Thermal simulation method and system for circuit board and medium

Abstract

The invention relates to the technical field of data simulation processing, in particular to a thermal simulation method and system for a circuit board and a medium. The method comprises the following steps: acquiring circuit board layer data; extracting board layer material thermal resistance parameters of the circuit board layer data, wherein the board layer material thermal resistance parameters comprise copper foil thermal resistance parameters and insulating medium thermal resistance parameters; identifying the layered structure of the circuit board layer data, and recording as layered structure data; component layout characteristics are determined according to the layered structure data, interlayer thermal resistance distribution calculation is carried out on the board layer material thermal resistance parameters based on the component layout characteristics, and layered structure thermal resistance distribution data are generated. Through a data processing technology and an analogue simulation technology, heat transfer interaction analysis is carried out on the copper foil layer and the insulating medium layer of the circuit board, and the heat transfer direction and the heat accumulation effect of the circuit board are evaluated so as to construct a heat simulation model of the circuit board.

Description

Technical Field

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

[0002] As electronic devices develop towards miniaturization, high performance and high integration, the thermal management of printed circuit boards (PCBs) as the core carrier of electronic devices has become increasingly important. In modern electronic products, the power of electronic components continues to increase, and high-density packaging and assembly make the heat dissipation space smaller and smaller, resulting in a sharp increase in heat flux density. If the heat cannot be effectively managed and dissipated, the heat may cause the performance of components to deteriorate, the reliability to decrease, and even cause equipment failure or damage; traditional thermal simulation methods such as finite element method (FEM) and finite difference method (FDM) require the establishment of high-precision mesh models on the entire circuit board, especially in complex multi-layer circuit boards or areas around components, which not only requires a lot of computing resources, but also makes the simulation process very time-consuming. With the increase in the complexity of circuit boards, the demand for simulation time and computing resources has risen sharply. It is difficult for traditional methods to find a suitable balance between high precision and computational complexity; and the analysis of heat transfer interactions between different material layers inside the circuit board, especially the copper foil layer and the insulating medium layer, is not accurate enough, and it is difficult to accurately evaluate the heat transfer direction and heat 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 is provided, the method comprising the following steps: Step S1: obtaining circuit board layer data; extracting the board layer material thermal resistance parameters of the circuit board layer data, including the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data, and recording it as hierarchical structure data; Step S2: Determine the layout characteristics of the components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, 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: 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; Step S4: Evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data to generate temperature change trend data; simulate the heat accumulation effect of the circuit board based on the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0005] The present invention can accurately extract the thermal resistance parameters of copper foil and the thermal resistance parameters of insulating medium by acquiring the circuit board layer data, provide accurate basic data for subsequent thermal simulation calculations, and ensure the accuracy of subsequent thermal simulation analysis; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data, so that the structural characteristics of the circuit board can be clearly understood, and a clear structural basis is provided for the subsequent component layout feature analysis and interlayer thermal resistance distribution calculation based on the hierarchical structure; after determining the component layout characteristics according to the hierarchical structure data, the interlayer thermal resistance distribution calculation is performed on the thermal resistance parameters of the board layer material based on the characteristics, and the generated layer structure thermal resistance distribution data can accurately reflect the thermal resistance between the layers of the circuit board, and provide a reliable thermal resistance distribution basis for the subsequent calculation of the heat flux density distribution data; based on the component layout characteristics, the interlayer via wiring characteristics are detected, and the heat flux density distribution data is calculated based on the layer structure thermal resistance distribution data, which can accurately simulate the heat flux density of each area of ​​the circuit board in actual operation, and provide a basis for the subsequent Joule heat value The calculation provides accurate heat flux density information; the Joule heat value calculation of the heat flux density distribution data based on the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters can accurately obtain the Joule heat value generated by each part of the circuit board, providing accurate heat value data for the subsequent determination of the heat transfer interaction coefficient; the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer is determined by the Joule heat value, and the obtained circuit board thermal interaction data can truly reflect the heat transfer between different material layers inside the circuit board, providing key thermal interaction information for the subsequent evaluation of the operating temperature change trend; the operating temperature change trend of the circuit board is evaluated based on the circuit board thermal interaction data, and the generated temperature change trend data can accurately predict the temperature change of the circuit board under different operating conditions, providing an important reference for the thermal management and reliability evaluation of the circuit board; the heat accumulation effect of the circuit board is simulated according to the temperature change trend data, and a thermal simulation model of the circuit board is constructed. The model can comprehensively and accurately simulate the thermal behavior of the circuit board in actual operation. Therefore, the present invention uses data processing technology and simulation technology to realize heat transfer interaction analysis of the copper foil layer and the insulating medium layer of the circuit board, and evaluates the heat transfer direction and heat accumulation effect of the circuit board to construct a thermal simulation model of the circuit board.

[0006] Preferably, step S1 comprises the following steps: Step S11: respectively obtaining structural parameters, material information and connection point distribution information of the circuit board to obtain circuit board layer data; Step S12: Identify the copper foil layer and the insulating medium layer of the circuit board layer data, mark the boundary position 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 material; Step S13: respectively obtaining the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter of the board material thermal resistance parameter; Step S14: Scan the circuit board layer data layer by layer, determine the boundary range of each layer, and mark the starting and ending points of each layer; the scanning speed is 10 layers per second, and the thickness accuracy of each layer is 0.001mm; Step S15: number each layer, and record the layer number and thickness of each layer in order from outside to inside; Step S16: for two adjacent layers, determine whether the two adjacent layers have a connection relationship, and record the connection relationship between the adjacent layer positions; Step S17: Integrate the starting and ending points of each layer, the number of each layer, the thickness of each layer, and the position connection relationship of the adjacent layers into hierarchical structure data.

[0007] The present invention completely constructs the circuit board layer data by acquiring the structural parameters, material information and connection point distribution information of the circuit board, provides comprehensive and accurate basic information for subsequent thermal simulation analysis, and ensures that the thermal simulation process can be performed based on the complete circuit board characteristics; identifies the copper foil layer and the insulating medium layer of the circuit board layer data, marks the boundary position and extracts the thermal resistance parameters, realizes the accurate distinction and parameter acquisition of different material layers, and provides clear material boundaries and accurate thermal resistance parameters for subsequent thermal resistance distribution calculation; obtains the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters respectively, ensures the clear classification of the thermal resistance parameters, facilitates the subsequent targeted thermal simulation analysis for different material layers, and improves the accuracy and pertinence of the thermal simulation calculation; scans and marks layer by layer at a speed of 10 layers per second with a thickness accuracy of 0.001mm per layer The boundary range is recorded to achieve efficient and high-precision identification of each layer of the circuit board, ensuring the accuracy and reliability of the hierarchical structure data; each layer is numbered and the layer number and thickness are recorded, and they are sorted from the outside to the inside to establish a clear hierarchical structure order; the connection relationship between two adjacent layers is judged and the connection relationship between the adjacent layer positions is recorded, which clarifies the connection characteristics between layers and provides important connection information for the subsequent analysis of interlayer heat transfer and heat flow distribution, ensuring that the thermal simulation model can accurately reflect the structural characteristics of the actual circuit board; the starting and ending points of each layer, the layer number, the thickness of each layer and the connection relationship between the adjacent layer positions are integrated into the hierarchical structure data to form a complete and systematic hierarchical structure description, which provides a comprehensive and structured data foundation for the subsequent thermal simulation analysis based on the hierarchical structure, ensuring that the thermal simulation process can be carried out based on an accurate hierarchical structure.

[0008] Preferably, the step S2 of determining the layout characteristics of components according to the hierarchical structure data, and calculating the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer material based on the layout characteristics of the components includes: Determine the component information of each layer from the hierarchical structure data, and identify the boundary line of the component information to obtain the shape and size of the component; Number the shapes and sizes of components and mark the positions of components in order from left to right and from top to bottom to generate component position coordinates; Determine the spacing 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 component shape and size, component position coordinates, and component layout distance parameters into component layout features; Determine the thermal resistance contribution area of ​​components on the circuit board according to the layout characteristics of components, and calculate the thermal resistance values ​​of components in different board layers based on the thermal resistance contribution area of ​​components; Between adjacent board layers, the thermal resistance coupling area is detected according to the layout characteristics of the components; based on the thermal resistance coupling area, the interlayer thermal resistance value of the adjacent board layer coupling area is calculated to obtain the layer structure thermal resistance distribution data.

