondary flow through the cross and slotted structures.

[0029] The above Figure 3 and Figure 4 The X-shaped array units can be replaced with Y-shaped, herringbone, leaf vein, or branch-shaped units. For example, ... Figure 5 As shown, Figure 5 This is a schematic diagram of an array unit provided in an embodiment of this application. Figure 5 Figure A in the diagram shows several array cells in an X-shaped array. Figure 5 Figure B in the diagram shows several array cells in a Y-shaped array. Figure 5 Figure C illustrates several array units in a fishbone or leaf vein pattern. Among these, biomimetic branching structures such as fishbone, leaf vein, tree branch, wave, and forked structures can use vertical main fins as the main guiding structure, with oblique branch fins on both sides forming branches. The angle of the branch fins can be larger in the airflow inlet area and smaller or gradually change in the airflow outlet area, thus simultaneously accommodating functions such as air intake, air diversion, and enhanced heat transfer in high-temperature areas. In this way, multi-stage air diversion and turbulence can be formed by the combination of vertical main fins and oblique branch fins, improving heat dissipation performance.

[0030] In the example where the array units are X-shaped, the slotted structure between adjacent fin units or the fin units themselves are generally distributed in an X-shape on the backplate. The entire backplate can be equipped with one or more X-shaped array units depending on the backplate size. Similarly, the layout of Y-shaped, V-shaped, U-shaped, herringbone-shaped, leaf-vein-shaped, branch-shaped, wave-shaped, and forked array units can be found in the layout of the X-shaped array units, and will not be repeated here.

[0031] It should be noted that the array unit is not limited to X-shaped, Y-shaped, V-shaped, U-shaped, fishbone-shaped, leaf-vein-shaped, tree-branch-shaped, wave-shaped, or bifurcated, or one or more combinations thereof. It can also be other biomimetic flow diversion forms, as long as they can form flow diversion, boundary layer disturbance, and / or secondary flow induction effects along the natural convection airflow direction. This application does not limit this aspect in the embodiments.

[0032] This application provides various array units, which can be arranged in a cross, bifurcation or biomimetic flow splitting structure. There is a slotted structure between each two fin units, and a cross, bifurcation or biomimetic flow splitting structure between each adjacent array. This can guide oblique or lateral secondary flow, destroy the continuous thermal boundary layer, improve the synergy between the air velocity field and the temperature gradient field, and improve heat dissipation performance.

[0033] In some embodiments, as described above Figure 3 and Figure 4 As shown, in the X-shaped layout of the array units, a component is provided between every two adjacent X-shaped units to serve as a flow disruptor or diverter.

[0034] Multiple finned units are arranged in parallel and staggered patterns in an X-shape. A component can be added between each pair of adjacent X-shaped arrangements. This component can be a cylinder or a quasi-cylindrical shape. For example, the component is a cylinder of the same height and approximately 14 mm in diameter. This cylinder can act as a turbulence or flow divider, enhancing the turbulence or flow divider and increasing the heat exchange area to improve heat dissipation performance.

[0035] In some embodiments, each array unit includes multiple branches, and each branch includes multiple fin units; the first layout density or the second layout density includes at least one of the following: the spacing between adjacent fin units, the slot angle for indicating the angle between adjacent branches, and the slot density for indicating the number of array unit units.

[0036] The density of the airflow is reflected in at least one of the following: spacing, slit angle, and slit density. A larger spacing, a larger slit angle, or a lower slit density results in lower airflow resistance; conversely, a smaller spacing, a smaller slit angle, or a higher slit density leads to better convective heat transfer. This principle can be applied to the airflow inlet and outlet zones. For example, the airflow inlet zone can have a larger spacing, a larger slit angle, and a lower slit density to reduce airflow resistance and increase the intake of cold air (as natural convection air); the airflow outlet zone can have a smaller spacing, a smaller slit angle, and a higher slit density to enhance convective heat transfer in the high-temperature top zone, thereby improving heat dissipation performance.

