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6.19 Critical Terminology for Manufacturing Process Control

LanguageThe onsuccessful theexecution factoryof floorhigh-reliability manufacturing requires a mandatory, shared lexicon that transcends department-specific jargon. Misinterpretation of key terms, acronyms, and metrics is a mixdirect contributor to process variability and systemic non-conformance risk. This standardized glossary provides concise, objective definitions for the terminology critical to managing yield, quality metrics, and regulatory compliance, ensuring all engineering and management functions operate from a single, auditable set of formaldefinitions.

standards,

6.19.1 acronyms,Standardized Acronyms and shorthandTechnical slang,Glossary

and

Definitions misunderstandingprovide itthe cancritical create costly mistakes. A shared glossary keeps teams aligned by turning jargon into clear meaning,context linking shopshop-floor talk backactivities to specifications,documented andengineering pointing to the standards that govern decisions. With quick cross-references, it becomes easier to navigate the web of terms that tie design, process, and inspection together.

B.1 How to read this

specifications.

  • Bold = acronym/term. Super short, plain-English definitions.
  • See also → points to related entries so you can jump around.
  • If a term is process-or class-specific, we note it (e.g., IPC Class 2/3, SMT, THT).



B.2 A–Z glossary

Term

Meaning (plain and quick)

See also →

A-610 (IPC-A-610):

Visual The definitive standard governing the visual acceptability standardcriteria for electronic assemblies (yourworkmanship day-to-day “is this OK?” book)standard).

  • J-STD-001AOI:, 7711/7721, Class

    • ACL (Airflow/Current Limit)

    In burn-in, guard bands for fan speed or current so trends don’t drift into failure.

    Burn-in, Guard band

    AQL

    “Acceptable Quality Level.” Sampling intensity for incoming or in-process inspection.

    Sampling plan, SQE

    AOI

    Automated Optical Inspection ofsystem solder/placement usingutilizing cameras and rules/ML.algorithms for surface mount solder joint and component placement verification.

  • SPIAQL:, AXIAcceptable Quality Level

    • . A statistical metric defining the maximum number of defectives permitted in a AXIsampling plan

     for a lot to be considered acceptable.

  • AXI: Automated X-ray Inspection. (2D/3D/laminography)Non-destructive testing method for inspecting hidden solder joints (BGA/QFN).

    • AOIBGA, QFN) and verifying internal layer registration.

  • AVL:, BGA

    • AVL

    Approved Vendor List. The mandatory registry of qualified suppliers for parts/materials you’reand allowedcomponents. toProcurement buy.

    outside this list is prohibited.

  • SCARBGA:, PPAP, Procurement

    • BGA

    Ball Grid Array. A high-density component package withdefined by an array of hidden solder ballsspheres underbeneath the part.

    device body.

  • AXIBOM:, Head-in-pillow

    • BIB (Burn-in Board)

    Fixture that lets multiple units run in a chamber during burn-in.

    Burn-in, Rack

    BOM

    Bill of Materials—whatMaterials. goesThe intocomplete, controlled list of raw materials, parts, and quantities required for product assembly.

  • CAPA: Corrective and Preventive Action. The formal, mandated process to identify, contain, and eliminate the product (PN, qty, AVL).

    • MBOM, Kitting

    Boundary Scan (BSCAN/JTAG)

    Test method using scan chains to toggle/observe pins and program devices.

    ICT, DFT

    Bow/warp

    PCB flatness errors thatroot cause placement/reflow and fit issues.

    Panelization, Standoffs

    CAPA

    Corrective/Preventive Action—formal fix to stop recurrence.

    SCAR, ECN, Root cause

    CoC / CoA

    Certificate of Conformancesystemic / Analysis from supplier proving spec compliance.non-conformance.

    Incoming, SQE

  • Class (1/2/3):

    •  IPC Workmanship Class. The classification that dictates the level of workmanship class;quality most EMS shipsrequired. Class 2; is standard; Class 3 is mandatory for critical, high-reliability.reliability applications.

    A-610, J-STD-001

  • CMC / CpkCpk: / Cp

    • Capability metrics;Metrics. Statistical indices measuring how tighttightly and centered a process runsoperates vsrelative spec.to specification limits.

