CAPA Record
CAPA Reference / Source
- CAPA Number: TBD — pending Quality Management System assignment
- NCR Reference: NCR #26-0244
- Source: Internal detection via X-ray inspection and defect rate monitoring
- CAPA Owner: Anna (Process Engineer — last name not stated)
- Issue Date: June 10, 2026
Problem / Nonconformance Description
QFN-48 packages on Oven #1913 are exhibiting cold solder joints at 4.2% defect rate (84 defects / 2,000 joints inspected) beginning June 2, 2026, compared to 0.3% (6 defects / 2,000 joints combined) on Ovens #1911 and #1912 running the same paste lot, boards, and process concurrently — a 14x elevation isolated to one oven.
Failure location: Ground-pad thermal via array under QFN-48 packages — highest thermal-mass joint location on the IoT controller PCBA.
Applicable standards (rigor model): IPC-A-610 Class 2, J-STD-001 — as stated by the user; this is the quality rigor frame in use, not a claim of regulatory applicability beyond what the user confirmed.
Product affected: Industrial IoT controller PCBA (single product line, confirmed by Maria Sanchez's board PN traceability).
Customer exposure: 127 boards produced June 2–4, 2026 on Oven #1913 under AOI + visual inspection only (X-ray not applied during that window). All 127 boards identified in staging; shipment hold placed on Order #MIC-26-0487 (Midwest Industrial Controls) at 1:47 PM June 10, 2026 — no defective product has left the facility. 100% X-ray of all 127 boards initiated by Dan Kim, results pending by end of shift June 10, 2026.
Decisive Contrasts (IS / IS-NOT)
| Dimension | IS | IS NOT |
|---|---|---|
| What (defect) | Cold solder joints, QFN-48 thermal via array (ground pad) | Other joint types — TBD, pending Dan Kim's component-type breakdown |
| Where (equipment) | Oven #1913 | Ovens #1911, #1912 — same paste, same boards, 0.3% defect rate |
| Where (board location) | QFN-48 ground-pad via array | Other board locations — TBD, pending Dan Kim's X-ray distribution |
| When (onset) | June 2, 2026 onward | Before June 2, 2026; before Zone 7 drift and new paste lot coincided |
| How many (extent) | 4.2% (84/2,000 joints) on #1913 | ≤0.3% on #1911/#1912 running identical paste and boards |
| Who / which product | IoT controller PCBA (single product line, confirmed by Maria) | Other board designs — none identified in this run |
| Which material | Paste lot PST-26-0339 present on all three ovens (Ag 2.8%, liquidus 219°C) | Paste lot alone as sufficient cause — #1911/#1912 ran same lot at 0.3% |
Decisive contrast 1: Paste lot PST-26-0339 was distributed nearly evenly across all three ovens (~500 boards each, per Maria Sanchez's traceability pull) yet only #1913 shows elevated defects. This single contrast is what shifts the investigation from a paste-lot theory to an oven-specific theory.
Decisive contrast 2: The defect is isolated to one equipment unit while board design, stencil, placement, and components are confirmed identical across all three ovens. This points to a machine-specific variable, not a process-design or material-only variable.
Decisive contrast 3: Onset (June 2) trails the Zone 7 drift onset (May 29/30) by 2–3 days but trails the paste lot introduction (June 1) by only 1 day. This timing pattern is what drives the multi-factor interaction hypothesis rather than a single standalone cause.
