CN105916303A - PCB and method for producing same - Google Patents

Abstract

The present invention provides a method for generating a PCB board and a PCB board. The method includes: predetermining the signal quality requirements of the signal in the signal line of the PCB board to be generated; determining that the settings in the PCB board to be generated are The line parameter of the signal line in the signal layer of the signal line; Determine the medium parameter of the medium between the signal layer and the reference plane of the PCB board to be generated; Determine the signal parameter of the signal in the signal line; According to the The line parameters, the medium parameters, and the signal parameters, determine the optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirements; generate the PCB to be generated according to the optimized thickness plate. The invention provides a method for generating a PCB board and a PCB board, which can reduce the cost of the PCB board.

Description

A method for generating a PCB board and a PCB board

technical field

The invention relates to the field of electronic technology, in particular to a method for producing a PCB (Printed Circuit Board, printed circuit board) board and a PCB board.

Background technique

With the advent of the era of cloud computing, the development of servers has risen rapidly. In the design of server motherboards, the signal rate is getting higher and higher, and the demand for signal integrity of high-speed signals is also increasing. In the high-speed line design of the PCB board, the long line width and line spacing of the high-speed signal line, the dielectric thickness between the signal line and the reference plane, the electrical performance parameters of the board, and the roughness of the copper foil will all affect the signal loss. How to make reasonable use of these factors to make the signal quality meet the design requirements has become the direction that R&D engineers have been working on to optimize.

In the current design of the PCB board, in order to meet the requirements for signal quality, the board material of the PCB board is usually replaced and a board material with better performance is used to meet the requirements for signal quality.

It can be seen from the above description that in the existing technical solutions, the requirements for signal quality are met by using boards with better performance, which will greatly increase the cost of the PCB board.

Contents of the invention

Embodiments of the present invention provide a method for generating a PCB board and a PCB board, which can reduce the cost of the PCB board.

In the first aspect, the embodiment of the present invention provides a method for generating a PCB, including:

S0: Predetermine the signal quality requirements of the signal in the signal line of the PCB board to be generated;

S1: Determine the line parameters of the signal lines in the signal layer provided with signal lines in the PCB board to be generated;

S2: Determine the medium parameters of the medium between the signal layer and the reference plane of the PCB board to be generated;

S3: Determine signal parameters of the signal in the signal line;

S4: Determine an optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirement according to the line parameter, the medium parameter, and the signal parameter;

S5: Generate the PCB board to be generated according to the optimized thickness.

Further, the signal quality requirements include: eye diagram requirements;

The S4, including:

According to the line parameter, the medium parameter and the signal parameter, simulate the PCB board to be generated, adjust the thickness of the medium between the signal layer and the reference plane, and generate an eye corresponding to each thickness picture;

Based on the generated eye diagram, an optimal thickness that satisfies the requirements of the eye diagram is determined.

Further, the signal parameters include: the signal is a SAS (Serial Attached SCSI) signal;

The requirements of the eye diagram include: the height of the eye diagram is greater than or equal to 75mV, and the width of the eye diagram is greater than or equal to 25pS.

Further, the simulation of the PCB board to be generated includes:

The PCB board to be generated is simulated by using the advanced design system ADS.

Further, the line parameters include: the length of the signal line, and/or, the impedance of the signal line.

Further, the medium parameter includes: a dielectric constant of the medium.

Further, the signal parameter includes: the type of the signal.

Further, said S5 includes:

Import the optimized thickness into the layout design and PCB production of the PCB board to be generated.

Further, said S0 includes:

Determine the signal type of the signal in the signal line of the PCB board to be generated;

Determine the eye diagram requirements that need to be met corresponding to the signal type.

In a second aspect, an embodiment of the present invention provides a PCB board, including:

A PCB board generated according to any one of the methods described in the first aspect.

