Heat dissipation system of PCB stator axial magnetic flux motor drive circuit

Abstract

The invention discloses a heat dissipation system of a PCB stator axial magnetic flux motor driving circuit, and relates to the technical field of motor driving heat management. According to the system, a DBC ceramic substrate serves as a core heat conduction carrier and is matched with a high-heat-conduction interface material to form a low-resistance heat conduction channel, heat generated by power devices such as an IPM is conducted to a motor shell through a heat dissipation support, and natural convection and radiation heat dissipation are enhanced through composite heat dissipation fins of the motor shell; and meanwhile, temperature sensing intelligent temperature control is integrated, and real-time temperature monitoring and protection are achieved. Through collaborative design of material selection, structure integration, thermal circuit optimization and intelligent control, the overall thermal resistance is remarkably reduced, the heat dissipation efficiency and the structural strength are improved, the problems that a high-power-density PCB stator axial magnetic flux motor driving circuit is concentrated in heating and difficult in heat dissipation can be effectively solved, and the service life of the motor is prolonged. The motor is suitable for scenes of new energy automobiles, industrial servo, frequency conversion household appliances, robot joint motors and the like.

Description

Technical Field

[0001] This invention belongs to the field of heat dissipation technology for motor drive circuits, specifically relating to a heat dissipation system for PCB stator axial flux motor drive circuits. Background Technology

[0002] With the continuous development of motor technology, PCB stator axial flux motors have been widely used in various fields due to their compact structure and high efficiency. However, high-heat components such as the DC / DC converter, PCB stator coils, and inverter circuit in the motor drive circuit generate a large amount of heat during operation. If this heat cannot be dissipated effectively and in a timely manner, it will seriously affect the performance and lifespan of the motor. Currently, common heat dissipation methods include forced cooling by fans and heat sinks, but these methods suffer from high cost, high noise, and low heat dissipation efficiency. Especially in applications with strict requirements on noise and cost, traditional heat dissipation methods are insufficient. Therefore, developing an efficient and low-cost heat dissipation design method and system is particularly important.

[0003] Existing PCB stator axial flux motor drive circuit cooling systems still have significant technical limitations in addressing the heat dissipation of high-heat components, mainly in the following three aspects:

[0004] Firstly, the heat dissipation efficiency is low: traditional heat dissipation methods, such as heat sinks, are limited by the thermal conductivity of the materials and the heat dissipation area, making it difficult to quickly transfer heat from high-heat components to the external environment, resulting in excessively high component temperatures and affecting performance.

[0005] Secondly, the cost is high: although forced cooling by fans can improve heat dissipation efficiency, it requires additional motors and fans, which increases system cost and power consumption. At the same time, the noise generated by the fan operation does not meet the requirements of some occasions.

[0006] Third, poor reliability: After long-term operation, the heat dissipation material of traditional heat dissipation methods is prone to aging, which leads to a decline in heat dissipation performance and may even cause overheating and damage to components, affecting the overall reliability of the motor.

[0007] The aforementioned defects collectively restrict the development of heat dissipation technology for PCB stator axial flux motor drive circuits, and a new type of heat dissipation system with high efficiency, low cost, and high reliability is urgently needed to achieve a breakthrough. Summary of the Invention

[0008] This disclosure provides a heat dissipation system for a PCB stator axial flux motor drive circuit, aiming to solve the heat dissipation problem of motor drive circuits caused by low heat dissipation efficiency, high cost and poor reliability in the prior art.

[0009] According to an embodiment of this disclosure, a heat dissipation system for a PCB stator axial flux motor drive circuit includes a high thermal conductivity substrate module, a thermally conductive material bonding module, a heat conduction module, a natural air convection heat dissipation module, and a temperature monitoring and control module. The high thermal conductivity substrate module uses a DBC ceramic substrate, and the IPM module of the PCB stator axial flux motor is fixed to the DBC ceramic substrate. The thermally conductive material bonding module fills the interface between the IPM module and the DBC ceramic substrate. The heat conduction module includes a heat dissipation bracket; one end of the heat dissipation bracket is tightly bonded to the DBC ceramic substrate, and the other end is fixedly connected to the motor housing. The natural air convection heat dissipation module is composed of composite heat dissipation fins on the motor housing. The temperature monitoring and control module collects the temperature of key nodes in real time through a temperature sensor and is electrically connected to the motor drive circuit to achieve graded temperature control protection.

