Optimizing PCB Manufacturing Costs: Design Adjustments to Enhance Production Efficiency

For PCB designers, understanding how specific design choices impact manufacturing can enable strategic adjustments to reduce production costs and simplify fabrication. The following analysis provides an in-depth look at how design features influence manufacturing challenges and cost, along with practical design modifications for optimizing expenses and production efficiency.

1. PCB Size and Panelization Strategy

PCB size and efficient panelization are crucial for cost management, especially in high-volume production:

• Panel Efficiency: Maximizing the number of boards on a single panel improves material utilization and reduces per-unit costs. Uniform rectangular designs, where possible, can optimize panel utilization and minimize waste.
• Material and Thickness Constraints: Some materials, like Rogers laminates, have specific panel size limitations. Board thickness also impacts spacing on panels, with thicker boards requiring more space between units, potentially lowering yield per panel.
• Edge Features and Component Overhang: Designs with edge connectors (e.g., gold fingers) or components extending beyond the board edges require additional spacing on the panel, reducing panel efficiency. Relocating components or modifying connector designs can help conserve panel space.

When designers optimize PCB size, panel arrangement, and layout, they can increase material yield and lower per-board costs, especially in bulk production. Adjusting edge features, thickness, and component positioning can further improve panel utilization and reduce waste.

2. Material Selection and Cost-Effective Alternatives

Material choice affects production cost, durability, and performance. Choosing the appropriate materials for specific layers can provide cost savings:

• Targeted Material Use: Specifying high-performance materials like Rogers or PTFE only for critical layers, while using standard FR-4 for other layers, reduces material costs while meeting performance needs.
• Optimizing Copper Weight and Prepreg: Heavy copper increases both material and process costs due to longer etching and added prepreg usage. Minimizing copper weight on non-critical layers reduces these expenses.
• Compliance and Standards Considerations: Certain industries require materials that meet specific environmental standards, such as RoHS. Avoiding over-specification by selecting materials that meet, but do not exceed, regulatory standards can prevent unnecessary costs.

Selecting materials based on application-specific needs and regulatory requirements helps designers balance cost and performance. Using premium materials only for essential layers and managing copper weight minimizes production expenses without sacrificing quality.

3. Layer Count Optimization and Stackup Design

Layer count directly impacts production complexity and cost. Streamlining the stackup can optimize layer usage and reduce costs:

• Consolidating Signal Layers: Efficiently combining signal paths on fewer layers lowers layer count, reduces material and labor costs, and minimizes manufacturing complexity.
• Thermally Stable Stackups: High-frequency applications require symmetrical stackups for thermal stability, but for general applications, asymmetrical stackups reduce material use and cost without sacrificing reliability.
• Minimizing Extra Processing Steps: By consolidating layers and optimizing routing, designers can reduce lamination cycles and bonding steps, leading to simpler and faster manufacturing.

Reducing unnecessary layers and consolidating signals improve cost-effectiveness and production efficiency. Selecting the right stackup for each application’s thermal and signal requirements ensures optimal performance while minimizing complexity and material use.

4. Reducing Design Complexity for Improved Manufacturability

Highly complex designs, while sometimes necessary, drive up production costs. Simplifying design elements where possible improves manufacturing feasibility:

• Reducing High-Density Features: Minimizing the use of microvias and dense via layouts reduces costs by lowering the need for laser drilling and additional inspection.
• Avoiding Custom Shapes: Non-standard board shapes are harder to panelize efficiently and often require custom routing, increasing production costs. Opting for standard shapes improves panel utilization.
• Standardizing Via Types: Sticking to common via types (e.g., avoiding blind or buried vias) reduces the need for specialized drilling equipment and inspection, streamlining production.

By limiting complex design features, such as microvias, intricate shapes, and customized vias, designers reduce the need for advanced equipment and processes, ultimately lowering manufacturing costs and increasing yield.

5. Optimizing Trace Width and Spacing

Trace width and spacing influence both manufacturability and production costs. Design adjustments can reduce etching complexity and improve yield:

• Using Standard Trace Widths: Standard trace widths simplify etching and reduce inspection requirements, lowering costs. Tight tolerances, while sometimes necessary, should be minimized where possible to reduce production difficulty.
• Reducing Conductor Density: High-density routing requires advanced etching techniques and increases inspection time. Avoiding unnecessary congestion in routing simplifies production and improves quality control efficiency.
• Relaxing Spacing Where Possible: Ensuring adequate spacing between traces reduces the risk of shorts, easing the etching process and decreasing the likelihood of rework.