In the embodiment of the present invention, according to the determined line parameters, medium parameters and signal parameters of the signal lines of the PCB board to be generated, the optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirements is determined, and by adjusting the The thickness of the medium that generates the PCB board is used to improve the signal quality, and the PCB board can meet the signal quality requirements without using a board with better performance, thereby reducing the cost of the PCB board.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flow chart of a method for generating a PCB board provided by an embodiment of the present invention;

Fig. 2 is a flowchart of another method for generating a PCB provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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 It is a part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection of the present invention. scope.

As shown in Figure 1, an embodiment of the present invention provides a method for generating a PCB, which may include the following steps:

S0: Predetermine the signal quality requirements of the signal in the signal line of the PCB board to be generated;

S1: Determine the line parameters of the signal lines in the signal layer provided with signal lines in the PCB board to be generated;

S2: Determine the medium parameters of the medium between the signal layer and the reference plane of the PCB board to be generated;

S3: Determine signal parameters of the signal in the signal line;

S4: Determine an optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirement according to the line parameter, the medium parameter, and the signal parameter;

S5: Generate the PCB board to be generated according to the optimized thickness.

In the embodiment of the present invention, according to the determined line parameters, medium parameters and signal parameters of the signal lines of the PCB board to be generated, the optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirements is determined, and by adjusting the The thickness of the medium that generates the PCB board is used to improve the signal quality, and the PCB board can meet the signal quality requirements without using a board with better performance, thereby reducing the cost of the PCB board.

In an embodiment of the present invention, the signal quality requirements include: eye diagram requirements;

The S4, including:

According to the line parameter, the medium parameter and the signal parameter, simulate the PCB board to be generated, adjust the thickness of the medium between the signal layer and the reference plane, and generate an eye corresponding to each thickness picture;

Based on the generated eye diagram, an optimal thickness that satisfies the requirements of the eye diagram is determined.

In the embodiment of the present invention, the signal quality requirement for the signal is realized through the requirement for the eye diagram. Specifically, it can be realized through requirements on the height and width of the eye diagram. In the embodiment of the present invention, the PCB board to be generated is simulated through the determined line parameters, medium parameters and signal parameters, and the quality of the signal on the signal line is adjusted by adjusting the thickness of the medium between the signal layer and the reference plane. Until the thickness that meets the requirements of the eye diagram is obtained.

Generally speaking, the signal types on the signal line are different, and the requirements of the eye diagram are also different. In an embodiment, the signal parameters include: the signal is a SAS signal;

The requirements of the eye diagram include: the height of the eye diagram is greater than or equal to 75mV, and the width of the eye diagram is greater than or equal to 25pS.

In an embodiment of the present invention, the simulation of the PCB board to be generated includes:

Use ADS to simulate the PCB board to be generated.

In the embodiment of the present invention, the ADS may be Angelen ADS software. Specifically, the active simulation of the PCB board to be generated can be carried out through the Angilen ADS software.

In an embodiment of the present invention, the line parameters include: the length of the signal line, and/or, the impedance of the signal line.

In an embodiment of the present invention, the medium parameter includes: a dielectric constant of the medium. Wherein, the medium may include: materials reinforced with glass cloth, materials without glass cloth reinforcement.

In an embodiment of the present invention, the signal parameter includes: the type of the signal. For example, the signal is a SAS signal.

In an embodiment of the present invention, said S5 includes:

Import the optimized thickness into the layout design and PCB production of the PCB board to be generated.

Specifically, the optimized thickness is used as the thickness of the medium between the signal layer of the PCB to be generated and the reference plane, and is imported into the layout design and PCB production of the PCB to be generated.

The signal in the signal line of the PCB board is generally constant, and in an embodiment of the present invention, the S0 includes:

Determine the signal type of the signal in the signal line of the PCB board to be generated;

Determine the eye diagram requirements that need to be met corresponding to the signal type.

