Ten Golden Rules of PCB Design

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Rule One: Choose the right grids, set and always use the grid spacing that matches the most components. Although multi-grid seems to be effective, if engineers can think more about beginning of the PCB layout design, they can avoid problems when setting up the interval and make the most of the PCB. Since many devices are available in a variety of package dimensions, engineers should use the products that are best for their design. In addition, polygons are critical for PCB copper coatings. Multi-grid PCB typically produce polygon fill deviations when performing polygon copper coating. Although it is not as standard as a single grid, it provides more than the required PCB life.



Rule Two: Keep the route shortest and most direct. This sounds simple and common, even if it means changing the PCB layout to optimize the wiring length, but it should be kept in mind at every stage. This rule is also suitable for analog and high-speed digital circuits where system performance is always partially limited by impedance and parasitic effects.



Rule Three: Use the power plane to manage the distribution of power line and ground wire as much as possible. Adding copper to the power plane is a faster and simpler option for most PCB design software. By connecting a large number of wires in a common connection, the highest efficiency and minimum impedance or voltage drop current is guaranteed while providing a sufficient ground return route. If possible, run multiple power circuits in the same area of the PCB to verify that the ground plane cover most of the layers of a certain layer of the PCB, which facilitates the interaction between the circuits running on adjacent layers.



Rule Four: Group related components with the required test points. For example, placing the discrete components required for the OP Amp close to the device so that the bypass capacitors and resistors can collaborate with them, helping to optimize the routing lengths mentioned in Rule 2, while also making test and fault detection easier. 



Rule Five: Make the required PCB panels. Choosing the size that best suits the equipment used by the manufacturer helps to reduce prototyping and manufacturing costs. First make the PCB layout on the panel, contact the PCB manufacturer to get the preferred size specifications for each of their panels, then modify your design specifications and try to repeat your design multiple times within these panel sizes. 



Rule Six: Integrate component value. As a designer, you will choose discrete components with high or low component values but the same performance. By integrating within a small range of standard values, bills of materials can be simplified and costs can be reduced. In the long term, if you have a range of PCB products based on your preferred device values, its also good for you to make the right inventory management decisions.



Rule Seven: Perform design rule checks as much as possible. Although running DRC functions on PCB software takes only a short amount of time, in a more complex design environment, you can save a lot of time by performing checks during the design process. This is a good habit to keep. Every cabling decision is critical, and you can always remind you of the most important cabling by performing a DRC.



Rule Eight: Flexible use of screen printing. Screen printing can be used to label a variety of useful information for future use by PCB manufacturers, service or test engineers, installers or equipment commissioners. Not only the clear function and test point labels, but also the direction of the components and connectors should be marked as much as possible, even after the PCB is assembled, to print these notes on the surface under the components used on the PCB. Full application of screen printing technology on the lower surface of the PCB reduces duplication of effort and streamlines the production process.



Rule Nine: Decoupling capacitors must be selected. Do not attempt to optimize your design by avoiding decoupling the power cord and depending on the limits in the component data sheet. Capacitors are cheap and rugged, so you can spend more time assembling capacitors while following Rule 6, using standard values to keep your stocks tidy.



Rule Ten: The resulting PCB manufacturing parameters should be verified prior to submission to production. Although most PCB manufacturers are glad to download and verify it for you, it is best to export the Gerber file yourself and use the free viewer to check if the file is as expected to avoid misunderstandings. By personally verifying, you will find some negligent mistakes, and thus avoid losing production by following the wrong parameters.