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Wafer Sort Review
From failing lot to signed-off decision.
Stratum is wafer sort review software for mixed-signal and analog teams. Start with the lot. Investigate the excursion, evaluate PAT or DPAT screens, and see exactly which dies move before anyone signs off.
Move the limits. Watch the review change.
Drag the proposed limits below. Stratum recalculates yield and changed dies against the scoped lot while the scatter and histogram stay in sync. The same data is available in SQL and Python when the charts are not enough.
Drag the limit lines to see the review update in real time.
Example review
Lot 18A7 ยท SKEW_CLK
HistogramFull lot
Baseline windowProposed LSLProposed USLIn windowOutside window
Workflow
The lot remains the unit of review.
Ingest creates the snapshot. Every investigation, screen, decision, and export points back to it, so a reviewer can follow how the result was reached.
- 01
Ingest
Upload STDF, confirm the parsed metadata, and preserve the lot as a reviewable snapshot.
- 02
Investigate
Use linked scatter, histogram, wafer, and spatial views to isolate the population that matters.
- 03
Screen
Evaluate PAT and DPAT screens alongside manual limit proposals without changing context.
- 04
Decide
Measure the die-level impact and record the rationale, review status, and approval.
- 05
Export
Deliver the CSV die list for operations and a review artifact for management.
Core Capabilities
Analysis that survives review.
Stratum keeps a proposed screen connected to its measured impact and review history.
Screening in context
Generate PAT or DPAT screens from the current lot or a reference lot, then carry the proposal into review.
Exact die-level review
What-if proposals resolve to exact outcomes with rescued dies, new fails, top impacted tests, and top impacted wafers.
Audit trail and sign-off
Versioned notebook documents retain the proposal, rationale, review status, and exported artifact.
Controlled collaboration
Role-based spaces and approval boundaries give engineers room to investigate without weakening review control.
Who It Is For
For the people accountable for the result.
Yield and test engineers
Move from excursion to a proposal another engineer can reproduce, with the die list and supporting analysis attached.
Engineering managers and quality leads
Review the proposed change and its measured impact in one artifact, with the history available when questions come back.
Working with one file locally? Open stdf.io.
Bring us a difficult lot.
We will work through the review with your team and measure the die-level impact before anything reaches sign-off.