A power drive board structure suitable for large-current current-sharing and bus connection

Abstract

The utility model discloses a kind of power drive board structures suitable for large current current-sharing, including the printed circuit board of surface copper foil thickness not more than 35 μm, several groups of power device groups and terminal block group welded on it, and several rectangular sheet copper bars welded between same network power device group and terminal block group. The copper bar is closely attached to the large current pin of power device and the pin of terminal, and the spacing with the pin of power device is not more than 0.7mm, and the spacing with the pin of terminal is not more than 2.0mm, and the thickness is 1-3mm. The utility model provides low impedance, consistent current path through copper bar, effectively solve the problem of uneven current distribution and ground level fluctuation caused by wiring impedance of traditional PCB, with the advantages of good current-sharing performance, high reliability, simple structure, low cost and the like.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, specifically to a power drive board structure suitable for high current and high current sharing requirements. Background Technology

[0002] In power electronic equipment, power drive boards are commonly used to drive motors, loads, and other applications requiring high current. Ordinary printed circuit boards (PCBs) typically carry high currents by widening copper traces or using large copper areas. However, this approach has a significant drawback: when the current path is long or the components are distributed widely, the impedance of the PCB traces themselves can cause inconsistent voltage drops across components at different points, resulting in uneven current distribution (i.e., poor current sharing). This current unevenness not only reduces system efficiency and causes localized overheating, but can also distort the current sampling signal due to voltage level differences at different points on the ground plane (GND), thus affecting the control accuracy and reliability of the entire system.

[0003] Another solution is to use large copper busbars directly as terminals and weld them together. While this can improve current carrying capacity, such large copper busbars are expensive, have inflexible layouts, occupy a lot of space, and increase overall cost and structural design difficulty.

[0004] Therefore, there is an urgent need for a new power driver board structure to solve the current sharing and merging problems in high-current scenarios in a low-cost and highly reliable manner. Utility Model Content

[0005] The purpose of this invention is to address the problems in the existing technology, such as poor current sharing effect and ground level fluctuation caused by inconsistent impedance of the high current path in PCBs, as well as high cost and inflexible layout due to the use of large-area copper busbars. It provides a power drive board structure that is simple in structure, low in cost, and highly reliable, and achieves excellent high current sharing and current merging performance by optimizing the current path.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A power drive board structure suitable for high current sharing and busbar configuration includes: The thickness of the copper foil on the surface of the printed circuit board is no more than 35μm; Several groups of power devices are soldered onto the printed circuit board. Each group of power devices includes power devices of the same specification arranged in a row. The power devices have high-current pins on the same network. Several sets of terminal blocks are soldered onto the printed circuit board, and each set of terminal blocks includes multiple terminals on the same network. Several copper busbars, which are rectangular sheet structures, are soldered onto the copper foil of the printed circuit board and are arranged between the power device group and the terminal block group in the same network, and are arranged in close contact with the high current pins of the power devices and the pins of the terminals. The copper busbar is a single integrated structure, or it is composed of multiple standard copper busbar plates arranged longitudinally and closely attached to each other in parallel.

[0007] Furthermore, the distance between the copper busbar and the high-current pin of the power device is no greater than 0.7 mm.

[0008] Furthermore, the distance between the copper busbar and the pin of the terminal block is no greater than 2.0 mm.

[0009] Furthermore, the thickness of the copper busbar is 1mm to 3mm.

[0010] Furthermore, the power device includes at least one of a surface-mount MOSFET and a sampling resistor.

[0011] Furthermore, the width of the copper busbar is not less than the width of the high-current pin of the power device.

[0012] Furthermore, the length of the copper busbar covers the high-current pins of all power devices in the same group.

[0013] Furthermore, when the copper busbar is composed of multiple copper busbar pieces connected in parallel, each copper busbar piece has the same size.

[0014] Furthermore, at least one terminal in the terminal block assembly is a high-power locking terminal, which includes: The locking part located at the upper end is used to secure the external cable; Multiple through-hole pins located at the lower end are used for soldering to the printed circuit board.

[0015] Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: 1. Excellent current sharing performance: By directly soldering a thick copper busbar between the power device pins and terminals, an ideal path with low impedance and low inductance is provided for large currents, fundamentally reducing the problem of uneven current distribution caused by path impedance differences.

[0016] 2. Low cost: The copper busbar used in this utility model is a small rectangular sheet structure. Compared with the large copper busbar used as a terminal block, the material usage is greatly reduced and the cost is significantly reduced.

[0017] 3. Improved system reliability: Stable current distribution reduces the generation of local hot spots, lowering the risk of device overheating and damage. Simultaneously, a stable ground level ensures the accuracy of the sampling signal, improving the overall control precision and reliability of the system.

[0018] 4. Simple structure and easy to implement: This structure can be achieved by simply adding a copper busbar welding process to the existing PCB process. No complicated process modifications are required, resulting in low cost and easy mass production.

