Wet diffusion simulation device, moisture distribution simulation method and computer equipment

Abstract

The invention relates to the technical field of wet diffusion simulation, and discloses a wet diffusion simulation device, a moisture distribution simulation method and computer equipment, the wet diffusion simulation device comprises an engineering project module, a mechanical design platform, a geometric structure module, a solver and a plug-in module; the geometric structure module is used for receiving or generating an embedded component packaging structure, and the grid division module is used for performing grid division on the embedded component packaging structure; the plug-in module is used for reading moisture attributes from a material library and receiving moisture boundary conditions, and is used for converting the moisture attributes into a first command stream and converting the moisture boundary conditions into a second command stream; the solver is used for generating a first result file based on the moisture diffusion theoretical model, the first command stream and the second command stream, and the post-processing module is used for generating an image representing a moisture concentration distribution result based on the first result file.

Description

Technical Field

[0001] The invention relates to the technical field of wet diffusion simulation, and in particular to a wet diffusion simulation device, a moisture distribution simulation method and a computer device. Background Art

[0002] Embedded Component Packaging (ECP) is a packaging technology that embeds electronic components (such as resistors, capacitors, inductors or chips) directly into a printed circuit board (PCB) or other types of substrates. Compared with surface mount technology (SMT), ECP can achieve smaller package size, enhance reliability, improve production efficiency, and provide greater design flexibility for electronic components.

[0003] However, the polymer materials commonly used in ECP structures are prone to absorb moisture in the surrounding environment, which has a great impact on their own reliability. For example, moisture causes the expansion of different component materials, thereby generating wet stress. Moisture changes the properties of the material itself, thereby changing the heat transfer and stress distribution in the package or changing the electrical and optical properties of the package medium, affecting the working performance of the device. The impact of local moisture on the ECP structure is more obvious. For example, it weakens the adhesion between the interfaces of the packaging materials. During the high-temperature reflow process, vapor pressure is generated because the internal moisture cannot be quickly discharged. In the case of internal cracks, the vapor pressure may cause "popcorn" failure and device failure. It causes corrosion under the action of electric field and heat, such as electromigration, conductive anode wire, etc. In severe cases, it may cause short circuits and open circuits. Therefore, it is very important to accurately simulate and calculate the moisture concentration distribution at various locations of the ECP structure to evaluate the reliability of the ECP structure.

[0004] At present, the moisture concentration distribution in various parts of the ECP structure can be simulated based on finite element software. However, as a general software integrating multiple analyses, finite element software has the main analysis functions of structural analysis, thermal analysis or electromagnetic field analysis, and does not have moisture-related simulation functions. Directly using the finite element software solver to implement the moisture solution function may lead to low accuracy of the simulation results. Summary of the invention

[0005] In view of this, the present invention provides a wet diffusion simulation device, a moisture distribution simulation method and a computer device to improve the accuracy of the simulation results of moisture concentration distribution.

[0006] In a first aspect, the present invention provides a moisture diffusion simulation device, comprising an engineering project module, a mechanical design platform, a geometric structure module, a solver and a plug-in module, wherein the mechanical design platform comprises a meshing module and a post-processing module, the engineering project module is configured with a material library characterizing the moisture properties of a plurality of materials, the solver is configured with a moisture diffusion theoretical model, the moisture diffusion theoretical model is used to characterize the diffusion process of moisture in an embedded component packaging structure; the geometric structure module is used to receive or generate an embedded component packaging structure, and send the embedded component packaging structure to the meshing module, the meshing module is used to mesh the embedded component packaging structure, and send the meshed embedded component packaging structure to the solver; the plug-in module is used to read the moisture properties corresponding to the embedded component packaging structure from the material library and receive the moisture boundary conditions, is used to convert the moisture properties into a first command stream and convert the moisture boundary conditions into a second command stream, and is used to send the first command stream and the second command stream to the solver; the solver is used to generate a first result file based on the moisture diffusion theoretical model, the first command stream and the second command stream, and send the first result file to the post-processing module through the plug-in module, the post-processing module is used to generate an image characterizing the moisture concentration distribution result based on the first result file.

[0007] The moisture diffusion simulation device provided in this embodiment configures a material library that characterizes the moisture properties of various materials in the engineering project module 110 of the finite element work platform, configures a moisture diffusion theoretical model in the solver 140 of the finite element work platform, and adds a plug-in module 150 on the finite element work platform, which can make the solver of the finite element work platform more suitable for moisture diffusion simulation, thereby accurately simulating and calculating the moisture concentration at various locations of the embedded component packaging structure, improving the accuracy of the moisture concentration at key locations of the embedded component packaging structure (such as leads or chips, etc.), and improving the accuracy of the analyzed moisture diffusion path and speed, thereby being able to more accurately evaluate failure problems such as interface stratification, electrochemical corrosion or short circuit caused by moisture.

