Hardware Prototype Planning


The connector-placement pass previously established these intended orientations:
  • J1/JD: 270°, outward left
  • J3–J6: 90°, outward right
  • J8/J9: 180°, outward top
  • J2/J7: 0°, outward bottom
  • Both Ethernet jacks oriented consistently toward their assigned outside edge
  • All components remain top-side assembly only
Since then, the authoritative stackup was finalized as custom-4-layer:
  • Top: 0.070 mm / 2 oz
  • Mid-Layer 1: 0.035 mm / 1 oz, ground plane
  • Mid-Layer 2: 0.035 mm / 1 oz, power plane
  • Bottom: 0.070 mm / 2 oz
I cannot perform the requested live reconciliation or continue mutations because no ACUs are currently available.
Remaining work:
  • Verify connector layers, rotations, mating faces, edge clearances, and 3D seating in the live PCB.
  • Confirm JD’s correct physical part/land pattern; preserve its existing electrical pin mapping.
  • Apply custom-4-layer to the board.
  • Complete the component Layout/footprint metadata audit.
  • Verify 170 top-side and 0 bottom-side components.
  • Run placement DRC and correct overlaps/courtyard violations.
  • Apply the supplied JLCPCB rules, then proceed to routing and manufacturing export.
On the 4 position molex power connector, which pins are ground an which ones are 12vdc?
For the 4-position Molex power-input connector J1:
  • Pins 1 and 2: +12V_IN
  • Pins 3 and 4: GND
The two pins on each rail are paralleled for current handling. TP1 is currently tied to J1 pin 3, so its net is GND.

Schematic and PCB Handoff Package Template
Purpose: This package provides the requirements and source evidence needed to create, verify, lay out, and release a fabrication-ready PCB. Replace every bracketed instruction. Use TBD for unresolved items—never leave an important field silently blank.
Document Control

Table


FieldEntry
Project name[Project name]
Product / assembly number[Number]
Hardware revision[Rev]
Document revision[Rev]
Prepared by[Name / organization]
Date[YYYY-MM-DD]
Approval authority[Name / role]
Intended fab / assembler[Company or TBD]
Confidentiality[Public / confidential / export-controlled, etc.]
Revision History

Table


Document RevDateAuthorChangesApproved By
A[Date][Name]Initial release[Name]
Requirement Language
  • MUST: mandatory and acceptance-critical.
  • SHOULD: preferred; deviations require documentation.
  • MAY: optional.
  • Every assumption must be marked ASSUMPTION and resolved before manufacturing release.

1. Package Manifest
List every supplied file and identify which file is authoritative if sources conflict.

Table


File / FolderFormatRevisionPurposeAuthority / Priority
This specificationMarkdown[Rev]Requirements and design intentPrimary for requirements
BOMCSV/XLSX[Rev]Approved componentsPrimary for MPNs
ConnectivityCSV[Rev]Pin-level electrical connectionsPrimary for netlist
Board outlineDXF[Rev]PCB perimeter, slots, holesPrimary for 2D geometry
EnclosureSTEP[Rev]Mechanical fitPrimary for 3D fit
DatasheetsPDF[Rev/date]Component constraintsPrimary for component limits
Conflict rule: [Example: latest manufacturer datasheet governs electrical and land-pattern constraints; released mechanical drawing governs connector position; this specification governs product requirements.]