[0037] For example, the above Figure 3 and Figure 4 The layout density of the airflow inlet and outlet regions shown has the same slit angle and slit density, that is, the included angle between adjacent branches is the same (an X-shaped array unit includes 2 branches), and the number of array units is the same (4 X-shaped array units are distributed perpendicular to the natural convection airflow direction). The spacing between the airflow inlet regions is smaller than the spacing between the airflow outlet regions.

[0038] In this embodiment, the multiple array units satisfy at least one gradual relationship: the spacing gradually decreases, the slot angle gradually decreases, and the slot density gradually increases along the natural convection airflow direction. Different spacing, slot angle, and slot density can all play a role in diverting, boundary layer turbulence, and / or guiding secondary flow of the hot fluid along the natural convection airflow direction. Different arrangement densities can be set by selecting one or more of the spacing, slot angle, and slot density, avoiding the difficulty of balancing flow resistance and heat transfer issues in single-zone parameter design, and improving the structural diversity and richness of the heat sink.

[0039] In some embodiments, the at least two consecutively arranged regions further include a central airflow region, where the third arrangement density of the fin units in the central airflow region is between the first arrangement density and the second arrangement density, and the first arrangement density, the third arrangement density and the second arrangement density change in a stepwise manner or in a continuous gradual manner.

[0040] In this embodiment, along the natural convection airflow direction, multiple array units can be divided into an airflow inlet region, an airflow middle region, and an airflow outlet region. The airflow inlet region is used to introduce cold air, employing fin units with a lower density (reflected in larger spacing, larger slit angle, and / or, lower slit density) to reduce airflow resistance and increase the amount of cold air supplied. The airflow middle region is used to guide oblique or lateral secondary flow, employing array units with cross, bifurcation, or biomimetic flow-diverting structures to improve airflow mixing capacity. The airflow outlet region corresponds to a higher temperature area, employing fin units with a higher density (reflected in smaller spacing, smaller slit angle, and / or, higher slit density) to enhance convective heat transfer in the high-temperature top region.

[0041] For example, the above Figure 3 and Figure 4 The arrangement density of the airflow inlet, airflow middle, and airflow outlet zones shown is based on the spacing between adjacent fin units, which exhibits a continuous, gradual change in spacing. Alternatively, the spacing between adjacent fin units in the airflow inlet zone can be set to a first spacing, the spacing in the airflow middle zone to a second spacing, and the spacing in the airflow outlet zone to a third spacing, with the first, second, and third spacing decreasing sequentially in a step-like manner.

[0042] Similarly, the slot angle and slot density can be arranged with reference to the design concept of the spacing between adjacent fin units. The arrangement density can be distinguished by one, two, or all of the partition parameters of spacing, slot angle, and slot density. This application embodiment does not limit this.

[0043] For example, such as Figure 6 As shown, Figure 6 This is a top view of a fin unit distribution in an X-shaped array provided in an embodiment of this application. Figure 6The partitioned gradient spoiler array unit is shown. To facilitate comparison of the differences in slot angle and slot density between different partitions, Figure 6 The spacing between adjacent fin units is not shown. Figure 6 Figure A shows the layout density of the airflow outlet area. Figure 6 Figure B in the diagram shows the distribution density in the middle region of the airflow. Figure 6 Figure C in the diagram shows the density of the airflow inlet area, which is determined by... Figure 6 It can be seen that the slit angle decreases sequentially and the slit density increases sequentially in the airflow inlet region, the airflow middle region, and the airflow outlet region. Figure 6 What is shown is not a simple single X-shaped array unit, but a gradual arrangement that transitions from "low-resistance introduction" to "enhanced turbulent heat transfer" along the natural convection airflow path, thereby improving heat dissipation performance.

