A Thermal Simulation Method, System and Medium for Printed Circuit Boards

Abstract

The present invention relates to the technical field of data simulation processing, and particularly to a thermal simulation method, system and medium for a circuit board. The method includes the following steps: obtaining circuit board layer data; extracting the thermal resistance parameters of the board layer materials of the circuit board layer data, including copper foil thermal resistance parameters and insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data and recording it as hierarchical structure data; determining the component layout characteristics according to the hierarchical structure data, and performing an interlayer thermal resistance distribution calculation on the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate layer structure thermal resistance distribution data. The present invention realizes the heat transfer interaction analysis of the copper foil layer and the insulating medium layer of the circuit board through data processing technology and simulation technology, and realizes the evaluation of the heat transfer direction and heat accumulation effect of the circuit board to construct a thermal simulation model of the circuit board.

Description

Technical Field

[0001] The present invention relates to the technical field of data simulation processing, and particularly to a thermal simulation method, system and medium for a circuit board. Background Technique

[0002] With the development of electronic devices towards miniaturization, high performance and high integration, the printed circuit board (PCB), as the core carrier of electronic devices, its thermal management problem has become increasingly important. In modern electronic products, the power of electronic components is continuously increasing, and at the same time, high-density packaging and assembly make the heat dissipation space smaller and smaller, resulting in a sharp increase in the heat flux density. If the heat cannot be effectively managed and dissipated, these heats may cause the performance of components to decline, the reliability to decrease, and even lead to equipment failure or damage; Traditional thermal simulation methods such as the finite element method (FEM) and the finite difference method (FDM) need to establish a high-precision grid model on the entire circuit board, especially in the complex multi-layer circuit board or the area around components. This not only requires a large amount of computing resources but also makes the simulation process very time-consuming. As the complexity of the circuit board increases, the demand for simulation time and computing resources rises sharply, and it is difficult for traditional methods to find a suitable balance between high precision and computational complexity; And for the different material layers inside the circuit board, especially the thermal transfer interaction analysis between the copper foil layer and the insulating dielectric layer is not accurate enough, and it is difficult to accurately evaluate the thermal transfer direction and the thermal accumulation effect. Summary of the Invention

[0003] Based on this, it is necessary to provide a thermal simulation method, system and medium for a circuit board to solve at least one of the above technical problems.

[0004] To achieve the above object, a thermal simulation method for a circuit board, the method includes the following steps:

[0005] Step S1: Obtain the circuit board layer data; extract the thermal resistance parameters of the board layer materials of the circuit board layer data, including the copper foil thermal resistance parameters and the insulating dielectric thermal resistance parameters; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data;

[0006] Step S2: Determine the component layout characteristics according to the hierarchical structure data, and calculate the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the layer structure thermal resistance distribution data;

[0007] Step S3: Calculate the joule heat value for the heat flux density distribution data based on the foil thermal resistance parameters and the insulating dielectric thermal resistance parameters; determine the thermal transfer interaction coefficient between the copper foil layer and the insulating dielectric layer through the joule heat value to obtain the circuit board thermal interaction data;

[0008] Step S4: Evaluate the changing trend of the operating temperature of the circuit board based on the circuit board thermal interaction data to generate temperature change trend data; perform a thermal accumulation effect simulation on the circuit board according to the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0009] By obtaining the circuit board layer data, the present invention can accurately extract the thermal resistance parameters of the copper foil and the thermal resistance parameters of the insulating medium, providing accurate basic data for subsequent thermal simulation calculations and ensuring the accuracy of subsequent thermal simulation analyses; identifying the hierarchical structure of the circuit board layer data and recording it as hierarchical structure data enables a clear understanding of the structural characteristics of the circuit board, providing a clear structural basis for subsequent component layout feature analysis and interlayer thermal resistance distribution calculation based on the hierarchical structure; after determining the component layout features according to the hierarchical structure data, calculating the interlayer thermal resistance distribution based on the thermal resistance parameters of the board layer material for this feature, the generated interlayer structure thermal resistance distribution data can accurately reflect the thermal resistance situation between the layers of the circuit board, providing a reliable thermal resistance distribution basis for the calculation of subsequent heat flux density distribution data; detecting the interlayer via wiring features based on the component layout features and calculating the heat flux density distribution data based on the interlayer structure thermal resistance distribution data can accurately simulate the heat flux density situation in each area of the circuit board during actual operation, providing accurate heat flux density information for subsequent joule heat value calculation; calculating the joule heat value based on the thermal resistance parameters of the copper foil and the thermal resistance parameters of the insulating medium for the heat flux density distribution data can accurately obtain the joule heat value generated by each part of the circuit board, providing accurate heat value data for subsequent determination of the heat transfer interaction coefficient; determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value, the obtained circuit board thermal interaction data can truly reflect the heat transfer situation between different material layers inside the circuit board, providing key thermal interaction information for subsequent evaluation of the changing trend of the operating temperature; evaluating the changing trend of the operating temperature of the circuit board based on the circuit board thermal interaction data, the generated temperature change trend data can accurately predict the temperature change situation of the circuit board under different operating conditions, providing an important reference basis for the thermal management and reliability evaluation of the circuit board; performing a thermal accumulation effect simulation on the circuit board according to the temperature change trend data and constructing a thermal simulation model of the circuit board, which can comprehensively and accurately simulate the thermal behavior of the circuit board during actual operation. Therefore, the present invention realizes the thermal transfer interaction analysis of the copper foil layer and the insulating medium layer of the circuit board through data processing technology and simulation technology, and realizes the evaluation of the thermal transfer direction and thermal accumulation effect of the circuit board to construct a thermal simulation model of the circuit board.

[0010] Preferably, step S1 includes the following steps:

[0011] Step S11: Obtain the structural parameters, material information, and connection point distribution information of the circuit board respectively to obtain the circuit board layer data;

[0012] Step S12: Identify the copper foil layer and the insulating dielectric layer from the circuit board layer data, mark the boundary positions between the copper foil layer and the insulating dielectric layer, and extract the thermal resistance parameters of the copper foil layer and the insulating dielectric layer to obtain the thermal resistance parameters of the board layer materials;

[0013] Step S13: Obtain the copper foil thermal resistance parameter and the insulating dielectric thermal resistance parameter of the thermal resistance parameters of the board layer materials respectively;

[0014] Step S14: Scan layer by layer from the circuit board layer data, determine the boundary range of each layer, and mark it as the start and end points of each layer; where the scanning speed is 10 layers per second, and the thickness accuracy of each layer is 0.001 mm;

[0015] Step S15: Number each layer, and record the layer numbers and the thicknesses of each layer in order from the outside to the inside;

[0016] Step S16: For two adjacent layers, determine whether there is a connection relationship between the two adjacent layers, and record the connection relationship of the adjacent layer positions;

[0017] Step S17: Integrate the start and end points of each layer, the layer numbers of each layer, the thicknesses of each layer, and the connection relationship of the adjacent layer positions into hierarchical structure data.

[0018] The present invention constructs the circuit board layer data completely by obtaining the structural parameters, material information, and connection point distribution information of the circuit board, providing comprehensive and accurate basic information for subsequent thermal simulation analysis, and ensuring that the thermal simulation process can be based on the complete circuit board characteristics; identifying the copper foil layer and the insulating dielectric layer in the circuit board layer data, marking the boundary positions and extracting the thermal resistance parameters, realizing the accurate distinction and parameter acquisition of different material layers, and providing a clear material boundary and accurate thermal resistance parameters for subsequent thermal resistance distribution calculation; obtaining the copper foil thermal resistance parameters and the insulating dielectric thermal resistance parameters respectively, ensuring the clear classification of the thermal resistance parameters, facilitating subsequent targeted thermal simulation analysis for different material layers, and improving the accuracy and pertinence of the thermal simulation calculation; scanning and marking the boundary ranges layer by layer at a speed of scanning 10 layers per second and with a thickness accuracy of 0.001 mm for each layer, realizing the efficient and high-precision identification of each layer of the circuit board, and ensuring the accuracy and reliability of the hierarchical structure data; numbering each layer and recording the layer numbers and thicknesses of each layer, sorting them in the order from the outside to the inside, and establishing a clear hierarchical structure order; judging the connection relationship between adjacent layers and recording the connection relationship of adjacent layer positions, clarifying the connection characteristics between layers, providing important connection information for subsequent analysis of interlayer heat transfer and heat flow distribution, and ensuring that the thermal simulation model can accurately reflect the structural characteristics of the actual circuit board; integrating the start and end points of each layer, the layer numbers of each layer, the thicknesses of each layer, and the connection relationship of adjacent layer positions into hierarchical structure data, forming a complete and systematic description of the hierarchical structure, providing a comprehensive and structured data basis for subsequent thermal simulation analysis based on the hierarchical structure, and ensuring that the thermal simulation process can be based on the accurate hierarchical structure.

[0019] Preferably, in step S2, determining the component layout characteristics according to the hierarchical structure data and performing the interlayer thermal resistance distribution calculation on the thermal resistance parameters of the board layer materials based on the component layout characteristics includes:

[0020] Determining the component information of each layer from the hierarchical structure data and identifying the boundary lines of the component information to obtain the component shape and size;

[0021] Numbering the coordinates of the component shape and size, and sequentially marking the positions of the components in the order from left to right and from top to bottom to generate the component position coordinates;

[0022] Determining the distance between adjacent components and the distance between the components and the circuit board edge according to the component position coordinates to obtain the component layout distance parameters;

[0023] Integrating the component shape and size, the component position coordinates, and the component layout distance parameters into the component layout characteristics;

[0024] Determine the thermal resistance contribution area of components on the circuit board according to the component layout characteristics, and calculate the thermal resistance values of the components in different board layers based on the thermal resistance contribution area of the components;

[0025] Between adjacent board layers, detect the thermal resistance coupling area according to the layout characteristics of the components; calculate the interlayer thermal resistance value of the coupling area between adjacent board layers based on the thermal resistance coupling area to obtain the thermal resistance distribution data of the layer structure.

