Scope & Deliverables

This page standardizes production isolation testing and the documentation evidence chain required for audits, customer safety reviews, and field disputes. It is written to prevent scope creep and to keep each topic inside its proper subpage.

Deliverables (What this page produces)

Each deliverable below is defined as a hand-off artifact that can be used in production, supplier quality, and audit workflows without re-interpretation.

Typical Use Cases (Disputes this page closes)

• Supplier / factory audit: “Where is the evidence, and can a shipped lot be traced to it in minutes?”
• Customer safety review: “Reinforced isolation is claimed—what documents prove it under the stated conditions?”
• Regulatory compliance check: “Why are parameters set this way, and what is the retest policy?”
• Field rework dispute: “Production Hi-pot fails—does it implicate the DUT, or the fixture/environment first?”

Hard Boundary (Not covered on this page)

The topics below are intentionally excluded to avoid overlap with sibling pages. Only brief references are allowed.

Diagram · Evidence Chain Map (Traceability Spine)

The diagram summarizes how production tests and documents form an audit-grade evidence chain, anchored by lot-level traceability.

Vocabulary & Test Taxonomy

Terminology alignment prevents false conclusions and mismatched acceptance criteria. The definitions below standardize what each test stresses, what it detects, what it does not prove, and how it is commonly misused in audits and production lines.

Core Tests: What They Stress vs What They Prove

This comparison is written to eliminate three common failures: (1) using the wrong test for a claim, (2) assigning lifetime meaning to a short-duration screen, and (3) accepting a report without normalized conditions.

Test Taxonomy: Who Owns Which Evidence

Many audit failures are not technical failures—they are ownership failures. Each test layer below is mapped to the party that typically owns the evidence and the artifacts that should be expected.

Myth vs Reality (Preventing Misuse)

Diagram · Test Taxonomy Tree (Layer + Owner + Artifact)

The diagram organizes testing into qualification, production screening, and monitoring. Each layer is labeled with ownership and expected evidence.

Standards & Certificate Landscape

Vendor claims are accepted only when they map to auditable evidence. This section explains how to read datasheet statements without copying standard text—focusing on evidence shape, where key fields appear, and validity and scope limits.

How to Read Datasheet Claims (3-step Method)

• Step 1 — Identify the claim type: insulation class (basic/reinforced), working voltage (VIORM/VIOTM), PD evidence, or certification wording.
• Step 2 — Demand the correct evidence shape: certificate, CB report, test report, and/or production test record (depending on claim).
• Step 3 — Validate conditions and scope: pollution degree, altitude, temperature class, package/material/site scope, and report revision.

Evidence Shape Differences (What to Request)

The items below are listed only to guide evidence requests and reading patterns. The goal is to know which document to ask for and what section to locate.

• UL 1577: typically supports dielectric withstand claims with certificate-style evidence; focus on scope and ratings tables.
• VDE 0884-11: often provides structured insulation coordination evidence; focus on working voltage terms and conditions/limitations.
• IEC 62368-1: system safety framework that may drive CB reporting; focus on CB report sections and applicability notes.
• IEC 60601-1: medical safety; frequently tight on leakage and documentation rigor; focus on conditions and evidence completeness.
• IEC 61010: test/measurement/control equipment; evidence is often presented in report form; focus on rated conditions and limitations.

Where to Find VIORM / VIOTM / Working Voltage Evidence

Working-voltage terms are meaningful only when tied to document location and a condition set. The table below standardizes what must be checked.

Certificate Validity Checklist (Revision · Conditions · Scope)

• Revision: standard edition, document version, and certificate/report revision match the referenced claim.
• Conditions: pollution degree, altitude/derating, temperature class, and stated test conditions are consistent with intended use.
• Scope: part family, package, molding/material/process, and manufacturing site coverage match the shipped hardware; PCN history is included.

Diagram · Claim → Evidence Mapping

The diagram maps common datasheet claims to evidence document types and the report sections where the verifying fields typically live.

Hi-Pot / DWV Fundamentals

Hi-pot (dielectric withstand) is a short-duration stress screen across the isolation barrier. It is powerful for catching gross weaknesses, but it can also generate false fails when the test chain, environment, and parameters are not controlled.