2. Product Overview and Theory of Operation
2.1 Purpose
[One concise paragraph describing what the product does, who or what uses it, and its primary operating environment.]
2.2 Theory of Operation
Describe operation from power application through normal use and shutdown. Include:
  1. Power entry and protection.
  2. Rail generation and sequencing.
  3. Controller startup and programming.
  4. Sensor, actuator, communications, and user-interface behavior.
  5. Fault detection and safe-state behavior.
  6. Shutdown and energy-discharge behavior.
2.3 Functional Block Diagram
[Insert or link a diagram. Label every power rail and inter-block interface.]
2.4 Operating Modes

Table


ModeEntry ConditionActive BlocksTypical CurrentPeak CurrentExit ConditionSafe State
Off[Condition][Blocks][A][A][Condition][State]
Startup[Condition][Blocks][A][A][Condition][State]
Normal[Condition][Blocks][A][A][Condition][State]
Fault[Condition][Blocks][A][A][Condition][State]
2.5 Breadboard / Prototype Evidence

Table


TestConfigurationInput ConditionsMeasured ResultPass CriterionEvidence File
[Test][Setup][Conditions][Result][Criterion][File/photo/log]
List known differences between the breadboard and intended PCB:

Table


DifferencePCB RiskRequired Mitigation / Verification
[Long jumper wires vs PCB traces][Risk][Action]

3. Scope, Constraints, and Acceptance
3.1 Included Scope
  • [Schematic capture]
  • [PCB stackup and board outline]
  • [Placement and routing]
  • [ERC/DRC review]
  • [Gerber, drill, BOM, and pick-and-place outputs]
  • [Other]
3.2 Excluded Scope
  • [Firmware]
  • [Enclosure changes]
  • [Certification testing]
  • [Other]
3.3 Product-Level Requirements

Table


IDRequirementPriorityVerification MethodPass Criterion
SYS-001[Requirement]MUST[Inspection/test/analysis][Measurable criterion]
3.4 Open Decisions

Table


IDQuestion / DecisionOptionsDecision OwnerDue BeforeStatus
TBD-001[Question][Options][Owner][Schematic/layout/release]Open

4. Environmental, Reliability, and Regulatory Requirements

Table


ParameterMinimumNominalMaximumUnitsNotes / Standard
Operating temperature[ ][ ][ ]°C[Ambient or board]
Storage temperature[ ][ ][ ]°C
Relative humidity[ ][ ][ ]%RH[Condensing/non-condensing]
Altitude[ ][ ][ ]m
Shock / vibration[ ][ ][ ][Units][Standard/profile]
Pollution degree[ ][ ]
Expected service life[ ][ ]years/hours
Applicable Standards

Table


Standard / RequirementEditionApplicable SectionDesign ImpactEvidence Required
IPC-2221[Edition][Section]General PCB designDRC / review
IPC-7351[Edition][Section]Land patternsFootprint review
[UL/IEC/FCC/CE/etc.][Edition][Section][Impact][Evidence]
Materials and Compliance

Table


RequirementRequired?Evidence / Notes
RoHS[Yes/No][Declaration]
REACH[Yes/No][Declaration]
Halogen-free[Yes/No][Requirement]
Lead-free assembly[Yes/No][Process]
Conformal coating[Yes/No][Keepout/coverage]

5. Electrical Interfaces and Performance
5.1 External Interfaces

Table


Interface IDConnectorDirectionProtocol / SignalVoltageFrequency / Data RateCable / Mating PartHot-Plug?Protection Required
IF-001J1Input[Power/USB/etc.][V][Rate][MPN][Yes/No][ESD/surge/etc.]
5.2 Connector Pinout

Table


ConnectorPinSignal / NetDirectionVoltage / Logic StandardMax CurrentMate-First / LastNotes
J11[Net][In/Out/Bidir][Standard][A][If applicable][Notes]
5.3 Signal Requirements

Table


Net / BusSourceDestination(s)StandardFrequency / Edge RateImpedanceLength / Skew LimitLayer / Via LimitTermination
[USB_DP/DM][Source][Destination][USB 2.0][Rate][90 Ω diff][Limits][Limits][Type]
5.4 Analog Requirements

Table


SignalRangeBandwidthSource ImpedanceRequired Accuracy / NoiseADC/DAC ReferenceRouting / Guarding Notes
[Signal][Range][Hz][Ω][Requirement][Reference][Notes]
5.5 Clocks and Timing

