PCB layout optimization method for vehicle thermal management system

Abstract

The embodiment of the invention provides a PCB layout optimization method for a finished automobile thermal management system, and relates to the technical field of automobile electronics and electricis.The method comprises the steps that firstly, electronic elements are subjected to electromagnetic interference analysis and grouped according to the electromagnetic interference degree, PCB layout planning is conducted according to the grouping result, and the rough area of each element group on a PCB is determined; detailed component layout is carried out according to the plan, and the orientation and spacing of the components are adjusted according to the electromagnetic radiation characteristics of the components and the layout condition of the surrounding components. Thirdly, during wiring design, not only the length of the line is considered to avoid bending and crossing, but also the line is arranged in the wiring corridor to reduce crossing and coupling; for differential wire pairs, adjacent parallel wiring is adopted to keep tight coupling between the wire pairs, and electromagnetic radiation is reduced. And finally, verifying the effectiveness of the PCB design and adjusting according to requirements until the verification is passed. The PCB layout of the whole vehicle thermal management system is comprehensively optimized, the electromagnetic interference can be effectively reduced, and the system performance is improved.

Description

[Technical field]

[0001] The embodiments of the present application relate to the field of automotive electronic and electrical technology, and in particular to a method for optimizing the PCB layout of a vehicle thermal management system. [Background technology]

[0002] At present, in modern automobiles, the vehicle thermal management system plays a key role. It is mainly used to control the temperature of various parts of the vehicle, ensure the normal operation of the vehicle under various working conditions, and improve the endurance of new energy vehicles. With the continuous improvement of the level of automobile electronics, the number of electronic components in the vehicle thermal management system continues to increase, and the problem of electromagnetic interference between components has become more and more prominent. Electromagnetic interference not only affects the normal operation of the vehicle thermal management system, but also has a negative impact on the reliability and safety of the vehicle. [Summary of the invention]

[0003] The embodiment of the present application proposes a PCB layout optimization method for a whole vehicle thermal management system, which relates to the field of automotive electronic and electrical technology. It mainly solves the problems existing in the prior art in layout planning and wiring design, and can improve the anti-interference ability of the whole vehicle thermal management system to ensure its normal operation and reliability.

[0004] The present application embodiment provides a method for optimizing the PCB layout of a vehicle thermal management system, the method comprising:

[0005] Perform electromagnetic interference analysis on the components on the thermal management system PCB and group them, where components with greater mutual interference are grouped into the same group;

[0006] Carry out PCB layout planning based on component grouping results;

[0007] Component placement based on layout planning, including: placing components in the same group on the same layer or using stacked placement, and adjusting component orientation and spacing between components based on the electromagnetic radiation characteristics of the components and the placement of surrounding components;

[0008] Design wiring according to the components to be laid out, including: planning wiring corridors to avoid line crossing, adjacent parallel wiring of differential pairs, and setting shielding layers in preset key wiring areas;

[0009] Verify the PCB with completed component placement and wiring design.

[0010] In at least one possible implementation, performing electromagnetic interference analysis and grouping includes:

[0011] Obtain electromagnetic interference data between components through simulation or actual measurement;

[0012] Using the electromagnetic interference data, establishing a component electromagnetic interference matrix;

[0013] Cluster analysis is performed on the component electromagnetic interference matrix to obtain several component groups.

[0014] In at least one possible implementation manner, establishing the component electromagnetic interference matrix includes generating the following matrix form based on at least the electromagnetic field strength and coupling coefficient between the components: each element in the matrix represents the degree of electromagnetic interference between two components.

[0015] In at least one possible implementation, obtaining a plurality of component groups includes aggregating the components into a plurality of groups based on the degree of interference based on a hierarchical clustering algorithm and the degree of electromagnetic interference between the components, specifically: calculating the interference similarity between each pair of components in the matrix, and gradually merging them into interference groups according to the similarity until a preset number of groups or a similarity threshold is reached.

[0016] In at least one possible implementation, the PCB layout planning includes:

[0017] Divide the PCB into layout areas corresponding to the number of component groups;

[0018] Determine the position of each corresponding area on the PCB board according to the component group: place multiple high-interference groups with larger electromagnetic interference in areas with farther group spacing, and arrange multiple low-interference groups with smaller electromagnetic interference close to each other.

[0019] In at least one possible implementation manner, the PCB layout planning further includes: separating high-power components through different layout areas.

[0020] In at least one possible implementation, the component layout includes:

[0021] Prioritize and lock the position of the first type of components that are limited by mechanical constraints or size;

[0022] Centrally place second-class components that connect to multiple other components.

