Assembly Parameters
Enter your PCB assembly specifications
Cost Breakdown
Estimated assembly pricing
Lead Time Estimate
5-7 Days
DFA Score: Good
Your design meets most Design for Assembly guidelines. Review the checklist below to identify areas for improvement and optimize your PCB for efficient assembly.
Component Placement
Placement optimization checks
Component Orientation Consistency
All polarized components should have consistent orientation (pin 1 facing same direction)
Adequate Component Spacing
Minimum 0.5mm spacing between components for pick-and-place accuracy
Fiducial Markers Present
Global and local fiducials for machine vision alignment (3 global minimum)
No Components Under BGA
Ensure no small components are placed directly under BGA packages
Soldering & Assembly
Manufacturing readiness checks
Proper Pad Sizing
Pad dimensions match IPC-7351 standards for reliable solder joints
Thermal Relief on Ground Pads
Large ground planes have thermal relief for easier soldering
Solder Mask Between Fine-Pitch
Minimum solder mask web of 75μm between fine-pitch pads
No Tombstoning Risk
Symmetric pad designs to prevent component tombstoning during reflow
DFA Best Practices
Key guidelines for optimizing assembly
Minimize Part Count
Reduce unique components to simplify BOM and lower assembly costs
Standard Packages
Use common package sizes (0402, 0603, 0805) for better availability
Panel Design
Optimize panel utilization with proper V-score or tab routing
Clear Documentation
Provide complete BOM, Gerbers, and assembly drawings
BOM Upload
Analyze your Bill of Materials
Drag & drop your BOM file here or click to browse
Supports CSV, Excel (.xlsx), or TSV formats
BOM Analysis Results
Component breakdown and insights
Upload or paste your BOM to see analysis results
PCB Assembly Process Flow
Understanding the SMT assembly workflow
Solder Paste Application
Solder paste is applied to the PCB pads using a stencil printer. The paste consists of tiny solder balls suspended in flux. Proper paste volume and alignment are critical for reliable solder joints.
Solder Paste Inspection (SPI)
3D inspection systems verify paste volume, height, and position on each pad. This early detection prevents defects before component placement, saving costly rework.
Component Placement
High-speed pick-and-place machines position SMD components onto the solder paste. Modern machines achieve speeds of 30,000+ components per hour with ±25μm accuracy.
Reflow Soldering
PCBs pass through a reflow oven with precisely controlled temperature zones. The solder paste melts and forms permanent connections. Lead-free profiles typically peak at 245-250°C.
Automated Optical Inspection (AOI)
High-resolution cameras inspect every solder joint for defects including bridges, insufficient solder, tombstoning, and missing components. AI algorithms enhance detection accuracy.
Through-Hole Assembly (if required)
THT components are inserted manually or with automated insertion machines, then soldered using wave soldering or selective soldering processes.
X-Ray Inspection (BGA/QFN)
For packages with hidden solder joints like BGA and QFN, X-ray inspection verifies solder ball integrity and detects voids or shorts beneath the package.
Functional Testing & ICT
In-Circuit Testing (ICT) verifies component values and connectivity. Functional testing confirms the board operates correctly under actual operating conditions.
Component Package Reference
Common SMD and THT package dimensions
| Package | Type | Size (mm) | Pitch | Assembly Difficulty |
|---|---|---|---|---|
| 0201 | SMD | 0.6 × 0.3 | N/A | ⚠️ Very Difficult |
| 0402 | SMD | 1.0 × 0.5 | N/A | ⚠️ Difficult |
| 0603 | SMD | 1.6 × 0.8 | N/A | ✅ Standard |
| 0805 | SMD | 2.0 × 1.25 | N/A | ✅ Easy |
| 1206 | SMD | 3.2 × 1.6 | N/A | ✅ Easy |
| SOT-23 | SMD | 2.9 × 1.3 | 0.95mm | ✅ Standard |
| SOIC-8 | SMD | 4.9 × 3.9 | 1.27mm | ✅ Easy |
| TQFP-44 | SMD | 10 × 10 | 0.8mm | ✅ Standard |
| QFN-32 | SMD | 5 × 5 | 0.5mm | ⚠️ Requires X-Ray |
| BGA-256 | BGA | 17 × 17 | 1.0mm | ⚠️ Requires X-Ray |
| DIP-8 | THT | 9.5 × 6.4 | 2.54mm | ✅ Easy |
| TO-220 | THT | 10.0 × 4.5 | 2.54mm | ✅ Easy |
0402 Considerations
Requires precision stencils (4-5 mil thickness) and accurate paste deposition. Not recommended for hand assembly.
BGA Reliability
BGAs require X-ray inspection for quality assurance. Proper reflow profiles are critical to prevent solder ball voiding.
THT vs SMD
THT components add manual labor cost but provide stronger mechanical connections for connectors and high-stress parts.
Stencil Calculator
Calculate optimal stencil parameters
Recommended Parameters
Optimal stencil specifications
Recommended Stencil Thickness
4mil
💡 Recommendations
- Use electropolished stainless steel for best paste release
- Consider nano-coating for fine-pitch applications
- Ensure aperture area ratio > 0.66 for reliable paste transfer