A heat dissipation assembly

Abstract

A heat dissipation assembly, comprising a liquid cooling plate, a first sub-plate, a second sub-plate, a third sub-plate, a first heat generating component mounted on the first sub-plate, a second heat generating component mounted on the second sub-plate, and a third heat generating component mounted on the third sub-plate; the first sub-plate, the second sub-plate and the third sub-plate are independently mounted on the liquid cooling plate; the first sub-plate, the second sub-plate and the third sub-plate are electrically connected with each other; the first heat generating component, the second heat generating component and the third heat generating component comprise different heat generating devices; the first sub-plate, the second sub-plate and the third sub-plate are in contact with the liquid cooling plate through different heat conduction structures. The utility model can balance heat dissipation, avoid mechanical stress problems caused by temperature difference, and because each sub-plate is independently mounted, it can be individually disassembled and replaced, so the production and maintenance cost is low.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation components for printed circuit boards (PCBs), and more specifically, to a heat dissipation component. Background Technology

[0002] The common approach to heat dissipation components is to fix the entire PCB board onto a liquid cooling plate, with all heat-generating components on the PCB board dissipating heat through contact with the liquid cooling plate via the same thermally conductive material. However, this design suffers from uneven heat dissipation, leading to mechanical stress problems due to temperature differences. Furthermore, fixing the entire PCB board requires high structural rigidity, and the failure of a single component necessitates replacing the entire PCB board and liquid cooling plate, resulting in high production and maintenance costs. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a heat dissipation component that can achieve balanced heat dissipation, avoid mechanical stress problems caused by temperature differences, and has low production and maintenance costs, in order to address the above-mentioned deficiencies of the prior art.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to construct a heat dissipation component, the heat dissipation component including a printed circuit board and a liquid cooling plate, the printed circuit board including a first sub-board, a second sub-board, a third sub-board, a first heating component mounted on the first sub-board, a second heating component mounted on the second sub-board, and a third heating component mounted on the third sub-board. The first sub-board, the second sub-board, and the third sub-board are independently mounted on the liquid cooling plate; the first sub-board, the second sub-board, and the third sub-board are electrically connected to each other; The first heating component, the second heating component, and the third heating component each include different heating devices; the first sub-board, the second sub-board, and the third sub-board are in contact with the liquid cooling plate through different thermally conductive structures. In the heat dissipation assembly of this utility model, the first sub-plate is fixed to a first region of the liquid cooling surface of the liquid cooling plate by a first fixing device; the second sub-plate is fixed to a second region of the liquid cooling surface of the liquid cooling plate by a second fixing device; the third sub-plate is fixed to a third region of the liquid cooling surface of the liquid cooling plate by a third fixing device; the first region, the second region and the third region do not overlap with each other.

[0005] In the heat dissipation assembly of this utility model, the first sub-board is separated from the first region by a first distance, the second sub-board is separated from the second region by a second distance, and the third sub-board is separated from the third region by a third distance. The first distance matches the height of the first heating element; the second distance matches the height of the second heating element; and the third distance matches the height of the third heating element.

[0006] In the heat dissipation assembly of this utility model, a first heat-conducting structure is provided between the first heat-generating component and the first region; a second heat-conducting structure is provided between the second heat-generating component and the second region; and a third heat-conducting structure is provided between the third heat-generating component and the third region.

[0007] In the heat dissipation assembly described in this utility model, the first heat-generating assembly includes a filter inductor and a filter peripheral circuit. The first thermally conductive structure includes a first thermally conductive paste coated on the filter inductor and a first thermally conductive sheet disposed on the fuse of the filter peripheral circuit; The first fixing device is a first fixing screw; The first area is in contact with the first thermal paste and the first thermal sheet, respectively.

[0008] In the heat dissipation assembly described in this utility model, the second heat-generating component includes a power inductor; The second thermally conductive structure includes a second thermally conductive paste coated on the power inductor; The second fixing device is the second fixing screw; The second area comes into contact with the second thermal paste.

[0009] In the heat dissipation assembly described in this utility model, the third heat-generating assembly includes a power switch group, a first bus capacitor group, a second bus capacitor group, and a control circuit. The power switch group is located in the middle of the third sub-board and includes multiple power switches. The first bus capacitor group and the second bus capacitor group are arranged in an L-shape around the power switch group. The third thermal conductive structure includes a second thermal conductive sheet disposed on the power switch assembly, silicone grease coated on the second thermal conductive sheet, a third thermal conductive sheet disposed on the first bus capacitor assembly, and a fourth thermal conductive sheet disposed on the second bus capacitor assembly. The third fixing device includes a third fixing screw; Each of the power switches is fixed to the third region by a fourth fixing screw.