[0023] In at least one possible implementation manner, the component layout method further includes: reducing the number of cross-networks formed by the components, and performing layer transition at the intersection of each network through a via.

[0024] In at least one possible implementation manner, the performing wiring design further includes: defining a trace width and adding a shielding layer in a preset wiring area.

[0025] In at least one possible implementation, defining the trace width is based on at least one of the following conditions: manufacturability, current carrying, and impedance.

[0026] The technical effects of the above scheme can be referred to as follows: By grouping components through component interference analysis, the electromagnetic interference problems existing in the thermal management system of the whole vehicle can be accurately identified, and the components can be grouped according to the degree of interference, so that the layout planning can be carried out in a targeted manner, and the component groups with greater mutual interference are kept as far away as possible, so as to reduce the occurrence of electromagnetic interference and improve the stability and reliability of the thermal management system of the whole vehicle. In addition, by optimizing the orientation of the components, the interference to other components is reduced; by adjusting the spacing between components, the possibility of electromagnetic interference is reduced, which can improve the anti-interference ability of the thermal management system of the whole vehicle and reduce the probability of failure. After that, through the planning of wiring corridors and differential pairs, the line length can be shortened, unnecessary bends and crossings can be reduced, and the electromagnetic coupling and interference between the lines can be reduced. Preferably, it is proposed that by setting a shielding layer, the signal line can be protected from external interference and the electromagnetic radiation to the outside world can be reduced. By the above design method, the signal transmission quality of the thermal management system of the whole vehicle can be improved, and the stability and reliability of the system can be improved.

Brief Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic flow chart of a method for optimizing the PCB layout of a vehicle thermal management system provided in an embodiment of the present application. [Specific implementation method]

[0029] In order to better understand the technical solution of this specification, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0030] It should be clear that the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0031] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit this specification. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0032] After analysis, the existing solutions to the electromagnetic problems of the PCB of the vehicle thermal management system still have shortcomings. First, the existing technology often lacks systematic analysis methods and guiding principles, resulting in a lack of clear guidance in the actual layout. Secondly, the existing technology lacks detailed methods and steps in PCB layout planning and detailed layout, and cannot effectively reduce the electromagnetic interference between components. In addition, the existing technology also has defects in wiring design, such as lack of guidance on wiring corridor planning and differential line pair wiring.

[0033] In view of this, the embodiment of the present application provides a method for optimizing the PCB layout of a vehicle thermal management system. The method groups components through component interference analysis, can accurately identify the electromagnetic interference problems existing in the vehicle thermal management system, and group the components according to the degree of interference, so that the layout planning can be carried out in a targeted manner, and the component groups with greater mutual interference are kept as far away as possible, so as to reduce the occurrence of electromagnetic interference and improve the stability and reliability of the vehicle thermal management system. In addition, by optimizing the orientation of the components, the interference to other components is reduced; by adjusting the spacing between the components, the possibility of electromagnetic interference is reduced, so that the anti-interference ability of the vehicle thermal management system can be improved and the probability of failure can be reduced. Afterwards, through the planning of wiring corridors and differential pairs, the line length can be shortened, unnecessary bends and crossovers can be reduced, and the electromagnetic coupling and interference between the lines can be reduced. Preferably, it is proposed that by setting a shielding layer, the signal line can be protected from external interference and the electromagnetic radiation to the outside world can be reduced. By the above-mentioned design method, the signal transmission quality of the vehicle thermal management system can be improved, and the stability and reliability of the system can be improved.

[0034] The technical solution protected by the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0035] See also Figure 1 , is a flow chart of a vehicle thermal management system PCB layout optimization method provided in an embodiment of the present application. The flow of the method is described as follows:

[0036] Step 101: Perform electromagnetic interference analysis on PCB components involved in the thermal management system and group them.

[0037] Specifically, the following steps can be included: (1) Obtaining electromagnetic interference data between components through simulation or actual measurement.

[0038] For example, in actual operation, you can choose professional electromagnetic simulation software tools in the industry, such as HFSS (High Frequency Structure Simulator) for electromagnetic interference simulation, import the three-dimensional models of all electronic components involved in the vehicle thermal management system into the simulation environment, and then set the simulation conditions according to the operating frequency, operating voltage and other parameters of the components, and simulate the electromagnetic field distribution and electromagnetic radiation between the components.

[0039] (2) Using the electromagnetic interference data, a component electromagnetic interference matrix is ​​established.