[0010] In some embodiments, the DBC ceramic substrate is composed of a top thick copper layer, a middle ceramic insulating layer and a bottom copper layer. The ceramic insulating layer is made of alumina ceramic, silicon nitride ceramic or aluminum nitride ceramic, and the surface of the DBC ceramic substrate is treated with a double-layer process of nickel plating and gold plating.

[0011] In some embodiments, a locally thickened copper layer is provided in the mounting area of ​​the IPM module on the surface of the DBC ceramic substrate.

[0012] In some embodiments, the thermally conductive material bonding module is made of high thermal conductivity silicone grease, thermally conductive gel or phase change thermally conductive sheet, with a thickness of 0.1-0.2 mm, and the bonding interface is pretreated by plasma cleaning.

[0013] In some embodiments, the heat dissipation bracket is made of aluminum alloy, one end of which is fixedly connected to the DBC ceramic substrate through the thermal conductive material bonding module, and the other end is fixedly connected to the motor housing by laser welding or by tightly bonding with the thermal conductive material bonding module.

[0014] In some embodiments, the motor housing is made of aluminum alloy and its surface is provided with a plurality of axial and radial composite heat dissipation fins.

[0015] In some embodiments, axial fins are arranged along the motor axis, with a height of 15-20 mm, a thickness of 1.5-2 mm, and a spacing of 4-6 mm; radial fins are arranged along the circumference of the motor, with a height of 10-15 mm, a thickness of 1-1.5 mm, and a spacing of 3-5 mm.

[0016] In some embodiments, the surface of the motor housing is treated with anodizing and black powder coating.

[0017] In some embodiments, the temperature sensor of the temperature monitoring and control module is a plurality of NTC thermistors, which are respectively arranged on the mounting area of ​​the IPM module on the surface of the DBC ceramic substrate and on the inner side of the motor housing.

[0018] In some embodiments, a temperature sensor is integrated inside the MCU of the PCB stator axial flux motor to monitor the operating temperature of the drive chip of the PCB stator axial flux motor, thereby achieving end-to-end temperature monitoring.

[0019] Beneficial effects This invention, through multi-module collaborative design, effectively solves many technical problems related to heat dissipation and system operation in traditional drive circuits, significantly improving the overall performance and market competitiveness of the product. Specific technical effects are as follows: Using a high thermal conductivity substrate module as the mounting and heat dissipation foundation for the drive circuit provides efficient heat dissipation support from the source, completely solving the technical problems of low heat dissipation efficiency and easy overheating of traditional heat dissipation methods; the thermal conductive material bonding module uses thermally conductive silicone grease as the thermal conductive medium, ensuring close contact with high-heat-generating components in the drive circuit, minimizing the contact thermal resistance between components and the thermal conductive structure, achieving rapid and effective heat conduction, successfully overcoming the defects of high thermal resistance and poor heat conduction in traditional thermal conductive structures; the heat conduction module, through optimized layout and structural design of the heat conduction path, shortens the heat conduction distance, reduces heat loss during conduction, and further improves the heat dissipation efficiency of the entire heat dissipation system; the natural air convection heat dissipation module, relying on the heat dissipation fin structure, effectively promotes the natural flow of surrounding air, eliminating the need for additional active heat dissipation components such as fans, achieving low cost... The system offers stable, noiseless heat dissipation, reducing energy consumption. The temperature monitoring and control module collects real-time temperature data during system operation. When the temperature reaches a preset threshold, it automatically activates corresponding protection mechanisms, effectively preventing circuit damage and performance degradation caused by overheating, significantly improving system reliability and safety. During the overall system design process, optimized material selection and structural layout effectively reduced production costs while ensuring heat dissipation performance and operational stability, significantly improving the product's cost-effectiveness. Simultaneously, the rational selection of high thermal conductivity substrates and materials ensures structural stability and durability under prolonged high-load operation, extending product lifespan. The special structural design of the heat sink fins further increases the heat dissipation surface area, accelerating heat exchange with air and further improving heat dissipation efficiency. Furthermore, the system boasts excellent scalability, allowing for customized structural adjustments and functional adaptations based on the installation requirements of different motor models and heat dissipation needs in various scenarios, making it widely adaptable and highly practical. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the PCB stator axial flux motor of the present invention; Figure 2 This is a cross-sectional view of the heat dissipation system of the PCB stator axial flux motor of the present invention. Figure 3 This is a schematic diagram of the main structure of the PCB stator axial flux motor heat dissipation system of the present invention. Detailed Implementation

