Heat dissipation structure and on-board charger

Abstract

The present invention provides a heat dissipation structure and an on-board charger, comprising a base, a heat dissipation channel extending upward from the base, a PCB board located above a substrate and electrically connected to a power device, and a substrate with at least one power device mounted on the side of the heat dissipation channel. The heat dissipation channel of the heat dissipation structure and the on-board charger provided by the present invention adopts a three-dimensional design perpendicular to the substrate and parallel to the PCB board, effectively improving the plane and spatial utilization of the channel. Combined with the thermal conductivity and compact size of the metal substrate, this ensures signal transmission and overall power density while improving the heat dissipation efficiency of the power device and overall space utilization, thus facilitating the integration, miniaturization, and lightweighting of the on-board charger. The power device is replaced by a surface-mounted chip, resulting in better consistency. Pins are directly provided on the top surface of the metal substrate to achieve power transmission, saving area and maximizing the effective heat dissipation area of ​​the metal substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of power device heat dissipation, and more particularly to a water-cooled heat dissipation structure and an on-board charger. Background Art

[0002] With the advancement of electronic technology, electronic devices have become increasingly widely used. Simultaneously, their power density continues to increase, leading to a corresponding increase in heat generation. Therefore, heat dissipation has become a major bottleneck hindering the further development of electronic technology. Extensive experience has demonstrated that temperature is a primary cause of electronic device failure, and the probability of device failure increases exponentially with increasing temperature. Electronic devices are required to operate at near-full load for extended periods of time, making heat dissipation a significant challenge under limited conditions. In applications such as electric vehicles, motor controllers and onboard chargers experience high ambient temperatures. These components, which include functional components such as IGBTs, MOSFETs, and capacitors, are extremely sensitive to temperature. High temperatures can negatively impact component performance, at best, and even lead to explosions and other accidents.

[0003] At present, most of the high-power conversion devices used in the power transmission system of on-board chargers are plug-in type. The power devices are directly attached to the metal substrate (aluminum substrate or copper substrate), and then the metal substrate is fixed on the flat (parallel to the horizontal plane) waterway. Figure 1 , a traditional planar water channel is used to dissipate heat for power devices. The metal substrate, water channel, and water channel cover 6 are all arranged parallel to the horizontal plane, resulting in low plane and space utilization of the water channel heat dissipation structure. At the same time, the numerous power transfer interfaces on the traditional metal substrate occupy a large area of ​​the metal substrate, and the effective area and utilization rate of the metal substrate for heat dissipation are low.

[0004] Therefore, the heat dissipation structure of the power device and the on-board charger of the traditional planar water channel have low overall space utilization, which is not conducive to the improvement of power density and the requirements of product integration and miniaturization, which is a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0005] In order to solve the technical problem that the existing planar water channel heat dissipation structure of power devices and on-board chargers have low overall space utilization, which is not conducive to improving power density and meeting the requirements of product integration and miniaturization, the present invention proposes a water-cooled heat dissipation structure and on-board charger suitable for power devices with high space utilization and power density.

[0006] To solve the problem, the technical solution adopted by the present invention is: providing a heat dissipation structure, including a base, a heat dissipation water channel provided on the base, a PCB board located above the heat dissipation water channel and electrically connected to the power device, and also including: a substrate located on the side of the heat dissipation water channel and using the heat dissipation water channel for heat dissipation, and the power device is mounted on the substrate.

[0007] Furthermore, the substrate is parallel to the side of the heat dissipation channel, and the substrate and the PCB are perpendicular to each other.

[0008] Furthermore, the heat dissipation water channel includes a water channel body, a water inlet and a water outlet arranged on the water channel body, a water channel cavity arranged in the water channel body and used to accommodate coolant, and the water channel cavity connects the water inlet and the water outlet.

[0009] Preferably, one side of the water channel body is provided with an opening communicating with the inner cavity of the water channel, the base plate covers the opening and the inner cavity of the water channel is sealed by a sealing ring.

