Simulation method, device and equipment for evaluating reliability of surface acoustic wave filter and medium

Abstract

The invention discloses a simulation method, device and equipment for evaluating the reliability of a surface acoustic wave filter and a medium. The simulation method comprises the following steps: establishing a three-dimensional geometric model of the surface acoustic wave filter; material parameters of a substrate stress constitutive model are determined according to the material of the substrate, material parameters of a plastic package cover stress constitutive model are determined according to the material of the plastic package cover, material parameters of a solder ball stress constitutive model are determined according to the material of the solder ball, and material parameters of a chip stress constitutive model are determined according to the material of the chip; determining a thermal boundary condition of the three-dimensional geometric model according to an actual temperature impact experiment environment; determining a fixed constraint condition of the three-dimensional geometric model according to an application scene of the surface acoustic wave filter; performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter; and performing reliability evaluation on the surface acoustic wave filter according to the stress distribution information of the surface acoustic wave filter. The cost for evaluating the reliability of the surface acoustic wave filter can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of surface acoustic wave filters, and in particular to a simulation method, device, equipment and medium for reliability evaluation of surface acoustic wave filters. Background Art

[0002] In order to meet the market demand for low cost, small size and multi-function of electronic products such as mobile phones, the manufacturing and packaging of electronic components are developing rapidly towards miniaturization. At present, the most common packaging method for surface acoustic wave filters in the market is chip size packaging (CSP). In CSP packaging, due to the differences in material parameters of the substrate, solder balls, chips, plastic cover and other parts of the surface acoustic wave filter, temperature changes in long-term operation will cause stress mismatch between the materials of each part, and cyclic changes in temperature will cause cyclic changes in stress.

[0003] Since the solder ball is the weakest part of the entire SAW filter, long-term stress cycling will cause cracks in the solder ball first. The existence of cracks will cause the electrical performance of the SAW filter to fail. Therefore, the reliability of the solder ball in the SAW filter is an important criterion for judging the reliability of the entire SAW filter.

[0004] The commonly used reliability assessment method is the temperature shock rapid test method. Specifically, the surface acoustic wave filter is first placed in a temperature box with a temperature range of -55°C and 125°C for a single cycle time of one hour. After a certain number of thermal cycles, the device is then tested for electrical properties and polished. Finally, the reliability of the surface acoustic wave filter is assessed by checking whether the device solder balls have cracks. However, the above method has a high time cost and is not conducive to improving R&D efficiency. Summary of the invention

[0005] The present invention provides a simulation method, device, equipment and medium for reliability assessment of a surface acoustic wave filter, so as to solve the problem that the existing reliability assessment method of the surface acoustic wave filter is high in cost and unfavorable for improving research and development efficiency.

[0006] In a first aspect, an embodiment of the present invention provides a simulation method for reliability evaluation of a surface acoustic wave filter, wherein the surface acoustic wave filter includes a substrate, a chip, a plastic cover, and solder balls, and the simulation method includes:

[0007] Establishing a three-dimensional geometric model of a surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model and a solder ball stress constitutive model;

[0008] Determine the material parameters of the stress constitutive model of the substrate according to the material of the substrate, determine the material parameters of the stress constitutive model of the plastic cover according to the material of the plastic cover, determine the material parameters of the stress constitutive model of the solder ball according to the material of the solder ball, and determine the material parameters of the stress constitutive model of the chip according to the material of the chip;

[0009] Determining the thermal boundary conditions of the three-dimensional geometric model according to the actual temperature shock test environment;

[0010] Determining fixed constraint conditions of the three-dimensional geometric model according to an application scenario of the surface acoustic wave filter;

[0011] Performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter;

[0012] Reliability evaluation is performed on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

[0013] Optionally, performing reliability assessment on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter includes:

[0014] Determining the maximum shear stress of the solder ball according to the stress distribution information of the surface acoustic wave filter;

[0015] Whether the solder ball is reliable is determined according to the maximum shear stress and yield limit of the solder ball.

