WO2024103438A1 - Line impedance calculation method and system for grid shielding structure, device, and medium - Google Patents

Abstract

Disclosed in the present invention are a line impedance calculation method and system for a grid shielding structure, a device, and a medium. First, an escape proportion of a signal escape amount of a grid shielding layer relative to a signal transmission amount of a dielectric-ground layer is calculated on the basis of a conductor width and spacing of the grid shielding layer; then, the signal escape of the grid shielding layer is enabled to be equivalent to an increase of the dielectric thickness of a dielectric layer so as to calculate an equivalent dielectric thickness on the basis of the escape proportion and a dielectric thickness parameter; next, an equivalent dielectric constant of the grid shielding structure relative to a large copper surface shielding layer is calculated on the basis of a network transmission time equivalence principle of a dielectric-ground layer loop; and finally, the line impedance of the grid shielding structure is calculated according to a line width, a copper thickness, the equivalent dielectric thickness, the equivalent dielectric constant, and a classic characteristic impedance calculation formula of the large copper surface shielding layer. A calculation theory and a calculation model of the line impedance of the grid shielding structure are proposed for the first time, so that the line impedance calculation accuracy of the grid shielding structure is greatly improved. The method can be well applied to the impedance line design of the grid shielding structure.

Description

Line impedance calculation method, system, equipment and medium of mesh shielding structure Technical Field

The present invention relates to the technical field of line impedance calculation, and in particular to a line impedance calculation method and system of a grid shielding structure, an electronic device, and a computer-readable storage medium.

Background technique

With the rapid development of the communication industry, the signal transmission speed is getting faster and faster, the working frequency and transmission quality requirements are getting higher and higher, and the types and characteristics of high-speed transmission structures are increasing. In some special PCB boards and other carrier transmission characteristic impedance structures, the original large metal shielding layer structure is changed into a mesh shielding structure. In high-frequency signal transmission, the signal layer (i.e., the conductor layer) and the ground layer (i.e., the shielding layer) are transmitted through high-frequency signal electromagnetic radiation. According to the classic characteristic impedance line transmission and TDR (time domain reflectometry) measurement rules, a high-frequency signal is emitted from the signal line. The signal is not only transmitted forward on the conductor, but also radiated to the ground plane. The induction signal received by the ground plane returns to the measurement end (the measurement and transmission end share the same port). The line impedance value is calculated by the level strength of the transmission signal and the reflected signal. Generally, the reflectivity is expressed by ρ=V _reflected /V _incident , and the measurement impedance Z=Z _ref *(1+ρ)/(1-ρ) is used to measure it. Among them, ρ is the signal reflectivity, V _reflected reflects the level strength of the received signal, V _incident represents the level strength of the transmission signal, and Z _ref represents the standard reference resistance, which is generally 50ohm. For the large metal shielding layer structure, the signal reflection on the large copper surface has a reflection path consistent with the length of the transmission cable, and the reflection signal strength loss mainly comes from the dielectric loss and the conductor surface loss. Therefore, the above-mentioned line impedance value calculation method can be well applied to the large metal shielding layer structure.

However, for the mesh shielding structure, after the mesh shielding layer with holes receives the reflected signal, it is affected by the distribution of the electromagnetic signal line and presents a uniform distribution in the local space, that is, dφ tends to be evenly distributed in a single square area (a+b square size, a represents the conductor width of the mesh shielding layer, b represents the spacing between the conductors in the mesh shielding layer). Therefore, when the signal is transmitted to the shielding layer, part of it is received and returned by the shielding layer, while the other part is radiated and dissipated through the mesh holes, resulting in changes in the return signal strength, which affects the calculation of the impedance value. Therefore, the existing line impedance value calculation method is not suitable for the mesh shielding structure.

Summary of the invention

The present invention provides a line impedance calculation method and system for a mesh shielding structure, an electronic device, and a computer-readable storage medium to solve the technical problem that the existing line impedance value calculation method is not applicable to the mesh shielding structure.

According to one aspect of the present invention, a method for calculating line impedance of a mesh shielding structure is provided, comprising the following contents:

Obtaining the conductor width and spacing of the mesh shielding layer, and calculating the signal dissipation ratio of the mesh shielding layer to the signal transmission amount of the electrical formation;

Obtain the dielectric thickness parameter of the dielectric layer, equate the signal dissipation of the grid shielding layer to the increase in dielectric thickness, and calculate the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter;

Obtain the angle between the impedance line and the horizontal side of the grid shielding layer, the dielectric constant of the dielectric layer, and calculate the equivalent dielectric constant based on the time equivalence principle;

The line width and copper thickness of the impedance line are obtained, and the line impedance is calculated by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.