[0021] To make the technical solution and beneficial effects of the present invention more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0022] This disclosure is not exhaustive, but merely illustrative of some embodiments, and is not intended to limit the scope of protection of this disclosure. Unless otherwise specified, each step in a particular embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a particular embodiment can also be implemented as an independent embodiment, and the order of the steps in a particular embodiment can be arbitrarily interchanged. Furthermore, the optional implementation methods in a particular embodiment can be arbitrarily combined; moreover, the embodiments can be arbitrarily combined, for example, some or all steps of different embodiments can be arbitrarily combined, and a particular embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0023] In each of the disclosed embodiments, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of the embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0024] The terminology used in the embodiments of this disclosure is for the purpose of describing specific embodiments only and is not intended to limit the scope of this disclosure. In the embodiments of this disclosure, unless otherwise stated, elements expressed in the singular form, such as "a," "an," "the," "the," "the," "the," "the," "the," "this," etc., can mean "one and only one," or "one or more," "at least one," etc. For example, when using articles such as "a," "an," "the," etc. in translation, the noun following the article can be understood as either a singular or a plural expression.

[0025] In the embodiments disclosed herein, "multiple" refers to two or more.

[0026] In some embodiments, the terms “at least one of”, “one or more”, “a plurality of”, “multiple”, etc., may be used interchangeably.

[0027] In some embodiments, the notation "at least one of A and B", "A and / or B", "A in one case, B in another", "A in one case, B in another", etc., may include the following technical solutions depending on the situation: in some embodiments, A (A is executed regardless of B); in some embodiments, B (B is executed regardless of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, both A and B are executed. The same applies when there are more branches such as A, B, C, etc.

[0028] In some embodiments, the notation "A or B" may include the following technical solutions, depending on the situation: in some embodiments, A (execution of A regardless of B); in some embodiments, B (execution of B regardless of A); in some embodiments, selective execution from A and B (A and B are selectively executed). The same applies when there are more branches such as A, B, and C.

[0029] The prefixes "first," "second," etc., used in the embodiments of this disclosure are merely for distinguishing different descriptive objects and do not impose restrictions on the position, order, priority, value, or content of the descriptive objects. The description of the descriptive objects should be found in the claims or the context of the embodiments, and the use of prefixes should not constitute unnecessary restrictions. For example, if the descriptive object is a "field," the ordinal numbers preceding "field" in "first field" and "second field" do not restrict the position or order of the "fields." "First" and "second" do not restrict whether the "fields" they modify are in the same message, nor do they restrict the order of "first field" and "second field." Similarly, if the descriptive object is a "level," the ordinal numbers preceding "level" in "first level" and "second level" do not restrict the priority between "levels." Furthermore, the value of the descriptive object is not limited by ordinal numbers and can be one or more. For example, in "first device," the value of "device" can be one or more. Furthermore, the objects modified by different prefixes can be the same or different. For example, if the object being described is "device", then "first device" and "second device" can be the same device or different devices, and their types can be the same or different. Similarly, if the object being described is "information", then "first information" and "second information" can be the same information or different information, and their content can be the same or different.

[0030] In some embodiments, “including A,” “containing A,” “for indicating A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0031] In some embodiments, terms such as “…”, “determine…”, “in the case of…”, “when…”, “when…”, “if…”, etc. can be used interchangeably.

[0032] In some embodiments, the terms “greater than,” “greater than or equal to,” “not less than,” “more than,” “more than or equal to,” “not less than,” “higher than,” “higher than or equal to,” “not lower than,” and “above” can be used interchangeably, as can the terms “less than,” “less than or equal to,” “not greater than,” “less than,” “less than or equal to,” “not more than,” “lower than,” “lower than or equal to,” “not higher than,” and “below”.

[0033] Furthermore, each element, each row, or each column in the table of this disclosure can be implemented as an independent embodiment, and any combination of any element, any row, or any column can also be implemented as an independent embodiment.