[0040] The electromagnetic interference data between all components are obtained in the above manner, including the electromagnetic field strength and coupling coefficient between the components, and then these data are organized into a matrix form, namely the component electromagnetic interference matrix. In some examples, each element in the matrix represents the degree of electromagnetic interference between two components, and the larger the value, the stronger the interference.

[0041] (3) Perform cluster analysis on the component electromagnetic interference matrix to obtain several component groups.

[0042] In actual operation, a hierarchical clustering algorithm can be used to gradually aggregate the components into multiple groups based on the degree of interference according to the degree of electromagnetic interference between the components. Specifically, in the clustering process, the interference similarity between each pair of components in the matrix can be calculated first, and then gradually merged into interference groups based on the similarity until the preset number of groups or thresholds is reached. Through the above clustering analysis, the components are grouped according to the degree of interference to obtain multiple interference groups, and the components with greater mutual interference are divided into one group, and the components with less interference are divided into another group. Or it can be understood that the electromagnetic interference between the components within each group is higher, while the interference between groups is lower. The definition of greater and lesser interference can be determined based on a preset threshold value of the degree of electromagnetic interference.

[0043] Step 102: Perform PCB layout planning based on the component grouping results.

[0044] In this step, refer to the component grouping results obtained by the hierarchical clustering algorithm. These groups are based on the degree of electromagnetic interference between components. Components with greater mutual interference are grouped into the same group. Therefore, the layout planning of the PCB board can be carried out based on these grouping results. The planning goal is to ensure that each component group can be properly placed while minimizing the electromagnetic interference between different groups.

[0045] From this, we can expand on the fact that first, layout areas corresponding to the number of component groups are divided on the PCB board. The size and shape of these areas will be adjusted according to the specific component groups and the shape of the PCB board to ensure maximum space utilization efficiency. Then, the position of each corresponding area on the PCB board is determined according to the component group. For example, for multiple high-interference groups with large electromagnetic interference, they can be placed in areas far apart to reduce the mutual influence between them; at the same time, the layout requirements of these high-interference groups can also be considered, such as the possibility of requiring a larger space or a specific layout direction. For low-interference groups with small electromagnetic interference, they can be appropriately arranged close to each other, which can not only save space, but also improve the overall layout efficiency of the PCB board. Of course, the special layout requirements of these low-interference groups will also be considered in some other embodiments, which will not be repeated here.

[0046] In addition, when planning the layout, you can also separate high-power components (the so-called high power can be defined according to the heat generation threshold). That is, the planning process also includes separating the components that emit a lot of heat on the PCB and placing them in different areas. The purpose of separating these high-power components is to balance the temperature around the PCB layout, rather than creating large hot spots in the layout and concentrating high-temperature components together. To achieve this goal, specifically, you can first look up the "thermal resistance" rating in the component datasheet and calculate the temperature rise based on the estimated heat dissipation, then optimize the copper design, and if necessary, add heat sinks and fans to reduce component temperatures.

[0047] Step 103: Arrange components based on the layout plan, including: placing components in the same component group on the same layer or using stacked layout, and adjusting component orientation and spacing between components according to the electromagnetic radiation characteristics of the components and the layout of surrounding components.

[0048] When actually laying out components, you can place the necessary components first, and usually some components must be placed in specific locations, mainly due to mechanical housing constraints or due to size, so give priority to placing and locking the positions of such components. Then, you can focus on placing components such as large processors and high-pin-count ICs, which usually need to be connected to multiple other components in the design. Placing these components together can make it easier to route traces in the PCB layout. It is worth noting that when laying out components in detail, it is better to avoid crossing networks as much as possible: unrouted networks are usually visible, and the number of crossing networks is minimized. Each network intersection can be layered through vias to avoid network intersections.

[0049] Step 104: Perform wiring design according to the laid out components, including: planning wiring corridors to avoid line crossings, and performing adjacent parallel wiring for differential line pairs.

[0050] When implementing wiring design, the goal is to minimize the line length and avoid unnecessary line bends and crossings. In this way, the electromagnetic coupling and interference between lines can be significantly reduced. There are two main aspects. First, in order to ensure the neatness and order of wiring, special wiring corridors can be planned on the PCB board. The role of these corridors is to provide a clear path for wiring and ensure that the wiring is carried out within the corridor, thereby effectively reducing the crossing and electromagnetic coupling between wiring. Second, for differential line pairs that need to transmit high-speed signals, it is proposed to adopt adjacent parallel wiring. It can ensure close coupling between line pairs, thereby reducing electromagnetic radiation and ensuring stable signal transmission.

