Key Insights for Every PCB Designer
In the world of Printed Circuit Board (PCB) design, cost-effectiveness is a crucial factor, and Greg Albers, the chief PCB designer at Sierra Circuits, has some valuable advice for designers. With 30 years of experience in the industry, including stints with several major OEMs, Albers emphasises the importance of "thinking big" when it comes to PCB design.
One of the key areas where cost-saving strategies can be implemented is in footprint development. Albers recommends creating proper footprints by referencing the data sheet for every part on every Bill of Materials (BOM). Using industry-standard footprints aligned with manufacturer libraries and capabilities rather than custom or overly complex footprints is a more economical approach. Optimising component placement tightly without compromising thermal and signal integrity reduces board size and material costs.
Via size, spacing, and location is the most challenging task in PCB design, but it also presents opportunities for cost savings. Choosing standard via sizes and spacing that most manufacturers can handle without additional cost premiums is essential. For example, maintaining minimum via drill sizes around 0.25 mm and standard spacing (e.g., 6 mil or 0.152 mm minimum trace and spacing rules) avoids specialized drilling or tighter tolerances that increase costs.
Simplifying layer counts and avoiding unnecessarily complex routing or tight tolerances that can cause fabrication errors and reduce yield rates is another cost-saving strategy. Higher complexity with tight trace widths/spacings or many layers often increases defect rates and costs due to lower yields and rework.
When it comes to BGA selection, using BGAs with pitch and pad sizes that conform to standard manufacturing capabilities is advisable. Larger pitches and standard footprints reduce the risk of solder bridging or misalignment, improving yield.
Panelization, the process of grouping multiple PCBs in one panel, is another effective cost-saving method. It decreases material waste and manufacturing time, potentially cutting costs by up to 25%. Panelization also simplifies quality control and assembly logistics.
Engaging in Design for Manufacturability (DFM) reviews with manufacturers early in the design process is another important strategy. This helps identify costly design features and optimise for better yields and lower total cost of ownership rather than just focusing on unit price.
Finally, using standard copper weights, substrate thicknesses, and widely available materials is advisable to avoid premium pricing for exotic or specialized materials.
In conclusion, cost-effective PCB manufacturing relies on adhering to industry-standard footprints with optimal but not overcomplicated layout, standardising via sizes and spacing, minimising layer counts and intricate fabrication steps to maximise yield, and selecting BGA packages with manageable pitch and pad sizes. Panelization and collaborative DFM assessments further enhance cost efficiency and reliability throughout the manufacturing process.
Adopting education-and-self-development courses on the latest trends in technology related to PCB design could help designers expand their skills and make more cost-effective decisions in their lifestyle.
After mastering the art of PCB design cost-effectively, sports activities, such as jogging or cycling, could serve as a stress-reliever, enhancing designers' overall productivity and performance in their work.