[0044] Compared with traditional parallel straight heat sinks, the embodiments of this application not only add fin units that disturb the airflow, but also perform zoned control of the airflow inlet resistance, airflow mixing in the middle airflow area and enhanced heat transfer in the airflow outlet area along the natural convection airflow path (i.e., the direction of natural convection airflow), which can further improve the synergistic relationship between the airflow velocity field and the temperature gradient field in a targeted manner.

[0045] In this embodiment, since the backplate is typically placed vertically, the air rises after being heated, so the airflow direction is usually from bottom to top. Based on this, an airflow inlet area, an airflow middle area, and an airflow outlet area are set along the natural convection airflow direction, and the spacing, slit angle, and slit density of each section are made to change continuously or in a stepped manner. This reduces flow resistance in the airflow inlet area, enhances airflow mixing and guides secondary flow in the airflow middle area, changes the flow direction and enhances field synergy, and strengthens high-temperature heat transfer in the airflow outlet area. This makes the natural convection heat dissipation path more compatible with the backplate temperature distribution and improves heat dissipation performance.

[0046] In some embodiments, at least a portion of the fin unit surface is provided with a micro-turbulence structure, the micro-turbulence structure including protrusions and / or cavities, the protrusions including at least one of needle-like microfins, roughened textures, corrugations, fins, coatings, ribs and bumps, and the cavities including at least one of pits, grooves, blind holes and through holes.

[0047] Multiple fin units themselves serve as primary surface perturbation structures, and at least some of the fin units also have secondary surface perturbation structures (i.e., micro-perturbation structures) on their surfaces. The secondary surface perturbation structures can be any one or any combination of at least two of the following: roughening textures, ripples, fins, coatings, ribs, bumps, pits, grooves, blind holes (also known as micropores), and through holes.

[0048] It should be noted that the density of the secondary surface disturbance structure in the airflow outlet region is higher than that in the airflow inlet region. The secondary surface disturbance structure can be set only in the fin units located in the airflow outlet region or in local high heat flux regions, or it can cover all fin units; this embodiment of the application does not impose any limitations on this.

[0049] The orientation of the secondary surface disturbance structures (including protrusions and cavities) must meet the following condition: the angle between them and the direction of the natural convection airflow must be greater than 0. The secondary surface disturbance structures can be arranged perpendicular to the direction of the natural convection airflow, obliquely to the direction of the natural convection airflow, or along the gap direction between adjacent fin units. The density of the secondary surface disturbance structures on the fin units can gradually increase from the airflow inlet area to the airflow outlet area.

[0050] For example, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of a fin unit provided in an embodiment of this application. Figure 7 The diagram shows the direction of heat conduction from the backplate 10 to the fin unit 20. Figure 7 The image shows some of the surface disturbance structures of the fin unit 20, such as oblique ribs, pits, bumps, micropores, etc. The fin unit 20 is connected to the back plate 10 by an insert.

[0051] It should be noted that the above Figures 1-7 These are all illustrative examples and do not represent specific actual dimensions or installation locations, nor do they constitute a structural limitation on the heat sink provided in the embodiments of this application.

[0052] In related technologies, traditional parallel straight heat sinks have low convective heat dissipation efficiency and poor adaptability. When the power of the LED display increases, there is a conflict between increasing the number of heat sinks and maintaining convective heat dissipation efficiency. Moreover, the surface of the heat sink has no turbulence structure, the turbulence intensity is weak, and the heat dissipation performance is poor.

[0053] In this embodiment, a synergistic design of low flow resistance in the airflow inlet region, strong mixing in the airflow mid-region, and enhanced heat transfer in the airflow outlet region is utilized to make the airflow velocity field and temperature gradient field more consistent. A primary surface turbulence structure (main turbulence structure) guides oblique or transverse secondary flows. A secondary surface turbulence structure (micro-turbulence structure) is added on top of the main turbulence structure to break or disrupt the thermal boundary layer, reduce the synergistic angle, increase the effective heat transfer area, improve the heat transfer efficiency per unit area, and guide local micro-vortices.