[0051] In addition, it can be added that when designing the wiring, it also includes: defining the trace width and adding a shielding layer in the preset wiring area. To expand on this, for the trace width:

[0052] 1. Manufacturability needs to be considered: the trace cannot be too thin, otherwise reliable manufacturing cannot be achieved. In most cases, the trace width used will be much larger than the minimum value that the manufacturer can produce.

[0053] 2. Current needs to be considered: The current carried in the trace will determine the minimum width required for the trace to overheat. When the current is higher, the trace will also need to be wider.

[0054] 3. Impedance needs to be considered: High-speed digital signals or RF signals require a specific trace width to achieve the desired impedance value. This does not apply to all signals or networks, so there is no need to implement impedance control for each network in the circuit board design rules.

[0055] In order to further enhance the anti-interference ability of the wiring, a shielding layer is set in the preset key wiring area, which can effectively protect the signal line from external interference and reduce the electromagnetic radiation of the signal line to the outside world.

[0056] Step 105: Verify the PCB with completed component placement and wiring design.

[0057] In actual operation, the effectiveness of the preceding steps can be verified through electromagnetic simulation software or actual testing, and if the verification results do not meet the requirements, the component layout and wiring can be adjusted and optimized as needed until the performance reaches the verification standard.

[0058] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A method for optimizing the PCB layout of a vehicle thermal management system, characterized in that: The layout optimization method comprises: Perform electromagnetic interference analysis on the components on the thermal management system PCB and group them, where components with greater mutual interference are grouped into the same group; Carry out PCB layout planning based on component grouping results; Component placement based on layout planning, including: placing components in the same group on the same layer or using stacked placement, and adjusting component orientation and spacing between components based on the electromagnetic radiation characteristics of the components and the placement of surrounding components; Design wiring according to the components to be laid out, including: planning wiring corridors to avoid line crossing, adjacent parallel wiring of differential pairs, and setting shielding layers in preset key wiring areas; Verify the PCB with completed component placement and wiring design.

2. The vehicle thermal management system PCB layout optimization method according to claim 1 is characterized in that: The electromagnetic interference analysis and grouping comprises: Obtain electromagnetic interference data between components through simulation or actual measurement; Using the electromagnetic interference data, establishing a component electromagnetic interference matrix; Cluster analysis is performed on the component electromagnetic interference matrix to obtain several component groups.

3. The vehicle thermal management system PCB layout optimization method according to claim 2 is characterized in that: The establishing of the component electromagnetic interference matrix includes generating the following matrix form based at least on the electromagnetic field strength and coupling coefficient between the components: each element in the matrix represents the degree of electromagnetic interference between two components.

4. The vehicle thermal management system PCB layout optimization method according to claim 2 is characterized in that: The method of obtaining several component groups includes aggregating the components into multiple groups based on the degree of interference based on a hierarchical clustering algorithm and the degree of electromagnetic interference between the components. Specifically, the interference similarity between each pair of components in the matrix is ​​calculated, and the components are gradually merged into interference groups according to the similarity until a preset number of groups or a similarity threshold is reached.

5. The vehicle thermal management system PCB layout optimization method according to claim 1 is characterized in that: The PCB layout planning includes: Divide the PCB into layout areas corresponding to the number of component groups; Determine the position of each corresponding area on the PCB board according to the component group: place multiple high-interference groups with larger electromagnetic interference in areas with farther group spacing, and arrange multiple low-interference groups with smaller electromagnetic interference close to each other.

6. The vehicle thermal management system PCB layout optimization method according to claim 5 is characterized in that: The PCB layout planning also includes: separating high power components through different layout areas.

7. The vehicle thermal management system PCB layout optimization method according to claim 1 is characterized in that: Component layout methods include: Prioritize and lock the position of the first type of components that are limited by mechanical constraints or size; Centrally place second-class components that connect to multiple other components.

8. The vehicle thermal management system PCB layout optimization method according to claim 1 is characterized in that: The component layout method also includes: reducing the number of cross-networks formed by components, and performing layer transition at the intersection of each network through vias.

9. The method for optimizing the PCB layout of a vehicle thermal management system according to any one of claims 1 to 8, characterized in that: The wiring design also includes: defining the trace width and adding a shielding layer in a preset wiring area.

10. The vehicle thermal management system PCB layout optimization method according to claim 9, characterized in that: Defining the trace width is based on at least one of the following criteria: manufacturability, current carried, and impedance.

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