Power supply rectification circuit structure of multilayer circuit board and assembling method

Abstract

The invention belongs to the technical field of high-frequency rectifiers, and particularly discloses a power supply rectification circuit structure of a multilayer circuit board and an assembling method, and the power supply rectification circuit structure adopts a laminated design of an aluminum substrate, a first laminated plate and a second laminated plate. N parallel power conversion circuits are arranged on the aluminum substrate at equal intervals, the first laminated plate is provided with a corresponding current limiting circuit, and the second laminated plate is provided with a driving circuit. And the laminated plate is integrated on the substrate through the contact pin, so that connection, fixation and signal transmission are realized. The power conversion circuit is a linear path with equal interval and equal length, the layout is optimized, the rectification circuit design is simplified, the path is shortened, and nodes are reduced. Compared with the prior art, the design improves the space utilization rate, enables current and signal transmission to be more direct and efficient, reduces transmission time and loss, reduces temperature rise, enhances reliability and stability, simplifies design complexity, and improves integration level and power density. The problems of heat dissipation, installation, current sharing and driving design of power MOSFETs in a high-power switching power supply are effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-frequency rectifiers, and in particular relates to a power rectifier circuit structure of a multi-layer circuit board and an assembling method thereof. Background Art

[0002] As an advanced power conversion technology, synchronous rectification is based on replacing traditional rectifier diodes with power MOSFET tubes with extremely low on-resistance. This technological innovation significantly reduces energy loss during rectification and greatly improves the efficiency of DC / DC converters. Its working principle is based on precise timing control, and an additional drive circuit is used to intelligently control the on and off of the power MOSFET tube to ensure that the action of these switching devices is highly synchronized with the current demand of the output load.

[0003] Aluminum substrate, as a metal-based copper-clad laminate with good heat dissipation function, has a unique three-layer structure (circuit layer, insulation layer, metal base layer) that provides an excellent heat conduction path for power devices. Power devices such as power MOSFET are tightly mounted on the circuit layer through surface mounting technology. The heat generated during operation is quickly conducted to the metal base layer through the insulation layer, and then the metal base layer effectively dissipates the heat to the external environment. This efficient heat diffusion treatment method significantly reduces the operating temperature of the module, extends the service life, and improves the power density and reliability. At the same time, the application of aluminum substrate also reduces the assembly requirements of heat sinks and other hardware (such as thermal interface materials), reduces the product size, and reduces hardware and assembly costs. More importantly, it optimizes the combination of power circuits and control circuits, providing strong support for the integration of circuit design.

[0004] However, in high-power switching power supply applications, the application of synchronous rectification technology faces many challenges. Due to the need to handle larger currents, multiple power MOSFET tubes are usually used in parallel. This brings about a series of problems such as heat dissipation balance, installation complexity, current sharing, and drive circuit design. In terms of heat dissipation balance, parallel MOSFET tubes may cause uneven heat dissipation due to various factors, affecting the overall performance and life. In terms of installation complexity, the installation of a large number of single tubes is not only time-consuming and labor-intensive, but also manual operation is prone to assembly errors. In terms of current sharing, it is key to ensure that each MOSFET tube evenly shares the current, otherwise some tubes may be damaged due to overcurrent. In terms of drive circuit design, factors such as electromagnetic interference and signal integrity need to be considered to ensure the efficiency and reliability of the drive circuit.

[0005] Aluminum substrates also have certain limitations in high-power switching power supply applications. Since only one side of the aluminum substrate is a circuit layer, in high-power applications, each power MOSFET tube needs to be installed on the aluminum substrate, while other circuit components have to be installed on other circuit boards. This separate installation method not only increases the complexity of circuit design, but also introduces additional parasitic inductance and resistance through power line connections, which may affect the performance and stability of the circuit.

