A method for obtaining parameters of a printed circuit board substrate

Abstract

The present invention provides a method for obtaining parameters of a printed circuit board material, comprising the following steps: obtaining parameter information of a stripline on the printed circuit board; obtaining physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program; calculating and obtaining required parameters of the printed circuit board material based on the parameter information and the physical parameters. The present invention extracts physical parameters of the stripline based on the physical essence of the stripline on the printed circuit board, and can obtain the material parameters of each frequency point of the stripline without the need for fitting or assuming a model. Moreover, the operation of the present invention is simple and direct, and the accuracy of obtaining the parameters of the printed circuit board material is high.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, especially the technical field of printed circuit boards, and specifically provides a method for obtaining parameters of printed circuit board materials. Background Art

[0002] A PCB (Printed Circuit Board) is an important electronic component, a support for electronic components, a carrier for the electrical interconnection of electronic components, and an important part of circuit design. For high-speed PCB design, it is necessary to perform performance simulation on the PCB during the design and R & D stage. In order to improve the simulation accuracy during the R & D stage, accurate PCB material parameters, relative dielectric constant Dk and loss factor Df, are required.

[0003] Usually, PCB manufacturers will provide the relative dielectric constant Dk and loss factor Df at a certain frequency point for simulation. However, on the one hand, the relative dielectric constant Dk and loss factor Df are frequency-dependent, and on the other hand, the relative dielectric constant Dk and loss factor Df also change with different application scenarios. Therefore, there is a deviation between the relative dielectric constant Dk and loss factor Df provided by PCB manufacturers and the actual parameters. In addition, the methods commonly used in the prior art to extract the relative dielectric constant Dk and loss factor Df of a PCB board are basically by assuming a specific model or fitting parameters. However, the actual situation may not conform to the assumed specific model, and the fitting result may also have low accuracy. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a method for obtaining parameters of printed circuit board materials, which is used to solve the problem that the parameters of printed circuit board materials cannot be accurately and effectively obtained in the prior art.

[0005] To achieve the above purpose and other related purposes, the present invention provides a method for obtaining parameters of printed circuit board materials, including the following steps: obtaining parameter information of a stripline on a printed circuit board; obtaining physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program; calculating and obtaining the required parameters of the printed circuit board material based on the parameter information and the physical parameters.

[0006] In an embodiment of the present invention, the obtaining of the parameter information of the stripline on the printed circuit board includes: obtaining the propagation constant of the stripline on the printed circuit board.

[0007] In an embodiment of the present invention, the obtaining of the parameter information of the stripline on the printed circuit board includes: obtaining the DC resistance of the signal line of the stripline on the printed circuit board; obtaining the size information of the cross-section of the stripline on the printed circuit board.

[0008] In one embodiment of the present invention, obtaining the parameter information of the stripline on the printed circuit board further includes: obtaining the conductivity of the stripline on the printed circuit board based on the DC resistance of the signal line of the stripline on the printed circuit board and the size information of the cross-section of the stripline on the printed circuit board.

[0009] In one embodiment of the present invention, obtaining the physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program includes: configuring the input angular frequency and the transmission medium; constructing a simulated stripline in the preset electromagnetic simulation application program based on the size information of the cross-section of the stripline on the printed circuit board, the conductivity of the stripline on the printed circuit board, the input angular frequency, and the transmission medium; generating the physical parameters of the stripline, namely, the series resistance, the series inductance, and the external inductance, based on the constructed simulated stripline.

[0010] In one embodiment of the present invention, the transmission medium is air.

[0011] In one embodiment of the present invention, calculating the required printed circuit board material parameters based on the parameter information and the physical parameters includes: calculating the first parameter and the second parameter for obtaining the printed circuit board material parameters through a first calculation formula based on the propagation constant of the stripline on the printed circuit board, the series resistance, and the series inductance; calculating the required printed circuit board material parameters based on the first parameter, the second parameter, and the external inductance.

[0012] In one embodiment of the present invention, the first calculation formula is: Where: γ is the propagation constant of the stripline, γ is a complex number, R is the series resistance, L is the series inductance, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, j is the imaginary part, and ω is the input angular frequency.