    Mandatory for Statistical Process Control (SPC).

  • CTQ:, PpkCritical-to-Quality. Any design or process requirement that directly impacts performance or reliability and must be controlled and measured.
  • CTE:, Window

    • Conformal coat (CC-830)

    Protective coating over assemblies; keep out of connectors/keepouts.

    Masking, Potting

    CPA / TPA

    Connector Position Assurance / Terminal Position Assurance—plastic locks that ensure full mate.

    Mating sequence, Tug test

    CTE

    Coefficient of Thermal Expansion—mismatch drives solder/mechanical stress.

    WarpageExpansion,. The rate at which material dimensions change with temperature. Mismatches drive Reliability

    CTQ

    Critical-to-Qualitysolder requirementjoint you must control/measure.

    Control planstress, and warpage.

  • DFx: FMEA

    • DFM / DFA / DFT / DFx

    Design for Manufacturability/Assembly/Test—X. An encompassing set of engineering rules that(e.g., raiseManufacturability, Assembly, Test) implemented to optimize design for high yield and coverage.

    3.1,low GoldenCost packof Poor Quality (COPQ)

    .

  • DPMO / PPMPPM:

    •  Defects per Million Opportunities / Parts Per Million—Million. Standardized metrics for quantifying defect metrics.rates and reporting process yield performance.

  • ECN / ECO: Engineering Change Notice / Order. The controlled document dictating and approving formal changes to a product design, BOM, or documentation.
  • EMC / EMI: Electromagnetic Compatibility / Interference. Control requirements that minimize noise generation and susceptibility. Often requires bonding to Protective Earth (PE).
  • ENIG / OSP / HASL: Common PCB finish types that define the surface's solderability and shelf life. Governed by J-STD-003.
  • ERP: Enterprise Resource Planning. The system managing core business processes, including procurement, inventory, and materials planning. Integrates with MES.
  • ESD (S20.20): Electrostatic Discharge. The mandatory control program covering zones, grounding, personnel protective equipment, and audit standards.
  • FPY: First Pass Yield. The percentage of units successfully passing a specific manufacturing or test stage the first time. A key Key Performance Indicator (KPI).
  • Gage R&R: Gage Repeatability and Reproducibility. A study within MSA to quantify the variation contributed by the measurement system itself.
  • Golden board/unit: The known-good reference sample used for fixture teaching, system setup, and process debug validation.
  • Head-in-pillow: A BGA defect where the solder ball and solder paste fail to fully coalesce, forming a weak, unreliable joint. Requires AXI detection.
  • Hipot: High Potential Test. A high-voltage safety test verifying the integrity of dielectric withstand voltage and insulation resistance (IR).
  • ICT: In-Circuit Test. Automated electrical test utilizing a bed-of-nails fixture to measure components and net continuity on the PCB.
  • IPC-7711/7721: The standard governing rework, repair, and modification of electronic assemblies. Rework tickets must cite the specific method ID.
  • J-STD-001: The definitive standard governing the requirements for soldered electrical and electronic assemblies (process standard).
  • Kitting: The process of accurately pulling and preparing all required components from inventory per the BOM for a specific work order. Kitting error is a major defect risk.
  • Land pattern (IPC-7351): The standardized footprint geometry on the PCB pad designed to ensure optimal printing and reflow characteristics.
  • Lean / 5S: A manufacturing philosophy focused on waste reduction and continuous improvement, incorporating 5S (Sort, Set, Shine, Standardize, Sustain) for workplace organization.
  • MBB / HIC: Moisture Barrier Bag / Humidity Indicator Card. Required packaging for MSL components to prevent moisture absorption and subsequent defect risk during reflow.
  • MES: Manufacturing Execution System. The core system controlling and documenting the execution of production, tracing Work In Process (WIP), and managing serialization.
  • MSA: Measurement System Analysis. A required study to confirm the reliability and accuracy of measuring equipment.
  • MSL: Moisture Sensitivity Level. The component classification (J-STD-033) that defines mandatory floor life and baking protocols to prevent popcorning during thermal processing.
  • NCR: Non-Conformance Report. The formal document recording any material, component, or assembly found to be outside documented specifications.
  • NPI: New Product Introduction. The controlled phase that manages the transition from prototype build to volume production, including mandatory First Article Inspection (FAI).
  • OEE: Overall Equipment Effectiveness. The metric quantifying manufacturing efficiency: Availability x Performance x Quality.
  • Poka-yoke: Mistake-proofing. Design or fixturing solutions (e.g., keys, interlocks) implemented to make it physically or functionally impossible to perform an action incorrectly.
  • RCA: Root Cause Analysis. The systematic method used to determine the fundamental cause of a defect or failure, feeding directly into the CAPA process.
  • SCAR: Supplier Corrective Action Request. A formal, documented ticket issued to a supplier detailing a quality issue and mandating corrective action.
  • SIR: Surface Insulation Resistance. A test method (IPC-TM-650) used to assess the effectiveness of the cleaning process and potential risk of electrochemical migration.
  • SMT / THT: Surface-Mount Technology / Through-Hole Technology. The two fundamental methods of component assembly.
  • SPI: Solder Paste Inspection. A mandatory 3D volume measurement of printed paste applied to the board, performed before component placement.
  • SPC: Statistical Process Control. The systematic use of control charts and metrics (Cp, Cpk) to detect process drift and prevent non-conformance.
  • SWI: Standard Work Instruction. The documented, controlled procedures (often visual) providing step-by-step direction for a specific operation.
  • TAL: Time Above Liquidus. The portion of the reflow thermal profile where the solder is in its liquid state. Duration is a critical process variable.
  • TIM: Thermal Interface Material. Any material (e.g., pad, grease, paste) used to enhance thermal transfer between a heat-generating component and a sink.
  • Torque map: The controlled document specifying the mandatory torque setpoints (and threadlocker grade) for all fasteners on an assembly.
  • Traceability (IPC-1782): The mandatory capability to link a finished unit back to its constituent components, process steps, and test results via a database (MES).
  • Void (BGA/thermal): Gas pockets trapped within a solder joint. The maximum allowable void area is a critical acceptance criterion verified by AXI.
  • WIP: Work In Process. Units that have started production but are not yet complete, requiring continuous tracking by the MES.
  • WHMA-A-620: The acceptability standard for cable and wire harness assemblies.