6M Fishbone (breadth)
Machine
- Zone 7 thermal drift on Oven #1913 — CANDIDATE (RC-A): thermocouple logs confirm onset May 29/30, persistent -4°C to -6°C below setpoint through June 10
- Cause of drift (heater element / thermocouple / control card) — TBD: pending Raj Patel's diagnosis
- Legacy reflow profile difference across the three ovens — TBD: pending Raj's zone setpoint/conveyor speed comparison across #1913, #1911, #1912
- Nitrogen purity / flow rate on #1913 specifically — TBD: pending Raj verification
- KIC gold-board verification blind spot — CANDIDATE (RC-A / escape point): gold-board fixture does not replicate thermal mass of a populated QFN ground-pad via array
Material
- Paste lot PST-26-0339 (Ag 2.8% vs. 3.0% target, liquidus 219°C vs. 217°C) — CANDIDATE (RC-B): contributing condition confirmed; evenly distributed across all three ovens per Maria's traceability
- PCB lot consistency across ovens — TBD: pending Maria's component traceability pull
- QFN-48 component lot / moisture sensitivity / bake status — TBD: elevated priority per counter-evidence review; pending Maria
- Flux formulation delta on PST-26-0339 vs. prior lot — TBD: pending Maria's COA review
- Prior SAC305 paste lot history (12 months, Ag content, defect rates) — TBD: decisive for RC-B weight; pending Maria
Method
- Process recipe / reflow profile change on #1913 post-April 28 — RULED OUT: no documented changes since last KIC verification
- Stencil wear — RULED OUT: no issues flagged
- New squeegee installation, WO-26-0610 (May 30, 2026) — TBD, elevated: SPI volume data shows paste volume within ±10% across all three ovens, but height-map/profile data at the via-array aperture has not been reviewed; SPI system capability itself unconfirmed
- Board storage / humidity conditions — TBD: pending Maria
Man (People)
- Intentional operator or recipe adjustment on #1913 around May 29/30 — NOT CURRENTLY SUPPORTED: the spike-and-degrade drift pattern in Raj's thermocouple logs is inconsistent with an immediate, sustained setpoint change; not yet confirmed ruled out — Raj to verify no manual adjustments or work orders in that window
- Skill gap or training issue — probed further, nothing additional surfaced: no operator changes documented, no process deviations flagged during the investigation
Measurement
- SPI paste volume monitoring — RULED OUT as a volume-related cause: functioning normally, ±10% of target across all three ovens; height-map capability (separate question) remains TBD
- AOI-only inspection June 2–4 — CONFIRMED escape point (EP-3): insufficient method for subsurface cold joints at the via array; X-ray required for this failure mode
- KIC gold-board verification cadence (90-day) — CONFIRMED escape point contributor (EP-1 related): does not capture inter-verification zone drift or localized high-thermal-mass performance
Mother Nature (Environment)
- Ambient temperature / humidity / airflow differences around #1913 — TBD, low probability: oven-specific defect pattern and even paste distribution argue against environment as primary driver; physical layout confirmation pending floor walk by Anna / Linda Chen
- Nitrogen atmosphere on #1913 specifically — TBD: pending Raj verification
5-Why Chain
Chain A — Machine (Primary)
- Why 1: Cold solder joints on QFN-48 via arrays on #1913
→ Insufficient thermal energy delivered to QFN ground-pad via array during reflow TAL window
→ Evidence: 84/2,000 joints defective on #1913 vs. 6/2,000 combined on #1911/#1912 — Dan Kim's X-ray data
- Why 2: Insufficient thermal energy at the via array
→ Zone 7 on #1913 running -4°C to -6°C below setpoint, reducing heat delivery to the highest thermal-mass joint location on the board
→ Evidence: Raj Patel's thermocouple trend logs — drift onset May 29/30, 2026 at 11:47 PM; persistent through June 10, 2026
- Why 3: Zone 7 running below setpoint
→ Hardware failure (heater element, thermocouple, or control card) — spike-and-degrade pattern is consistent with hardware degradation rather than a setpoint change
→ Evidence: thermocouple logs show intermittent spikes to -3°C beginning May 29, stabilizing at persistent -4°C to -6°C from May 30; specific failed component TBD pending Raj's diagnosis
- Why 4: Zone 7 drift not detected before defects appeared June 2
→ No automated alarm triggered or escalated when drift began; KIC gold-board verification cadence (90-day) did not catch inter-verification drift; product-specific profiling not in protocol