[0026] The present invention determines the component information of each layer and identifies the boundary lines from the hierarchical structure data to obtain the component shape and size, which can accurately obtain the geometric features of the components, provide an accurate shape basis for subsequent layout analysis and thermal resistance calculation, and ensure that the thermal simulation model can truly reflect the physical form of the components; number the component shape and size by coordinates, mark the positions in the order from left to right and from top to bottom to generate the component position coordinates, realizing the accurate positioning of the components on the board, providing clear coordinate information for subsequent analysis of the relative position relationship between the components, and improving the accuracy of layout analysis; determine the distance between adjacent components and the distance between the components and the edge of the circuit board according to the component position coordinates to obtain the component layout distance parameters, which can quantify the spatial distribution relationship between the components, provide an important distance basis for subsequent evaluation of the thermal influence and thermal resistance distribution between the components, and ensure the accuracy of thermal simulation analysis; integrate the component shape and size, position coordinates and layout distance parameters into the component layout characteristics, forming a comprehensive and systematic description of the component layout, providing a complete and structured data basis for subsequent thermal resistance calculation and heat flow analysis based on the layout characteristics, and ensuring that the thermal simulation process can be carried out based on accurate layout information; determine the thermal resistance contribution area of the components on the circuit board according to the component layout characteristics and calculate its thermal resistance value in different board layers, which can accurately identify the influence range of the components on the thermal performance of the circuit board and quantify its thermal resistance contribution, providing key thermal resistance data for subsequent calculation of the heat flux density distribution and construction of the thermal simulation model, and improving the pertinence and accuracy of thermal simulation analysis; between adjacent board layers, detect the thermal resistance coupling area according to the component layout characteristics and calculate the interlayer thermal resistance value of the coupling area to obtain the thermal resistance distribution data of the layer structure, which can accurately simulate the thermal interaction between adjacent board layers, ensure that the thermal simulation model can truly reflect the interlayer heat transfer characteristics, and provide reliable interlayer thermal resistance information for the overall thermal performance evaluation of the circuit board.

[0027] Preferably, in step S2, detecting the interlayer via wiring characteristics according to the component layout characteristics and calculating the heat flux density distribution data based on the interlayer via wiring characteristics for the thermal resistance distribution data of the layer structure includes:

[0028] Determine the via requirements of the components in different board layers according to the component layout characteristics, and determine the hole position distribution coordinates according to the via requirements;

[0029] Detect the via setting conditions of the detection hole position distribution coordinates, including the aperture deviation amount and the via center offset degree;

[0030] Detect the vertical alignment of vias between different board layers according to the aperture deviation amount to obtain the via vertical alignment; Detect the offset amount of vias during interlayer penetration according to the via center offset degree to obtain the via interlayer offset amount;

[0031] Judge the interlayer via routing relationship based on the via vertical alignment and the via interlayer offset amount to generate the interlayer via routing characteristics;

[0032] Determine the via hole distribution density and the distance between holes according to the interlayer via routing characteristics;

[0033] Identify the board heat flow path of the circuit board based on the via hole distribution density and the distance between holes, and divide the board heat flow path into a heat flow convergence area and a heat flow dispersion area;

[0034] For the heat flow convergence area, calculate the increase multiple of the heat flow density of the circuit board according to the via hole distribution density, and record the peak value of the regional heat flow density;

[0035] For the heat flow dispersion area, calculate the heat flow uniformity coefficient of the circuit board according to the distance between holes, and record the regional heat flow uniformity coefficient;

[0036] Perform heat flow density distribution measurement on the layer structure thermal resistance distribution data based on the peak value of the regional heat flow density and the regional heat flow uniformity coefficient to generate heat flow density distribution data.

[0037] The present invention determines the via requirements of components on different board layers according to the component layout characteristics, and determines the via position distribution coordinates according to the via requirements, which can accurately identify the electrical connection requirements of components and clarify the specific positions of vias, providing accurate via position information for subsequent via routing feature analysis and ensuring the coordination between the electrical connection design and thermal simulation analysis of the circuit board; detecting the via setting conditions of the via position distribution coordinates, including the aperture deviation and the via center offset, can quantify the manufacturing accuracy problems of vias, providing key parameters for subsequent analysis of the influence of vias on the heat flow path and ensuring that the thermal simulation model can truly reflect the actual heat conduction characteristics of vias; detecting the vertical alignment of vias between different board layers according to the aperture deviation to obtain the via vertical alignment; detecting the offset of vias during interlayer penetration according to the via center offset to obtain the via interlayer offset, which can accurately evaluate the alignment of vias in a multi-layer circuit board, providing accurate alignment and offset data for subsequent judgment of the interlayer via routing relationship and ensuring the accuracy of thermal simulation analysis; judging the interlayer via routing relationship based on the via vertical alignment and the via interlayer offset to generate the interlayer via routing characteristics, which can comprehensively describe the connection state and heat conduction path of vias between layers, providing important routing feature information for subsequent heat flow path identification and heat flow density distribution calculation; determining the via distribution density and the distance between vias according to the interlayer via routing characteristics can quantify the layout characteristics of vias and ensure that the thermal simulation model can accurately reflect the influence of vias on heat flow; identifying the board heat flow path of the circuit board based on the via distribution density and the distance between vias and dividing the board heat flow path into a heat flow convergence area and a heat flow dispersion area can clarify the heat flow distribution characteristics on the circuit board; for the heat flow convergence area, calculating the heat flow density increase multiple of the circuit board according to the via distribution density and recording the peak value of the regional heat flow density can quantify the change of the heat flow density in the heat flow convergence area; for the heat flow dispersion area, calculating the heat flow uniformity coefficient of the circuit board according to the distance between vias and recording the regional heat flow uniformity coefficient can quantify the heat flow uniformity in the heat flow dispersion area; measuring the heat flow density distribution of the layer structure thermal resistance distribution data based on the peak value of the regional heat flow density and the regional heat flow uniformity coefficient can comprehensively reflect the heat flow density conditions in different regions of the circuit board.

[0038] Preferably, the calculation of the joule heat value for the heat flow density distribution data based on the foil thermal resistance parameter and the insulating medium thermal resistance parameter in step S3 includes:

[0039] Determining the corresponding regional areas for the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter respectively to obtain the copper foil thermal resistance regional area and the insulating medium thermal resistance regional area;

[0040] Calculating the area density ratio of the heat flow density distribution data based on the copper foil thermal resistance regional area and the insulating medium thermal resistance regional area to obtain the heat flow density area ratio value;

[0041] Calculate the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area respectively according to the ratio of the heat flux density area; and combine the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area to generate a joule heat value.

[0042] In the present invention, the corresponding area of the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter are respectively determined to obtain the copper foil thermal resistance area and the insulating medium thermal resistance area, which can clarify the distribution range of different materials in the heat flow path and provide an accurate area basis for the subsequent calculation of the heat flux density distribution; based on the copper foil thermal resistance area and the insulating medium thermal resistance area, the area density ratio of the heat flux density distribution data is calculated to obtain the ratio of the heat flux density area, which can quantify the contribution ratio of different regions to the heat flux density and provide key area ratio data for the subsequent calculation of the joule heat; calculate the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area respectively according to the ratio of the heat flux density area, and combine the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area to generate a joule heat value, which can comprehensively reflect the heat generation situation of the circuit board in different regions and provide accurate heat data for the overall thermal performance evaluation of the circuit board.

[0043] Preferably, the determination of the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value in step S3 includes:

[0044] Calculate the joule heat ratio of the copper foil layer and the insulating medium layer according to the joule heat value to obtain the thermal energy ratio of the two layers;

[0045] Based on the thermal energy ratio of the two layers, determine the heat transfer direction between the copper foil layer and the insulating medium layer to generate an interlayer heat transfer direction; if the thermal energy ratio of the two layers is greater than or equal to 1, the heat transfer direction is from the copper foil layer to the insulating medium layer; if the thermal energy ratio of the two layers is less than 1, the heat transfer direction is from the insulating medium layer to the copper foil layer;

[0046] Judge the heat transfer interaction coefficient through the interlayer heat transfer direction and record the circuit board layer information corresponding to the heat transfer interaction coefficient to obtain the circuit board heat interaction data.

[0047] The present invention calculates the ratio of the Joule heat of the copper foil layer to that of the insulating dielectric layer according to the Joule heat value, obtains the ratio of the thermal energies of the two layers, can quantify the heat distribution relationship between the copper foil layer and the insulating dielectric layer, and provides an accurate heat ratio basis for determining the subsequent heat transfer direction; determining the heat transfer direction between the copper foil layer and the insulating dielectric layer based on the ratio of the thermal energies of the two layers can clarify the heat transfer path between different material layers. When the ratio of the thermal energies of the two layers is greater than or equal to 1, the heat transfer direction is from the copper foil layer to the insulating dielectric layer; when the ratio of the thermal energies of the two layers is less than 1, the heat transfer direction is from the insulating dielectric layer to the copper foil layer. This result provides a clear directional basis for the judgment of the heat transfer interaction coefficient; judging the heat transfer interaction coefficient through the heat transfer direction and recording the circuit board layer information corresponding to the heat transfer interaction coefficient to obtain the circuit board heat interaction data can comprehensively reflect the heat transfer characteristics between different material layers inside the circuit board and provide key heat interaction parameters for the thermal simulation model of the circuit board.

[0048] Preferably, step S4 includes the following steps:

[0049] Step S41: Determine the interactive heat flux density value and the interactive temperature value of the circuit board heat interaction data;

[0050] Step S42: Extract the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and perform chronological division to form time series data;

[0051] Step S43: Perform differential processing on the time series data, calculate the change in heat flux density and the change in temperature between adjacent time points to obtain the heat flux density change rate and the temperature change rate, where the differential processing uses the five-point differential method and controls the error range within ±2%;

[0052] Step S44: Evaluate the change trend of the operating temperature of the circuit board according to the heat flux density change rate and the temperature change rate, and record the intensity value of the change trend of the operating temperature;

[0053] Step S45: When the intensity values of three consecutive time points are all greater than 0.1 °C / s and the increase rate of the intensity value exceeds 10%, it is determined as an upward trend; when the intensity values of three consecutive time points are all less than -0.1 °C / s and the decrease rate of the intensity value exceeds 10%, it is determined as a downward trend; when the intensity values of three consecutive time points are all less than 0.1 °C / s and the volatility of the intensity value does not exceed 5%, it is determined as a stable trend;

[0054] Step S46: Classify the intensity values into three types: upward trend, downward trend, and stable trend to generate temperature change trend data;

[0055] Step S47: Perform a simulation of the heat accumulation effect of the circuit board according to the temperature change trend data and construct a thermal simulation model of the circuit board.

