Stretchable flexible circuit board and its stress distribution optimization method

Abstract

The present invention relates to the field of material science, and discloses a stretchable flexible circuit board and a stress distribution optimization method thereof, including: defining the circuit board requirements of the circuit board, defining the island bridge structure of the circuit board, calculating the component integration coefficient of the circuit board island, and defining the corrugated structure of the circuit board bridge; analyzing the bridge characteristics and corrugated structure characteristics of the circuit board bridge and the corrugated structure, and constructing the microcrack structure of the circuit board bridge and the corrugated structure; establishing the surface microstructure of the circuit board island and the circuit board bridge, calculating the stress coordination coefficient of the surface microstructure to the corrugated structure and the microcrack structure, constructing the integrated circuit of the circuit board, and establishing a stretchable flexible circuit board of the circuit board; modularizing the integrated circuit to obtain a module integrated circuit, analyzing the stress optimization parameters of the module integrated circuit, and performing stress distribution optimization of the stretchable flexible circuit board based on the stress optimization parameters. The present invention can improve the stretchability and reliability of the flexible circuit board.

Description

Technical Field

[0001] The invention relates to a stretchable flexible circuit board and a stress distribution optimization method thereof, and belongs to the field of material science. Background Art

[0002] Stretchable Flexible Circuit Boards (SFCBs or SFCS) are circuit boards that can be stretched under external forces without damaging their electrical functions. This type of circuit board combines the characteristics of flexibility and stretchability, enabling it to adapt to various shapes and sizes while maintaining circuit integrity.

[0003] Traditional methods for optimizing stress distribution in stretchable flexible circuit boards usually rely on simple geometric deformation designs, such as straight or serpentine conductive paths, and increasing the thickness of flexible materials or using elastomeric substrates to absorb stress. This approach lacks comprehensive consideration of island bridge structures, corrugated structures, microcrack designs, and microstructure designs, resulting in uneven stress distribution under complex deformation modes, and is unable to achieve high stretchability and long-term reliability. Summary of the invention

[0004] The present invention provides a stretchable flexible circuit board and a stress distribution optimization method thereof, the main purpose of which is to improve the stretchability and reliability of the flexible circuit board.

[0005] To achieve the above-mentioned purpose, the present invention provides a stretchable flexible circuit board and a stress distribution optimization method thereof, comprising:

[0006] Determine the application scenario of the circuit board and its deformation mode, analyze the stress characteristics of the deformation mode based on the application scenario, and define the circuit board requirements of the circuit board through the stress characteristics, wherein the circuit board requirements include circuit board size, circuit board shape, and circuit board electronic components;

[0007] According to the circuit board requirements, define the island bridge structure of the circuit board, wherein the island bridge structure includes a circuit board island and a circuit board bridge, calculate the component integration coefficient of the circuit board island, and when the component integration coefficient meets the preset component integration threshold, define the corrugated structure of the circuit board bridge;

[0008] Analyze the bridge characteristics and corrugated structure characteristics of the circuit board bridge and the corrugated structure, and construct the micro-crack structure of the circuit board bridge and the corrugated structure based on the bridge characteristics and the corrugated structure characteristics;

[0009] Establishing the surface microstructure of the circuit board island and the circuit board bridge, calculating the stress coordination coefficient of the surface microstructure to the corrugated structure and the microcrack structure, and when the stress coordination coefficient meets the preset stress coordination threshold, constructing the integrated circuit of the circuit board based on the island bridge structure, the corrugated structure, the microcrack structure and the surface microstructure, and establishing a stretchable flexible circuit board of the circuit board based on the integrated circuit;

[0010] The integrated circuit is modularized to obtain a module integrated circuit, stress distribution data of the module integrated circuit is collected, stress optimization parameters of the module integrated circuit are analyzed based on the stress distribution data, and stress distribution optimization of the stretchable flexible circuit board is performed based on the stress optimization parameters.

[0011] Optionally, analyzing the stress characteristics of the deformation mode based on the application scenario includes:

[0012] Analyzing the scenario characteristics of the application scenario;

[0013] Analyzing the deformation frequency and deformation amplitude of the deformation mode according to the scene characteristics;

[0014] Based on the deformation frequency and deformation amplitude, obtaining stress simulation data of the deformation mode;

[0015] Analyzing the mode stress state of the deformation mode through the stress simulation data, wherein the mode stress state includes maximum stress, minimum stress, stress gradient and stress concentration factor;

[0016] The stress characteristics of the deformation mode are determined by combining the maximum stress, minimum stress, stress gradient and stress concentration factor.

[0017] Optionally, defining the island bridge structure of the circuit board according to the circuit board requirements includes:

[0018] Establishing a component layout of electronic components of the circuit board corresponding to the circuit board requirements;

[0019] Determine the island coordinates, island shape, island material and island size of the circuit board according to the component layout and the circuit board requirements;

[0020] constructing a circuit board island of the circuit board based on the island coordinates, island shape, island material and island size;

[0021] Determining a connection path of the circuit board island according to the corresponding stress characteristics of the circuit board;

[0022] calculating the circuit continuity of the connection path;

[0023] When the circuit continuity meets a preset circuit continuity threshold, defining a circuit board bridge of the circuit board based on the connection path;

[0024] The circuit board island and the circuit board bridge are combined to determine the island-bridge structure of the circuit board.