[0034] Example 1 like Figure 1 , Figure 2 and Figure 3 As shown, a PCB stator axial flux motor has an IPM module 1 located at the window area 5 of the PCB stator 4, and an FOC drive circuit is also provided on the PCB stator 4. To address the heat dissipation problem of high-heat-generating components (such as the IPM module 1) in the aforementioned PCB stator axial flux motor drive circuit, this embodiment provides a heat dissipation system for the PCB stator axial flux motor drive circuit. Through multi-level and multi-dimensional structural and material optimization, efficient, low-noise, and highly reliable heat dissipation of the drive circuit can be achieved.

[0035] The heat dissipation system mainly consists of five core units: a high thermal conductivity substrate module, a thermally conductive material bonding module, a heat conduction module, a natural air convection heat dissipation module, and a temperature monitoring and control module. These modules work collaboratively to form a complete closed-loop thermal management system. The high thermal conductivity substrate module uses a DBC ceramic substrate 2 with a nickel-plated surface to improve adhesion to the thermally conductive material. In the thermally conductive material bonding module, a high thermal conductivity, low thermal resistance silicone grease is uniformly applied to the surface of high-heat-generating components or the thermally conductive substrate using an automated coating process. The heat conduction module includes a heat dissipation bracket 3. One end of the bracket 3 is tightly bonded to the high thermal conductivity substrate module via thermally conductive material, while the other end is fixedly connected to the motor housing 6, ensuring rapid heat transfer to the motor housing 6. In the natural air convection heat dissipation module, the motor housing 6 is made of aluminum alloy with several axial and radial composite heat dissipation fins on its surface to promote airflow. The temperature monitoring and control module monitors the temperature in real time and automatically reduces the motor power when the temperature exceeds a set threshold. It is precisely because of this optimized material selection and structural design that the heat dissipation system can solve the heat dissipation problem of the motor drive circuit efficiently and at low cost.

[0036] In the PCB stator axial flux motor drive circuit of the present invention, the IPM module 1 is fixed on the high thermal conductivity substrate module, which is the first receiving layer of the entire heat dissipation system and can quickly dissipate the heat of the components. The high thermal conductivity substrate module uses a copper-based DBC ceramic substrate 2 as its core substrate. Compared with the traditional FR-4 PCB substrate, the DBC ceramic substrate 2 has three core advantages: ① Thick copper layers at the top and bottom, with a thickness of 0.3-0.8mm, which can be selected according to current carrying requirements. At the same time, the thermal conductivity of copper is as high as 401W / (m·K), which can quickly dissipate the heat generated by the components; ② The middle layer uses high-purity alumina (Al2O3), silicon nitride (SiN), or aluminum nitride (AlN) ceramic insulation layers. Among them, Al2O3 ceramic insulation withstand voltage ≥5kV and thermal conductivity of about 24W / (m·K), while AlN ceramic thermal conductivity can reach 170-230W / (m·K), balancing insulation and thermal conductivity, and achieving safe isolation between strong and weak currents; ③ The coefficient of thermal expansion (CTE) is highly matched with the silicon-based chip (IGBT / MOSFET chip inside the IPM), which can significantly reduce thermal stress during temperature cycling, avoid chip solder joint cracking and substrate warping, and improve the long-term reliability of the system.

[0037] Surface treatment process: The surface of the DBC ceramic substrate 2 is treated with a dual-layer process of nickel (Ni) plating and gold (Au) plating. The nickel plating layer is 1-3μm thick, which can effectively prevent copper layer oxidation and improve surface hardness and wear resistance. The gold plating layer is 0.05-0.1μm thick, which further enhances surface wettability and oxidation resistance, significantly improves the adhesion between the DBC ceramic substrate 2 and the thermal grease, eliminates interface air gaps, and reduces interface thermal resistance. At the same time, for the mounting area of ​​the IPM module 1, a locally thickened copper layer design is adopted to further improve local heat conduction capacity and match the high heat flux density heat dissipation requirements of the IPM module 1.

[0038] Example 2 This embodiment further optimizes the thermal conductive material bonding module based on Embodiment 1. A novel thermal conductive silicone grease material is used, which not only possesses high thermal conductivity but also excellent insulation and high-temperature resistance. Simultaneously, the automated coating process is optimized, ensuring a more uniform and bubble-free application of the high thermal conductivity silicone grease through precise control of the coating amount and speed. Furthermore, a post-coating curing process is added to improve the adhesion strength between the high thermal conductivity silicone grease and high-heat-generating components, further reducing thermal resistance. It is precisely because of this optimized thermal conductive material bonding module that the system can conduct heat more effectively and improve heat dissipation efficiency.

