阅读说明：本技术 一种pcb设计方法 (PCB design method ) 是由 郭丹萍 于 2019-09-05 设计创作，主要内容包括：本申请公开了一种PCB设计方法,包括将PCB脚本中的被动元件的丝印放置在显示顶层并保存至本地库；判断PCB的板卡的pin密度；当所述板卡的pin密度大于预设阈值时,对artwork的silk/top和silk/bot层面进行丝印的调整；将所述artwork的assembly/top和assembly/bot层面的文字居中摆放,打印成PDF档案,因此被动元件的丝印就不会对PCB的设计造成干扰了,这些被动元件对于芯片和功能的识别等工作影响不大,这样工程师就不需要花费精力删除一些丝印来腾出设计空间了,从而能够简化PCB处理丝印的流程,减少layout工程师的工作量,提高layout工程师的工作效率和正确率。(The application discloses a PCB design method, which comprises the steps of placing silk screen printing of passive elements in a PCB script on a display top layer and storing the silk screen printing of the passive elements in a local library; judging the pin density of the PCB board card; when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork; will the characters of the attribute/top and the attribute/bot aspect of artwork are put in the middle, print into the PDF archives, consequently the silk screen printing of passive component just can not cause the interference to PCB's design, these passive components are little to work influence such as the discernment of chip and function, and the engineer just need not spend energy to delete some silk screens like this and vacate the design space, thereby can simplify the flow that PCB handled the silk screen printing, reduce layout engineer's work load, improve layout engineer's work efficiency and rate of accuracy.)

1. A PCB design method, comprising:

placing the silk screen of the passive element in the PCB script on the top display layer and storing the silk screen of the passive element in a local library;

judging the pin density of the PCB board card;

when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork;

and placing the characters on the assembly/top and assembly/bot layers of the artwork in the middle, and printing the characters into a PDF file.

2. The PCB design method of claim 1, further comprising:

and placing the silk screen of part of active elements in the PCB script on a display top layer and storing the silk screen to a local library.

3. The PCB design method of claim 1, further comprising:

and when the board card density is not greater than the preset threshold value, adding the silk screen of the passive element in the top display layer to a silk/top layer of the artwork.

4. The PCB design method of claim 3, further comprising: and adding a display bottom layer to the silk/bot layer of the artwork.

5. A PCB design method as claimed in any of claims 1-4, wherein the preset threshold is 200 pins/sqin.

6. A PCB design method according to claim 5, wherein the passive element is a resistor and/or a capacitor.

Technical Field

The invention belongs to the technical field of PCBs, and particularly relates to a PCB design method.

Background

With the rapid development of the electronic industry, the density of parts on the PCB card is higher and higher. According to the traditional method, a layout engineer is required to place the screen printing of each part nearby, as shown in fig. 1, fig. 1 is a schematic view of the placement of the parts on the existing PCB board card, and therefore the hardware engineer can conveniently test, install and maintain the parts. However, almost all cards with complex storage have high density, as shown in fig. 2, fig. 2 is a schematic diagram of cards with complex storage in the prior art, and all silk screens cannot be clearly placed on a PCB according to the requirement of the size of the silk screen, at this time, a layout engineer will manually delete some silk screens with small resistors and capacitors which are not important according to the size of the space, which has little influence on the identification of chips and functions, but such a method has the disadvantages of easy deletion and overlarge repeated workload.

Disclosure of Invention

In order to solve the problems, the invention provides a PCB design method which can simplify the flow of PCB screen printing processing, reduce the workload of layout engineers and improve the working efficiency and accuracy of the layout engineers.

The PCB design method provided by the invention comprises the following steps:

placing the silk screen of the passive element in the PCB script on the top display layer and storing the silk screen of the passive element in a local library;

judging the pin density of the PCB board card;

when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork;

and placing the characters on the assembly/top and assembly/bot layers of the artwork in the middle, and printing the characters into a PDF file.

Preferably, in the PCB design method, the method further includes:

and placing the silk screen of part of active elements in the PCB script on a display top layer and storing the silk screen to a local library.

Preferably, in the PCB design method, the method further includes:

and when the board card density is not greater than the preset threshold value, adding the silk screen of the passive element in the top display layer to a silk/top layer of the artwork.

Preferably, in the PCB design method, the method further includes: and adding a display bottom layer to the silk/bot layer of the artwork.

Preferably, in the PCB design method, the preset threshold is 200pins/sq in.

Preferably, in the above PCB design method, the passive element is a resistor and/or a capacitor.

According to the PCB design method provided by the invention, as the silk screen printing of the passive elements in the PCB script is firstly placed on the display top layer and is stored in the local library; then, judging the pin density of the board card of the PCB; when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork; finally, the letters on the assembly/top and assembly/bot layers of the artwork are placed in the middle and printed into PDF files, so that the screen printing of passive elements does not interfere with the design of the PCB, the passive elements have little influence on the work such as chip identification, and thus, engineers do not need to spend efforts to delete some screen printing to vacate a design space, thereby simplifying the flow of PCB screen printing processing, reducing the workload of layout engineers, and improving the work efficiency and accuracy of layout engineers.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of a conventional PCB card showing placement of components;

FIG. 2 is a schematic diagram of a prior art card with complicated storage;

fig. 3 is a schematic diagram of a PCB design method provided in the present application.

