COMPONENT DESIGN
Top 5 guidelines for successful PCB design
Designing a PCB involves more than placing components and connecting them according to the circuit schematic, it also requires careful consideration of manufacturing, assembly and long-term performance.
P
oor layout choices can cause signal integrity problems, electromagnetic interference, component conflicts, reduced functionality, or even total board failure. Fixing these issues later in the process is costly in both time and resources. One way to avoid these pitfalls is to adopt a Design for eXcellence (DfX) approach. Rather than focusing solely on circuit functionality, DfX encourages engineers to consider the downstream impact of their choices on fabrication, assembly and testing. The goal is to get the design right the first time, producing a board that meets performance, quality and reliability requirements without repeated redesigns. Following a clear set of PCB layout guidelines helps achieve this outcome.
Component placement Orientation is important: setting similar components in the same direction helps achieve efficient, error-free soldering, particularly in wave soldering applications. Placement also matters, so it is important to avoid positioning components on the solder side where they would interfere with plated- through holes. Finally, organisation can streamline assembly. When possible, group parts by technology, such as all surface- mount or all through-hole components, and consult with your EMS partner to ensure the layout aligns with their production capabilities, preventing unexpected challenges or additional process steps.
Power, ground and signal routing Once components are placed, attention turns to routing voltage planes, including power and return planes and signal tracks to maintain board performance. Power and return planes should be symmetrical, centred and internal to the PCB. It is also recommended to keep power and ground tracks solid and wide to ensure stable voltage and minimise interference. Signal tracks should be kept as short and
direct as possible between components. On multilayer boards, if one layer contains horizontal tracks, the subsequent layer should be routed vertically to maintain proper separation. High-speed digital signals are often routed on inner layers, where they can be shielded by power planes to help reduce electromagnetic interference (EMI/EMC).
Defining Net Widths is also critical. Track widths should be calculated to meet current-carrying requirements, maintain the desired impedance and ensure proper isolation and acceptable temperature rise.
Circuit separation
Power circuits carrying high voltage or current can disrupt sensitive control circuits if not properly segregated. An experienced designer will maintain distinct grounds for power and control circuits wherever possible, and if a shared path is unavoidable, position it near the end of the supply chain. When the ground plane is in a middle layer, incorporating a small impedance path can help minimise the risk of interference from power circuits. To reduce capacitive coupling caused by the placement of a large ground plane and the lines routed above and below it, each signal should reference the correct plane, with digital signals connected to digital ground and analogue signals connected to analogue ground. Designers should also avoid crossing different signal domains to prevent interference.
Managing heat
Heat dissipation is a critical, yet often overlooked, aspect of PCB design. Components expected to generate significant heat should be distributed across the board to avoid hotspots. Thermal relief patterns help maintain consistent temperatures and ensure manufacturability, particularly on boards with high copper content or those designed for wave
Verification and rule checks No design is complete without thorough verification. Electrical Rules Checks (ERC) and Design Rules Checks (DRC) identify potential layout issues before production, helping prevent costly errors. Multiple rounds of checks can save both time and resources, ensuring the board is ready for manufacturing on the first attempt. Structured training for better PCB design Structured training and certification play a crucial role in improving PCB design quality. Industry-recognised programmes provide designers with a thorough understanding of design considerations, materials, assembly processes and documentation, as well as advanced techniques for those with practical experience. Such courses ensure that engineers consistently apply best practices across projects, enhancing manufacturability, reliability and cost- efficiency.
By following these five guidelines and integrating professional development, designers can produce PCBs that are not only functional but can be manufactured successfully. Applying Design for eXcellence principles alongside structured training reduces redesigns and ensures even complex boards meet the demands of modern electronics manufacturing.
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soldering processes. Choosing PCB materials with an appropriate glass transition temperature (Tg) and suitable thermal characteristics ensures the board can withstand operational conditions without failure.
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