[0054] Furthermore, the fin unit 20 can be a composite fin made of dissimilar materials or a surface treated with high emissivity to improve local thermal conductivity and radiative heat dissipation performance.

[0055] In this embodiment, the surface of the fin unit 20 is provided with a secondary surface disturbance structure, which is combined with at least two sections. That is, the secondary surface disturbance structure can be used in combination with the main disturbance structure such as X-shaped, Y-shaped, V-shaped, U-shaped, fishbone-shaped, leaf vein-shaped, tree branch-shaped, wave-shaped, or bifurcation-shaped. For example, the fin unit in the airflow inlet area can be provided with only a few ribs or no secondary surface disturbance structure to reduce the airflow resistance; the middle airflow area is provided with oblique ribs or pit array units to enhance airflow mixing; and the airflow outlet area is provided with a higher density of micropore, pit, or convex array units to continuously disrupt the thermal boundary layer.

[0056] In this embodiment, multiple array units are divided into an airflow inlet region, an airflow middle region, and an airflow outlet region. The spacing, slot angle, slot density, or secondary surface disturbance structures on the surface of adjacent fin units in different regions are configured differently. In one optional configuration, the spacing and slot angle of the airflow inlet region are greater than those of the airflow middle region or the airflow outlet region to reduce inlet resistance (i.e., reduce flow resistance when cold air enters the heat dissipation channel on the backplate) and increase the amount of cold air supplied. The airflow middle region uses a transitional spacing or transitional slot angle to enhance airflow mixing, guiding lateral or oblique secondary flow through intersecting, branching, or staggered fin units, thus disrupting the continuous thermal boundary layer. Due to the increased air temperature and thickened boundary layer, the airflow outlet region employs a smaller spacing, higher slot density, or a denser secondary surface disturbance structure (i.e., a denser secondary surface disturbance structure) to enhance the convective heat transfer capacity of the high-temperature top region.

[0057] For example, as described above Figure 1 and Figure 2 As shown, the height of traditional parallel straight heat sinks can be set to 3mm, the parallel spacing to 3mm, and they are arranged parallel to each other on the backplate along the natural convection airflow direction. This application provides an X-shaped array unit with gradually changing partitions, such as... Figure 3 and Figure 4 As shown, the spacing of the airflow inlet area can be set to 6mm, with a larger spacing and a larger opening angle to reduce airflow resistance; the spacing and opening angle of the middle airflow area gradually transition to guide the lateral or oblique secondary flow; the spacing of the airflow outlet area can be reduced to 3mm, and secondary surface turbulence structures such as ribs, pits or micropores can be added to enhance the heat exchange capacity of the top high-temperature area, thus improving heat dissipation performance.

[0058] In some embodiments, the area of ​​the heat sink is positively correlated with the number of fin units. That is, for a larger heat sink area, more fin units can be arranged to improve heat dissipation performance.

[0059] In this embodiment, when the backplate area or the power density per unit area increases, the number of array units can be appropriately increased, that is, the slot density can be increased, and the spacing, slot angle, slot density, and density of the secondary surface turbulence structure in the airflow inlet area, airflow middle area, and airflow outlet area can be adjusted. Multiple array units maintain a gradual arrangement along the natural convection airflow direction, transitioning from "low-resistance introduction" to "enhanced turbulence heat transfer," to improve heat dissipation performance.

[0060] In some embodiments, the fin unit 20 and the back plate 10 satisfy at least one of the following conditions: the thermal conductivity and / or thermal emissivity of the fin unit and the back plate are different; the fin unit and the back plate are made of different substrate materials; or the fin unit or the back plate is a composite thermally conductive material.