[0008] In an optional embodiment, the moisture diffusion theoretical model is a two-order diffusion theoretical model, which includes a physical diffusion model and a chemical adsorption model, and the first result file includes a physical diffusion result file and a chemical adsorption result file; the solver is used to generate a physical diffusion result file based on the physical diffusion model, the first command stream and the second command stream, and to generate a chemical adsorption result file based on the chemical adsorption model, the first command stream and the second command stream, and send the physical diffusion result file and the chemical adsorption result file to the plug-in module; the plug-in module generates an overlay result file based on the physical diffusion result file and the chemical adsorption result file, and sends the overlay result file to the post-processing module, and the post-processing module is used to generate an image representing the moisture concentration distribution result based on the overlay result file.

[0009] In this embodiment, the moisture diffusion theoretical model is represented by a double-order diffusion theoretical model, which can take into account the situation in which moisture chemically adsorbs and generates bound water during the diffusion process of polymer materials. This can make the simulation results of moisture diffusion closer to the actual situation, thereby more accurately guiding the packaging structure process design and packaging material selection, and reducing reliability problems caused by moisture.

[0010] In an optional embodiment, the double-order diffusion theory model is expressed by the following formula:

[0011]

[0012] Among them, M t represents the moisture content of the embedded component packaging structure at time t, M sat,1 represents the saturated mass of the embedded component packaging structure in the physical diffusion stage, D1 represents the diffusion coefficient in the physical diffusion stage, t represents time, h represents the thickness of the embedded component packaging structure, M sat,2 It represents the saturation mass of the embedded component packaging structure in the chemical adsorption stage, and D2 represents the diffusion coefficient in the chemical adsorption stage.

[0013] In an optional embodiment, the plug-in module generates a superposition result file based on the physical diffusion result file and the chemical adsorption result file by the following formula:

[0014]

[0015] Where C represents the moisture concentration of the embedded component packaging structure, C1 represents the moisture concentration of the embedded component packaging structure during the physical diffusion stage, and C sat1 represents the moisture saturation concentration of the embedded component packaging structure during the physical diffusion stage, C sat2 C2 represents the moisture saturation concentration of the embedded component packaging structure during the chemical adsorption stage, and C3 represents the moisture concentration of the embedded component packaging structure during the chemical adsorption stage.

[0016] In an alternative embodiment, the diffusion coefficient and / or the moisture saturation concentration is determined based on the temperature.

[0017] In an optional embodiment, the solver is also configured with a wet stress theoretical model, which is used to characterize the change process of wet stress of the embedded component packaging structure with moisture concentration; the solver is also used to generate a second result file based on the wet stress theoretical model and the first result file, and send the second result file to the post-processing module, and the post-processing module is also used to generate an image characterizing the wet stress distribution result based on the second result file.

[0018] In this embodiment, an image representing the wet stress distribution result is determined by a solver and a post-processing module, which can facilitate users to understand the wet stress at various positions of the embedded component packaging structure, analyze problems such as stress mismatch and interface delamination, and thus accurately guide the packaging structure design.

[0019] In an optional embodiment, the solver is also configured with a theoretical model of moisture-heat coupling stress, which is used to characterize the variation process of moisture-heat coupling stress of the embedded component packaging structure with moisture concentration and temperature; the solver is also used to generate a third result file based on the theoretical model of moisture-heat coupling stress and the first result file, and send the third result file to a post-processing module, and the post-processing module is also used to generate an image characterizing the moisture-heat coupling stress distribution result based on the third result file.

[0020] In an optional embodiment, the solver is also configured with a reflow vapor pressure stress theoretical model, which is used to characterize the change process of the moisture-heat coupling stress of the embedded component packaging structure with moisture concentration, temperature and vapor pressure; the solver is also used to generate a fourth result file based on the reflow vapor pressure stress theoretical model and the third result file, and send the fourth result file to the post-processing module, and the post-processing module is also used to generate an image characterizing the reflow vapor pressure stress distribution result based on the fourth result file.

[0021] In this embodiment, the image representing the reflow vapor pressure stress distribution result is determined by the solver and post-processing module, so as to simulate the reflow process, solve the maximum stress of the packaging structure before cracks appear, and predict the possible failure position of the packaging structure.

[0022] In a second aspect, the present invention provides a method for simulating moisture distribution, the method comprising: inputting an embedded component packaging structure into a wet diffusion simulation device, or generating an embedded component packaging structure based on the wet diffusion simulation device, wherein the wet diffusion simulation device is the wet diffusion simulation device of the first aspect or any corresponding embodiment thereof; inputting moisture boundary conditions and moisture properties corresponding to the embedded component packaging structure into the wet diffusion simulation device; and determining the moisture concentration distribution result of the embedded component packaging structure based on the output of the wet diffusion simulation device.

[0023] In a third aspect, the present invention provides a computer device, comprising the wet diffusion simulation device of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 is a structural block diagram of a wet diffusion simulation device according to an embodiment of the present invention;

[0026] Figure 2 is a structural block diagram of an embedded component packaging structure according to an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of moisture concentration distribution results based on a double-order diffusion theory model according to an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of moisture concentration distribution results based on Fick's diffusion theory model according to an embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of a result file superposition process according to an embodiment of the present invention;

[0030] Figure 6 is a schematic flow chart of a method for simulating moisture distribution according to an embodiment of the present invention;

[0031] Figure 7 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention.

