Blunkelectronicowner:Dipl.Ing.MarioBlunkBuchfinkenweg399097Erfurt/Germany

cellular+49(0)17629045855officephone+49(0)36160225184emailmario.blunk@blunkelectronic.dewebwww.blunkelectronic.de

VATIDDE292765719GermanTaxID151/208/15161

DesignChecklistforElectronicSchematicsandPCBLayouts

Doc.Version201406041

Abstract:Guidelineandchecklistfordevelopmentanddrawingofelectroniccircuits,schematicsandPCBlayouts.Focusisonissuescriticalforsystemreliability,stability,testabilityandmanufacturingoftenneglectedandrarelycoveredbytextbooks.SpecialsregardingtheusageoftheCAEtoolEAGLE1Version6.5.xarealsotouched.

Keywords:devicemodels,PCB,library,ratings,BoundaryScan,JTAG,IEEE1149.1,jumper,designators,values,numbers,netclass,placement,alternativefitting,DFT,SMD,THT,reset,powerup,powercycling,FPGA,CPLD,pullresistors,unusedpins,floatingpins,ESD,vectorfont,prototype,solderstoplacquer,shorts,trackwidth,temperature,thickness,drillsize,connectors,via,pad,referencemarks,German,English,translation,DRC,ERC,polygons,airwire,IC,pullresistors,dynamic,static,rise/falltime,silkscreen,width,GerberData,drill,tolerances,slittedhole,slottedhole,millings,plated

1 EAGLEisaregisteredtrademarkofCadSoftComputerGmbH.

Blunkelectronicatwww.blunkelectronic.de 1

http://www.blunk-electronic.de/http://www.blunk-electronic.de/mailto:mario.blunk@blunk-electronic.de

1 IntroductionByprovidingthischecklistIletmycustomersparticipateinmyexpertiseIhavebeencollectingoveryearsasdesignandtestdevelopmentengineer.Somepointsofthisworkprobablydonotappearinmosttextbooks.

IdonotintendtoaddressacademicproblemsofelectronicsbutfairlysimplerulesthatgetneglectedorforgottenduringschematicsandPCBdesign.Takingthoserulesseriousmuchwastingoftimeandmoneycanbeavoided.

Thelinespacingthroughoutthisdocumentisleftintentionallylargetogivethereaderspaceforpersonalnotes.

ActionstodowithaCADorCAEtoolarereferredtoCadSoftEAGLE.Ingeneraltheyapplytoothertools(likeAltiumDesigner,OrCad,)toowherecertainnamesandoperationsarenameddifferently.

SpecialthankstoA.ZaffranatCadSoftComputerGmbHathttp://www.cadsoftusa.comforthetablesintheappendix.TheyhavebeenwritteninGerman.AtranslationtablefromGermanto Englishkeywordscanalsobefoundthere.

Iappreciateallofcriticstoimprovethequalityofthisdocument!

Thisdocumentwaswrittenincooperationwith

AlereTechnologiesGmbH(Jena/Germany)

www.alere.com

2 Blunkelectronicatwww.blunkelectronic.de

http://www.alere.com/http://www.cadsoftusa.com/http://www.blunk-electronic.de/http://www.alere.com/

Contents1Introduction.........................................................................................................................22Library................................................................................................................................5

2.1Symbols.......................................................................................................................52.2Packages....................................................................................................................5

2.2.1TextsandFonts....................................................................................................52.2.2Outline&Keepout...............................................................................................62.2.3Drills&Holes.......................................................................................................6

2.3Devices.......................................................................................................................82.3.1Pinout...................................................................................................................8

3Schematic...........................................................................................................................93.1DevicePrefixes............................................................................................................93.2DeviceNumbering......................................................................................................93.3DeviceValues...........................................................................................................103.4Attributes...................................................................................................................123.5Connector/JumperPinoutPolicies............................................................................133.6AlternativeFitting.......................................................................................................143.7MinimizeDiversity.....................................................................................................153.8SparePartsandAccessories....................................................................................163.9TextsandFonts.........................................................................................................163.10VersionNumbers.....................................................................................................173.11ERC..........................................................................................................................17

4CircuitBehavior................................................................................................................185CircuitReliability...............................................................................................................30

5.1Transistors.................................................................................................................305.2Capacitors.................................................................................................................305.3Resistors...................................................................................................................30

6PCBLayout......................................................................................................................316.1PriortoRouting..........................................................................................................31

6.1.1BoardOutline/Dimensions..................................................................................316.1.2MountingHoles..................................................................................................316.1.3PlacementinGeneral.........................................................................................326.1.4PlacementofConnectors,Jumpers,Switches,LEDs,Displays........................346.1.5TextsandFonts..................................................................................................356.1.6Referencemarks/Fiducials...............................................................................356.1.7SolderPadsforModificationsorExtensions.....................................................36

6.2WhileRouting............................................................................................................386.2.1Solderstoplacquer/mask................................................................................396.2.2Polygons............................................................................................................406.2.3SlittedHolesinInnerLayers..............................................................................426.2.4SilkScreenIssues.............................................................................................45

6.2.4.1OverlapswithPads.....................................................................................456.2.4.2OverlapswithTextsinTop/BottomLayer...................................................466.2.4.3AttributeFUNCTION..................................................................................466.2.4.4TextLineWidth(Ratio)...............................................................................47

7GeneratingCAMFiles......................................................................................................53

Blunkelectronicatwww.blunkelectronic.de 3

http://www.blunk-electronic.de/

7.1PCBspecification.......................................................................................................537.2PlacementCoordinates.............................................................................................537.3DesignRules.............................................................................................................537.4CAMProcessor.........................................................................................................547.5BillofMaterial(BOM)................................................................................................54

8Appendix..........................................................................................................................559UsefulLinks......................................................................................................................6210References.....................................................................................................................6511Disclaimer.......................................................................................................................65

4 Blunkelectronicatwww.blunkelectronic.de

http://www.blunk-electronic.de/

2 LibrarySincethedevicelibraryprovidesthesmallestentitiesofaschematicandPCBlayout,itdeservesmostdetailedchecksandverificationspriortotheactualdesignofinterest.Somegeneralrules:

1. ManufacturersofCAD/CAEsystemsusuallydonotguaranty100%correctness!

2. Pleasebecautious(evenparanoid)whenimportingthirdpartydevicemodels.

2.1 SymbolsSymboleditingrequiressoundknowledgeofschematicdesign.

Makesure:

1. thesymbolofadeviceisunambiguousandrepresentstheaffectedpartasdetailedasnecessary.

2. fixedfontisusedinthes