Ten most effective design rules that electronIC design engineers should keep in mind and practICe when using design software for PCB layout design and commercial PCB manufacturing. Engineers do not need to implement these rules in order according to time or relative importance, but only need to follow them to greatly changePCB product design.
Rule 1: Select the correct grid set and always use the grid spacing that matches most components. Although multi grid seems to be effective, if engineers can think more in the early stage of PCB layout design, they can avoid the difficulties in spacing and maximize the application of PCB. Since many equipment have a variety of packaging sizes, engineers should use products that are most conducive to their own design. In addition, polygons are very important for copper plating on circuit boards. When multi grid circuit boards are copper plated on polygons, polygon filling deviation usually occurs. Although it is not based on a single grid standard, it can provide a longer life than the required circuit board.
Rule 2: Keep the path shortest and direct This sounds SIMple and common, but it should be kept in mind at every stage, even if it means changing the board layout to optimize the wiring length. This is especially applicable to analog and high-speed digital circuits, where system performance is always partially limited by impedance and parasitic effects.
Rule 3: Use the power layer as much as possible to manage the distribution of power and ground wires. For most pcb board design software, the copper coating on the power layer is a faster and simpler choice. By connecting a large number of wires together, the current with the highest efficiency and the lowest impedance or voltage drop can be guaranteed, and enough grounding loops can be provided. If possible, multiple power lines can also be run in the same area of the circuit board to confirm whether the ground plane covers most layers of the printed circuit board, which is conducive to the interaction between running lines on adjacent layers.
Rule 4: Use the required test points to group the relevant components. For example, the discrete components required by OpAmp operational amplifiers are placed close to the components so that the bypass capacitors and resistors can cooperate with each other, which helps optimize the wiring length mentioned in Rule 2, and makes testing and fault detection easier.
Rule 5: Repeat the required circuit board on another larger circuit board for multiple times to arrange the printed circuit board. Selecting the most appropriate size for the equipment used by the manufacturer will help reduce the prototype design and manufacturing costs. First, lay out the PCB on the panel, contact the Circuit board manufacturer to obtain the preferred size of each panel, then modify your design specifications, and try to repeat your design multiple times within these panel sizes.
Rule 6: Integrate component values As a designer, you will select discrete components with high or low component values but the same performance. The bill of materials can be simplified and the cost can be reduced by integrating within a SMAller range of standard values. If you have a series of PCBs based on the value of preferred devices, it will be more beneficial to make correct inventory management decisions in the long run.
Rule 7: Perform as many design rule checks as possible Although it only takes a short time to run the digital rights control function on the printed PCB software, in a more complex design environment, as long as you always perform the check during the design process, you can save a lot of time, which is a good habit worth keeping. Every routing decision is critical. You can get the most important routing hints at any time by executing DRC.
Rule 8: Flexible use of screen printing Screen printing can be used to MARK various useful information for future use by circuit board manufacturers, service or test engineers, installers or equipment commissioning personnel. Not only clear function and test point labels are marked, but also the directions of components and connectors are marked as far as possible. Even if these notes are printed on the lower surface of the components used in the circuit board (after the circuit board is assembLED), full application of screen printing technology on the upper and lower surfaces of the circuit board can reduce repetitive work and simplify the production process.
Rule 9: When decoupling capacitors are required, do not try to optimize the design of capacitors by avoiding decoupling of power lines and according to the limits in the component data book. Capacitors are cheap and durable. You can spend as much time as possible assembling capacitors. At the same time, follow Rule 6 and use the standard value range to keep the inventory clean.
Rule 10: Generate PCB manufacturing parameters and verify them before submitting them for production Although most PCB manufacturers are willing to download and verify them for you directly, you'd better output Gerber files first, and then check them with a free viewer to avoid misunderstanding. Through personal verification, you will even find some careless mistakes, thus avoiding the loss caused by completing production according to the wrong parameters.
As circuit designs are more and more widely shared, internal teams increasingly rely on reference designs. Basic rules similar to the above will still be a feature of pcb Board Design, which we believe is very important for pcb board design. By clarifying these basic rules, developers can be very flexible to increase the value of their products and get the maximum benefit from the circuit boards they manufacture. Even novice circuit board designers can speed up the learning process and enhance self-confidence by remembering these basic rules.