AC vs DC Hi-Pot (Why Trip Behavior Differs)

AC and DC hi-pot can produce different outcomes on the same hardware because the measured current is composed of different dominant parts. The table below focuses on interpretation, not on fixed numeric settings.

Ramp · Dwell · Trip (Parameter Logic for Production)

The three parameters below shape both yield and defect detection. The objective is to (1) avoid killing good parts via measurement artifacts, and (2) preserve sensitivity to real leakage and surface discharge paths.

False-Fail Sources (Fast Isolation Before Blaming the DUT)

Most production hi-pot escalations start as fixture/environment problems. A fast isolation approach prevents incorrect disposition and unnecessary rework.

High-Voltage Safety & SOP (Minimum Requirements)

Hi-pot testing must be executed as a controlled process. The minimum set below is written for production readiness and audit defensibility.

• Interlocks & enclosure: guarded fixtures, interlock switches, and controlled access during HV enable.
• Discharge path: defined discharge hardware and verification steps before handling any DUT/fixture.
• Operator control: authorization, training records, and PPE policies appropriate to the HV system.
• Calibration chain: calibration reference for the tester and a daily/shift self-check log.
• Stop-and-isolate rules: containment workflow for spikes in fail rate; prevent “retest until pass” behavior.

Diagram · Hi-Pot Equivalent Model (Cbar + Rleak + Trip Path)

The diagram shows the measurement chain and the dominant current paths that drive trip behavior, including fixture leakage paths that cause false fails.

Hi-Pot in Production

Production DWV must balance yield, cycle time, and risk containment. This section standardizes when to run 100% vs sampling, how to convert type-test evidence into production settings (guardband), and how to prevent “retest-to-pass” behavior while maintaining audit-grade traceability.

100% vs Sampling (Decision Matrix)

The choice between 100% screen and sampling should be justified by consequence and evidence strength—not by habit. The decision below is designed to be defensible in audits and customer safety reviews.

Guardband (Type Evidence → Production Settings)

A production DWV setting is not a single voltage number. It is a controlled parameter pack that translates qualification evidence into a repeatable production screen while avoiding unnecessary overstress.

Retest Policy (Prevent “Retest-to-Pass”)

Retest exists to isolate fixture and environment effects—not to erase a failure. The policy below is structured for audit defensibility and consistent disposition.

Production Records (Minimum Field Set)

Records must support rapid traceability from a shipped lot back to the exact test chain and settings revision. The field set below is designed for MES/station logs and audit evidence packs.

• Traceability: lot/date code, unit ID (if applicable), work order, station ID.
• Test chain: tester asset ID, calibration reference, fixture ID/revision, cable ID.
• Parameter pack: AC/DC mode, ramp, dwell, trip, measurement window, filter/window settings, pack revision.
• Environment: temperature, relative humidity, altitude category (if tracked), gate pass/fail.
• Accountability: operator/shift, exception code, retest count, disposition category.

Audit Q&A (Why This Value and This Policy)

These answers are written as consistent audit language to explain screening strategy and parameter choices without invoking standard text.

Diagram · Production DWV Flow (Setup → Test → Fail Branch → Disposition)

The flow below is written as a production-ready evidence chain: setup verification and environment gates precede testing, and the failure path is controlled to prevent retest abuse.

Partial Discharge Basics

Partial discharge (PD) evidence indicates early discharge activity under defined conditions. It is not the same as breakdown. This section focuses on how to interpret PDIV/PDEV, what fields must be normalized to compare results, and how to handle lab-to-lab variation without losing evidence integrity.

PDIV / PDEV (Report Reading, Not Physics)

• PDIV: the voltage level where detectable discharge activity starts under the stated detection threshold and noise floor.
• PDEV: the voltage level where discharge activity disappears when voltage is reduced, often showing hysteresis under the stated conditions.
• Apparent charge: a measurement-chain quantity; interpretation requires the coupling network and detector settings.

What Moves PD Numbers (Condition Sensitivity)

PD outcomes change with materials, environment, excitation, and the measurement chain. Comparisons are valid only after normalization.

