A double-sided water-cooled heat-dissipation OBC power module shell structure

Abstract

The utility model discloses a double -faced water -cooling heat dissipation's OBC power module casing structure, through the top cap is integrated into the heat dissipation component with the initiative water cooling function, has provided efficient heat dissipation path for the core power chip of PCB top surface, thereby significantly reduced chip work junction temperature, ensure that it long -term work is in the safe temperature interval, has greatly promoted the operation reliability and service life of OBC power module, has broken the heat dissipation bottleneck, makes it possible to adopt higher performance power chip or promote its work load, has supported the development of OBC power module to higher power density, smaller volume and lighter weight direction, through cooperation with water cooling board builds the double -faced symmetry water -cooling heat dissipation frame for the both sides of PCB, makes the temperature field distribution of both sides of PCB more uniform, effectively alleviated the thermal stress problem caused by the temperature difference too big, further enhanced the mechanical reliability and long -term work stability of OBC power module.

Description

Technical Field

[0001] This utility model belongs to the field of power module technology and relates to a power heat dissipation structure, specifically a double-sided water-cooled OBC power module housing structure. Background Technology

[0002] With the rapid development of new energy vehicles, on-board chargers (OBCs), as core components, are constantly evolving towards higher power density, smaller size, and higher efficiency. High power density means a significant increase in heat dissipation per unit volume, which poses an extremely severe challenge to the heat dissipation design of OBC modules.

[0003] Currently, mainstream OBC power modules generally adopt a double-sided layout of components on printed circuit boards (PCBs) to optimize space. The core power chips that generate significant heat (such as the main control IC and power switching transistors) are typically located on the top layer of the PCB. The corresponding heat dissipation solutions are usually as follows: for the bottom layer of the PCB, the bottom layer is in close contact with a water-cooling plate, utilizing coolant circulation to actively remove heat from the bottom components and some of the heat conducted through the PCB; for the top layer of the PCB, the main heat-generating components are in contact with the inner surface of the metal top cover via thermally conductive silicone pads, conducting heat to the metal top cover, and then relying on natural convection and thermal radiation between the top cover and the high-temperature air inside the module housing for heat dissipation.

[0004] However, the aforementioned existing technical solutions have the following significant drawbacks and limitations: The severely uneven heat dissipation efficiency leads to excessively high chip junction temperatures: the main heat source is concentrated on the top layer of the PCB, but its heat dissipation path is long and has high thermal resistance. Heat must pass through the contact thermal resistance of the thermally conductive silicone pad, the conduction thermal resistance of the top cover itself, and the convective heat transfer thermal resistance at the interface between the top cover and the high-temperature air, resulting in poor overall heat dissipation efficiency. In contrast, the active heat dissipation path on the bottom layer of the PCB, achieved through a water-cooled plate, has extremely low thermal resistance. This severe imbalance in heat dissipation capabilities between the top and bottom layers prevents the heat generated by the core power chip on the top layer from being effectively dissipated in a timely manner, causing its junction temperature to remain high and becoming the thermal bottleneck of the system. Passive heat dissipation is ineffective in high-temperature environments: When the OBC power module is running, the internal ambient temperature of its casing can typically reach 85°C or even higher. Under such high temperatures, the heat dissipation of the top layer of the PCB board, which relies on the natural convection and radiation of the top cover with the air, is extremely limited due to the very small temperature difference (ΔT), and can hardly provide effective cooling for the high-power core chip.

[0005] Severely impacting system reliability and lifespan: The lifespan of electronic components is inversely related to their operating temperature. Prolonged operation of core power chips at high temperatures significantly accelerates their electrical performance degradation, increases power consumption, creates a vicious cycle of thermal degradation, and may even ultimately lead to thermal failure. This severely reduces the overall reliability of the OBC power module and the vehicle's lifespan.