[0025] Optionally, the calculating the circuit continuity of the connection path includes:

[0026] defining a maximum allowable resistance of the connection path and a connection path length;

[0027] determining a connection path strain and a connection path temperature of the connection path;

[0028] identifying a deformed connection path length of the connection path under the connection path strain;

[0029] Based on the maximum allowable resistance, the connection path length, the connection path strain, the connection path temperature, and the deformed connection path length, the circuit continuity of the connection path is calculated using the following formula:

[0030]

[0031] in, Indicates the circuit continuity of the connection path, Indicates the maximum permissible resistance of the connection path, represents the wire resistance under connection path strain, connection path temperature and deformed connection path length, represents the connection point resistance under connection path strain, connection path temperature and deformed connection path length, represents the connection path strain, Indicates the length of the connection path, represents the connection path strain, Indicates the connection path temperature.

[0032] Optionally, the calculating the component integration coefficient of the circuit board island includes:

[0033] determining a circuit board island area of ​​the circuit board island;

[0034] Analyze the island area, island component area and island wire area of ​​the circuit board island area;

[0035] Based on the island area, island component area and island wire area, the component integration coefficient of the circuit board island is calculated using the following formula:

[0036]

[0037] in, represents the component integration factor, represents the island element area, represents the area of ​​the island region, Represents the island conductor area.

[0038] Optionally, when the component integration system meets a preset component integration threshold, defining the corrugated structure of the circuit board bridge includes:

[0039] When the component integration system meets a preset component integration threshold, defining the corrugated structure requirements of the circuit board bridge;

[0040] Determining the corrugated structure type of the circuit board bridge according to the corrugated structure requirements;

[0041] Determining corrugation parameters of the corrugation structure type, wherein the corrugation parameters include wavelength, amplitude, peak-to-trough distance, and waveform angle;

[0042] Based on the corrugation parameters, defining the initial corrugation structure of the circuit board bridge;

[0043] calculating the electromagnetic compatibility of the corrugated initial structure with respect to the circuit board bridge;

[0044] When the electromagnetic compatibility meets a preset electromagnetic compatibility threshold, the initial corrugated structure is used as the corrugated structure of the circuit board bridge.

[0045] Optionally, constructing the circuit board bridge and the micro-crack structure of the corrugated structure based on the bridge feature and the corrugated structure feature includes:

[0046] Determining micro-crack points of the circuit board bridge and the corrugated structure according to the bridge characteristics and the corrugated structure characteristics;

[0047] defining an initial microcrack state of the microcrack point;

[0048] Establishing a bridge fracture model of the circuit board bridge, the corrugated structure and the initial microcrack state;

[0049] defining a given load for the bridge fracture model;

[0050] Calculating the stress intensity factor of the bridge fracture model under the given load;

[0051] Analyzing crack propagation of the initial microcrack state according to the stress intensity factor;

[0052] Optimizing the initial microcrack state based on the crack extension to obtain a target microcrack state;

[0053] The target microcrack state is used to construct the microcrack structure of the circuit board bridge and the corrugated structure.

[0054] Optionally, the calculating the stress intensity factor of the bridge fracture model under the given load includes:

[0055] Determine the crack length and far-field stress at the crack tip corresponding to the bridge fracture model under the given load;

[0056] defining a zone width of the crack tip under the given load;

[0057] A stress intensity factor at the crack tip is calculated based on the crack length, the far-field stress, and the zone width.

[0058] Optionally, the calculating the stress intensity factor at the crack tip based on the crack length, the far-field stress and the zone width includes:

[0059] The stress intensity factor at the crack tip is calculated using the following formula:

[0060]

[0061] in, represents the stress intensity factor at the crack tip, represents pi, Indicates the width of the region, represents the crack length, represents the far-field stress.

[0062] Optionally, modularizing the integrated circuit to obtain a modular integrated circuit includes:

[0063] Analyzing circuit indicators of the integrated circuit;

[0064] Determining a functional module of the integrated circuit according to the circuit indicator;

[0065] Defining the communication protocol and connection routing of the functional modules;

[0066] Based on the communication protocol and the connection routing, the integrated circuit is modularized to obtain a modular integrated circuit.