Table


ClockSourceConsumersFrequencyAccuracy / JitterRouting ConstraintDatasheet Source
[Clock][Source][Loads][Hz][ppm/ps][Constraint][PDF/page]

6. Power Architecture and Power Budget
6.1 Power Sources

Table


SourceConnector / ComponentMin VoltageNominalMax VoltageContinuous CurrentPeak Current / DurationReverse Polarity?Transient / Surge
[Source][J/U][V][V][V][A][A/ms][Yes/No][Requirement]
6.2 Power Rails

Table


RailSource / RegulatorVoltage Min/Nom/MaxLoad TypicalLoad PeakRipple LimitStartup OrderPower-Good UseShutdown / Discharge
+3V3[U#][V/V/V][A][A][mVpp][Order][Use][Method]
6.3 Load Budget

Table


Load RefDes / BlockRailModeTypical CurrentMaximum CurrentDuty CycleSource / Evidence
[U1]+3V3Normal[A][A][%][Datasheet/test]
6.4 Protection and Grounding

Table


Location / NetHazardProtectionRatingPlacement RequirementReturn Path / Ground Domain
Power input[Reverse/surge][Fuse/TVS/MOSFET][Rating][Constraint][Return]
Describe ground strategy, chassis connection, shield termination, analog/digital partitioning, and any intentional net ties: [Description].

7. Approved Bill of Materials
Supply a separate BOM.csv using these exact columns:

CSV Data


RefDesQtyManufacturerMPNDescriptionValuePackageMountingDatasheet_FileDatasheet_URLLifecycle_StatusTemperature_GradeVoltage_RatingCurrent_RatingToleranceApproved_Alternate_MPNSubstitution_PolicySupplier_SKUAssembly_NotesCritical_PartNotes
BOM Rules
  • RefDes may contain a comma-separated set only for truly identical fitted components.
  • MPN must be the manufacturer part number; distributor SKUs are supplemental.
  • Mark each part No substitutions, Approved alternates only, or Equivalent allowed.
  • Include DNI/DNP items and clearly identify their assembly state.
  • Identify safety, RF, precision, thermal, connector, crystal, and power-path parts as critical.
BOM Review Table

Table


RefDesMPN VerifiedSymbol VerifiedPinout VerifiedFootprint Verified3D / Height VerifiedLifecycle VerifiedReviewer
[U1][ ][ ][ ][ ][ ][ ][Name]

8. Pin-Level Connectivity and Net Definition
Supply a separate CONNECTIVITY.csv using these exact columns:

CSV Data


Net_NameEndpoint_1Endpoint_2Additional_EndpointsNet_ClassVoltage_MinVoltage_NominalVoltage_MaxTypical_CurrentMaximum_CurrentDirectionSource_BlockDestination_BlockCriticalityPull_or_TerminationTest_PointRouting_NotesVerification_Source
Endpoint syntax must be RefDes.PinNumber, for example U1.14. Use manufacturer pin numbers, not only pin names.
Connectivity Rules
  • Every physical connector pin must appear.
  • Every IC power and ground pin must appear.
  • Each decoupling capacitor must identify the specific pin/rail it supports.
  • Define unused pins as NC, reserved, tied high/low, or test-only according to the datasheet.
  • Explicitly identify net ties, chassis ground, shields, Kelvin sense connections, and analog references.
  • Include programming, debug, test, manufacturing, and fixture nets.
  • Preserve polarity suffixes consistently: _P/_N or +/-.
Net Class Table

Table


Net ClassIncluded NetsWidth RuleClearance RuleVia RuleLayer RuleImpedance / PairingNotes
POWER_HIGH[Nets][mm][mm][Via size/count][Layers]N/A[Notes]
SIGNAL_STD[Nets][mm][mm][Rule][Layers][If any]
DIFF_[NAME][Pair][Derived][Derived][Rule][Layers][Ω]
Unused Pin Table

Table


RefDesPinPin NameRequired TreatmentDatasheet Page / SectionImplemented Net
[U1][#][Name][NC/tie/pull][Citation][Net]

9. Component Datasheet Constraint Register
Attach the exact PDF revision for every critical component. Use this table to make layout-critical requirements explicit.

