High Speed PCB Design Specifications

High-speed PCB design is a necessary stage in the development of my country's electronics industry, mainly to ensure the stability and compatibility of electronic products. High-speed PCB design is a very complex and highly professional job, which requires relatively high requirements for the professionalism and work experience of designers.

In addition, in the process of high-speed PCB design, there are many rules required, but in these rules, conflicts and contradictions often occur, resulting in the failure of high-speed PCB design work to proceed smoothly. Therefore, in this case, designers need to make corresponding judgments based on their own high-speed PCB design experience and the actual situation of the design, and carry out effective solutions to ensure the smooth development of high-speed PCB design work and ensure that electronic The stability and security of the digital system also play a very important role and significance in the realization of its functions.

1. Analysis of high-speed PCB design rules

In order to improve the quality of high-speed PCB design, it is necessary to have a certain understanding of design rules, such as: layout, wiring, etc., so as to ensure the pertinence in high-speed PCB design. The specific content is as follows:

1.1 Layout

In the process of high-speed PCB layout, it is necessary to start from the overall point of view and plan according to the principle of whole to detail to ensure the accuracy of high-speed PCB design. Then, in the process of high-speed PCB layout design, the specific content is as follows:

(1) In the process of high-speed PCB layout design, it is necessary to misalign the connection between high-frequency components as much as possible to reduce their distribution parameters and mutual electromagnetic interference. At the same time, for components that are susceptible to interference, they must not be too close to each other, and a certain distance is kept between input and output components, which can reduce interference to components.

(2) If the components are heavy, they should be fixed by brackets, and then the corresponding welding work should be carried out. However, for those large and heavy components that generate heat, they must not be installed on the printed board, but should be installed on the chassis bottom plate of the whole machine, and the heat dissipation problem should be considered, so as to ensure the rationality of the layout.

(3) For the components near the circuit board, a certain distance should be kept from the circuit board, which should be controlled within 2mm under normal circumstances. At the same time, the best shape of the circuit board should be a rectangle. In addition, when the size of the circuit board is 200mm×150mm, the mechanical strength of the circuit board must be considered to ensure the rationality of the high-speed PCB design.

1.2 Wiring

(1) The wires used at the input and output terminals must try to avoid the phenomenon of adjacent parallels. It is best to use the ground wire between the wires, so as to ensure the rationality of the wiring.

(2) The minimum width of the printed guide is mainly determined by the adhesion strength between the wire and the substrate and the current value flowing between them. At the same time, in the process of high-speed PCB layout design, if the thickness of the copper foil is 0.05mm, the width is 1mm~15mm, and the passing current is less than 2A, the temperature will not be higher than 3°C. In addition, for integrated current, especially for digital circuits, the wire width of 0.02mm~0.3mm is generally selected to ensure the stability of the system operation. However, in the process of high-speed PCB design, there are errors, so the error must be controlled. Generally, it should be controlled between 5mm and 8mm.

2.High-speed PCB design content analysis

In the process of high-speed PCB design, there are many contents involved, such as: preliminary preparation work, layout design, wiring design, etc. Only by understanding each link in detail and strengthening the design, can high-speed PCB be guaranteed. Regarding the quality of the design, the following is a brief introduction of some experience in design for these aspects:

2.1 Preparations

The preparation work in the early stage of high-speed PCB design directly affects the development of design work and the speed of design work. Therefore, in the process of high-speed PCB design, detailed preparations must be made. According to the design work experience of the designer, it can be expanded from the following aspects:

(1) Make a detailed circuit diagram. The accuracy and comprehensiveness of the circuit diagram directly affect the quality of high-speed PCB design, although the computer can be used to make corresponding adjustments and changes to high-speed PCB design. However, in the process of affecting the degree, if a component is changed, the overall layout degree will change accordingly, which will affect the quality and process of high-speed PCB design. Therefore, according to the relevant experience of the designer, the corresponding circuit diagram must be prepared, so as to ensure the accuracy of high-speed PCB design and the quality of the design.