[0039] This module is crucial for connecting high-heat-generating components to the DBC ceramic substrate 2, and the DBC ceramic substrate 2 to subsequent heat dissipation structures. Its core function is to eliminate interface gaps, reduce interface thermal resistance, and ensure lossless heat conduction.

[0040] Thermal material selection: High thermal conductivity, low thermal resistance, and high reliability silicone grease-based thermal conductive materials are selected, with a thermal conductivity ≥8W / (m·K), thermal resistance ≤0.05℃·in² / W, and an operating temperature range of -50℃ to 150℃. These materials possess excellent aging resistance and resistance to high and low temperature shocks, with no silicone oil seepage, thus avoiding circuit contamination. For the high heat flux density IPM module 1, thermal conductive gel or phase change thermal pads can be used as supplementary materials. Phase change thermal pads soften after reaching the phase change temperature (approximately 50℃), perfectly filling the microscopic gaps at the interface and further reducing thermal resistance.

[0041] Coating process control: An automated, high-precision dispensing / coating process is employed. A vision positioning system precisely locates the mounting areas of heat-generating components such as the IPM module 1, controlling the silicone grease coating thickness between 0.1-0.2mm (the optimal thickness range; too thick a layer increases thermal resistance, while too thin a layer fails to completely fill gaps). The coating uniformity error is ≤±0.02mm, ensuring the silicone grease completely covers the bonding surfaces of the components and the DBC ceramic substrate 2, without bubbles or missing adhesive. After coating, curing is performed to ensure complete curing of the silicone grease, forming a stable thermally conductive interface.

[0042] Interface pretreatment: Before applying thermal grease, plasma cleaning is performed on the surface of DBC ceramic substrate 2 and the bottom of IPM module 1 to remove surface oil, oxide layer and impurities, increase surface energy, enhance the adhesion between the grease and the substrate, further reduce interface thermal resistance and improve thermal conductivity reliability.

[0043] Example 3 This embodiment optimizes the heat conduction module, which includes a heat dissipation bracket 3. The heat dissipation bracket 3 is made of aluminum alloy. One end is fixedly connected to the DBC ceramic substrate 2 via a thermally conductive material bonding module, and the other end is fixedly connected to the motor housing 6 using laser welding or by tightly bonding with the thermally conductive material bonding module. The heat dissipation bracket 3 is U-shaped and elastic, allowing for a tighter connection between the DBC ceramic substrate 2 and the IPM module 1. When using the thermally conductive material bonding module to fix the heat dissipation bracket 3 to the motor housing 6, in addition to tightly bonding the motor housing 6 with thermally conductive material, a thermally conductive adhesive layer is added to further improve heat conduction efficiency. The thermally conductive adhesive layer uses a high thermal conductivity, low viscosity adhesive. By precisely controlling the amount and position of the adhesive, a uniform, bubble-free adhesive layer is ensured. Simultaneously, the curing process is optimized to create a good heat conduction channel after curing. Furthermore, surface treatments such as sandblasting or anodizing are applied to the motor housing to increase surface roughness and expand the contact area with the thermally conductive adhesive layer, further improving heat transfer efficiency. It is precisely this optimized heat transfer module that enables the system to transfer heat from the drive circuit to the motor housing more quickly and effectively.

[0044] The heat conduction module connects the DBC ceramic substrate 2 and the motor housing 6 through a heat flow transmission channel. Its core function is to quickly and efficiently transfer the heat conducted out of the DBC ceramic substrate 2 to the heat dissipation structure of the motor housing 6, thereby achieving cross-level heat conduction.

[0045] Connection Structure Design: A tight-fitting connection structure is adopted. The bottom copper layer of the DBC ceramic substrate 2 is fixed to the aluminum heat sink bracket 3 through a high thermal conductivity and electrical conductivity adhesive (thermal conductivity ≥20W / (m·K)). The heat sink bracket 3 and the motor housing 6 are tightly connected by laser welding or through thermally conductive materials to ensure a gapless connection interface and extremely low thermal resistance. At the same time, thermally conductive silicone grease is filled between the heat sink bracket 3 and the DBC ceramic substrate 2 to further eliminate interface gaps and improve heat conduction efficiency.