[0009] The present invention determines the component information of each layer from the hierarchical structure data and identifies the boundary line to obtain the shape and size of the component, which can accurately obtain the geometric features of the component, 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 component; coordinate numbering of the shape and size of the component, marking the position in order from left to right and from top to bottom, generating component position coordinates, achieving accurate positioning of the component on the board, providing clear coordinate information for subsequent analysis of the relative position relationship between the components, and improving the accuracy of the layout analysis; determining the spacing between adjacent components and the distance between the component and the edge of the circuit board according to the component position coordinates, obtaining the component layout distance parameter, and being able to quantify the spatial distribution relationship between the components, providing an important distance basis for the subsequent evaluation of the thermal impact and thermal resistance distribution between the components, and ensuring the accuracy of the thermal simulation analysis; the shape and size of the component, the position coordinates and the layout distance The parameters are integrated into the layout features of components, forming a comprehensive and systematic description of the component layout, which provides a complete and structured data basis for the subsequent thermal resistance calculation and heat flow analysis based on the layout features, ensuring that the thermal simulation process can be carried out based on accurate layout information; the thermal resistance contribution area of ​​the components on the circuit board is determined according to the layout features of the components, and its thermal resistance values ​​in different board layers are calculated, which can accurately identify the scope of influence of the components on the thermal performance of the circuit board and quantify its thermal resistance contribution, providing key thermal resistance data for the subsequent heat flux density distribution calculation and thermal simulation model construction, and improving the pertinence and accuracy of thermal simulation analysis; between adjacent board layers, the thermal resistance coupling area is detected according to the layout features of the components, and the interlayer thermal resistance value of the coupling area is calculated to obtain the layer structure thermal resistance distribution data, 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.

[0010] Preferably, the step S2 of detecting interlayer via wiring features according to component layout features, and calculating heat flux density distribution data from layer structure thermal resistance distribution data based on the interlayer via wiring features comprises: Determine the via requirements of components on different board layers based on the layout characteristics of components, and determine the hole distribution coordinates based on the via requirements; Detect the via hole setting of the hole distribution coordinates, including the aperture deviation and the via hole center offset; According to the aperture deviation, the vertical alignment of the vias between different board layers is detected to obtain the vertical alignment of the vias; according to the via center offset, the offset of the vias when penetrating between layers is detected to obtain the via interlayer offset; Determine the inter-layer via routing relationship based on the via vertical alignment and the via inter-layer offset to generate inter-layer via routing features; Determine the hole distribution density and the distance between holes of the vias according to the inter-layer via wiring characteristics; Based on the hole distribution density and the distance between holes, the heat flow path of the circuit board is identified, and the heat flow path of the circuit board is divided into a heat flow convergence area and a heat flow dispersion area; For the heat flux convergence area, calculate the heat flux density increase multiple of the circuit board according to the hole distribution density, and record the regional heat flux density peak value; For the heat flux dispersion area, calculate the heat flux uniformity coefficient of the circuit board according to the distance between holes, and record the regional heat flux uniformity coefficient; The heat flux distribution data of the layer structure thermal resistance distribution data is measured based on the regional heat flux peak value and the regional heat flux uniformity coefficient to generate heat flux distribution data.

[0011] The present invention determines the via requirements of components in different board layers according to the layout characteristics of components, and determines the hole distribution coordinates according to the via requirements, can accurately identify the electrical connection requirements of components, and clarify the specific positions of vias, provide accurate hole information for subsequent via wiring feature analysis, and ensure the coordination of electrical connection design and thermal simulation analysis of the circuit board; detect the via setting of the hole distribution coordinates, including the aperture deviation and the via center offset, can quantify the manufacturing accuracy of the via, provide key parameters for the subsequent analysis of the influence of the via on the heat flow path, and ensure that the thermal simulation model can truly reflect the actual thermal conduction characteristics of the via; detect the vertical alignment of the vias between different board layers according to the aperture deviation, and obtain the vertical alignment of the vias; detect the offset of the vias when penetrating between layers according to the via center offset, and obtain the via interlayer offset, which can accurately evaluate the alignment of the vias in the multi-layer circuit board, and provide accurate alignment and offset data for the subsequent judgment of the via wiring relationship between layers, and ensure the accuracy of the thermal simulation analysis; judge the via wiring relationship between layers based on the via vertical alignment and the via interlayer offset to generate the via wiring relationship between layers. The hole wiring characteristics can fully describe the connection status and heat conduction path of the vias between layers, and provide important wiring characteristic information for subsequent heat flow path identification and heat flux density distribution calculation; the hole distribution density and the distance between holes of the vias are determined according to the inter-layer via wiring characteristics, which can quantify the layout characteristics of the vias and ensure that the thermal simulation model can accurately reflect the influence of the vias on the heat flow; the heat flow path of the circuit board is identified based on the hole distribution density and the distance between holes, and the heat flow path of the board is divided into a heat flow convergence area and a heat flow dispersion area, which can clarify the heat flow distribution characteristics of the circuit board; for the heat flow convergence area, the heat flux density increase multiple of the circuit board is calculated according to the hole distribution density, and the regional heat flux density peak value is recorded, which can quantify the heat flux density change in the heat flow convergence area; for the heat flow dispersion area, the heat flux uniformity coefficient of the circuit board is calculated according to the distance between holes, and the regional heat flux uniformity coefficient is recorded, which can quantify the heat flux uniformity of the heat flow dispersion area; the heat flux density distribution of the layer structure thermal resistance distribution data is measured based on the regional heat flux density peak value and the regional heat flux uniformity coefficient, which can fully reflect the heat flux density of the circuit board in different areas.

[0012] Preferably, the calculation of 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 in step S3 includes: Determine the corresponding area by using the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter, and obtain the copper foil thermal resistance area and the insulating medium thermal resistance area; Based on the area of ​​the copper foil thermal resistance region and the area of ​​the insulating medium thermal resistance region, the area density ratio of the heat flux density distribution data is calculated to obtain the heat flux density area ratio value; The Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are calculated respectively according to the heat flux density area ratio; and the Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are combined to generate a Joule heat value.

[0013] The present invention determines the corresponding area of ​​the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter respectively, obtains the copper foil thermal resistance area area and the insulating medium thermal resistance area area, can clarify the distribution range of different materials in the heat flow path, and provide an accurate area basis for subsequent heat flux density distribution calculation; based on the copper foil thermal resistance area area and the insulating medium thermal resistance area area, the heat flux density distribution data is calculated to obtain the heat flux density area ratio value, which can quantify the contribution ratio of different areas to the heat flux density, and provide key area ratio data for subsequent Joule heat calculation; according to the heat flux density area ratio value, the Joule heat of the copper foil thermal resistance area area and the insulating medium thermal resistance area area are calculated respectively, and the Joule heat of the copper foil thermal resistance area area and the insulating medium thermal resistance area area are combined to generate the Joule heat value, which can comprehensively reflect the heat generation of the circuit board in different areas, and provide accurate heat data for the overall thermal performance evaluation of the circuit board.

[0014] Preferably, determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer by the Joule heat value in step S3 includes: The Joule heat ratio of the copper foil layer and the insulating dielectric layer is calculated based on the Joule heat value to obtain the heat energy ratio of the two layers; The heat transfer direction between the copper foil layer and the insulating medium layer is determined based on the heat energy ratio of the two layers to generate the interlayer heat transfer direction; if the heat 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 heat 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; The heat transfer interaction coefficient is determined by the heat transfer direction between layers, and the circuit board layer information corresponding to the heat transfer interaction coefficient is recorded to obtain the circuit board thermal interaction data.

[0015] The present invention calculates the Joule heat ratio of the copper foil layer and the insulating medium layer based on the Joule heat value to obtain the heat energy ratio of the two layers, which can quantify the heat distribution relationship between the copper foil layer and the insulating medium layer, and provide an accurate heat ratio basis for the subsequent determination of the heat transfer direction; the heat transfer direction between the copper foil layer and the insulating medium layer is determined based on the heat energy ratio of the two layers, and the heat transfer path between different material layers can be clarified. When the heat 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; when the heat 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. This result provides a clear directional basis for the judgment of the heat transfer interaction coefficient; the heat transfer interaction coefficient is judged by the heat transfer direction, and the circuit board layer information corresponding to the heat transfer interaction coefficient is recorded to obtain the circuit board thermal interaction data, which can fully reflect the heat transfer characteristics between different material layers inside the circuit board, and provide key thermal interaction parameters for the thermal simulation model of the circuit board.