[0013] In one embodiment of the present invention, the required printed circuit board material parameter is the relative dielectric constant; the calculation formula for the relative dielectric constant is: Where: Dk is the relative dielectric constant, L ext is the external inductance, C is the second parameter, the second parameter is the shunt capacitance, μ0 is the vacuum permeability, and ε0 is the vacuum conductivity.

[0014] In one embodiment of the present invention, the required printed circuit board material parameter is the loss factor; the calculation formula for the loss factor is: Where: Df is the loss factor, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, and ω is the input angular frequency.

[0015] As described above, a method for obtaining the parameters of a printed circuit board substrate of the present invention has the following beneficial effects:

[0016] Based on the physical nature of the stripline on the printed circuit board, the present invention extracts the physical parameters of the stripline. Without the need for fitting or assuming a model, the substrate parameters at each frequency point of the stripline can be obtained. Moreover, the operation of the present invention is simple and direct, and the accuracy of obtaining the printed circuit board substrate parameters is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It shows a schematic diagram of the overall process of the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0018] Figure 2 It shows a schematic diagram of a specific implementation process of the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0019] Figure 3 It shows a curve diagram of the transmission constant of the stripline obtained in the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0020] Figure 4 It shows a curve diagram of the current and voltage of the DC resistance of the stripline obtained in the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0021] Figure 5 It shows an example diagram of the size information of the cross-section of the stripline in the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0022] Figure 6 It shows a curve diagram of the physical parameters of the stripline on the printed circuit board obtained in the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0023] Figure 7 It shows a curve diagram of the relative dielectric constant of the printed circuit board obtained in the method for obtaining the parameters of a printed circuit board substrate in this embodiment;

[0024] Figure 8 It shows a curve diagram of the loss factor of the printed circuit board obtained in the method for obtaining the parameters of a printed circuit board substrate in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following uses specific concrete examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0026] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0027] The purpose of this embodiment is to provide a method for obtaining parameters of a printed circuit board material, which is used to solve the problem that the parameters of the printed circuit board material cannot be accurately and effectively obtained in the prior art.

[0028] The following will elaborate in detail on the principle and implementation manner of the method for obtaining parameters of the printed circuit board material in this embodiment, so that those skilled in the art can understand the method for obtaining parameters of the printed circuit board material in this embodiment without creative labor.

[0029] This embodiment provides a method for obtaining parameters of a printed circuit board material. Figure 1 It is shown as the overall flow schematic diagram of the method for obtaining parameters of the printed circuit board material in this embodiment; as Figure 1 shown, the method for obtaining parameters of the printed circuit board material includes the following steps:

[0030] Step S110, obtaining parameter information of a stripline on a printed circuit board;

[0031] Step S120, obtaining physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program;

[0032] Step S130, calculating and obtaining the required parameters of the printed circuit board material based on the parameter information and the physical parameters.

[0033] The following details the method for obtaining parameters of the printed circuit board material in this embodiment.

[0034] Step S110, obtaining parameter information of a stripline on a printed circuit board.

[0035] In this embodiment, the parameter information of the stripline on the printed circuit board to be obtained includes, but is not limited to, the transmission constant of the stripline, the DC resistance of the signal line of the stripline, the size information of the cross-section of the stripline, and the conductivity of the stripline, etc.

[0036] Among them, there is no specific order between obtaining the transmission constant of the stripline and the DC resistance of the signal line of the stripline. After obtaining the transmission constant of the stripline and the DC resistance of the signal line of the stripline, the size information of the cross-section of the stripline is obtained.

[0037] As Figure 2 shown, it shows a specific implementation example order of the parameter information of the stripline on the printed circuit board obtained in this embodiment.

[0038] In this embodiment, first, step S1 is executed to obtain the transmission constant of the stripline on the printed circuit board;

[0039] Then, step S2 is executed to obtain the DC resistance of the signal line of the stripline on the printed circuit board;

[0040] Next, step S3 is executed to obtain the size information of the cross-section of the stripline on the printed circuit board;

[0041] Then, step S4 is executed to obtain the conductivity of the stripline on the printed circuit board based on the DC resistance of the signal line of the stripline on the printed circuit board and the size information of the cross-section of the stripline on the printed circuit board;

[0042] Next, step S5 is executed to construct a simulated stripline in a preset electromagnetic simulation application program, and generate the physical parameters of the stripline, i.e., series resistance, series inductance, and external inductance, based on the constructed simulated stripline;

[0043] Finally, step S6 is executed to calculate and obtain the required printed circuit board material parameters based on the parameter information and the physical parameters.