[0046] Heat flow path optimization: The heat flow path is optimized through thermal simulation analysis to ensure that the heat generated by IPM module 1 is conducted along the shortest path of "IPM module 1 → DBC ceramic substrate 2 → thermal grease → heat sink bracket 3 → motor housing 6 → air", avoiding heat flow around and improving heat conduction efficiency.

[0047] Example 4 This embodiment optimizes the natural air convection cooling module. In addition to employing a heat dissipation fin design, the shape, spacing, and height of the fins are optimized. Through computer simulation and experimental verification, the optimal combination of heat dissipation fin parameters is determined, resulting in smoother airflow and higher heat dissipation efficiency. Simultaneously, air inlets and outlets are added to the motor housing 6, forming a more effective air convection channel. Furthermore, the motor housing 6 is designed to be lightweight, reducing material usage and lowering costs while maintaining sufficient structural strength. It is precisely because of this optimized natural air convection cooling module that this system can achieve highly efficient heat dissipation under low-cost and noiseless conditions.

[0048] The core function of this module is to dissipate the heat conducted to the motor housing 6 into the environment through natural air convection, thus achieving the final dissipation of heat.

[0049] Motor Housing 6 Design: The motor housing 6 is made of high-strength aluminum alloy, which has a thermal conductivity of approximately 205 W / (m·K), combining excellent thermal conductivity, mechanical strength, and corrosion resistance. The surface of the motor housing 6 is designed with several axial and radial composite heat dissipation fins. The axial fins are arranged along the motor axis, with a height of 15-20 mm, a thickness of 1.5-2 mm, and a spacing of 4-6 mm; the radial fins are arranged along the motor circumference, with a height of 10-15 mm, a thickness of 1-1.5 mm, and a spacing of 3-5 mm. The two types of fins work together to significantly increase the heat dissipation surface area (3-5 times greater than a smooth housing), while the optimized streamlined design of the fins reduces airflow resistance and promotes natural air convection.

[0050] Surface treatment process: The motor housing 6 adopts anodizing + black powder coating process. The thickness of the anodized layer is 10-20μm, which improves the surface hardness and corrosion resistance. The black powder coating layer has high emissivity, which can significantly improve the efficiency of radiative heat dissipation. On the basis of natural convection, it can remove an additional 15%-20% of the heat through radiative heat dissipation, further improving the heat dissipation effect.

[0051] Example 5 This embodiment optimizes the temperature monitoring and control module. The module employs a high-precision temperature sensor to monitor the temperature of the drive circuit and high-heat-generating components in real time. The high-precision sensor data is transmitted to the control unit via a data cable, where it makes a judgment based on a preset temperature threshold. When the temperature exceeds the set threshold, the control unit automatically reduces the motor power or activates a backup cooling fan (if equipped) to ensure safe system operation. Simultaneously, the control unit also has data recording and analysis functions, recording temperature change curves to provide a basis for optimizing the heat dissipation design. Furthermore, the control unit supports remote monitoring and alarm functions, allowing users to easily understand the system's operating status at any time. It is precisely because of this intelligent temperature monitoring and control module that the system can operate more safely and reliably.

[0052] This module is the intelligent control unit of the entire heat dissipation system. Its core function is to monitor the temperature of the drive circuit in real time, and to achieve overheat protection through active control, so as to ensure that the system operates within a safe temperature range and improve reliability.

[0053] Temperature monitoring unit: NTC thermistor temperature sensors are installed in the IPM module 1 mounting area on the DBC ceramic substrate 2 and inside the motor housing, respectively. The sensors have an accuracy of ±0.5℃ and a response time of ≤1s. They are connected to the motor drive control MCU (microcontroller unit) via wires to collect temperature data from each key node in real time. Simultaneously, a temperature sensor is integrated inside the MCU to monitor the operating temperature of the drive chip, achieving end-to-end temperature monitoring.

[0054] Threshold setting and control logic: Based on the rated operating temperature of IPM module 1, three temperature thresholds are set: ① Warning threshold (80℃): When the temperature reaches 80℃, the MCU outputs a warning signal and slightly reduces the motor output power (reduced by 5%-10%) to reduce heat generation; ② Protection threshold (100℃): When the temperature reaches 100℃, the MCU significantly reduces the motor output power (reduced by 30%-50%) and starts the fan for auxiliary heat dissipation (if equipped); ③ Shutdown threshold (120℃): When the temperature reaches 120℃, the MCU immediately shuts off the output of IPM module 1 and stops the motor from running to prevent components from overheating and being damaged.