[0010] In the heat dissipation assembly of this utility model, the third region includes a first sub-region, a second sub-region, and a third sub-region. The first sub-region contacts the second thermal conductive sheet and the silicone grease, the second sub-region contacts the third thermal conductive sheet, and the third sub-region contacts the fourth thermal conductive sheet. The second sub-region and the third sub-region are arranged in an L-shape around the first sub-region. The first sub-region protrudes a certain distance toward the third sub-plate to adapt to the height of the power switch assembly.

[0011] In the heat dissipation assembly described in this utility model, the first heat-conducting sheet, the third heat-conducting sheet, and the fourth heat-conducting sheet all include aluminum nitride heat-conducting sheets, and the second heat-conducting sheet includes a ceramic heat-conducting sheet.

[0012] In the heat dissipation assembly described in this utility model, the first sub-board, the second sub-board, and the third sub-board are electrically connected by a current-carrying copper busbar.

[0013] The heat dissipation assembly of this utility model installs different heat-generating components on different sub-boards, and then independently mounts the different sub-boards on a liquid cooling plate. The different sub-boards contact the liquid cooling plate through different heat-conducting structures. It can perform different heat dissipation designs for different heat-generating components, thus achieving balanced heat dissipation and avoiding mechanical stress problems caused by temperature differences. Furthermore, since each sub-board is installed independently, it can be disassembled and replaced individually, resulting in low production and maintenance costs. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic diagram of a preferred embodiment of the heat dissipation component of this utility model; Figure 2 This is a schematic diagram of the structure of each sub-board and the heat dissipation component of the present invention; Figure 3 This is a schematic diagram of the liquid cooling plate of the heat dissipation component of this utility model. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] Figure 1 This is a schematic diagram of a preferred embodiment of the heat dissipation component of this utility model. Figure 2 This is a schematic diagram of the structure of each sub-board and the heat-generating component of the heat dissipation component of this utility model. Figure 3 This is a schematic diagram of the liquid cooling plate of the heat dissipation component of this utility model. The following will be combined with... Figures 1-3 The heat dissipation component of this utility model is described below.

[0017] like Figures 1-3 As shown, the heat dissipation assembly includes a printed circuit board and a liquid cooling plate 10. The printed circuit board includes a first sub-board 20, a second sub-board 30, a third sub-board 40, a first heating element 50 mounted on the first sub-board 20, a second heating element 60 mounted on the second sub-board 30, and a third heating element 70 mounted on the third sub-board 40. The first sub-board 20, the second sub-board 30, and the third sub-board 40 are independently mounted on the liquid cooling plate 10. The first sub-board 20, the second sub-board 30, and the third sub-board 40 are electrically connected to each other. The first heating element 50, the second heating element 60, and the third heating element 70 include different heating devices. The first sub-board 20, the second sub-board 30, and the third sub-board 40 are in contact with the liquid cooling plate 10 through different thermally conductive structures. The heat dissipation assembly of this utility model installs different heat-generating components on different sub-boards, and then the different sub-boards are independently mounted on the liquid cooling plate. The different sub-boards contact the liquid cooling plate through different heat-conducting structures. Therefore, different heat dissipation can be carried out for different heat-generating components, thereby achieving balanced heat dissipation and avoiding mechanical stress problems caused by temperature differences. Furthermore, since each sub-board is installed independently, it can be disassembled and replaced individually, resulting in low production and maintenance costs.

[0018] Further as Figures 1-3 As shown, the first sub-plate 20 is fixed to the first region 11 of the liquid-cooled surface of the liquid-cooled plate 10 by a first fixing device; the second sub-plate 30 is fixed to the second region 12 of the liquid-cooled surface of the liquid-cooled plate 10 by a second fixing device; the third sub-plate 40 is fixed to the third region 13 of the liquid-cooled surface of the liquid-cooled plate 10 by a third fixing device; the first region 11, the second region 12 and the third region 13 do not overlap with each other.

[0019] Further as Figures 1-3 As shown, the first sub-board 20 is separated from the first region 11 by a first distance, the second sub-board 30 is separated from the second region 12 by a second distance, and the third sub-board 40 is separated from the third region 13 by a third distance; the first distance matches the height of the first heating component 50; the second distance matches the height of the second heating component 60; and the third distance matches the height of the third heating component 70.