[0032] Figure numerals: 110, engineering project module; 111, material library; 120, mechanical design platform; 121, meshing module; 122, post-processing module; 130, geometry module; 140, solver; 150, plug-in module; 201, printed circuit board; 202, solder layer; 203, solder mask layer; 204, copper layer; 205, adhesive layer; 206, insulating material layer; 207, semiconductor chip; 208, conductive material layer; 209, resistor layer; 210, inductor layer; 710, processor; 720, memory; 730, input device; 740, output device. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0034] Finite element software (such as ANSYS or ABAQUS) is a visual simulation platform developed for engineering problems. Its main analysis functions include structural analysis, nonlinear analysis, thermal analysis, electromagnetic field analysis, and fluid flow analysis. Finite element software does not support humidity-related parameters. Directly using the finite element software's solver to implement the moisture solution function may result in low accuracy of the simulation results.

[0035] The present invention provides a moisture diffusion simulation device, which is based on a finite element workbench (ANSYS Workbench) and provides a plug-in module and a material library for characterizing moisture properties of multiple materials, so as to more accurately simulate and calculate moisture concentrations at various locations of an ECP structure.

[0036] The wet diffusion simulation device provided by the present invention is described in detail below with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the wet diffusion simulation device provided by the present invention includes an engineering project (Project) module 110, a mechanical design platform (Mechanical) 120, a geometry (Geometry) module 130, a solver 140 and a plug-in module 150.

[0038] Among them, the mechanical design platform 120 includes a meshing module 121 and a post-processing module 122, the engineering project module 110 is configured with a material library 111 that characterizes the moisture properties (such as hygroscopicity and moisture permeability) of various materials, and the solver 140 is configured with a moisture diffusion theoretical model, which is used to characterize the diffusion process of moisture in the packaging structure of embedded components.

[0039] The geometry module 130 is used to receive or generate an embedded component packaging structure, and send the embedded component packaging structure to the meshing module 121. The meshing module 121 is used to mesh the embedded component packaging structure, and send the meshed embedded component packaging structure to the solver 140. Specifically, the geometry module 130 can obtain the embedded component packaging structure from a modeling tool such as SolidWorks, or can create and generate the embedded component packaging structure based on its own modeling tool DesignModeler or SpaceClaim in response to a user's operation.

[0040] In one example, if Figure 2 As shown, the embedded component packaging structure includes a printed circuit board (PCB) 201, a solder layer 202, a solder mask 203, a copper layer 204, an adhesive (ABF) layer 205, an insulating material (PI) layer 206, a semiconductor chip (DIE) 207, a conductive material (BT) layer 208, a resistor layer 209 and an inductor layer 210, and each layer is stacked. The semiconductor chip 207 can be a memory chip or a microprocessor chip, etc.

[0041] Specifically, the printed circuit board 201 is the base of the circuit board, which is composed of epoxy resin and glass fiber. The solder layer 202 is used to connect the components and the circuit board. The solder mask layer 203 covers the copper layer and is used to prevent incorrect soldering and short circuits. The copper layer 204 is the conductive copper trace on the circuit board and is used to connect the components on the circuit. The adhesive layer 205 is used to fix the copper layer 204. The insulating material layer 206 is used to protect the copper traces and components on the circuit board. The conductive material layer 208 is used to transmit specific signals or grounding. The resistor layer 209 is used to adjust the current or voltage. The inductor layer 210 is used to store and release electromagnetic energy.

[0042] The plug-in module 150 is used to read the moisture properties corresponding to the embedded component packaging structure from the material library 111 and receive the moisture boundary conditions corresponding to the embedded component packaging structure, to convert the moisture properties into a first command stream and to convert the moisture boundary conditions into a second command stream, and to send the first command stream and the second command stream to the solver 140. The first command stream and the second command stream may be command streams formed by ANSYS Parametric Design Language (APDL).

[0043] Specifically, the moisture boundary condition is used to reflect the interaction between the embedded component packaging structure and the external environment and the behavior characteristics of the embedded component packaging structure at the boundary. The moisture boundary condition can limit the solution range and possible solution space of the moisture diffusion theory model. For example, the moisture boundary condition can be the saturation concentration C of the material. sat wait.

[0044] In one example, the moisture boundary condition and the second command flow may be as shown in Table 1.

[0045] Table 1 Wet gas boundary conditions and second command flow

[0046]

[0047] The solver 140 is used to generate a first result file based on the moisture diffusion theoretical model, the first command stream and the second command stream, and send the first result file to the post-processing module 122 through the plug-in module 150. The post-processing module 122 is used to generate an image representing the moisture concentration distribution result based on the first result file. Exemplarily, the moisture diffusion theoretical model can be a Fick diffusion theoretical model or a double-order diffusion theoretical model, and the image generated by the post-processing module 122 can be as follows: Figure 3 or Figure 4 shown.

[0048] Specifically, the engineering project module 110, the mechanical design platform 120, the geometric structure module 130 and the solver 140 are built-in modules in the conventional finite element workbench (ANSYS Workbench), except that the engineering project module 110 is additionally configured with a material library 111 that characterizes the moisture properties of various materials, and the solver 140 is additionally configured with a moisture diffusion theoretical model.