Detailed Description

The core of the invention is to provide a PCB design method, which can simplify the flow of PCB screen printing processing, reduce the workload of layout engineers and improve the working efficiency and accuracy of the layout engineers.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An embodiment of a PCB design method provided by the present application is shown in fig. 3, where fig. 3 is a schematic diagram of the PCB design method provided by the present application, and the method includes the following steps:

s1: placing the silk screen of the passive element in the PCB script on the top display layer and storing the silk screen of the passive element in a local library;

specifically, the method may open a print dra document using allogoro software, wherein a PCB, i.e., a Printed Circuit Board, and passive components including, but not limited to, resistors and/or capacitors, are placed on a TOP DISPLAY layer, i.e., a REF DES/DISPLAY _ TOP layer, and then are not Printed out in a subsequent step, and do not interfere with the screen printing of other components (mainly active components), and the reason why the passive components are placed on the TOP DISPLAY layer and are not placed on the TOP screen layer is that: even if the passive elements are not printed out in a silk screen mode, the identification of the types and functions of the chips cannot be influenced, namely, the silk screen printing of the passive elements is irrelevant.

S2: judging the pin density of the PCB board card;

generally, the purpose of judging the pin density is to determine whether all silk screens can be clearly laid into the PCB, and after all, if the pin density is as shown in fig. 2, it cannot be ensured that all silk screens can be clearly displayed to a user, and the disordered silk screens cause difficulty in identifying elements of the user.

S3: when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork;

the artwork is a manufacturing file provided by a PCB design engineer for a PCB factory, silk screen is a bit number identification of an element on the PCB, when the pin density of a board card is too high to put the silk screen of a passive element, the silk screen of the passive element is kept unchanged on the top display layer, and at the moment, the silk screen of the silk/top and silk/bot layers of the artwork is directly adjusted, namely, the silk screens on the two layers are centered or moved integrally, so that the two layers do not overlap.

S4: and placing the characters on the assembly/top and assembly/bot layers of the artwork in the middle, and printing the characters into a PDF file.

It should be noted that the assembly/top is also the top layer of the assembly, the assembly/bot is the bottom layer of the assembly, the characters of the two layers are only displayed and are not printed by silk screen, and the PDF files can be printed and delivered to the PCBA factory after the characters are placed in the middle.

As can be seen from the above description, in the embodiment of the PCB design method provided in the present application, the silk-screen printing of the passive components in the PCB script is firstly placed on the display top layer and stored in the local library; then, judging the pin density of the board card of the PCB; when the pin density of the board card is larger than a preset threshold value, adjusting silk screen printing on a silk/top layer and a silk/bot layer of the artwork; finally, the letters on the assembly/top and assembly/bot layers of the artwork are placed in the middle and printed into PDF files, so that the screen printing of passive elements cannot interfere with the design of the PCB, the passive elements have little influence on the work such as chip identification, and thus, engineers do not need to spend efforts to delete some screen printing to vacate a design space, thereby simplifying the flow of PCB screen printing processing, reducing the workload of layout engineers, and improving the work efficiency and accuracy of the layout engineers.

In a specific embodiment of the PCB design method, the method may further include the steps of: the method includes the steps that screen printing of part of active elements in a PCB script is placed on a display top layer and stored in a local library, and it needs to be explained that the condition is suitable for the condition that the PCB design space is more crowded, namely, even if screen printing of all passive elements is moved away, the PCB design effect is still unclear, and at the moment, screen printing of part of active elements which are relatively not too critical needs to be placed on the display top layer, so that enough space is reserved for screen printing of the critical active elements, and errors caused when an engineer deletes the screen printing in a subsequent process are avoided. This is of course a specific embodiment, that is, this is an alternative, and in practice, in some cases, it is not necessary to move the screen of the active elements, and it is only the screen of the passive elements that is moved to ensure the screen is clear.

In another specific embodiment of the PCB design method, the method may further include the steps of: when the density of the board card is not greater than the preset threshold value, the silk screen of the passive element in the TOP DISPLAY layer is added to the silk/TOP layer of the artwork, namely, the REF DES/DISPLAY _ TOP is added to the silk/TOP layer of the artwork, and therefore all the silk screens are manufactured under the condition that the elements on the board card and the silk screen are not crowded, and the DISPLAY is more comprehensive. In addition, when there are more passive components, the screen printing of a part of the passive components will be automatically transferred to the bottom DISPLAY layer, i.e. REF DES/DISPLAY _ bot, if the top DISPLAY layer is not accommodated, in this case, the method further includes the following steps: the display underlay is added to the silk/bot layer of the artwork, so that no drop is caused, and the silk screen printing of all the elements is ensured to be displayed, which is certainly a choice in some possible cases, and is not required in other cases.

In a preferred embodiment, the preset threshold is 200pins/sq in, which means that when the area per square foot exceeds 200pins, the screen printing of the passive components is kept on the top display layer, and cannot be performed, and when the area per square foot is less than 200pins, the passive components are screen printed, and it should be noted that the density can be derived from the PCB file.

In summary, by using the method, a factory does not print the screen printing of the passive components (or a part of active components are added) on the PCB board, which solves the problem of false deletion or missed deletion caused by manual screen printing deletion from the source of PCB design, improves the working efficiency and accuracy, and adjusts the assembly/top and assembly/bot two layers and outputs the PDF file thereof, thereby facilitating the debug and maintenance of board factories and hardware engineers.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.