→ Evidence: Raj noticed drift manually "week of June 1" rather than through an automated alert; last KIC verification April 28, 2026 passed; alarm configuration status TBD
- Why 5: Detection system failed to catch a sustained zone temperature deviation
→ Oven monitoring protocol relies on periodic gold-board KIC verification rather than continuous zone-level deviation alerting; gold-board fixture does not replicate the thermal behavior of a populated high-thermal-mass joint; product-specific profiling not required by current SOP
→ Evidence: SOP design-vs-execution status TBD pending control plan review; alarm configuration TBD pending Raj's diagnosis
Chain B — Material (Contributing)
- Why 1: Zone 7 undershoot produced cold joints beginning June 2 but not May 29–31
→ PST-26-0339 (introduced June 1) has elevated liquidus (219°C vs. 217°C on prior lot), reducing thermal margin at the via array
→ Evidence: PST-26-0339 supplier COA — Ag 2.8% vs. 3.0% standard, liquidus 219°C; Maria's distribution data — all three ovens ran the lot at roughly equal volume
- Why 2: Paste lot with reduced Ag and elevated liquidus released to the line
→ Incoming inspection either did not check COA Ag content against internal acceptance limits, or internal limits do not adequately constrain paste lots for the facility's thermal conditions
→ Evidence: incoming QC procedure and acceptance criteria TBD pending Maria's review
- Why 3: Incoming inspection did not catch or flag the Ag deviation
→ Either internal limit matches J-STD-006 range (2.5–4.0%) rather than a tighter ≥3.0% process requirement, or the COA was not reviewed against internal limits before release
→ Evidence: control plan / SOP review pending — Anna
- Why 4: Incoming acceptance criteria do not adequately constrain paste lots for the facility's thermal conditions
→ Acceptance criteria may be set to supplier specification rather than process-capability-based limits accounting for worst-case oven thermal margin
→ Evidence: TBD pending materials SOP review
- Why 5: Thermal margin sensitivity of paste Ag content not factored into incoming acceptance criteria
→ Incoming acceptance criteria for solder paste were not developed with explicit reference to oven thermal margin at high-thermal-mass locations — a latent vulnerability exposed when oven performance degrades
→ Evidence: TBD pending SOP and control plan review
Root Cause(s)
RC-A — Zone monitoring and oven verification protocol gap (Primary)
Mechanism: Zone 7 hardware degradation → sustained -4°C to -6°C undershoot → insufficient thermal energy at the QFN ground-pad via array during TAL → cold solder joints.
Verdict: PROBABLE. Advances to CONFIRMED when Raj Patel's product-specific KIC profile shows the QFN via-array on #1913 falls below 219°C (or achieves inadequate TAL) while the control oven (#1911 or #1912) holds above 219°C on the same board under the same profile.
RC-B — Paste incoming acceptance criteria gap (Contributing)
Mechanism: PST-26-0339 released without evaluation against process thermal margin → elevated liquidus (219°C) narrows the tolerance window at the via array → combined with RC-A's undershoot, crosses the cold-joint threshold.
Verdict: PROBABLE. Advances to CONFIRMED when Maria Sanchez confirms either (a) an internal Ag limit ≥3.0% existed and was not applied to PST-26-0339, or (b) no prior SAC305 lots ran below 3.0% Ag, establishing this lot as a novel uncontrolled condition.
Interaction mechanism: Neither condition alone crosses the defect threshold. #1911/#1912 ran the same paste at 0.3% defects (RC-B alone is insufficient). Zone 7 drifted 2–3 days before defects appeared (RC-A alone did not immediately produce defects). Together — degraded oven + narrowed-margin paste — the via-array temperature crossed below the effective liquidus on #1913 specifically.
Ruled-Out Hypotheses
- Paste lot PST-26-0339 as a standalone root cause (the CAPA owner's original working theory) — RULED OUT as a standalone explanation. Evidence: Maria Sanchez's traceability data shows the lot was distributed nearly evenly across all three ovens (~500 boards each), yet #1911 and #1912 held at 0.3% defects while #1913 alone reached 4.2%. If the paste lot were sufficient on its own, elevated defects would be expected across all three ovens. The paste lot is retained in the causal model only as a contributing/enabling condition (RC-B), not a standalone cause.
