pad-analysis

name	pad-analysis
description	Analyze pad-to-pad distances to detect spacing violations before DFM upload

Pad Distance Analysis

Analyze PCB pad-to-pad and pad-to-via edge distances to detect spacing violations.

Argument: Optional threshold in mm (default 0.15). Example: --threshold 0.20

CRITICAL: False Positive Filtering

The script reports ALL close pairs, but many are intentional:

• Traces connecting TO their target pad = same-net (OK)
• Vias adjacent to their connected pads = same-net (OK)
• Only different-net pairs with gap < threshold are real violations

Always filter results by net before acting on them.

Steps

1. Run analysis

cd /Users/pierrejonnycau/Documents/WORKS/esp32-emu-turbo
python3 scripts/analyze_pad_distances.py $ARGUMENTS

If no arguments provided, use default threshold:

python3 scripts/analyze_pad_distances.py --threshold 0.15

2. Parse results

From the output, create a categorized table:

Pair	Layer	Gap (mm)	Same Net?	Verdict
U1:1 ↔ C3:1	F.Cu	0.08	No	VIOLATION
J4:5 ↔ via	B.Cu	0.00	Yes	OK (intentional)

3. Identify real violations only

Filter out same-net pairs. Focus on:

• Different-net pairs with gap < 0.10mm → DANGER (JLCPCB will reject)
• Different-net pairs with gap 0.10-0.15mm → WARNING (may trigger DFM alert)
• Same-net pairs → IGNORE (intentional connections)

4. Map violations to source

For each real violation, identify the fix location:

Issue Type	Fix File	Fix Action
Pad-to-pad too close	scripts/generate_pcb/board.py	Move component in _component_placeholders()
Via-to-pad too close	scripts/generate_pcb/routing.py	Move via position
Mounting hole clearance	scripts/generate_pcb/board.py	Increase hole-to-component gap

5. Summary

Print a summary:

• Total pairs analyzed
• Pairs below threshold (all)
• Same-net pairs filtered out
• Real violations remaining
• Recommended fix priority

Key Files

• scripts/analyze_pad_distances.py — Main analysis script
• scripts/generate_pcb/board.py — Component placement (fix positions here)
• scripts/generate_pcb/routing.py — Via/trace positions (fix routing here)