Integrated busbars on a printed circuit board

Abstract

This invention pertains to integrated busbars configured on a power printed circuit board (PCB) (10) The integrated busbars are incorporated with a circular or radial arrangement of MOSFETs (60) on the power PCB (10). The UVW phase terminal busbars (30), is directly linked to the drive motor to manage phase currents efficiently. The configuration also features connecting busbars (20) connecting the power board (10) to the control PCB (80) via head portions (25). Additionally, the ground busbar (40) offers a common electrical reference for all PCB components, preventing potential differences that could lead to malfunctions. Connecting holes (70) present in the connecting busbars (20) facilitate utilizing interlink busbars (50), enabling a circular configuration on the PCB (10). This integration of busbars streamlines the system and enhances the overall thermal efficiency and performance of the power management system.

Description

INTEGRATED BUSBARS ON A PRINTED CIRCUIT BOARDTECHNICAL FIELD

[0001] The present invention relates to the field of electrical motor technology. In particular, the present invention particularly relates to a power board or a PCB (printed circuit board) incorporating integrated busbars within the PCB, for the purpose of increasing thermal dissipation, improving electrical performance and a more compact design.BACKGROUND LITERATURE

[0002] In the field of electrical motor technology, managing power distribution and thermal dissipation are critical challenges, particularly as power demands increase with the rise of high-efficiency systems like electric vehicles (EVs). Printed circuit boards (PCBs) play a pivotal role in managing the flow of electricity within these systems. In a PCB, busbars and MOSFETs (metal-oxide-semiconductor field-effect transistor) are fundamental to efficient power distribution, thermal management, and overall system performance, especially in high- power applications such as motor control and power inverters. Busbars are conductive bars that distribute electrical power within the PCB. They carry high currents and distribute power to various components, including the MOSFETs. MOSFETs (Metal-Oxide-Semiconductor Field- Effect Transistors) are used for switching and amplifying electrical signals in power electronics. They require a stable and efficient power supply to operate correctly.

[0003] Busbars provide the necessary power directly to the MOSFETs, ensuring that they receive the required voltage and current for their operation. This direct connection helps minimize power losses and improves the efficiency of power delivery. Busbars are designed to handle high currents and can also aid in heat dissipation due to their large surface area and thermal conductivity. MOSFETs generate heat during operation, especially when switching high currents. Proper thermal management is crucial to prevent overheating and ensure reliable performance.

[0004] Conventional designs of PCBs often struggle with heat buildup, which can lead to reduced efficiency, system failures, and increased maintenance costs. The present invention deals with the integration of busbars and MOSFETs on the PCB which helps in effective thermal management. Busbars can serve as heat sinks, dissipating the heat generated by the MOSFETs. Additionally, the layout and placement of MOSFETs in relation to the busbars can be optimized to enhance heat dissipation and reduce hotspots.

[0005] Additionally, busbars provide mechanical support and stability to the PCB, especially when handling high-power applications. MOSFETs need to be securely mounted on the PCB to ensure proper electrical connections and thermal contact with heat sinks or busbars. Hence, the mechanical stability provided by busbars supports the MOSFETs, ensuring that they remain securely in place. This stability is crucial for maintaining reliable electrical connections and effective thermal contact, which is essential for the overall performance and longevity of the PCB.

[0006] Moreover, the placement and design of busbars in relation to MOSFETs can help minimize the electromagnetic interference (EMI) by providing low-impedance paths for high- frequency currents and reducing the inductive loops. This improves the electromagnetic compatibility of the PCB and reduces the risk of interference with other electronic components.OBJECTIVE OF THE INVENTION

[0007] A primary objective of the present invention is to provide a power board or a power PCB (printed circuit board) comprising an integrated bus bar arrangement.

[0008] Another objective of the present invention is wherein the power PCB comprises a circular or a radial arrangement of MOSFETS (metal-oxide-semiconductor field-effect transistor).