Table


RefDesMPNDatasheet File / RevConstraint TypeExact RequirementPage / Figure / SectionMandatory?Implementation / Verification
U1[MPN][PDF]Decoupling[Requirement][Page]MUST[Method]
U1[MPN][PDF]Thermal vias[Pattern][Page]MUST[Method]
J1[MPN][PDF]Edge placement[Dimension][Page]MUST[Method]
Capture at least:
  • Recommended land pattern and solder-mask/paste guidance.
  • Exposed-pad connection and thermal-via pattern.
  • Decoupling values, pin association, and maximum placement distance.
  • Switching-current loop, switch-node, bootstrap, feedback, and compensation placement.
  • Crystal/resonator placement and guard/return guidance.
  • Antenna, RF, magnetics, and isolation keepouts.
  • Thermal, airflow, heatsink, and copper-area requirements.
  • Connector board-edge datum, mating envelope, and insertion/removal access.
  • Creepage, clearance, isolation slot, and high-voltage restrictions.

10. Mechanical Definition
10.1 Coordinate System

Table


ItemDefinition
UnitsMillimeters
Origin[Example: lower-left board-outline corner]
X direction[Definition]
Y direction[Definition]
Z direction[Definition]
Viewed side[Top / bottom]
Rotation convention[Clockwise/counterclockwise]
Datum hierarchy[Primary/secondary/tertiary]
10.2 Board Geometry

Table


RequirementValue / FileToleranceMandatory?Notes
Board outlineboard-outline.dxf[mm]MUST[Notes]
Finished thickness[mm][mm]MUST
Maximum dimensions[X × Y mm][mm]MUST
Corner radius / chamfer[Value][mm][ ]
Edge plating / castellations[Requirement][mm][ ]
10.3 Holes, Slots, and Cutouts

Table


IDTypeXYFinished SizePlated?ToleranceCopper KeepoutComponent KeepoutPurpose
H1[Hole/slot][mm][mm][mm][Yes/No][mm][mm][mm][Purpose]
10.4 Enclosure and Mating Geometry

Table


ItemMating Part / FileLocation DatumRequired ClearanceInsertion / Service EnvelopeNotes
[Connector][MPN/STEP][Datum][mm][Envelope][Notes]

11. Placement Requirements
Supply PLACEMENT_CONSTRAINTS.csv using these exact columns:

CSV Data


Constraint_IDRefDes_or_GroupConstraint_TypeTarget_or_DatumX_mmY_mmRotation_degSideTolerance_mmMaximum_Distance_mmMinimum_Distance_mmMaximum_Height_mmPriorityReasonSourceVerification_Method
Allowed Constraint_Type examples: Fixed, Board edge, Near, Away from, Aligned, Grouped, Ordered, Same side, Height limit, Thermal, Symmetry, Test access.
Placement Table

Table


IDRefDes / GroupConstraintTarget / DatumLimit / TolerancePriorityEngineering ReasonSource
PLC-001J1Fixed position and rotationBoard datum[±mm/deg]MUSTEnclosure matingDrawing
PLC-002C1, C2Near associated U1 pinsU1.[pins][max mm]MUSTHigh-frequency bypassDatasheet
Placement Order
  1. Board-edge and mechanically fixed components.
  2. Mounting holes, cutouts, and mating components.
  3. Antennas, isolation barriers, and mandatory keepouts.
  4. Power converters and critical current loops.
  5. Clocks, high-speed interfaces, and sensitive analog circuits.
  6. Controllers and functional groups.
  7. Decoupling, pull components, test points, and remaining passives.
Component Height Zones

Table


ZonePolygon / Drawing ReferenceSideMaximum HeightMeasurement DatumNotes
HZ-1[Reference]Top[mm]PCB top surface[Notes]