Furthermore, the dissipation ratio is calculated based on the following formula:

Where η represents the dissipation ratio, a and b represent the conductor width and spacing of the mesh shielding layer, respectively.

Furthermore, the equivalent dielectric thickness is calculated based on the following formula:

Wherein, h′ represents the equivalent dielectric thickness, h represents the dielectric thickness parameter of the dielectric layer, and η represents the dissipation ratio.

Furthermore, the process of calculating the equivalent dielectric constant based on the time equivalence principle is as follows:

In a single grid, the actual transmission time of the electrical signal is t = (1 + cosθ + sinθ) l/v,

c represents the speed of light, _εr represents the dielectric constant of the dielectric layer, θ represents the angle between the impedance line and the horizontal side of the grid shielding layer, and l represents the length of the hypotenuse of a single grid. According to the time equivalence principle, assuming that the transmission length is still 2l, then

ε′ _r represents the equivalent dielectric constant, so

Furthermore, the line impedance of the mesh shielding structure is calculated based on the following formula:

Where _Z1 represents the line impedance, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.

Furthermore, the mesh shielding layer is infinitely wide relative to the impedance line in the width direction; or, the mesh shielding layer is larger than one side of the impedance line by more than 3 mm in the width direction.

In addition, the present invention also provides a line impedance calculation system of a grid shielding structure, comprising:

The first calculation module is used to obtain the conductor width and spacing of the grid shielding layer, and calculate the signal leakage ratio of the grid shielding layer relative to the signal transmission amount of the electrical formation;

The second calculation module is used to obtain the dielectric thickness parameter of the dielectric layer, equate the signal leakage of the grid shielding layer to the increase of dielectric thickness, and calculate the equivalent dielectric thickness based on the leakage ratio and the dielectric thickness parameter;

The third calculation module obtains the angle between the impedance line and the horizontal side of the grid shielding layer and the dielectric constant of the dielectric layer, and calculates the equivalent dielectric constant based on the time equivalence principle;

The fourth calculation module is used to obtain the line width and copper thickness of the impedance line, and calculate the line impedance by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.

Furthermore, the fourth calculation module calculates the line impedance of the mesh shielding structure based on the following formula:

Where _Z1 represents the line impedance, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.

In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

In addition, the present invention also provides a computer-readable storage medium for storing a computer program for calculating the line impedance of a mesh shielding structure, wherein the computer program executes the steps of the method described above when running on a computer.

The present invention has the following effects:

The line impedance calculation method of the mesh shielding structure of the present invention takes into account that after the signal is transmitted to the mesh shielding layer, a part of the signal is received and returned by the mesh shielding layer, while the other part is radiated and dissipated through the mesh holes of the mesh shielding layer, which causes the return signal strength to change, thereby affecting the accuracy of impedance value calculation. Therefore, the present invention first calculates the dissipation ratio of the signal dissipation amount of the mesh shielding layer relative to the signal transmission amount of the electric formation based on the conductor width and spacing of the mesh shielding layer, and then equates the signal dissipation of the mesh shielding layer to the increase in the dielectric thickness of the dielectric layer, thereby calculating the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter, and then calculates the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the equivalent principle of the transmission time of the electric formation loop network, and finally, the line impedance of the mesh shielding structure is calculated by combining the line width, copper thickness, equivalent dielectric thickness, equivalent dielectric constant and the classical characteristic impedance calculation formula of the large copper surface shielding layer of the impedance line. The present invention proposes for the first time a calculation theory and calculation model for the line impedance of a mesh shielding structure, taking into account the influence of the dissipation effect of the mesh shielding layer on the impedance calculation, and by equating the signal dissipation of the mesh shielding layer to an increase in dielectric thickness, and calculating the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the time equivalence principle, the calculation accuracy of the line impedance of the mesh shielding structure is greatly improved, and can be well applied to the impedance line design of the mesh shielding structure.

In addition, the line impedance calculation system, electronic device, and computer-readable storage medium of the grid shielding structure of the present invention also have the above advantages.

