PCB DFM/DFA Analysis Guide
Provide one-stop Design for Manufacturability/Design for Assembly analysis solutions for PCB engineers, hardware designers and purchasers to ensure design compatibility with mass production, reduce costs and defect rates.
Design Manufacturability Index (DMI) Analysis
Core Value of DFM
Identify 98% of process conflicts before production starts through automated PRC on Gerber files.
1. DFM: Bare Board Fabrication
IPC-2221 StandardsOuter copper weight affects minimum trace capability.
Annular Rings must prevent breakouts during drilling.
The Solder Mask Bridge must be > 3mil.
Ratio of board thickness to drill diameter.
2. DFA: Assembly Analysis
Focuses on solder quality, Pick & Place efficiency, and DFT.
Component Shadowing
Avoid "shadows" during wave soldering from tall components.
Thermal Relief Balance
Mandatory for 0402 pads connecting to large planes.
Tombstoning Prevention
Imbalanced surface tension during reflow causes lifting. Use thermal reliefs to balance heat.
3. Common DFM/DFA Problem Diagnosis & Optimization Solutions
Provide accurate diagnosis basis and practical optimization solutions for high-frequency PCB design problems, quickly solving manufacturing and assembly difficulties.
| Problem Type | Diagnosis Basis | Potential Risks | Optimization Solutions |
|---|---|---|---|
| Excessive Via Aspect Ratio | Via diameter/board thickness > 1:6 (e.g., Φ0.2mm via used for 1.6mm board thickness, aspect ratio 1:8) | Uneven copper plating on hole walls, leading to poor signal transmission or reduced reliability | Increase via diameter (e.g., change to Φ0.3mm), or adopt blind/buried via design to reduce single via aspect ratio |
| Insufficient Component Spacing | SMD component spacing < 0.15mm, or spacing between SMD and through-hole components < 2.0mm | Bridging, cold soldering during soldering, or component offset during placement | Adjust component layout to increase spacing to standard value; if space is limited, adopt solder mask isolation or change component package |
| Mismatched Pad Size | Error between pad size and component pin size > ±0.1mm | Insufficient soldering strength, components easy to fall off, or bridging and cold soldering occur | Correct pad size according to IPC-7351B standard, e.g., 0402 component pads unified to 0.6mm × 0.3mm |
| Unreasonable Thermal Via Layout | No thermal vias under heating components, or thermal via spacing > 2.0mm | Excessively high component temperature, shortened service life, and even thermal failure | Evenly arrange Φ0.4mm thermal vias in the center and around heating components, spacing ≤ 1.5mm, quantity ≥ 4 |
| Components Too Close to Board Edge | Components < 2.0mm from the board edge | Component damage and line breakage during board separation, affecting product yield | Adjust component position to ensure ≥ 2.0mm from the board edge; if space is limited, increase board edge margin or adopt V-CUT board separation process |