[0016] Optionally, determining the maximum shear stress of the solder ball according to the stress distribution information of the surface acoustic wave filter includes:

[0017] Determine the maximum principal stress and the minimum principal stress of the solder ball according to the stress distribution information of the surface acoustic wave filter;

[0018] The maximum shear stress is determined based on the maximum principal stress and the minimum principal stress.

[0019] Optionally, determining the maximum shear stress according to the maximum principal stress and the minimum principal stress includes:

[0020] The maximum shear stress is determined according to the maximum principal stress, the minimum principal stress and the following corresponding relationship:

[0021] ;

[0022] in, represents the maximum shear stress, represents the maximum principal stress, represents the minimum principal stress.

[0023] Optionally, determining whether the solder ball is reliable according to the maximum shear stress and yield limit of the solder ball includes:

[0024] If the maximum shear stress of the solder ball is greater than or equal to the yield limit, the solder ball is determined to be unreliable;

[0025] If the maximum shear of the solder ball is less than the yield limit, the solder ball is determined to be reliable.

[0026] Optionally, determining material parameters of the stress constitutive model of the substrate according to the material of the substrate includes:

[0027] If the material of the substrate includes a tangent anisotropic material, determining the material parameters of the stress constitutive model of the substrate includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the substrate;

[0028] Determining material parameters of the stress constitutive model of the plastic cover according to the material of the plastic cover includes:

[0029] If the material of the plastic cover includes a tangent anisotropic material, determining the material parameters of the stress constitutive model of the plastic cover includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the plastic cover;

[0030] Determining material parameters of the solder ball stress constitutive model according to the material of the solder ball includes:

[0031] If the material of the solder ball includes an isotropic material, determining the material parameters of the solder ball stress constitutive model includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the solder ball;

[0032] Determining material parameters of the chip stress constitutive model according to the material of the chip includes:

[0033] If the material of the chip includes anisotropic material, the material parameters of the chip stress constitutive model are determined according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient variation matrix corresponding to the cut of the anisotropic material of the chip.

[0034] Optionally, determining material parameters of the chip stress constitutive model according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient variation matrix corresponding to the cut of the anisotropic material of the chip includes:

[0035] Determine an elastic matrix of the chip according to the Euler angles, Bond stress transformation matrix and Bond strain transformation matrix corresponding to the cut type of the anisotropic material of the chip;

[0036] The thermal expansion coefficient matrix of the chip is determined according to the Euler angles corresponding to the cut of the anisotropic material of the chip and the thermal expansion coefficient variation matrix, wherein the material parameters of the chip stress constitutive model include the elastic matrix and the thermal expansion coefficient matrix.

[0037] In a second aspect, an embodiment of the present invention provides a simulation device for reliability evaluation of a surface acoustic wave filter, comprising:

[0038] A three-dimensional geometric model building unit, used to build a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model and a solder ball stress constitutive model;

[0039] a material parameter determination unit, used to determine the material parameters of the substrate stress constitutive model according to the material of the substrate, determine the material parameters of the plastic cover stress constitutive model according to the material of the plastic cover, determine the material parameters of the solder ball stress constitutive model according to the material of the solder ball, and determine the material parameters of the chip stress constitutive model according to the material of the chip;

[0040] A thermal boundary condition determination unit, used to determine the thermal boundary conditions of the three-dimensional geometric model according to an actual temperature shock test environment;

[0041] A fixed constraint condition determination unit, used to determine the fixed constraint conditions of the three-dimensional geometric model according to the application scenario of the surface acoustic wave filter;

[0042] A simulation unit, used for performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter;

[0043] A reliability evaluation unit is used to perform reliability evaluation on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

[0044] In a third aspect, an embodiment of the present invention provides an electronic device, the electronic device comprising:

[0045] one or more processors;

[0046] a storage device for storing one or more programs,

[0047] When the one or more programs are executed by the one or more processors, the one or more processors implement the simulation method as described in the first aspect.

[0048] In a fourth aspect, an embodiment of the present invention provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the simulation method as described in the first aspect.