In the embodiment of the present invention, therefore, the signal type of the signal in the signal line can be determined according to the design requirements of the PCB board to be generated, the functions to be completed, etc., and the requirements of the eye diagram can be determined according to the signal type. When multiple signals may be transmitted in the signal line, the requirement of the eye diagram is to meet the requirements of the eye diagram of all types of signals. For example, the requirements of the eye diagram of signal A are: the height of the eye diagram is greater than or equal to 75mV, and the width of the eye diagram is greater than or equal to 25pS; the requirements of the eye diagram of signal B are: the height of the eye diagram is greater than or equal to 80mV, and the eye diagram The width is greater than or equal to 20pS. Then, the requirements of the eye diagram are: the height of the eye diagram is greater than or equal to 80mV, and the width of the eye diagram is greater than or equal to 25pS.

In addition, the requirements of the eye diagram corresponding to each signal can be determined by the spec protocol specification.

As shown in Figure 2, a method for generating a PCB board provided by an embodiment of the present invention, the method includes:

Step 201: Determine the signal type of the signal in the signal line of the PCB board to be generated.

For example, the signal type is a SAS signal type.

Step 202: Determine the eye diagram requirements corresponding to the signal type that need to be met.

For SAS signals, the requirements for the eye diagram can be determined through the spec protocol specification: the height of the eye diagram is greater than or equal to 75mV, and the width of the eye diagram is greater than or equal to 25pS.

Step 203: Determine the line parameters of the signal lines in the signal layer on which the signal lines are arranged in the PCB board to be generated.

Wherein, the line parameter may be the length of the signal line and the impedance of the signal line. For example, the impedance of the signal line is 100ohm. The signal lines here may be differential traces.

Step 204: Determine the medium parameters of the medium between the signal layer and the reference plane of the PCB board to be generated.

The medium parameter may be the dielectric constant of the medium.

Step 205: Determine signal parameters of the signal in the signal line.

The signal parameter may be a signal type, for example, it is determined that the signal is a SAS signal. The signal parameter may also include: the frequency of the signal.

Step 206: According to the line parameters, medium parameters and signal parameters, use ADS to simulate the PCB board to be generated, adjust the thickness of the medium between the signal layer and the reference plane, and generate eye diagrams corresponding to each thickness.

In the embodiment of the present invention, after the line parameters, medium parameters and signal parameters are determined, the eye diagram in the simulation result is adjusted by adjusting the thickness of the medium between the signal layer and the reference plane. When the obtained eye diagram meets the requirements of the eye diagram, it is determined that the thickness is the optimized thickness of the PCB to be generated, that is, the PCB to be generated is manufactured according to the optimized thickness. During the simulation process, under the condition that other conditions of the PCB board to be generated remain unchanged, the thickness of the medium between the signal layer and the reference plane is adjusted. For example: set the thickness of the medium between the signal layer and the reference plane to 4mil, 5mil, and 6mil in sequence. When the thickness is 6mil, the obtained eye diagram meets the requirements of the eye diagram. Specifically, when the thickness is 6mil, the obtained eye diagram The height is 89mV, greater than or equal to 75mV, and the width is 27pS, greater than or equal to 25pS. 6mil can be used as the optimal thickness.

Step 207: According to the generated eye diagram, determine the optimal thickness that meets the requirements of the eye diagram.

Generally speaking, as the thickness of the medium between the signal line and the reference plane increases, the insertion loss value decreases, the height and width of the signal eye diagram at the receiving end also increase, and the signal quality is significantly improved. However, in order to reduce costs, the thickness will not be increased indefinitely, as long as the requirements of the eye diagram are met.

Step 208: Generate the PCB board to be generated according to the optimized thickness.

Specifically, the optimized thickness is imported into the layout design and PCB fabrication of the PCB board to be generated.

For high-speed signals, when designing the PCB board, if the signal line is too long or the crosstalk is large, resulting in serious signal loss and the result of the eye diagram does not meet the requirements, in the embodiment of the present invention, in the stack design, by adjusting The thickness of the medium between the signal layer where the signal line is located and the reference plane is used to reduce signal loss, improve signal quality, and avoid the cost increase caused by the use of high-quality boards.

