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3.10 Data Logging & Repair Tickets (THT/Mixed)

The manual and mixed-technology assembly process—process — especially THT insertion, wave soldering, and high-risk rework — generates the most critical quality data. This chapter outlines the mandatory logging requirements and the Repair Ticket system, ensuring that every failure is contained, fixed, and traced back to its root process (design, material, or assembly). By establishing a disciplined data flow, manufacturers turn isolated fixes into systematic, auditable process improvements.

2.5.3.10.1 The Data Mandate: Traceability in Manual Processes

The Manufacturing Execution System (MES) traveler must capture detailed, specific evidence for all manual and automated THT steps. This data supports repair and future Corrective and Preventive Action (CAPA).

The Record Must Contain (Per Serial Number)

  • Identity & Context: Product/Revision, Serial Number (SN), Work Order (WO).
  • Genealogy: PCB lot, THT component lots (e.g., connectors), Pallet ID (if used).
  • Process Parameters: Wave/Selective Recipe ID, Top-Side Temperature achieved during preheat, manual assembly station ID.
  • Inspection: AXI/AOI links, visual inspection checkpoints (VIs).
  • Rework History: Repair Ticket ID, Defect Code, Attempt Count, Parts Replaced, Thermal Cycles Logged (for high-risk components).

2.5.3.10.2 THT-Specific Defect Codes

Defect codes must be granular enough to point directly to the failing process or design characteristic. THT and mixed-technology defects fall into three primary process families: Preparation, Soldering, and Post-Solder.

Family

Code

Symptom and Root Cause

Process Owner

Preparation

FLUX-STARVED

Missing or inadequate flux coverage before wave/selective.

Fluxing/Preheat


THERM-SHOCK

Component (e.g., ceramic cap) cracking due to high ∆T.

Preheat/Profiling

Soldering

NON-FILL-TS

Poor top-side barrel fill (THT barrel/hole design or low heat).

Process Eng. / DFM


BRIDGE-THT

Solder bridge between adjacent THT pins (poor wave exit/angle/thief).

Wave/Selective Setup


ICICLE

Excessive solder peaks/spears on pins (peel control failure).

Wave/Selective Setup

Rework

PAD-LIFT

Damage to copper pad/trace during manual touch-up or removal.

Rework Tech / Tooling


HIP-REWORK

Head-in-Pillow created during BGA rework reflow.

Rework Profile

Mandate: Every failure must be logged with a controlled code. Free-text notes are only allowed to elaborate on the context of the code, not to replace it.

2.5.3.10.3 Rework Flow and Traceability Control

When a unit fails at inspection (e.g., AOI or VI), the MES initiates a strict sequence to ensure audit compliance.

  1. Fail – Ticket: The unit is scanned to NG-QUAR (Quarantine), and a Repair Ticket is auto-generated, linking the Defect Code and Operator ID.
  2. Rework Action: The Repair Technician claims the ticket and logs:
    • The Standard Work Instruction (SWI) ID used (e.g., IPC-7711/7721 trace repair procedure).
    • The Rework Tool/Profile ID (especially for BGA/QFN hot-air reflow).
    • The new Component Lot/Date Code if a part was replaced (Genealogy Update).
  3. Attempt Tracking: The system must increment the Attempt Count field every time a repair heat cycle is applied to a specific component or site. This enforces the max thermal cycle limit (e.g., BGA ≤ 2 attempts).
  4. Verification Route: After the repair, the MES dictates the mandatory re-inspection route. The unit must pass the failing gate again (e.g., VI re-inspection, FCT spot check) before its status is set to PASS.

Rule: A component or board must never leave the rework area without logging the attempt count and passing the required verification.

2.5.3.10.4 Metrics for Process Improvement

The logged defect data must be used to calculate KPIs that drive CAPA actions and reduce the Cost of Poor Quality (CoPQ).

  • First Pass Yield (FPY): Overall measure of process stability.
  • MTTR (Mean Time To Repair): Tracks repair efficiency by defect code and technician.
  • Top-10 Pareto: Weekly analysis of the highest frequency defect codes. If NON-FILL-TS or BRIDGE-THT are consistently high, the problem is a DFM design issue  (Chapter 1.1) or a process setup failure (Chapter 1.4), not operator error.
  • Supplier Quality: Rework materials and replacement part lots (genealogy) are flagged to trigger SCAR (Supplier Corrective Action Request) if a defect code is linked to a specific material lot.

Final Checklist: THT Traceability and Rework Controls

Mandate

Criteria

Verification Action

Process Genealogy

Pallet ID, Wave/Selective Recipe ID, and Top-Side Temperature logged per SN.

Ensures every assembly is traceable to the exact machine parameters used.

THT Defect Logging

Failures are logged with a controlled code (e.g., NON-FILL-TS, ICICLE) and evidence attached.

Defect codes must be granular enough to point to the correct process owner (DFM or Process).

Heat Cycle Limit

The Attempt Count is tracked per site for high-risk components (BGAs/QFNs).

Attempt count must be ≤ the product's maximum thermal cycle limit (e.g., ≤ 2 reflows).

Verification Route

Unit must re-pass the original failing gate (e.g., VI or FCT) after the repair.

MES must automatically enforce the re-inspection sequence before setting PASS status.

Component Genealogy

Replacement part lot codes must be scanned and linked to the SN's history.

Maintains a complete, auditable record of which component is now in the assembly.


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