[0049] Compared with the existing temperature shock rapid test method, the embodiment of the present invention only needs to add the determined material parameters, thermal boundary conditions and fixed constraints to the three-dimensional geometric model and perform finite element stress simulation, so as to determine the reliability evaluation result of the surface acoustic wave filter according to the stress distribution information obtained by the simulation, thereby realizing the reliability evaluation of the surface acoustic wave filter, with low cost, and being able to help designers optimize the solder ball arrangement method and evaluate the reliability of the device in the product design stage, which is conducive to shortening the R&D time and improving the R&D efficiency.

[0050] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 A flow chart of a simulation method for reliability assessment of a surface acoustic wave filter provided by an embodiment of the present invention;

[0053] Figure 2 A schematic structural diagram of a three-dimensional geometric model of a surface acoustic wave filter provided by an embodiment of the present invention;

[0054] Figure 3 A flowchart of another simulation method for surface acoustic wave filter reliability assessment provided by an embodiment of the present invention;

[0055] Figure 4 A flowchart of another simulation method for reliability assessment of a surface acoustic wave filter provided by an embodiment of the present invention;

[0056] Figure 5 A schematic diagram of a solder ball arrangement method of a surface acoustic wave filter provided by an embodiment of the present invention;

[0057] Figure 6 A schematic diagram of the maximum shear stress distribution of a solder ball obtained by using the simulation method provided by an embodiment of the present invention;

[0058] Figure 7 This is the solder ball grinding diagram obtained by using the existing temperature shock rapid test method;

[0059] Figure 8A schematic diagram of the structure of a simulation device for reliability evaluation of a surface acoustic wave filter provided by an embodiment of the present invention;

[0060] Fig. 9 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0061] Explanation of the reference numerals: 10, substrate stress constitutive model; 20, chip stress constitutive model; 30, plastic cover stress constitutive model; 40, solder ball stress constitutive model; 401, solder ball at the lower right corner of the surface acoustic wave filter. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 only 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 ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only used to illustrate the relative positional relationship between the components or components, and does not particularly limit the specific installation orientation of the components or components.

[0064] Figure 1 A flowchart of a simulation method for reliability assessment of a surface acoustic wave filter provided in an embodiment of the present invention. The simulation method in the embodiment of the present invention is applicable to situations where reliability assessment of a surface acoustic wave filter is required. The simulation method can be executed by a simulation device for reliability assessment of a surface acoustic wave filter, which can be implemented in software and / or hardware and specifically configured in an electronic device.

[0065] It should be noted that the surface acoustic wave filter in the embodiment of the present invention includes a substrate, a chip, a plastic cover and solder balls. Figure 1 , the simulation method for reliability evaluation of a surface acoustic wave filter in an embodiment of the present invention comprises:

[0066] S110, establishing a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model, and a solder ball stress constitutive model.

[0067] For example, Figure 2 A three-dimensional geometric model of a surface acoustic wave filter provided in an embodiment of the present invention includes a substrate stress constitutive model 10, a chip stress constitutive model 20, a plastic cover stress constitutive model 30, and a solder ball stress constitutive model 40. The three-dimensional geometric model is established based on an actual surface acoustic wave filter, the substrate stress constitutive model 10 corresponds to the substrate in the surface acoustic wave filter, the chip stress constitutive model 20 corresponds to the chip in the surface acoustic wave filter, the plastic cover stress constitutive model 30 corresponds to the plastic cover in the surface acoustic wave filter, and the solder ball stress constitutive model 40 corresponds to the solder ball in the surface acoustic wave filter.

[0068] S120, determining material parameters of a substrate stress constitutive model according to the material of the substrate, determining material parameters of a plastic cover stress constitutive model according to the material of the plastic cover, determining material parameters of a solder ball stress constitutive model according to the material of the solder ball, and determining material parameters of a chip stress constitutive model according to the material of the chip.