In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG. 1 is a schematic cross-sectional view of a mesh shielding structure according to a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram showing that an impedance line is arranged at an angle to a horizontal side of a mesh shielding layer in a preferred embodiment of the present invention.

FIG3 is a flow chart of a method for calculating line impedance of a mesh shielding structure according to a preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of the module structure of a line impedance calculation system of a grid shielding structure according to another embodiment of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

It can be understood that a preferred embodiment of the present invention provides a method for calculating the line impedance of a mesh shielding structure, wherein, as shown in FIG1 and FIG2, the impedance line structure with a mesh shielding structure specifically includes a wiring layer, a dielectric layer and a mesh shielding layer, the wiring layer and the mesh shielding layer are respectively arranged on both sides of the dielectric layer, the wiring layer is designed with an impedance line, generally a single-ended microstrip line, and the mesh shielding layer is an orthogonal square mesh conductor. Optionally, the mesh shielding layer is infinitely wide relative to the impedance line in the width direction; or, the mesh shielding layer is more than 3mm larger than the single side of the impedance line in the width direction. As shown in FIG3, the method for calculating the line impedance of the mesh shielding structure specifically includes the following contents:

Step S1: obtaining the conductor width and spacing of the mesh shielding layer, and calculating the signal dissipation ratio of the mesh shielding layer to the signal transmission amount of the electrical formation;

Step S2: Obtain the dielectric thickness parameter of the dielectric layer, equate the signal dissipation of the grid shielding layer to the increase in dielectric thickness, and calculate the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter;

Step S3: obtaining the angle between the impedance line and the horizontal side of the mesh shielding layer and the dielectric constant of the dielectric layer, and calculating the equivalent dielectric constant based on the time equivalence principle;

Step S4: Obtain the line width and copper thickness of the impedance line, and calculate the line impedance by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.

It can be understood that the line impedance calculation method of the mesh shielding structure of the present embodiment takes into account that after the signal is transmitted to the mesh shielding layer, a part of the signal is received and returned by the mesh shielding layer, while the other part is radiated and dissipated through the mesh holes of the mesh shielding layer, which causes the return signal strength to change, thereby affecting the accuracy of the impedance value calculation. Therefore, the present invention first calculates the signal dissipation ratio of the mesh shielding layer relative to the signal transmission amount of the electric formation based on the conductor width and spacing of the mesh shielding layer, and then equates the signal dissipation of the mesh shielding layer to the increase in the dielectric thickness of the dielectric layer, thereby calculating the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter, and then calculates the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the equivalent principle of the transmission time of the electric formation loop network. Finally, the line impedance of the mesh shielding structure is calculated by combining the line width, copper thickness, equivalent dielectric thickness, equivalent dielectric constant and the classical characteristic impedance calculation formula of the large copper surface shielding layer of the impedance line. The present invention proposes for the first time a calculation theory and calculation model for the line impedance of a mesh shielding structure, taking into account the influence of the dissipation effect of the mesh shielding layer on the impedance calculation, and by equating the signal dissipation of the mesh shielding layer to an increase in dielectric thickness, and calculating the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the time equivalence principle, the calculation accuracy of the line impedance of the mesh shielding structure is greatly improved, and can be well applied to the impedance line design of the mesh shielding structure.

It can be understood that in step S1, since the electromagnetic signal line is evenly distributed in a single grid area (i.e., a square size of a+b) in the grid shielding layer, after the signal is transmitted to the grid shielding layer, the actual signal leakage amount in the single grid area relative to the signal transmission amount is proportional to the receiving area, that is,

Among them, φ ₁ and φ _total represent the signal dissipation and signal transmission respectively, S ₁ and S _total represent the mesh hole area and total area in a single mesh area respectively, and a and b represent the conductor width and spacing of the mesh shielding layer respectively. Therefore, you only need to input the conductor width a and spacing b of the mesh shielding layer to calculate the dissipation ratio based on the following formula:

Here, η represents the escape ratio.