[0010] Preferably, at least one side surface of the water channel body is a mounting surface, the heat dissipation surface of the substrate is mounted in contact with the mounting surface, and a heat conductive layer is filled between the heat dissipation surface and the mounting surface.

[0011] Furthermore, the top of the substrate is provided with at least one plug port electrically connected to the power device, the PCB board is provided with a slot allowing the plug port to be inserted, and a conductor for electrically connecting to the plug port is arranged in the slot.

[0012] Furthermore, the substrate is pressed against the side surface of the heat dissipation channel by a pressing piece, and the pressing piece is provided with a notch corresponding to the position of the power device.

[0013] Furthermore, the base is provided with at least one pillar, and the substrate is provided with a supporting copper bar corresponding to the pillar and extending toward the pillar. One end of the supporting copper bar is clamped and installed between the top of the pillar and the PCB board, and the other end of the supporting copper bar is connected to the substrate.

[0014] Furthermore, the substrate is a metal substrate, the side of the substrate away from the heat dissipation channel is the working surface, and the side close to the heat dissipation channel is the heat dissipation surface. The working surface is provided with power devices and control circuits electrically connected to the power devices, and the heat dissipation surface is installed on the side of the heat dissipation channel.

[0015] The present invention also provides a vehicle-mounted charger, comprising the above-mentioned heat dissipation structure.

[0016] Compared with the prior art, the heat dissipation structure and vehicle charger provided by the present invention have the following beneficial effects:

[0017] The heat dissipation structure and on-board charger provided by the present invention feature a three-dimensional design in which the heat dissipation water channel is perpendicular to the substrate and parallel to the PCB board, effectively improving the plane and space utilization of the water channel. Combined with the strong thermal conductivity and compact board volume of the metal substrate, this ensures signal transmission and overall power density while improving the heat dissipation efficiency of the power device and the overall space utilization, which is conducive to the overall integration, miniaturization, and lightweighting of the on-board charger. The power device is replaced by a surface-mounted form factor, which improves the consistency of the power device. Pins are directly provided on the top surface of the metal substrate to achieve power transmission, saving the area of ​​the metal substrate's working surface and maximizing the utilization of the metal substrate's effective heat dissipation area. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the existing heat dissipation structure;

[0019] Figure 2 A schematic diagram of an exploded structure of an embodiment of the heat dissipation structure provided by the present invention;

[0020] Figure 3 A schematic diagram of the connection between a substrate and a PCB board of an embodiment of the heat dissipation structure provided by the present invention;

[0021] Figure 4 A schematic diagram of the overall structure of an embodiment of the heat dissipation structure provided by the present invention;

[0022] Figure 5 A schematic diagram of an exploded structure of an embodiment of the heat dissipation structure provided by the present invention;

[0023] Figure 6 A schematic diagram of the connection between a substrate and a PCB board of an embodiment of the heat dissipation structure provided by the present invention;

[0024] Figure 7 A schematic diagram of the overall structure of an embodiment of the heat dissipation structure provided by the present invention;

[0025] Figure 8 This is a schematic diagram of the exploded structure of another embodiment of the heat dissipation structure provided by the present invention.

[0026] Among them, the main marks of the drawings in the figure are:

[0027] 1-PCB board; 11-first slot; 12-second slot; 13-drilling; 2-substrate; 21-power device; 22-control circuit; 23-pin; 231-soldering pad; 24-signal terminal; 25-support copper busbar; 26-power copper busbar; 3-heat dissipation water channel; 31-pillar; 32-water channel cavity; 33-sealing ring; 34-base; 4-pressing piece; 41-notch; 5-screw; 6-water channel cover. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear, the following is a summary of the technical problems, technical solutions and beneficial effects to be solved by the present invention. Figure 2-8 The present invention is further described in detail with reference to the accompanying drawings and embodiments.