    • Final Checklist

    Requirement Mandate

    YieldRelevant Standard / Metric,

    Key COPQEngineering Action Required

    DOEWorkmanship Audits

    IPC-A-610

    DesignVerify ofall Experiments—structureddefects testsare toclassified findby bestClass process1, window.2, or 3

    Process Control Verification

    WindowJ-STD-001

    Define finding,and monitor SPCTAL and reflow profile stability

    Defect Root Cause

    CAPA

    Mandatory formal action to prevent recurrence

    Material/Part Qualification

    AVL, PPAP

    Prohibit use of non-approved suppliers and materials

    Process Performance Reporting

    FPY, OEE, DPMO

    Utilize metrics to identify and prioritize bottleneck operations

    Measurement System Integrity

    MSA / Gage R&R

    Certify all gauges and test fixtures are trustworthy

    BGA Solder Joint Verification

    AXI / Voiding Limits

    Ensure X-ray criteria meet established void percentage limits

    Component Handling Control

    J-STD-033 / MSL

    Enforce Baking Protocols for floor-life expiration

    Documented Change Control

    ECN / ECO

    EngineeringTrack Change Notice/Order—controlledall design orand docprocess changes.

    Revision, Golden unit

    EMC / EMI

    Electromagnetic Compatibility / Interference—keep noise in/outchanges via grounding/shields.

    Shield clamp, Bond <0.1 Ω

    ENIG / OSP / ImmAg / ImmSn / HASL

    PCB finishes; affect solderability and shelf life.

    Finish, J-STD-003

    EOL / EOO

    End-of-Life / End-of-Order—lifecycle or last-time buy status.

    AVL, Procurement

    E-stop

    Emergency stop button on equipment/fixtures; must be reachable.

    Hipot cage, Interlock

    ERP

    Enterprise Resource Planning—materials, POs, inventory; pairs with MES.

    MES, Kitting

    ESD (S20.20)

    Electrostatic Discharge control program—zones, straps, floors, audits.