[0009] Other objects of the present invention, as well as particular features, elements and advantages thereof, will be clarified in or be apparent from the following description and the accompanying figures.SUMMARY OF THE INVENTION

[0010] The following summary is provided to facilitate a clear understanding of the new features in the disclosed embodiment and it is not intended to be a full, detailed description. A detailed description of all the aspects of the disclosed invention can be understood by reviewing the full specification, the drawing and the claims and the abstract, as a whole.

[0011] An aspect of the present invention pertains to the integration of busbars on a power printed circuit board (PCB) with a circular or a radial arrangement of MOSFETs, designed to enhance system efficiency and functionality. This layout optimizes thermal management and offers a compact design, improving overall performance. The power PCB features a U, V, W busbar system, which is a three phase busbar system for phase lead current connection, directly linked to the drive motor to manage and deliver phase currents efficiently. Additionally, a connecting busbar preferably a 96V busbar connects the power board or power PCB to the control board, facilitating power distribution and communication signal transmission, eliminating extra wiring. The ground busbar provides a common electrical reference point, ensuring safety by directing fault currents to ground and minimizing electrical noise. The circular arrangement of MOSFETs allows for optimal space and thermal management, enhancing heat dissipation and performance.

[0012] Another aspect of the present invention illustrates the integration of various busbars with the radial or circular arrangement of MOSFETs on the PCB. The said arrangement of MOSFETs on a metal-clad PCB, ensures that more space is available for positioning the busbar on the PCB. Furthermore, it ensures an even heat distribution, reducing hotspots and improving thermal dissipation. This design achieves higher efficiency and power levels, making it a robust solution for power management.BRIEF DESCRIPTION OF DRAWINGS

[0013] The detailed description is described with reference to the accompanying figures. Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements and features. The features and advantages of the present proposed systemwill become more apparent from the following detailed description a long with the accompanying figures, which forms a part of this application.

[0014] Fig. 1 illustrates the integration of busbars on a circular power printed circuit board (PCB) according to a preferred embodiment of the present invention.

[0015] Fig. 2 illustrates an exploded view on the integration of busbars on the circular PCB board, according to a preferred embodiment of the present invention.

[0016] Fig. 3 illustrates a process of assembly of the integration of the busbars in the circular PCB board, comprising the circular / radial arrangement of MOSFETs according to a preferred embodiment of the present invention.

[0017] Fig. 4 illustrates a process of assembly of the UVW busbars on a circular PCB featuring a radial arrangement of MOSFETs according to the present invention.

[0018] Fig. 5 illustrates another step in the process of assembly depicting arrangement of ground busbars on the PCB according to the present invention.

[0019] Fig. 6 further illustrates an additional step in the process of assembly depicting arrangement of the integrated connecting busbars on the said PCB according to the present invention.

[0020] Fig. 7 further illustrates another step in the process of assembly depicting the interlink busbars providing connection between the connecting busbars of the said PCB according to the present invention.

[0021] Fig. 8 illustrates a schematic view of the radial or a circular arrangement of MOSFETs on the power PCB board according to the present invention.

[0022] Fig. 9 illustrates a schematic view wherein a control PCB board is inverted to be affixed to the power PCB board according to the present invention.

[0023] It is to be noted, however, that the appended drawing illustrates only typical embodiments of this system and are therefore should not be considered limiting of its scope, for the system may admit to other equally effective embodiments.LIST OF REFERENCE NUMERALS10 - power printed circuit board (PCB)20 - connecting busbars25 - head portion30 - U, V, W phase terminals40 - ground busbars50 - interlink busbars60 - MOSFETs70 - connecting holes80 - Control printed circuit board (PCB)90 - ScrewsDETAILED DESCRIPTION OF THE INVENTION

[0024] The following is a detailed description of the present disclosure depicted in the accompanying drawings. However, it may be understood by a person having ordinary skill in the art that the present subject matter may be practiced without these specific details. The subject matter of the disclosure will be more clearly understood from the following description of the embodiments thereof, given by way of example only with reference to the accompanying drawings, which are not drawn to scale.