[0029] The present invention provides a heat dissipation structure, including a base 34, which is preferably a plate-shaped member and is connected to the bottom plate of the vehicle charger housing during assembly; a heat dissipation water channel 3 provided on the base 34, which extends upward from the base 34 and is made of a heat-conducting material, including: a water channel body, which is provided on the base 34 and is preferably formed integrally with the base 34; a water inlet and a water outlet (not shown in the figure) provided on the water channel body, and a water channel cavity 32 provided in the water channel body and connected to the water inlet and the water outlet for accommodating coolant.

[0030] A PCB 1 is positioned above the heat dissipation channel 3 and electrically connected to the power device 21. A substrate 2 is positioned to the side of the heat dissipation channel 3 and utilizes the heat dissipation channel 3 for heat dissipation. This substrate 2 is provided with at least one power device 21. This substrate 2 is preferably a metal substrate 2, such as an aluminum substrate 2 or a copper substrate 2. The power device 21 is preferably a power transistor. In one embodiment, the heat dissipation channel 3 has a rectangular shape perpendicular to the base 34. The substrate 2 is perpendicular to the base 34 and parallel to the sides of the heat dissipation channel. The PCB 1 is parallel to the base 34, meaning that the substrate 2 is parallel to the heat dissipation channel 3 and perpendicular to the PCB 1.

[0031] At least one side of the heat dissipation channel 3's water channel body serves as a mounting surface, and the heat dissipation surface of the substrate 2 is mounted in contact with the mounting surface. In one embodiment, a thermally conductive layer is filled between the heat dissipation channel 3 and the substrate 2. This thermally conductive layer is preferably made of thermally conductive silicone grease, which fills the gap between the mounting surface of the heat dissipation channel 3 and the heat dissipation surface of the substrate 2, thereby increasing the contact area between the mounting surface and the heat dissipation surface. The thermally conductive layer of thermally conductive silicone grease between the heat dissipation channel 3 and the substrate 2 enhances the thermal conductivity between the heat dissipation channel 3 and the substrate 2, thereby improving the heat dissipation efficiency of the heat dissipation channel 3 to the substrate 2. In a preferred embodiment, both sides of the heat dissipation channel 3's water channel body serve as mounting surfaces, and substrates 2 are mounted on bases 34 on both sides of the heat dissipation channel 3. This multiplies the area of ​​the substrate 2 and the number of power devices 21 while slightly increasing the structural volume, thereby improving the heat dissipation efficiency of the heat dissipation channel 3 to the power devices 21, space utilization, and overall power density.

[0032] As an embodiment, the substrate 2 is pressed against the heat dissipation channel 3 by a pressing member 4. The pressing member 4 is preferably an L-shaped plate composed of a continuous bottom plate and side plates. The bottom plate is fixed to the base 34 by screws 5. The side plates press the substrate 2 toward the heat dissipation channel 3 and clamp the heat dissipation channel 3 between the substrate 2. As a preferred embodiment, components such as the power device 21 are disposed on the side of the substrate 2 opposite the heat dissipation surface. The side plates of the pressing member 4 are provided with notches 41 corresponding to the power devices 21 to enhance the heat dissipation capacity of the power devices 21. The notches 41 limit the displacement of the power devices 21 and the substrate 2 in a direction parallel to the heat dissipation channel 3, thereby positioning the substrate 2.

[0033] As an embodiment, the base 34 is provided with at least one pillar 31, and the base plate 2 is provided with a supporting copper bar 25 corresponding to the pillar 31 and extending toward the pillar 31. One end of the supporting copper bar 25 is clamped and installed between the top of the pillar 31 and the PCB 1, and the other end of the supporting copper bar 25 is connected to the base plate 2. As an implementation method, the top of one end of the supporting copper bar 25 is connected to the PCB 1, the bottom of one end of the supporting copper bar 25 is connected to the top of the pillar 31, and the other end of the supporting copper bar 25 is connected to the base plate 2. The screw 5 passes through the corresponding mounting holes of the PCB 1 and the supporting copper bar 25 and is screwed into the threaded hole at the top of the pillar 31. The supporting copper bar 25 and the pillar 31 support the PCB 1.