[0061] In this embodiment, the fin unit 20 can be made of a material with a thermal conductivity or thermal emissivity greater than that of the backplate 10. Alternatively, the fin unit 20 can be made of a material with both a thermal conductivity and thermal emissivity greater than that of the backplate 10. The fin unit 20 can also be made of a composite thermally conductive material, such as copper, aluminum-copper composite materials, graphite thermally conductive sheets, graphene composite thermally conductive sheets, or metal sheets with a high emissivity coating. That is, the fin unit can be made of a different high thermal conductivity material, high emissivity material, or composite thermally conductive material than the backplate, forming a heterogeneous composite fin unit. For example, the backplate is made of die-cast aluminum, and multiple fin units are made of aluminum, copper, aluminum-copper composite materials, graphite, graphite composite materials, graphene composite materials, ceramic thermally conductive materials, or metal materials with a high emissivity coating to improve radiative heat dissipation capacity. In this way, the local heat conduction, diffusion, and radiation capabilities can be improved without significantly changing the backplate structure and cost. The aforementioned heterogeneous composite structure can improve the synergy between the air velocity field and the temperature gradient field, reduce the synergy angle, and increase the field synergy number, thereby improving the efficiency of natural convection heat transfer.

[0062] Compared with a single equally spaced X-shaped array unit, the embodiments of this application introduce a gradual change in the layout density of the airflow inlet area, the airflow middle area, and the airflow outlet area. Combined with a secondary surface turbulence structure, array units with cross, bifurcation, or biomimetic diversion structures, and heterogeneous composite fin units, the structure of the heat sink has a larger adjustment range and a wider application coverage, thus improving the application scenarios of the heat sink.

[0063] Compared with traditional parallel straight heat sinks and single equidistant X-shaped array units, the heat sink provided in this application embodiment has better technical performance in the following indicators: maximum temperature of LED display screen, average temperature of LED display screen, surface temperature uniformity of LED display screen, natural convection heat transfer coefficient, pressure drop or flow resistance, and temperature rise of LED chip and driver IC under the same power. As shown in Table 1 below.

[0064] Table 1

[0065] In Table 1 above, control group A uses traditional parallel straight heat sinks, control group B uses a single equally spaced X-shaped array unit, and experimental group 2 uses the heat sink provided in the embodiments of this application. To facilitate comparison of the heat dissipation effect of different arrangement densities, Table 1 also shows experimental group 1, in which the arrangement density of fin units in the airflow inlet area is greater than that in the airflow outlet area. Compared with control groups A and B, experimental group 1 can also improve the heat dissipation effect, which also shows that even when the first arrangement density is equal to the second arrangement density, the heat dissipation effect can still be improved when using array units arranged in a cross structure or a bifurcation structure. As can be seen from Table 1, the heat dissipation effect of experimental group 2 is better than that of experimental group 1, which also shows the reliability of the theory: the airflow inlet area uses fin units with a lower arrangement density to reduce airflow resistance and increase the amount of cold air supplied, and the airflow outlet area uses fin units with a higher arrangement density to enhance convective heat transfer in the high-temperature area at the top. Compared with control group A, experimental group 2 in Table 1 above shows a 18.1% reduction in maximum temperature, a 117% increase in convective heat transfer coefficient, and a 45.5% increase in field synergy.

[0066] It should be noted that the various improvements provided above—gradual zoning, multi-segment zoning (airflow inlet zone, airflow middle zone, airflow outlet zone), secondary surface perturbation structure, multi-array units (X-type, Y-type, V-type, U-type, fishbone type, leaf vein type, tree branch type, wave type, or forked type), and heterogeneous composite structure—can be implemented individually or in combination to form heat dissipation optimization schemes with different power densities per unit area, different backplate sizes, and different installation environments. This application does not limit these implementations. Specifically, the primary surface perturbation structure (main perturbation structure) is used for flow diversion and perturbation, the secondary surface perturbation structure (micro-perturbation structure) is used to break or disrupt the thermal boundary layer, and the heterogeneous composite structure is used to improve local heat conduction and thermal radiation capabilities.