[0067] Compared with the problems described in the background technology, first of all, the circuit board has excellent flexibility and stretchability, can adapt to various complex deformation modes, meet the needs of different application scenarios, and can maintain stable electrical performance in wearable devices, medical monitoring or flexible display technology. Secondly, by analyzing the stress characteristics of the circuit board and defining specific circuit board requirements, we ensure that the size, shape and layout of the circuit board and electronic components maximize functionality and reliability. The introduction of the island bridge structure and the corrugated structure not only improves the mechanical strength of the circuit board, but also enhances its stress dispersion ability during the stretching process. The construction of the microcrack structure further improves the fatigue life of the circuit board under repeated deformation. In addition, the establishment of the surface microstructure and the calculation of the stress coordination coefficient ensure that the circuit board can effectively reduce stress concentration and prevent early failure when subjected to external loads. The modular integrated circuit design makes the production and maintenance of the circuit board more convenient. At the same time, by collecting stress distribution data and analyzing stress optimization parameters, we can optimize the circuit board in a targeted manner to further improve its performance and reliability. Therefore, the present invention can improve the stretchability and reliability of the flexible circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic diagram of a process of a stretchable flexible circuit board and a method for optimizing stress distribution thereof provided in one embodiment of the present invention;

[0069] Figure 2 A schematic diagram of a module for implementing the stretchable flexible circuit board and the stress distribution optimization method thereof provided in one embodiment of the present invention.

[0070] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0071] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0072] The embodiment of the present application provides a stretchable flexible circuit board and a method for optimizing its stress distribution. The execution subject of the stretchable flexible circuit board and the method for optimizing its stress distribution includes but is not limited to at least one of the electronic devices such as a server and a terminal that can be configured to execute the method provided by the embodiment of the present application. In other words, the stretchable flexible circuit board and the method for optimizing its stress distribution can be executed by software or hardware installed in a terminal device or a server device. The server includes but is not limited to: a single server, a server cluster, a cloud server or a cloud server cluster, etc.

[0073] Embodiment 1:

[0074] Reference Figure 1FIG. 1 is a flow chart of a stretchable flexible circuit board and a method for optimizing stress distribution thereof provided by an embodiment of the present invention. In this embodiment, the stretchable flexible circuit board and the method for optimizing stress distribution thereof include:

[0075] S1. Determine the application scenario of the circuit board and its deformation mode, analyze the stress characteristics of the deformation mode based on the application scenario, and define the circuit board requirements of the circuit board through the stress characteristics, wherein the circuit board requirements include circuit board size, circuit board shape, and circuit board electronic components.

[0076] It should be explained that the application scenarios of the circuit board refer to the specific environment or purpose in which the stretchable flexible circuit board (SFCB) will be used or integrated. These scenarios usually involve situations where the circuit board needs to adapt to shape changes, mechanical deformation or dynamic movement, such as wearable devices, medical implants, flexible displays, etc. The deformation mode refers to the specific type of mechanical deformation that the circuit board may experience in these application scenarios, including stretching, compression, bending, twisting and shearing.

[0077] Based on the application scenario, the present invention analyzes the stress characteristics of the deformation mode to ensure that the stress characteristics of the stretchable flexible circuit board in the application scenario can be taken into account during the design stage, thereby improving its performance and reliability in actual use.

[0078] In detail, analyzing the stress characteristics of the deformation mode based on the application scenario includes:

[0079] Analyzing the scenario characteristics of the application scenario;

[0080] Analyzing the deformation frequency and deformation amplitude of the deformation mode according to the scene characteristics;

[0081] Based on the deformation frequency and deformation amplitude, obtaining stress simulation data of the deformation mode;

[0082] Analyzing the mode stress state of the deformation mode through the stress simulation data, wherein the mode stress state includes maximum stress, minimum stress, stress gradient and stress concentration factor;

[0083] The stress characteristics of the deformation mode are determined by combining the maximum stress, minimum stress, stress gradient and stress concentration factor.

[0084] Among them, the scenario characteristics refer to the specific environment and conditions of the application scenario, the deformation frequency refers to the number of times the circuit board undergoes a specific deformation mode within a certain period of time, the deformation amplitude refers to the maximum deformation that the circuit board can achieve under the specific deformation mode, the stress simulation data is the stress distribution information of the circuit board under the specific deformation mode obtained by computational mechanics methods (such as finite element analysis), the maximum stress refers to the highest stress value reached inside the circuit board material under the specific deformation mode, the minimum stress refers to the lowest stress value inside the circuit board material under the specific deformation mode, the stress gradient refers to the distribution change rate of stress inside the circuit board material, the stress concentration coefficient refers to the ratio of local stress caused by sudden changes in geometric shape (such as holes, notches, etc.) to nominal stress, and the stress characteristic refers to the comprehensive information obtained by analyzing the stress simulation data, describing the stress state of the circuit board under the specific deformation mode.

[0085] Optionally, the stress simulation data of the deformation mode obtained based on the deformation frequency and deformation amplitude may be collected by simulation software.

[0086] The present invention defines the circuit board requirements of the circuit board through the stress characteristics, and can design a stretchable flexible circuit board that meets both electrical performance and can work stably in specific application scenarios. Among them, the circuit board size refers to the external physical size of the circuit board, including length, width and thickness, the circuit board shape refers to the geometric outline and structure of the circuit board, which can be a regular rectangle, circle, or irregular shape, and the circuit board electronic components refer to various electronic components installed on the circuit board, including but not limited to active components, passive components, sensors, interconnection components and functional modules.

[0087] S2. According to the circuit board requirements, define the island bridge structure of the circuit board, wherein the island bridge structure includes a circuit board island and a circuit board bridge, calculate the component integration coefficient of the circuit board island, and when the component integration coefficient meets a preset component integration threshold, define the corrugated structure of the circuit board bridge.