It can be understood that in step S2, according to the classic characteristic impedance calculation formula of the large copper surface shielding layer:

It can be seen that the line impedance _Z0 is inversely proportional to the line width w of the impedance line, the copper thickness t, and the dielectric constant _εr of the dielectric layer, and is proportional to the dielectric thickness h. The larger the dielectric thickness h, the less the signal received. The signal received is directly related to the dielectric layer spacing (i.e., the distance from the dielectric layer to the grid shielding layer). The increase in the grid is equivalent to the increase in the dielectric layer spacing. Therefore, after the large copper surface shielding layer is changed to a grid shielding layer, the radiation dissipation of the signal can be equivalent to the increase in dielectric thickness. Therefore, the dielectric thickness parameters of the input dielectric layer can be specifically calculated based on the following formula to obtain the equivalent dielectric thickness:

Wherein, h′ represents the equivalent dielectric thickness, h represents the dielectric thickness parameter of the dielectric layer, and η represents the dissipation ratio.

It can be understood that in step S3, from the perspective of the electrical formation loop, the characteristic impedance transmission cable still presents a straight line in the dielectric layer, but the transmission path of the mesh shielding layer is affected by the angle between the transmission line and the mesh. Specifically, in a single grid, the signal is transmitted along the right-angled side of the single grid. According to the relationship between the hypotenuse and the short side of the right triangle, the signal transmission length of the mesh shielding layer is: l(cosθ+sinθ), θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, l represents the length of the hypotenuse of the right triangle, and combined with the transmission speed of the electrical signal in the medium:

c represents the speed of light, _εr represents the dielectric constant of the dielectric layer, therefore, the actual transmission time of the electrical signal is t = (1 + cosθ + sinθ)l/v. According to the transmission time equivalence principle of the electrical formation loop network, assuming that the transmission length is still 2l, then

ε′ _r represents the equivalent dielectric constant, which can be calculated as follows:

It can be understood that in step S4, the line width w and copper thickness t of the impedance line are obtained, and the classical characteristic impedance calculation formula of the large copper surface shielding layer structure is corrected in combination with the equivalent dielectric thickness h′ and equivalent dielectric constant ε′ _r calculated previously, and the line impedance calculation formula of the grid shielding structure is obtained as follows:

Wherein, _Z1 represents the line impedance of the mesh shielding structure, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.

It can be understood that in order to verify the calculation accuracy of the line impedance calculation model of the mesh shielding structure of the present invention, actual verification was carried out, and the specific verification case is as follows.

Case 1: Set up a double-sided board, according to the outer microstrip line stacking structure, the line layer design line width is 120um, the transmission cable copper thickness is 50um, the dielectric constant Dk of the dielectric layer material (FR4, epoxy resin) is 4.4, the dielectric thickness is 89um, the conductor width a of the grid shielding layer is 1000um, the spacing b is 1000um, the angles between the transmission line and the horizontal direction of the grid are 0°, 15°, 30°, 45°, 60°, and 90° respectively. The actual measured impedance values simulated by the calculation model are shown in Table 1 below.

Table 1. Comparison of impedance values at different angles

w/um	t/um	h/um	Dk	θ/°	a	b	Z-Calculation	Z measured	Remark
120	50	89	4.4	0	1000	0	46.69	48.32	Conventional large copper surface impedance
120	50	89	4.4	0	1000	1000	57.07	58.84	The
120	50	89	4.4	15	1000	1000	52.547	52.89	The
120	50	89	4.4	30	1000	1000	50.01	51.35	The
120	50	89	4.4	45	1000	1000	49.19	49.58	The
120	50	89	4.4	60	1000	1000	50.00	50.89	The
120	50	89	4.4	90	1000	1000	57.05	57.35	The

Case 2: Set up a double-sided board, according to the outer microstrip line stacking structure, the line layer design line width is 240um, the transmission cable copper thickness is 50um, the dielectric constant Dk of the dielectric layer material (FR4, epoxy resin) is 4.4, the dielectric thickness is 89um, the conductor width a of the grid shielding layer is 1000um, the spacing b is 1000um, 2000um, 3000um, 4000um respectively, the angle between the transmission line and the horizontal direction of the grid is 0°, and the actual measured impedance values simulated by the calculation model are shown in Table 2 below.

Table 2. Effect of different mesh shielding layer spacing on impedance value

w/um	t/um	h/um	Dk	θ/°	a	b	Z-Calculation	Z measured
240	50	89	4.4	0	1000	1000	38.83	40.26
240	50	89	4.4	0	1000	2000	49.66	50.21
240	50	89	4.4	0	1000	3000	58.28	59.39
240	50	89	4.4	0	1000	4000	65.32	63.89

It can be seen from the above practical verification results that the calculation accuracy of the line impedance calculation model of the mesh shielding structure of the present invention is very high.