[0069] It is understandable that the difference in materials of various components of the surface acoustic wave filter is a fundamental factor affecting the reliability of the surface acoustic wave filter. Therefore, in order to realize the reliability assessment of the surface acoustic wave filter, it is necessary to set the material parameters of the stress constitutive model corresponding to each component according to the materials of each component in the surface acoustic wave filter.

[0070] S130. Determine the thermal boundary conditions of the three-dimensional geometric model according to the actual temperature shock test environment.

[0071] Exemplarily, the same temperature conditions as those in the actual temperature shock rapid test are added to the three-dimensional geometric model as thermal boundary conditions. Specifically, the highest temperature (e.g., 125°C) and the lowest temperature (e.g., -55°C) of the actual temperature shock test environment are used as thermal boundary conditions of the three-dimensional geometric model.

[0072] S140. Determine fixed constraint conditions of the three-dimensional geometric model according to an application scenario of the surface acoustic wave filter.

[0073] It is understandable that in actual use, the surface acoustic wave filter does not work alone, and often needs to be fixedly constrained to other devices. In order to obtain more accurate stress simulation results and reliability assessment results, it is necessary to set appropriate fixed constraints according to the specific application scenarios of the surface acoustic wave filter. For example, the surface acoustic wave filter is unconstrained and unfixed (that is, the fixed constraint condition is a point constraint), or the surface acoustic wave filter is soldered on the board (that is, the fixed constraint condition is the device pad surface constraint). Different fixed constraints correspond to different stress simulation results and reliability assessment results.

[0074] S150, performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter.

[0075] Exemplarily, after adding determined material parameters, thermal boundary conditions and fixed constraints to the three-dimensional geometric model, finite element stress simulation can be performed on the three-dimensional geometric model to obtain stress distribution information of the surface acoustic wave filter.

[0076] S160 . Perform reliability assessment on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

[0077] Exemplarily, the stress distribution information of the surface acoustic wave filter includes the stress of each solder ball in the surface acoustic wave filter. Whether the solder ball is reliable can be judged according to the stress of each solder ball, and further whether the surface acoustic wave filter is reliable can be judged.

[0078] Compared with the existing temperature shock rapid test method, the embodiment of the present invention only needs to add the determined material parameters, thermal boundary conditions and fixed constraints to the three-dimensional geometric model established according to the surface wave filter, and perform finite element stress simulation, so as to determine the reliability evaluation result of the surface acoustic wave filter according to the stress distribution information obtained by simulation, thereby realizing the reliability evaluation of the surface acoustic wave filter, with low cost, and being able to help designers optimize the solder ball arrangement method and evaluate the reliability of the device in the product design stage, which is conducive to shortening the R&D time and improving the R&D efficiency.

[0079] Figure 3 A flowchart of another simulation method for surface acoustic wave filter reliability assessment provided by an embodiment of the present invention, Figure 3 The embodiment shown in the figure describes in detail how to perform reliability evaluation on the surface acoustic wave filter according to the stress distribution information of the surface acoustic wave filter. Figure 3 , the simulation method for reliability evaluation of a surface acoustic wave filter in an embodiment of the present invention comprises:

[0080] S210, establishing a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model, and a solder ball stress constitutive model.

[0081] S220, determining material parameters of a substrate stress constitutive model according to the material of the substrate, determining material parameters of a plastic cover stress constitutive model according to the material of the plastic cover, determining material parameters of a solder ball stress constitutive model according to the material of the solder ball, and determining material parameters of a chip stress constitutive model according to the material of the chip.

[0082] S230. Determine the thermal boundary conditions of the three-dimensional geometric model according to the actual temperature shock test environment.

[0083] S240. Determine fixed constraint conditions of the three-dimensional geometric model according to an application scenario of the surface acoustic wave filter.

[0084] S250, performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter.

[0085] S260 , determining the maximum shear stress of the solder ball according to the stress distribution information of the surface acoustic wave filter.

[0086] As a feasible implementation method, the maximum shear stress of the solder ball is determined according to the stress distribution information of the surface acoustic wave filter, including: determining the maximum principal stress and the minimum principal stress of the solder ball according to the stress distribution information of the surface acoustic wave filter; determining the maximum shear stress according to the maximum principal stress and the minimum principal stress.