[0088] According to the requirements of the circuit board, the present invention defines the island bridge structure of the circuit board and can define an island bridge structure that can adapt to the expected deformation and maintain the integrity of the electrical connection, thereby realizing the design of a stretchable flexible circuit board.

[0089] In detail, the island bridge structure of the circuit board is defined according to the circuit board requirements, including:

[0090] Establishing a component layout of electronic components of the circuit board corresponding to the circuit board requirements;

[0091] Determine the island coordinates, island shape, island material and island size of the circuit board according to the component layout and the circuit board requirements;

[0092] constructing a circuit board island of the circuit board based on the island coordinates, island shape, island material and island size;

[0093] Determining a connection path of the circuit board island according to the corresponding stress characteristics of the circuit board;

[0094] calculating the circuit continuity of the connection path;

[0095] When the circuit continuity meets a preset circuit continuity threshold, defining a circuit board bridge of the circuit board based on the connection path;

[0096] The circuit board island and the circuit board bridge are combined to determine the island-bridge structure of the circuit board.

[0097] Among them, the component layout refers to the position and arrangement of electronic components on the circuit board, the island coordinates refer to the precise position of each rigid island (the part containing electronic components) on the circuit board, the island shape refers to the appearance of the rigid island, usually a rectangle, circle or other geometric shape, the island material refers to the physical material that constitutes the rigid island, the island size refers to the physical size of the rigid island, including length, width and height, the circuit board island refers to the rigid area on the circuit board used to fix electronic components, the connection path refers to the planned route of the flexible bridge between islands on the circuit board, the circuit continuity refers to the continuity and integrity of the conductive path on the circuit board under physical deformation, the circuit continuity threshold refers to the minimum standard that the circuit continuity must meet to ensure that the circuit function is not affected, the circuit board bridge refers to the flexible conductive part connecting the islands on the circuit board, and the island bridge structure refers to the design that combines the rigid island with the flexible bridge.

[0098] Further, the calculating the circuit continuity of the connection path includes:

[0099] defining a maximum allowable resistance of the connection path and a connection path length;

[0100] determining a connection path strain and a connection path temperature of the connection path;

[0101] identifying a deformed connection path length of the connection path under the connection path strain;

[0102] Based on the maximum allowable resistance, the connection path length, the connection path strain, the connection path temperature, and the deformed connection path length, the circuit continuity of the connection path is calculated using the following formula:

[0103]

[0104] in, Indicates the circuit continuity of the connection path, Indicates the maximum permissible resistance of the connection path, represents the wire resistance under connection path strain, connection path temperature and deformed connection path length, represents the connection point resistance under connection path strain, connection path temperature and deformed connection path length, represents the connection path strain, Indicates the length of the connection path, represents the connection path strain, Indicates the connection path temperature.

[0105] Among them, the maximum allowable resistance refers to the maximum resistance value that the connection path can withstand when the circuit continuity is not considered to be interrupted, the connection path length refers to the original conductive path length between two electronic components on the circuit board, the connection path strain refers to the relative length change of the connection path when subjected to external force, the connection path temperature refers to the temperature of the connection path during operation, the deformed connection path length refers to the actual length of the connection path after being strained, and the circuit continuity refers to the ability of the connection path to maintain electrical connection under conditions of deformation and temperature changes.

[0106] The present invention is used to evaluate the parameters of component integration density and efficiency of a specific area (island) on a circuit board by calculating the component integration coefficient of the circuit board island. This coefficient can help designers optimize the distribution of components during the circuit board layout stage and improve the performance and reliability of the circuit board.

[0107] In detail, the calculating of the component integration coefficient of the circuit board island includes:

[0108] determining a circuit board island area of ​​the circuit board island;

[0109] Analyze the island area, island component area and island wire area of ​​the circuit board island area;

[0110] Based on the island area, island component area and island wire area, the component integration coefficient of the circuit board island is calculated using the following formula:

[0111]

[0112] in, represents the component integration factor, represents the island element area, represents the area of ​​the island region, Represents the island conductor area.

[0113] Among them, the circuit board island area refers to a relatively rigid part on the circuit board, the island area area refers to the total area of ​​the circuit board island area, the island component area refers to the total area occupied by all electronic components in the island area, the island wire area refers to the total area occupied by all wires (including traces and connecting wires) in the island area, and the component integration coefficient refers to a parameter used to evaluate the efficiency and density of component integration in the island area of ​​the circuit board.

[0114] In the present invention, when the component integration system meets the preset component integration threshold, defining the corrugated structure of the circuit board bridge can define a circuit board bridge corrugated structure that meets the preset component integration threshold and ensure that it meets the performance and functional requirements of the circuit board.