[0049] The plug-in module 150 may refer to a functional extension module designed for the finite element work platform through the application customization tool (ANSYS Application Customization Toolkit, ACT). The plug-in module 150 integrates an application programming interface (Application Programming Interface, API) to realize the interaction between the plug-in module 150 and the engineering project module 110, the mechanical design platform 120 and the solver 140.

[0050] Specifically, the user inputs the embedded component packaging structure created in the modeling tool into the geometry module 130 through the graphical user interface (GUI) of the finite element platform. After receiving the embedded component packaging structure, the geometry module 130 transmits the embedded component packaging structure to the meshing module 121. The meshing module 121 meshes the embedded component packaging structure based on the user settings to generate a finite element mesh. Afterwards, in response to the user's operation, the plug-in module 150 reads the moisture properties corresponding to each material layer of the embedded component packaging structure from the material library, and receives the moisture boundary conditions corresponding to the embedded component packaging structure. Then, the plug-in module 150 converts the moisture properties corresponding to each material layer into a first command stream and the moisture boundary conditions into a second command stream and sends them to the solver 140. Finally, the solver 140 solves the moisture diffusion theoretical model based on the first command stream and the second command stream to obtain the solution result (i.e., the first result file), and sends the solution result to the post-processing module 122 for post-processing through the plug-in module 150 to generate an image representing the moisture concentration distribution result, so that the user can view the moisture concentration distribution of the embedded component packaging structure.

[0051] The moisture diffusion simulation device provided in this embodiment configures a material library that characterizes the moisture properties of various materials in the engineering project module 110 of the finite element work platform, configures a moisture diffusion theoretical model in the solver 140 of the finite element work platform, and adds a plug-in module 150 on the finite element work platform, which can make the solver of the finite element work platform more suitable for moisture diffusion simulation, thereby accurately simulating and calculating the moisture concentration at various locations of the embedded component packaging structure, improving the accuracy of the moisture concentration at key locations of the embedded component packaging structure (such as leads or chips, etc.), and improving the accuracy of the analyzed moisture diffusion path and speed, thereby being able to more accurately evaluate failure problems such as interface stratification, electrochemical corrosion or short circuit caused by moisture.

[0052] Exemplarily, the moisture diffusion theoretical model may be a Fick diffusion theoretical model or a double-order diffusion theoretical model.

[0053] Specifically, Fick's diffusion theory assumes that the diffusion coefficient of moisture is independent of moisture concentration, and that substances diffuse from high-concentration areas to low-concentration areas, and that the number of diffusion particles per unit cross section perpendicular to the diffusion direction (i.e., diffusion flux J) is proportional to the concentration gradient of the cross section. Without considering the interaction between moisture and other components, the Fick's diffusion theory model can be expressed by the following formula (1).

[0054]

[0055] Among them, M trepresents the moisture content of the embedded component packaging structure at time t, M sat represents the saturated mass of the embedded component packaging structure, n represents the order of expansion, D represents the diffusion coefficient, the diffusion coefficient can be the ratio of the diffusion flux J to the concentration gradient at the cross section, h represents the thickness of the embedded component packaging structure, and t represents time.

[0056] Specifically, for actual materials, the moisture concentration cannot be directly measured, but can be determined by the moisture absorption mass. The relationship between moisture concentration and moisture absorption mass can be shown as formula (2):

[0057]

[0058] Among them, C t It represents the moisture concentration of the embedded component packaging structure at time t, where the moisture concentration is the average concentration, and V represents the volume of the embedded component packaging structure.

[0059] The above formula (1) is relatively complex and inconvenient to use. The Fick diffusion theory model can be expressed by simplifying the formula (3).

[0060]

[0061] Specifically, the double-order diffusion theory believes that moisture will undergo chemical adsorption during the diffusion process of polymer materials to generate bound water. Therefore, there is no obvious saturation value in the moisture absorption process of the material. The moisture absorption mass of the material in the second half of the moisture absorption does not remain horizontal but increases slowly. In other words, the double-order diffusion theory believes that the moisture absorption of the material consists of two diffusion processes: physical diffusion (free water stage) and chemical adsorption diffusion (bound water stage). The two diffusion processes are independent of each other and can be expressed by the following formula (4) to represent the double-order diffusion theory model.

[0062]

[0063] Among them, M sat,1 represents the saturation mass of the embedded component packaging structure in the physical diffusion stage, D1 represents the diffusion coefficient in the physical diffusion stage, and M sat,2 represents the saturated mass of the embedded component packaging structure in chemical adsorption, D2 represents the diffusion coefficient in the chemical adsorption stage, the equation before the plus sign on the right side is the physical diffusion model, and the equation after the plus sign on the right side is the chemical adsorption model.

[0064] For ease of use, the double-order diffusion theory model can be expressed by simplifying formula (5).

[0065]

[0066] When the moisture diffusion theoretical model is a two-order diffusion theoretical model, since the physical diffusion process and the chemical adsorption process are independent of each other, the physical diffusion model and the chemical adsorption model can be solved separately by the solver 140, and finally the two solution results are superimposed by the plug-in module 150 to determine the solution result corresponding to the two-order diffusion theoretical model.

[0067] Specifically, in this embodiment, the first result file includes a physical diffusion result file and a chemical adsorption result file. The solver 140 is used to generate a physical diffusion result file based on a physical diffusion model, a first command stream, and a second command stream, and to generate a chemical adsorption result file based on a chemical adsorption model, a first command stream, and a second command stream, and to send the physical diffusion result file and the chemical adsorption result file to the plug-in module 150.