- Process recipe or reflow profile change on #1913 — RULED OUT. No documented process changes exist on record since the April 28, 2026 KIC verification.
- Stencil wear — RULED OUT. No wear issues flagged during the investigation period.
- Board design or component variation across ovens — RULED OUT. Same board design, same stencil, same placement, and same components confirmed running across all three ovens per Maria's board PN traceability.
Escape Point
EP-1 — Zone 7 deviation alerting (associated with RC-A)
What should have happened: an automated alert on sustained zone deviation beginning May 29/30, escalated to maintenance.
What actually happened: no alert was generated or escalated; Raj Patel noticed the drift manually approximately the week of June 1 — roughly 3 days after onset.
Verdict: PROBABLE. The absence of a triggered/escalated alert is established by Raj's own account of manual discovery, but whether an alarm exists at all, exists but was misconfigured, or exists and fired without escalation is still TBD pending Raj's alarm-configuration check. This determines whether the gap is a design gap (no alarm capability) or an operational gap (alarm ignored) — advances to CONFIRMED when that check returns.
EP-2 — Incoming paste inspection (associated with RC-B)
What should have happened: Ag content on the PST-26-0339 COA evaluated against internal acceptance criteria before release to the line.
What actually happened: the lot was released to the line June 1; whether Ag content was checked against internal limits at all is currently unknown.
Verdict: LEADING. This is the least-evidenced escape point in the record — it rests entirely on inference (a COA deviation exists, and the lot reached the line) rather than a direct account of the inspection event itself. Advances to PROBABLE or CONFIRMED only after Maria Sanchez's SOP and receiving-log review.
EP-3 — In-process inspection, June 2–4 (independent of root cause)
What should have happened: X-ray or equivalent subsurface inspection capable of detecting cold joints at the QFN via array.
What actually happened: AOI + visual inspection only was in use during June 2–4, per Dan Kim's direct report; this method cannot reliably detect subsurface via-array cold joints. 127 boards were produced and moved to staging under this inspection regime.
Verdict: CONFIRMED. This is directly established by Dan Kim's stated inspection-method timeline (100% X-ray began June 5, the day after the NCR opened; AOI + visual sampling only before that) — this finding does not depend on any pending item and holds regardless of how RC-A/RC-B resolve.
Cause Completeness: Occurrence = RC-A and RC-B above. Detection = EP-1, EP-2, EP-3 above.
- Systemic: The oven qualification system (gold-board KIC only, 90-day cadence, no product-specific thermal verification) and the incoming material acceptance system (criteria not tied to process thermal margin) are two independent control-system designs that both permitted an undetected equipment fault and an unevaluated material condition to reach production simultaneously. This is a broader control-plan design weakness, not limited to Oven #1913 or this specific paste lot.
- Organizational: None identified in this investigation, because no staffing, workload, competency, or scheduling-priority factor was raised or evidenced during the 6M scan or team discussion — Raj, Maria, Dan, and Linda's roles and involvement were reviewed and no gap of this type surfaced. This is not independently verified as absent; it reflects that the investigation did not surface such a factor, not that one was actively ruled out.