Standardizing trace widths and spacing, and avoiding high-density routing, reduces etching complexity and inspection demands, cutting costs and improving manufacturability without compromising circuit functionality.

6. Hole Size and Quantity: Efficient Via Management

Hole requirements, including quantity, type, and size, influence drilling costs and time. Optimizing these factors can simplify manufacturing:

• Standardizing Hole Sizes: Using uniform hole sizes reduces tool change frequency and improves drilling efficiency. Minimizing size variation simplifies production and reduces material costs.
• Minimizing Microvias: Microvias are more costly due to precise laser drilling. Designers can prioritize through-hole vias for non-critical connections to control costs.
• Reducing Hole Density: Lower hole density reduces drilling time and associated costs. Optimizing hole placement and quantity minimizes both material and labor expenses.

Efficient via management helps control drilling costs, an important factor in high-density or multi-layer designs.

7. Controlled Impedance Optimization

Controlled impedance is crucial in high-speed designs but adds production complexity. Limiting its use to necessary areas can reduce costs:

• Applying Impedance Control Selectively: Limiting impedance control to essential signal paths reduces manufacturing complexity and cost by minimizing the need for tight tolerance and material restrictions.
• Selecting Impedance-Friendly Stackups: Designing stackups that naturally support impedance matching reduces the need for additional processing and testing, optimizing both performance and cost.
• Reducing Unnecessary Testing: For designs without high-speed requirements, avoiding impedance testing reduces time and inspection costs.

Applying controlled impedance only in necessary areas and choosing impedance-friendly stackups simplify production and reduce costs. Avoiding over-specification and unnecessary testing further optimizes manufacturing processes.

8. Tolerance Relaxation to Simplify Production

Tight tolerances increase production difficulty and inspection time. Relaxing tolerances in less critical areas reduces costs:

• Widening Mechanical Tolerances: Allowing more flexible tolerances for board dimensions and thickness reduces alignment and inspection needs, streamlining production.
• Relaxing Registration Accuracy: For applications without strict layer alignment needs, more lenient tolerances reduce registration time and simplify lamination processes.
• Reducing Electrical Tolerance Stringency: For non-high-speed boards, looser electrical tolerances in trace width or spacing simplify etching and reduce complexity.

Adjusting mechanical, registration, and electrical tolerances based on application needs simplifies production and minimizes costs associated with inspection and precision alignment, without impacting overall quality.

9. Copper Weight and Thickness Optimization

Copper thickness impacts both current-carrying capacity and cost. Optimizing copper distribution minimizes material and processing expenses:

• Reducing Copper Weight in Non-Critical Layers: Heavy copper layers should be reserved for power-demanding areas. Lighter copper can be used in less critical regions, reducing material and processing costs.
• Avoiding Excessive Copper in Signal Layers: In signal layers, where high current isn’t required, lighter copper prevents impedance issues and simplifies manufacturing.
• Improving Thermal Management through Design: Effective thermal design reduces reliance on heavy copper, lowering both material and etching costs.

Using copper weight strategically, only where necessary, reduces material and processing costs. Limiting heavy copper use to power layers and implementing thermal management in the design phase can provide significant cost savings.

10. Simplifying Soldermask, Silkscreen, and Carbon Print Layers

Additional layers such as soldermask, silkscreen, and carbon print add production steps. Cost-effective choices improve production efficiency:

• Using Standard Soldermask Options: Standard soldermask colors (e.g., green) and thicknesses reduce material costs and production time, while custom colors or thick soldermasks increase expenses.
• Minimizing Silkscreen Details: Simplified silkscreen designs with essential text and symbols improve printing speed and reduce material costs. Avoiding high-resolution requirements or intricate patterns saves both time and resources.
• Avoiding Unnecessary Layers: Carbon prints and other specialty layers require additional steps, increasing costs. Removing non-essential layers simplifies production and reduces labor requirements.

Simplifying soldermask, silkscreen, and additional layers streamlines production and minimizes material and labor costs. Opting for standard options and limiting details effectively balances functionality with cost-efficiency.

If you’re looking to optimize PCB costs but are unsure how to start, reach out to us at Highleap Electronic. Our team of experienced engineers offers one-on-one consultations to provide tailored advice on cost-effective design changes and practical manufacturing solutions. With a skilled engineering team well-versed in production challenges, we can help you refine your PCB design for both quality and cost efficiency based on real-world manufacturing insights.