In addition, as shown in FIG. 4 , another embodiment of the present invention further provides a line impedance calculation system of a mesh shielding structure, preferably using the line impedance calculation method as described above, the system comprising:

The first calculation module is used to obtain the conductor width and spacing of the grid shielding layer, and calculate the signal leakage ratio of the grid shielding layer relative to the signal transmission amount of the electrical formation;

The second calculation module is used to obtain the dielectric thickness parameter of the dielectric layer, equate the signal leakage of the grid shielding layer to the increase of dielectric thickness, and calculate the equivalent dielectric thickness based on the leakage ratio and the dielectric thickness parameter;

The third calculation module obtains the angle between the impedance line and the horizontal side of the grid shielding layer and the dielectric constant of the dielectric layer, and calculates the equivalent dielectric constant based on the time equivalence principle;

The fourth calculation module is used to obtain the line width and copper thickness of the impedance line, and calculate the line impedance by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.

It can be understood that the line impedance calculation system of the mesh shielding structure of the present embodiment takes into account that after the signal is transmitted to the mesh shielding layer, a part of the signal is received and returned by the mesh shielding layer, while the other part is radiated and dissipated through the mesh holes of the mesh shielding layer, which causes the return signal strength to change, thereby affecting the accuracy of the impedance value calculation. Therefore, the present invention first calculates the dissipation ratio of the signal dissipation amount of the mesh shielding layer relative to the signal transmission amount of the electrical formation based on the conductor width and spacing of the mesh shielding layer, and then equates the signal dissipation of the mesh shielding layer to the increase in the dielectric thickness of the dielectric layer, thereby calculating the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter, and then calculating the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the time equivalence principle. Finally, the line impedance of the mesh shielding structure is calculated by combining the line width, copper thickness, equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula of the large copper surface shielding layer of the impedance line. The present invention proposes for the first time a calculation theory and calculation model for the line impedance of a mesh shielding structure, taking into account the influence of the dissipation effect of the mesh shielding layer on the impedance calculation, and by equating the signal dissipation of the mesh shielding layer to an increase in dielectric thickness, and calculating the equivalent dielectric constant of the mesh shielding structure compared to the large copper surface shielding layer based on the time equivalence principle, the calculation accuracy of the line impedance of the mesh shielding structure is greatly improved, and can be well applied to the impedance line design of the mesh shielding structure.

It can be understood that the first calculation module specifically calculates the dissipation ratio based on the following formula:

Where η represents the dissipation ratio, a and b represent the conductor width and spacing of the mesh shielding layer, respectively.

It can be understood that the second calculation module calculates the equivalent dielectric thickness based on the following formula:

Wherein, h′ represents the equivalent dielectric thickness, h represents the dielectric thickness parameter of the dielectric layer, and η represents the dissipation ratio.

It can be understood that the third calculation module calculates the equivalent dielectric constant based on the following formula:

Among them, ε′ _r represents the equivalent dielectric constant, ε _r represents the dielectric constant of the dielectric layer, and θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer.

It can be understood that the fourth calculation module calculates the line impedance of the mesh shielding structure based on the following formula:

Where _Z1 represents the line impedance, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.

It can be understood that each module in the system of this embodiment corresponds to each step of the above method embodiment, so the specific calculation principle of each module will not be repeated here, and reference can be made to the above method embodiment.

In addition, another embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

In addition, another embodiment of the present invention further provides a computer-readable storage medium for storing a computer program for calculating the line impedance of a mesh shielding structure, wherein the computer program executes the steps of the method described above when running on a computer.

The general form of computer readable storage media includes: floppy disk, flexible disk, hard disk, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with a pattern of holes, random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), flash erasable programmable read-only memory (FLASH-EPROM), any other memory chip or cartridge, or any other medium that can be read by a computer. Instructions can further be transmitted or received by a transmission medium. The term transmission medium can include any tangible or intangible medium that can be used to store, encode or carry instructions for execution by a machine, and includes digital or analog communication signals or intangible media that facilitate communication of the above instructions. Transmission media include coaxial cables, copper wires and optical fibers, which include the wires of a bus used to transmit a computer data signal.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