Why Two Labs Disagree (Normalization Checklist)

Lab-to-lab differences are often caused by setup and threshold mismatches rather than by hardware changes. The table below standardizes what must be normalized before declaring a disagreement meaningful.

How PD Evidence Enters the Evidence Pack

• Document control: report ID, revision, issuing lab, and standard reference fields.
• Condition set: excitation + measurement chain + environment captured as explicit fields.
• Claim mapping: which datasheet claim the PD evidence supports and under what stated conditions.
• Traceability: part family/package/material/site scope and linkage to lot or qualification batch.
• Change triggers: PCN/material/site changes that require PD re-evidence under the same normalized condition set.

Diagram · PD Measurement Chain (Source → Coupling → Detector → DUT)

The diagram highlights the measurement chain and control points (noise and calibration injection) that drive PD comparability.

PD in Reality

Partial discharge becomes valuable only when it is written as a requirement, supported by the right evidence, and verified by a repeatable acceptance rule. This section converts PD into purchase-ready clauses and review language, and keeps PD and DWV in their correct complementary roles.

When PD Evidence Is Typically Required

PD evidence is most defensible when audits and claims demand proof of early discharge activity under controlled conditions. The triggers below are written as review-ready criteria rather than standard text.

How to Specify PD (Fields That Must Be Locked)

A PD requirement must lock a minimum set of fields to keep results comparable across labs and suppliers. The list below is the smallest set that prevents “non-comparable” disputes.

• Metrics: PDIV, PDEV, apparent charge (if reported), and pass rule.
• Excitation: waveform, frequency, ramp rate, dwell window, and test sequence.
• Measurement chain: coupling network (Cc), measuring impedance (Zm), detector bandwidth, gating method.
• Threshold controls: detection threshold and stated noise floor (or equivalent statement).
• Environment: temperature, relative humidity, and altitude category (or stated conditioning method).
• Statistics: sample size, lot/date code (or qualification batch), and part variant/package.
• Document control: report ID, revision, issuing lab, date, and scope limitations.

Requirement → Evidence → Acceptance (Review Logic)

A PD clause is closed only when evidence matches the stated condition set and the acceptance rule can be evaluated without assumptions.

Spec Template (Copy Into PRD / AVL)

The template below is written to be pasted directly into procurement documents and supplier qualification checklists. Replace bracketed terms with project-specific values.

Diagram · Requirement → Evidence → Acceptance

The diagram shows the three gates required to close a PD clause: the requirement definition, evidence completeness, and acceptance evaluation.

CTI & Material Evidence

CTI is often treated as a number, but audits treat it as a documentation and process control problem. This section organizes where CTI evidence lives, how it is tied to real production materials and processes, and how to answer common audit questions without drifting into creepage geometry rules.

CTI in One Page (Evidence View)

• What CTI represents: a material classification input used in surface tracking risk discussions and documentation.
• Where it appears: laminate/material documents, PCB selection records, and pollution-related audit conversations.
• What matters for reviews: the evidence scope (material, supplier, revision) and its linkage to production usage.

Where CTI Evidence Lives (Minimum Document Set)

Evidence should cover materials and the processes that keep the surface condition stable in production. The list below is structured as an evidence pack index.

Common Audit Questions (Answer Skeletons)

The questions below reflect how audits probe CTI-related evidence. Each answer should point to a controlled document, a record field, and a change trigger.

Evidence Pack Checklist (Folder-Ready Index)

• Materials/PCB-Laminate: laminate evidence, CTI field, document ID/rev, approved grade list.
• Materials/Coating: coating material IDs, coverage definition, cure window, inspection records.
• Process/Cleanliness: cleaning spec, sampling plan, measurement method, pass rule, exceptions.
• Process/Records: receiving traceability, batch linkage fields, out-of-control containment.
• Change-Control/PCN: trigger list, re-review scope, approvals, revision history.

Diagram · Material → Process → Risk

The diagram frames CTI as a documentation chain that connects materials and process controls to surface tracking risk and audit questions.