[0006] Limitations on further increases in power density: Due to the aforementioned heat dissipation bottlenecks, in order to keep the junction temperature of the core power chip within a safe range, it is often necessary to derate the core power chip during product design, or to select a larger size, lower power consumption chip. This directly hinders the further development of OBC power modules towards higher power density and smaller size. Utility Model Content

[0007] To address the technical problems existing in the background art, this utility model proposes a double-sided water-cooled OBC power module housing structure, which achieves efficient and balanced heat dissipation for components on both sides of the PCB board, thereby significantly reducing the junction temperature of the core power chip and improving the power density, reliability and service life of the OBC power module.

[0008] The objective of this utility model can be achieved through the following technical solutions: A double-sided water-cooled OBC power module housing structure includes: a PCB board, a water-cooling plate, a bottom shell, and a top cover. The OBC power module is integrated on the PCB board, and the bottom surface of the PCB board is in close contact with the water-cooling plate to cool the portion of the OBC power module arranged on the bottom surface of the PCB board. Both the PCB board and the water-cooling plate are installed inside the bottom shell, and the top cover is sealed to the bottom shell so that the top surface of the PCB board is in thermal contact with the inner surface of the top cover. Cooling channels are provided inside the top cover to cool the portion of the OBC power module arranged on the top surface of the PCB board.

[0009] Furthermore, the cooling channel adopts a serpentine, parallel, or jet-like coolant circulation channel set in a preset area inside the top cover, with the preset area corresponding to the area directly above part of the OBC power module area on the top surface of the PCB board.

[0010] Furthermore, the cooling channels are machined onto the top cover by casting, milling, brazing, or 3D printing, and the machined cooling channels are sealed by a cover plate welded to the top cover.

[0011] Furthermore, the top cover is provided with a coolant inlet and a coolant outlet, which are respectively connected to the two ends of the cooling channel to circulate coolant into the cooling channel.

[0012] Furthermore, sealing grooves are provided on the end faces of both the coolant inlet and the coolant outlet, and O-ring rubber seals are embedded in the sealing grooves.

[0013] Furthermore, both the coolant inlet and coolant outlet are located on the inner surface of the top cover. The coolant inlet is connected to the water-cooling plate via an inlet pipe, and the coolant outlet is connected to the water-cooling plate via an outlet pipe.

[0014] Furthermore, thermal grease or thermal pads are applied to some of the OBC power modules on the top surface of the PCB board to achieve thermal contact with the inner surface of the top cover.

[0015] Furthermore, the top cover is fitted onto the bottom shell, and the top cover and the bottom shell are locked together by fasteners to ensure that the thermal pad is in close contact with the top surface of the PCB board and the inner surface of the top cover.

[0016] Furthermore, an annular sealing groove is provided on the end face where the top cover connects to the bottom shell, or on the end face where the bottom shell connects to the top cover, and an annular sealing gasket is installed in the sealing groove.

[0017] The beneficial effects of this utility model are as follows: The OBC power module housing structure with double-sided water cooling provided in this application integrates a heat dissipation component with active water cooling function inside the top cover, providing an efficient heat dissipation path for the core power chip on the top surface of the PCB board. This significantly reduces the chip's junction temperature, ensuring that it operates within a safe temperature range for a long time, greatly improving the operational reliability and service life of the OBC power module. It breaks through the heat dissipation bottleneck, making it possible to use higher-performance power chips or increase their workload. This strongly supports the development of OBC power modules towards higher power density, smaller size, and lighter weight. By cooperating with the water cooling plate, a double-sided symmetrical water cooling architecture is constructed for both sides of the PCB board, making the temperature field distribution on both sides of the PCB board more uniform. This effectively alleviates the thermal stress problem caused by excessive temperature difference, further enhancing the mechanical reliability and long-term operational stability of the OBC power module. Attached Figure Description

[0018] Figure 1 This is a three-dimensional schematic diagram of the present invention.

[0019] Figure 2 This is an exploded view of the present invention.

[0020] Figure 3 This is a schematic diagram of the cooling channel of this utility model.

[0021] Figure 4 This is a schematic diagram of the top cover of this utility model.