[0056] The present invention determines the interactive heat flux density value and the interactive temperature value of the circuit board thermal interaction data, which can clarify the heat flow and temperature change conditions between different material layers inside the circuit board during the heat transfer process, and provide key thermal interaction data for subsequent time feature extraction and trend evaluation; extract the time features corresponding to the interactive heat flux density value and the interactive temperature, and perform chronological division to form time series data, which can orderly record the time dynamic characteristics of the thermal interaction process and provide structured time data for subsequent differential processing and trend analysis; perform differential processing on the time series data, use the five-point difference method to calculate the heat flux density change amount and the temperature change amount between adjacent time points, obtain the heat flux density change rate and the temperature change rate, and control the error range within ±2%, which can accurately quantify the dynamic change characteristics in the thermal interaction process and provide high-precision change rate data for the evaluation of the operating temperature change trend; evaluate the operating temperature change trend of the circuit board according to the heat flux density change rate and the temperature change rate, and record the intensity value of the operating temperature change trend, which can comprehensively reflect the temperature change dynamics during the operation of the circuit board and provide a trend basis for subsequent thermal accumulation effect simulation; divide the intensity value into three types: upward trend, downward trend, and stable trend to generate temperature change trend data, which can clearly describe the change mode of the operating temperature of the circuit board and provide clear trend classification information for the construction of the thermal simulation model; perform thermal accumulation effect simulation on the circuit board according to the temperature change trend data and construct a thermal simulation model of the circuit board, which can comprehensively simulate the thermal behavior of the circuit board under different operating conditions and provide reliable thermal simulation for the design optimization, performance evaluation, and fault prediction of the circuit board.

[0057] Preferably, step S47 includes the following steps:

[0058] Step S471: Divide the circuit board simulation area according to the temperature change trend data, and set the initial heat accumulation amount for the circuit board simulation area;

[0059] Step S472: Allocate the initial heat accumulation amount to each time step of each circuit board simulation area as the starting point of the thermal accumulation effect simulation, where the time step range interval is that the minimum step is 1 ms and the maximum step is 100 ms;

[0060] Step S473: Within each time step, calculate the heat accumulation increment of each area according to the temperature change rate; at the end of each time step, accumulate the heat accumulation increment of each area into the current heat accumulation amount of the corresponding area and update the heat accumulation amount of each area;

[0061] Step S474: Repeat the above heat accumulation increment calculation and dynamic update steps, gradually advance the time step until the entire simulation time range is covered;

[0062] Step S475: During the simulation process, record the heat accumulation amount and temperature value at each time step to obtain the sequence data of the heat accumulation effect; construct a thermal simulation model of the circuit board based on the sequence data of the heat accumulation effect.

[0063] According to the temperature change trend data, the present invention divides the circuit board simulation area and sets the initial heat accumulation amount for the circuit board simulation area, which can reasonably divide the simulation area based on the temperature change characteristics and provide clear initial conditions for the heat accumulation effect simulation to ensure that the starting state of the thermal simulation model is consistent with the actual operating state of the circuit board; distribute the initial heat accumulation amount to each time step of each circuit board simulation area as the starting point of the heat accumulation effect simulation, where the time step range is from the minimum step of 1 ms to the maximum step of 100 ms, which can ensure the reasonable distribution of the initial heat accumulation amount within the simulation time, provide precise time step control for the dynamic simulation of the heat accumulation effect, and guarantee the simulation accuracy; within each time step, calculate the heat accumulation increment of each area according to the temperature change rate; at the end of each time step, accumulate the heat accumulation increment of each area to the current heat accumulation amount of the corresponding area and update the heat accumulation amount of each area, which can reflect the heat accumulation change of each area in real time and ensure the dynamic and accurate nature of the heat accumulation effect simulation process; repeat the above heat accumulation increment calculation and dynamic update steps, gradually advancing the time step until the entire simulation time range is covered, which can completely simulate the heat accumulation effect of the circuit board during the entire operation process and ensure that the thermal simulation model can comprehensively reflect the thermal behavior of the circuit board; during the simulation process, record the heat accumulation amount and temperature value at each time step to obtain the sequence data of the heat accumulation effect; construct a thermal simulation model of the circuit board based on the sequence data of the heat accumulation effect, which can generate a high-precision thermal simulation model based on detailed heat accumulation effect data and provide a reliable simulation tool for the thermal performance evaluation and optimization of the circuit board.

[0064] In this specification, a thermal simulation system for a circuit board is provided, which is used to execute the above-mentioned thermal simulation method for a circuit board. The thermal simulation system for a circuit board includes:

[0065] A circuit board layer data acquisition module, which is used to obtain circuit board layer data; extract the board layer material thermal resistance parameters of the circuit board layer data, including copper foil thermal resistance parameters and insulating medium thermal resistance parameters; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data.

[0066] A heat flux density distribution detection module, which is used to determine the component layout characteristics according to the hierarchical structure data, calculate the interlayer thermal resistance distribution of the board layer material thermal resistance parameters based on the component layout characteristics, and generate interlayer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the interlayer structure thermal resistance distribution data.

[0067] A circuit board thermal interaction recognition module, which is used to calculate the joule heat value of the heat flux density distribution data based on the foil thermal resistance parameter and the insulating medium thermal resistance parameter; determine the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value to obtain the circuit board thermal interaction data;

[0068] A circuit board heat accumulation effect simulation module, which is used to evaluate the trend of the operating temperature change of the circuit board based on the circuit board thermal interaction data, generate temperature change trend data; perform circuit board heat accumulation effect simulation according to the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0069] The present invention obtains complete circuit board layer data through a circuit board layer data acquisition module, and accurately extracts the thermal resistance parameters of the board layer materials and the hierarchical structure data; the heat flux density distribution detection module accurately calculates the interlayer thermal resistance distribution and heat flux density distribution data based on the hierarchical structure data and the component layout characteristics; the circuit board thermal interaction recognition module further calculates the joule heat value based on the heat flux density distribution data, determines the heat transfer interaction coefficient, and generates circuit board thermal interaction data; the circuit board heat accumulation effect simulation module uses the thermal interaction data to evaluate the trend of the operating temperature change and perform heat accumulation effect simulation, and finally constructs a high-precision thermal simulation model of the circuit board. The entire system can comprehensively and accurately simulate the thermal behavior of the circuit board, provide a reliable thermal simulation tool for the design optimization, performance evaluation and fault prediction of the circuit board, and significantly improve the thermal management efficiency and reliability of the circuit board.

[0070] A computer-readable medium stores a computer program, wherein the computer program is used to execute the thermal simulation method for the circuit board described above. Description of the Drawings

[0071] Figure 1 It is a schematic diagram of the step flow of a thermal simulation method for a circuit board;

[0072] Figure 2 For Figure 1 It is a schematic diagram of the detailed implementation step flow of step S4 in

[0073] Figure 3 For Figure 2 It is a schematic diagram of the detailed implementation step flow of step S46 in

[0074] The realization, functional characteristics and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0075] The technical method of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0076] In addition, the accompanying drawings are only schematic diagrams of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus repeated descriptions thereof will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. The functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor methods and / or microcontroller methods.

[0077] It should be understood that although terms such as "first" and "second" may be used here to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, the first unit can be called the second unit, and similarly the second unit can be called the first unit. The term "and / or" used here includes any and all combinations of one or more of the listed associated items.

[0078] To achieve the above object, please refer to Figures 1 to 3 , a thermal simulation method for a circuit board, the method comprising the following steps:

[0079] Step S1: Obtain circuit board layer data; extract the board layer material thermal resistance parameters of the circuit board layer data, including copper foil thermal resistance parameters and insulating medium thermal resistance parameters; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data;

[0080] Step S2: Determine the component layout characteristics according to the hierarchical structure data, and calculate the interlayer thermal resistance distribution of the board layer material thermal resistance parameters based on the component layout characteristics to generate layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the layer structure thermal resistance distribution data;

[0081] Step S3: Calculate the joule heat value for the heat flux density distribution data based on the foil thermal resistance parameters and the insulating medium thermal resistance parameters; determine the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value to obtain the circuit board heat interaction data;

[0082] Step S4: Evaluate the changing trend of the operating temperature of the circuit board based on the circuit board thermal interaction data to generate temperature change trend data; perform a thermal accumulation effect simulation on the circuit board according to the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0083] By obtaining the circuit board layer data, the present invention can accurately extract the thermal resistance parameters of the copper foil and the thermal resistance parameters of the insulating medium, providing accurate basic data for subsequent thermal simulation calculations and ensuring the accuracy of subsequent thermal simulation analysis; identifying the hierarchical structure of the circuit board layer data and recording it as hierarchical structure data enables a clear understanding of the structural characteristics of the circuit board, providing a clear structural basis for subsequent analysis of the component layout characteristics and calculation of the interlayer thermal resistance distribution based on the hierarchical structure; after determining the component layout characteristics according to the hierarchical structure data, calculating the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on this feature, the generated interlayer structure thermal resistance distribution data can accurately reflect the thermal resistance situation between the layers of the circuit board, providing a reliable thermal resistance distribution basis for the calculation of subsequent heat flux density distribution data; detecting the interlayer via routing characteristics based on the component layout characteristics and calculating the heat flux density distribution data based on the interlayer structure thermal resistance distribution data can accurately simulate the heat flux density situation in each area of the circuit board during actual operation, providing accurate heat flux density information for subsequent calculation of the Joule heat value; calculating the Joule heat value based on the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters for the heat flux density distribution data can accurately obtain the Joule heat value generated by each part of the circuit board, providing accurate heat value data for subsequent determination of the heat transfer interaction coefficient; determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the Joule heat value, the obtained circuit board thermal interaction data can truly reflect the heat transfer situation between different material layers inside the circuit board, providing key thermal interaction information for subsequent evaluation of the changing trend of the operating temperature; evaluating the changing trend of the operating temperature of the circuit board based on the circuit board thermal interaction data, the generated temperature change trend data can accurately predict the temperature change situation of the circuit board under different operating conditions, providing an important reference basis for the thermal management and reliability evaluation of the circuit board; performing a thermal accumulation effect simulation on the circuit board according to the temperature change trend data and constructing a thermal simulation model of the circuit board, which can comprehensively and accurately simulate the thermal behavior of the circuit board during actual operation. Therefore, the present invention realizes the thermal transfer interaction analysis of the copper foil layer and the insulating medium layer of the circuit board through data processing technology and simulation technology, and realizes the evaluation of the thermal transfer direction and thermal accumulation effect of the circuit board to construct a thermal simulation model of the circuit board.