    Shielding bag, Pink bag

    F/G Terminals (Ring/Fork)

    Lugged terminations to studs; often earth (PE) points.

    Torque, <0.1 Ω

    FA / FAI

    First Article (Inspection)—first units built with deep checks; forms the reference.

    Golden unit, 27.3

    FCT

    Functional Test—power, signals, performance checks.

    ICT, Burn-in

    Fiducial

    Registration marks for machines (pick-and-place, AOI, stencil).

    Global/local fiducials

    FIFO

    First-In, First-Out—inventory handling to control age/shelf life.

    MSL, Shelf life

    FIPG

    Formed-in-Place Gasket (dispensed bead) for seals.

    Gasket, Compression %

    FPY

    First Pass Yield—percent passing a step the first time.

    Pareto, Rework

    FR-4 / Tg

    PCB laminate and its glass transition temperature; impacts warpage.

    Stackup, Reflow profile

    Gage R&R

    Measures measurement system variation (Repeatability & Reproducibility).

    MSA, SPC

    Golden board/unit

    Known-good reference sample used for teaching and debug.

    FAI pack, Libraries

    GS1 / QR / DataMatrix

    Barcode standards; 2D codes for SN/MAC/etc.

    Label map, Verifier grade

    Head-in-pillow

    BGA defect: ball and paste don’t fuse; looks “kissed” in X-ray.

    Voids, Profile

    Hermes / SMEMA

    Line-handshake standards for board transfer/connectivity.

    Buffers, Line control

    Hipot / IR

    Dielectric withstand high-voltage test / Insulation resistance.

    Safety test, Leakage

    Hot lot

    Priority lot that jumps the queue (customer or containment driven).

    Containment, Quarantine

    ICT

    In-Circuit Test via bed-of-nails; measures nets/components quickly.

    Boundary Scan, Fixture

    IMDS / RoHS / REACH

    Material declarations/regulatory constraints.

    Regulatory labels, Compliance

    IPC-2581 / ODB++ / Gerber

    PCB manufacturing data formats.

    Centroid, CAM

    IP (Ingress Protection)

    Dust/water rating (e.g., IP65, IP67); requires sealing proof.

    Gasket, Compression %

    J-STD-001/002/003/033/020

    Solder process; component/PCB solderability; moisture handling and reflow classification.

    A-610, MSL

    Kanban

    Pull-based replenishment signal (cards/bins).

    Supermarket, WIP

    Kitting

    Pulling the right parts per work order/variant; accuracy drives yield.

    AVL, Shortage

    Land pattern (IPC-7351)

    Footprint geometry for parts on the PCB.

    Aperture, Courtyard

    Lean / 5S / Visual Mgmt

    Organize to see problems: Sort, Set, Shine, Standardize, Sustain.

    Andon, Shadow board

    Lot

    Group of items produced together under common conditions.

    Traceability, IPC-1782

    MBOM / EBOM

    Manufacturing BOM (what you build with) / Engineering BOM (what is designed).

    BOM, PLM

    MBB / HIC

    Moisture Barrier Bag / Humidity Indicator Card for MSL parts.

    MSL, Dry cabinet

    MES

    Manufacturing Execution System—routes, WIP states, work records tied to SN.

    ERP, Traceability

    MOQ

    Minimum Order Quantity from a supplier.

    Procurement, AVL

    MOV / Y-cap

    Surge protector / EMI capacitor to earth; affect Hipot/leakage.

    Safety test, Trip

    MSA

    Measurement System Analysis—ensures your gauges are trustworthy.

    Gage R&R, SPC

    MSL

    Moisture Sensitivity Level for ICs; drives floor-life and baking.

    J-STD-033, Bake

    NCR

    Non-Conformance Report ticket; records defect outside spec.

    MRB, Disposition

    NIST traceable

    Calibration linked to national standards.

    Calibration, Certificate

    NPI

    New Product Introduction—prototype to pilot to volume transition.

    FAI, Golden

    NPTH / PTH

    Non-Plated / Plated Through Holes.

    Via-in-pad, Drill

    Nylock / Prevailing-torque

    Nuts with built-in friction to resist loosening.

