Do you know how to design the PCB to be better?
Many people think that the work of PCB layout is boring. Every day, thousands of wires are routed to the PCB board, various packages, and the work of pulling wires is repetitive. However, board designers must make trade-offs between various design rules, taking into account performance, cost, process and other aspects, while also paying attention to the PCB board layout is reasonable and neat. It is not as simple as it seems and requires more intelligence. . Developing some good working habits when designing will make your design more reasonable, easier to make and better performance.
(1) Draw design schematics
Many engineers believe that PCB layout is more important. The schematic diagram is to generate a netlist to facilitate PCB inspection. In fact, the schematic diagram will be more useful in the subsequent circuit debugging process. Whether it is to find problems or communicate with colleagues, or schematic diagrams are more intuitive and convenient. In addition, get into the habit of labeling in the schematic diagram, marking the layout of each part of the circuit should be noted in the schematic diagram is a good reminder for yourself or others. Layering the schematic diagrams, dividing the circuit into different pages for different functions and modules, can greatly reduce the workload whether you are looking at the diagram or reusing it later. It is always less risky to use a proven design than to design a new circuit. Every time I see all the circuits on the drawing, a dense device, my head gets bigger.
(2) Reasonable circuit layout
If the more impatient engineers draw the PCB schematic, after importing the netlist into the PCB, you can not wait to put the device and start pulling wires. In fact, a good PCB layout can make your wire pulling easier and make your PCB work better. If the schematic is designed according to the module, then the PCB is the same. Depending on the functional modules, the board can be divided into several areas. Separate analog and digital, separate power signals, separate heat generating devices and susceptible devices, do not put larger devices too close to the edge of the board, pay attention to the shielding of RF signals, etc. .... Spend more money Optimizing the PCB layout time can save more time pulling wires.
(3) Details determine success or failure
PCB design is a meticulous work, all it takes is care and patience. A common mistake made by novice designers just starting out is detail errors. Wrong device pins, wrong device package used, reversed pin order, etc. Some of them can be solved with flying wires, some may turn the board into a scrap board directly. When drawing the package, please double check and compare it with the actual device before printing the package. Take a look. Checking it again is not OCD. It's just to try to avoid these low-level mistakes that are easy to make. Otherwise, even if the design is beautiful and the board is covered with flying lines, it is not good enough to talk about.
(4) Learn to set PCB design rules
In fact, not only advanced PCB design software needs to set the wiring rules, some easy-to-use PCB tools can also set the wiring rules. After all, the human brain is not a machine, there are inevitably oversights and mistakes. So set some easily ignored issues as rules, so that the computer can help us check and try to avoid making some low-level mistakes. In addition, a complete set of rules set can better regulate the follow-up work. As the saying goes, the more complex the scale of the board, the more important the rule setting becomes. Nowadays, many EDA tools have automatic wiring function. If the rules are set up in sufficient detail, let the tool design it for you. Wouldn't it be more pleasant to have a cup of coffee on the side?
(5) Try to create PCB simulation products
Simulation is usually something that PCB design engineers do not want to touch. Some may say, even if I simulate, the actual production PCB will still be different from the simulation results, so do not waste time. I do not have the simulation of the board does not work well? I am very concerned about this idea. No help. Design once or twice without problems, does not mean that there is no problem in the future. Although the simulation result is different from the actual result, the simulation can show the correct trend of change, and we can make our own judgment based on the trend. It may be difficult at the beginning, and it is normal for the simulation model to be confused with the simulation parameters. At first, do it slowly and accumulate slowly, and you will realize the importance of simulation. Determine the location of the problem in advance and solve it in advance to avoid problems before you finish the board. If you do too many simulations, you will get to the root cause of the problem and it will help you a lot to improve your design ability.