(2) Encapsulation of circuit components. Circuit component encapsulation is an important basis for high-speed PCB design, but in the process of designing encapsulation, it must be based on the physical object and a certain amount of space must be reserved. In the process of space reservation, it should be calculated according to the corresponding data and information, and random estimation cannot occur. This is mainly to avoid the stability of high-speed PCB design products. If the situation is relatively serious, there will be scrapped Phenomenon.

(3) The actual size and size of the product exterior. The actual size and size of the exterior directly affects the size of the high-speed PCB. Therefore, in the process of high-speed PCB design, it is necessary to combine high-speed PCB design and external design with each other. At the same time, in the design process, if the adjustable components on the external panel, connectors and switching components are installed on the high-speed PCB, then the high-speed PCB and the external should be comprehensively considered to ensure good coordination and design together, so as to ensure The quality of high-speed PCB design.

2.2 Rationality of high-speed PCB size

High-speed PCB size is a very important item in the design. In the process of high-speed PCB design, if the size of the high-speed PCB is relatively large, the printed lines will be relatively long, so the impedance will increase accordingly, and the anti-noise ability will also decrease accordingly. If the size of the high-speed PCB is relatively small, the heat dissipation performance of the components will be relatively poor, the installation will be relatively difficult, and the interference will be relatively large. Therefore, in the process of high-speed PCB design, the size must be designed according to the actual situation of the circuit, which can further ensure the accuracy of high-speed PCB design.

2.3 Overall layout design of high-speed PCB

Layout design is an overall plan of high-speed PCB design, so in the process of high-speed PCB design, we must pay enough attention to the overall layout design. Then, in the process of specific design, it can be expanded from the following aspects:

(1) In general, electronic circuits are composed of input stages, intermediate stages, and output stages. Therefore, in the process of high-speed PCB design, the overall layout should follow the signal flow, and the circuit unit position should be reasonably laid out, so as to ensure the stability of various signal transmissions. (2) In the process of circuit layout design of each functional unit, it is mainly based on components, and the corresponding layout is carried out around this central point, thereby ensuring the integrity of high-speed PCB design. (3) For the layout design of special components, a relatively suitable position should be set according to its particularity. (4) In the process of high-speed PCB design, if there are some relatively heavy components, the position of the fixed bracket should be designed, and the balance of each part should be paid attention to, which provides relatively convenient conditions for later production. (5) For components with relatively high heat generation performance, the corresponding heat dissipation must be set, or a corresponding heat dissipation method should be adopted to ensure the stability of the components.

2.4 High-speed PCB layout design

(1) Both digital signals and high-frequency analog signals have harmonics. Therefore, in the design process, the printed wire must not be designed with right angles and included angles at the corners, and the design shape of the arc can be used, which can play a role in radiation protection. (2) In the design process, if the area of high-speed PCB copper foil is relatively large, it can be designed in the form of a grid. The main purpose is to avoid deformation.

2.5 Ground Wire Design

Ground wire design is a very important content in high-speed PCB design, which can be developed from the following aspects: (1) Ground wire design is a very important content in high-speed PCB design, and its structure must be detailed Understanding, which mainly includes: system ground, shielding ground, digital ground and analog ground and other aspects. (2) During the design process, try to use a thicker ground wire, which can ensure the stability of the current operation and allow 3 times the current to flow. (3) In the process of ground wire design, each ground wire structure must form a closed loop, which can play the role of healthy noise and effectively reduce the phenomenon of potential difference.

Summarize

To sum up, this article briefly analyzes and elaborates on the relevant content of some rules of high-speed PCB design, and from the rationality of high-speed PCB size, the overall layout design of high-speed PCB, high-speed PCB wiring design, ground wire design, etc. On the one hand, the experience of its design is briefly discussed. Its main purpose is to ensure the quality and progress of high-speed PCB, and provide important support for the development of my country's electronic industry.

The above is the design experience of high-speed PCB introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have software and hardware function development needs for smart electronic products, you can rest assured to entrust them to us. We have rich experience in customized development of electronic products, and can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, Bluetooth IC and module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth wifi development, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.