[0016] Preferably, step S4 comprises the following steps: Step S41: determining the interactive heat flux density value and the interactive temperature value of the circuit board thermal interaction data; Step S42: extracting the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and dividing them in time sequence to form time series data; Step S43: performing differential processing on the time series data, calculating the heat flux density change and temperature change between adjacent time points, and obtaining the heat flux density change rate and temperature change rate, wherein the differential processing adopts a five-point differential method, and the error range is controlled within ±2%; Step S44: evaluating the operating temperature change trend of the circuit board according to the heat flux change rate and the temperature change rate, and recording 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 to be 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 to be a downward trend; when the intensity values ​​at three consecutive time points are all less than 0.1°C / s and the intensity value fluctuation rate does not exceed 5%, it is determined to be a stable trend; Step S46: Classify the intensity values ​​into three types: an upward trend, a downward trend, and a stable trend, to generate temperature change trend data; Step S47: simulating the heat accumulation effect of the circuit board according to the temperature change trend data, and constructing a thermal simulation model of the circuit board.

[0017] The present invention determines the interactive heat flux density value and interactive temperature value of the thermal interaction data of the circuit board, and can clarify the heat flow and temperature change 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; extracts the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and divides them in time sequence to form time series data, which can record the time dynamic characteristics of the thermal interaction process in an orderly manner, and provide structured time data for subsequent differential processing and trend analysis; differential processing is performed on the time series data, and the heat flux density change amount and temperature change amount between adjacent time points are calculated using the five-point differential method to obtain the heat flux density change rate and the temperature change rate, and the error range is controlled within ±2%, which can accurately quantify the dynamic change characteristics of the thermal interaction process, and provide structured time data for subsequent differential processing and trend analysis. The operating temperature change trend assessment provides high-precision change rate data; the operating temperature change trend of the circuit board is evaluated based on the heat flux density change rate and the temperature change rate, and the intensity value of the operating temperature change trend is recorded, which can fully reflect the temperature change dynamics of the circuit board during operation and provide a trend basis for the subsequent thermal accumulation effect simulation; the intensity value is divided into three types: rising trend, falling trend and stable trend to generate temperature change trend data, which can clearly describe the change pattern of the operating temperature of the circuit board and provide clear trend classification information for the construction of the thermal simulation model; the thermal accumulation effect of the circuit board is simulated according to the temperature change trend data, and the thermal simulation model of the circuit board is constructed, which can fully 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.

[0018] Preferably, step S47 includes the following steps: Step S471: dividing the circuit board simulation area according to the temperature change trend data, and setting the initial heat accumulation amount for the circuit board simulation area; Step S472: allocating 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, wherein the time step range interval is a minimum step of 1ms and a maximum step of 100ms; Step S473: in each time step, the heat accumulation increment of each region is calculated according to the temperature change rate; at the end of each time step, the heat accumulation increment of each region is added to the current heat accumulation amount of the corresponding region, and the heat accumulation amount of each region is updated; Step S474: repeat the above heat accumulation increment calculation and dynamic update steps, and gradually advance the time step until the entire simulation time range is covered; Step S475: During the simulation process, the heat accumulation amount and temperature value of each time step are recorded to obtain heat accumulation effect sequence data; and a thermal simulation model of the circuit board is constructed according to the heat accumulation effect sequence data.

[0019] The present invention divides the circuit board simulation area according to the temperature change trend data, and sets the initial heat accumulation amount for the circuit board simulation area, can reasonably divide the simulation area based on the temperature change characteristics, and provide clear initial conditions for the heat accumulation effect simulation, ensuring that the initial state of the thermal simulation model is consistent with the actual circuit board operation state; the initial heat accumulation amount is distributed to each time step of each circuit board simulation area as the starting point of the heat accumulation effect simulation, wherein the time step range interval is a minimum step of 1ms to a maximum step of 100ms, which can ensure the reasonable distribution of the initial heat accumulation amount within the simulation time, provide accurate time step control for the dynamic simulation of the heat accumulation effect, and ensure the simulation accuracy; within each time step, the heat accumulation increment of each area is calculated according to the temperature change rate; at the end of each time step, each The heat accumulation increment of the region is added to the current heat accumulation amount of the corresponding region, and the heat accumulation amount of each region is updated, which can reflect the heat accumulation changes of each region in real time and ensure the dynamic and accuracy of the heat accumulation effect simulation process; repeat the above heat accumulation increment calculation and dynamic update steps, and gradually advance the time step until the entire simulation time range is covered, which can fully simulate the heat accumulation effect of the circuit board during the entire operation process and ensure that the thermal simulation model can fully reflect the thermal behavior of the circuit board; during the simulation process, the heat accumulation amount and temperature value of each time step are recorded to obtain the heat accumulation effect sequence data; the thermal simulation model of the circuit board is constructed according to the heat accumulation effect sequence data, which can generate a high-precision thermal simulation model based on the detailed heat accumulation effect data, and provide a reliable simulation tool for the thermal performance evaluation and optimization of the circuit board.

[0020] 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: The circuit board layer data acquisition module is used to obtain circuit board layer data; extract the board layer material thermal resistance parameters of the circuit board layer data, 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; The heat flux density distribution detection module is used to determine the layout characteristics of components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, and calculate the heat flux density distribution data based on the layer structure thermal resistance distribution data based on the interlayer via wiring characteristics; The circuit board thermal interaction identification module is used to calculate the Joule heat value of the heat flux density distribution data based on the foil thermal resistance parameters and the insulating medium thermal resistance parameters; the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer is determined by the Joule heat value to obtain the circuit board thermal interaction data; The circuit board heat accumulation effect simulation module is used to evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data and generate temperature change trend data; simulate the circuit board heat accumulation effect according to the temperature change trend data and build a thermal simulation model of the circuit board.

[0021] The present invention obtains complete circuit board layer data through the circuit board layer data acquisition module, and accurately extracts the thermal resistance parameters of the board layer material and the layered 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 layered structure data and component layout characteristics; the circuit board thermal interaction identification module further calculates the Joule heat value based on the heat flux density distribution data, and determines the heat transfer interaction coefficient to generate the circuit board thermal interaction data; the circuit board thermal accumulation effect simulation module uses the thermal interaction data to evaluate the operating temperature change trend, and simulates the thermal accumulation effect, 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.

[0022] A computer readable medium stores a computer program, wherein the computer program is used to execute the thermal simulation method for a circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a step flow of a thermal simulation method for a circuit board; Figure 2 for Figure 1 Detailed implementation steps of step S4 in FIG. Figure 3 for Figure 2 Detailed implementation steps of step S46; The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The technical method of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In addition, the accompanying drawings are only schematic illustrations of the present invention and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying 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 implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor methods and / or microcontroller methods.

[0026] It should be understood that, although the terms "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are used only to distinguish one unit from another unit. For example, without departing from the scope of the exemplary embodiments, the first unit may be referred to as the second unit, and similarly the second unit may be referred to as the first unit. The term "and / or" used herein includes any and all combinations of one or more of the listed associated items.

[0027] To achieve this, please refer to Figures 1 to 3 , a thermal simulation method for a circuit board, the method comprising the following steps: Step S1: obtaining circuit board layer data; extracting the board layer material thermal resistance parameters of the circuit board layer data, including the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data, and recording it as hierarchical structure data; Step S2: Determine the layout characteristics of the components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, 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: 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; Step S4: Evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data to generate temperature change trend data; simulate the heat accumulation effect of the circuit board based on the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0028] The present invention can accurately extract the thermal resistance parameters of copper foil and the thermal resistance parameters of insulating medium by acquiring the circuit board layer data, provide accurate basic data for subsequent thermal simulation calculations, and ensure the accuracy of subsequent thermal simulation analysis; identify the hierarchical structure of the circuit board layer data and record it as hierarchical structure data, so that the structural characteristics of the circuit board can be clearly understood, and a clear structural basis is provided for the subsequent component layout feature analysis and interlayer thermal resistance distribution calculation based on the hierarchical structure; after determining the component layout characteristics according to the hierarchical structure data, the interlayer thermal resistance distribution calculation is performed on the thermal resistance parameters of the board layer material based on the characteristics, and the generated layer structure thermal resistance distribution data can accurately reflect the thermal resistance between the layers of the circuit board, and provide a reliable thermal resistance distribution basis for the subsequent calculation of the heat flux density distribution data; based on the component layout characteristics, the interlayer via wiring characteristics are detected, and the heat flux density distribution data is calculated based on the layer structure thermal resistance distribution data, which can accurately simulate the heat flux density of each area of ​​the circuit board in actual operation, and provide a basis for the subsequent Joule heat value The calculation provides accurate heat flux density information; the Joule heat value calculation of the heat flux density distribution data based on the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters can accurately obtain the Joule heat value generated by each part of the circuit board, providing accurate heat value data for the subsequent determination of the heat transfer interaction coefficient; the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer is determined by the Joule heat value, and the obtained circuit board thermal interaction data can truly reflect the heat transfer between different material layers inside the circuit board, providing key thermal interaction information for the subsequent evaluation of the operating temperature change trend; the operating temperature change trend of the circuit board is evaluated based on the circuit board thermal interaction data, and the generated temperature change trend data can accurately predict the temperature change of the circuit board under different operating conditions, providing an important reference for the thermal management and reliability evaluation of the circuit board; the heat accumulation effect of the circuit board is simulated according to the temperature change trend data, and a thermal simulation model of the circuit board is constructed. The model can comprehensively and accurately simulate the thermal behavior of the circuit board in actual operation. Therefore, the present invention uses data processing technology and simulation technology to realize heat transfer interaction analysis of the copper foil layer and the insulating medium layer of the circuit board, and evaluates the heat transfer direction and heat accumulation effect of the circuit board to construct a thermal simulation model of the circuit board.