[0055] Data interaction and fault alarm: The MCU uploads real-time temperature data to the motor host computer control system to realize real-time monitoring and historical recording of temperature data; when the temperature exceeds the warning threshold, the host computer issues an audible and visual alarm to remind the operator; when the temperature reaches the shutdown threshold, the system records the fault code to facilitate subsequent fault diagnosis and maintenance.

[0056] Thanks to the optimized material selection, structural design, and intelligent control strategies described above, the PCB stator axial flux motor drive circuit heat dissipation system of this invention can control the junction temperature of core heat-generating components such as the IPM module 1 to below 100°C. Compared with traditional heat dissipation solutions, the heat dissipation efficiency is improved by more than 40%. At the same time, it has excellent reliability, stability, and environmental adaptability. It can efficiently and cost-effectively solve the heat dissipation problem of PCB stator axial flux motor drive circuits and is suitable for various high-power-density PCB stator axial flux motor scenarios such as new energy vehicle drive motors, industrial servo motors, variable frequency home appliances, and robot joint motors.

[0057] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0058] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A heat dissipation system for a PCB stator axial flux motor drive circuit, characterized in that, The system includes a high thermal conductivity substrate module, a thermally conductive material bonding module, a heat conduction module, a natural air convection heat dissipation module, and a temperature monitoring and control module. The high thermal conductivity substrate module uses a DBC ceramic substrate (2), and the IPM module (1) of the PCB stator axial flux motor is fixed on the DBC ceramic substrate (2). The thermally conductive material bonding module fills the connection interface between the IPM module (1) and the DBC ceramic substrate (2). The heat conduction module includes a heat dissipation bracket (3). One end of the heat dissipation bracket (3) is tightly bonded to the DBC ceramic substrate (2), and the other end is fixedly connected to the motor housing. The natural air convection heat dissipation module is composed of composite heat dissipation fins on the motor housing (6). The temperature monitoring and control module collects the temperature of key nodes in real time through a temperature sensor and is electrically connected to the motor drive circuit to achieve graded temperature control protection.

2. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, The DBC ceramic substrate (2) consists of a top thick copper layer, a middle ceramic insulating layer and a bottom copper layer. The ceramic insulating layer is made of alumina ceramic, silicon nitride ceramic or aluminum nitride ceramic. The surface of the DBC ceramic substrate (2) is treated with a double-layer process of nickel plating and gold plating.

3. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 2, characterized in that, A locally thickened copper layer is provided in the mounting area of ​​the IPM module (1) on the surface of the DBC ceramic substrate (2).

4. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, The thermal conductive material bonding module uses high thermal conductivity silicone grease, thermal conductive gel or phase change thermal conductive sheet with a thickness of 0.1-0.2mm, and the bonding interface is pretreated by plasma cleaning.

5. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, The heat dissipation bracket (3) is made of aluminum alloy. One end is fixedly connected to the DBC ceramic substrate (2) through the thermal conductive material bonding module, and the other end is fixedly connected to the motor housing (6) by laser welding or by tightly bonding with the thermal conductive material bonding module.

6. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, The motor housing (6) is made of aluminum alloy and has several axial and radial composite heat dissipation fins on its surface.

7. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 6, characterized in that, Axial fins are arranged along the motor axis, with a height of 15-20mm, a thickness of 1.5-2mm, and a spacing of 4-6mm; radial fins are arranged along the circumference of the motor, with a height of 10-15mm, a thickness of 1-1.5mm, and a spacing of 3-5mm.

8. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 6, characterized in that, The surface of the motor housing (6) is treated with anodizing and black powder coating.

9. The heat dissipation system of the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, The temperature sensor of the temperature monitoring and control module uses several NTC thermistors, which are respectively arranged on the mounting area of ​​the IPM module (1) on the surface of the DBC ceramic substrate (2) and on the inside of the motor housing (6).

10. The heat dissipation system for the PCB stator axial flux motor drive circuit according to claim 1, characterized in that, A temperature sensor is integrated inside the MCU of the PCB stator axial flux motor to monitor the operating temperature of the drive chip of the PCB stator axial flux motor, thereby realizing end-to-end temperature monitoring.

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