[0020] Further as Figures 1-3As shown, a first heat-conducting structure is provided between the first heating component 50 and the first region 11; a second heat-conducting structure is provided between the second heating component 60 and the second region 12; and a third heat-conducting structure is provided between the third heating component 70 and the third region 13.

[0021] Further as Figures 1-3 As shown, the first heating component 50 includes a filter inductor 51 and a filter peripheral circuit. (As...) Figure 2 As shown, the filter inductor 51 includes two filter inductors, which are disposed at the center of the first sub-board, and the filter peripheral circuit is arranged around the filter inductor. The first thermally conductive structure includes thermal paste coated on the filter inductor 51 and a first thermally conductive sheet disposed on the fuse 52 of the filter peripheral circuit. The first thermally conductive sheet is preferably an aluminum nitride thermally conductive sheet with a thermal conductivity of 4 W / (mK) and a thickness of 5 mm. The first fixing device is a first fixing screw, such as an M4*10 carbon steel zinc-nickel alloy screw, which can be tightened to the first region 11 of the liquid cooling plate 10 with a torque of 5 kgf·cm, providing a large and stable contact pressure. The first region 11 contacts the thermal paste and the first thermally conductive sheet respectively, thereby providing good heat dissipation for the first heat-generating component 50. Preferably, the thermal resistance of the thermal paste is 0.0031℃*in2 / W.

[0022] like Figures 2-3 As shown, the second heat-generating component 60 includes a power inductor 61. Preferably, the power inductor 61 covers the entire second sub-board 30. The second thermally conductive structure includes thermal paste coated on the power inductor 61. The second fixing device is a second fixing screw, such as an M3*8 carbon steel zinc-nickel alloy screw, which can be tightened to the first region 12 of the liquid cooling plate 10 with a torque of 5 kgf·cm, providing a large and stable contact pressure. The second region 12 contacts the thermal paste, thereby providing good heat dissipation for the second heat-generating component 60.

[0023] like Figure 2As shown, the third heating component 70 includes a power switch group 71, a first bus capacitor group 72, a second bus capacitor group 73, and a control circuit. The power switch group 71 includes multiple power switches, which are disposed in the middle of the third sub-board 40. The first bus capacitor group 72 and the second bus capacitor group 73 are arranged in an L-shape around the power switch group 71. The third heat-conducting structure includes a second heat-conducting sheet disposed on the power switch group 71, silicone grease coated on the second heat-conducting sheet, a third heat-conducting sheet disposed on the first bus capacitor group 72, and a fourth heat-conducting sheet disposed on the second bus capacitor group 73. The second heat-conducting sheet is preferably a ceramic heat-conducting sheet with a thermal conductivity of 22 W / (mK). The third and fourth heat-conducting sheets are preferably aluminum nitride heat-conducting sheets with a thermal conductivity of 4 W / (mK) and a thickness of 5 mm. The third fixing device is a third fixing screw, such as an M3*8 carbon steel zinc-nickel alloy screw, which can be tightened into the third region 13 of the liquid cooling plate 10 with a torque of 5 kgf·cm, providing a large and stable contact pressure. Furthermore, each power switch is fixed to the third region 13 by a fourth fixing screw. The fourth fixing screw is preferably an M4*15 carbon steel zinc-nickel alloy Phillips head double-washer combination screw, tightened with a torque wrench in a prescribed diagonal sequence with a torque of 5 kgf·cm, providing a large and stable contact pressure. This ensures uniform contact pressure between the power switch and the liquid cooling plate 10.

[0024] like Figure 3 As shown, the third region 13 includes a first sub-region 131, a second sub-region 132, and a third sub-region 133. The first sub-region 131 contacts the second thermal pad and the silicone grease, the second sub-region 132 contacts the third thermal pad, and the third sub-region 133 contacts the fourth thermal pad. Figure 3 As shown, the second sub-region 132 and the third sub-region 133 are arranged in an L-shape around the first sub-region 131; the first sub-region 131 protrudes towards the third sub-plate 40 by a set distance to accommodate the height of the power switch assembly 71. The liquid cooling plate 10 can be any known liquid cooling plate in the art, and it has internal liquid cooling channels. Figure 3 As shown, the first sub-region 131 is a first rectangular region, and the second sub-region 132 consists of a second rectangular region and a third rectangular region located on two adjacent sides of the first sub-region 131; the first rectangular region protrudes a certain distance towards the third sub-plate 40. Further as... Figure 2 As shown, the first sub-board 20, the second sub-board 30 and the third sub-board 40 are electrically connected by a current-carrying copper busbar 80.