[0115] In detail, when the component integration system meets a preset component integration threshold, the corrugated structure of the circuit board bridge is defined, including:

[0116] When the component integration system meets a preset component integration threshold, defining the corrugated structure requirements of the circuit board bridge;

[0117] Determining the corrugated structure type of the circuit board bridge according to the corrugated structure requirements;

[0118] Determining corrugation parameters of the corrugation structure type, wherein the corrugation parameters include wavelength, amplitude, peak-to-trough distance, and waveform angle;

[0119] Based on the corrugation parameters, defining the initial corrugation structure of the circuit board bridge;

[0120] calculating the electromagnetic compatibility of the corrugated initial structure with respect to the circuit board bridge;

[0121] When the electromagnetic compatibility meets a preset electromagnetic compatibility threshold, the initial corrugated structure is used as the corrugated structure of the circuit board bridge.

[0122] Among them, the component integration threshold is a preset standard or limit used to measure the degree of component integration on the circuit board. The corrugated structure requirement refers to the requirement defined according to the overall design objectives and functional requirements of the circuit board, including the specific functions that the corrugated structure needs to achieve (such as enhancing mechanical strength, heat dissipation, shock absorption, electromagnetic shielding, etc.). The corrugated structure type refers to the specific shape and form of the corrugation, such as sine wave, square wave, sawtooth wave, etc. The wavelength refers to the length of a complete waveform (from one crest to the next crest) in the corrugated structure. The amplitude refers to the vertical distance between the crest and the trough in the corrugated structure, that is, the maximum height of the corrugation. The crest-trough distance refers to the horizontal distance from a crest to an adjacent trough in the corrugated structure. The waveform angle refers to the inclination angle of the corrugation. The initial corrugated structure refers to the corrugated structure preliminarily designed based on the corrugation parameters. The electromagnetic compatibility refers to the ability of the circuit board to work normally in an electromagnetic environment. The electromagnetic compatibility threshold refers to a preset standard used to measure the performance of the circuit board in terms of electromagnetic compatibility. The corrugated structure refers to the corrugated design that is finally determined and used for the circuit board bridge.

[0123] Optionally, the calculating of the electromagnetic compatibility of the initial corrugated structure with respect to the circuit board bridge may be evaluated by measuring S-parameters of the corrugated structure through scattering parameter (S-parameter) analysis.

[0124] S3. Analyze the bridge characteristics and corrugated structure characteristics of the circuit board bridge and the corrugated structure, and construct the microcrack structure of the circuit board bridge and the corrugated structure based on the bridge characteristics and corrugated structure characteristics.

[0125] It should be explained that the bridge feature refers to the conductive path on the circuit board used to connect different circuit areas (islands), and the corrugated structure feature refers to the structural feature with a corrugated shape designed on the bridge of the circuit board.

[0126] Based on the bridge characteristics and corrugated structure characteristics, the present invention constructs the circuit board bridge and the microcrack structure of the corrugated structure to construct a microcrack model of the circuit board bridge and predict its behavior under specific conditions, providing a basis for the design and reliability evaluation of the circuit board.

[0127] In detail, the construction of the circuit board bridge and the micro-crack structure of the corrugated structure based on the bridge characteristics and the corrugated structure characteristics includes:

[0128] Determining micro-crack points of the circuit board bridge and the corrugated structure according to the bridge characteristics and the corrugated structure characteristics;

[0129] defining an initial microcrack state of the microcrack point;

[0130] Establishing a bridge fracture model of the circuit board bridge, the corrugated structure and the initial microcrack state;

[0131] defining a given load for the bridge fracture model;

[0132] Calculating the stress intensity factor of the bridge fracture model under the given load;

[0133] Analyzing crack propagation of the initial microcrack state according to the stress intensity factor;

[0134] Optimizing the initial microcrack state based on the crack extension to obtain a target microcrack state;

[0135] The target microcrack state is used to construct the microcrack structure of the circuit board bridge and the corrugated structure.

[0136] Among them, the microcrack point refers to the specific location of the tiny crack that exists or may be formed in the circuit board bridge and corrugated structure, the initial microcrack state refers to the state of the microcrack before the analysis or simulation begins, including the size (length, width, depth), shape and position of the crack, the bridge fracture model is a numerical model used to simulate and analyze the fracture behavior of the circuit board bridge when subjected to load, the given load refers to the external force or constraint applied to the circuit board bridge during the simulation process, these loads can be static or dynamic, including mechanical loads, thermal loads or a combination of the two, the stress intensity factor refers to a parameter that quantifies the stress state at the crack tip, which determines whether the crack extends and the speed of the extension, the crack extension refers to the process of the microcrack growing from the initial state under the action of load, the target microcrack state refers to the final state of the microcrack obtained by simulation and analysis under the action of a given load, and the microcrack structure refers to a crack network composed of one or more microcrack points in the circuit board bridge and corrugated structure.

[0137] Furthermore, the calculating of the stress intensity factor of the bridge fracture model under the given load includes:

[0138] Determine the crack length and far-field stress at the crack tip corresponding to the bridge fracture model under the given load;

[0139] defining a zone width of the crack tip under the given load;

[0140] Based on the crack length, the far-field stress and the zone width, the stress intensity factor at the crack tip is calculated using the following formula:

[0141]

[0142] in, represents the stress intensity factor at the crack tip, represents pi, Indicates the width of the region, represents the crack length, represents the far-field stress.