12. Keepout and Restricted-Area Register
Supply KEEPOUTS.csv using these exact columns:

CSV Data


Keepout_IDNameSource_RefDesGeometry_File_or_DefinitionDatumSide_or_LayersProhibits_ComponentsProhibits_CopperProhibits_TracesProhibits_ViasProhibits_PoursHeight_Limit_mmClearance_mmPriorityReasonSource_CitationVerification_Method

Table


IDRegionGeometry / DatumLayersComponentsCopper / PoursTracesViasClearance / HeightSource
KO-001Antenna[Drawing]AllNoNoNoNo[mm]Datasheet page [ ]
KO-002Mounting holeH1 centerAllNoNoNoNo[mm radial]Mechanical drawing
KO-003Switch nodeU1/L1 region[Layers][Rule][Rule]RestrictedNo[mm]Regulator datasheet
For each region, distinguish among:
  • Component-body keepout.
  • Courtyard / assembly-tool access.
  • Copper-pour keepout.
  • Trace keepout.
  • Via keepout.
  • Solder-mask or paste restriction.
  • Height restriction.
  • RF/antenna keepout.
  • High-voltage isolation barrier.
  • Enclosure or fastener sweep envelope.

13. PCB Stackup and Fabrication Capabilities
13.1 Four-Layer Stackup
Do not finalize controlled-impedance widths until the intended fabricator confirms dielectric thickness and material properties.

Table


LayerFabricator Layer NameTypeCopper Weight / ThicknessDielectric to Next LayerMaterial / DkPrimary Use
L1TopSignal[oz/µm][mm][Material/Dk]Components / signals
L2Inner 1Plane[oz/µm][mm][Material/Dk]Continuous ground
L3Inner 2Plane/signal[oz/µm][mm][Material/Dk]Power / slow signals
L4BottomSignal[oz/µm]Signals / components
13.2 Fabricator Capability Table

Table


ParameterPreferredAllowed Maximum / MinimumFabricator Confirmed?Source
Minimum trace width[mm][mm][Yes/No][Capability page]
Minimum spacing[mm][mm][Yes/No]
Minimum drill[mm][mm][Yes/No]
Minimum annular ring[mm][mm][Yes/No]
Copper-to-edge[mm][mm][Yes/No]
Solder-mask dam[mm][mm][Yes/No]
Board thickness tolerance[mm][mm][Yes/No]
13.3 Surface Finish and Construction

Table


ItemRequirement
Base material[FR-4 grade/Tg]
Surface finish[ENIG/HASL/etc.]
Solder mask[Color/type]
Silkscreen[Color/sides]
Copper weight[Outer/inner]
Via fill / cap[Requirement]
Controlled impedance coupon[Yes/No]
Panelization[Fab/assembler/user]

14. Routing, Width, Clearance, and Via Rules
14.1 Trace and Clearance Rules

Table


Rule IDNet / Net ClassWidthClearanceLayer(s)Maximum LengthMaximum ViasReturn-Path RequirementCalculation / Source
RT-001[Class][mm][mm][Layers][mm][#][Requirement][IPC/current/impedance]
14.2 Differential Pair Rules

Table


PairP NetN NetDifferential ImpedanceSingle-Ended ImpedanceWidthGapIntra-Pair SkewMax LengthVia SymmetryReference Plane
[Pair][Net][Net][Ω][Ω][Fab-derived][Fab-derived][mm/ps][mm][Rule][Plane]
14.3 Power Trace / Plane Sizing

Table


RailMaximum CurrentAllowed Temperature RiseCopper ThicknessExternal/InternalMinimum Width / AreaVia CountCalculation Method
[Rail][A][°C][µm][Location][mm/mm²][#][IPC-2152/analysis]
14.4 Via Definitions

