pcb布线设计规则

DesignRulesReferenceSummaryTechnicalReferenceTR0116(v1.8)May20,2008ThiscomprehensivereferenceprovidesdetailedinformationonsettingupdesignrulesforaPCBdesign.Italsocoversadditionofrule-basedparameterstoobjectsintheschematicandDesignRuleChecking.Detailedinformationforeachoftheindividualruletypesandtheirassociatedconstraintsisalsoprovided.PCBdesignisnolongeramatterofplacingtrackstocreateconnections.HighspeedlogiccombinedwithsmallerandmorecomplexpackagingtechnologiesplacenewdemandsonthePCBDesigner.Itisnotpossibletosatisfyalltherequirementsofthedesignbyonlyconsideringtheclearancebetweentracks,padsandvias.Designstodaycanalsorequirethatyouapplyspecificrequirementstoindividualnets,componentsorregionsoftheboardaswellasconsideringsuchissuesascrosstalk,reflectionsandnetlengths.AltiumDesigner'sPCBEditorallowsyoutodefinedesignrulesthatmonitorandtestfortheseandotherrequirements.DesignrulescollectivelyformaninstructionsetforthePCBEditortofollow.Eachrulerepresentsarequirementofyourdesignandmanyoftherules,eg.clearanceandwidthconstraints,canbemonitoredasyouworkbytheonlineDesignRuleChecker(DRC).Certainrulesaremonitoredwhenusingadditionalfeaturesofthesoftware,forexamplerouting-basedruleswhenusingtheSitusAutoroutertorouteadesign,orsignalintegrity-basedrulesusedbytheSignalIntegrityAnalyzerwhenperformingadetailedsignalintegrityanalysisofadesign.ThePCBEditorprovidesapowerfulinterfacefromwhereyoucandefinethevariousdesignrulesasrequired.Therulesthemselvesaredividedintothefollowingcategories:•ElectricalElectricalRoutingSMTSignalIntegrityClearanceShort-CircuitUn-RoutedNetUn-ConnectedPinWidthRoutingTopologyRoutingPriorityRoutingLayersRoutingCornersRoutingViaStyleFanoutControlDifferentialPairsRoutingSMDtoCornerSMDtoPlaneSMDtoNeck-DownSolderMaskExpansionPasteMaskExpansionSignalStimulusOvershoot-FallingEdgeOvershoot-RisingEdgeUndershoot-FallingEdgeUndershoot-RisingEdgeImpedanceSignalTopValueSignalBaseValueFlightTime-RisingEdgeFlightTime-FallingEdgeSlope-RisingEdgeSlope-FallingEdgeSupplyNetsPlacementRoomDefinitionComponentClearanceComponentOrientationsPermittedLayersNetstoIgnoreHeightManufacturingMinimumAnnularRingAcuteAngleHoleSizeLayerPairsTestpointTestpointStyleTestpointUsagePowerPlaneConnectStylePowerPlaneClearancePolygonConnectStyleHighSpeedParallelSegmentLengthMatchedNetLengthsDaisyChainStubLengthViasUnderSMDMaximumViaCountMaskPlanePCBDesignRules•Placement•Routing•Manufacturing•SMT•Plane•Mask•Testpoint•HighSpeed•SignalIntegrity.Withawell-definedsetofdesignrules,youcansuccessfullycompleteboarddesignswithvaryingandoftenstringentdesignrequirements.ThisisfurtherenhancedbythefactthatthePCBEditorallowsyoutoexportandimportrulesets,enablingyoutostoreandretrieveyourfavoritedesignruleconfigurations,dependingonthejobathand.TR0116(v1.8)May20,20081DesignRulesReferenceCreatingandEditingDesignRulesinthePCBDocumentTosetupnewdesignrulesoreditexistingonesforthecurrentdesign,fromthePCBdocumentselectDesign»RulestoopenthePCBRulesandConstraintsEditordialog.Inthefolder-treepaneontheleftsideofthedialog,eachofthetendesignrulecategoriesarelistedundertheDesignRulesfolder.Clickontherootfolder(DesignRules)toaccessasummarylisting-inthemaineditingwindowofthedialog-ofallspecificrulesthathavebeendefinedforalldesignruletypes,acrossallcategories(asshowninthepreviousimage).Clickonacategorytolistallspecificrulesthathavebeendefinedforallassociateddesignruletypesofthatcategory.Clickonaruletypetolistallspecificrulesthathavebeendefinedforthattype.Ineachcase-whetheryouhaveclickedontherootfolder,acategoryoratype-themaineditingwindowofthedialogwilldisplaythefollowingsummaryinformationforeachdefinedrule:•therulename•thetypeofruleitis•therulecategoryitbelongsto•thescopeoftherule(i.e.whatobject(s)itappliesto)•theconstraintattributesthathavebeendefinedfortherule•therule'spriority.Youcanalsoenable/disablearulefromwithinthesesummarylistviews.2TR0116(v1.8)May20,2008DesignRulesReferenceCreatingaNewRuleAnewrulecanbecreatedbyright-clickingontherequiredruletypeinthefolder-treepaneandchoosingNewRulefromthepop-upmenu.Alternatively,pressingtheRuleWizardbuttonatthebottomofthedialogwilllaunchtheNewRuleWizard.FollowthepagesinthiswizardtoquicklycreateanewdesignruleofanytypeThenewrulewillbeaddedtothefolder-treeandwillalsoappearinthesummarylistforthatruletype.Therulenamewillappearboldtodistinguishitasbeingnewandyettobe'applied'.EditingaRuleToeditthescopeandconstraintattributesforarule,eitherclickontheentryfortheruleinthefolder-treepaneordouble-clickonitsentryinasummarylist.Themaineditingwindowofthedialogwillchangetogiveaccesstothecontrolsfordefiningthescopeandconstraintattributesforthatrule.TheexampleimagebelowshowsthecontrolsaccessedforaSolderMaskExpansionrule.Changesmadetoexistingruledefinitionsarehighlightedinboththefolder-treepaneandtheapplicablesummarylists.Suchentriesaredistinguishedbytherulenamebecomingboldandanasteriskdisplayedtotherightofthename.Theasteriskisusedtoreflectthattheruleisanexistingrulethathasbeenmodified,ratherthananewlycreatedrule(whichisdisplayedboldwithoutanasterisk).TR011