Evidence
- Zone 7 thermocouple trend logs, Oven #1913, April 28 – June 10, 2026 (Raj Patel) — drift onset and magnitude
- Product-specific KIC profile run, #1913 vs. control oven (Raj Patel) — pending, decisive for RC-A
- Supplier COA, paste lot PST-26-0339 (Ag 2.8%, liquidus 219°C)
- Paste lot distribution traceability across Ovens #1911/#1912/#1913, June 1–10, 2026 (Maria Sanchez)
- Board PN / assembly confirmation across all three ovens (Maria Sanchez)
- Last KIC gold-board profile verification record, Oven #1913, April 28, 2026 — passed
- SPI paste volume data, ±10% of target across all three ovens
- Work Order WO-26-0610 — new stencil-printer squeegee installed May 30, 2026
- Dan Kim's inspection-method timeline: AOI + visual sampling June 2–4; 100% X-ray began June 5, 2026
- Dan Kim's 100% X-ray results on 127 boards from June 2–4 — pending, due for containment/customer notification
- Incoming QC procedure / paste acceptance criteria — pending, Maria Sanchez
- SAC305 paste lot history, prior 12 months — pending, Maria Sanchez
- SPI height-map capability and data — pending, Dan Kim / SPI system owner
- Oven make/model/control system confirmation across #1913/#1911/#1912 — pending, Raj Patel
Corrective Action
Verification actions (not corrective) — required because neither RC-A nor RC-B currently carries a CONFIRMED verdict; these actions confirm or refute a suspected cause and are tracked separately from corrective action:
- Product-specific KIC profile run, #1913 vs. control oven (Raj Patel) — confirms/refutes RC-A mechanism
- Zone 7 drift cause diagnosis — heater element / thermocouple / control card (Raj Patel)
- Alarm configuration diagnostic on #1913 (Raj Patel) — determines whether EP-1 is a design gap or operational gap
- Incoming QC procedure and paste acceptance criteria review (Maria Sanchez) — confirms/refutes RC-B mechanism and determines corrective action type
- SAC305 paste lot history, prior 12 months (Maria Sanchez) — determines RC-B weight
- Prior paste lot comparative profile run, if in-date inventory exists (Raj Patel + Maria Sanchez) — converts RC-A/RC-B interaction from inference to direct observation
- SPI height-map data pull re: squeegee change WO-26-0610 (Dan Kim / SPI operator)
- QFN-48 component lot / moisture / bake status review (Maria Sanchez)
- Oven make/model/control system confirmation across all three ovens (Raj Patel)
| # | Action | Addresses (RC / escape) | Owner (named) | Target Date | Verification Method |
|---|---|---|---|---|---|
| CA-1 | Take Oven #1913 offline; diagnose and repair the Zone 7 fault to restore zone temperature within ±1°C of setpoint | Confirmed Zone 7 out-of-spec condition (RC-A precursor fact) | Raj Patel | Within 48 hours of CAPA issue (by June 12, 2026) | Post-repair thermocouple reading confirms Zone 7 within ±1°C of setpoint, sustained over one full production shift |
| CA-2 | Configure zone temperature deviation alarms on Oven #1913's control system, with escalation to a named recipient | EP-1 (confirmed: no alert generated or escalated for the observed deviation) | Raj Patel | Within 5 days of CAPA issue (by June 15, 2026) | Alarm function test — simulate a zone deviation, confirm alert generates and escalates; threshold settings documented in maintenance record |
| CA-3 | Quarantine and disposition remaining PST-26-0339 reels — hold from production, notify supplier, determine return/destroy/conditional-use disposition | Confirmed material deviation from internal 3.0% Ag target (RC-B precursor fact) | Maria Sanchez | Immediate (June 10, 2026) | Written quarantine tag on all reels; supplier notification and disposition decision documented before any reel is released |
| CA-4 | Establish standing 100% X-ray (or equivalent subsurface inspection) coverage for QFN-48 ground-pad via array joints, replacing AOI-only coverage for this failure mode | EP-3 (confirmed detection gap — independent of RC verdicts) | Dan Kim (execution); Anna (procedure owner) | Within 5 business days (by June 17, 2026) | Updated inspection procedure documented and approved; inspection records show 100% X-ray coverage on all subsequent QFN-48 production |
| CA-5 | Update oven qualification SOP to require product-specific thermal profiling (minimum: QFN ground-pad via array on actual production PCBA) in addition to gold-board KIC, at initial qualification and post-maintenance re-qualification | RC-A systemic gap / EP-1 | Anna | SOP draft within 10 business days (by June 24, 2026) | SOP reviewed and approved per document control; first implementation executed as part of CA-1 post-repair verification |
| CA-6 | Update incoming solder paste acceptance criteria to include a process-capability-based Ag floor (candidate: ≥3.0%) referenced explicitly to worst-case oven thermal margin at high-thermal-mass joint locations; update receiving procedure to require COA review against these criteria before release | RC-B systemic gap / EP-2 | Maria Sanchez (criteria owner); Anna (process validation) | SOP draft within 10 business days (by June 24, 2026); implemented and trained within 15 business days (by July 1, 2026) | SOP reviewed and approved per document control; incoming inspection records for the next 3 paste lot receipts demonstrate COA review against the updated criteria |
Preventive Action
Scope: the same failure mode — an undetected zone-temperature drift combined with a marginal incoming material — could recur on Ovens #1911 or #1912, or on any other reflow equipment in the facility running high-thermal-mass assemblies.