[0087] Specifically, determining the maximum shear stress according to the maximum principal stress and the minimum principal stress includes: determining the maximum shear stress according to the maximum principal stress, the minimum principal stress and the following corresponding relationship:

[0088] ;

[0089] in, represents the maximum shear stress, represents the maximum principal stress, represents the minimum principal stress.

[0090] It should be noted that the stress distribution information determined in step S250 includes the maximum principal stress and the minimum principal stress of each solder ball.

[0091] S270. Determine whether the solder ball is reliable based on the maximum shear stress and yield limit of the solder ball.

[0092] As a feasible implementation method, whether the solder ball is reliable is determined based on the shear stress and yield limit of the solder ball, including: if the maximum shear stress of the solder ball is greater than or equal to the yield limit, the solder ball is determined to be unreliable; if the maximum shear stress of the solder ball is less than the yield limit, the solder ball is determined to be reliable.

[0093] It should be noted that the yield limit refers to the critical point where the material changes from elastic deformation to plastic deformation during the stress process. The yield limit corresponding to the solder ball can be determined based on the material of the solder ball. Those skilled in the art can obtain it by searching, so it will not be elaborated here.

[0094] Exemplarily, as long as it is determined that one solder ball is unreliable, it can be determined that the surface acoustic wave filter is unreliable.

[0095] Compared with the existing simulation solutions for predicting the life of solder balls, the embodiments of the present invention can reduce the requirements on computer computing power by determining whether the solder balls are reliable based on the maximum shear stress and yield limit of the solder balls.

[0096] Figure 4 A flowchart of another simulation method for reliability evaluation of a surface acoustic wave filter provided by an embodiment of the present invention, Figure 4 The embodiment shown in the figure describes in detail how to determine the material parameters of the substrate stress constitutive model according to the material of the substrate, how to determine the material parameters of the plastic cover stress constitutive model according to the material of the plastic cover, how to determine the material parameters of the solder ball stress constitutive model according to the material of the solder ball, and how to determine the material parameters of the chip stress constitutive model according to the material of the chip. Figure 4 , the simulation method for reliability evaluation of a surface acoustic wave filter in an embodiment of the present invention comprises:

[0097] S310, establishing a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model, and a solder ball stress constitutive model.

[0098] S320. If the material of the substrate includes a tangent anisotropic material, the material parameters of the stress constitutive model of the substrate are determined to include the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the substrate; if the material of the plastic cover includes a tangent anisotropic material, the material parameters of the stress constitutive model of the plastic cover are determined to include the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the plastic cover; if the material of the solder ball includes an isotropic material, the material parameters of the stress constitutive model of the solder ball are determined to include the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the solder ball; if the material of the chip includes anisotropic material, the material parameters of the chip stress constitutive model are determined according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient change matrix corresponding to the cut of the anisotropic material of the chip.

[0099] As a feasible implementation method, the material parameters of the chip stress constitutive model are determined according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient change matrix corresponding to the cut of the anisotropic material of the chip, including: determining the elastic matrix of the chip according to the Euler angles, Bond stress transformation matrix and Bond strain transformation matrix corresponding to the cut of the anisotropic material of the chip; determining the thermal expansion coefficient matrix of the chip according to the Euler angles and thermal expansion coefficient change matrix corresponding to the cut of the anisotropic material of the chip, wherein the material parameters of the chip stress constitutive model include the elastic matrix and the thermal expansion coefficient matrix. It should be noted that the material parameters of the chip stress constitutive model include not only the elastic matrix and the thermal expansion coefficient matrix, but also the density and thermal conductivity of the chip.

[0100] For example, commonly used anisotropic materials for chips include lithium tantalate (LiTaO3) and lithium niobate (LiNbO3). Their commonly used cutting types are shown in Table 1 below.

[0101] Table 1

[0102]

[0103] It should be noted that different cutting types correspond to different Euler angles, and those skilled in the art can find the corresponding Euler angles according to the cutting type ( , , ), which will not be elaborated here.