[0067] In some embodiments, multiple fin units are integrally formed with the backplate 10, or multiple fin units are fixedly connected to the first surface of the backplate 10 by means of inlay casting, pressing, welding, screwing, riveting, snap-fitting or thermally conductive adhesive.

[0068] The fin unit 20 can be integrally die-cast with the backplate 10 using the same material (i.e., integrally formed from the same material). Alternatively, it can be made of a different high thermal conductivity material, high radiation material, or composite thermal conductivity material than the backplate 10, and can be installed as an independent component, and fixedly connected to the first surface of the backplate 10 by embedding, pressing, welding, screwing, riveting, snap-fitting, or thermally conductive adhesive.

[0069] The embodiments of this application do not limit the connection method between the fin unit and the backplate, thereby improving the diversity and adaptability of the heat sink manufacturing process.

[0070] In some embodiments, the height of the fin unit 20 is between 2 mm and 10 mm, the thickness of the fin unit 20 is between 2 mm and 6 mm, and the spacing between adjacent fin units is 50% to 300% of the height of the fin unit.

[0071] The fin unit has a relatively small thickness, approximately 2mm to 6mm, and its shape can be quadrilateral, such as parallelogram, trapezoid, approximately parallelogram, rectangle, square, etc. This application does not limit this aspect.

[0072] In one feasible approach, the length of the fin unit along the branching direction can be 5mm to 20mm, the height h of the fin unit can be 2mm to 8mm, the thickness δ can be 1mm to 6mm, and the slot width s (i.e., the spacing between adjacent fin units) can be 50% to 300% of the fin height. For example, the length of the fin unit is about 10mm, the height h and thickness δ are about 3mm, the slot width s in the airflow inlet region is 250% of the fin height, and the slot width s in the airflow outlet region is 50% of the fin height.

[0073] In some embodiments, when there are local areas on the second surface that do not meet the temperature distribution pattern, the arrangement density of multiple fin units distributed in the local area is greater than the arrangement density of the partition in which the local area is located.

[0074] Since backplates are typically placed vertically, heated air rises, resulting in an upward airflow. The temperature distribution on the backplate generally follows this bottom-up increasing pattern. However, there may be localized areas with a large number of components, causing the temperature in these areas to exceed the average temperature of their respective zones; in other words, these localized areas do not conform to the temperature distribution pattern. To address this, a higher density of fin units can be used. For example, if a localized area is located in the airflow inlet region, and the unit density in that area is greater than the initial density, smaller spacing, smaller slot angles, larger slot density, and / or a higher density of secondary surface turbulence structures can be used. In other words, any one or at least two of these combinations can be selected to improve local heat dissipation performance and expand the applicability of the heat sink.

[0075] For example, the backplate is made of die-cast aluminum, and multiple fin units in local high heat flux areas or airflow outlet areas are made of copper, aluminum-copper composite, graphite composite, or metal materials with high emissivity coatings to improve local heat conduction and radiative heat dissipation capabilities.

[0076] It should be noted that the number of zones in this embodiment is not limited to three sections: the airflow inlet zone, the airflow middle zone, and the airflow outlet zone. It can also be divided into four or more sections, and this embodiment does not impose any restrictions on this. The spacing, slit angle, slit density, and / or the density of the secondary surface turbulence structure between each zone can vary in a stepwise manner, gradually change continuously, or vary locally according to the heat source distribution.

[0077] Based on the heat sink provided in the above embodiments, this application also provides a frame, which is applied to a display device. One substrate of the frame is a heat sink as described in any of the above embodiments, and a plurality of display modules are disposed on the second surface of the heat sink. While maintaining the advantages of the current frame, the natural convection heat dissipation efficiency can be further improved, making it suitable for high power density LED display scenarios, as well as for operation in high temperature environments or high brightness environments.

[0078] In some embodiments, the frame may be a display screen housing, a display control box, a power supply box, a splicing screen substrate, or a display module housing.