[0084] In an embodiment of the present invention, refer to Figure 1 As shown, it is a schematic diagram of the step flow of a thermal simulation method for a circuit board according to the present invention. In this example, the thermal simulation method for a circuit board includes the following steps:

[0085] Step S1: Obtain the circuit board layer data; extract the thermal resistance parameters of the board layer materials of the circuit board layer data, including the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data;

[0086] In the embodiments of the present invention, use the Altium Designer software to open the designed PCB project file. In the PCB editing interface, select "File>Fabrication Outputs>Gerber Files" through the menu bar to enter the Gerber file export settings interface. In the settings interface, select the appropriate unit (usually inches) and format (such as 2:5), and ensure that all required layers (such as the conductor layer, solder mask layer, silk screen layer, etc.) are selected. Especially note that for multi-layer boards, ensure that the pad and connection information of the intermediate layer are correctly included. After the settings are completed, click the "Generate" button to generate the Gerber file, and the file will be saved in the "Project Outputs for [project name]" folder under the specified project directory; Extract the thickness information of the copper foil from the circuit board design file (such as Gerber file or the project file of the PCB design software). The copper foil thickness is usually recorded in the material property field in micrometers (μm). For example, in Altium Designer, the thickness of the copper foil of each layer can be viewed through the "Material Properties" panel; According to the thickness, purity and thermal conductivity of the copper foil (usually the thermal conductivity of pure copper, about 398 W / (m·K)), combined with the actual distribution area of the copper foil, calculate the thermal resistance of the copper foil. The thermal resistance is inversely proportional to the thickness of the copper foil and inversely proportional to the area of the copper foil. Specifically, the thicker the copper foil thickness and the larger the area, the lower the thermal resistance. Extract the type (such as FR-4, CE, etc.) and thickness information of the insulating medium from the circuit board design file. The thermal conductivity of the insulating medium is a known material property parameter, which can usually be found in the material database. For example, the thermal conductivity of FR-4 material is about 0.3 W / (m·K); According to the thickness and thermal conductivity of the insulating medium, combined with its distribution area in the circuit board, calculate the thermal resistance of the insulating medium. The thermal resistance is proportional to the thickness of the insulating medium and inversely proportional to the thermal conductivity. Specifically, the thicker the insulating medium thickness and the lower the thermal conductivity, the higher the thermal resistance; Use the layer identification function of the circuit board design software to analyze the layer structure of the circuit board. The software will read the layer information in the Gerber file and identify the layer structure of the circuit board, such as the top layer (TopLayer), bottom layer (BottomLayer), intermediate signal layer (MidLayer), power layer (PowerLayer) and ground layer (GroundLayer). By analyzing the connection relationship and layout characteristics of each layer, the software can determine the relative position and connection method between each layer. For example, confirm the accuracy of the interlayer connection by checking the alignment marks and connection holes between the layers. After the identification is completed, the software will record the layer structure information in a data format to form the layer structure data.

[0087] Step S2: Determine the component layout characteristics based on the hierarchical structure data, and calculate the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate the layer structure thermal resistance distribution data; Detect the interlayer via routing characteristics based on the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via routing characteristics for the layer structure thermal resistance distribution data;

[0088] In the embodiment of the present invention, a professional printed circuit board design software (such as Altium Designer or Cadence) is used to open the hierarchical structure file of the printed circuit board (such as Gerber file or ODB++ file). Through the layout analysis function of the software, the layout information of the components is extracted, including the type, size, location of the components, and specific information distributed on different board layers. The software will output this information in the form of a data table. Each row in the data table corresponds to a component, and the columns include detailed information such as component number, type, size, center coordinates (X, Y), and the number of the board layer where it is located; Obtain the thermal conductivity and thickness parameters of each layer of materials from the material specification sheet of the printed circuit board. For example, for a common multi-layer printed circuit board, the inner layer usually uses glass fiber-reinforced epoxy resin (FR-4), whose thermal conductivity is 0.3 W / m·K and thickness is 0.5 mm. According to these parameters, combined with the component layout characteristics, calculate the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials; Read the thermal conductivity and thickness parameters of each layer of materials from the material specification sheet; For the area where each component is located, calculate the thermal resistance of this area according to its projected area on the board layer, combined with the thermal conductivity and thickness of the material. After the calculation is completed, store the thermal resistance value of each area as the layer structure thermal resistance distribution data, forming a two-dimensional array, and each element of the array corresponds to the thermal resistance value of an area; Use the printed circuit board design software to open the drilling file, and extract the position coordinates (X, Y), diameter, and layer pair information connected of the vias. The software will output this information in the form of a data table. Each row in the data table corresponds to a via, and the columns include detailed information such as via number, center coordinates (X, Y), diameter, and the number of the layer pair connected; For each via, calculate the thermal resistance of the via according to its diameter and the spacing of the connected layer pairs, combined with the thermal conductivity of the material. After the calculation is completed, store the thermal resistance value of the via as the via thermal resistance distribution data, forming a two-dimensional array, and each element of the array corresponds to the thermal resistance value of a via; Calculate the heat flow of each area and via according to the temperature difference and thermal resistance. The temperature difference can be obtained by measurement or preset temperature conditions. The calculation process of the heat flow is to divide the temperature difference by the thermal resistance, and the result obtained is the heat flow; Calculate the heat flux density of each area and via according to the heat flow and the heat conduction area. The calculation process of the heat flux density is to divide the heat flow by the heat conduction area, and the result obtained is the heat flux density; Assign the calculated heat flux density values to each area and via to form the complete heat flux density distribution data. The heat flux density distribution data is also stored as a two-dimensional array.

[0089] Step S3: Calculate the joule heat value for the heat flux density distribution data based on the foil thermal resistance parameter and the insulating dielectric thermal resistance parameter; determine the heat transfer interaction coefficient between the copper foil layer and the insulating dielectric layer through the joule heat value to obtain the heat interaction data of the circuit board;

[0090] In the embodiment of the present invention, first, relevant parameters of the copper foil layer and the insulating dielectric layer are obtained from the material specification of the circuit board. For the copper foil layer, its resistivity, thickness, and area are recorded; for the insulating dielectric layer, its thermal conductivity, thickness, and area are recorded. At the same time, the current intensity passing through the copper foil and the energization time are obtained from the electrical design document of the circuit board. Then, calculate the resistance value of the copper foil. According to Ohm's law, the resistance value is equal to the resistivity multiplied by the copper foil length divided by the copper foil cross-sectional area. In actual operation, since the copper foil of the circuit board is usually multi-segmented and complex in shape, the copper foil needs to be divided into multiple small segments, the resistance value of each segment is calculated separately, and then the resistance values of all small segments are added together to obtain the total resistance value of the entire copper foil; then, calculate the joule heat value using Joule's law. The joule heat value is equal to the square of the current intensity multiplied by the total resistance value of the copper foil and then multiplied by the energization time. The calculated joule heat value will be used as the heat source for subsequent heat transfer analysis. After that, determine the heat transfer interaction coefficient between the copper foil layer and the insulating dielectric layer. Combine the joule heat value with the thermal resistance of the copper foil layer and the thermal resistance of the insulating dielectric layer, and calculate the heat transfer interaction coefficient through numerical methods. The finite difference method is used for calculation. The copper foil layer and the insulating dielectric layer are divided into multiple small units. According to the thermal resistance of each unit and the temperature difference between adjacent units, calculate the heat flux density. Calculate the heat transfer interaction coefficient of each unit according to the heat flux density and the unit area; perform weighted averaging on the heat transfer interaction coefficients of all units to obtain the heat transfer interaction coefficient of the entire circuit board; during the calculation process, reasonable boundary conditions and initial conditions are set. The boundary conditions include the boundary temperature and heat flux density of the circuit board, and the initial conditions include the initial temperatures of the copper foil layer and the insulating dielectric layer. According to the actual working environment and initial state of the circuit board, determine the specific values of the boundary conditions and initial conditions. Finally, combine the calculated heat transfer interaction coefficient with the joule heat value to obtain the heat interaction data of the circuit board. These data include information such as the heat flux density and temperature distribution between the copper foil layer and the insulating dielectric layer, which can be used for subsequent heat simulation analysis. Output the heat interaction data in the form of a table or a graph.

[0091] Step S4: Evaluate the changing trend of the operating temperature of the circuit board based on the heat interaction data of the circuit board to generate temperature change trend data; perform a heat accumulation effect simulation on the circuit board according to the temperature change trend data and construct a heat simulation model of the circuit board.

[0092] In the embodiments of the present invention, the operating temperature change trend of the circuit board is evaluated based on the circuit board thermal interaction data. Key parameters of temperature change are extracted from the thermal interaction data, including temperature values, timestamps, and the corresponding heat flux density distributions. These data are imported into thermal analysis software (such as ANSYS or Icepak), and a suitable value within the range of 1 ms to 100 ms is set for the time step to ensure simulation accuracy and calculation efficiency. In the software, according to the temperature change rate and the time step, the temperature change trend within each time step is calculated. Specifically, the temperature change rate is multiplied by the time step to obtain the temperature change amount within each time step, and then these change amounts are accumulated to the initial temperature to obtain the temperature value at the end of each time step. These temperature values are arranged in chronological order to generate temperature change trend data, which are output in the form of a table or a graph for subsequent analysis. Then, the thermal accumulation effect simulation of the circuit board is carried out according to the temperature change trend data. In the thermal analysis software, the initial thermal accumulation amount is set to zero or a reasonable initial value is set according to the actual working conditions. Within each time step, according to the heat flux density distribution data and the temperature change trend, the thermal accumulation increment of each region is calculated. Specifically, the heat flux density is multiplied by the time step to obtain the thermal accumulation increment of each region within this time step. These thermal accumulation increments are accumulated to the initial thermal accumulation amount to obtain the thermal accumulation amount at the end of each time step. Repeat the above steps, gradually advancing the time step until the entire simulation time range is covered. During the simulation process, the thermal accumulation amount and temperature value of each time step are recorded to form thermal accumulation effect sequence data. Finally, a thermal simulation model of the circuit board is constructed according to the thermal accumulation effect sequence data. The thermal accumulation effect sequence data are imported into the thermal simulation software, and through data processing and analysis techniques, key features of thermal accumulation are extracted, such as the change trend of the thermal accumulation amount and the fluctuation of the temperature, etc. These features will be used to construct the thermal simulation model to simulate the thermal behavior of the circuit board under different operating conditions. When constructing the model, according to the thermal accumulation effect sequence data, parameters such as the initial conditions, boundary conditions, and material properties of the model are set. Through methods such as finite element analysis (FEA) or computational fluid dynamics (CFD), the model is solved to obtain the thermal distribution and temperature change of the circuit board.

