PCBA Testing: 3 Checks Every Board Must Pass Before Shipping

2026-05-21

You receive your PCBA order. It looks fine. But will it work after 100 hours of operation?

Testing separates reliable manufacturers from cheap assemblers.

1. Automated Optical Inspection (AOI)

What it catches: Solder bridges, missing components, polarity errors, tombstoning
Why it matters: Human eyes miss up to 20% of surface defects.
STG: 100% AOI on every board after reflow.

2. X-Ray Inspection (for BGA)

What it catches: Voids, cold joints, head-in-pillow defects under BGA components
Why it matters: You can't see under the chip. X-ray reveals hidden failures.
STG: X-ray on all BGA and QFN assemblies.

3. Functional Testing

What it catches: Board doesn't work as designed – wrong voltage, no signal, intermittent operation
Why it matters: Visual and X-ray checks pass, but the board may still fail.
STG: Custom test fixtures. We power your board and verify function.

The Cost of Skipping Tests

Missing Test Potential Consequence
AOI Solder bridge causes short in field
X-ray BGA void leads to intermittent failure
Functional Entire batch fails at customer site

One field failure can cost 10x your PCBA price.