[0104] Elastic parameters and thermal expansion coefficient are key parameters of finite element stress simulation. For chip materials with different tangents, the elastic matrix and thermal expansion coefficient matrix are different. Anisotropic materials with different tangents can be derived using the bond matrix method. The anisotropic elastic modulus and thermal expansion coefficient settings are introduced using the bond matrix conversion algorithm, which is beneficial to improve the accuracy of the simulation.

[0105] The Bond stress transformation matrix is ​​as follows:

[0106] .

[0107] The Bond strain transformation matrix is ​​as follows:

[0108] .

[0109] in:

[0110] .

[0111] .

[0112] .

[0113] .

[0114] .

[0115] .

[0116] .

[0117] .

[0118] .

[0119] .

[0120] According to Hooke's law: ; ; .

[0121] By converting the elastic matrix under different cutting types:

[0122] .

[0123] The thermal expansion coefficient variation matrix is ​​as follows:

[0124] .

[0125] The thermal expansion coefficient matrix under different cutting types is converted into:

[0126] .

[0127] is the anisotropic thermal expansion coefficient matrix.

[0128] After completing the conversion settings of the material parameters of each component in the 3D geometric model, the thermal boundary conditions and the fixed constraint conditions, the stress distribution information of the surface acoustic wave filter under high and low temperature cycles can be simulated by finite element method. The relationship between the temperature, elastic matrix and strain stress is as follows:

[0129] .

[0130] in, , . represents the elastic strain matrix, represents the overall strain matrix, represents the overall strain matrix, represents the thermal strain matrix, represents the stress matrix, represents the elasticity matrix, , , Represents the thermal expansion coefficient in the x, y, and z directions, that is, the matrix The matrix elements on the diagonal of .

[0131] The simulation accuracy can be improved by adding the anisotropic material elastic modulus and thermal expansion coefficient to the simulation settings.

[0132] S330. Determine the thermal boundary conditions of the three-dimensional geometric model according to the actual temperature shock test environment.

[0133] S340. Determine fixed constraint conditions of the three-dimensional geometric model according to an application scenario of the surface acoustic wave filter.

[0134] S350, performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter.

[0135] S360: Perform reliability assessment on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

[0136] Figure 5 A schematic diagram of a solder ball arrangement method of a surface acoustic wave filter provided by an embodiment of the present invention, Figure 6 FIG. 1 is a schematic diagram of the maximum shear stress distribution of a solder ball obtained by using the simulation method provided by an embodiment of the present invention. Figure 6 The numbers in the blue boxes represent the maximum shear stress of the solder balls. Figure 5 and Figure 6 The maximum shear stress of the solder ball 401 at the lower right corner of the surface acoustic wave filter is the largest, and the solder ball 401 at the lower right corner of the surface acoustic wave filter is the weakest and most likely to crack.

[0137] Figure 7 For the solder ball grinding diagram obtained by using the existing temperature shock rapid test method, refer to Figure 5 and Figure 7 From the solder ball grinding diagram corresponding to the solder ball at the lower right corner of the SAW filter, it can be seen that the solder ball at the lower right corner of the SAW filter has obvious cracks. This result is consistent with Figure 6 The simulation results shown are consistent.

[0138] The embodiment of the present invention also provides a simulation device for reliability evaluation of a surface acoustic wave filter. Figure 8 A schematic diagram of a simulation device for reliability evaluation of a surface acoustic wave filter provided by an embodiment of the present invention, referring to Figure 8 , the simulation device comprises:

[0139] The three-dimensional geometric model building unit 410 is used to build a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model and a solder ball stress constitutive model.

[0140] The material parameter determination unit 420 is used to determine the material parameters of the substrate stress constitutive model according to the material of the substrate, determine the material parameters of the plastic cover stress constitutive model according to the material of the plastic cover, determine the material parameters of the solder ball stress constitutive model according to the material of the solder ball, and determine the material parameters of the chip stress constitutive model according to the material of the chip.