[0093] Preferably, step S1 includes the following steps:

[0094] Step S11: Obtain the structural parameters, material information, and connection point distribution information of the circuit board respectively to obtain the circuit board layer data;

[0095] Step S12: Identify the copper foil layer and the insulating dielectric layer from the circuit board layer data, mark the boundary positions of the copper foil layer and the insulating dielectric layer, and extract the thermal resistance parameters of the copper foil layer and the insulating dielectric layer to obtain the thermal resistance parameters of the board layer materials;

[0096] Step S13: Obtain the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter of the board layer material thermal resistance parameter respectively;

[0097] Step S14: Scan layer by layer from the circuit board layer data, determine the boundary range of each layer, and mark it as the start and end points of each layer; the scanning speed is 10 layers per second, and the thickness accuracy of each layer is 0.001 mm;

[0098] Step S15: Number each layer, and record the layer numbers and the thicknesses of each layer in order from the outside to the inside;

[0099] Step S16: For two adjacent layers, determine whether there is a connection relationship between the two adjacent layers, and record the connection relationship of the adjacent layer positions;

[0100] Step S17: Integrate the start and end points of each layer, the layer numbers of each layer, the thicknesses of each layer, and the connection relationship of the adjacent layer positions into hierarchical structure data.

[0101] In the embodiments of the present invention, a professional circuit board detection device, such as an optical measuring instrument or an X-ray detection device, is used to perform non-contact scanning on the circuit board. Structural parameters such as the size, number of layers, and line width of the circuit board are obtained through the optical measuring instrument; at the same time, the X-ray detection device is used to penetrate the insulating layer to identify the distribution of the internal copper foil layer and connection points. Combining with the design file of the circuit board, such as the Gerber file, the material information of the circuit board is further confirmed, including the thickness of the copper foil and the type of insulating medium (such as FR-4, Rogers, etc.). These information are integrated into the circuit board layer data and stored in the database for subsequent processing; image processing technology is used to analyze the circuit board layer data. Using edge detection algorithms, such as the Canny edge detection algorithm, to identify the boundary positions between the copper foil layer and the insulating medium layer. After the boundaries are identified, through the finite element analysis method, according to Fourier's law of heat conduction, the thermal resistance parameters of the copper foil layer and the insulating medium layer are calculated. The thermal resistance values of the copper foil layer and the insulating medium layer are calculated through parameters such as the thermal conductivity, specific heat capacity, and thermal diffusivity of the material, and these parameters are stored as the thermal resistance parameters of the board layer material; from the stored thermal resistance parameters of the board layer material, the thermal resistance parameters of the copper foil layer and the insulating medium layer are extracted respectively. The thermal resistance parameters of the copper foil layer are mainly determined by its thickness, thermal conductivity, and specific heat capacity, while the thermal resistance parameters of the insulating medium layer are determined by the thermal conductivity and thickness of its material. The thermal resistance values of the copper foil layer and the insulating medium layer are calculated respectively, and these parameters are stored as the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; a high-precision optical scanning device is used to scan the circuit board layer by layer at a speed of 10 layers per second. During the scanning process, the accuracy of the device is set to 0.001 mm for the thickness accuracy of each layer to ensure that the boundary range of each layer can be accurately identified. After the scanning is completed, according to the scanning data, the starting point and ending point of each layer are marked, and this information is stored as the start and end point data of each layer; according to the order from the outside to the inside, each layer of the circuit board is numbered. The numbering starts from the outermost layer and proceeds inward in turn to ensure the uniqueness and sequentiality of the numbering. At the same time, combining with the start and end point data of each layer obtained in step S14, the thickness of each layer is calculated, and the layer number and thickness information of each layer are stored in the database; image recognition technology is used to analyze the distribution of connection points between adjacent layers. By identifying vias or other connection structures, it is judged whether there is an electrical connection relationship between adjacent layers. If there is a connection relationship, the layer numbers of the adjacent layers and the position information of the connection points are recorded and stored as the adjacent layer position connection relationship data; the start and end point data of each layer obtained in step S14, the layer number and thickness data of each layer recorded in step S15, and the adjacent layer position connection relationship data recorded in step S16 are integrated. Through data fusion technology, these information are integrated into a complete hierarchical structure data file for subsequent circuit board thermal simulation analysis.

[0102] Preferably, in step S2, determining the component layout characteristics according to the hierarchical structure data and calculating the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on the component layout characteristics includes:

[0103] Determine the component information of each layer from the hierarchical structure data and identify the boundary lines of the component information to obtain the component shape and size;

[0104] Number the coordinates of the component shape and size, and mark the positions of the components in sequence from left to right and from top to bottom to generate the component position coordinates;

[0105] Determine the distance between adjacent components and the distance between the components and the edge of the circuit board according to the component position coordinates to obtain the component layout distance parameters;

[0106] Integrate the component shape and size, the component position coordinates, and the component layout distance parameters into the component layout characteristics;

[0107] Determine the thermal resistance contribution area of the components on the circuit board according to the component layout characteristics, and calculate the thermal resistance values in different board layers based on the thermal resistance contribution area of the components;

[0108] Between adjacent board layers, detect the thermal resistance coupling area according to the layout characteristics of the components; calculate the interlayer thermal resistance value of the adjacent board layer coupling area based on the thermal resistance coupling area to obtain the layer structure thermal resistance distribution data.

[0109] In the embodiments of the present invention, image processing technology is used to analyze hierarchical structure data. The boundary lines of components are recognized through edge detection algorithms (such as the Canny algorithm), thereby determining the shape and size of the components. During the recognition process, combined with the layout information of the components, such as their approximate positions and directions on the board, the recognition of the boundary lines is further refined. For example, for rectangular components, their four corner points are recognized and their length and width dimensions are calculated; for circular components, their centers and radii are recognized. The recognized component shape and size information is stored as component shape and size data; according to the component shape and size data, combined with the overall size and layout direction of the circuit board, a coordinate system is used to number and mark the positions of the components. Taking the upper left corner of the circuit board as the coordinate origin, the horizontal direction is the X-axis, and the vertical direction is the Y-axis. In the order from left to right and from top to bottom, coordinate numbers are assigned to each component in turn. For example, the coordinate number of the first component is (1,1), the coordinate number of the second component is (2,1), and so on. These coordinate numbers are stored as component position coordinate data; based on the component position coordinate data, the spacing between adjacent components is calculated. By calculating the Euclidean distance between the coordinates of adjacent components, their horizontal and vertical spacings are obtained. At the same time, the distances between each component and the edges of the circuit board are calculated, including the distances to the upper, lower, left, and right edges. For example, for a component located at coordinates (3,2), its distance from the left boundary of the circuit board is 3 unit lengths, and its distance from the upper boundary is 2 unit lengths. These spacing and distance information are integrated into component layout distance parameter data; the component shape and size data, component position coordinate data, and component layout distance parameter data are integrated. Through data fusion technology, these information are arranged in the order of component numbers to form a complete component layout feature data file. This file contains the shape and size, position coordinates of each component, and the distances to adjacent components and the edges of the circuit board, providing basic data for subsequent thermal resistance calculations; according to the component layout feature data, the thermal resistance contribution regions of each component in different board layers are determined. The thermal resistance contribution region refers to the range of the thermal resistance influence of the component on the surrounding region during heat conduction. For each component, according to its shape and size and position coordinates, combined with the material thermal conductivity and thickness of the circuit board, the finite element analysis method is used to calculate its thermal resistance values in different board layers. For example, for a rectangular component located on the top layer, the calculated thermal resistance value is stored as component thermal resistance contribution data; using the component layout feature data, the thermal resistance coupling regions between adjacent board layers are detected. The thermal resistance coupling region refers to the region where the thermal resistances between adjacent board layers affect each other due to the component layout. By analyzing the position coordinates and shape and size of the components, the boundaries of the coupling region are determined.In the coupling region, a multi-physics coupling calculation method is used to calculate the interlayer thermal resistance value between adjacent board layers considering the influence of contact thermal resistance; for the coupling region between two adjacent board layers, the calculated interlayer thermal resistance value is stored as the layer structure thermal resistance distribution data.

[0110] Preferably, detecting the interlayer via routing features according to the component layout features in step S2 and calculating the heat flux density distribution data based on the interlayer via routing features includes:

[0111] Determine the via requirements of components on different board layers according to the component layout features, and determine the hole position distribution coordinates according to the via requirements;

[0112] Detect the via setting conditions of the hole position distribution coordinates, including the aperture deviation amount and the via center offset degree;

[0113] Detect the vertical alignment degree of vias between different board layers according to the aperture deviation amount to obtain the via vertical alignment degree; detect the offset amount of vias during interlayer penetration according to the via center offset degree to obtain the via interlayer offset amount;

[0114] Judge the interlayer via routing relationship based on the via vertical alignment degree and the via interlayer offset amount to generate the interlayer via routing features;

[0115] Determine the hole distribution density and the distance between holes of the vias according to the interlayer via routing features;

[0116] Identify the board heat flow path of the printed circuit board based on the hole distribution density and the distance between holes, and divide the board heat flow path into a heat flow convergence region and a heat flow dispersion region;

[0117] For the heat flow convergence region, calculate the heat flux density increase multiple of the printed circuit board according to the hole distribution density, and record the regional heat flux density peak value;

[0118] For the heat flow dispersion region, calculate the heat flux uniformity coefficient of the printed circuit board according to the distance between holes, and record the regional heat flux uniformity coefficient;

[0119] Measure the heat flux density distribution of the layer structure thermal resistance distribution data based on the regional heat flux density peak value and the regional heat flux uniformity coefficient to generate the heat flux density distribution data.