[0025] The following will combine Figures 1-3The design principle of the heat dissipation component of this utility model is explained as follows.

[0026] Thermal analysis shows that inductors and power switches are the main heat sources on the printed circuit board, accounting for more than 85% of the total heat loss. Therefore, we divide the printed circuit board into a first sub-board 20, a second sub-board 30, and a third sub-board 40. The first sub-board 20 is a smaller sub-board, on which the first heat-generating component 50 (i.e., the filter inductor 51 and the filter peripheral circuit) is installed; the second sub-board 30 is also a smaller sub-board, on which the second heat-generating component 60 (i.e., all the power inductors 61) is installed. This sub-board is the source of heat loss and electromagnetic interference. The third sub-board 40 is slightly larger, on which the third heat-generating component 70 (power switch group 71, first bus capacitor group 72, second bus capacitor group 73, and control circuit) is installed. The power switch is the main source of electromagnetic interference, and the controller and its peripheral circuit are sensitive to noise. The power switch and control circuit are further divided in layout.

[0027] Each sub-board can be partitioned according to its function, noise level, heat dissipation density, and heat dissipation requirements. Separation of "Power" and "Control": This is the core partitioning principle. Power circuits (first and second sub-boards 20 and 30) that generate drastic voltage changes (high dv / dt) and current changes (high di / dt) are isolated from control circuits (sub-board 40) that handle sensitive small signals, eliminating interference from power stage noise to the control stage. Separation of "Switching Devices" and "Capacitors": Separating the heat dissipation of the power switch group 71 from the second bus capacitor group 73 allows for optimized layout and heat dissipation strategies for each component.

[0028] For the third daughterboard 40, the power switch group 71 is the primary heat source. Therefore, this daughterboard uses a ceramic substrate (such as DBC / AMB) instead of the traditional FR-4 to achieve extremely low thermal resistance and excellent insulation withstand voltage. Its thermal pads are made of ceramic sheets and use the thinnest feasible thickness, only 1.0 mm, to minimize the thermal resistance between the chip junction and the liquid cooler. Its thermal structure uses high-performance thermal paste (50a) to ensure optimal heat conduction. High-strength M4*15 carbon steel zinc-nickel alloy Phillips head double-waist combination screws provide uniform and high locking pressure (e.g., >5 kgf·cm) to overcome stress and material creep caused by thermal cycling and maintain long-term stable contact thermal resistance. Since the first bus capacitor group 72 itself has losses and is close to the heat source, it requires heat dissipation, but its need is less than that of the power switch group 71. Its core is to construct a low parasitic inductance loop, using aluminum nitride thermal pads and M3*8 carbon steel zinc-nickel alloy screws for fixation. For the second daughterboard 30, thermally conductive potting compound is used for heat dissipation, and thermal paste is used on the bottom.

[0029] Because the power switch assembly 71 and the large capacitor are heavy and expand significantly during thermal cycling, separating them onto different smaller boards greatly reduces the deformation of each board, avoiding the risk of warping and solder joint cracking caused by stress concentration on a single large board. Each sub-board can independently adapt to thermal expansion without pulling on each other.

[0030] This utility model also provides an assembly method for the aforementioned heat dissipation component, including a thermal analysis and layout stage: performing thermal simulation analysis on the circuit to identify hot spots and high heat dissipation devices; planning the board boundaries based on heat dissipation and device dimensions; manufacturing the first sub-board, the second sub-board, and the third sub-board separately; independently mounting the first sub-board, the second sub-board, and the third sub-board onto the liquid cooling plate using their respective optimized fixing methods and heat dissipation structures; and electrically connecting each sub-board via current-carrying copper busbars.

[0031] Compared with existing technologies, this invention has the following significant advantages: 1. Improved heat dissipation efficiency: Precise heat dissipation is achieved for devices with different heat dissipation levels, and optimal heat dissipation resources (such as superior thermal grease materials, greater pressure, and thermally conductive sheets with higher thermal conductivity) are applied to high-heat areas, completely eliminating overheating bottlenecks and reducing the junction temperature of key components by 10℃-20℃. 2. Reduced mechanical stress and warpage risk: By breaking down large boards into smaller units, thermal stress on individual boards is significantly reduced, improving the reliability and lifespan of the entire module under thermal cycling. 3. Optimized cost and weight: Expensive thermally conductive materials and complex fastening structures are used only where necessary, while standard solutions are used in low-heat-dissipation areas, resulting in an overall reduction in material costs and module weight. 4. Facilitated maintenance and upgrades: If a sub-board (such as a power sub-board) is damaged or needs upgrading, the sub-board can be replaced individually without dealing with the entire component, reducing maintenance costs and time.