[0079] The frame can be an LED display cabinet, an LED control box, a power supply box, a splicing screen substrate, an outdoor display module housing, or other electronic device housings that rely on natural convection for heat dissipation; this application does not limit the scope of the embodiments.

[0080] Taking an LED display cabinet as an example, the LED display cabinet includes a main body (i.e., a back panel) and multiple fin units disposed on the back of the main body (i.e., the first surface of the back panel). The main body can be made of high thermal conductivity aluminum alloy, die-cast aluminum, or other structural materials suitable for LED display cabinets. The multiple fin units, following the natural convection airflow direction, include at least an airflow inlet area, an airflow middle area, and an airflow outlet area, and at least one of the following is different: spacing, slit angle, slit density, or secondary surface turbulence structure. In one implementation, since the back panel is usually placed vertically, the air rises after being heated, so the airflow direction is usually from bottom to top. Based on this, the slit angle or spacing of the airflow inlet area can be set larger than that of the airflow outlet area, forming a gradually changing arrangement with sparser slits at the bottom and denser slits at the top, to reduce airflow resistance. The airflow outlet area is provided with a higher slit density or secondary surface turbulence structure to enhance heat transfer. This can enhance the convective heat dissipation efficiency of the LED display cabinet, reduce the maximum and average temperature of the LED display, improve the surface temperature uniformity, natural convection heat transfer coefficient, pressure drop or flow resistance of the LED display, thereby ensuring the working stability of the LED chip, driver IC and power module.

[0081] The frame and heat sink embodiments provided in the above embodiments belong to the same concept. For the specific structure and technical effects of the above embodiments, please refer to the heat sink embodiment section, which will not be repeated here.

[0082] Based on the frame provided in the above embodiments, this application also provides a display device, which includes the frame as described in any of the above embodiments.

[0083] In some embodiments, the display device may employ common cathode power supply, high-efficiency driver ICs, and high-quality LED chips to reduce heat generation at the source.

[0084] The display device and the heat sink embodiment provided in the above embodiments belong to the same concept. For the specific structure and technical effects of the above embodiments, please refer to the heat sink embodiment section, which will not be repeated here.

[0085] Based on the heat sink provided in the above embodiments, this application also provides a method for manufacturing the heat sink, such as... Figure 8 As shown, Figure 8 This is a flowchart of a method for manufacturing a heat sink according to an embodiment of this application.

[0086] S101, Forming the backplate.

[0087] S102. Multiple sets of heat-conducting fin units are arranged at intervals on the first surface of the backplate to form a heat sink.

[0088] The fin units can be formed through die casting, computer numerical control (CNC) machining, insert molding, laser processing, etching, stamping, sandblasting, or coating processes. The backplate has a first surface and a second surface facing away from each other. The second surface is used to attach or support a fixed heat source, and multiple sets of thermally conductive fin units are arranged at intervals on the first surface. Each set of fin units forms an array unit, and all array units are arranged in a cross or bifurcated structure. The cross or bifurcated structure acts as a fluid disturbance structure, which can divert, turbulentize, and / or guide the natural convection heat flow vertically upward along the backplate. Along the natural convection airflow direction, all fin units are divided into at least two continuously arranged regions, namely an airflow inlet region near the bottom of the backplate and an airflow outlet region near the top of the backplate. The first arrangement density of fin units in the airflow inlet region is less than or equal to the second arrangement density of fin units in the airflow outlet region.

[0089] In some embodiments, the manufacturing method further includes: forming a micro-turbulence structure on the surface of at least a portion of the fin units by molding, laser processing, etching, stamping, sandblasting, or coating processes. The surface turbulence structure includes protrusions and / or cavities. The protrusions include at least one of roughened textures, corrugations, fins, coatings, ribs, and bumps. The cavities include at least one of pits, grooves, blind holes, and through holes.