    Threadlocker, Torque

    OEE

    Overall Equipment Effectiveness: Availability × Performance × Quality.

    SMED, Bottleneck

    ODB++

    Rich PCB data format; alternative to Gerber.

    IPC-2581

    OLP / OPL

    One-Point Lesson (single-page standard/learning with photo).

    Knowledge base, CAPA

    Open time (paste)

    Time solder paste remains printable after exposure.

    Stencil, SPI

    OSP

    Organic Solderability Preservative finish on PCBs.

    ENIG, HASL

    OTP / eFuses

    One-Time-Programmable bits; enable secure boot/locks.

    Provisioning, 25.3

    Pareto

    Bar chart ranking defect types by frequency or cost.

    27.1, Root cause

    PE (Protective Earth)

    Safety ground; must bond to accessible metal <0.1 Ω.

    Hipot, Earth bond

    Pigtail (shield)

    Short drain wire from shield; keep ≤10 mm when 360° clamp isn’t possible.

    Shield clamp, EMC

    PLM

    Product Lifecycle Management—source of drawings/CAD/specs.

    ECN, MBOM/EBOM

    PnP (Pick-and-Place)

    SMT placement machine.

    Feeders, Fiducials

    Poka-yoke

    Mistake-proofing (keys, guides, software interlocks).

    CPA/TPA, Fixtures

    PPAP

    Production Part Approval Process—supplier qualification package.

    FAIR, SCAR

    Ppk / Pp

    Long-term capability indices (include shifts); cousins of Cpk/Cp.

    SPC, Run chart

    PPM

    Parts Per Million (defects); see DPMO when counting opportunities.

    Yield

    Press-fit

    Pin insertion into plated holes without solder; force-displacement monitored.

    7711/7721, Acceptance

    PSA

    Pressure-Sensitive Adhesive for labels/gaskets.

    Label map, Dwell

    PTH

    Plated Through Hole—barrel has copper; used for THT and vias.

    THT, Via

    Quarantine (NG-QUAR)

    Physical/data state to isolate failed units/lots.

    Containment, MRB

    QBR

    Quarterly Business Review with supplier or design.

    Scorecard, SCAR

    QFN / QFP / SOT / LGA

    Common SMT packages with different lead styles.

    Land pattern, Reflow

    R&R (Rework & Repair)

    Fixing defects to bring within spec (7711/7721 methods).

    Rework ticket, Traveler

    RMA

    Return Material Authorization—customer return process.

    COPQ, Traceability

    ROSE / SIR

    Ionic cleanliness tests (residue level / insulation resistance over time).

    Cleaning, J-STD-001

    RoHS / WEEE

    EU environmental directives: hazardous substances / end-of-life recycling.

    Regulatory labels, IMDS

    Root cause

    The changeable reason a failure happened (Design/Supplier/Process).

    27.2, CAPA

    SCAR

    Supplier Corrective Action Request—formal ticket to supplier with proof and containment.

    SQE, PPAP

    Shielding bag (metal-in)

    ESD bag that forms a Faraday cage—not the pink bag.

    ESD, Pink bag

    Shortage

    Missing parts vs kit; drives substitutions or holds.

    Kitting, AVL

    Shrink (label)

    Heat applied to seat labels/gaskets per spec.

    Dwell, Roller

    SIR

    Surface Insulation Resistance test (post-cleanliness reliability).

    ROSE, CC-830

    SKU / Variant

    Specific sellable configuration; drives labels, tests, firmware.

    MES, Recipe

    SMED

    Single-Minute Exchange of Die—methods to slash changeover time.

    5S, OEE

    SMT / THT

    Surface-Mount / Through-Hole Technology assembly processes.

    Reflow, Wave, Selective

    Solderability (J-STD-002/003)

    Ability of plating (parts/PCBs) to wet with solder.

    Finish, Flux

    SPI

    Solder Paste Inspection—3D volume/area/height before placement.

    AOI, Print window

    SPC

    Statistical Process Control—charts/limits to detect drift (Cp/Cpk, Ppk).

    Window, Run chart

    SQE

    Supplier Quality Engineer—owns SCARs, audits, incoming plans.