| # | Preventive Action | Scope | Owner | Target Date | Verification Method |
|---|---|---|---|---|---|
| PA-1 | Assess zone-deviation alarm capability on Ovens #1911 and #1912; if same make/model/control system as #1913, configure identical alarm thresholds concurrently with CA-2; if different, conduct individual capability assessment | #1911, #1912, and any other reflow ovens in the facility | Raj Patel | Within 5 days of CAPA issue (by June 15, 2026) | Alarm function test on each oven; threshold settings documented per unit in maintenance records |
| PA-2 | Conduct a product-specific KIC profile baseline on Ovens #1911 and #1912 using the protocol established in CA-5, to document current via-array performance as a forward baseline | #1911, #1912 | Raj Patel | Within 10 business days (by June 24, 2026) | Profile results documented and retained; any underperformance found triggers immediate maintenance review |
| PA-3 | Apply the updated paste acceptance criteria (CA-6) to all future SAC305 receipts across all product lines and ovens, not limited to this product or Oven #1913 | All SAC305 paste procurement, facility-wide | Maria Sanchez | Concurrent with CA-6 (by July 1, 2026) | Incoming inspection records for all post-implementation paste receipts show COA review against the updated criteria |
| PA-4 | Review incoming acceptance criteria for other thermally sensitive materials (flux, other solder alloys) to determine whether similar process-capability-based limits are needed | All thermally sensitive incoming materials | Maria Sanchez | Within 20 business days (by July 8, 2026) | Review documented; any resulting SOP updates completed and approved per document control |
Effectiveness Verification
Metric: Cold solder joint defect rate on QFN-48 packages from Oven #1913, measured by 100% X-ray inspection.
Baseline: 0.3% (historical #1913 rate pre-June 2, 2026; concurrent #1911/#1912 rate during the defect window).
Acceptance threshold: ≤0.5% cold-joint defect rate across the full post-repair sample.
Minimum sample (as stated by the CAPA owner): ≥2,000 QFN-48 joints inspected by 100% X-ray on #1913 post-repair AND ≥10 production days — whichever takes longer to satisfy.
Early warning trigger: any single production day exceeding 1.0% — pause production on #1913 and investigate before continuing the verification run.
Secondary gate: zero customer complaints on product shipped from #1913 during the verification window.
Check schedule:
| Checkpoint | Timing | Action |
|---|---|---|
| 30-day check | ~July 10, 2026 | Dan Kim reports cumulative defect rate to Anna; continue if no early-warning trigger and rate tracking ≤0.5% |
| 60-day check | ~August 10, 2026 | If minimum sample (2,000 joints, 10 days) is met and rate ≤0.5%, Anna may declare effectiveness verified |
| 90-day check | ~September 10, 2026 | Final effectiveness confirmation if not already declared |
Reporting owner: Dan Kim — daily defect-rate tracking, weekly summary to Anna.
Closure authority: Anna — declares effectiveness verified or triggers secondary investigation.
