Ten Golden Rules: Best Practices for Optimizing PCB Design

Despite the increasing integration of semiconductors and the availability of off-the-shelf systems on chips (SoCs) for many applications, as well as the growing accessibility of powerful, ready-to-use development boards, many use cases for electronic products still require custom PCBs. Even a standard PCB can play a critical role in one-off development projects.

The PCB serves as the physical platform for design and is the most flexible component for designing electronic systems with raw components. This article will introduce several golden rules for PCB design, which have largely remained unchanged since the commercial birth of PCB design 25 years ago and are widely applicable to various PCB design projects. These rules provide significant guidance for both young electronic design engineers and more established circuit board manufacturers. Below, we outline the ten most effective design rules that electronic design engineers should remember and implement when using design software for PCB layout and commercial manufacturing. Engineers do not need to follow these rules in order of time or relative importance; simply adhering to all of them can greatly enhance product design.

Rule 1: Choose the Right Grid.

Set and always use a grid spacing that can accommodate the most components. While multiple grids may seem useful, if engineers think more critically during the early stages of PCB layout design, they can avoid problems when setting spacing and maximize circuit board usage. Since many devices come in various package sizes, engineers should use products that are most beneficial to their designs. Additionally, polygons are crucial for copper pouring on circuit boards; multi-grid boards may lead to polygon fill discrepancies, which, while not as standardized as single-grid boards, can provide a longer lifespan than required for the circuit board.

Rule 2: Keep Paths Short and Direct.

This may sound simple, but it should be remembered at every stage, even if it means changing the PCB layout to optimize trace length. This is especially true for analog and high-speed digital circuits, where system performance is often limited by impedance and parasitic effects.

Rule 3: Utilize Power Layers to Manage Power and Ground Distribution.

Copper pouring on power layers is often the fastest and simplest choice for most PCB design software. By sharing a large number of traces, it ensures that the current is provided with maximum efficiency and minimum impedance or voltage drop while also providing adequate grounding return paths. If possible, multiple power lines can run in the same area of the circuit board, ensuring that the ground layer covers most of a certain layer of the PCB, which is beneficial for the interaction of traces running on adjacent layers.

Rule 4: Group Related Components with Required Test Points.

For example, place the discrete components required for an OpAmp close to the device so that bypass capacitors and resistors can collaborate with the same ground, helping to optimize the trace length mentioned in Rule 2 and making testing and troubleshooting easier.

Rule 5: Repeat the Required PCB on a Larger Panel for PCB Stacking.

Choosing a size that best fits the manufacturer’s equipment helps reduce prototype design and manufacturing costs. First, layout the PCB on the panel, contact the PCB manufacturer for their preferred panel size specifications, then modify your design specifications and attempt to repeat your design multiple times within those panel sizes.

Rule 6: Consolidate Component Values.

As a designer, you might select components with varying values, but similar performance. By consolidating within a smaller standard value range, you can simplify the bill of materials and potentially lower costs. If you have a range of PCB products based on preferred component values, it will also benefit your long-term inventory management decisions.

Rule 7: Perform Design Rule Checks (DRC) as Often as Possible.

Running the DRC function in PCB software takes only a short time, but in more complex design environments, consistently performing checks during the design process can save a lot of time—this is a good habit to maintain. Every routing decision is critical, and executing DRC can alert you to the most important routing at any time.

Rule 8: Use Silkscreen Flexibly.

Silkscreen can be used to label various useful information for future use by PCB manufacturers, service or testing engineers, installers, or equipment debuggers. Not only should functional and test point labels be clearly indicated, but also the direction of components and connectors should be marked wherever possible, even printing these annotations on the underside of the components used on the PCB (after assembly). Adequately applying silkscreen technology on both sides of the PCB can reduce repetitive work and streamline the production process.

Rule 9: Always Include Decoupling Capacitors.

Do not try to optimize your design by avoiding decoupling power lines and relying on the limits specified in component datasheets. Capacitors are inexpensive and durable, so take as much time as possible to assemble them while following Rule 6, using standard value ranges to keep inventory organized.

Rule 10: Generate PCB Manufacturing Parameters and Verify Before Submission.

While most PCB manufacturers are happy to download and verify directly, it’s best to output Gerber files yourself and check them with a free viewer to ensure they match your expectations, avoiding misunderstandings. By personally verifying, you may even discover some careless errors and thus prevent losses caused by producing according to incorrect parameters.

As circuit design sharing becomes increasingly widespread and internal teams rely more on reference designs, basic rules like the ones above will remain a hallmark of printed circuit board design. We believe these are essential for PCB design.