[0029] In the embodiment of the present invention, reference Figure 1 FIG. 1 is a schematic diagram of a step flow chart 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: Step S1: obtaining circuit board layer data; extracting the board layer material thermal resistance parameters of the circuit board layer data, including the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data, and recording it as hierarchical structure data; In an embodiment of the present invention, the designed PCB project file is opened using AltiumDesigner software. In the PCB editing interface, select "File>FabricationOutputs>GerberFiles" through the menu bar to enter the Gerber file export setting interface. In the setting interface, select the appropriate unit (usually inches) and format (such as 2:5), and ensure that all required layers (such as wire layer, solder mask layer, silk screen layer, etc.) are selected. Pay special attention to the fact that for multi-layer boards, it is necessary to ensure that the pads and connection information of the middle 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 "ProjectOutputsfor[project name]" folder under the specified project directory; extract the copper foil thickness information from the circuit board design file (such as the Gerber file or the project file of the PCB design software). The copper foil thickness is usually recorded in the material property field in microns (μm). For example, in AltiumDesigner, the thickness of each layer of copper foil can be viewed through the "Material Properties" panel; the thermal resistance of the copper foil is calculated based on the thickness, purity and thermal conductivity of the copper foil (usually the thermal conductivity of pure copper, about 398W / (m·K)), combined with the actual distribution area 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 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 characteristic parameter, which can usually be found in the material database. For example, the thermal conductivity of FR-4 material is about 0.3W / (m·K); the thermal resistance of the insulating medium is calculated based on the thickness and thermal conductivity of the insulating medium, combined with its distribution area in the circuit board. 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, the lower the thermal conductivity and the higher the thermal resistance. The layered structure of the circuit board is analyzed using the layered recognition function of the circuit board design software. The software reads the layer information in the Gerber file and identifies the layers of the circuit board, such as the top layer (TopLayer), the bottom layer (BottomLayer), the middle signal layer (MidLayer), the power layer (PowerLayer) and the 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 the layers. For example, by checking the alignment marks and connection holes between the layers, the accuracy of the inter-layer connection can be confirmed. After the recognition is completed, the software records the layered structure information in a data format to form layered structure data.

[0030] Step S2: Determine the layout characteristics of the components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, and calculate the heat flux density distribution data based on the interlayer via wiring characteristics for the layer structure thermal resistance distribution data; In an embodiment of the present invention, a professional circuit board design software (such as Altium Designer or Cadence) is used to open the hierarchical structure file (such as a Gerber file or an ODB++ file) of the circuit board. Through the layout analysis function of the software, the layout information of the components is extracted, including the type, size, position 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), board layer number, etc.; the thermal conductivity and thickness parameters of each layer of material are obtained from the material specification of the circuit board. For example, for common multi-layer circuit boards, the inner layer usually uses glass fiber reinforced epoxy resin (FR-4), which has a thermal conductivity of 0.3 W / m·K and a thickness of 0.5 mm. According to these parameters, combined with the layout characteristics of components, the interlayer thermal resistance distribution calculation is performed on the thermal resistance parameters of the board layer material; the thermal conductivity and thickness parameters of each layer of material are read from the material specification; for each area where the component is located, the thermal resistance of the area is calculated based on its projected area on the board layer, combined with the thermal conductivity and thickness of the material. After the calculation is completed, the thermal resistance value of each area is stored as the layer structure thermal resistance distribution data to form a two-dimensional array, and each element of the array corresponds to the thermal resistance value of a region; use the circuit board design software to open the drilling file and extract the position coordinates (X, Y), diameter and connected layer pair information of the via. 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 the via number, center coordinates (X, Y), diameter, connected layer pair number, etc.; for each via, the thermal resistance of the via is calculated based on its diameter and the connected layer pair spacing, combined with the thermal conductivity of the material. After the calculation is completed, the thermal resistance value of the via is stored as the via thermal resistance distribution data to form a two-dimensional array, and each element of the array corresponds to the thermal resistance value of a via; the heat flow of each area and via is calculated based on the temperature difference and thermal resistance. The temperature difference can be obtained by measurement or preset temperature conditions. The heat flow calculation process is to divide the temperature difference by the thermal resistance, and the result is the heat flow; based on the heat flow and the heat conduction area, the heat flux density of each area and via is calculated. The heat flux density calculation process is to divide the heat flow by the heat conduction area, and the result is the heat flux density; the calculated heat flux density value is distributed to each area and via to form a complete heat flux density distribution data. The heat flux density distribution data is also stored as a two-dimensional array.

[0031] Step S3: 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; In an embodiment of the present invention, first, the 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 and power-on time passing through the copper foil are obtained from the electrical design file of the circuit board. Next, the resistance value of the copper foil is calculated. According to the resistance law, the resistance value is equal to the resistivity multiplied by the length of the copper foil divided by the cross-sectional area of ​​the copper foil. 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, and the resistance value of each segment is calculated separately, and then the resistance values ​​of all small segments are added to obtain the total resistance value of the entire copper foil; then, the Joule heat value is calculated 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 multiplied by the power-on time. The calculated Joule heat value will be used as a heat source for subsequent heat transfer analysis. After that, the heat transfer interaction coefficient between the copper foil layer and the insulating dielectric layer is determined. The Joule heat value is combined with the thermal resistance of the copper foil layer and the thermal resistance of the insulating dielectric layer, and the heat transfer interaction coefficient is calculated by numerical methods. The finite difference method is used for calculation, and the copper foil layer and the insulating dielectric layer are divided into multiple small units. The heat flux density is calculated according to the thermal resistance of each unit and the temperature difference between adjacent units. The heat transfer interaction coefficient of each unit is calculated according to the heat flux density and unit area; the heat transfer interaction coefficient of all units is weighted averaged to obtain the heat transfer interaction coefficient of the entire circuit board; in 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 temperature of the copper foil layer and the insulating dielectric layer. According to the actual working environment and initial state of the circuit board, the specific values ​​of the boundary conditions and initial conditions are determined. Finally, the calculated heat transfer interaction coefficient is combined with the Joule heat value to obtain the thermal interaction data of the circuit board. These data include information such as heat flux density and temperature distribution between the copper foil layer and the insulating dielectric layer, which can be used for subsequent thermal simulation analysis. The thermal interaction data is output in the form of a table or graph.

[0032] Step S4: Evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data to generate temperature change trend data; simulate the heat accumulation effect of the circuit board based on the temperature change trend data, and construct a thermal simulation model of the circuit board.

[0033] In an embodiment of the present invention, the running temperature change trend of the circuit board is evaluated based on the thermal interaction data of the circuit board. The key parameters of the temperature change are extracted from the thermal interaction data, including the temperature value, the timestamp and the corresponding heat flux density distribution. These data are imported into the thermal analysis software (such as ANSYS or Icepak), and the time step is set to a suitable value in the range of 1ms to 100ms to ensure the simulation accuracy and calculation efficiency. In the software, the temperature change trend in each time step is calculated according to the temperature change rate and the time step. The specific operation is to multiply the temperature change rate by the time step to obtain the temperature change in each time step, and then add these changes 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 tables or graphs for subsequent analysis. Then, the thermal accumulation effect of the circuit board is simulated according to the temperature change trend data. In the thermal analysis software, the initial heat accumulation is set to zero or a reasonable initial value is set according to the actual working conditions. In each time step, the heat accumulation increment of each area is calculated according to the heat flux density distribution data and the temperature change trend. The specific operation is to multiply the heat flux density by the time step to obtain the heat accumulation increment of each area within the time step. These heat accumulation increments are added to the initial heat accumulation to obtain the heat accumulation at the end of each time step. Repeat the above steps and gradually advance the time step until the entire simulation time range is covered. During the simulation process, the heat accumulation and temperature values ​​of each time step are recorded to form the heat accumulation effect sequence data. Finally, the thermal simulation model of the circuit board is constructed based on the heat accumulation effect sequence data. The heat accumulation effect sequence data is imported into the thermal simulation software, and the key features of heat accumulation, such as the change trend of heat accumulation and temperature fluctuation, are extracted through data processing and analysis technology. These features will be used to construct a thermal simulation model to simulate the thermal behavior of the circuit board under different operating conditions. When constructing the model, the initial conditions, boundary conditions, and material properties of the model are set according to the heat accumulation effect sequence data. The model is solved by methods such as finite element analysis (FEA) or computational fluid dynamics (CFD) to obtain the thermal distribution and temperature changes of the circuit board.