[0090] In some embodiments, the manufacturing method further includes: the backplate and the fin unit are integrally formed by high-pressure die casting, extrusion, CNC machining or additive manufacturing; or the fin unit is fixedly connected to the first surface of the backplate by inlay casting, pressing, welding, screwing, riveting, snap-fitting or thermally conductive adhesive.

[0091] For example, for dissimilar composite fin units, fin units with copper, graphite composite or high emissivity coatings can be prepared first, and then fixedly connected to the first surface of the back plate by embedding, pressing, welding, screwing, riveting, snap-fitting or thermally conductive adhesive.

[0092] The manufacturing method provided in the above embodiments and the heat sink embodiments belong to the same concept. For the specific structure and technical effects of the above embodiments, please refer to the heat sink embodiments section, which will not be repeated here.

[0093] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0094] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0095] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A heat sink, characterized in that, Includes a back plate, which has a first surface and a second surface facing away from each other. The second surface is used to attach or support a fixed heat source, and multiple sets of fin units with thermal conductivity are arranged at intervals on the first surface. Each group of fin units forms an array unit, and all array units are combined in an overall cross structure or bifurcation structure; the cross structure or bifurcation structure serves as a fluid disturbance structure, which can achieve flow diversion, boundary layer disturbance and / or secondary flow guidance for the natural convection thermal fluid vertically upward along the back plate. Along the natural convection airflow direction, all the fin units are divided into at least two continuously arranged regions, namely an airflow inlet region near the bottom of the back plate and an airflow outlet region near the top of the back plate; the first arrangement density of the fin units in the airflow inlet region is less than or equal to the second arrangement density of the fin units in the airflow outlet region.

2. The heat sink as described in claim 1, characterized in that, The array units are in one or more of the following shapes: X-shaped, Y-shaped, V-shaped, fishbone-shaped, leaf-vein-shaped, tree-branch-shaped, forked, and wave-shaped. In the X-shaped layout of the array units, a component is provided in the gap between every two adjacent X-shaped units to serve as a flow disruptor or diverter.

3. The heat sink as described in claim 1 or 2, characterized in that, The surface of the fin unit is provided with a micro-turbulence structure, which includes protrusions and / or cavities. The protrusions include at least one of roughened textures, ripples, fins, ribs, and bumps. The cavities include at least one of pits, grooves, blind holes, and through holes.

4. The heat sink as described in any one of claims 1-3, characterized in that, Both the fin unit and the back plate must satisfy at least one of the following conditions: The thermal conductivity and / or thermal emissivity of the fin unit and the back plate are different. The fin unit and the back plate are made of different substrate materials, and the fin unit or the back plate is a composite thermally conductive material.

5. The heat sink as described in any one of claims 1-3, characterized in that, The height of the fin unit is between 2 mm and 10 mm, the thickness of the fin unit is between 2 mm and 6 mm, and the spacing between adjacent fin units is 50% to 300% of the height of the fin unit.

6. The heat sink as described in any one of claims 1-3, characterized in that, The at least two continuously arranged regions also include a central airflow region, where the third arrangement density of the fin units in the central airflow region is located between the first arrangement density and the second arrangement density, and the first arrangement density, the third arrangement density and the second arrangement density change in a stepwise manner or in a continuous gradual manner.

7. The heat sink as described in any one of claims 1-3, characterized in that, The multiple fin units are integrally formed with the back plate, or the multiple fin units are fixedly connected to the first surface of the back plate by means of inlay casting, pressing, welding, screwing, riveting, snap-fitting or thermally conductive adhesive.

8. A frame, characterized in that, One of the substrates of the frame is a heat sink as described in any one of claims 1-7, and a plurality of display modules are disposed on the second surface of the heat sink.

9. The frame as described in claim 8, characterized in that, The frame can be a display screen housing, a display control box, a power supply box, a splicing screen substrate, or a display module housing.

10. A display device, characterized in that, The display device includes a frame as described in claim 8 or 9 above.

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