[0025] If the specification states that a component or a feature “may” or “can” be included, that particular component or feature is not required to be included or have the characteristic. The use of open-ended terms like “comprising” and variations herein is meant to encompass the steps listed thereafter and equivalents thereof as well as additional items. As used herein, the singular forms “a,” “an,” and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.

[0026] The term “PCB” refers to Printed Circuit Board. The term “UVW” refers to the three-phase power supply system used in electrical engineering, where each letter (U, V, W) typically represents one of the three phases: U for Phase 1, V for Phase 2, and W for Phase 3. The term “MOSFET” refers to metal-oxide-semiconductor field-effect transistor. It is a type of field-effect transistor (FET) that is used to amplify or switch electronic signals. The term RGB refers to the three different phases in an AC system. These phases may be identified as "R" (Red), "G" (Green), and "B" (Blue), similar to the U, V, W phases. The term “96Volt” and “96V” have been used interchangeably. The term “circular arrangement” and “radial arrangement” of MOSFETs have been used interchangeably. The term power PCB and power board has been used interchangeably. The term control board and control PCB has been used interchangeably.

[0027] The present invention relates to an arrangement comprising an integration of busbars arranged on a power printed circuit board (PCB) board, featuring a radial or a circular arrangement of MOSFETs. The present invention therefore discloses the arrangement of various busbars on a power board, specifically designed to enhance the efficiency and functionality of a control system of a motor, specifically a drive motor system of an electric vehicle, as depicted in Fig.l. Stated otherwise, the present invention also relates to the integration of the control board busbars and the motor board busbars on the PCB board of the present invention. This layout or arrangement not only ensures optimal thermal management but also allows for a more organized and compact design, thereby improving the overall performance of the power board. It is observed that that the integration of connecting busbars (20) is done on a circular power PCB (10) featuring a circular / radial arrangement of MOSFETS(60), as depicted in Fig.1. It is noted that this radial or circular MOSFET arrangement facilitates the proper integration of busbars, providing ample space for effective busbar implementation.

[0028] Fig.2 illustrates an exploded view of the electrical assembly, wherein the components of this configuration comprising of the UVW (or RGB) phase terminal busbars (30), which is essential for three phase lead current connection in the PCB (10). Each of the busbars (U, V, W) (30) corresponds to one phase of the power which is directly connected to the drive motor (not shown here), with its three terminals facilitating a seamless connection. The U, V, W busbars (30) ensures that the phase currents are efficiently managed and delivered to the drive motor, enhancing the operational efficiency and reliability of the motor drive system.

[0029] In addition to the UVW busbar, the design incorporates conductive elements used to distribute power to different parts of the system., such as the interlink busbars (50) that connects the power board to the control board through protrusions provided in the head of the connecting busbars (20), as seen in Fig.2. According to a preferred embodiment of the present invention, the connecting busbars (20) utilized here may be of 96 Volts. This busbar plays a critical role in power distribution and communication signal transmission between the power PCB (10) and the control PCB (80). The busbars are essential for maintaining electrical connectivity between various components without using individual wires, allowing for cleaner and more efficient distribution of power.

[0030] Referring back to Fig.2, the connecting busbars (20) is a primary busbar for distributing power, connected to a power source and provide high voltage to the system components. As seen in Figs.2 to 9, it is noted that each of the connecting busbars (20) comprise a pair of head portions (25). By linking the head portion (25) of the connecting busbars (20) with the control PCB (not shown here) , the invention ensures a direct and reliable connection between the power and control PCBs, for power and communication purposes, eliminating the need for additional wiring and components. The strategic integration of these busbars on the power board streamlines the system design, reduces complexity, and enhances the overall efficiency and performance of the power management system.

[0031] Additionally, the ground busbar (40) depicted in Fig.2 provides a common electrical reference point for all the components on the power PCB (10). It ensures that all parts of the circuit share the same ground or neutral potential, preventing potential differences that could cause malfunction or damage. It also provides a common return path for electrical currents and ensures safety by minimizing the risk of electrical faults.