[0143] Among them, the crack length refers to the distance from the crack tip to the crack starting point, the far-field stress refers to the stress far away from the crack tip, the area width refers to the width of a specific area defined near the crack tip, and the crack tip refers to the end of the crack, that is, where the crack begins to expand.

[0144] S4. Establish the surface microstructure of the circuit board islands and bridges, calculate the stress coordination coefficient of the surface microstructure to the corrugated structure and the microcrack structure, and when the stress coordination coefficient meets the preset stress coordination threshold, construct the integrated circuit of the circuit board based on the island bridge structure, the corrugated structure, the microcrack structure and the surface microstructure, and establish a stretchable flexible circuit board of the circuit board based on the integrated circuit.

[0145] The present invention establishes the surface microstructure of the circuit board islands and circuit board bridges, which can establish the surface microstructure of the circuit board islands and circuit board bridges, and these structures are crucial to the electrical performance, thermal management and long-term reliability of the circuit board. The surface microstructure refers to the geometric morphology and characteristics of the surface of a material or object on a microscopic scale. In detail, the surface microstructure can be achieved by plasma cleaning technology.

[0146] The present invention calculates the stress coordination coefficient of the surface microstructure on the corrugated structure and the microcrack structure, and can calculate the influence of the surface microstructure on the stress state of the corrugated structure and the microcrack structure, thereby providing important information for the design and reliability analysis of the circuit board. Among them, the stress coordination coefficient refers to an index used to quantify the compatibility or consistency of stress distribution between different structures or material parts. In detail, the stress coordination coefficient can be analyzed by calculating the microstress and macrostress of the surface microstructure through a numerical model.

[0147] Optionally, when the stress coordination coefficient meets the preset stress coordination threshold, the integrated circuit of the circuit board can construct a circuit board integrated circuit based on the island bridge structure, the corrugated structure, the microcrack structure and the surface microstructure, while ensuring that it meets the preset stress coordination threshold, thereby improving the performance and reliability of the circuit board. The stress coordination threshold is a predetermined numerical standard used to evaluate the uniformity and compatibility of stress distribution in the circuit board structure, and the circuit board integrated circuit refers to an electronic circuit integrated on a printed circuit board (PCB).

[0148] S5. Modularize the integrated circuit to obtain a module integrated circuit, collect stress distribution data of the module integrated circuit, analyze stress optimization parameters of the module integrated circuit based on the stress distribution data, and perform stress distribution optimization of the stretchable flexible circuit board based on the stress optimization parameters.

[0149] The present invention modularizes the integrated circuit to obtain a modular integrated circuit, which can complete the modular design of the integrated circuit and obtain a modular integrated circuit, thereby helping to improve the maintainability, scalability and reusability of the circuit.

[0150] In detail, modularizing the integrated circuit to obtain a modular integrated circuit includes:

[0151] Analyzing circuit indicators of the integrated circuit;

[0152] Determining a functional module of the integrated circuit according to the circuit indicator;

[0153] Defining the communication protocol and connection routing of the functional modules;

[0154] Based on the communication protocol and the connection routing, the integrated circuit is modularized to obtain a modular integrated circuit.

[0155] Among them, the circuit indicators refer to a series of parameters used to measure the performance of integrated circuits, the functional modules refer to the independent parts of integrated circuits that implement specific functions, the communication protocol refers to a set of rules and standards followed when exchanging data between modules, which defines the data format, signal level, transmission rate, error detection and correction methods, etc. The connecting traces refer to the electrical paths on the integrated circuit or printed circuit board (PCB) used to connect different functional modules, and the module integrated circuit refers to an integrated circuit that divides the entire integrated circuit into multiple modules according to function, each module can independently implement specific functions, and interact with other modules through standard communication protocols and connecting traces.

[0156] The present invention collects stress distribution data of the module integrated circuit, and analyzes the stress optimization parameters of the module integrated circuit based on the stress distribution data. The stress optimization parameters of the module integrated circuit can be analyzed based on the stress distribution data, and optimized to improve the reliability and performance of the circuit. Wherein, the stress distribution data refers to a series of data obtained by experimental measurement or numerical simulation, and the stress optimization parameters refer to a series of parameters that need to be adjusted through the design optimization process in order to improve the mechanical properties and reliability of the circuit board, such as geometric parameters, material parameters, layout parameters, connection parameters, boundary conditions, load conditions and other parameters. In detail, the stress optimization parameters can be determined by optimizing the target, such as reducing the maximum stress, homogenizing the stress distribution, reducing stress concentration, etc.

[0157] Compared with the problems described in the background technology, first of all, the circuit board has excellent flexibility and stretchability, can adapt to various complex deformation modes, meet the needs of different application scenarios, and can maintain stable electrical performance in wearable devices, medical monitoring or flexible display technology. Secondly, by analyzing the stress characteristics of the circuit board and defining specific circuit board requirements, we ensure that the size, shape and layout of the circuit board and electronic components maximize functionality and reliability. The introduction of the island bridge structure and the corrugated structure not only improves the mechanical strength of the circuit board, but also enhances its stress dispersion ability during the stretching process. The construction of the microcrack structure further improves the fatigue life of the circuit board under repeated deformation. In addition, the establishment of the surface microstructure and the calculation of the stress coordination coefficient ensure that the circuit board can effectively reduce stress concentration and prevent early failure when subjected to external loads. The modular integrated circuit design makes the production and maintenance of the circuit board more convenient. At the same time, by collecting stress distribution data and analyzing stress optimization parameters, we can optimize the circuit board in a targeted manner to further improve its performance and reliability. Therefore, the present invention can improve the stretchability and reliability of the flexible circuit board.