[0006] In summary, synchronous rectification technology has shown great application potential in the field of power conversion due to its high efficiency and low loss. However, in high-power switching power supply applications, how to balance the heat dissipation, installation, current sharing and drive design of power MOSFET tubes is an urgent problem to be solved. Summary of the invention

[0007] The first object of the present invention is to overcome the deficiencies of the prior art and provide a power rectification circuit structure for a multi-layer circuit board.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions: The power rectifier circuit structure of the multilayer circuit board includes an aluminum substrate, a first stack of plates and a second stack of plates, wherein n parallel power conversion circuits are arranged at equal intervals on the aluminum substrate, the first stack of plates is adapted to the power conversion circuit and is provided with a current limiting circuit, the second stack of plates is provided with a driving circuit, the first stack of plates is arranged above the aluminum substrate through a first pin, the second stack of plates is arranged above the first stack of plates through a second pin, and the driving circuit is connected to the driving end of the power conversion circuit through the current limiting circuit.

[0009] The present invention adopts a stacked design to integrate the first stacked plate and the second stacked plate onto the substrate, so that the first pin and the second pin play the role of connection and fixation as well as the role of signal transmission. At the same time, the power conversion circuits are all straight path circuits with equal intervals and lengths, which effectively avoids the problems of long and complex paths in traditional horizontal layouts. This design optimizes the layout, simplifies the design of the rectifier circuit, shortens the path of the rectifier circuit, and reduces unnecessary nodes. Compared with the prior art, the stacked design improves space utilization, makes the transmission of current and signals in the circuit more direct and efficient, reduces transmission time and loss, reduces temperature rise, enhances circuit reliability and stability, simplifies design complexity, and improves circuit integration and power density. This solution effectively solves the problem of difficult balance in heat dissipation, installation, current sharing and drive design of power MOSFET tubes in high-power switching power supply applications.

[0010] Furthermore, the aluminum substrate includes a wiring area, a component arrangement area and a power connection area, the wiring area is arranged in the middle of the aluminum substrate along its length direction, the power connection area is arranged on two opposite sides thereof, the component arrangement area is arranged between the wiring area and the power connection area, a MOSFET tube is arranged in the component arrangement area, and the current transmission ends of the MOSFET tubes in the two component arrangement areas are connected in series to form the power conversion circuit, the power conversion circuit is connected to an external power supply device through the power connection area on one side, and is connected to a load through the power connection area on the other side. This scheme is a specific design scheme for a power conversion circuit.

[0011] Furthermore, the first stacked plate is provided with n current limiting areas along the length direction, two groups of current limiting circuits are provided in the current limiting areas, and both sides of the current limiting areas are provided with outwardly protruding connecting parts, and the two groups of current limiting circuits are respectively connected to the power conversion circuit through the connecting parts on one side.

[0012] Furthermore, the MOSFET tube is a surface-mount MOSFET tube, so that a larger number of MOSFET tubes can be tightly arranged on the substrate, and the overall height of the aluminum substrate can be reduced to facilitate the installation of the first stack and the second stack, and to improve the stability of the power rectifier circuit structure.

[0013] Furthermore, the first stacked plate is provided with n current limiting regions along the length direction, two groups of current limiting circuits are provided in the current limiting regions, both sides of the current limiting regions are provided with outwardly protruding connection parts, and the two groups of current limiting circuits are respectively connected to the power conversion circuit through the connection parts on one side. In this scheme, the current limiting regions are arranged along the length direction of the first stacked plate, and the positions correspond to the n power conversion circuits one by one, and the power MOSFET tubes in the current limiting regions and on the corresponding two sides are provided with current limiting circuits.

[0014] Furthermore, the connecting portion is rectangular, and its upper surface and side surfaces are covered with a conductive layer. By adding a conductive layer, this solution can make it easier for solder to hang on the MOSFET tube pin and the PCB during welding, making welding simpler and faster, greatly reducing the technical requirements for welding workers, improving the contact reliability during welding, and reducing electrical connection problems caused by poor welding, thereby improving the reliability and stability of the entire electronic device.

[0015] Furthermore, the conductive layer is made by an immersion gold process. The immersion gold process of this solution can make full use of the uniform deposition characteristics of chemical gold plating to form a conductive layer on the side of the connecting part. Due to the small size of the connecting part and the irregular shape of the PCB board, it is difficult to form an effective conductive layer on its side by traditional processes, and the immersion gold process can effectively solve this problem.

[0016] Furthermore, the first stack of boards and the second stack of boards are double-sided printed circuit boards. This solution improves the wiring flexibility and integration of the circuit board, helps to optimize the circuit layout and reduce the size of the circuit board.