[0044] In this embodiment, after extracting the parameter information such as the transmission constant, DC resistance, and size information of the cross-section of the stripline based on the physical nature of the stripline on the printed circuit board, the physical parameters such as the series resistance, series inductance, and external inductance of the stripline are obtained.

[0045] Specifically, in this embodiment, the method for extracting the transmission constant of the stripline based on the physical nature of the stripline on the printed circuit board adopts but is not limited to the TRL, delta-L method, etc. In this embodiment, the delta-L method can be used to extract the transmission constant of the stripline. Among them, the delta-L method for extracting the transmission constant of the stripline is an existing loss test method with simple operation, high test accuracy and de-embedding ability. Its test principle is to design two striplines with different lengths. After obtaining the S-parameters of the long and short lines, the transmission constant of the stripline to be measured is obtained by the method of matrix eigenvalues. The method for extracting the transmission constant of the stripline based on the delta-L method is well-known to those skilled in the art and will not be elaborated here. Among them, Figure 3 It shows the curve graph of the transmission constant of the stripline obtained in the method for obtaining the printed circuit board material parameters in this embodiment. Among them, Figure 3 The curve graph of the transmission constant shown in it is obtained by taking the stripline with a DC resistance of 45 ohms as an example. The transmission constant of the stripline is in complex form, γ = α + jβ, where α is the attenuation constant, β is the phase constant, and j is the imaginary part. Figure 3 The ordinate corresponding to the direction indicated by the arrow in it is the ordinate of the curve corresponding to the arrow.

[0046] In this embodiment, in obtaining the DC resistance of the signal line of the stripline on the printed circuit board and obtaining the size information of the cross-section of the stripline on the printed circuit board, the DC resistance of the signal line of the stripline is measured according to the resistance measurement device to obtain the DC resistance of the signal line of the stripline on the printed circuit board. Figure 4 It shows the current-voltage curve graph of the DC resistance of the signal line of the stripline in the method for obtaining the printed circuit board material parameters in this embodiment. Among them, Figure 4 The current-voltage curve graph of the DC resistance of the signal line shown in it is obtained by taking the stripline with a DC resistance of 45 ohms and a length of 114 mm as an example. Figure 4 The slope of the curve in it is the DC resistance of the signal line of the stripline. The size information of the cross-section of the stripline is measured according to the size test device to obtain the size information of the cross-section of the stripline on the printed circuit board. For example, the printed circuit board (PCB board) is cut by the size test device, and then the size is measured under the microscope to obtain the size information of the cross-section of the stripline on the printed circuit board. Among them, the size information includes information such as the width and height of the cross-section. Figure 5 It shows an example graph of the size information of the cross-section of the stripline in the method for obtaining the printed circuit board material parameters in this embodiment.

[0047] In this embodiment, the conductivity of the stripline on the printed circuit board is obtained based on the DC resistance of the signal line of the stripline on the printed circuit board and the size information of the cross-section of the stripline on the printed circuit board.

[0048] Specifically, the formula for obtaining the conductivity of the stripline on the printed circuit board is as follows: where R dc is the DC resistance of the signal line of the stripline, σ is the conductivity of the stripline, l is the length of the signal line, and S is the area of the cross-section of the signal line (obtained based on the size information of the cross-section).

[0049] After obtaining parameter information such as the transmission constant, metal conductivity, and size information of the cross-section of the stripline, step S120 is continued.

[0050] Step S120: Obtain the physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program.

[0051] Specifically, in this embodiment, the obtaining of the physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program includes:

[0052] 1) Configure the input angular frequency and the transmission medium; wherein, the input angular frequency is consistent with the frequency used when testing and obtaining the transmission constant of the stripline, and the transmission medium is preferably but not limited to air.

[0053] It should be noted that in this embodiment, since the transmission medium is air and the relative dielectric constant of air is 1, if other transmission media are used, the formula for calculating the external inductance of the stripline needs to be multiplied by the relative dielectric constant corresponding to this transmission medium, that is A is the relative dielectric constant of the transmission medium.

[0054] 2) Based on the size information of the cross-section of the stripline on the printed circuit board, the conductivity of the stripline on the printed circuit board, the input angular frequency, and the transmission medium, construct a simulated stripline in the preset electromagnetic simulation application program.

