PCB design is a very important part of electronic product design, and it is an important carrier of electronic products. A good PCB should not only look good, but also meet the requirements of high cost performance, good electrical performance, high stability and reliability, easy production and maintenance, and easy certification. Some technical experts believe that as an excellent PCB engineer, you should have the following knowledge structure:
1. Be familiar with at least one mainstream EDA tool in the industry
There are many PCB design software, and the main ones currently used in the market include the following four: Cadence Allegro, Mentor
EE, Mentor Pads, Altium Designer, Protel, etc., among which Cadence Allegro has the highest market share.
Allegro has many advantages, such as friendly software operation interface, fast response speed, high operation efficiency, rich secondary development functions, perfect rule manager functions, powerful high-speed design exclusive functions, etc. It has good support for large projects, and will not significantly reduce the response speed due to the increase in design scale. There is basically no pressure to use Allegro to design projects with tens of thousands of pins, so it is very suitable for the communications industry, commercial servers, industrial control, and military fields.
2. Familiar with devices, understand circuit schematics, and recognize key signals
Common electronic components: resistors, capacitors, inductors, transformers, diodes, transistors, field effect transistors, optocouplers (OC), sensors, crystal oscillators, relays, buzzers, rectifier bridges, filters, switches, fuses, etc.
Key signals include: power supply, analog signals, high-speed signals, clock signals, differential signals, synchronization signals, etc.
3. Familiar with the processes and processes of several common boards and circuit board factories
Common boards: cardboard, semi-fiberglass board, FR-4 fiberglass board, aluminum substrate, etc.
4. Familiar with the assembly process and process of patch plug-ins
Mainly understand surface mount technology (SMT), through-hole plug-in technology (THT), etc.
5. Be familiar with welding test
Solderability test is generally used to make a qualitative and quantitative evaluation of the solderability of components, printed circuit boards, solders and fluxes. In the assembly welding process of electronic products, the welding quality directly affects the quality of the whole machine. Therefore, in order to improve the welding quality, in addition to strictly controlling the process parameters, it is also necessary to conduct scientific solderability tests on printed circuit boards and electronic components.
6. Have a certain understanding of SI/PI knowledge
With the increase in the output switching speed of integrated circuits and the increase in the density of PCB boards, signal integrity (SI) has become one of the issues that must be concerned about in high-speed digital PCB design. Factors such as the parameters of components and PCB boards, the layout of components on PCB boards, and the wiring of high-speed signals will cause signal integrity problems, resulting in unstable system operation or even no operation at all. How to fully consider the factors of signal integrity in the design process of PCB boards and take effective control measures has become a hot topic in today’s PCB design industry.
Under the development trend of high power consumption, high density, high speed, high current and low voltage in electronic systems, the power integrity (PI) problem in the field of high-speed PCB design has also become increasingly serious.
As an excellent PCB design engineer, of course, you need to have a certain understanding of SI/PI knowledge to guide the optimization of PCB design, improve power channel design, optimize decoupling capacitor design, etc.
7. Have a deep understanding of the EMC/EMI knowledge of the designed product PB
As we all know, the design of PCB should comprehensively consider multiple factors such as function realization, cost, production process, EMC, and aesthetics.
As the frequency of electronic signals and processors of electronic equipment continues to increase, the electronic system has become a complex device containing multiple components and many subsystems. High density and high speed will increase the radiation of the system, while low voltage and high sensitivity will reduce the anti-interference of the system. Therefore, electromagnetic interference (EMI) is a real threat to the safety, reliability and stability of electronic equipment. When we design electronic products, the design of PCB boards is crucial to solving EMI problems.