[0068] After receiving the physical diffusion result file and the chemical adsorption result file, the plug-in module 150 generates an overlay result file based on the physical diffusion result file and the chemical adsorption result file, and sends the overlay result file to the post-processing module 122, which is used to generate an image representing the moisture concentration distribution result based on the overlay result file.

[0069] Exemplarily, in order to make the superimposed result file a normalized result file, the results of each material need to be superimposed according to the saturation concentration ratio. After determining the physical diffusion result file and the chemical adsorption result file, the plug-in module 150 can generate the superimposed result file by the following formula (6):

[0070]

[0071] Where C represents the moisture concentration of the embedded component packaging structure, C1 represents the moisture concentration of the embedded component packaging structure during the physical diffusion stage, and C sat1 represents the moisture saturation concentration of the embedded component packaging structure during the physical diffusion stage, C sat2 C2 represents the moisture saturation concentration of the embedded component packaging structure during the chemical adsorption stage, and C3 represents the moisture concentration of the embedded component packaging structure during the chemical adsorption stage.

[0072] Specifically, the above formula (6) is a superposition process of a single material, but the embedded component packaging structure includes multiple materials. The following takes the embedded component packaging structure including two materials as an example. Figure 5 The superposition process of moisture concentration of each material is explained.

[0073] like Figure 5 As shown, in the physical diffusion stage (Stage 1), the moisture saturation concentration of the first material (MAT1) is C sat11 , the moisture concentration determined by simulation is C 11, the moisture saturation concentration of the second material (MAT2) is C sat21 , the moisture concentration determined by simulation is C 21 ; In the chemical adsorption stage (Stage 2), the moisture saturation concentration of MAT1 is C sat12 , the moisture concentration determined by simulation is C 12 , the moisture saturation concentration of MAT2 is C sat22 , the moisture concentration determined by simulation is C 22 , then the total moisture concentration C of MAT1 总1 It can be expressed by the following formula (7): the total moisture concentration C of MAT2 总2 It can be expressed by the following formula (8).

[0074]

[0075] Specifically, after the plug-in module 150 receives the result values ​​of each material in the embedded component packaging structure in the two diffusion stages from the solver 140, the total moisture concentration of each material can be determined by the above formula (7) or formula (8), and then the superposition result file can be obtained. Then, with the help of the post-processing framework (Data Processing Framework, DPF) provided by ANSYS, the superposition result file and the grid data can be converted into a field (Feild), and the results of multiple time steps can be assembled to obtain a field (Fields Container). By obtaining the grid of the same material, the grid result is extracted, and the operator is used to process it, and then the processing result is sent to the post-processing module 122 to display the result cloud map of the moisture concentration distribution of the embedded component packaging structure.

[0076] For example, Figure 3 An image showing the moisture concentration distribution results of the third dielectric layer of the embedded component packaging structure determined by simulation based on the double-order diffusion theory model after moisture intrusion for 6 hours at 85 degrees Celsius (℃) and 85% relative humidity (RH). Figure 4 The image shows the moisture concentration distribution results of the third dielectric layer of the embedded component packaging structure determined by the Fick diffusion theory model simulation after moisture intrusion for 6 hours under an environment of 85°C and 85% RH. Figure 4 It can be seen that after 6 hours of moisture diffusion, the moisture on path 1 (Path 1) has not diffused into the embedded component packaging structure. Figure 3 It can be seen that after 6 hours of moisture diffusion, the moisture on Path 1 has seriously invaded the interior of the embedded component packaging structure.

[0077] In order to verify the accuracy of the simulation results, the degree of moisture intrusion of the embedded component packaging structure after moisture diffusion for 6 hours in an environment of 85°C and 85% RH is determined through experiments. Specifically, in actual situations, the intensity of the deuterium element can be measured to determine the ratio of the hydrogen element to the deuterium element, and then the degree of moisture intrusion can be determined by the ratio of the hydrogen element to the deuterium element.

[0078] In one example, after placing the actual embedded component packaging structure in an environment of 85° C. and 85% RH for moisture diffusion for 6 hours, the measured hydrogen-deuterium ratio (H / D) at various positions on Path 1 can be shown in Table 2.

[0079] Table 2 Hydrogen-deuterium ratio at various distances

[0080] Distance(mm) Hydrogen-deuterium ratio 0-0.8 1149 0.8-1.6 1396 1.6-2.4 2414 2.4-3.2 1746 3.2-3.6 716

[0081] It can be seen from Table 2 that the hydrogen-deuterium ratios obtained from the tests at various locations on Path 1 are significantly smaller than the hydrogen-deuterium ratios in nature (7000), indicating that moisture has invaded the interior of the embedded component packaging structure. The moisture concentration distribution results of the embedded component packaging structure determined by the simulation based on the double-order diffusion theory model are more accurate.

[0082] In this embodiment, the moisture diffusion theoretical model is represented by a double-order diffusion theoretical model, which can take into account the situation in which moisture chemically adsorbs and generates bound water during the diffusion process of polymer materials. This can make the simulation results of moisture diffusion closer to the actual situation, thereby more accurately guiding the packaging structure process design and packaging material selection, and reducing reliability problems caused by moisture.