[0032] Although this utility model has been described through specific embodiments, those skilled in the art should understand that various modifications and equivalent substitutions can be made to this utility model without departing from its scope. Furthermore, various modifications can be made to this utility model for specific situations or materials without departing from its scope. Therefore, this utility model is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims of this utility model.

[0033] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat dissipation assembly, the heat dissipation assembly comprising a printed circuit board and a liquid cooling plate, characterized in that, The printed circuit board includes a first sub-board, a second sub-board, a third sub-board, a first heating component mounted on the first sub-board, a second heating component mounted on the second sub-board, and a third heating component mounted on the third sub-board. The first sub-board, the second sub-board, and the third sub-board are independently mounted on the liquid cooling plate; the first sub-board, the second sub-board, and the third sub-board are electrically connected to each other; The first heating component, the second heating component, and the third heating component each include different heating devices; the first sub-board, the second sub-board, and the third sub-board are in contact with the liquid cooling plate through different thermally conductive structures.

2. The heat dissipation assembly according to claim 1, characterized in that, The first sub-plate is fixed to a first region of the liquid-cooled surface of the liquid-cooled plate by a first fixing device; the second sub-plate is fixed to a second region of the liquid-cooled surface of the liquid-cooled plate by a second fixing device; the third sub-plate is fixed to a third region of the liquid-cooled surface of the liquid-cooled plate by a third fixing device; the first region, the second region and the third region do not overlap with each other.

3. The heat dissipation assembly according to claim 2, characterized in that, The first sub-board is separated from the first region by a first distance, the second sub-board is separated from the second region by a second distance, and the third sub-board is separated from the third region by a third distance; The first distance matches the height of the first heating element; the second distance matches the height of the second heating element; and the third distance matches the height of the third heating element.

4. The heat dissipation assembly according to claim 3, characterized in that, A first heat-conducting structure is provided between the first heating component and the first region; a second heat-conducting structure is provided between the second heating component and the second region; and a third heat-conducting structure is provided between the third heating component and the third region.

5. The heat dissipation assembly according to claim 4, characterized in that, The first heating component includes a filter inductor and a filter peripheral circuit; The first thermally conductive structure includes a first thermally conductive paste coated on the filter inductor and a first thermally conductive sheet disposed on the fuse of the filter peripheral circuit; The first fixing device is a first fixing screw; The first area is in contact with the first thermal paste and the first thermal sheet, respectively.

6. The heat dissipation assembly according to claim 5, characterized in that, The second heat-generating component includes a power inductor; The second thermally conductive structure includes a second thermally conductive paste coated on the power inductor; The second fixing device is the second fixing screw; The second area comes into contact with the second thermal paste.

7. The heat dissipation assembly according to claim 6, characterized in that, The third heating component includes a power switch group, a first bus capacitor group, a second bus capacitor group, and a control circuit. The power switch group is located in the middle of the third sub-board and includes multiple power switches. The first bus capacitor group and the second bus capacitor group are arranged in an L-shape around the power switch group. The third thermal conductive structure includes a second thermal conductive sheet disposed on the power switch assembly, silicone grease coated on the second thermal conductive sheet, a third thermal conductive sheet disposed on the first bus capacitor assembly, and a fourth thermal conductive sheet disposed on the second bus capacitor assembly. The third fixing device includes a third fixing screw; Each of the power switches is fixed to the third region by a fourth fixing screw.

8. The heat dissipation assembly according to claim 7, characterized in that, The third region includes a first sub-region, a second sub-region, and a third sub-region. The first sub-region contacts the second thermal pad and the silicone grease. The second sub-region contacts the third thermal pad. The third sub-region contacts the fourth thermal pad. The second and third sub-regions are arranged in an L-shape around the first sub-region. The first sub-region protrudes a certain distance toward the third sub-plate to accommodate the height of the power switch assembly.

9. The heat dissipation assembly according to claim 8, characterized in that, The first, third, and fourth thermal conductive sheets are aluminum nitride thermal conductive sheets, and the second thermal conductive sheet is a ceramic thermal conductive sheet.

10. The heat dissipation assembly according to any one of claims 5 to 9, characterized in that, The first sub-board, the second sub-board, and the third sub-board are electrically connected via a current-carrying copper busbar.

Images