[0034] Preferably, step S1 comprises the following steps: Step S11: respectively obtaining structural parameters, material information and connection point distribution information of the circuit board to obtain circuit board layer data; Step S12: Identify the copper foil layer and the insulating medium layer of the circuit board layer data, mark the boundary position 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 material; Step S13: respectively obtaining the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter of the board material thermal resistance parameter; Step S14: Scan the circuit board layer data layer by layer, determine the boundary range of each layer, and mark the starting and ending points of each layer; the scanning speed is 10 layers per second, and the thickness accuracy of each layer is 0.001mm; Step S15: number each layer, and record the layer number and thickness of each layer in order from outside to inside; Step S16: for two adjacent layers, determine whether the two adjacent layers have a connection relationship, and record the connection relationship between the adjacent layer positions; Step S17: Integrate the starting and ending points of each layer, the number of each layer, the thickness of each layer, and the position connection relationship of the adjacent layers into hierarchical structure data.

[0035] In an embodiment 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. The optical measuring instrument is used to obtain the structural parameters of the circuit board, such as the size, number of layers, and line width; 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 the connection points. Combined with the design files 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.). This information is integrated into the circuit board layer data and stored in the database for subsequent processing; the circuit board layer data is analyzed by image processing technology. The edge detection algorithm, such as the Canny edge detection algorithm, is used to identify the boundary position between the copper foil layer and the insulating medium layer. After identifying the boundary, the thermal resistance parameters of the copper foil layer and the insulating medium layer are calculated by the finite element analysis method according to Fourier's law of heat conduction. The thermal resistance values ​​of the copper foil layer and the insulating medium layer are calculated by 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; the thermal resistance parameters of the copper foil layer and the insulating medium layer are extracted from the stored thermal resistance parameters of the board layer material. 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 respectively; 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 equipment is set to 0.001mm per layer thickness to ensure that the boundary range of each layer can be accurately identified. After the scan is completed, the starting point and the ending point of each layer are marked according to the scan data, and this information is stored as the starting and ending point data of each layer; each layer of the circuit board is numbered according to the order from the outside to the inside. The numbering starts from the outermost layer and proceeds inward in sequence to ensure the uniqueness and order of the numbering. At the same time, combined with the starting and ending point data of each layer obtained in step S14, the thickness of each layer is calculated, and the number and thickness information of each layer are stored in the database; the image recognition technology is used to analyze the distribution of the connection points between two adjacent layers. By identifying vias or other connection structures, it is determined whether there is an electrical connection relationship between two adjacent layers. If there is a connection relationship, the numbers of the two adjacent layers and the position information of the connection points are recorded and stored as the adjacent layer position connection relationship data; the starting and ending point data of each layer obtained in step S14, the 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, this information is integrated into a complete hierarchical structure data file for subsequent circuit board thermal simulation analysis.

[0036] Preferably, the step S2 of determining the layout characteristics of components according to the hierarchical structure data, and calculating the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer material based on the layout characteristics of the components includes: Determine the component information of each layer from the hierarchical structure data, and identify the boundary line of the component information to obtain the shape and size of the component; Number the shapes and sizes of components and mark the positions of components in order from left to right and from top to bottom to generate component position coordinates; Determine the spacing 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 component shape and size, component position coordinates, and component layout distance parameters into component layout features; Determine the thermal resistance contribution area of ​​components on the circuit board according to the layout characteristics of components, and calculate the thermal resistance values ​​of components in different board layers based on the thermal resistance contribution area of ​​components; Between adjacent board layers, the thermal resistance coupling area is detected according to the layout characteristics of the components; based on the thermal resistance coupling area, the interlayer thermal resistance value of the adjacent board layer coupling area is calculated to obtain the layer structure thermal resistance distribution data.

[0037] In an embodiment of the present invention, the hierarchical structure data is analyzed using image processing technology. The boundary line of the component is identified by an edge detection algorithm (such as the Canny algorithm) to determine the shape and size of the component. In the identification process, the layout information of the component, such as its approximate position and direction on the board, is combined to further accurately identify the boundary line. For example, for a rectangular component, its four corner points are identified and its length and width are calculated; for a circular component, its center and radius are identified. The identified component shape and size information is stored as component shape and size data; according to the shape and size data of the component, combined with the overall size and layout direction of the circuit board, the components are numbered and marked with a coordinate system. With the upper left corner of the circuit board as the coordinate origin, the horizontal direction is the X axis, the vertical direction is the Y axis, and the coordinate numbers are assigned to each component in order from left to right and from top to bottom. 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, the horizontal and vertical spacing between them is obtained. At the same time, the distance between each component and the edge of the circuit board is calculated, including the distance from the top, bottom, left, and right edges. For example, for the component located at the coordinate (3,2), the distance from the left boundary of the circuit board is 3 unit lengths, and the 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 size data, component position coordinate data, and component layout distance parameter data are integrated. Through data fusion technology, this information is arranged in the order of component numbers to form a complete component layout feature data file. This file contains the shape size, position coordinates, and distance information from adjacent components and the edge of the circuit board of each component, providing basic data for subsequent thermal resistance calculations; according to the component layout feature data, the thermal resistance contribution area of ​​each component in different board layers is determined. The thermal resistance contribution area refers to the range of thermal resistance influence of components on the surrounding area during heat conduction. For each component, the finite element analysis method is used to calculate its thermal resistance value in different board layers based on its shape, size and position coordinates, combined with the thermal conductivity and thickness of the circuit board material. For example, for a rectangular component located on the top layer, the calculated thermal resistance value is stored as the component thermal resistance contribution data; the thermal resistance coupling area between adjacent board layers is detected using the component layout feature data. The thermal resistance coupling area refers to the area where the thermal resistance between adjacent board layers affects each other due to the layout of components. The boundary of the coupling area is determined by analyzing the position coordinates and shape and size of the component.In the coupling area, the multi-physics field coupling calculation method is used to calculate the interlayer thermal resistance between adjacent board layers by considering the influence of contact thermal resistance; for the coupling area between two adjacent board layers, the calculated interlayer thermal resistance value is stored as layer structure thermal resistance distribution data.

[0038] Preferably, the step S2 of detecting interlayer via wiring features according to component layout features, and calculating heat flux density distribution data from layer structure thermal resistance distribution data based on the interlayer via wiring features comprises: Determine the via requirements of components on different board layers based on the layout characteristics of components, and determine the hole distribution coordinates based on the via requirements; Detect the via hole setting of the hole distribution coordinates, including the aperture deviation and the via hole center offset; According to the aperture deviation, the vertical alignment of the vias between different board layers is detected to obtain the vertical alignment of the vias; according to the via center offset, the offset of the vias when penetrating between layers is detected to obtain the via interlayer offset; Determine the inter-layer via routing relationship based on the via vertical alignment and the via inter-layer offset to generate inter-layer via routing features; Determine the hole distribution density and the distance between holes of the vias according to the inter-layer via wiring characteristics; Based on the hole distribution density and the distance between holes, the heat flow path of the circuit board is identified, and the heat flow path of the circuit board is divided into a heat flow convergence area and a heat flow dispersion area; For the heat flux convergence area, calculate the heat flux density increase multiple of the circuit board according to the hole distribution density, and record the regional heat flux density peak value; For the heat flux dispersion area, calculate the heat flux uniformity coefficient of the circuit board according to the distance between holes, and record the regional heat flux uniformity coefficient; The heat flux distribution data of the layer structure thermal resistance distribution data is measured based on the regional heat flux peak value and the regional heat flux uniformity coefficient to generate heat flux distribution data.