[0120] In the embodiments of the present invention, by analyzing the component layout feature data and combining with the electrical connection requirements of the circuit board, the via requirements between different board layers for components are determined. Using professional PCB design software (such as Altium Designer or Cadence), according to the pin distribution and connection paths of the components, the positions of the vias are planned. During the design process, a suitable via diameter is selected according to the wiring density and current-carrying capacity of the circuit board, usually not less than 0.3 mm. Through the automatic layout function of the software, the coordinate distribution of the via positions is generated and stored as via position distribution coordinate data; using high-precision optical detection equipment or X-ray detection equipment, the vias in the via position distribution coordinates are detected. The detection equipment measures the actual aperture of each via through image recognition technology and compares it with the design value to calculate the aperture deviation. At the same time, the offset between the via center and the design coordinate is detected to obtain the via center offset degree. The detection accuracy should reach ±0.01 mm to ensure the accuracy of the measurement results; through the layer alignment detection technology of the multi-layer circuit board, the via images of different board layers are superimposed and compared. Using image processing algorithms, the vertical alignment degree of the vias between different board layers is calculated, that is, the deviation of the via center in the vertical direction. At the same time, according to the via center offset degree, the horizontal offset amount during the inter-layer penetration of the vias is detected. The detection results of the vertical alignment degree and the inter-layer offset amount will be used for subsequent wiring relationship judgment; according to the detection results of the via vertical alignment degree and the inter-layer offset amount, the wiring relationship of the vias between different board layers is judged. If both the vertical alignment degree and the inter-layer offset amount are within the design allowable range (usually ±0.05 mm), the via wiring relationship is considered good; otherwise, the vias need to be readjusted or repaired. The wiring relationship information of the vias is stored as inter-layer via wiring feature data; by analyzing the inter-layer via wiring feature data, the distribution density and the distance between vias of the vias are calculated. The via distribution density refers to the number of vias per unit area, which is obtained by counting the total number of vias and the area of the circuit board. The distance between vias refers to the distance between the centers of adjacent vias, which is obtained through measurement and calculation. According to the via distribution density and the distance between vias, the wiring density and heat dissipation performance of the circuit board are evaluated; using heat flow analysis software (such as FloTHERM or ANSYS Icepak), combining the via distribution density and the distance between vias data, the heat flow path of the circuit board is identified. According to the distribution of the heat flow density, the circuit board is divided into a heat flow convergence area and a heat flow dispersion area. The heat flow convergence area refers to the area where the vias are densely distributed and the heat flow density is relatively high; the heat flow dispersion area refers to the area where the vias are sparsely distributed and the heat flow density is relatively low; in the heat flow convergence area, by analyzing the hole distribution density, the increase multiple of the heat flow density is calculated. The increase multiple of the heat flow density refers to the ratio of the heat flow density in the heat flow convergence area to the average heat flow density. At the same time, the peak value of the heat flow density in the heat flow convergence area is recorded for evaluating the heat dissipation requirement of this area; in the heat flow dispersion area, by analyzing the distance between vias, the heat flow uniformity coefficient is calculated.The heat flux uniformity coefficient reflects the uniformity of the heat flux distribution. The smaller the coefficient, the more uniform the heat flux distribution. Record the heat flux uniformity coefficient of the heat flux dispersion area to evaluate the heat dissipation uniformity of this area; according to the peak value of the heat flux density in the heat flux convergence area and the heat flux uniformity coefficient of the heat flux dispersion area, conduct heat flux density distribution measurement on the thermal resistance distribution data of the layer structure; generate heat flux density distribution data through thermal simulation software, and this data reflects the heat flux density conditions of the circuit board in different areas.

[0121] Preferably, the calculation of the joule heat value for the heat flux density distribution data based on the foil thermal resistance parameter and the insulating medium thermal resistance parameter in step S3 includes:

[0122] Determine the corresponding area of the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter respectively to obtain the copper foil thermal resistance area and the insulating medium thermal resistance area;

[0123] Conduct area density ratio calculation on the heat flux density distribution data based on the copper foil thermal resistance area and the insulating medium thermal resistance area to obtain the heat flux density area ratio value;

[0124] Calculate the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area respectively according to the heat flux density area ratio value; and combine the joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area to generate the joule heat value.

[0125] In the embodiments of the present invention, a professional PCB design software (such as Altium Designer or Cadence) is used to divide the regions of the copper foil layer and the insulating dielectric layer in combination with the hierarchical structure data of the circuit board and the component layout characteristics. Through the automatic layout function of the software, the distribution regions of the copper foil layer and the insulating dielectric layer are identified, and the respective region areas are calculated. In specific operations, first, the hierarchical structure data of the circuit board is imported, and then the region analysis tool of the software is used to calculate the copper foil thermal resistance region area and the insulating dielectric thermal resistance region area respectively according to the boundary information of the copper foil layer and the insulating dielectric layer; according to the copper foil thermal resistance region area and the insulating dielectric thermal resistance region area, combined with the heat flux density distribution data, the area density ratio calculation is performed. The specific operation is as follows: divide the copper foil thermal resistance region area and the insulating dielectric thermal resistance region area by the total effective heat dissipation area of the circuit board respectively to obtain their respective area ratios. Then, the heat flux density distribution data is weighted with these area ratios to obtain the heat flux density area ratio value. This process can be completed by a thermal simulation software (such as FloTHERM or ANSYS Icepak), and the software will automatically generate the heat flux density area ratio value according to the input region area and heat flux density data; using the heat flux density area ratio value, combined with the power consumption data of the circuit board, the joule heat of the copper foil thermal resistance region area and the insulating dielectric thermal resistance region area is calculated respectively. The specific operation is as follows: according to the heat flux density area ratio value, the total power consumption of the circuit board is allocated to the copper foil thermal resistance region and the insulating dielectric thermal resistance region. For example, if the heat flux density area ratio of the copper foil thermal resistance region is 60%, the heat flux density area ratio of the insulating dielectric thermal resistance region is 40%, and the total power consumption of the circuit board is 10W, then the joule heat of the copper foil thermal resistance region is 6W, and the joule heat of the insulating dielectric thermal resistance region is 4W. Finally, the joule heats of these two regions are combined to generate the total joule heat value of the circuit board.

[0126] Preferably, the determination of the heat transfer interaction coefficient between the copper foil layer and the insulating dielectric layer in step S3 includes:

[0127] Calculate the joule heat ratio of the copper foil layer and the insulating dielectric layer according to the joule heat value to obtain the thermal energy ratio of the two layers;

[0128] Based on the thermal energy ratio of the two layers, determine the heat transfer direction between the copper foil layer and the insulating dielectric layer to generate the interlayer heat transfer direction; if the thermal energy ratio of the two layers is greater than or equal to 1, the heat transfer direction is from the copper foil layer to the insulating dielectric layer; if the thermal energy ratio of the two layers is less than 1, the heat transfer direction is from the insulating dielectric layer to the copper foil layer;

[0129] Judge the heat transfer interaction coefficient through the interlayer heat transfer direction, and record the circuit board layer information corresponding to the heat transfer interaction coefficient to obtain the circuit board heat interaction data.

[0130] In the embodiments of the present invention, in a thermal simulation software (such as ANSYS Icepak), the thermal simulation result data of the circuit board is imported, and the joule heat values of the copper foil layer and the insulating dielectric layer are extracted. The specific operation is as follows: In the "thermal analysis" module of the software, select the "joule heat calculation" function, and input the power consumption distribution data of the copper foil layer and the insulating dielectric layer respectively. The software will calculate the joule heat values of the copper foil layer and the insulating dielectric layer according to the input data. Subsequently, through the "parameter calculation" function of the software, divide the joule heat value of the copper foil layer by the joule heat value of the insulating dielectric layer to obtain the thermal energy ratio of the two layers; in the ANSYS Icepak software, according to the calculated thermal energy ratio of the two layers, judge the heat transfer direction. The specific operation is as follows: In the "heat transfer direction judgment" module, input the thermal energy ratio of the two layers. If the joule heat ratio is greater than or equal to 1, the software will automatically mark the heat transfer direction as "from the copper foil layer to the insulating dielectric layer"; if the joule heat ratio is less than 1, it will be marked as "from the insulating dielectric layer to the copper foil layer". The software will output and save the judgment result in the form of "inter-layer heat transfer direction" data; in the ANSYS Icepak software, according to the inter-layer heat transfer direction, further calculate the heat transfer interaction coefficient. The specific operation is as follows: In the "heat transfer interaction coefficient calculation" module, input the inter-layer heat transfer direction data and the material properties (such as thermal conductivity, specific heat capacity, etc.) of the copper foil layer and the insulating dielectric layer. The software will automatically calculate the heat transfer interaction coefficient according to these parameters and in combination with the heat transfer direction. After the calculation is completed, the software will record the heat transfer interaction coefficient together with the corresponding circuit board layer information (such as the number of layers, material type, etc.) in the "circuit board thermal interaction data" file.

[0131] As an example of the present invention, refer to Figure 2 As shown, in this example, step S4 includes:

[0132] Step S41: Determine the interactive heat flux density value and the interactive temperature value of the circuit board thermal interaction data;

[0133] Step S42: Extract the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and perform chronological division to form time series data;

[0134] Step S43: Perform differential processing on the time series data, calculate the change in heat flux density and the change in temperature between adjacent time points to obtain the heat flux density change rate and the temperature change rate, where the differential processing uses the five-point differential method and controls the error range within ±2%;

[0135] Step S44: Evaluate the operating temperature change trend of the circuit board according to the heat flux density change rate and the temperature change rate, and record the intensity value of the operating temperature change trend;

[0136] Step S45: When the intensity values at three consecutive time points are all greater than 0.1 °C / s and the increase rate of the intensity value exceeds 10%, it is determined as an upward trend; when the intensity values at three consecutive time points are all less than -0.1 °C / s and the decrease rate of the intensity value exceeds 10%, it is determined as a downward trend; when the intensity values at three consecutive time points are all less than 0.1 °C / s and the volatility of the intensity value does not exceed 5%, it is determined as a stable trend;

[0137] Step S46: Classify the intensity values into three types: upward trend, downward trend, and stable trend to generate temperature change trend data;

[0138] Step S47: Conduct a simulation of the thermal accumulation effect of the circuit board based on the temperature change trend data and construct a thermal simulation model of the circuit board.