Test Setup & Fixture Engineering

In production isolation testing, the most expensive failures are often false fails caused by fixtures, contamination, cabling leakage paths, missing self-checks, or uncontrolled environment. This section turns setup engineering into repeatable controls that protect takt time, yield, and audit defensibility.

Fixture Basic Requirements (Design and Verification)

A production fixture must enforce consistent geometry, controlled insulation surfaces, and a predictable discharge path, while preventing operator exposure to hazardous voltage.

Cables & Connections (Leakage Path Control)

Cabling and connectors frequently form unintentional leakage paths. Control is achieved by routing discipline, consistent shielding strategy, and a defined cleaning and fastening routine.

• HV lead routing: keep leads away from grounded metal edges, sharp corners, and parallel proximity to sensitive wiring.
• Shield strategy: document the shield termination method and keep it consistent across stations and shifts.
• Connector integrity: define fastening torque and strain relief; prevent looseness-induced micro-arcing.
• Clean surfaces: schedule cleaning of sockets, guards, and cable ends; track frequency and exceptions.

Calibration & Shift Self-Check (Minimum Set)

Self-check is not a yield tool. It is a data-validity gate that makes results defensible. The minimum set below is designed for every shift.

Environmental Gates (Humidity, Dust, Ionic Contamination)

Environment turns surface leakage and discharge into a random variable. Production testing requires defined gates and exception handling.

• Humidity: treat RH as a gate variable; define action when RH exceeds the allowed window.
• Dust control: enclosure and cleaning prevent conductive films that cause intermittent surface discharge.
• Ionic contamination: process control and periodic verification prevent silent leakage escalation.
• Environment records: log temperature/RH and link to batch records for traceability.

False Fail Triage (Containment Without “Re-test to Pass”)

A controlled triage sequence prevents costly scrap and prevents “re-test to pass” behavior that destroys audit credibility.

Diagram · Fixture Block Diagram

The block diagram shows where false fails originate: HV routing, enclosure safety, socket surfaces, and the discharge and verification path.

Documentation Pack

A production-ready evidence pack is not a document pile. It is a version-controlled archive that links claims to reports, makes key fields easy to retrieve, and answers audit questions in minutes. This section defines what to request, what to archive, and how to structure evidence for traceability and change control.

Must-Have Documents (Audit-Defensible Minimum)

• Certificates: certificate ID, revision, validity window, scope and limitations.
• CB report / test report: report ID, revision, key sections that support insulation claims and conditions.
• Traceability: device family, part number, package/variant, lot/date code linkage, test station records.
• PCN/PDN policy: change triggers, notification timing, re-evidence rules, superseded document handling.

Optional Documents (High Value for Fast Reviews)

• Process control summaries: station self-check policy, environment gates, containment rules.
• Incoming inspection: receiving checks and acceptance criteria for critical variants.
• Storage and handling spec: moisture and contamination controls for sockets, fixtures, and sensitive materials.
• SOP excerpts: operator steps for discharge verification and exception handling.

Evidence Pack Table (What to Request and Where to Find Key Fields)

This table converts audit requirements into a retrieval index. It clarifies who issues each document, how long it is valid, and where key fields typically appear in the document.

Archiving Rules (Structure and Version Control)

• Indexing: Device family → Part number → Revision → Validity window → Conditions and scope.
• Mandatory metadata: source, date, doc ID, revision, scope, superseded-by reference.
• One-page summary: maintain a summary sheet per part/variant to list extracted key fields and where they came from.
• Superseded handling: keep older documents read-only with explicit superseded markers and replacement links.

What Auditors Ask (Fast Retrieval Targets)

• Which report section supports the insulation claim and under what conditions?
• What is the document revision and validity window, and what is explicitly excluded?
• Does the report scope cover the package/material/site used in production?
• Where are PD conditions and thresholds stated, and are they comparable across evidence?
• Where is production screening policy (100% vs sampling) documented, including retest containment?
• What are PCN triggers and how do they force re-evidence and re-approval?
• Can a specific field return be traced to a lot/date code and a station program revision?
• How is superseded evidence prevented from being used for new builds?

Diagram · Doc Pack Folder Map

The folder map shows an archive structure that scales with part families, controls revisions, and keeps auditors focused on the right evidence.