[0039] In an embodiment of the present invention, by analyzing the layout feature data of components and combining the electrical connection requirements of the circuit board, the via requirements of components between different board layers are determined. Professional PCB design software (such as Altium Designer or Cadence) is used to plan the location of the via according to the pin distribution and connection path of the components. During the design process, a suitable via diameter is selected according to the wiring density and current carrying capacity of the circuit board, which is usually not less than 0.3 mm. The hole distribution coordinates of the via are generated by the automatic layout function of the software and stored as hole distribution coordinate data; the vias in the hole distribution coordinates are detected by high-precision optical detection equipment or X-ray detection equipment. The detection equipment measures the actual aperture of each via through image recognition technology, compares it with the design value, and calculates the aperture deviation. At the same time, the offset between the center of the via and the design coordinates is detected to obtain the via center offset. The detection accuracy should reach ±0.01 mm to ensure the accuracy of the measurement results; the via images of different board layers are superimposed and compared through the stacking alignment detection technology of the multi-layer circuit board. Using image processing algorithms, calculate the vertical alignment of vias between different board layers, that is, the deviation of the via center in the vertical direction. At the same time, according to the via center offset, detect the horizontal offset of the via when it penetrates between layers. The detection results of vertical alignment and interlayer offset will be used for subsequent wiring relationship judgment; according to the detection results of via vertical alignment and interlayer offset, judge the wiring relationship of vias between different board layers. If the vertical alignment and interlayer offset are both within the design allowable range (usually ±0.05mm), it is considered that the via wiring relationship is good; otherwise, the via needs to be readjusted or repaired. The wiring relationship information of the via is stored as interlayer via wiring feature data; by analyzing the interlayer via wiring feature data, calculate the distribution density of the via and the distance between holes. 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 holes refers to the distance between the centers of adjacent vias, which is obtained by measurement and calculation. According to the via distribution density and the distance between holes, the wiring density and heat dissipation performance of the circuit board are evaluated; the heat flow path of the circuit board is identified by using thermal flow analysis software (such as FloTHERM or ANSYS Icepak) combined with the via distribution density and the distance between holes data. According to the distribution of heat flux 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 with dense via distribution and high heat flux density; the heat flow dispersion area refers to the area with sparse via distribution and low heat flux density; in the heat flow convergence area, the increase multiple of the heat flux density is calculated by analyzing the hole distribution density. The heat flux density increase multiple refers to the ratio of the heat flux density in the heat flow convergence area to the average heat flux density. At the same time, the peak heat flux density in the heat flow convergence area is recorded to evaluate the heat dissipation requirements of the area; in the heat flow dispersion area, the heat flux uniformity coefficient is calculated by analyzing the distance between holes.The heat flux uniformity coefficient reflects the uniformity of heat flux distribution. The smaller the coefficient, the more uniform the heat flux distribution. The heat flux uniformity coefficient of the heat flux dispersion area is recorded to evaluate the heat dissipation uniformity of the area. According to the heat flux density peak value of the heat flux convergence area and the heat flux uniformity coefficient of the heat flux dispersion area, the heat flux density distribution of the layer structure thermal resistance distribution data is measured. The heat flux density distribution data is generated by thermal simulation software, which reflects the heat flux density of the circuit board in different areas.

[0040] Preferably, the calculation of 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 in step S3 includes: Determine the corresponding area by using the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter, and obtain the copper foil thermal resistance area and the insulating medium thermal resistance area; Based on the area of ​​the copper foil thermal resistance region and the area of ​​the insulating medium thermal resistance region, the area density ratio of the heat flux density distribution data is calculated to obtain the heat flux density area ratio value; The Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are calculated respectively according to the heat flux density area ratio; and the Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are combined to generate a Joule heat value.

[0041] In an embodiment of the present invention, a professional PCB design software (such as Altium Designer or Cadence) is used to divide the copper foil layer and the insulating medium layer into regions in combination with the hierarchical structure data and component layout features of the circuit board. Through the automatic layout function of the software, the distribution areas of the copper foil layer and the insulating medium layer are identified, and the respective regional areas are calculated. In the specific operation, the hierarchical structure data of the circuit board is first imported, and then the regional analysis tool of the software is used to calculate the copper foil thermal resistance area area and the insulating medium thermal resistance area area respectively according to the boundary information of the copper foil layer and the insulating medium layer; according to the copper foil thermal resistance area area and the insulating medium thermal resistance area area, combined with the heat flux density distribution data, the area density ratio is calculated. The specific operation is: the copper foil thermal resistance area area and the insulating medium thermal resistance area area are divided 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 and these area ratios are weightedly calculated to obtain the heat flux density area ratio value. This process can be completed through thermal simulation software (such as FloTHERM or ANSYS Icepak). The software will automatically generate the heat flux area ratio value based on the input area and heat flux density data; using the heat flux area ratio value, combined with the power consumption data of the circuit board, the Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are calculated respectively. The specific operation is: according to the heat flux area ratio value, the total power consumption of the circuit board is allocated to the copper foil thermal resistance area and the insulating medium thermal resistance area. For example, if the heat flux area ratio of the copper foil thermal resistance area is 60%, the heat flux area ratio of the insulating medium thermal resistance area is 40%, and the total power consumption of the circuit board is 10W, then the Joule heat of the copper foil thermal resistance area is 6W, and the Joule heat of the insulating medium thermal resistance area is 4W. Finally, the Joule heat of these two areas is combined to generate the total Joule heat value of the circuit board.

[0042] Preferably, determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer by the Joule heat value in step S3 includes: The Joule heat ratio of the copper foil layer and the insulating dielectric layer is calculated based on the Joule heat value to obtain the heat energy ratio of the two layers; The heat transfer direction between the copper foil layer and the insulating medium layer is determined based on the heat energy ratio of the two layers to generate the interlayer heat transfer direction; if the heat 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 heat 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; The heat transfer interaction coefficient is determined by the heat transfer direction between layers, and the circuit board layer information corresponding to the heat transfer interaction coefficient is recorded to obtain the circuit board thermal interaction data.

[0043] In an embodiment of the present invention, in a thermal simulation software (such as ANSYS Icepak), the thermal simulation result data of the circuit board is imported to extract the Joule heat value of the copper foil layer and the insulating dielectric layer. The specific operation is: 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 value of the copper foil layer and the insulating dielectric layer according to the input data. Subsequently, through the "parameter calculation" function of the software, the Joule heat value of the copper foil layer is divided by the Joule heat value of the insulating dielectric layer to obtain the heat energy ratio of the two layers; in the ANSYS Icepak software, the heat transfer direction is determined according to the calculated heat energy ratio of the two layers. The specific operation is: in the "heat transfer direction judgment" module, input the heat energy ratio of the two layers. If the Joule heat ratio is greater than or equal to 1, the software automatically marks the heat transfer direction as "copper foil layer to insulating dielectric layer"; if the Joule heat ratio is less than 1, it is marked as "insulating dielectric layer to copper foil layer". The software will output and save the judgment results in the form of "interlayer heat transfer direction" data; in ANSYS Icepak software, the heat transfer interaction coefficient is further calculated according to the interlayer heat transfer direction. The specific operation is: in the "heat transfer interaction coefficient calculation" module, input the interlayer heat transfer direction data and the material properties of the copper foil layer and the insulating medium layer (such as thermal conductivity, specific heat capacity, etc.). The software will automatically calculate the heat transfer interaction coefficient based on these parameters and 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.

[0044] As an example of the present invention, refer to Figure 2 As shown, in this example, step S4 includes: Step S41: determining the interactive heat flux density value and the interactive temperature value of the circuit board thermal interaction data; Step S42: extracting the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and dividing them in time sequence to form time series data; Step S43: performing differential processing on the time series data, calculating the heat flux density change and temperature change between adjacent time points, and obtaining the heat flux density change rate and temperature change rate, wherein the differential processing adopts a five-point differential method, and the error range is controlled within ±2%; Step S44: evaluating the operating temperature change trend of the circuit board according to the heat flux change rate and the temperature change rate, and recording 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 to be 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 to be a downward trend; when the intensity values ​​at three consecutive time points are all less than 0.1°C / s and the intensity value fluctuation rate does not exceed 5%, it is determined to be a stable trend; Step S46: Classify the intensity values ​​into three types: an upward trend, a downward trend, and a stable trend, to generate temperature change trend data; Step S47: simulating the heat accumulation effect of the circuit board according to the temperature change trend data, and constructing a thermal simulation model of the circuit board.

