01
Problem
A life-support PCBA required validated inspection and functional test methods to ensure critical electrical and solder-quality defects were detected before release.
02
Constraints
- High component density and small packages increased inspection difficulty.
- Critical functional parameters required repeatable measurement systems.
- IPC-A-610 Class 3 acceptance expectations applied to solder and assembly quality.
- Seeded-defect challenges had to demonstrate detection capability.
03
Engineering Decisions
- Used seeded-defect boards to challenge AOI detection logic.
- Applied known-good boards for functional tester verification.
- Separated attribute inspection validation from variable functional measurement validation.
- Created regression checks for test sequences.
04
Validation
- Executed AOI attribute validation against known defect states.
- Performed variable Gage R&R on critical electrical measurements.
- Confirmed detection and measurement performance before production release.
05
Risk & Mitigation
- AOI false calls could burden production; mitigated through lighting and library tuning.
- Fixture wear could degrade test performance; mitigated through pogo-pin maintenance controls.
- Uncontrolled test software changes could invalidate validation; mitigated through release control.
06
Outcome
A validated PCBA test strategy was established for mechanical and electrical product acceptance in a regulated environment.