[0032] Coming back to Fig.2, the power PCB (Printed Circuit Board) (10) being the base of the assembly, provides mounting and electrical connections for various electronic components and busbars. According to Fig. 2, the power PCB (10) is designed in a circular shape, allowing for the radial arrangement of MOSFETs (60). It is integrated with multiple busbars, including the connecting busbars (20) that may be 96 volts, U, V, W phase terminal busbars (30), and the ground busbars (40). This integration enables efficient power distribution and seamless connection between the power system and the control circuitry, optimizing the overall functionality of the assembly.

[0033] Stated otherwise, Fig.2 demonstrates the flow of control and power in a motor system. The control board sends control signals to the power PCB, which also supplies power to the control board for its operation. The power PCB, in turn, controls the motor's phase current based on inputs from the control board. The motor receives its power from the power board to function. The control PCB works on DC, while the motor works on AC. Hence, a connecting busbar (20) draws current from the battery, and a power PCB converts DC to AC. The UVW busbar then supplies this current to the motor to operate it.

[0034] Fig.3 illustrates the assembly of the various busbars, on the power PCB , alongside the circular arrangement of MOSFETs on the said PCB. This configuration is critical for efficient power distribution and control in the system. The MOSFETS (60) are laid out as a circular / radial layer arrangement on the PCB board (10), wherein there is a first layer, a second layer and middle layer of the MOSFET arrangement. Furthermore, the circular / radialarrangement of MOSFETs may be on a metal-clad PCB (10), which ensures space is available for positioning the busbars on the PCB.

[0035] The power PCB further includes integrated busbars, with one section dedicated to directly connecting to the motor, ensuring it receives the required high-voltage power for optimal operation. A head portion (25) of the busbar is designed to physically link with the control board (not shown here), enabling efficient power transfer and coordination between the power and control systems. As depicted in Fig.3, the connecting busbars which are three in number and may carry 96 volts, are arranged in a circular configuration on the power PCB.

[0036] The control PCB (not shown here) generates control signals (e.g., PWM signals) that direct the operation of the power PCB but does not directly connect to the motor. Instead, it communicates with the power PCB to modulate how much power is delivered to the motor. This connection provides the control circuitry with the required power to manage and regulate the motor’s functions and other system operations.

[0037] The ground busbar (40) provides a common electrical reference point for all components on the PCB. It ensures safety by directing fault currents to ground and minimizes electrical noise, which is crucial for the stable operation of sensitive electronic components. The MOSFETs (60) arranged in a radial / circular pattern on the power PCB (10), as depicted in Figures 2 and 3, are designed to optimize space and thermal management. The circular arrangement of MOSFETs (60) on a metal-clad PCB, ensures space is available for positioning the busbars on the PCB along with efficient heat dissipation and better performance of the MOSFETs.

[0038] The integration of the control board busbar and the motor busbar with the circular arrangement of MOSFETs is another crucial aspect of the PCB design. This configuration facilitates seamless power distribution and control signal management between the control board and the motor. The connecting busbars, connected to the power PCB and connected with the control PCB board, ensure that both the high-power requirements of the motor and theprecise control needs of the control circuitry are met efficiently. This dual-busbar system enhances the overall reliability and performance of the system.

[0039] Fig.3 therefore, demonstrates a step-by-step assembly process for the integration of various busbars along with a circular / radial arrangement of MOSFETs (60) on the circular PCB. As depicted in Figures 2 and 3, the PCB has a circular layout, with MOSFETs and other electronic components arranged in a radial configuration, likely for efficient power control and heat dissipation. The first layer of busbars added includes the U, V, and W phase terminal busbars (30), which correspond to the three-phase electrical connections. The ground busbars (40) are installed next, providing a return path for electrical currents and ensuring system safety by grounding the circuit. The connecting busbars (20) is the next component added to the assembly. According to Fig.3, three connection busbars are connected and integrated using connection mechanisms such as interlink busbars (50) that allow them to form a circular design. The said busbars (20) are equipped with connecting holes (70) that facilitate the use of these interlink busbars, enabling them to be configured into a circular ring. Additionally, the interlink busbar mechanisms (50) are employed to join these said busbars (20) and ensure the proper distribution of the power throughout the system. Consequently, the connecting busbars are combined to create a single continuous circular busbar through the connection holes (70) utilizing the interlink busbar (50). Moreover, the head portions (25) of the connecting busbars can be linked with the control board PCB to facilitate transfer of power from the power PCB to the control PCB, enabling the control PCB to regulate and distribute power as needed for the EV's systems.