[0083] In some optional implementations, in order to simplify calculations and improve simulation efficiency, the diffusion coefficient and the moisture saturation concentration may be considered to be unaffected by temperature, and the diffusion coefficient and the moisture saturation concentration may be set to fixed values.

[0084] In other optional embodiments, in order to further improve the accuracy of the moisture concentration simulation results, it is considered that the diffusion coefficient and / or moisture saturation concentration varies with temperature, that is, the diffusion coefficient and / or moisture saturation concentration are determined based on the temperature of the embedded component packaging structure, and the diffusion coefficient and / or moisture saturation concentration are set as a function of temperature. The relationship between the diffusion coefficient, moisture saturation concentration and temperature can be determined through experiments.

[0085] For example, the relationship between the diffusion coefficient and temperature can be expressed by the following formula (9):

[0086]

[0087] Where D0 is a constant used to represent the maximum diffusion rate, and the unit is m 2 / s; ED is the diffusion coefficient activation energy, with the unit of J / mol; R is the ideal gas constant, R=8.314J / (mol·K); T is the absolute temperature, with the unit of K.

[0088] Exemplarily, without considering the temperature, the solver 140 is also configured with a wet stress theoretical model, which is used to characterize the change process of the wet stress of the embedded component packaging structure with the moisture concentration. The solver 140 is also used to generate a second result file based on the wet stress theoretical model and the first result file, and send the second result file to the post-processing module 122. The post-processing module 122 is also used to generate an image characterizing the wet stress distribution result based on the second result file.

[0089] Specifically, after determining the moisture concentration distribution result (i.e., the first result file) of the embedded component packaging structure based on the wet diffusion theoretical model, the concentration field can be used as the initial condition, and the wet stress theoretical model can be solved by the solver 140 to obtain the second result file, and then the second result file is processed by the post-processing module to obtain an image of the wet stress distribution result, which is convenient for users to understand the wet stress at various positions of the embedded component packaging structure, analyze problems such as stress mismatch and interface stratification, and thus accurately guide the packaging structure design.

[0090] Exemplarily, the wet stress theoretical model can be expressed by the following formula (10):

[0091] {ε}={ε el}+{ε di}=[E] -1 σ+{β}ΔC (10)

[0092] Where ε represents the wet stress, ε el represents the elastic strain, ε di represents the moisture expansion strain, [E] represents the stress-strain matrix of the material, σ represents the total strain vector, and β represents the moisture expansion coefficient.

[0093] Exemplarily, in the case of considering temperature, the solver 140 is also configured with a moisture-heat coupling stress theoretical model, which is used to characterize the variation process of the moisture-heat coupling stress of the embedded component packaging structure with the moisture concentration and temperature. The solver 140 is also used to generate a third result file based on the moisture-heat coupling stress theoretical model and the first result file, and send the third result file to the post-processing module 122, and the post-processing module 122 is also used to generate an image representing the moisture-heat coupling stress distribution result based on the third result file.

[0094] Specifically, after determining the moisture concentration distribution result (i.e., the first result file) of the embedded component packaging structure based on the moisture diffusion theoretical model, the concentration field can be used as the initial condition, and the moisture-heat coupling stress theoretical model can be solved by the solver 140 to obtain a third result file, and then the third result file is processed by the post-processing module to obtain an image of the moisture-heat coupling stress distribution result, which is convenient for users to understand the moisture-heat coupling stress at various positions of the embedded component packaging structure, analyze problems such as stress mismatch and interface stratification, and thus accurately guide the packaging structure design.

[0095] For example, the theoretical model of the hygrothermal coupling stress can be expressed by the following formula (11):

[0096] {ε(T)}={ε el}+{ε th}+{ε di}=[E] -1 {σ}+αΔT+{β}ΔC (11)

[0097] Where ε(T) represents the heat-moisture coupling stress, ε th represents thermal expansion strain, and α represents the thermal expansion coefficient.

[0098] In some optional embodiments, the solver 140 is also configured with a reflow vapor pressure stress theoretical model, which is used to characterize the variation of the moisture-heat coupling stress of the embedded component packaging structure with moisture concentration, temperature and vapor pressure. The solver 140 is also used to generate a fourth result file based on the reflow vapor pressure stress theoretical model and the third result file, and send the fourth result file to the post-processing module 122, which is also used to generate an image characterizing the reflow vapor pressure stress distribution result based on the fourth result file.

[0099] Specifically, after determining the moisture-heat coupling stress distribution result (i.e., the third result file) of the embedded component packaging structure based on the moisture-heat coupling stress theoretical model, the moisture-heat coupling stress can be used as the initial condition, and the reflux vapor pressure stress theoretical model can be solved by the solver 140 to obtain a fourth result file, and then the fourth result file is processed by the post-processing module to obtain an image of the reflux vapor pressure distribution result.

[0100] During high-temperature processes such as reflow soldering, high temperatures may cause the water in the gaps or interfaces inside the package to evaporate, resulting in vapor pressure, causing the interface to delaminate or even burst. After determining the moisture-heat coupling stress, vapor pressure simulation can be performed to simulate the reflow process, solve the maximum stress of the package structure before cracks appear, and predict the possible failure position of the package structure.

