DFT / ATPG · All levels

BIST Signoff: Review Checklist

Review Checklist for BIST Signoff.

Review checklist

Review Checklist for BIST Signoff focuses on MBIST/LBIST pass criteria, startup test time, in-field diagnostic readiness. The goal is to convert metric movement into mechanism, owner, and release decision.

  • Run tags and scenario context are explicit.

  • Constraints and legality assumptions are documented.

  • Quality, timing, and test-power checks are included.

  • Diagnosis evidence supports residual-risk decision.

  • Owners signed: DFT lead, product test owner, quality owner.

Signoff ownership

diagram
OWNERSHIP MAP - BIST Signoff

artifact              owner
----------------      -----------------
architecture/report DFT lead
constraints/setup   product test owner
physical/test       quality owner

Name an owner for each failing metric cluster.

DFT deep dive

BIST value is realized only when insertion, diagnosis, and repair are tied to production flow.

Concept diagram

diagram
BIST FLOW

insert MBIST/LBIST -> execute -> collect signatures -> diagnose/repair -> signoff

Metric graph

diagram
REPAIR EFFECT

yield
  ^
  |      o pre-repair
  |             o post-repair
  +---------------------> lot

Reports and artifacts

  • MBIST insertion coverage

  • repair signature report

  • LBIST resistant fault list

  • BIST release checklist

Mini case study

Fuse programming mismatch blocked repair activation; corrected bring-up script recovered expected yield uplift.

Debug branches

  • Validate BIST reachability

  • Correlate fail maps to repair signatures

  • Audit in-field boot test budget

Senior review question

Ask: what evidence proves this DFT decision is safe for production?

Key takeaways

  • State metric, lot/corner context, and pattern tag with every claim.

  • Treat timing, power, and quality as one signoff problem.

Common pitfalls

  • Chasing coverage without legality checks.

  • Ignoring test-power side effects of pattern changes.

  • Debugging silicon without reproducible tags.

Principal DFT review addendum

BIST signoff verifies architecture correctness, quality targets, safety intent, and production programmability before release.

Metric: MBIST/LBIST pass criteria, startup test time, in-field diagnostic readiness