[0141] The thermal boundary condition determination unit 430 is used to determine the thermal boundary conditions of the three-dimensional geometric model according to the actual thermal shock test environment.

[0142] The fixed constraint condition determination unit 440 is used to determine the fixed constraint conditions of the three-dimensional geometric model according to the application scenario of the surface acoustic wave filter.

[0143] The simulation unit 450 is used to perform finite element stress simulation on the three-dimensional geometric model to determine the stress distribution information of the surface acoustic wave filter.

[0144] The reliability evaluation unit 460 is used to perform reliability evaluation on the surface acoustic wave filter according to the stress distribution information of the surface acoustic wave filter.

[0145] The simulation device for reliability assessment of a surface acoustic wave filter provided in an embodiment of the present invention can execute the simulation method for reliability assessment of a surface acoustic wave filter provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0146] Fig. 9 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention, Fig. 9 A schematic diagram of the structure of an electronic device 500 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0147] like Fig. 9As shown, the electronic device 500 includes at least one processor 510, and a memory such as ROM 520, RAM 530, etc., which is connected to the at least one processor 510 in communication, wherein the memory stores a computer program that can be executed by at least one processor, and the processor 510 can perform various appropriate actions and processes according to the computer program stored in ROM 520 or the computer program loaded from the storage unit 580 to RAM 530. It should be noted that ROM represents a read-only memory and RAM represents a random access memory. In RAM 530, various programs and data required for the operation of the electronic device 500 can also be stored. The processor 510, ROM 520 and RAM 530 are connected to each other via a bus 540. An I / O interface 550 is also connected to the bus 540. It should be noted that an I / O interface represents an input / output interface.

[0148] A number of components in the electronic device 500 are connected to the I / O interface 550, including: an input unit 560, such as a keyboard, a mouse, etc.; an output unit 570, such as various types of displays, speakers, etc.; a storage unit 580, such as a disk, an optical disk, etc.; and a communication unit 590, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 590 allows the electronic device 500 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0149] The processor 510 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 510 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 510 executes the various methods and processes described above, such as a simulation method for reliability evaluation of a surface acoustic wave filter.

[0150] In some embodiments, the simulation method for the reliability assessment of the surface acoustic wave filter can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 580. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 500 via the ROM 520 and / or the communication unit 590. When the computer program is loaded into the RAM 530 and executed by the processor 510, one or more steps of the simulation method for the reliability assessment of the surface acoustic wave filter described above can be performed. Alternatively, in other embodiments, the processor 510 can be configured to perform the simulation method for the reliability assessment of the surface acoustic wave filter by any other appropriate means (for example, by means of firmware).

[0151] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0152] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0153] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device, or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0154] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0155] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0156] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0157] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0158] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A simulation method for reliability evaluation of a surface acoustic wave filter, wherein the surface acoustic wave filter comprises a substrate, a chip, a plastic cover and solder balls, characterized in that: The simulation method comprises: Establishing a three-dimensional geometric model of a surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model and a solder ball stress constitutive model; Determine the material parameters of the stress constitutive model of the substrate according to the material of the substrate, determine the material parameters of the stress constitutive model of the plastic cover according to the material of the plastic cover, determine the material parameters of the stress constitutive model of the solder ball according to the material of the solder ball, and determine the material parameters of the stress constitutive model of the chip according to the material of the chip; Determining the thermal boundary conditions of the three-dimensional geometric model according to the actual temperature shock test environment; Determining fixed constraint conditions of the three-dimensional geometric model according to an application scenario of the surface acoustic wave filter; Performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter; Reliability evaluation is performed on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

2. The simulation method according to claim 1, characterized in that: The method further comprises: performing reliability evaluation on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter, comprising: Determining the maximum shear stress of the solder ball according to the stress distribution information of the surface acoustic wave filter; Whether the solder ball is reliable is determined according to the maximum shear stress and yield limit of the solder ball.