[0139] In the embodiments of the present invention, a high-precision heat flux sensor array is attached to the key heat interaction areas of the circuit board, including the connection between the chip and the substrate, the vicinity of the heat dissipation holes, and the large current trace area. The sensor array consists of multiple high-precision heat flux sensors. The measurement range of each sensor is 0 to 1000 W / m², the accuracy is ±0.1 W / m², and the sampling frequency is 100 Hz. At the same time, high-precision temperature sensors are arranged at the same positions. The measurement range of the temperature sensors is -50 to 200 °C, the accuracy is ±0.05 °C, and the sampling frequency is also 100 Hz. The signals of the heat flux sensors and the temperature sensors are synchronously collected by a data acquisition card. The data acquisition card has a multi-channel input function, can receive the signals of the heat flux sensors and the temperature sensors simultaneously, and perform amplification and filtering processing. The filtering processing uses a low-pass filter with a cut-off frequency of 50 Hz to remove high-frequency noise interference. The processed data is transmitted to the data processing system in the form of digital signals. The system analyzes and stores the received data, and finally obtains the interactive heat flux density value and the interactive temperature value of the circuit board heat interaction data; extract the interactive heat flux density value and the interactive temperature value obtained in step S41 from the data processing system. Each data point is accompanied by a timestamp. The unit of the timestamp is seconds, accurate to three decimal places. The data processing system pairs the heat flux density value and the temperature value corresponding to each time point to form a triple data structure containing the timestamp, the heat flux density value, and the temperature value. For example, the data structure at a certain time point is (timestamp, heat flux density value, temperature value). Arrange all the paired data in ascending order of the timestamp. During the arrangement process, the system checks the continuity of the timestamps to ensure that the data is arranged in chronological order. If it is found that the timestamps are missing or repeated, the system will automatically perform interpolation or elimination operations to ensure the integrity of the time series data. Finally, a complete time series data arranged in chronological order is obtained, where each data point contains the corresponding timestamp, heat flux density value, and temperature value; input the time series data formed in step S42 into the difference processing module. The difference processing module processes the data using the five-point difference method. The five-point difference method is a difference algorithm based on five adjacent data points, which can effectively reduce the influence of single-point errors. For each data point in the time series (from the 3rd data point to the 3rd data point from the end), the difference processing module first extracts the heat flux density value and the temperature value of this data point and its two previous and two subsequent data points. Then, according to the rules of the five-point difference method, calculate the heat flux density change rate and the temperature change rate of this data point. The specific operations are as follows: Calculation of the heat flux density change rate: The difference processing module performs weighted calculation on the heat flux density values of the current data point and its two previous and two subsequent data points to obtain the heat flux density change rate of the current data point. The weighting coefficients are preset according to the rules of the five-point difference method to ensure that the calculation results can reflect the change trend of the heat flux density at this time point.Calculation of temperature change rate: Similarly, the differential processing module performs weighted calculation on the temperature values of the current data point and its two adjacent data points to obtain the temperature change rate of the current data point. The weighting coefficients are the same as those in the calculation of the heat flux density change rate, ensuring that the temperature change rate can accurately reflect the temperature change trend at this time point. Comprehensive analysis is performed on the heat flux density change rate and temperature change rate at each time point. Trend judgment: When both the heat flux density change rate and the temperature change rate are positive, it is judged that the circuit board is in a warming trend at this moment. When both the heat flux density change rate and the temperature change rate are negative, it is judged that the circuit board is in a cooling trend at this moment. When the absolute values of both the heat flux density change rate and the temperature change rate are less than a preset threshold (e.g., 0.01 W / m² / s and 0.01 °C / s), it is judged that the circuit board is in a stable trend at this moment. Calculation of intensity value: For each time point, the trend evaluation module comprehensively processes the values of the heat flux density change rate and the temperature change rate to calculate an intensity value. The magnitude of the intensity value reflects the severity of the temperature change at this time point. The specific operation is to normalize the values of the heat flux density change rate and the temperature change rate, and then add the normalized values to obtain the final intensity value. When the intensity values at three consecutive time points are all greater than 0.1 °C / s and the intensity value increase rate exceeds 10%, it is determined as an upward trend; when the intensity values at three consecutive time points are all less than -0.1 °C / s and the intensity value decrease rate exceeds 10%, it is determined as a downward trend; when the intensity values at three consecutive time points are all less than 0.1 °C / s and the intensity value volatility does not exceed 5%, it is determined as a stable trend; First, based on the temperature change trend data, determine the heat input and output of the circuit board in each time period. Heat input includes the heat generated by the chip, the heat from external heat sources, etc.; heat output includes the heat dissipated through heat dissipation holes, heat sinks and other heat dissipation structures; The simulation module calculates the heat accumulation amount of the circuit board in each time period according to the difference between the heat input and output. The heat accumulation amount reflects the degree of heat accumulation inside the circuit board and is an important factor affecting the temperature change of the circuit board; The simulation module combines the heat accumulation amount with the temperature change trend data to simulate the temperature change process of the circuit board under different operating conditions.

[0140] As an example of the present invention, refer to Figure 3 shown, in this example, step S47 includes:

[0141] Step S471: Divide the circuit board simulation area according to the temperature change trend data, and set the initial heat accumulation amount for the circuit board simulation area;

[0142] Step S472: Allocate the initial heat accumulation amount to each time step of each circuit board simulation area as the starting point for heat accumulation effect simulation, where the time step range is from a minimum step of 1 ms to a maximum step of 100 ms;

[0143] Step S473: Within each time step, calculate the thermal accumulation increment for each region based on the temperature change rate; at the end of each time step, add the thermal accumulation increment of each region to the current thermal accumulation of the corresponding region and update the thermal accumulation of each region;

[0144] Step S474: Repeat the above thermal accumulation increment calculation and dynamic update steps, gradually advancing the time step until the entire simulation time range is covered;

[0145] Step S475: During the simulation process, record the thermal accumulation and temperature values at each time step to obtain the thermal accumulation effect sequence data; construct a thermal simulation model of the circuit board based on the thermal accumulation effect sequence data.

[0146] In the embodiments of the present invention, first, according to the temperature change trend data, combined with the physical structure and thermal distribution characteristics of the circuit board, the circuit board is divided into multiple simulation regions. For example, the circuit board can be divided into a chip region, a heat dissipation hole region, a large current trace region, and other key thermally sensitive regions. The division basis for each region is its importance in the heat conduction and heat accumulation processes. For each simulation region, according to its initial temperature and heat flux density value, the initial heat accumulation amount is calculated. The initial heat accumulation amount can be determined in the following way: Assume that the heat accumulation amount in each region at the initial moment is zero, and then according to the heat flux density value and temperature value at the initial moment, combined with the heat capacity characteristics of the region, an initial heat accumulation amount is calculated. For example, for the chip region, the initial heat accumulation amount can be estimated by the product of the heat capacity of the chip and the initial temperature; According to the simulation accuracy requirements and computing resources, a suitable time step is selected. The selection range of the time step is from 1 ms to 100 ms. For the initial moment, the initial heat accumulation amount of each simulation region is assigned to the first time step. For example, if the selected time step is 10 ms, the initial heat accumulation amount is used as the starting heat accumulation amount of the first time step. During the assignment process, ensure that the heat accumulation amount in each region remains consistent within the time step, so as to serve as the starting point for the heat accumulation effect simulation. For example, for the chip region, its initial heat accumulation amount remains unchanged within the first 10 ms time step and serves as the initial condition for the heat accumulation effect simulation of this region; Within each time step, according to the temperature change rate and heat flux density change rate, the heat accumulation increment of each simulation region is calculated. The temperature change rate and heat flux density change rate can be obtained through differential processing. The specific operation is as follows: For each simulation region, according to its temperature change rate and heat flux density change rate, combined with the heat capacity and heat conduction coefficient of the region, the heat accumulation increment within this time step is calculated. For example, if the temperature change rate of a certain region is 0.1 °C / s, the heat flux density change rate is 0.05 W / m² / s, and the heat capacity is 1 J / °C, then the heat accumulation increment within this time step can be calculated by the product of the heat capacity and the temperature change rate. At the end of each time step, the calculated heat accumulation increment is accumulated into the current heat accumulation amount of the corresponding region, and the heat accumulation amount of this region is updated. For example, if the heat accumulation increment of a certain region within the current time step is 0.5 J and the current heat accumulation amount is 10 J, then the updated heat accumulation amount is 10.5 J; According to the selected time step, repeat the operation in step S463, gradually advancing the time step until the entire simulation time range is covered. Within each new time step, according to the latest temperature change rate and heat flux density change rate, recalculate the heat accumulation increment of each region and update the heat accumulation amount. For example, assume that the simulation time is 1 second and the time step is 10 ms, then 100 time steps of calculations are required.Within each time step, the heat accumulation increment is repeatedly calculated and the heat accumulation amount is updated until the entire 1-second simulation is completed; during the simulation, the heat accumulation amount and temperature value of each simulation area within each time step are recorded in real time. These data will form the sequence data of the heat accumulation effect. Based on the recorded sequence data of the heat accumulation effect, a thermal simulation model of the circuit board is constructed. Specifically, the sequence data of the heat accumulation effect is used as the input, and through data processing and analysis techniques, the key features of the heat accumulation are extracted, such as the change trend of the heat accumulation amount, the fluctuation of the temperature, etc. These features will be used to construct the thermal simulation model to simulate the thermal behavior of the circuit board under different operating conditions.

[0147] In this specification, a thermal simulation system for a circuit board is provided, which is used to execute the above-mentioned thermal simulation method for a circuit board. The thermal simulation system for a circuit board includes:

[0148] A circuit board layer data acquisition module, which is used to obtain circuit board layer data; extract the thermal resistance parameters of the board layer materials, including the thermal resistance parameters of the copper foil and the thermal resistance parameters of the insulating medium; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data;

[0149] A heat flux density distribution detection module, which is used to determine the component layout characteristics according to the hierarchical structure data, and calculate the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate the interlayer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the interlayer structure thermal resistance distribution data;

[0150] A circuit board heat interaction recognition module, which is used to calculate the joule heat value for the heat flux density distribution data based on the thermal resistance parameters of the foil and the thermal resistance parameters of the insulating medium; determine the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value to obtain the circuit board heat interaction data;

[0151] A circuit board heat accumulation effect simulation module, which is used to evaluate the change trend of the operating temperature of the circuit board based on the circuit board heat interaction data to generate the temperature change trend data; perform the circuit board heat accumulation effect simulation according to the temperature change trend data and construct the thermal simulation model of the circuit board.

[0152] The present invention obtains complete circuit board layer data through a circuit board layer data acquisition module, and accurately extracts the thermal resistance parameters of the board layer material and the delamination structure data; the heat flux density distribution detection module accurately calculates the interlayer thermal resistance distribution and heat flux density distribution data based on the delamination structure data and the component layout characteristics; the circuit board heat interaction recognition module further calculates the Joule heat value based on the heat flux density distribution data, determines the heat transfer interaction coefficient, and generates circuit board heat interaction data; the circuit board heat accumulation effect simulation module uses the heat interaction data to evaluate the trend of the operating temperature change and conducts a heat accumulation effect simulation, and finally constructs a high-precision circuit board thermal simulation model. The entire system can comprehensively and accurately simulate the thermal behavior of the circuit board, provide a reliable thermal simulation tool for the design optimization, performance evaluation, and fault prediction of the circuit board, and significantly improve the thermal management efficiency and reliability of the circuit board.