[0034] The top of the substrate 2 is provided with at least one plug-in port electrically connected to the power device 21, and the PCB board 1 is provided with a slot allowing the plug-in port to be inserted. A conductor for electrically connecting to the plug-in port is arranged in the slot. The conductor is preferably a metal part made of metal such as copper and aluminum, and is soldered in the slot by reflow soldering.

[0035] In one embodiment, the plug-in port is a pin 23 located on the top surface of the substrate 2 and extending upward. The pin 23 is preferably integrally formed with the substrate 2. The PCB 1 is provided with a first slot 11 corresponding to the power connection of the pin 23. A solder pad 231 is provided on one sidewall of the pin 23, and a conductor corresponding to the solder pad 231 is provided on one sidewall of the first slot 11. By directly providing the pin 23 on the top surface of the metal substrate 2 to achieve power transmission, the area occupied by the pin 23 on the metal substrate 2 is reduced, thereby maximizing the effective heat dissipation area of ​​the metal substrate 2.

[0036] As an embodiment, the plug-in port is at least one power copper bus 26 provided on the top of the substrate 2. The power copper bus 26 is preferably soldered to the top of the side of the substrate 2 away from the heat dissipation channel 3 by reflow soldering; the PCB board 1 is provided with a second slot 12 for power connection to the power copper bus 26. The four side walls of the second slot 12 are all made of conductors and are power-connected to the four side walls of the port of the power copper bus 26 in a one-to-one correspondence.

[0037] As an embodiment, a power device 21 and a control circuit 22 electrically connected to the power device 21 are provided on a side of the substrate 2 away from the heat dissipation water channel 3, and the power device 21 is soldered on the substrate 2; at least one signal terminal 24 electrically connected to the control circuit 22 and to the PCB board 1 is provided on the top of the substrate 2, and the signal terminal 24 is preferably soldered to the top of the side of the substrate 2 away from the heat dissipation water channel 3 by reflow soldering; the PCB board 1 is provided with a drill hole 13 connected to the signal terminal 24, and the side wall of the drill hole 13 is provided with a conductor corresponding to the signal terminal 24.

[0038] In one embodiment, the substrate 2 is a metal substrate 2 with excellent thermal conductivity and a compact footprint. This allows for rapid heat transfer from the power devices 21 to the cooling channels 3, improving the space utilization and overall power density of the cooling channels 3. The side of the substrate 2 facing away from the cooling channels 3 is the working surface, while the side facing the cooling channels 3 is the heat dissipation surface. The working surface is equipped with the power devices 21, power copper busbars 26, and control circuitry 22 electrically connected to the power devices 21. The heat dissipation surface is mounted on the side of the cooling channels 3.

[0039] In a preferred embodiment, the heat dissipation water channel 3 has an opening on the side of the water channel body near the base plate 2 that communicates with the water channel inner cavity 32. The base plate 2 is connected to the water channel body, and the water channel inner cavity 32 is sealed by a sealing ring 33. The sealing ring 33 is preferably a sealing rubber ring, or can be made of plastic, and is used to seal the junction between the base plate 2 and the water channel inner cavity 32 at the opening on the side of the water channel body near the base plate 2.

[0040] The present invention further provides an on-vehicle charger, comprising the heat dissipation structure of the power device 21 as described above. The on-vehicle motor controller may also use the heat dissipation structure of the power device 21 provided by the present invention.

[0041] The heat dissipation structure of the power device 21 and the on-board charger provided by the present invention are assembled as follows:

[0042] First, pins 23 are integrally formed on the metal substrate 2. The power device 21 (the power device 21 is surface mounted and reflowed instead of plug-in, improving consistency), power copper busbar 26, control circuit 22, signal terminals 24, and support copper busbar 25 are then soldered to the working surface of the metal substrate 2 via reflow soldering. Thermal grease is then applied to the mounting surface of the heat dissipation channel 3. The metal substrate 2 is then placed close to the mounting surface of the heat dissipation channel 3 and placed on the base 34. The clamping member 4 is then secured to the base 34 using screws 5. The clamping member 4 presses the metal substrate 2 against the heat dissipation channel 3. The conductors in the slots or holes 13 of the PCB 1 are then soldered to the corresponding connectors on the substrate 2 (the pads 231 of the pins 23 are wave soldered to the corresponding conductors on the sidewalls of the first slot 11), enabling the transmission of power and control signals. At the same time, place the supporting copper bar 25 on the top of the pillar 31, and the top of the supporting copper bar 25 is supported on the bottom end of the PCB board 1. Pass the screw 5 through the corresponding mounting holes of the PCB board 1 and the supporting copper bar 25 and screw it into the threaded hole at the top of the pillar 31 to support the PCB board 1.

[0043] The heat dissipation structure of the power device 21 and the on-board charger provided by the present invention are as follows when in operation:

[0044] When the power circuits on the PCB board 1 and the metal substrate 2 are working, coolant is introduced into the water channel body of the heat dissipation water channel 3 from the water inlet and filled into the water channel inner cavity 32. The coolant flows in the water channel inner cavity 32 and flows out of the water channel body through the water outlet on the water channel body. At this time, the heat generated by the power device 21 on the metal substrate 2 is transferred to the heat dissipation water channel 3 through the metal substrate 2 and the heat conductive layer. Finally, the heat is carried away by the coolant in the water channel inner cavity 32 of the heat dissipation water channel 3, thereby achieving heat dissipation of the power device 21 in the heat dissipation solution.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A heat dissipation structure comprising a base, a heat dissipation channel provided on the base, and a PCB board located above the heat dissipation channel and electrically connected to a power device, characterized in that: Also includes: a substrate located on a side of the heat dissipation channel and utilizing the heat dissipation channel for heat dissipation, the power device being mounted on the substrate; The top of the substrate is provided with at least one plug port electrically connected to the power device, the PCB board is provided with a slot allowing the plug port to be inserted, and the slot is provided with a conductor for electrically connecting to the plug port; The heat dissipation water channel includes a water channel body, at least one side of the water channel body is a mounting surface, the heat dissipation surface of the substrate is mounted in contact with the mounting surface, and a heat conductive layer is filled between the heat dissipation surface and the mounting surface; The substrate is a metal substrate, the side of the substrate away from the heat dissipation channel is the working surface, and the side close to the heat dissipation channel is the heat dissipation surface, and the heat dissipation surface is installed on the side of the heat dissipation channel.

2. The heat dissipation structure according to claim 1, wherein: The substrate is parallel to the side of the heat dissipation channel, and the substrate and the PCB board are perpendicular to each other.

3. The heat dissipation structure according to claim 1, wherein: The heat dissipation water channel also includes a water inlet and a water outlet provided on the water channel body, a water channel inner cavity provided in the water channel body and used to accommodate coolant, and the water channel inner cavity connects the water inlet and the water outlet.

4. The heat dissipation structure according to claim 3, wherein: An opening communicating with the inner cavity of the water channel is provided on one side of the water channel body. The base plate covers the opening and seals the inner cavity of the water channel via a sealing ring.

5. The heat dissipation structure according to any one of claims 1 to 4, characterized in that: The substrate is pressed against the side surface of the heat dissipation channel by a pressing piece, and the pressing piece is provided with a notch corresponding to the position of the power device.

6. The heat dissipation structure according to any one of claims 1 to 4, characterized in that: The base is provided with at least one pillar, and the substrate is provided with a supporting copper bar corresponding to the pillar and extending toward the pillar. One end of the supporting copper bar is clamped and installed between the top of the pillar and the PCB board, and the other end of the supporting copper bar is connected to the substrate.

7. The heat dissipation structure according to any one of claims 1 to 4, characterized in that: The working surface is also provided with a control circuit electrically connected to the power device.

8. A vehicle-mounted charger, characterized in that: The heat dissipation structure comprises the heat dissipation structure according to any one of claims 1 to 7.

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