[0017] Furthermore, the current limiting circuit includes two current limiting resistors connected in parallel, and the current limiting resistors are chip resistors. This solution can reduce the overall height of the first stacked plate.

[0018] Furthermore, the first stack is provided with a first through hole for the first pin to pass through, a second through hole for the first pin to pass through, and a third through hole for the second pin to pass through on the second stack. During assembly, the first pin passes through the first through hole and the second through hole in sequence, and the second pin passes through the third through hole, protruding upward from the upper side of the second stack, the first stack abuts against the socket of the first pin, and the second stack abuts against the pin of the second pin, thereby achieving connection and fixation.

[0019] Another object of the present invention is to provide an assembling method of the above-mentioned power rectifier circuit structure, comprising the following steps: A power conversion circuit and a first plug pin are arranged on the aluminum substrate, including a conductive layer being arranged on the aluminum substrate, a wiring area being arranged in the middle, power connection areas being arranged on both sides, and a component arrangement area being arranged between the wiring area and the power connection area, a first plug pin is arranged in the wiring area, and a power MOSFET tube is arranged in the component arrangement area; a current limiting circuit is arranged on the first stack, including a plurality of current limiting areas, two groups of current limiting circuits are arranged in each current limiting circuit, and a second plug pin is arranged on the printed circuit board, one end of the current limiting circuit is electrically connected to the second plug pin, and a first via hole adapted to the first plug pin is opened; a drive circuit, a second via hole adapted to the first plug pin, and a third via hole adapted to the second plug pin are arranged on the second stack; the first stack is assembled on the upper side of the aluminum substrate, the connection part of the current limiting area is welded to the drive foot of the power MOSFET tube on the same side, the current limiting circuit is connected to the drive end of the power conversion circuit, and the second stack is assembled on the first stack, so that the drive circuit is electrically connected to the current limiting circuit through the second plug pin. This solution provides a detailed assembly method for the above-mentioned power rectifier circuit structure, and therefore has all the advantages of the above-mentioned solution, ensuring accurate and reliable assembly of the power rectifier circuit structure, and improving production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the overall schematic diagram of the power rectifier circuit structure; Figure 2 It is a structural decomposition diagram of the power rectifier circuit structure; Figure 3 is a schematic diagram of the layout of the substrate; Figure 4 This is the schematic diagram of the power rectifier circuit structure.

[0022] Description of labels: Substrate 1, wiring area 11, component arrangement area 12, power connection area 13, MOSFET tube 14, first laminate 2, connection part 21, second laminate 3, first pin 4, second pin 5. DETAILED DESCRIPTION

[0023] A preferred specific implementation of the present invention is described below with reference to the accompanying drawings.

[0024] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by “up”, “down”, “left”, “right”, “front”, “back”, “inside” and “outside”, etc., are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0025] Embodiment 1: The present embodiment discloses a power rectification circuit structure of a multilayer circuit board, including an aluminum substrate 1, a first laminate 2 and a second laminate 3, wherein n parallel power conversion circuits are arranged at equal intervals on the aluminum substrate 1, the first laminate 2 is adapted to the power conversion circuit and is provided with a current limiting circuit, the second laminate 3 is provided with a driving circuit, the first laminate 2 is arranged above the aluminum substrate 1 through a first pin 4, the second laminate 3 is arranged above the first laminate 2 through a second pin 5, and the driving circuit is connected to the driving end of the power conversion circuit through the current limiting circuit.

[0026] The specific design scheme of the above-mentioned power conversion circuit is as follows: the aluminum substrate 1 includes a wiring area 11, a component arrangement area 12 and a power connection area 13. The wiring area 11 is arranged in the middle of the aluminum substrate 1 along its length direction, and the power connection area 13 is arranged on two opposite sides thereof. The component arrangement area 12 is arranged between the wiring area 11 and the power connection area 13. A MOSFET tube 14 is arranged in the component arrangement area 12, and the current transmission ends of the MOSFET tubes 14 of the two component arrangement areas 12 are connected in series to form a power conversion circuit. The power conversion circuit is connected to an external power supply device through the power connection area 13 on one side, and is connected to a load through the power connection area 13 on the other side.