[0045] In an embodiment of the present invention, a high-precision heat flux sensor array is attached to the key thermal interaction areas of the circuit board, including the connection between the chip and the substrate, near the heat dissipation holes, and the high-current routing area. The sensor array consists of multiple high-precision heat flux sensors, each of which has a measurement range of 0~1000 W / m², an accuracy of ±0.1 W / m², and a sampling frequency of 100Hz. At the same time, a high-precision temperature sensor is arranged at the same position, with a measurement range of -50~200℃, an accuracy of ±0.05℃, and a sampling frequency of 100 Hz; the signals of the heat flux sensor and the temperature sensor are synchronously collected through a data acquisition card. The data acquisition card has a multi-channel input function, which can simultaneously receive the signals of the heat flux sensor and the temperature sensor, and amplify and filter them. The filtering process 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 parses and stores the received data, and finally obtains the interactive heat flux density value and interactive temperature value of the thermal interaction data of the circuit board; the interactive heat flux density value and interactive temperature value obtained in step S41 are extracted from the data processing system. Each data point is accompanied by a timestamp, and the timestamp is in seconds, accurate to three decimal places. The data processing system pairs the heat flux density value and temperature value corresponding to each time point to form a triple data structure containing a timestamp, a heat flux density value and a temperature value. For example, the data structure at a certain time point is (timestamp, heat flux density value, temperature value). Arrange all paired data in order from small to large timestamps. During the arrangement process, the system will check the continuity of the timestamp to ensure that the data is arranged in chronological order. If the timestamp is found to be 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, in which each data point contains a corresponding timestamp, heat flux value and temperature value; the time series data formed in step S42 is input into the differential processing module. The differential processing module uses the five-point differential method to process the data. The five-point differential method is a differential 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 third data point to the third to last data point), the differential processing module first extracts the heat flux value and temperature value of the data point and its first two and last two data points. Then, according to the rules of the five-point differential method, the heat flux change rate and temperature change rate of the data point are calculated. The specific operation is as follows: Heat flux change rate calculation: The differential processing module performs weighted calculation on the heat flux values ​​of the current data point and its two data points before and after it to obtain the heat flux change rate of the current data point. The weighting coefficient is pre-set according to the rules of the five-point differential method to ensure that the calculation result can reflect the changing trend of the heat flux at this time point.Temperature change rate calculation: Similarly, the differential processing module performs weighted calculation on the temperature values ​​of the current data point and the two data points before and after it to obtain the temperature change rate of the current data point. The weighting coefficient is the same as the calculation of the heat flux change rate, ensuring that the temperature change rate can accurately reflect the temperature change trend at that time point. Comprehensively analyze the heat flux change rate and temperature change rate at each time point, and judge the trend: When the heat flux change rate and the temperature change rate are both positive values, the circuit board is judged to be in a heating trend at that moment. When the heat flux change rate and the temperature change rate are both negative values, the circuit board is judged to be in a cooling trend at that moment. When the absolute values ​​of the heat flux change rate and the temperature change rate are both less than the preset threshold (for example, 0.01 W / m² / s and 0.01℃ / s), the circuit board is judged to be in a stable trend at that moment. Intensity value calculation: For each time point, the trend evaluation module comprehensively processes the values ​​of the heat flux 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 that 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 get the final intensity value. When the intensity values ​​at three consecutive time points are greater than 0.1℃ / s and the intensity value increase rate exceeds 10%, it is determined to be an upward trend; when the intensity values ​​at three consecutive time points are less than -0.1℃ / s and the intensity value decrease rate exceeds 10%, it is determined to be a downward trend; when the intensity values ​​at three consecutive time points are less than 0.1℃ / s and the intensity value fluctuation rate does not exceed 5%, it is determined to be a stable trend; first, according to the temperature change trend data, determine the heat flow input and output of the circuit board in each time period. Heat flow input includes heat generated by the chip, heat from external heat sources, etc.; heat flow output includes heat dissipated through heat dissipation structures such as heat dissipation holes and heat sinks; the simulation module calculates the heat accumulation of the circuit board in each time period based on the difference between the heat flow input and output. The heat accumulation 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 with the temperature change trend data to simulate the temperature change process of the circuit board under different operating conditions.

[0046] As an example of the present invention, refer to Figure 3 As shown, in this example, step S47 includes: Step S471: dividing the circuit board simulation area according to the temperature change trend data, and setting the initial heat accumulation amount for the circuit board simulation area; Step S472: allocating 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, wherein the time step range interval is a minimum step of 1ms and a maximum step of 100ms; Step S473: in each time step, the heat accumulation increment of each region is calculated according to the temperature change rate; at the end of each time step, the heat accumulation increment of each region is added to the current heat accumulation amount of the corresponding region, and the heat accumulation amount of each region is updated; Step S474: repeat the above heat accumulation increment calculation and dynamic update steps, and gradually advance the time step until the entire simulation time range is covered; Step S475: During the simulation process, the heat accumulation amount and temperature value of each time step are recorded to obtain heat accumulation effect sequence data; and a thermal simulation model of the circuit board is constructed according to the heat accumulation effect sequence data.

[0047] In an embodiment of the present invention, first, according to the temperature change trend data, combined with the physical structure and heat distribution characteristics of the circuit board, the circuit board is divided into multiple simulation areas. For example, the circuit board can be divided into a chip area, a heat dissipation hole area, a high current routing area and other key heat-sensitive areas. The basis for the division of each area is its importance in the heat conduction and heat accumulation process. For each simulation area, the initial heat accumulation is calculated according to its initial temperature and heat flux density value. The initial heat accumulation can be determined in the following way: assuming that the heat accumulation of each area 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 area, an initial heat accumulation is calculated. For example, for the chip area, the initial heat accumulation can be estimated by multiplying the heat capacity of the chip by 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 1ms to 100ms. For the initial moment, the initial heat accumulation of each simulation area is allocated to the first time step. For example, if the selected time step is 10ms, the initial heat accumulation is used as the starting heat accumulation of the first time step. During the allocation process, ensure that the heat accumulation of each region remains consistent within the time step so that it can be used as the starting point for the simulation of the heat accumulation effect. For example, for the chip area, its initial heat accumulation remains unchanged within the first 10ms time step as the initial condition for the simulation of the heat accumulation effect in the area; in each time step, the heat accumulation increment of each simulation area is calculated based on the temperature change rate and the heat flux change rate. The temperature change rate and the heat flux change rate can be obtained by differential processing. The specific operation is as follows: For each simulation area, the heat accumulation increment within the time step is calculated based on its temperature change rate and heat flux change rate, combined with the heat capacity and thermal conductivity of the area. For example, if the temperature change rate of a region is 0.1℃ / s, the heat flux change rate is 0.05 W / m² / s, and the heat capacity is 1 J / ℃, the heat accumulation increment within the time step can be calculated by multiplying the heat capacity and the temperature change rate. At the end of each time step, the calculated heat accumulation increment is added to the current heat accumulation of the corresponding area, and the heat accumulation of the area is updated. For example, if the heat accumulation increment of a region in the current time step is 0.5 J and the current heat accumulation is 10 J, the updated heat accumulation is 10.5 J; according to the selected time step, repeat the operation of step S463, and gradually advance the time step until the entire simulation time range is covered. In each new time step, the heat accumulation increment of each region is recalculated and the heat accumulation is updated according to the latest temperature change rate and heat flux change rate. For example, assuming the simulation time is 1 second and the time step is 10 ms, 100 time steps need to be calculated.In 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 process, the heat accumulation amount and temperature value of each simulation area in each time step are recorded in real time. These data will form the heat accumulation effect sequence data. According to the recorded heat accumulation effect sequence data, the thermal simulation model of the circuit board is constructed. The specific operation is to use the heat accumulation effect sequence data as input, and extract the key features of heat accumulation, such as the change trend of heat accumulation amount, temperature fluctuation, etc. through data processing and analysis technology. These features will be used to build a thermal simulation model to simulate the thermal behavior of the circuit board under different operating conditions.

[0048] 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: The circuit board layer data acquisition module is used to obtain circuit board layer data; extract the board layer material thermal resistance parameters of the circuit board layer data, 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; The heat flux density distribution detection module is used to determine the layout characteristics of components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, and calculate the heat flux density distribution data based on the layer structure thermal resistance distribution data based on the interlayer via wiring characteristics; The circuit board thermal interaction identification module is used to calculate the Joule heat value of the heat flux density distribution data based on the foil thermal resistance parameters and the insulating medium thermal resistance parameters; the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer is determined by the Joule heat value to obtain the circuit board thermal interaction data; The circuit board heat accumulation effect simulation module is used to evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data and generate temperature change trend data; simulate the circuit board heat accumulation effect according to the temperature change trend data and build a thermal simulation model of the circuit board.

[0049] The present invention obtains complete circuit board layer data through the circuit board layer data acquisition module, and accurately extracts the thermal resistance parameters of the board layer material and the layered 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 layered structure data and component layout characteristics; the circuit board thermal interaction identification module further calculates the Joule heat value based on the heat flux density distribution data, and determines the heat transfer interaction coefficient to generate the circuit board thermal interaction data; the circuit board thermal accumulation effect simulation module uses the thermal interaction data to evaluate the operating temperature change trend, and simulates the thermal accumulation effect, 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.