Table


Via TypeDrillFinished HolePad DiameterAnnular RingLayersFill / CapAllowed UsesProhibited Uses
Signal through-via[mm][mm][mm][mm]L1-L4[None][Use][Restriction]
Thermal via[mm][mm][mm][mm][Layers][Tent/fill][Use][Restriction]
14.5 Critical Routing Topologies

Table


Circuit / NetRequired TopologyPlacement DependencyForbidden GeometryReturn PathVerification
Regulator feedbackKelvin sense from output[Constraint]Near switch nodeQuiet groundLayout review
CrystalShort, symmetric[Constraint]Vias/stubsLocal groundLayout review

15. Footprint and Land-Pattern Requirements

Table


RefDesPackageAuthoritative DrawingLand Pattern SourceDensity LevelThermal PadPaste ReductionCourtyardPin-1 VerificationDeviations
[U1][Package][PDF/page][Manufacturer/IPC][A/B/C][Details][%/window][mm][Method][None/list]
Footprint acceptance requires verification of:
  • Pin count, numbering, orientation, and pin-1 marking.
  • Pad dimensions and pitch.
  • Exposed-pad dimensions and connectivity.
  • Solder-mask expansion and paste apertures.
  • Courtyard and component-body dimensions.
  • Board-edge relation, locating pegs, shield tabs, and mounting posts.
  • 3D body size, seating plane, height, and mating envelope.

16. Thermal Design

Table


Component / RegionDissipation TypicalDissipation Worst CaseJunction LimitAmbientAllowed RiseThermal PathCopper / Via RequirementVerification Method
[U1][W][W][°C][°C][°C][Path][Requirement][Analysis/test]
Include airflow direction, enclosure thermal constraints, heat-source separation, heatsinks, thermal interface materials, and temperature-sensor placement: [Details].

17. Test, Programming, and Manufacturing Access
17.1 Test Points

Table


Test PointNetPurposeSideMinimum Pad / Probe TypeRequired ClearanceFixture Coordinates Required?
TP1[Net][Purpose][Top/bottom][Size/type][mm][Yes/No]
17.2 Programming / Debug

Table


InterfaceConnector / PadsPinoutVoltageAccess MethodBoot-Strap RequirementsProduction Use
[SWD/JTAG/etc.][RefDes][Reference][V][Cable/pogo][Details][Method]
17.3 Assembly Constraints

Table


ConstraintRequirementSource / Reason
Component side[Top only / both][Reason]
Hand soldering[Components][Access]
Rework access[Requirement][Reason]
Fiducials[Global/local requirements][Assembler]
Tooling holes[Requirement][Assembler]
Panel rails[Requirement][Assembler]

18. Silkscreen, Marking, and Traceability

Table


MarkingRequired Text / FormatLayerMinimum SizeLocation Constraint
Board name[Text]Top silk[mm][Location]
Hardware revision[Format][Layer][mm][Location]
Serial / lot code[Format][Layer][mm][Location]
Connector labels[Labels][Layer][mm]Adjacent and visible
Pin 1 / polarity[Requirement][Layer][mm]Unambiguous
State logo, certification, date-code, barcode/QR, and company-mark requirements: [Details].

19. Schematic Capture Requirements
The schematic must:
  • Be organized by functional block and left-to-right signal/power flow.
  • Use consistent, meaningful net names matching this package.
  • Show connector pin numbers and external signal direction.
  • Show all power pins, grounds, hidden pins, and unused-pin treatment.
  • Place bypass parts near the IC section they support and label their role.
  • Annotate critical values, tolerances, ratings, MPNs, and package information.
  • Show net ties, shields, chassis ground, analog ground, and isolation boundaries explicitly.
  • Include programming, test, and manufacturing interfaces.
  • Include design notes for layout-critical circuits.
  • Pass electrical-rule review with every exception documented.
Schematic Review Checklist