3. The simulation method according to claim 2, characterized in that: Determining the maximum shear stress of the solder ball according to the stress distribution information of the surface acoustic wave filter includes: Determine the maximum principal stress and the minimum principal stress of the solder ball according to the stress distribution information of the surface acoustic wave filter; The maximum shear stress is determined based on the maximum principal stress and the minimum principal stress.

4. The simulation method according to claim 3, characterized in that: Determining the maximum shear stress according to the maximum principal stress and the minimum principal stress comprises: The maximum shear stress is determined according to the maximum principal stress, the minimum principal stress and the following corresponding relationship: ； in, represents the maximum shear stress, represents the maximum principal stress, represents the minimum principal stress.

5. The simulation method according to claim 2, characterized in that: Determining whether the solder ball is reliable according to the maximum shear stress and yield limit of the solder ball includes: If the maximum shear stress of the solder ball is greater than or equal to the yield limit, the solder ball is determined to be unreliable; If the maximum shear of the solder ball is less than the yield limit, the solder ball is determined to be reliable.

6. The simulation method according to claim 1, characterized in that: Determining material parameters of the stress constitutive model of the substrate according to the material of the substrate includes: If the material of the substrate includes a tangent anisotropic material, determining the material parameters of the stress constitutive model of the substrate includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the substrate; Determining material parameters of the stress constitutive model of the plastic cover according to the material of the plastic cover includes: If the material of the plastic cover includes a tangent anisotropic material, determining the material parameters of the stress constitutive model of the plastic cover includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the plastic cover; Determining material parameters of the solder ball stress constitutive model according to the material of the solder ball includes: If the material of the solder ball includes an isotropic material, determining the material parameters of the solder ball stress constitutive model includes the density, thermal expansion coefficient, thermal conductivity and elastic parameters of the solder ball; Determining material parameters of the chip stress constitutive model according to the material of the chip includes: If the material of the chip includes anisotropic material, the material parameters of the chip stress constitutive model are determined according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient variation matrix corresponding to the cut of the anisotropic material of the chip.

7. The simulation method according to claim 6, characterized in that: The material parameters of the chip stress constitutive model are determined according to the Euler angles, Bond stress transformation matrix, Bond strain transformation matrix and thermal expansion coefficient change matrix corresponding to the cut shape of the anisotropic material of the chip, including: Determine an elastic matrix of the chip according to the Euler angles, Bond stress transformation matrix and Bond strain transformation matrix corresponding to the cut type of the anisotropic material of the chip; The thermal expansion coefficient matrix of the chip is determined according to the Euler angles corresponding to the cut of the anisotropic material of the chip and the thermal expansion coefficient variation matrix, wherein the material parameters of the chip stress constitutive model include the elastic matrix and the thermal expansion coefficient matrix.

8. A simulation device for reliability evaluation of a surface acoustic wave filter, characterized in that: include: A three-dimensional geometric model building unit, used to build a three-dimensional geometric model of the surface acoustic wave filter, wherein the three-dimensional geometric model includes a substrate stress constitutive model, a chip stress constitutive model, a plastic cover stress constitutive model and a solder ball stress constitutive model; a material parameter determination unit, used to determine the material parameters of the substrate stress constitutive model according to the material of the substrate, determine the material parameters of the plastic cover stress constitutive model according to the material of the plastic cover, determine the material parameters of the solder ball stress constitutive model according to the material of the solder ball, and determine the material parameters of the chip stress constitutive model according to the material of the chip; A thermal boundary condition determination unit, used to determine the thermal boundary conditions of the three-dimensional geometric model according to an actual temperature shock test environment; A fixed constraint condition determination unit, used to determine the fixed constraint conditions of the three-dimensional geometric model according to the application scenario of the surface acoustic wave filter; A simulation unit, used for performing finite element stress simulation on the three-dimensional geometric model to determine stress distribution information of the surface acoustic wave filter; A reliability evaluation unit is used to perform reliability evaluation on the surface acoustic wave filter according to stress distribution information of the surface acoustic wave filter.

9. An electronic device, characterized in that: The electronic device comprises: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the simulation method as described in any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the simulation method according to any one of claims 1 to 7 is implemented.

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