[0055] Among them, the preset electromagnetic simulation application program includes but is not limited to electromagnetic simulation software such as ADS and HFSS. The process of constructing a simulated stripline in the preset electromagnetic simulation application program is as follows: construct a simulated stripline in the preset electromagnetic simulation application program, wherein the conductivity of the metal of the simulated stripline is the conductivity of the stripline on the printed circuit board obtained in step S110, and the size information of the cross-section of the simulated stripline is the size information of the cross-section of the stripline on the printed circuit board obtained in step S110.

[0056] That is to say, in the preset electromagnetic simulation application program, the conductivity of the stripline on the printed circuit board and the size information of the cross-section obtained in step S110 are applied, and air is used as the transmission medium to simulate the stripline based on the set frequency, and the RLGC file of the simulation structure is obtained, that is, the physical parameters of the simulated stripline are obtained. Among them, the RLGC file characterizes the stripline through the RLGC matrix.

[0057] 3) Generate the physical parameters of the stripline, namely series resistance, series inductance, and external inductance, based on the constructed simulated stripline.

[0058] Specifically, in this embodiment, the series resistance of the stripline in the printed circuit board is the series resistance generated in the above-mentioned preset electromagnetic simulation application program, and the series inductance of the stripline in the printed circuit board is the series inductance generated in the above-mentioned preset electromagnetic simulation application program. The external inductance of the stripline in the printed circuit board is the external inductance generated in the above-mentioned preset electromagnetic simulation application program.

[0059] Among them, the external inductance of the stripline in the printed circuit board is calculated based on the simulated capacitance C of the physical parameters of the stripline in the above-mentioned preset electromagnetic simulation application program: Among them, L ext is the external inductance, C is the simulated capacitance, μ0 is the magnetic permeability of vacuum, and ε0 is the conductivity of vacuum. It should be noted that in this embodiment, since air is used as the transmission medium and the relative dielectric constant of air is 1, if other transmission media are used, the above formula needs to be multiplied by the relative dielectric constant corresponding to the transmission medium, that is A is the relative dielectric constant of the transmission medium.

[0060] Figure 6 It shows the curve graph of the physical parameters of the stripline on the printed circuit board obtained in the method for obtaining the printed circuit board sheet parameters in this embodiment. Specifically, it is the curve graph of the three physical parameters of the series resistance R, series inductance L, and external inductance Lext of the stripline in this embodiment obtained in the ADS electromagnetic simulation application program. Among them, Figure 6 the ordinate corresponding to the direction pointed by the arrow in is the ordinate of the curve corresponding to the arrow.

[0061] Step S130, calculate the required printed circuit board sheet parameters based on the parameter information and the physical parameters.

[0062] Specifically, in this embodiment, the calculating the required printed circuit board sheet parameters based on the parameter information and the physical parameters includes:

[0063] 1) Calculate the first parameter and the second parameter of the printed circuit board sheet parameters through the first calculation formula based on the transmission constant, the series resistance, and the series inductance of the stripline on the printed circuit board;

[0064] 2) Calculate the required printed circuit board (PCB) material parameters based on the first parameter, the second parameter, and an external inductor.

[0065] Wherein, in this embodiment, the first calculation formula is: Where: γ is the propagation constant of the microstrip line, γ is a complex number, R is the series resistance, L is the series inductance, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, j is the imaginary part, ω is the input angular frequency. Here, the input angular frequency ω is consistent with the frequency used when measuring the propagation constant of the microstrip line.

[0066] The first calculation formula Due to All parameters in are known. According to the corresponding calculation of the imaginary part and the real part in complex numbers, the corresponding shunt conductance G and shunt capacitance C in G + jωC can be obtained.

[0067] The method for calculating the required PCB material parameters based on the first parameter, the second parameter, and an external inductor is as follows:

[0068] When the required PCB material parameter is the relative dielectric constant Dk, the calculation formula for the relative dielectric constant is: Where: Dk is the relative dielectric constant, L ext is the external inductor, C is the second parameter, the second parameter is the shunt capacitance, μ0 is the permeability of free space, and ε0 is the permittivity of free space. Figure 7 Shows the curve graph of the relative dielectric constant of the PCB obtained in the method for obtaining the PCB material parameters in this embodiment.