Closure Criteria
This CAPA may be closed when ALL of the following are true:
1. Zone 7 hardware fault on #1913 diagnosed, repaired, and documented (Raj Patel)
2. Product-specific KIC profile on #1913 post-repair confirms via-array achieves ≥219°C with adequate TAL, on file
3. Zone-deviation alarms configured and function-tested on #1913 (and #1911/#1912 per PA-1)
4. Oven qualification SOP updated to require product-specific profiling — approved per document control
5. Incoming paste acceptance criteria updated with a process-capability-based Ag floor — approved per document control, applied to ≥3 subsequent paste lot receipts
6. PST-26-0339 disposition complete — quarantine resolved, supplier notification documented
7. Effectiveness verification criteria met: ≥2,000 joints, ≥10 production days, ≤0.5% defect rate, zero customer complaints during the verification window
8. All items in Open Items & Gap Impact below are resolved or formally accepted as residual risk by the Quality Manager
9. Quality Manager sign-off recorded
Open Items & Gap Impact
| # | Gap | Why Open | Impact |
|---|---|---|---|
| 1 | Product-specific KIC profile results (Raj Patel) | Pending; expected end of shift June 10 or early June 11 | Decisive for RC-A. Confirms or refutes the via-array thermal mechanism; if via-array temps prove equivalent across ovens, RC-A's primacy must be reexamined |
| 2 | Zone 7 drift root-cause diagnosis (Raj Patel) | Component not yet identified | Determines CA-1 specificity; if cause is a setpoint/config change rather than hardware, the Man/Method branch reopens |
| 3 | Alarm configuration status on #1913 (Raj Patel) | Whether alarms exist, thresholds, and whether one fired May 29/30 is unknown | Determines whether EP-1 is a design gap or an operational (escalation) gap — changes CA-2 scope and accountability |
| 4 | Oven make/model/control system across #1911, #1912, #1913 (Raj Patel) | Not yet confirmed | Determines PA-1 scope and timeline; does not affect RC-A verdict |
| 5 | Incoming QC procedure / Ag acceptance criteria (Maria Sanchez) | SOP not yet reviewed | Decisive for RC-B corrective action type — execution failure vs. criteria design gap; changes CA-6's specific content |
| 6 | SAC305 paste lot history, 12 months (Maria Sanchez) | Not yet pulled | Decisive for RC-B weight — novel condition vs. latent vulnerability exposed by the oven fault |
| 7 | Prior paste lot comparative profile run (Raj Patel + Maria Sanchez) | Requires identifying and locating in-date prior-lot inventory | High-value: would convert the RC-A/RC-B interaction from inference to direct observation if performed |
| 8 | SPI height-map capability and data re: squeegee WO-26-0610 (Dan Kim / SPI owner) | Not yet checked | If height maps show a via-array deposition change post-squeegee-install, reopens the Method branch as a third contributing factor |
| 9 | QFN-48 component lot / moisture / bake status (Maria Sanchez) | Not yet reviewed | If a new lot with inadequate bake coincided with June 1, reframes the interaction as three-factor rather than two |
| 10 | PST-26-0339 receiving/inspection date (Maria Sanchez) | Not yet pulled | Establishes exact EP-2 timeline; does not change the EP-2 finding but sharpens the narrative |
| 11 | Dan Kim's 100% X-ray results on the 127 held boards | Expected end of shift June 10 | Determines the content of customer notification to Midwest Industrial Controls — confirmed defects vs. precautionary hold cleared |
| 12 | Dan Kim's component-type defect breakdown from existing X-ray data | Not yet pulled | Refines whether the failure is QFN-48-specific (thermal-mass-driven) or broader (systemic undershoot); affects rework scope, not RC verdict |
| 13 | Physical oven floor layout (Anna / Linda Chen) | Not yet confirmed | Low-probability environmental variable; needed to formally close the Mother Nature branch |
| 14 | Reflow profile comparison across ovens — identical setpoints or legacy difference (Raj Patel) | Not yet pulled | If #1913 was configured with less margin by design, adds a Method finding and a profile-standardization action not currently in this record |