[0040] Figs. 4 to 7 provide detailed schematic representations of the components of the integrated busbar PCB showcasing their arrangement and assembly process. These figures highlight the integrated busbars along with a circular or radial arrangement of MOSFETs (60) on the PCB (10) according to the key aspect of the present invention. The step-by-step process of assembly of the present invention is clearly depicted in figures 4 to 7, further expanding on the sequence already outlined in Figs. 2 and 3.

[0041] Figs. 4 to 7 illustrate the step-by-step assembly of busbars and the radial arrangement of MOSFETs (60) on the circular PCB, designed for efficient power control and heat dissipation. Fig. 4 depicts that the assembly begins with the installation of the U, V, and W phase terminal busbars (30) for three-phase connections, followed by the ground busbars (40) for grounding the battery power, depicted in Fig.5. Next, the three connecting busbars (20) are added, interlinked using busbar mechanisms (50) through connecting holes (70), forming a continuous circular ring, depicted in Figs 6 and 7. These busbars can then be connected to the control PCB (not shown here), facilitating power transfer and enabling the control PCB to regulate the EV’s systems.

[0042] Together, these figures comprehensively demonstrate how the busbars and MOSFETs are systematically combine the power and control PCBs to create the final structure.

[0043] In prior arts, the conventional MOSFET arrangement on a metal-clad PCB board was uneven, leading to inconsistent heat distribution. The irregular spacing between the MOSFETs caused certain areas to overheat while others remained relatively cooler, compromising the overall thermal performance of the board. This uneven heat distribution not only affected the efficiency of the MOSFETs but also posed potential risks of thermal damage, thereby reducing the reliability and lifespan of the components.

[0044] In response to these thermal management issues, a new configuration was implemented as shown in Fig. 8. The MOSFETs (60) were arranged in a circular or a radial pattern on the PCB board (10), optimizing the spacing between each component. Moreover, a circular metal clad PCB board was also adopted.

[0045] This circular or radial arrangement of MOSFETS (60) on the circular PCB board (10) ensured that the heat generated by the MOSFETs was more evenly distributed across the board, mitigating the hotspots and enhancing the overall thermal dissipation. By improving the spatial configuration of the MOSFETs, the new design significantly reduced the thermal gradients, leading to a more balanced temperature profile and improved reliability as seen inFig.8. Above all, the circular or the radial arrangement of MOSFETs on a metal-clad PCB, ensured that optimum space is available for positioning the integrated busbars on the PCB.

[0046] Referring back to Fig 8, the adoption of the metal-clad PCB in the new arrangement further enhanced heat dissipation due to its superior thermal conductivity. This improved design enabled the system to achieve a peak power of no less than 15KW, with reduced switching losses and higher efficiency of the inverter. The combination of optimal MOSFET spacing and the use of a metal-clad PCB has resulted in a more robust and efficient power management solution, capable of handling higher power levels with improved thermal performance and efficiency. Fig.9 shows a motor assembly highlighting the connection between the control board PCB (80) and the power board PCB (10) through busbars. The control board is responsible for sending control signals to the power PCB, then the power PCB gives power to motor for optimal working. The head projections (25) of the busbar are aligned with slots in the control board, providing the sole connection between the power board and the control board, transmitting a 96V output, according to an embodiment. Additionally, the UVW busbars are directly connected to the motor to control the motor's power by managing the phase current. The PCBs (10,80) are secured using screws (90), ensuring a stable and compact configuration. The integration of busbars between the control and power PCBs facilitates direct power transfer, optimizing the system's electrical efficiency and heat dissipation for improved overall performance.

