Rule-based AOI flags too much, and real defects drown in the noise. Rather than rip out the line, this plant added a DaoAI AI adjudication layer after the AOI so operators only see real problems.
Consumer-electronics PCBA lines run fast and mix many board types, and post-reflow inspection leans heavily on legacy AOI. But rule and template matching is acutely sensitive to solder glare, component tolerance, and print offset, alarming at the slightest variation. This plant's real false-call rate ran high for years; its re-review stations ran three shifts, and operators manually re-confirmed tens of thousands of mis-flagged sites a day, so genuine defects were easily passed through under fatigue.
The team did not want to scrap an AOI already in production. They kept it as a coarse first pass and added DaoAI AI-AOI software behind it as a second gate: every site the legacy AOI called NG was re-adjudicated by the DaoAI model first. Using APDT positive- and few-sample learning, a station model went live on just a dozen-odd good-board images plus a few historical false-call images, with no need to amass large defect sets. Semantic false-call filtering recognized glare and in-tolerance offsets as good, leaving only real bridges, insufficient solder, and shifts.
What was deployed
- Legacy AOI retained as the first pass; DaoAI AI-AOI software as the second AI adjudication gate
- APDT positive-sample learning: 10–20 good images plus a few historical false calls per station to go live
- Semantic false-call filtering separates 'glare / in-tolerance offset' from 'real solder defects'
- 5-minute zero-code changeover lets a new board type switch in-shift without stopping the line
Not one machine was replaced; the line simply learned to alarm only when it should.
After go-live, sites needing manual re-review fell about 80%, the re-review stations were trimmed from three shifts, overall false calls dropped about 80%, and escapes stayed under 1%. Changeover shrank from tens of minutes of line-stopped tuning to the 5-minute range, and engineers no longer rewrote rules for each new board.