[0019] 5. High material versatility and lower cost: This invention allows the use of multiple standard-sized copper busbars connected in parallel to replace a single integrated copper busbar. This design greatly reduces the number of copper busbar specifications required to accommodate different current capacities, simplifies material management, reduces procurement costs and inventory pressure, while maintaining excellent electrical performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall layout of the power drive board structure of this utility model. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] See Figure 1 The power drive board structure of this utility model mainly includes a PCB 1, a power device group 2, a terminal block group 3, and a copper busbar 4.

[0023] PCB 1 uses standard FR-4 material, but the copper foil on its surface used to carry high current is relatively thin, not exceeding 35μm. Multiple groups of power devices 2 and a row of multiple power devices of the same specification (such as surface-mount MOSFETs 21 and sampling resistors 22) are soldered onto PCB 1. The source, drain, or resistor leads of these power devices are the "high-current leads" that need to carry high current, and they belong to the same electrical network through the copper foil layout inside the PCB.

[0024] Terminal block 3 is also soldered onto PCB 1, and its pins belong to the same network (such as power or ground network) as the high-current pins of power device block 2.

[0025] Furthermore, the terminal block 3 includes at least one high-power locking terminal 31 for connecting or disconnecting high current from the main circuit. The upper end of this high-power locking terminal 31 has a locking portion, such as a screw-press structure, for reliably fixing and connecting external large-section cables; its lower end has multiple parallel, straight-insertion pins that are directly inserted into and soldered into the pad holes of the PCB 1. This multi-pin structure greatly enhances the mechanical fixing strength of the terminal on the PCB, can withstand the stress during cable insertion and removal, and provides a larger current conduction area and a better heat dissipation path.

[0026] To achieve low-impedance connection, the key to this invention lies in the use of an integral copper busbar 4, or a copper busbar assembly composed of multiple longitudinally arranged and closely connected standard-sized copper busbar sheets 41 connected in parallel. The total thickness of the copper busbar or copper busbar assembly is preferably 1mm to 3mm, and it is directly soldered onto the copper foil of the PCB 1 by SMT (Surface Mount Technology) or manual soldering.

[0027] Preferably, when multiple copper busbars are combined, these copper busbars have the same length, width, and thickness. In production, a few standard sizes of copper busbars can be pre-fabricated, and then, according to different current rating requirements, different numbers of copper busbars can be stacked to flexibly achieve the required current carrying capacity and structural strength, thereby avoiding the high cost and long lead time of customizing dedicated copper busbars for each product.

[0028] One end of copper busbar 4 is placed close to the high-current pin of the power device (such as MOSFET 21), with the distance between them controlled within 0.7mm to ensure extremely low connection impedance and good soldering strength. The other end of copper busbar 4 is placed close to the pin of the terminal block 3, with the distance between them controlled within 2.0mm.

[0029] Preferably, the length of the copper busbar 4 should be sufficient to cover the high-current pins of all power devices in the same group, thereby achieving an effective "bus".

[0030] This structure provides a superior current path than PCB traces through copper busbar 4, ensuring a highly consistent path impedance from each power device to the high-current terminals, thereby achieving excellent dynamic and static current sharing effects and solving many of the problems mentioned in the background art.

[0031] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A power drive board structure suitable for high current sharing and merging, characterized in that, include: The thickness of the copper foil on the surface of the printed circuit board is no more than 35μm; Several groups of power devices are soldered onto the printed circuit board. Each group of power devices includes power devices of the same specification arranged in a row. The power devices have high-current pins on the same network. Several sets of terminal blocks are soldered onto the printed circuit board, and each set of terminal blocks includes multiple terminals on the same network. Several copper busbars, which are rectangular sheet structures, are soldered onto the copper foil of the printed circuit board and are arranged between the power device group and the terminal block group in the same network, and are arranged in close contact with the high current pins of the power devices and the pins of the terminals. The copper busbar is a single integrated structure, or it is composed of multiple standard copper busbar plates arranged longitudinally and closely attached to each other in parallel.

2. The power drive board structure as described in claim 1, characterized in that, The distance between the copper busbar and the high-current pin of the power device is no greater than 0.7 mm.

3. The power drive board structure as described in claim 1, characterized in that, The distance between the copper busbar and the pin of the terminal block is no greater than 2.0 mm.

4. The power drive board structure as described in claim 1, characterized in that, The thickness of the copper busbar is 1mm to 3mm.

5. The power drive board structure as described in claim 1, characterized in that, The width of the copper busbar is not less than the width of the high-current pin of the power device.

6. The power drive board structure as described in claim 1, characterized in that, The length of the copper busbar covers the high-current pins of all power devices in the same group.

7. The power drive board structure as described in claim 1, characterized in that, When the copper busbar is composed of multiple copper busbar pieces connected in parallel, each copper busbar piece has the same size.

8. The power drive board structure as described in any one of claims 1-7, characterized in that, The power device includes at least one of a surface-mount MOSFET and a sampling resistor.

9. The power drive board structure as described in any one of claims 1-7, characterized in that, At least one terminal in the terminal block assembly is a high-power locking terminal, which includes: The locking part located at the upper end is used to secure the external cable; Multiple through-hole pins located at the lower end are used for soldering to the printed circuit board.

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