[0153] A computer-readable medium stores a computer program, wherein the computer program is used to execute the thermal simulation method for a circuit board described above.

[0154] Therefore, from any perspective, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to cover all changes falling within the meaning and scope of the equivalent elements of the application documents within the present invention.

[0155] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermal simulation method for a circuit board, characterized in that Including the following steps: Step S1: Obtain the circuit board layer data; extract the thermal resistance parameters of the board layer materials, including the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data; Step S2: Determine the component layout characteristics according to the hierarchical structure data, and perform an interlayer thermal resistance distribution calculation on the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the layer structure thermal resistance distribution data; Step S3: Perform a Joule heat value calculation on the heat flux density distribution data based on the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; determine the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the Joule heat value to obtain the circuit board heat interaction data; Step S4: Evaluate the trend of the operating temperature change of the circuit board based on the circuit board heat interaction data to generate temperature change trend data; Perform a circuit board heat accumulation effect simulation according to the temperature change trend data and construct a thermal simulation model of the circuit board.

2. The thermal simulation method for a circuit board according to claim 1, wherein Step S1 includes the following steps: Step S11: Obtain the structural parameters, material information, and connection point distribution information of the circuit board respectively to obtain the circuit board layer data; Step S12: Identify the copper foil layer and the insulating medium layer in the circuit board layer data, mark the boundary positions of the copper foil layer and the insulating medium layer, and extract the thermal resistance parameters of the copper foil layer and the insulating medium layer to obtain the thermal resistance parameters of the board layer materials; Step S13: Obtain the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters of the thermal resistance parameters of the board layer materials respectively; Step S14: Scan layer by layer from the circuit board layer data to determine the boundary range of each layer and mark it as the start and end points of each layer; the scanning speed is 10 layers per second, and the thickness accuracy of each layer is 0.001 mm; Step S15: Number each layer and record the layer numbers and the thicknesses of each layer in order from the outside to the inside; Step S16: For two adjacent layers, determine whether there is a connection relationship between the two adjacent layers and record the adjacent layer position connection relationship; Step S17: Integrate the start and end points of each layer, the layer numbers of each layer, the thicknesses of each layer, and the adjacent layer position connection relationship into hierarchical structure data.

3. The thermal simulation method for a circuit board according to claim 1, wherein In step S2, the determination of the component layout characteristics according to the hierarchical structure data and the interlayer thermal resistance distribution calculation based on the component layout characteristics for the thermal resistance parameters of the board layer materials include: Determine the component information of each layer from the hierarchical structure data and identify the boundary lines of the component information to obtain the component shape dimensions; Number the coordinates of the component shape dimensions, and mark the positions of the components in order from left to right and from top to bottom to generate component position coordinates; Determine the distance between adjacent components and the distance between the components and the edge of the circuit board according to the component position coordinates to obtain the component layout distance parameters; Integrate the component shape dimensions, the component position coordinates, and the component layout distance parameters into the component layout characteristics; Determine the heat resistance contribution area of components on the circuit board according to the component layout characteristics, and calculate the heat resistance values of the components in different board layers based on the heat resistance contribution area of the components; Between adjacent board layers, detect the heat resistance coupling area according to the component layout characteristics; calculate the interlayer heat resistance value of the coupling area between adjacent board layers based on the heat resistance coupling area to obtain the heat resistance distribution data of the layer structure.

4. The thermal simulation method for a circuit board according to claim 1, characterized in that, In step S2, detecting the interlayer via routing characteristics according to the component layout characteristics and calculating the heat flux density distribution data based on the interlayer via routing characteristics for the heat resistance distribution data of the layer structure includes: Determine the via requirements of components in different board layers according to the component layout characteristics, and determine the hole position distribution coordinates according to the via requirements; Detect the via setting conditions of the hole position distribution coordinates, including the aperture deviation and the via center offset; Detect the vertical alignment of vias between different board layers according to the aperture deviation to obtain the via vertical alignment; detect the offset amount of vias during interlayer penetration according to the via center offset to obtain the via interlayer offset; Judge the interlayer via routing relationship based on the via vertical alignment and the via interlayer offset to generate the interlayer via routing characteristics; Determine the via hole distribution density and the distance between holes according to the interlayer via routing characteristics; Identify the board heat flow path for the circuit board based on the via hole distribution density and the distance between holes, and divide the board heat flow path into a heat flow convergence area and a heat flow dispersion area; For the heat flow convergence area, calculate the heat flux density increase multiple of the circuit board according to the via hole distribution density and record the peak heat flux density of the area; For the heat flow dispersion area, calculate the heat flux uniformity coefficient of the circuit board according to the distance between holes and record the area heat flux uniformity coefficient; Perform heat flux density distribution measurement on the heat resistance distribution data of the layer structure based on the peak heat flux density of the area and the area heat flux uniformity coefficient to generate the heat flux density distribution data.

5. The thermal simulation method for a circuit board according to claim 1, wherein In step S3, calculating the joule heat value for the heat flux density distribution data based on the foil heat resistance parameter and the insulating medium heat resistance parameter includes: Determine the corresponding area of the copper foil heat resistance parameter and the insulating medium heat resistance parameter respectively to obtain the copper foil heat resistance area and the insulating medium heat resistance area; Perform area density ratio calculation on the heat flux density distribution data based on the copper foil heat resistance area and the insulating medium heat resistance area to obtain the heat flux density area ratio value; Calculate the joule heat of the copper foil heat resistance area and the insulating medium heat resistance area respectively according to the heat flux density area ratio value; and combine the joule heat of the copper foil heat resistance area and the insulating medium heat resistance area to generate the joule heat value.

6. The thermal simulation method for a circuit board according to claim 1, wherein In step S3, determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value includes: Calculate the joule heat ratio of the copper foil layer and the insulating medium layer according to the joule heat value to obtain the two-layer heat energy ratio; Determine the heat transfer direction between the copper foil layer and the insulating medium layer based on the two-layer heat energy ratio to generate the interlayer heat transfer direction; if the two-layer heat energy ratio is greater than or equal to 1, the heat transfer direction is from the copper foil layer to the insulating medium layer; if the two-layer heat energy ratio is less than 1, the heat transfer direction is from the insulating medium layer to the copper foil layer; Judge the heat transfer interaction coefficient through the interlayer heat transfer direction, and record the circuit board layer information corresponding to the heat transfer interaction coefficient to obtain the circuit board heat interaction data.

7. The thermal simulation method for a circuit board according to claim 1, wherein Step S4 includes the following steps: Step S41: Determine the interaction heat flux density value and interaction temperature value of the circuit board heat interaction data; Step S42: Extract the time characteristics corresponding to the interaction heat flux density value and interaction temperature, and perform chronological division to form time series data; Step S43: Perform differential processing on the time series data, calculate the heat flux density change amount and temperature change amount between adjacent time points to obtain the heat flux density change rate and temperature change rate, where the differential processing uses the five-point differential method and controls the error range within ±2%; Step S44: Evaluate the operating temperature change trend of the circuit board based on the heat flux density change rate and temperature change rate, and record the intensity value of the operating temperature change trend; Step S45: When the intensity values at three consecutive time points are all greater than 0.1 °C / s and the intensity value increase rate exceeds 10%, it is determined as an upward trend; when the intensity values at three consecutive time points are all less than -0.1 °C / s and the intensity value decrease rate exceeds 10%, it is determined as a downward trend; when the intensity values at three consecutive time points are all less than 0.1 °C / s and the intensity value volatility does not exceed 5%, it is determined as a stable trend; Step S46: Divide the intensity values into three types: upward trend, downward trend, and stable trend to generate temperature change trend data; Step S47: Perform circuit board heat accumulation effect simulation based on the temperature change trend data and construct a thermal simulation model of the circuit board.

8. The thermal simulation method for a circuit board according to claim 7, wherein Step S47 includes the following steps: Step S471: Divide the circuit board simulation area according to the temperature change trend data and set the initial heat accumulation amount for the circuit board simulation area; Step S472: Allocate the initial heat accumulation amount to each time step of each circuit board simulation area as the starting point of the heat accumulation effect simulation, where the time step range interval is from a minimum step of 1 ms to a maximum step of 100 ms; Step S473: Within each time step, calculate the heat accumulation increment of each area according to the temperature change rate; at the end of each time step, accumulate the heat accumulation increment of each area to the current heat accumulation amount of the corresponding area and update the heat accumulation amount of each area; Step S474: Repeat the above heat accumulation increment calculation and dynamic update steps, gradually advancing the time step until the entire simulation time range is covered; Step S475: During the simulation process, record the heat accumulation amount and temperature value of each time step to obtain the heat accumulation effect sequence data; construct a thermal simulation model of the circuit board according to the heat accumulation effect sequence data.

9. A thermal simulation system for a circuit board, characterized in that, For executing the thermal simulation method for a circuit board as described in claim 1, the thermal simulation system for the circuit board includes: A circuit board layer data acquisition module for acquiring circuit board layer data; extracting the board layer material thermal resistance parameters of the circuit board layer data, including copper foil thermal resistance parameters and insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data and recording it as hierarchical structure data; The heat flux density distribution detection module is used to determine the component layout characteristics according to the hierarchical structure data, and calculate the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer materials based on the component layout characteristics to generate the thermal resistance distribution data of the layer structure; detect the interlayer via wiring characteristics according to the component layout characteristics, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the thermal resistance distribution data of the layer structure; The printed circuit board heat interaction recognition module is used to calculate the joule heat value for the heat flux density distribution data based on the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter; determine the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer through the joule heat value to obtain the printed circuit board heat interaction data; The printed circuit board heat accumulation effect simulation module is used to evaluate the running temperature change trend of the printed circuit board based on the printed circuit board heat interaction data to generate the temperature change trend data; simulate the printed circuit board heat accumulation effect according to the temperature change trend data, and construct a thermal simulation model of the printed circuit board.

10. A computer-readable medium storing a computer program, characterized in that, When the computer program is executed, it implements the thermal simulation method for a printed circuit board according to any one of claims 1 to 8.

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