[0158] Embodiment 2:

[0159] like Figure 2 Shown is a functional module diagram of a stretchable flexible circuit board and its stress distribution optimization system of the present invention.

[0160] The stretchable flexible circuit board and its stress distribution optimization system 200 described in the present invention can be installed in an electronic device. According to the functions to be implemented, the stretchable flexible circuit board and its stress distribution optimization system can include a circuit board demand analysis module 201, a corrugated structure determination module 202, a microcrack structure determination module 203, an integrated circuit construction module 204 and a stress distribution optimization module 205. The module described in the present invention can also be called a unit, which refers to a series of computer program segments that can be executed by an electronic device processor and can complete fixed functions, which are stored in the memory of the electronic device.

[0161] In the embodiment of the present invention, the functions of each module / unit are as follows:

[0162] The circuit board requirement analysis module 201 is used to determine the application scenario of the circuit board and its deformation mode, analyze the stress characteristics of the deformation mode based on the application scenario, and define the circuit board requirements of the circuit board through the stress characteristics, wherein the circuit board requirements include circuit board size, circuit board shape and circuit board electronic components;

[0163] The corrugation structure determination module 202 is used to define the island bridge structure of the circuit board according to the circuit board requirements, wherein the island bridge structure includes a circuit board island and a circuit board bridge, calculate the component integration coefficient of the circuit board island, and define the corrugation structure of the circuit board bridge when the component integration coefficient meets the preset component integration threshold;

[0164] The microcrack structure determination module 203 is used to analyze the bridge characteristics and corrugation structure characteristics of the circuit board bridge and the corrugation structure, and construct the microcrack structure of the circuit board bridge and the corrugation structure based on the bridge characteristics and corrugation structure characteristics;

[0165] The integrated circuit construction module 204 is used to establish the surface microstructure of the circuit board island and the circuit board bridge, calculate the stress coordination coefficient of the surface microstructure to the corrugated structure and the microcrack structure, and when the stress coordination coefficient meets the preset stress coordination threshold, construct the integrated circuit of the circuit board based on the island bridge structure, the corrugated structure, the microcrack structure and the surface microstructure, and establish a stretchable flexible circuit board of the circuit board based on the integrated circuit;

[0166] The stress distribution optimization module 205 is used to modularize the integrated circuit to obtain a module integrated circuit, collect stress distribution data of the module integrated circuit, analyze stress optimization parameters of the module integrated circuit based on the stress distribution data, and perform stress distribution optimization of the stretchable flexible circuit board based on the stress optimization parameters.

[0167] In detail, each module in the stretchable flexible circuit board and its stress distribution optimization system 200 in the embodiment of the present invention is used in the same manner as above. Figure 1 The stretchable flexible circuit board and its stress distribution optimization method described in the invention have the same technical means and can produce the same technical effects, so they will not be repeated here.

[0168] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for optimizing stress distribution of a stretchable flexible circuit board, characterized in that: The method comprises: Determine an application scenario of the circuit board and its deformation mode, analyze stress characteristics of the deformation mode based on the application scenario, and define circuit board requirements of the circuit board through the stress characteristics, wherein the circuit board requirements include circuit board size, circuit board shape, and circuit board electronic components; According to the circuit board requirements, define the island bridge structure of the circuit board, wherein the island bridge structure includes a circuit board island and a circuit board bridge, calculate the component integration coefficient of the circuit board island, and when the component integration coefficient meets a preset component integration threshold, define the corrugated structure of the circuit board bridge; Analyze the bridge characteristics and corrugated structure characteristics of the circuit board bridge and the corrugated structure, and construct the micro-crack structure of the circuit board bridge and the corrugated structure based on the bridge characteristics and the corrugated structure characteristics; Establishing the surface microstructure of the circuit board island and the circuit board bridge, calculating the stress coordination coefficient of the surface microstructure to the corrugated structure and the microcrack structure, and when the stress coordination coefficient meets the preset stress coordination threshold, constructing the integrated circuit of the circuit board based on the island bridge structure, the corrugated structure, the microcrack structure and the surface microstructure, and establishing a stretchable flexible circuit board of the circuit board based on the integrated circuit; The integrated circuit is modularized to obtain a module integrated circuit, stress distribution data of the module integrated circuit is collected, stress optimization parameters of the module integrated circuit are analyzed based on the stress distribution data, and stress distribution optimization of the stretchable flexible circuit board is performed based on the stress optimization parameters.

2. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 1, characterized in that: The analyzing the stress characteristics of the deformation mode based on the application scenario includes: Analyzing the scenario characteristics of the application scenario; Analyzing the deformation frequency and deformation amplitude of the deformation mode according to the scene characteristics; Based on the deformation frequency and deformation amplitude, obtaining stress simulation data of the deformation mode; Analyzing the mode stress state of the deformation mode through the stress simulation data, wherein the mode stress state includes maximum stress, minimum stress, stress gradient and stress concentration factor; The stress characteristics of the deformation mode are determined by combining the maximum stress, minimum stress, stress gradient and stress concentration factor.

3. The stress distribution optimization method of a stretchable flexible circuit board according to claim 1, characterized in that: Defining the island bridge structure of the circuit board according to the circuit board requirements includes: Establishing a component layout of electronic components of the circuit board corresponding to the circuit board requirements; Determine the island coordinates, island shape, island material and island size of the circuit board according to the component layout and the circuit board requirements; constructing a circuit board island of the circuit board based on the island coordinates, island shape, island material and island size; Determining a connection path of the circuit board island according to the corresponding stress characteristics of the circuit board; calculating the circuit continuity of the connection path; When the circuit continuity meets a preset circuit continuity threshold, defining a circuit board bridge of the circuit board based on the connection path; The circuit board island and the circuit board bridge are combined to determine the island-bridge structure of the circuit board.

4. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 3, characterized in that: The calculating the circuit continuity of the connection path comprises: defining a maximum allowable resistance of the connection path and a connection path length; determining a connection path strain and a connection path temperature of the connection path; identifying a deformed connection path length of the connection path under the connection path strain; Based on the maximum allowable resistance, the connection path length, the connection path strain, the connection path temperature, and the deformed connection path length, the circuit continuity of the connection path is calculated using the following formula: in, Indicates the circuit continuity of the connection path, Indicates the maximum permissible resistance of the connection path, represents the wire resistance under connection path strain, connection path temperature and deformed connection path length, represents the connection point resistance under connection path strain, connection path temperature and deformed connection path length, represents the deformation connection path length, Indicates the length of the connection path, represents the connection path strain, Indicates the connection path temperature.

5. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 1, characterized in that: The calculating the component integration coefficient of the circuit board island includes: determining a circuit board island area of ​​the circuit board island; Analyze the island area, island component area and island wire area of ​​the circuit board island area; Based on the island area, island component area and island wire area, the component integration coefficient of the circuit board island is calculated using the following formula: in, represents the component integration factor, represents the island element area, represents the area of ​​the island region, Represents the island conductor area.

6. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 1, wherein: When the component integration coefficient meets a preset component integration threshold, defining the corrugated structure of the circuit board bridge includes: When the component integration coefficient meets a preset component integration threshold, defining the corrugated structure requirements of the circuit board bridge; Determining the corrugated structure type of the circuit board bridge according to the corrugated structure requirements; Determining corrugation parameters of the corrugation structure type, wherein the corrugation parameters include wavelength, amplitude, peak-to-trough distance, and waveform angle; Based on the corrugation parameters, defining the initial corrugation structure of the circuit board bridge; calculating the electromagnetic compatibility of the corrugated initial structure with respect to the circuit board bridge; When the electromagnetic compatibility meets a preset electromagnetic compatibility threshold, the initial corrugated structure is used as the corrugated structure of the circuit board bridge.

7. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 1, characterized in that: The method of constructing the circuit board bridge and the micro-crack structure of the corrugated structure based on the bridge characteristics and the corrugated structure characteristics includes: Determining micro-crack points of the circuit board bridge and the corrugated structure according to the bridge characteristics and the corrugated structure characteristics; defining an initial microcrack state of the microcrack point; Establishing a bridge fracture model of the circuit board bridge, the corrugated structure and the initial microcrack state; defining a given load for the bridge fracture model; Calculating the stress intensity factor of the bridge fracture model under the given load; Analyzing crack propagation of the initial microcrack state according to the stress intensity factor; Optimizing the initial microcrack state based on the crack extension to obtain a target microcrack state; The target microcrack state is used to construct the microcrack structure of the circuit board bridge and the corrugated structure.

8. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 7, characterized in that: The calculating the stress intensity factor of the bridge fracture model under the given load comprises: Determine the crack length and far-field stress at the crack tip corresponding to the bridge fracture model under the given load; defining a zone width of the crack tip under the given load; A stress intensity factor at the crack tip is calculated based on the crack length, the far-field stress, and the zone width.

9. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 8, characterized in that: The calculating the stress intensity factor at the crack tip based on the crack length, the far-field stress and the zone width comprises: The stress intensity factor at the crack tip is calculated using the following formula: in, represents the stress intensity factor at the crack tip, represents pi, Indicates the width of the region, represents the crack length, represents the far-field stress.

10. The method for optimizing stress distribution of a stretchable flexible circuit board according to claim 1, characterized in that: The integrated circuit is modularized to obtain a modular integrated circuit, comprising: Analyzing circuit indicators of the integrated circuit; Determining a functional module of the integrated circuit according to the circuit indicator; Defining the communication protocol and connection routing of the functional modules; Based on the communication protocol and the connection routing, the integrated circuit is modularized to obtain a modular integrated circuit.

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