[0101] In one example, the strain caused by steam pressure is regarded as the volume change caused by the internal force loading of the embedded component packaging structure, so that the steam pressure strain is obtained according to the relevant mechanical theory, and it is equivalent to the thermal expansion coefficient to facilitate simulation calculation. Its mathematical expression can be expressed by the following formula (12):

[0102]

[0103] Among them, α vapor is the equivalent vapor pressure expansion coefficient; E is Young's modulus; v is Poisson's ratio; P represents pressure.

[0104] Exemplarily, the wet diffusion simulation device also includes a wizard module, which is used to indicate the simulation process. The user only needs to input the packaging structure, boundary conditions and moisture properties according to the instructions to complete the simulation and determine the moisture concentration distribution results, wet stress distribution results, wet-heat coupling stress distribution results and / or reflow vapor pressure distribution results of the packaging structure.

[0105] The present invention also provides a method for simulating moisture distribution, which can be used for a computer device equipped with the moisture diffusion simulation device provided by any of the above embodiments. Figure 6 is a flow chart of a moisture distribution simulation method provided by an embodiment of the present invention, such as Figure 6 As shown, the method comprises the following steps:

[0106] Step S601 : inputting an embedded component packaging structure into a wet diffusion simulation device, or generating an embedded component packaging structure based on the wet diffusion simulation device.

[0107] Among them, the wet diffusion simulation device is the wet diffusion simulation device provided by any of the above embodiments.

[0108] Specifically, the user can import the embedded component packaging structure into the geometric structure module 130 of the wet diffusion simulation device through the GUI interface, and the user can also create and generate the embedded component packaging structure in the geometric structure module of the wet diffusion simulation device through the GUI interface.

[0109] Step S602: input moisture boundary conditions and moisture properties corresponding to the embedded component packaging structure into a moisture diffusion simulation device.

[0110] Specifically, the user can determine the moisture boundary conditions and moisture properties of the embedded component packaging structure based on the simulation requirements and the external test environment, and then input the moisture boundary conditions and moisture properties into the moisture diffusion simulation device based on the GUI interface. The plug-in module 150 of the moisture diffusion simulation device determines the moisture boundary conditions and calls the corresponding moisture properties from the material library based on the user's operation.

[0111] Step S603, determining the moisture concentration distribution result of the embedded component packaging structure based on the output of the moisture diffusion simulation device.

[0112] In one example, after the moisture diffusion theoretical model is selected, the output of the moisture diffusion simulation device may be determined as a moisture concentration distribution result of the embedded component packaging structure.

[0113] Specifically, after receiving the embedded component packaging structure, the geometric structure module 130 of the wet diffusion simulation device transmits the embedded component packaging structure to the meshing module 121, and the meshing module 121 meshes the embedded component packaging structure based on the user settings to generate a finite element mesh. The plug-in module 150 reads the moisture properties corresponding to each material layer of the embedded component packaging structure from the material library, and after receiving the moisture boundary conditions corresponding to the embedded component packaging structure, the moisture properties corresponding to each material layer of the embedded component packaging structure are converted into a first command stream and the moisture boundary conditions are converted into a second command stream and sent to the solver 140. The solver 140 solves the moisture diffusion theoretical model based on the first command stream and the second command stream to obtain the solution result (i.e., the first result file), and sends the solution result to the post-processing module 122 through the plug-in module 150 for post-processing, generates an image representing the moisture concentration distribution result, and outputs it.

[0114] In some optional embodiments, after selecting the wet stress theoretical model, the image of the wet stress distribution results can be determined based on the output of the wet diffusion simulation device; after selecting the wet heat coupling stress theoretical model, the image of the wet heat coupling stress distribution results can be determined based on the output of the wet diffusion simulation device; after selecting the reflux vapor pressure stress theoretical model, the image of the reflux vapor pressure stress distribution results can be determined based on the output of the wet diffusion simulation device.

[0115] An embodiment of the present invention further provides a computer device having the wet diffusion simulation device provided by any one of the above embodiments.

[0116] See also Figure 7 , Figure 7 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 7As shown, the computer device includes: one or more processors 710, memory 720, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 7 A processor 710 is taken as an example.

[0117] The processor 710 may be a central processing unit, a network processor or a combination thereof. The processor 710 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable logic gate array, a general purpose array logic or any combination thereof.

[0118] The memory 720 stores instructions executable by at least one processor 710, so that the at least one processor 710 executes the method shown in the above embodiment.

[0119] The memory 720 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 720 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 720 may optionally include a memory remotely arranged relative to the processor 710, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0120] The memory 720 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 720 may also include a combination of the above types of memory.

[0121] The computer device also includes an input device 730 and an output device 740. The processor 710, the memory 720, the input device 730 and the output device 740 may be connected via a bus or other means. Figure 7 The example of connecting through bus is taken in the following.