Table


CheckPass / FailReviewerEvidence / Notes
Every BOM part represented[ ][Name]
Connectivity matches source table[ ][Name]
Pin numbers verified against PDFs[ ][Name]
Power and ground pins complete[ ][Name]
Unused pins treated correctly[ ][Name]
Decoupling and support circuits complete[ ][Name]
Net names and polarities consistent[ ][Name]
ERC errors resolved or waived[ ][Name]

20. PCB Verification and Release Criteria
20.1 Layout Review Checklist

Table


CheckPass / FailEvidence / ReportReviewer
Board outline and holes match authoritative geometry[ ][File][Name]
All fixed components match datums[ ][Report][Name]
Component bodies/courtyards do not overlap[ ][DRC][Name]
Height zones and enclosure fit pass[ ][3D review][Name]
All keepouts are implemented[ ][Rule review][Name]
Critical loops and return paths reviewed[ ][Review][Name]
Controlled-impedance geometry matches fab stackup[ ][Fab data][Name]
Differential-pair skew and continuity pass[ ][Report][Name]
Power paths meet current/thermal requirements[ ][Calculation][Name]
Antenna/RF/isolation requirements pass[ ][Review][Name]
Test/programming access verified[ ][Review][Name]
No unintended unrouted connections[ ][Report][Name]
DRC passes; waivers documented[ ][DRC][Name]
20.2 DRC / ERC Waiver Register

Table


Waiver IDViolationLocationReason AcceptedRiskApproved ByDate
WVR-001[Violation][Location][Reason][Risk][Name][Date]
20.3 Release Deliverables

Table


DeliverableRequired FormatNaming ConventionGenerated?Reviewed?
Fabrication layersGerber X2 or fab-required[Convention][ ][ ]
Drill filesExcellon[Convention][ ][ ]
Drill mapPDF/Gerber[Convention][ ][ ]
Board drawing / fab notesPDF[Convention][ ][ ]
Assembly drawingPDF[Convention][ ][ ]
BOMCSV/XLSX[Convention][ ][ ]
Pick-and-placeCSV[Convention][ ][ ]
SchematicPDF/native[Convention][ ][ ]
PCB sourceNative[Convention][ ][ ]
3D board modelSTEP[Convention][ ][ ]
Readme / release notesTXT/MD/PDF[Convention][ ][ ]
20.4 Manufacturing Release Approval

Table


RoleNameApprovalDateNotes
Electrical design[Name][ ][Date]
PCB layout[Name][ ][Date]
Mechanical[Name][ ][Date]
Manufacturing[Name][ ][Date]
Product owner[Name][ ][Date]

21. Assumptions, Risks, and Deviations
21.1 Assumptions

Table


IDAssumptionDesign ImpactOwnerResolution Required ByStatus
ASM-001[Assumption][Impact][Owner][Milestone]Open
21.2 Risk Register

Table


Risk IDRiskCauseProbabilitySeverityMitigationVerificationOwnerStatus
RSK-001[Risk][Cause][L/M/H][L/M/H][Action][Test/review][Owner]Open
21.3 Approved Deviations

Table


Deviation IDRequirementDeviationTechnical JustificationApprovalDate
DEV-001[Requirement][Deviation][Reason][Name][Date]