[0027] The first stacked plate 2 is provided with n current limiting areas along the length direction, and two groups of current limiting circuits are arranged in the current limiting areas. Both sides of the current limiting areas are provided with outwardly protruding connecting parts 21, and the two groups of current limiting circuits are respectively connected to the power conversion circuit through the connecting parts 21 on one side.

[0028] The above-mentioned MOSFET tube 14 is a surface-mount MOSFET tube 14, so that the substrate 1 can be tightly arranged with more MOSFET tubes 14, and the overall height of the aluminum substrate 1 can be reduced to facilitate the installation of the first stack 2 and the second stack 3, and improve the stability of the power rectifier circuit structure.

[0029] The first laminate 2 is provided with n current limiting regions along the length direction, two groups of current limiting circuits are provided in the current limiting regions, and both sides of the current limiting regions are provided with connecting parts 21 protruding outward, and the two groups of current limiting circuits are connected to the power conversion circuit through the connecting parts 21 on one side. In this solution, the current limiting regions are arranged along the length direction of the first laminate 2, and the positions correspond to the n power conversion circuits one by one, and the power MOSFET tubes 14 on both sides of the current limiting regions are provided with current limiting circuits.

[0030] The connecting portion 21 is rectangular, and its upper surface and side surfaces are covered with a conductive layer. By adding a conductive layer, this solution can make it easier to solder on the pins of the MOSFET tube 14 and the PCB during welding, making welding simpler and faster, greatly reducing the technical requirements for welding workers, improving the contact reliability during welding, and reducing electrical connection problems caused by poor welding, thereby improving the reliability and stability of the entire electronic device.

[0031] The above conductive layer is made by the immersion gold process. The immersion gold process of this solution can make full use of the uniform deposition characteristics of chemical gold plating to form a conductive layer on the side of the connecting portion 21. The problem of difficulty in forming an effective conductive layer on the side of the connecting portion 21 due to the small size of the connecting portion 21 and the irregular overall shape of the PCB board is avoided.

[0032] The first laminate 2 and the second laminate 3 are double-sided printed circuit boards.

[0033] The above-mentioned current limiting circuit includes two current limiting resistors connected in parallel, and the current limiting resistors are chip resistors. This solution can reduce the overall height of the first stacked plate 2.

[0034] The first laminate 2 is provided with a first via hole for the first pin 4 to pass through, the second laminate 3 is provided with a second via hole for the first pin 4 to pass through, and a third via hole for the second pin 5 to pass through.

[0035] The present invention adopts a stacked design to integrate the first stacked plate 2 and the second stacked plate 3 onto the substrate 1, so that the first pin 4 and the second pin 5 play the role of connection and fixation as well as the role of signal transmission. At the same time, the power conversion circuits are all straight path circuits with equal intervals and lengths, which effectively avoids the problems of long and complex paths in traditional horizontal layouts. This design optimizes the layout, simplifies the design of the rectifier circuit, shortens the path of the rectifier circuit, and reduces unnecessary nodes. Compared with the prior art, the stacked design improves space utilization, makes the transmission of current and signals in the circuit more direct and efficient, reduces transmission time and loss, reduces temperature rise, enhances circuit reliability and stability, simplifies design complexity, and improves circuit integration and power density. This solution effectively solves the problem of difficulty in balancing heat dissipation, installation, current sharing and drive design of the power MOSFET tube 14 in high-power switching power supply applications.

[0036] Embodiment 2: The present embodiment discloses an assembly method of the above-mentioned power rectifier circuit structure, comprising the following steps: arranging a power conversion circuit and a first pin 4 on an aluminum substrate 1, comprising arranging a conductive layer on the aluminum substrate 1, setting a wiring area 11 in the middle, setting power connection areas 13 on both sides, and setting a component arrangement area 12 between the wiring area 11 and the power connection area 13, arranging the first pin 4 in the wiring area 11, and arranging a power MOSFET tube 14 in the component arrangement area 12; arranging a current limiting circuit on the first stack 2, comprising arranging a plurality of current limiting areas, arranging two groups of current limiting circuits in each current limiting circuit, and arranging a current limiting circuit on the printed circuit board 2; A second pin 5 is arranged on the circuit board, so that one end of the current limiting circuit is electrically connected to the second pin 5, and a first via hole adapted to the first pin 4 is opened; a driving circuit, a second via hole adapted to the first pin 4, and a third via hole adapted to the second pin 5 are arranged on the second laminate 3; the first laminate 2 is assembled on the upper side of the aluminum substrate 1, and the connecting part of the current limiting area is welded to the driving foot of the power MOSFET tube 14 on the same side to connect the current limiting circuit to the driving end of the power conversion circuit; the second laminate 3 is assembled on the first laminate 2, so that the driving circuit is electrically connected to the current limiting circuit through the second pin 5.