[0122] The input device 730 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 740 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0123] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0124] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0125] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0126] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0127] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0128] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A wet diffusion simulation device, characterized in that: It includes an engineering project module, a mechanical design platform, a geometric structure module, a solver and a plug-in module. The mechanical design platform includes a meshing module and a post-processing module. The engineering project module is configured with a material library that characterizes the moisture properties of various materials. The solver is configured with a moisture diffusion theoretical model, and the moisture diffusion theoretical model is used to characterize the diffusion process of moisture in the packaging structure of embedded components. The geometric structure module is used to receive or generate the embedded component packaging structure, and send the embedded component packaging structure to the meshing module, and the meshing module is used to mesh the embedded component packaging structure and send the meshed embedded component packaging structure to the solver; The plug-in module is used to read the moisture properties corresponding to the embedded component packaging structure from the material library and receive moisture boundary conditions, to convert the moisture properties into a first command stream and to convert the moisture boundary conditions into a second command stream, and to send the first command stream and the second command stream to the solver; The solver is used to generate a first result file based on the moisture diffusion theoretical model, the first command stream and the second command stream, and send the first result file to the post-processing module through the plug-in module. The post-processing module is used to generate an image representing the moisture concentration distribution result based on the first result file.

2. The wet diffusion simulation device according to claim 1, characterized in that: The moisture diffusion theoretical model is a double-order diffusion theoretical model, which includes a physical diffusion model and a chemical adsorption model, and the first result file includes a physical diffusion result file and a chemical adsorption result file; The solver is used to generate the physical diffusion result file based on the physical diffusion model, the first command stream and the second command stream, and to generate the chemical adsorption result file based on the chemical adsorption model, the first command stream and the second command stream, and to send the physical diffusion result file and the chemical adsorption result file to the plug-in module; The plug-in module generates an overlay result file based on the physical diffusion result file and the chemical adsorption result file, and sends the overlay result file to the post-processing module, which is used to generate an image representing the moisture concentration distribution result based on the overlay result file.

3. The wet diffusion simulation device according to claim 2, characterized in that: The double-order diffusion theory model is expressed by the following formula: Among them, M t represents the moisture content of the embedded component packaging structure at time t, M sat,1 represents the saturated mass of the embedded component packaging structure in the physical diffusion stage, D1 represents the diffusion coefficient in the physical diffusion stage, t represents time, h represents the thickness of the embedded component packaging structure, M sat,2 represents the saturated mass of the embedded component packaging structure in the chemical adsorption stage, and D2 represents the diffusion coefficient in the chemical adsorption stage.

4. The wet diffusion simulation device according to claim 3, characterized in that: The plug-in module generates a superposition result file based on the physical diffusion result file and the chemical adsorption result file by the following formula: Wherein, C represents the moisture concentration of the embedded component packaging structure, C1 represents the moisture concentration of the embedded component packaging structure in the physical diffusion stage, and C sat1 represents the moisture saturation concentration of the embedded component packaging structure in the physical diffusion stage, C sat2 represents the moisture saturation concentration of the embedded component packaging structure in the chemical adsorption stage, and C2 represents the moisture concentration of the embedded component packaging structure in the chemical adsorption stage.

5. The wet diffusion simulation device according to claim 4, characterized in that: The diffusion coefficient and / or the moisture saturation concentration are determined based on temperature.

6. The wet diffusion simulation device according to any one of claims 1 to 5, characterized in that: The solver is also configured with a wet stress theoretical model, which is used to characterize the variation process of wet stress of the embedded component packaging structure with moisture concentration; The solver is further configured to generate a second result file based on the wet stress theoretical model and the first result file, and send the second result file to the post-processing module. The post-processing module is further configured to generate an image representing wet stress distribution results based on the second result file.

7. The wet diffusion simulation device according to any one of claims 1 to 5, characterized in that: The solver is also configured with a moisture-heat coupling stress theoretical model, which is used to characterize the variation process of the moisture-heat coupling stress of the embedded component packaging structure with moisture concentration and temperature; The solver is also used to generate a third result file based on the moist-thermal coupling stress theoretical model and the first result file, and send the third result file to the post-processing module. The post-processing module is also used to generate an image representing the moist-thermal coupling stress distribution result based on the third result file.

8. The wet diffusion simulation device according to claim 7, characterized in that: The solver is also configured with a reflow vapor pressure stress theoretical model, which is used to characterize the variation of the moisture-heat coupling stress of the embedded component packaging structure with moisture concentration, temperature and vapor pressure; The solver is also used to generate a fourth result file based on the reflux steam pressure stress theoretical model and the third result file, and send the fourth result file to the post-processing module. The post-processing module is also used to generate an image characterizing the reflux steam pressure stress distribution result based on the fourth result file.

9. A method for simulating moisture distribution, characterized in that: The method comprises: Inputting an embedded component packaging structure into a wet diffusion simulation device, or generating the embedded component packaging structure based on the wet diffusion simulation device, wherein the wet diffusion simulation device is the wet diffusion simulation device according to any one of claims 1 to 8; Inputting moisture boundary conditions and moisture properties corresponding to the embedded component packaging structure into the moisture diffusion simulation device; Based on the output of the moisture diffusion simulation device, a moisture concentration distribution result of the embedded component packaging structure is determined.

10. A computer device, characterized in that: The wet diffusion simulation device comprises the wet diffusion simulation device according to any one of claims 1 to 8.

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