The present application is described with reference to the flowchart and/or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each process and/or box in the flowchart and/or block diagram, and the combination of the process and/or box in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one process or multiple processes in the flowchart and/or one box or multiple boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims (10)

1. A method for calculating line impedance of a mesh shielding structure, characterized by comprising the following contents:

   Obtaining the conductor width and spacing of the mesh shielding layer, and calculating the signal dissipation ratio of the mesh shielding layer to the signal transmission amount of the electrical formation;

   Obtain the dielectric thickness parameter of the dielectric layer, equate the signal dissipation of the grid shielding layer to the increase in dielectric thickness, and calculate the equivalent dielectric thickness based on the dissipation ratio and the dielectric thickness parameter;

   Obtain the angle between the impedance line and the horizontal side of the grid shielding layer, the dielectric constant of the dielectric layer, and calculate the equivalent dielectric constant based on the time equivalence principle;

   The line width and copper thickness of the impedance line are obtained, and the line impedance is calculated by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.
2. The line impedance calculation method of the mesh shielding structure according to claim 1 is characterized in that the dissipation ratio is calculated based on the following formula:

   

   Where η represents the dissipation ratio, a and b represent the conductor width and spacing of the mesh shielding layer, respectively.
3. The line impedance calculation method of the mesh shielding structure according to claim 1 is characterized in that the equivalent dielectric thickness is calculated based on the following formula:

   

   Wherein, h′ represents the equivalent dielectric thickness, h represents the dielectric thickness parameter of the dielectric layer, and η represents the dissipation ratio.
4. The line impedance calculation method of the mesh shielding structure according to claim 1 is characterized in that the process of calculating the equivalent dielectric constant based on the time equivalence principle is specifically:

   In a single grid, the actual transmission time of the electrical signal is t = (1 + cosθ + sinθ) l/v,

   

   c represents the speed of light, _εr represents the dielectric constant of the dielectric layer, θ represents the angle between the impedance line and the horizontal side of the grid shielding layer, and l represents the length of the hypotenuse of a single grid. According to the time equivalence principle, assuming that the transmission length is still 2l, then

   

   ε′ _r represents the equivalent dielectric constant, so

   
5. The line impedance calculation method of the mesh shielding structure according to claim 1 is characterized in that the line impedance of the mesh shielding structure is calculated based on the following formula:

   

   Where _Z1 represents the line impedance, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.
6. The line impedance calculation method of the mesh shielding structure as described in claim 1 is characterized in that the mesh shielding layer is infinitely wide in the width direction relative to the impedance line; or, the mesh shielding layer is more than 3 mm larger than one side of the impedance line in the width direction.
7. A line impedance calculation system of a mesh shielding structure, characterized by comprising:

   The first calculation module is used to obtain the conductor width and spacing of the grid shielding layer, and calculate the signal leakage ratio of the grid shielding layer to the signal transmission amount of the electrical formation;

   The second calculation module is used to obtain the dielectric thickness parameter of the dielectric layer, equate the signal leakage of the grid shielding layer to the increase of dielectric thickness, and calculate the equivalent dielectric thickness based on the leakage ratio and the dielectric thickness parameter;

   The third calculation module obtains the angle between the impedance line and the horizontal side of the grid shielding layer and the dielectric constant of the dielectric layer, and calculates the equivalent dielectric constant based on the time equivalence principle;

   The fourth calculation module is used to obtain the line width and copper thickness of the impedance line, and calculate the line impedance by combining the equivalent dielectric thickness, equivalent dielectric constant and the classic characteristic impedance calculation formula.
8. The line impedance calculation system of the mesh shielding structure according to claim 7, characterized in that the fourth calculation module calculates the line impedance of the mesh shielding structure based on the following formula:

   

   Where _Z1 represents the line impedance, _εr represents the dielectric constant of the dielectric layer, a and b represent the conductor width and spacing of the mesh shielding layer, respectively, θ represents the angle between the impedance line and the horizontal side of the mesh shielding layer, and w and t represent the line width and copper thickness of the impedance line, respectively.
9. An electronic device, characterized in that it includes a processor and a memory, wherein a computer program is stored in the memory, and the processor is used to execute the steps of the method according to claim 1 by calling the computer program stored in the memory.
10. A computer-readable storage medium for storing a computer program for calculating line impedance of a mesh shielding structure, wherein the computer program executes the steps of the method according to claim 1 when running on a computer.

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