Electronic Design - 7 good habits of PCB layout engineer

In some people's opinion, the work of PCB layout engineer will be a little boring. Every day, they face thousands of PCB wires, various packages and repeat the work of pulling wires... In fact, it is not as simple as it seems. PCB layout engineer should make trade-offs between various design rules, give consideration to performance, process, cost and other aspects, and pay attention to the reasonable and orderly layout of PCB. As an excellent PCB layout engineer, good working habits will make your design more reasonable, performance better and production easier. Here are 7 good habits of PCB layout engineers. Let's see how many you have!

1. Learn to set rules

In fact, not only advanced PCB design software needs to set wiring rules, but also some simple and easy-to-use PCB tools can set rules. After all, the human brain is not a machine, so it is inevitable that there will be negligence and mistakes. So set some easily ignored problems into the rules and let the computer help us check to avoid making some low-level mistakes as far as possible. In addition, perfect rule setting can better standardize the later work. The more complex the size of PCB, the more important the rule setting is.

2. Perform DRC as much as possible

Although it takes only a short time to run the DRC function on PCB layout software, in a more complex design environment, you can save a lot of time as long as you always perform checks during the design process, which is a good habit worth keeping. Every routing decision is critical, and you can be prompted for the most important routing at any time by executing DRC.

3. Draw the schematic diagram

Many engineers think that PCB layout is more important. The schematic diagram is to generate a net list for PCB inspection. In fact, the function of schematic diagram will be greater in the subsequent circuit debugging process. Whether it is to find problems or communicate with colleagues, or the schematic diagram is more intuitive and convenient. In addition, form the habit of marking in the schematic diagram, and mark the problems that should be noticed when each part of the circuit is in PCB layout on the schematic diagram, which is a good reminder for yourself or others. The hierarchical schematic diagram divides the circuits of different modules with different functions into different pages, so that the workload can be significantly reduced whether it is reading the diagram or reuse in the future.

4. Optimize PCB layout

After drawing the schematic diagram and importing the net list into the PCB, the anxious engineer can't wait to put the devices in place and start pulling wires. In fact, a good PCB layout can make the cable work behind you easier and make your PCB layout job better. Each PCB board will have a signal path, and the PCB layout should follow this signal path as much as possible, so that the signal can be transmitted smoothly on the PCB board. People don't like to go through the maze, and the signal is the same. If the schematic diagram is designed according to the module, the PCB layout is also OK. The PCB can be divided into several areas according to different functional modules. Analog and digital are separated, power signals are separated, heating devices and susceptible devices are separated, larger devices should not be too close to the board edge, pay attention to the shielding of RF signals, etc... taking one more minute to optimize the PCB layout can save more time when pulling wires.

5. Think more about others

When designing PCB layout, consider the needs of end users as much as possible. For example, if you are designing a development PCB, you should consider placing more silk screen information when designing the PCB layout, so that it will be more convenient to use it without looking up the schematic diagram back and forth or looking for the support of designers. If the design is a mass-produced product, more consideration should be given to the problems encountered in the production line. The same type of devices should have the same direction as far as possible, whether the device spacing is appropriate, the process edge width of PCB board, etc. The earlier these problems are considered, the less they will affect the later design, and can also reduce the workload of later support and the number of board changes. It seems that the time spent on design has increased, but in fact, it has reduced its subsequent workload. When the space signal of PCB board allows, try to place more test points to improve the testability of PCB board, so as to save more time in the subsequent debugging stage and provide more ideas for finding problems.

6. Communicate and confirm with customers repeatedly

As an excellent PCB layout engineer, we should learn to communicate effectively with customers. For some important issues in PCB layout, it is best to repeatedly communicate with customers for confirmation, such as packaging confirmation. In particular, the positions of positive and negative electrodes, triodes and structural connectors will directly affect the installation and positioning of boards in the later stage.

7. Details determine success or failure

PCB layout design is a meticulous work, which requires care and patience. Novice designers often make mistakes in details. Wrong device pins, wrong device packaging, reversed pin sequence, etc. some can be solved by flying wires, and some may directly turn a PCB into waste. When painting the package, check it again. Before throwing the board, print out the package and compare it with the actual device. It's not obsessive-compulsive disorder to check it again. It's just to avoid these easy low-level mistakes as far as possible. Otherwise, no matter how good-looking the PCB is, it is far from excellent because it is full of flying wires. Good PCB layout working habits benefit you a lot.