[0037] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A power rectifier circuit structure of a multi-layer circuit board, characterized in that: It includes an aluminum substrate, a first stack of plates and a second stack of plates, wherein n parallel power conversion circuits are arranged at equal intervals on the aluminum substrate, the first stack of plates is adapted to the power conversion circuit and is provided with a current limiting circuit, the second stack of plates is provided with a driving circuit, the first stack of plates is arranged above the aluminum substrate through a first pin, the second stack of plates is arranged above the first stack of plates through a second pin, and the driving circuit is connected to the driving end of the power conversion circuit through the current limiting circuit.

2. The power rectifier circuit structure according to claim 1, characterized in that: The aluminum substrate includes a wiring area, a component arrangement area and a power connection area. The wiring area is arranged in the middle of the aluminum substrate along its length direction, the power connection area is arranged on two opposite sides thereof, the component arrangement area is arranged between the wiring area and the power connection area, a MOSFET tube is arranged in the component arrangement area, and the current transmission ends of the MOSFET tubes in the two component arrangement areas are connected in series to form the power conversion circuit. The power conversion circuit is connected to an external power supply device through the power connection area on one side, and is connected to a load through the power connection area on the other side.

3. The power rectifier circuit structure according to claim 2, characterized in that: The MOSFET tube is a surface-mount MOSFET tube.

4. The power rectifier circuit structure according to claim 1, characterized in that: The first stacked plate is provided with n current limiting areas along the length direction, two groups of current limiting circuits are arranged in the current limiting areas, and both sides of the current limiting areas are provided with connecting parts protruding outwards, and the two groups of current limiting circuits are respectively connected to the power conversion circuit through the connecting parts on one side.

5. The power rectifier circuit structure according to claim 4, characterized in that: The connecting portion is rectangular, and the upper surface and side surfaces thereof are covered with a conductive layer.

6. The power rectifier circuit structure according to claim 5, characterized in that: The conductive layer is made by using an immersion gold process.

7. The power rectifier circuit structure according to claim 1, characterized in that: The first stack of boards and the second stack of boards are double-sided printed circuit boards.

8. The power rectifier circuit structure according to claim 5, characterized in that: The current limiting circuit includes two current limiting resistors connected in parallel, and the current limiting resistors are chip resistors.

9. The power rectifier circuit structure according to claim 1, characterized in that: The first stack of boards is provided with a first via hole for the first pin to pass through, the second stack of boards is provided with a second via hole for the first pin to pass through, and a third via hole for the second pin to pass through.

10. An assembly method, characterized in that: The following steps are involved: Arranging the power conversion circuit and the first pin on the aluminum substrate, including arranging a conductive layer on the aluminum substrate, setting the middle part as a wiring area, setting the two sides as power connection areas, and setting the component arrangement area between the wiring area and the power connection area, arranging the first pin in the wiring area, and arranging the power MOSFET tube in the component arrangement area; Arranging a current limiting circuit on the first stacked board, including arranging a plurality of current limiting areas, arranging two sets of current limiting circuits on each current limiting circuit, arranging a second pin on the printed circuit board, making one end of the current limiting circuit electrically connected to the second pin, and opening a first via hole adapted to the first pin; A driving circuit, a second via hole adapted to the first pin, and a third via hole adapted to the second pin are arranged on the second stacked board; The first stack is assembled on the upper side of the aluminum substrate, and the connection part of the current limiting area is welded to the driving foot of the power MOSFET tube on the same side to connect the current limiting circuit to the driving end of the power conversion circuit. The second stack is assembled on the first stack to electrically connect the driving circuit to the current limiting circuit through the second pin.

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