3 Things to Check Before Sending Your PCB for Manufacturing

That moment when you’re ready to send your PCB design for manufacturing is both exciting and nerve-wracking. You’ve spent weeks, perhaps months perfecting your circuit, but rushing to production now could lead to costly mistakes and frustrating delays.

Before you hit that send button, take the time to verify these three critical elements. These final checks can mean the difference between a smooth manufacturing process and an expensive lesson in what not to do.

1. Design Verification: The Foundation of Success

Design errors are the most common and costly mistakes in PCB manufacturing. Once your board hits production, even minor oversights can lead to non-functional prototypes or, worse, reliability issues that only surface after deployment.

Layout and Connectivity

Double-check these design elements with particular attention:

• Trace width and spacing: Confirm that all traces meet your manufacturer’s minimum specifications. A trace that’s too narrow might not survive etching, while inadequate spacing can lead to shorts during manufacturing or in the field.
  
• Drill sizes and pad diameters: Verify that hole sizes are appropriate for your components and that annular rings have sufficient copper. Too little copper around a hole is a recipe for lifted pads during assembly.
  
• Layer stackup: Review your layer arrangement one final time. Are power and ground planes correctly positioned? Is your impedance control properly implemented on critical signal layers?
  
• Design rule check (DRC): Run a final DRC with your manufacturer’s specific parameters, not just your CAD software’s defaults. Many fabricators provide design rule files that you can import into your design software.
  

File Completeness

Having all the necessary files ready prevents delays and miscommunication:

• Gerber files: Ensure you’ve generated all required Gerber files, including copper layers, solder mask, silkscreen, and drill drawings. Follow your manufacturer’s naming conventions if specified.
  
• Drill files: Verify that your drill file includes all holes with the correct sizes and positions. Missing or incorrect drill information is a common source of manufacturing delays.
  
• Fabrication drawing: This crucial document specifies board dimensions, material, copper weight, and special requirements. Without clear specifications, manufacturers must make assumptions—which might not align with your needs.
  
• Assembly drawings: If you’re also ordering assembly services, provide clear component placement information, including orientation for polarized components.

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2. Bill of Materials (BOM): The Parts That Make It All Work

Even a perfectly designed PCB is useless without the right components. Your BOM is the manufacturing roadmap for your circuit, and any errors here can cascade into significant issues.

Component Specification

Clarity and precision in your BOM prevent assembly errors:

• Complete part numbers: Use full manufacturer part numbers rather than generic descriptions. “10k resistor” is insufficient; specify “RC0603FR-0710KL” (or similar) to ensure the exact component is used.
  
• Package verification: Double-check that footprints on your PCB match the physical packages specified in your BOM. The same component might come in multiple packages (SOT-23, SOIC, etc.), and mismatches cause assembly failures.
  
• Component availability: Verify that your specified components are currently available from distributors. The best design in the world can’t overcome supply chain issues with obsolete or backordered parts.
  
• Alternatives and substitutions: For critical components with potential supply issues, identify acceptable alternatives in advance. This gives your assembler options if your first choice isn’t available.
  

Special Requirements

Note any specific handling needs:

• Moisture-sensitive components: Identify components requiring special handling due to moisture sensitivity. These may need dry packing or baking before assembly.
  
• ESD-sensitive parts: Mark components needing electrostatic discharge precautions during assembly.
  
• Temperature restrictions: Note any components with specific reflow temperature limitations that might require special soldering processes.
  
• RoHS/REACH compliance: Confirm whether your project requires compliance with environmental regulations and verify that all components meet these standards.

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3. Budget Reality Check: Making the Numbers Work

Before committing to manufacturing, ensure that your project remains economically viable. Production costs can quickly escalate without proper planning and consideration.

Manufacturing Cost Analysis

Review all elements contributing to your PCB production cost:

• Board specifications vs. cost: Are you specifying tighter tolerances than your application actually requires? Standard tolerances are significantly cheaper than high-precision specifications.
  
• Panel utilisation: Could your board be redesigned slightly to fit more efficiently on a standard panel size? Better utilisation can substantially reduce per-unit costs.
  
• Volume considerations: Have you selected the optimal order quantity? There’s often a sweet spot where the per-unit price drops significantly without overcommitting to inventory you don’t need.
  
• Special processes: Review whether all specified special processes (gold plating, impedance control, etc.) are actually necessary for your application. Each adds cost that might not deliver proportional value.
  

Total Project Economics

Look beyond just the PCB to ensure overall project viability:

• Assembly costs: Factor in component placement, soldering, and testing expenses. These often exceed the bare board cost, especially for complex designs.
  
• Testing requirements: Consider how you’ll verify board functionality. Will you need custom test fixtures or programming setups? These costs can be significant but are often overlooked.
  
• Rework allowance: Budget for potential rework if issues arise. First production runs rarely go perfectly, and having financial headroom prevents project derailment.
  
• Project timeline vs. cost: Evaluate whether expedited production is worth the premium. Rush charges can double or triple manufacturing costs, potentially making a project economically unviable.

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Final Thoughts: The Pre-Manufacturing Checklist

Before sending your design to your PCB manufacturer, create a simple checklist covering these three critical areas:

✅ Design Verification

• All DRC errors resolved
• All files generated and verified
• Fabrication notes and drawings complete

✅ Bill of Materials

• All components specified with full part numbers
• Package types verified against layout
• Availability confirmed for all components

✅ Budget Considerations

• Manufacturing quotes reviewed and approved
• Total project cost calculated and verified against budget
• Cost-saving opportunities evaluated

Taking the time to methodically work through these checks won’t just save money - it will reduce stress, prevent delays, and help ensure your project’s success.

At ABL Circuits, we’re committed to helping our customers navigate the PCB manufacturing process with confidence. Our team is always available to review your designs and provide guidance before production begins, helping you avoid common pitfalls and achieve the best possible results.

Call ABL Circuits on 01462 894312 to learn more about our PCB design and PCB manufacturing services.

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