    Supplier, PPAP

    Stencil (step/nano)

    Metal foil that prints paste; step areas tune volume.

    Aperture, Aspect ratio

    Supermarket (line-side)

    Small, controlled inventory near the cell to avoid starvation.release

    Kanban, Kitting

    SWI

    Standard Work Instruction (photos + callouts) at the station.

    OPL, Golden pack

    Takt

    Beat of production (available time / demand).

    Line balance, Bottleneck

    TAL

    Time Above Liquidus—portion of reflow profile when solder is liquid.

    Profile, Voids

    Tape & reel / Tray / Stick

    Component packaging styles for SMT.

    Leader, Feeder

    TAR (Test Accuracy Ratio)

    Reference accuracy vs DUT tolerance (target ≥4:1).

    Calibration, MSA

    TC / ΔT

    Thermocouple / temperature rise over ambient.

    Profile, Burn-in

    TE / PE / QE / ME

    Test / Process / Quality / Manufacturing Engineer roles.

    Roles & handoffs

    Thermal pad (TIM)

    Interface material (pad/grease/PCM) between hot part and sink.

    Compression %, Cross-torque

    Threadlocker

    Anaerobic resin to lock screws (blue/purple/red grades).

    Torque, Prevailing-torque

    TIM

    Thermal Interface Material—pads, paste, phase-change.

    Heat sink, Compression

    Tombstone

    2-pin chip stands up during reflow (one end lifts).

    Aperture, Placement

    Torque map

    Posted table of torque setpoints (and condition: dry/oiled/243).

    Residual torque, Verification

    Traceability (IPC-1782

    )

    Lot → unit genealogy depth; labels/DB links in MES.

    Serialization, 2D code

    Traveler

    Packet/record that moves with the unit through operations.

    MES, Route

    UUT / DUT

    Unit/Device Under Test—what the fixture is exercising.

    FCT, ICT

    Vac decay / Pressure decay

    Leak test methods for IP enclosures.

    IP rating, Seal

    Via-in-pad

    Plated via placed in a pad; good routing, tricky assembly.

    Fill/Cap, Planarity

    V-score / Tab-route

    Panel breakaway methods (scored lines / tabs with mouse bites).

    Panelization, Depanel

    Void (BGA/thermal)

    Gas pockets in solder; limited by % area rules.

    AXI, Profile, N₂

    Wave / Selective solder

    Bulk THT solder processes (whole board / targeted nozzles).

    Fluxing, Preheat, Bridging

    WHMA-A-620

    Acceptability standard for cable/wire harnesses.

    Crimp height, Pull force

    Window (process)

    Range of settings where the process is stable (print/place/reflow).

    DOE, SPC

    Witness mark

    Paint line across screw head and base to show if it moved.

    Torque, Audit

    WIP

    Work In Process—units not yet complete; track by operation/state.

    MES, Supermarket

    X-out

    Defective board in a panel marked to prevent use.

    Panelization, Routing

    XRF

    X-ray fluorescence; measures plating thickness/materials.

    Solderability, RoHS

    ZIF

    Zero-Insertion-Force FFC/FPC or socket with a latch.

    FFC/FPC, Tug test



    B.3 Shop-floor slang (fast decode)

    • Andon — Visual alert (light/tile) that help is needed; can stop the line.
    • Brick — Device rendered unbootable (usually firmware error).
    • Dogbone via — Teardrop pad-to-via shape in layout to strengthen the neck.
    • Grape/Graping — Solder paste dries into beads (insufficient heat/paste).
    • Hot lot — Expedite this lot now.
    • Red tag — Quarantine marker (failed unit/lot).
    • Rope band — Twisted stretch-wrap pass under pallet deck to tie load.
    • Shadow board — Pegboard outlines for tools (easy to see what’s missing).
    • Ship stopper — Defect that blocks any shipment until fixed.
    • Snowman — Two coalesced solder balls/beads (paste/print issue).
    • Squeeze-out — Small, even bead of TIM visible after torque (a good sign).
    • Tug test — Gentle pull on a mated connector housing to confirm full engagement.



    Keeping terminology consistent ensures smoother communication, faster problem-solving, and fewer disputes. The result is a more connected operation where decisions trace back to standards instead of guesswork.


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