[0050] A computer readable medium stores a computer program, wherein the computer program is used to execute the thermal simulation method for a circuit board.

[0051] Therefore, the embodiments should be regarded as illustrative and non-restrictive from all points, and the scope of the present invention is limited by the appended claims rather than the above description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the application documents are included in the present invention.

[0052] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may 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 the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

Claims

1. A thermal simulation method for a circuit board, characterized in that: The following steps are involved: Step S1: obtaining circuit board layer data; extracting the board layer material thermal resistance parameters of the circuit board layer data, including the copper foil thermal resistance parameters and the insulating medium thermal resistance parameters; identifying the hierarchical structure of the circuit board layer data, and recording it as hierarchical structure data; Step S2: Determine the layout characteristics of the components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, 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: 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; Step S4: evaluating the operating temperature change trend of the circuit board based on the circuit board thermal interaction data, and generating temperature change trend data; The heat accumulation effect of the circuit board is simulated based on the temperature change trend data, and a thermal simulation model of the circuit board is constructed.

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

3. The thermal simulation method for a circuit board according to claim 1, characterized in that: Determining the layout characteristics of components according to the hierarchical structure data in step S2, and calculating the interlayer thermal resistance distribution of the thermal resistance parameters of the board layer material based on the layout characteristics of the components, includes: Determine the component information of each layer from the hierarchical structure data, and identify the boundary line of the component information to obtain the shape and size of the component; Number the shapes and sizes of components and mark the positions of components in order from left to right and from top to bottom to generate component position coordinates; Determine the spacing 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 component shape and size, component position coordinates, and component layout distance parameters into component layout features; Determine the thermal resistance contribution area of ​​components on the circuit board according to the layout characteristics of components, and calculate the thermal resistance values ​​of components in different board layers based on the thermal resistance contribution area of ​​components; Between adjacent board layers, the thermal resistance coupling area is detected according to the layout characteristics of the components; based on the thermal resistance coupling area, the interlayer thermal resistance value of the adjacent board layer coupling area is calculated to obtain the layer structure thermal resistance distribution data.

4. The thermal simulation method for a circuit board according to claim 1, characterized in that: The step S2 of detecting the interlayer via wiring characteristics according to the component layout characteristics, and calculating the heat flux density distribution data based on the layer structure thermal resistance distribution data according to the interlayer via wiring characteristics includes: Determine the via requirements of components on different board layers based on the layout characteristics of components, and determine the hole distribution coordinates based on the via requirements; Detect the via hole setting of the hole distribution coordinates, including the aperture deviation and the via hole center offset; According to the aperture deviation, the vertical alignment of the vias between different board layers is detected to obtain the vertical alignment of the vias; according to the via center offset, the offset of the vias when penetrating between layers is detected to obtain the via interlayer offset; Determine the inter-layer via routing relationship based on the via vertical alignment and the via inter-layer offset to generate inter-layer via routing features; Determine the hole distribution density and the distance between holes of the vias according to the inter-layer via wiring characteristics; Based on the hole distribution density and the distance between holes, the heat flow path of the circuit board is identified, and the heat flow path of the circuit board is divided into a heat flow convergence area and a heat flow dispersion area; For the heat flux convergence area, calculate the heat flux density increase multiple of the circuit board according to the hole distribution density, and record the regional heat flux density peak value; For the heat flux dispersion area, calculate the heat flux uniformity coefficient of the circuit board according to the distance between holes, and record the regional heat flux uniformity coefficient; The heat flux distribution data of the layer structure thermal resistance distribution data is measured based on the regional heat flux peak value and the regional heat flux uniformity coefficient to generate heat flux distribution data.

5. The thermal simulation method for a circuit board according to claim 1, characterized in that: The Joule heat value calculation of the heat flux density distribution data based on the foil thermal resistance parameter and the insulating medium thermal resistance parameter in step S3 includes: Determine the corresponding area by using the copper foil thermal resistance parameter and the insulating medium thermal resistance parameter, and obtain the copper foil thermal resistance area and the insulating medium thermal resistance area; Based on the area of ​​the copper foil thermal resistance region and the area of ​​the insulating medium thermal resistance region, the area density ratio of the heat flux density distribution data is calculated to obtain the heat flux density area ratio value; The Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are calculated respectively according to the heat flux density area ratio; and the Joule heat of the copper foil thermal resistance area and the insulating medium thermal resistance area are combined to generate a Joule heat value.

6. The thermal simulation method for a circuit board according to claim 1, characterized in that: Determining the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer by the Joule heat value in step S3 includes: The Joule heat ratio of the copper foil layer and the insulating dielectric layer is calculated based on the Joule heat value to obtain the heat energy ratio of the two layers; The heat transfer direction between the copper foil layer and the insulating medium layer is determined based on the heat energy ratio of the two layers to generate the interlayer heat transfer direction; if the heat 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 heat 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; The heat transfer interaction coefficient is determined by the heat transfer direction between layers, and the circuit board layer information corresponding to the heat transfer interaction coefficient is recorded to obtain the circuit board thermal interaction data.

7. The thermal simulation method for a circuit board according to claim 1, characterized in that: Step S4 includes the following steps: Step S41: determining the interactive heat flux density value and the interactive temperature value of the circuit board thermal interaction data; Step S42: extracting the time characteristics corresponding to the interactive heat flux density value and the interactive temperature, and dividing them in time sequence to form time series data; Step S43: performing differential processing on the time series data, calculating the heat flux density change and temperature change between adjacent time points, and obtaining the heat flux density change rate and temperature change rate, wherein the differential processing adopts a five-point differential method, and the error range is controlled within ±2%; Step S44: evaluating the operating temperature change trend of the circuit board according to the heat flux change rate and the temperature change rate, and recording 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 to be 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 to be a downward trend; when the intensity values ​​at three consecutive time points are all less than 0.1°C / s and the intensity value fluctuation rate does not exceed 5%, it is determined to be a stable trend; Step S46: Classify the intensity values ​​into three types: an upward trend, a downward trend, and a stable trend, to generate temperature change trend data; Step S47: simulating the heat accumulation effect of the circuit board according to the temperature change trend data, and constructing a thermal simulation model of the circuit board.

8. The thermal simulation method for a circuit board according to claim 7, characterized in that: Step S47 includes the following steps: Step S471: dividing the circuit board simulation area according to the temperature change trend data, and setting the initial heat accumulation amount for the circuit board simulation area; Step S472: allocating 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, wherein the time step range interval is a minimum step of 1ms and a maximum step of 100ms; Step S473: in each time step, the heat accumulation increment of each region is calculated according to the temperature change rate; at the end of each time step, the heat accumulation increment of each region is added to the current heat accumulation amount of the corresponding region, and the heat accumulation amount of each region is updated; Step S474: repeat the above heat accumulation increment calculation and dynamic update steps, and gradually advance the time step until the entire simulation time range is covered; Step S475: During the simulation process, the heat accumulation amount and temperature value of each time step are recorded to obtain heat accumulation effect sequence data; and a thermal simulation model of the circuit board is constructed according to the heat accumulation effect sequence data.

9. A thermal simulation system for a circuit board, characterized in that: Used to perform the thermal simulation method for a circuit board as claimed in claim 1, the thermal simulation system for a circuit board comprises: The circuit board layer data acquisition module is used to obtain circuit board layer data; extract the board layer material thermal resistance parameters of the circuit board layer data, 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; The heat flux density distribution detection module is used to determine the layout characteristics of components according to the layered structure data, and calculate the interlayer thermal resistance distribution of the board material thermal resistance parameters based on the layout characteristics of the components to generate the layer structure thermal resistance distribution data; detect the interlayer via wiring characteristics according to the layout characteristics of the components, and calculate the heat flux density distribution data based on the layer structure thermal resistance distribution data based on the interlayer via wiring characteristics; The circuit board thermal interaction identification module is used to calculate the Joule heat value of the heat flux density distribution data based on the foil thermal resistance parameters and the insulating medium thermal resistance parameters; the heat transfer interaction coefficient between the copper foil layer and the insulating medium layer is determined by the Joule heat value to obtain the circuit board thermal interaction data; The circuit board heat accumulation effect simulation module is used to evaluate the operating temperature change trend of the circuit board based on the circuit board thermal interaction data and generate temperature change trend data; simulate the circuit board heat accumulation effect according to the temperature change trend data and build a thermal simulation model of the circuit board.

10. A computer readable medium storing a computer program, characterized in that: When the computer program is executed, the thermal simulation method for a circuit board as claimed in any one of claims 1 to 8 is implemented.

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