[0022] Figure 5 This is a schematic diagram of the bottom shell of this utility model. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0024] like Figure 1-2 As shown, this utility model provides a double-sided water-cooled OBC power module housing structure, including: a PCB board 1, a water-cooling plate 2, a bottom shell 3, and a top cover 4. The OBC power module is integrated on both the top and bottom surfaces of the PCB board 1. The water-cooling plate 2 is mounted on the bottom surface of the PCB board 1 so that the circuit components of the OBC power module arranged on the bottom surface of the PCB board 1 are in close contact with the water-cooling plate 2, and the circulating coolant in the water-cooling plate 2 dissipates heat and cools the circuit components of the OBC power module. Both the PCB board 1 and the water-cooling plate 2 are mounted inside the bottom shell 3, and the top cover 4 is sealed to the bottom shell 3 so that the core power chip of the OBC power module arranged on the top surface of the PCB board 1 is in thermal contact with the inner surface of the top cover 4, and the heat generated by the core power chip of the OBC power module can be transferred to the top cover 4. Figure 3 As shown, the top cover 4 has a cooling channel 41 inside, which circulates coolant to cool the core power chip of the OBC power module. This transforms the top cover 4 from a simple protective and passive heat dissipation component into a heat dissipation component with active water cooling function, providing an efficient heat dissipation path for the core power chip of the OBC power module. The thermal resistance is significantly reduced, and actual measurements show that the junction temperature of the core power chip can be reduced by 20℃-40℃, making it far below the safe operating temperature threshold. Together with the water cooling plate 2, it forms a symmetrical and efficient heat dissipation architecture of "double-sided water cooling", which makes the temperature field on both sides of the PCB board 1 more uniform, reduces the internal stress caused by uneven thermal expansion, and further improves the mechanical reliability and long-term stability of the product.

[0025] The cooling channel 41 employs a serpentine, parallel, or jet-like coolant circulation channel set within a pre-defined area inside the top cover 4. This pre-defined area corresponds directly above the core power chip area of ​​the OBC power module on the top surface of the PCB board 1, maximizing heat exchange efficiency and directly removing the enormous heat generated by the core power chip, achieving "precise" and "direct" cooling of the heat source. The cooling channel 41 is machined onto the top cover 4 using methods such as casting, milling, brazing, or 3D printing. The machined cooling channel 41 is then sealed by a cover plate 42 welded to the top cover 4. The top cover 4 and the cover plate 42 are welded together using friction stir welding to ensure the airtightness of the cooling channel 41. This application achieves water channel integration by fully utilizing the existing space of the top cover 4, resulting in a compact structure and reliable assembly without requiring additional volume, thus achieving efficient system-level integration.

[0026] like Figure 4 As shown, the top cover 4 has a coolant inlet 43 and a coolant outlet 44, which are respectively connected to the two ends of the cooling channel 41 to circulate coolant into the cooling channel 41. The coolant flows within the cooling channel 41, directly carrying away the heat conducted from the inner surface of the top cover 4. Both the coolant inlet 43 and the coolant outlet 44 are located on the inner surface of the top cover 4. Figure 5 As shown, the coolant inlet 43 is connected to the water-cooled plate 2 via the inlet pipe 21, and the coolant outlet 44 is connected to the water-cooled plate 2 via the outlet pipe 22. During operation, the coolant supplied by the external cooling system enters from the water-cooled plate 2, flows from the coolant inlet 43 through the inlet pipe 21 into the cooling channel 41 of the top cover 4, and after heat exchange in the cooling channel 41, the coolant returns to the water-cooled plate 2 from the coolant outlet 44 through the outlet pipe 22, and is then output from the water-cooled plate 2 to the external cooling system for circulation. This efficiently integrates two independent water-cooling structures (water-cooled plate 2 and cooling channel 41) into a compact OBC power module housing, maximizing heat dissipation efficiency. Sealing grooves are provided on the end faces of both the coolant inlet 43 and the coolant outlet 44, and O-ring rubber seals 5 are embedded in these grooves. When the inlet pipe 21 / outlet pipe 22 is connected to the coolant inlet 43 / coolant outlet 44 and tightened, the rubber seals 5 are compressed, achieving a reliable static seal and preventing coolant leakage.