The comparative simulation results show that with the increase of the medium thickness, the signal loss decreases, the eye height and eye width in the eye diagram also increase obviously, and the signal quality improves obviously. At the same time, the method is simple and easy to use, has strong operability, is suitable for all board designs, and is easy to implement in the design.

An embodiment of the present invention provides a PCB board, including: a PCB board generated according to any one of the methods described in the embodiments of the present invention.

For example, the signal in the signal line of the PCB board is a SAS signal, the impedance of the signal line is 100 ohm, and the thickness of the medium between the signal layer and the reference plane of the PCB board to be generated is 6 mil.

Embodiments of the present invention have at least the following beneficial effects:

1. In the embodiment of the present invention, according to the determined line parameters, medium parameters and signal parameters of the signal lines of the PCB board to be generated, determine the optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirements, and pass By adjusting the thickness of the medium of the PCB board to be generated to improve the signal quality, the PCB board can meet the signal quality requirements without using a board with better performance, and the cost of the PCB board is reduced.

2. When designing the PCB board, if the signal line is too long or the crosstalk is large, resulting in serious signal loss and the result of the eye diagram does not meet the requirements, in the embodiment of the present invention, in the stack design, by adjusting the position of the signal line The thickness of the medium between the signal layer and the reference plane can reduce signal loss, improve signal quality, and avoid the cost increase caused by the use of high-quality plates.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or sequence. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional same elements in the process, method, article or apparatus comprising said element.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned programs can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

Finally, it should be noted that: the above descriptions are only preferred embodiments of the present invention, and are only used to illustrate the technical solutions of the present invention, and are not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for generating a printed circuit board PCB, characterized in that, comprising: S0: predetermine the signal quality requirements of the signal in the signal line of the PCB board to be generated; S1: Determine the line parameters of the signal lines in the signal layer provided with signal lines in the PCB board to be generated; S2: Determine the medium parameters of the medium between the signal layer and the reference plane of the PCB board to be generated; S3: Determine signal parameters of the signal in the signal line; S4: Determine an optimal thickness of the medium between the signal layer and the reference plane that meets the signal quality requirement according to the line parameter, the medium parameter, and the signal parameter; S5: Generate the PCB board to be generated according to the optimized thickness. 2. The method of claim 1, wherein, The signal quality requirements include: eye diagram requirements; The S4, including: According to the line parameter, the medium parameter and the signal parameter, simulate the PCB board to be generated, adjust the thickness of the medium between the signal layer and the reference plane, and generate an eye corresponding to each thickness picture; Based on the generated eye diagram, an optimal thickness that satisfies the requirements of the eye diagram is determined. 3. The method of claim 2, wherein, The signal parameters include: the signal is a SAS signal; The requirements of the eye diagram include: the height of the eye diagram is greater than or equal to 75mV, and the width of the eye diagram is greater than or equal to 25pS. 4. The method of claim 2, wherein, The described PCB board to be generated is simulated, including: The PCB board to be generated is simulated by using the advanced design system ADS. 5. The method of claim 1, wherein, The line parameters include: the length of the signal line, and/or, the impedance of the signal line. 6. The method of claim 1, wherein, The medium parameters include: the dielectric constant of the medium. 7. The method of claim 1, wherein, The signal parameters include: the type of the signal. 8. The method according to claim 1, wherein said S5 includes: Import the optimized thickness into the layout design and PCB production of the PCB board to be generated. 9. The method according to any one of claims 1-8, wherein the S0 includes: Determine the signal type of the signal in the signal line of the PCB board to be generated; Determine the eye diagram requirements that need to be met corresponding to the signal type. 10. A printed circuit board PCB, characterized in that, comprising: The PCB board produced by the method according to any one of claims 1-9.