Text


/PCB-Handoff
  PCB_DESIGN_SPEC.md
  BOM.csv
  CONNECTIVITY.csv
  PLACEMENT_CONSTRAINTS.csv
  KEEPOUTS.csv
  /datasheets
    manufacturer-part-number_rev.pdf
  /mechanical
    board-outline.dxf
    enclosure.step
    connector-and-mating-drawings.pdf
  /stackup
    fabricator-stackup.pdf
    impedance-table.pdf
  /references
    theory-of-operation.pdf
    block-diagram.pdf
    breadboard-photos/
    prototype-test-results/
    firmware-pin-map.csv
  /release
    [generated manufacturing outputs]
23. Appendix B — Final Intake Checklist
Before schematic work begins, confirm:
  • Theory of operation is complete.
  • Exact MPN BOM is attached.
  • Datasheet PDFs are attached for all critical components.
  • Pin-level connectivity is supplied or explicitly delegated for derivation.
  • Connector pinouts and mating parts are identified.
  • Power source limits and full load budget are supplied.
  • Board outline, holes, slots, and fixed component coordinates are supplied.
  • Enclosure and mating geometry are supplied where applicable.
  • Placement, height, access, and keepout constraints are identified.
  • Four-layer stackup and intended fabricator capabilities are supplied.
  • Interface speeds, impedance targets, and routing restrictions are identified.
  • Environmental, regulatory, safety, creepage, and clearance requirements are identified.
  • Test, programming, and manufacturing access requirements are identified.
  • Acceptance criteria and approval authority are defined.
  • Every unresolved item is marked TBD with an owner and required decision milestone.
  • Schematic and PCB Handoff Package Template

  • Document Control

  • Revision History

  • Requirement Language

  • 1. Package Manifest

  • 2. Product Overview and Theory of Operation

  • 2.1 Purpose

  • 2.2 Theory of Operation

  • 2.3 Functional Block Diagram

  • 2.4 Operating Modes

  • 2.5 Breadboard / Prototype Evidence

  • 3. Scope, Constraints, and Acceptance

  • 3.1 Included Scope

  • 3.2 Excluded Scope

  • 3.3 Product-Level Requirements

  • 3.4 Open Decisions

  • 4. Environmental, Reliability, and Regulatory Requirements

  • Applicable Standards

  • Materials and Compliance

  • 5. Electrical Interfaces and Performance

  • 5.1 External Interfaces

  • 5.2 Connector Pinout

  • 5.3 Signal Requirements

  • 5.4 Analog Requirements

  • 5.5 Clocks and Timing

  • 6. Power Architecture and Power Budget

  • 6.1 Power Sources

  • 6.2 Power Rails

  • 6.3 Load Budget

  • 6.4 Protection and Grounding

  • 7. Approved Bill of Materials

  • BOM Rules

  • BOM Review Table

  • 8. Pin-Level Connectivity and Net Definition

  • Connectivity Rules

  • Net Class Table

  • Unused Pin Table

  • 9. Component Datasheet Constraint Register

  • 10. Mechanical Definition

  • 10.1 Coordinate System

  • 10.2 Board Geometry

  • 10.3 Holes, Slots, and Cutouts

  • 10.4 Enclosure and Mating Geometry

  • 11. Placement Requirements

  • Placement Table

  • Placement Order

  • Component Height Zones

  • 12. Keepout and Restricted-Area Register

  • 13. PCB Stackup and Fabrication Capabilities

  • 13.1 Four-Layer Stackup

  • 13.2 Fabricator Capability Table

  • 13.3 Surface Finish and Construction

  • 14. Routing, Width, Clearance, and Via Rules

  • 14.1 Trace and Clearance Rules

  • 14.2 Differential Pair Rules

  • 14.3 Power Trace / Plane Sizing

  • 14.4 Via Definitions

  • 14.5 Critical Routing Topologies

  • 15. Footprint and Land-Pattern Requirements

  • 16. Thermal Design

  • 17. Test, Programming, and Manufacturing Access

  • 17.1 Test Points

  • 17.2 Programming / Debug

  • 17.3 Assembly Constraints

  • 18. Silkscreen, Marking, and Traceability

  • 19. Schematic Capture Requirements

  • Schematic Review Checklist

  • 20. PCB Verification and Release Criteria

  • 20.1 Layout Review Checklist

  • 20.2 DRC / ERC Waiver Register

  • 20.3 Release Deliverables

  • 20.4 Manufacturing Release Approval

  • 21. Assumptions, Risks, and Deviations

  • 21.1 Assumptions

  • 21.2 Risk Register

  • 21.3 Approved Deviations

  • 22. Appendix A — Recommended Folder Structure

  • 23. Appendix B — Final Intake Checklist