[0069] When the required PCB material parameter is the loss factor Df, the calculation formula for the loss factor is: Where: Df is the loss factor, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, and ω is the input angular frequency. Figure 8 Shows the curve graph of the loss factor of the PCB obtained in the method for obtaining the PCB material parameters in this embodiment.

[0070] Therefore, the method for obtaining the PCB material parameters in this embodiment utilizes the physical nature of the microstrip line to obtain the relative dielectric constant Dk and the loss factor Df of the PCB material parameters. The obtaining method is simple and effective, does not require fitting or assuming a model, and can obtain the relative dielectric constant Dk and the loss factor Df at each frequency point of the microstrip line in the PCB.

[0071] In summary, the present invention extracts the physical parameters of the stripline based on the physical essence of the stripline on the printed circuit board. Without the need for fitting or assuming a model, the board parameters at each frequency point of the stripline can be obtained. Moreover, the operation of the present invention is simple and direct, and the accuracy of obtaining the printed circuit board parameters is high. Therefore, the present invention effectively overcomes various drawbacks in the prior art and has high industrial utilization value.

[0072] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for obtaining parameters of a printed circuit board substrate, characterized in that: Including the following steps: Obtain the parameter information of the stripline on the printed circuit board; Obtain the physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program; Calculate the required printed circuit board material parameters based on the parameter information and the physical parameters, wherein, the parameter information includes the propagation constant of the stripline on the printed circuit board, and the physical parameters include series resistance, series inductance and external inductance.

2. The method for obtaining the parameters of a printed circuit board sheet according to claim 1, characterized in that: The obtaining of the parameter information of the stripline on the printed circuit board further includes: Obtain the DC resistance of the signal line of the stripline on the printed circuit board; Obtain the dimension information of the cross-section of the stripline on the printed circuit board.

3. The method for obtaining the parameters of a printed circuit board sheet according to claim 2, characterized in that: The obtaining of the parameter information of the stripline on the printed circuit board further includes: Obtain the conductivity of the stripline on the printed circuit board based on the DC resistance of the signal line of the stripline on the printed circuit board and the dimension information of the cross-section of the stripline on the printed circuit board.

4. The method for obtaining the parameters of the printed circuit board sheet according to claim 3, characterized in that: The obtaining of the physical parameters of the stripline on the printed circuit board based on the parameter information of the stripline on the printed circuit board and a preset electromagnetic simulation application program includes: Configure the input angular frequency and the transmission medium; Construct a simulated stripline in a preset electromagnetic simulation application program based on the dimension information of the cross-section of the stripline on the printed circuit board, the conductivity of the stripline on the printed circuit board, the input angular frequency and the transmission medium; Generate the physical parameters of the stripline based on the constructed simulated stripline: series resistance, series inductance and external inductance.

5. The method for obtaining the parameters of a printed circuit board sheet according to claim 4, wherein: The transmission medium is air.

6. The method for obtaining the parameters of a printed circuit board sheet according to claim 4, characterized in that: The calculating of the required printed circuit board material parameters based on the parameter information and the physical parameters includes: Calculate the first parameter and the second parameter of the printed circuit board material parameters through a first calculation formula based on the propagation constant of the stripline on the printed circuit board, the series resistance and the series inductance; Calculate the required printed circuit board material parameters based on the first parameter, the second parameter and the external inductance.

7. The method for obtaining the parameters of a printed circuit board sheet according to claim 6, characterized in that: The first calculation formula is: where: γ is the propagation constant of the stripline, γ is a complex number, R is the series resistance, L is the series inductance, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, j is the imaginary part, and ω is the input angular frequency.

8. The method for obtaining the parameters of a printed circuit board sheet according to claim 6 or 7, characterized in that: The required printed circuit board material parameter is the relative permittivity; the calculation formula of the relative permittivity is: where: Dk is the relative permittivity, L ext is the external inductance, C is the second parameter, the second parameter being the parallel capacitance, μ0 is the permeability of free space, and ε0 is the permittivity of free space.

9. The method for obtaining the parameters of a printed circuit board sheet according to claim 6 or 7, characterized in that: The required printed circuit board material parameter is the loss factor; the calculation formula of the loss factor is: where: Df is the loss factor, G is the first parameter, the first parameter is the shunt conductance, C is the second parameter, the second parameter is the shunt capacitance, and ω is the input angular frequency.

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