[0047] The integrated busbars incorporated with a circular arrangement of MOSFETs on a power PCB, offers several advantages. This design maximizes space utilization and enhances thermal management by evenly distributing thermal loads, reducing hotspots, and ensuring efficient heat dissipation. The symmetrical layout minimizes inductance and resistance, crucial for high-frequency switching applications. Integrated busbars ensure stable power distribution and improve mechanical stability, supporting heavy components and reducing stress. Additionally, interlink busbars aid to form ring-like structures, further aiding even power distribution and thermal management, ensuring reliable and efficient operation of electric motor control systems.

Claims

We Claim:

1. A power management system configured for a drive motor comprising: a circular power printed circuit board (PCB) (10) with an arrangement of MOSFETs (metal-oxide-semiconductor field-effect transistor) (60), and multiple integrated busbars on the PCB (10), including: i. U, V, W phase terminal busbars (30) for three-phase current distribution and drive motor connection; ii. connecting busbars (20) for connecting the power PCB (10) to a control PCB (80); iii. ground busbars (40) to provide a common return path and reference point for electrical currents; and iv. inter-link busbars (50) to provide connection between the connection busbars (20); wherein the said PCB (10) enables a radial / circular integration of the busbars and MOSFETs (60) on the PCB (10) for efficient power control and heat dissipation.

2. The system as claimed in claim 1 , wherein the connecting busbars (20) are connected via inter-link busbars (50).

3. The system as claimed in claim 1, wherein the connecting busbars (20) comprise connecting holes (70) to employ the inter-link busbars (50) to integrate the said connecting busbars (20).

4. The system as claimed in claim 1, wherein each of the connecting busbars (20) comprise a pair of head portions on a top section of each of the said connecting busbars (20) facilitating connection between the power PCB (10) and control PCB (80) via screws (90).

5. The system as claimed in claim 1, wherein the connecting busbars (20) and the inter-link busbars (50) are 96 Volt busbars.

6. The system as claimed in claim 1, wherein the power PCB (10) is mounted on the base of a motor housing and the control PCB (80) is invertedly mounted on the said power PCB (10) via the connecting busbar (20).

7. The system as claimed in claim 1, wherein the integration of the connecting busbars (20) onto the power PCB (10) in a circular manner eliminates the need for additional wiring.

8. The system as claimed in claim 1, wherein the ground busbar ensures that all parts of the power PCB (10) have the same ground potential.

9. The system as claimed in claim 1, wherein the radial integration of the busbars and MOSFETs onto the circular PCB eliminates spacing issues.

10. The system as claimed in claim 1, wherein the radial arrangement of the MOSFETs (60) ensures even heat distribution across the PCB (10), thereby reducing hotspots and enhancing overall thermal dissipation.

11. The system as claimed in claim 1, wherein the PCB (10) is metal clad.

12. The system as claimed in claim 1, wherein a peak power output achieved by the said system is at least 15 kW with reduced switching losses and improved inverter efficiency.

13. A method for power management in a drive motor, comprising: providing a circular power printed circuit board (PCB) (10) with a radial arrangement of metal-oxide-semiconductor field-effect transistors (MOSFETs) (60) and integrating multiple busbars onto the PCB (10), including: i. employing U, V, W phase terminal busbars (30) for three-phase current distribution and connection to the drive motor; ii. connecting the PCB to a control PCB (80) via each connecting busbarsiii. establishing ground busbars (40) for a common return path and reference point for electrical currents; and iv. providing interlink busbars (50) to provide connect between the connection busbars (20); thereby facilitating efficient power control and heat dissipation through the radial / circular integration of the busbars and MOSFETS (60) on the power PCB (10).

14. The method as claimed in claim 13, comprising providing a pair of head portions (25) on a top section of each connecting busbar (20).

15. The method as claimed in claim 13, comprising positioning the head portions (25) of the connecting busbars (20) to align with corresponding slots on the control PCB (80), to provide a power flow between the power PCB (10) and control PCB (80).

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