• fab-PCBA-dat - fab-soldering-dat

• fab-PCB-dat - fab-PCB-tools-dat

• PCB-soldering-dat - desoldering-dat

• spot-welding-dat

• solder-paste-dat - soldering-tools-dat

• PCB-dat

• PNP-machine-dat - reflow-machine-dat

• PCB-cleaner-dat - PCB-clean-dat

soldering under microscope

• RP2040-dat

PCBA

• include extra assembly, files

PCBA Design

• PCB-dat

• penalization-dat - EDA-dat

PCB-make-dat

• mark-point-dat - export-coordinate-dat

make machine

machine-dat - pnp-machine-dat

PCB protection service

• for this module, consider add - Adhesive Solutions on PCBs - PCB-Adhesive-dat
• or layered plastic case layered-case-dat
• more simple soltuion - PMP1037-dat

Automated Methods to Check Complex Footprints (Unsoldered Pads)

• AOI-dat - ICT-dat

• E-test-dat

• E-Test is for the bare PCB (before assembly).

• It checks copper traces, vias, and pads for:
  • Short circuits (unwanted connections between nets).
  • Open circuits (broken or missing connections).
• Done by the PCB manufacturer using a flying probe tester or a bed-of-nails fixture.
• Ensures the bare board matches the Gerber/netlist before any components are soldered.

Method	How It Works	Pros	Cons
Automated Optical Inspection (AOI)	High-resolution cameras scan PCB to compare against "golden board" or Gerber. Detects shorts, opens, mask issues, pad misalignment.	Fast, widely used in PCB fab & assembly.	Limited for hidden pads (BGA bottom side).
Flying Probe Test	Robotic probes touch each pad/net and check connectivity vs netlist.	No test fixture needed, flexible, high accuracy.	Slower than bed-of-nails, not good for high volume.
In-Circuit Test (ICT / Bed-of-Nails)	Custom test fixture presses spring pins into test pads, verifying continuity, isolation, resistance, etc.	Very fast, accurate, used for production.	Expensive setup, needs test points designed in.
X-Ray Inspection (AXI)	X-ray scans to detect hidden bridges, voids, and pad geometry (great for BGA/QFN).	Can see under packages, detects hidden issues.	Expensive equipment, slower than AOI.
Electrical Netlist Test (Bare Board E-Test)	PCB fab tests each board against Gerber netlist for shorts/opens using a flying probe.	Ensures PCB is correct before assembly.	Only checks copper nets, not mask/pad alignment.
Solder Paste Inspection (SPI)	3D laser scan checks solder paste deposits on pads.	Ensures correct stencil printing before reflow.	Only useful after paste printing stage.
Coplanarity / Surface Profiling	Laser or white-light interferometer scans pads for height/flatness.	Ensures pads are level for fine-pitch ICs.	More common in IC packaging QA.

---

Typical Workflow in Production

1. Bare PCB stage → Electrical netlist test + AOI.
   
2. Assembly stage (before soldering ICs) → AOI for pad/solder mask check, SPI for solder paste.
   
3. After soldering → AOI again + X-ray for BGA/QFN.
   
4. Final board → ICT (bed-of-nails) or flying probe for electrical verification.
   

---

👉 For prototyping / small batch, fabs usually run bare board E-test + AOI already.
👉 For hidden pad packages (QFN/BGA), the only real automated detection is X-ray.

ref

• fab-dat

• fab-PCBA