[0027] The core power chip of the OBC power module on the top surface of PCB board 1 can achieve thermal contact with the inner surface of the top cover 4 by applying thermal grease or covering it with thermal pad 6. The top cover 4 is fitted onto the bottom shell 3, and the top cover 4 and the bottom shell 3 are locked together by fasteners 7 to ensure that the thermal pad 6 is in close contact with both the top surface of PCB board 1 and the inner surface of the top cover 4, further reducing contact thermal resistance. The fasteners 7 are bolts evenly distributed around the shell structure to apply a uniform locking force to firmly fix the top cover 4 and the bottom shell 3. An annular sealing groove is formed on the end face where the top cover 4 and the bottom shell 3 connect, or on the end face where the bottom shell 3 and the top cover 4 connect. An annular sealing gasket 8 is installed in the sealing groove to achieve a sealed connection between the top cover 4 and the bottom shell 3, forming a sealed cavity to seal the internal electrical environment of the OBC power module.

[0028] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.

Claims

1. A double-sided water-cooled OBC power module housing structure, characterized in that, include: The PCB board (1), water-cooled plate (2), bottom shell (3), and top cover (4) are integrated on the PCB board (1). The bottom surface of the PCB board (1) is in close contact with the water-cooled plate (2) so that the water-cooled plate (2) can dissipate heat and cool the part of the OBC power module arranged on the bottom surface of the PCB board (1). The PCB board (1) and the water-cooled plate (2) are both installed in the bottom shell (3). The top cover (4) is sealed and connected to the bottom shell (3) so that the top surface of the PCB board (1) is in thermal contact with the inner surface of the top cover (4). The top cover (4) is provided with a cooling channel (41) to dissipate heat and cool the part of the OBC power module arranged on the top surface of the PCB board (1).

2. The shell structure according to claim 1, characterized in that, The cooling channel (41) adopts a serpentine, parallel or jet-like coolant circulation channel set in a preset area inside the top cover (4). The preset area is set directly above part of the OBC power module area on the top surface of the PCB board (1).

3. The shell structure according to claim 2, characterized in that, The cooling channels (41) are machined on the top cover (4) by casting, milling, brazing or 3D printing. The machined cooling channels (41) are sealed by the cover plate (42) welded to the top cover (4).

4. The shell structure according to claim 1, characterized in that, The top cover (4) has a coolant inlet (43) and a coolant outlet (44). The coolant inlet (43) and the coolant outlet (44) are respectively connected to the two ends of the cooling channel (41) to circulate coolant into the cooling channel (41).

5. The shell structure according to claim 4, characterized in that, A sealing groove is provided on the end face of both the coolant inlet (43) and the coolant outlet (44), and an O-ring rubber sealing ring (5) is embedded in the sealing groove.

6. The shell structure according to claim 4, characterized in that, The coolant inlet (43) and coolant outlet (44) are both located on the inner surface of the top cover (4). The coolant inlet (43) is connected to the water cooling plate (2) through the inlet pipe (21), and the coolant outlet (44) is connected to the water cooling plate (2) through the outlet pipe.

7. The shell structure according to claim 1, characterized in that, The top surface of the PCB board (1) is partially covered with thermal grease or thermal pad (6) to achieve thermal contact with the inner surface of the top cover (4).

8. The shell structure according to claim 7, characterized in that, The top cover (4) is placed on the bottom shell (3), and the top cover (4) and the bottom shell (3) are locked together by fasteners (7) so that the heat-conducting pad (6) is in close contact with the top surface of the PCB board (1) and the inner surface of the top cover (4).

9. The shell structure according to claim 8, characterized in that, On the end face where the top cover (4) connects to the bottom shell (3), or on the end face where the bottom shell (3) connects to the top cover (4), an annular sealing groove is provided, and an annular sealing gasket (8) is installed in the sealing groove.

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