PrintedElectronicsandAdditiveMicroelectronicPackagingForRF/MicrowaveApplications

Prof.CraigArmientoUniversityofMassachusettsLowell

RaytheonUMassLowellResearchInstitute(RURI)PrintedElectronicsResearchCollaborative(PERC)

iMAPS NortheastWorkshop,May,2,20171

Outline

• ChallengesforPrintedElectronicsforRF/MicrowaveApplications

• PrintedElectronicsResearchthroughCorporate-AcademicPartnerships• Raytheon-UMassLowellResearchInstitute(RURI)• PrintedElectronicsResearchCollaborative(PERC)

• UniversityofMassachusettsLowell- FacilityandCapabilities

• SampleProjects• PrintedFrequencySelectiveSurfaces(FSS)• Ferroelectricinkandprintedvaractors/phaseshifters• Additivemicroelectronicpackaging• 3Dantennaarrays• Printedconnectors

• ClosingThoughts

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PrintedElectronicsandMicroelectronicPackaging• PrintedElectronicstechnologyworksinthedimensionalregimebetweenthesubmicron

geometriesofICsandthemuchlargerdimensionsofPCBs… whichisthescaleneededformicroelectronicpackaging

FeaturesizesICs<1micron packaging:10’sofmicrons PCBs:100’sofmicrons

• TheperformancerequirementsofRF/microwavesystemsrequirebestofbreedsemiconductoractiveICs

• PrintedRFtransistorsarenotreadyforprimetimeduetothelowmobilityofprintedsemiconductors• Microwavemodulesrequireavarietyofdifferentfunctionalitiesandrequiretheintegration

ofmanydifferentcircuitelements,interconnectsandconnectors

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ApplicationsforPrintedRF/MicrowaveElectronics

• DefenseApplications• Lowcost,flexibleradarsystems

• Anythingthat’swireless (withanAntenna)• IoT

• 5GCellPhones• 30GHz,64elementantennaarrays

• MedicalDevices• Smartdrugdeliverysystems

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PEChallengesinRF/MicrowaveApplicationsComplexCircuit/ModuleDesignElectromagneticsimulationratherthanconventionallumpedelementmodeling

IntegrationofActiveElectronicsNeedtointegratehighperformanceICsandprintedCPWinterconnects

HighFrequencyInterconnectsNeedcontrolledimpedanceinterconnects,reduceparasitics.Surfaceroughnessmatters

SubstrateandInkDevelopmentPlasticfilmsnotdevelopedforelectronicsproperties.Surfacefinish,dielectricpropertiesneedtobecontrolled

MaterialCharacterizationDielectricpropertiesneededathighfrequencies.Mechanical,thermalpropertiesofprintedmaterialsandinks

ThermalManagementNewsubstratematerialswillchallengethermalmanagement– particularlyinhighpowerapplications

ConnectorsIfthegoalistochangetheformfactor(e.g.,flexible)whyusestandardconnectors?

TunabilityReconfigurablecomponentstomaximizeperformancesuchasphased-arrayantennas

Coplanar Waveguide (CPW)

Printed metasurfaceantenna with SMA

connector5

RURI/PERCInitiative:What&Why• ResearchFocus:PrintedElectronics(PE)&AdditiveManufacturing(AM)

• FocusonwirelessandRF/microwaveapplications• Materials,processes,devices,characterization,integratedmodeling• 2Dand3D,flexible,conformableformfactors• InitialfocusonDoDapplicationsbutexpandingtocommercialapplications

• Design,fabricateandcharacterizematerialsandprototypedevicesquickly• Acceleratesproductdesign,designerscantakemorerisk

• CorporatepartnershipsonsponsoredresearchprojectsrelatedtoAM/PE• DevelopthesupplychainforPrintedElectronics• Pursuecorporate,stateandfederalandfundingopportunities• Leverageuniversityinfrastructureandexpertise

• Plasticsengineering,nanomanufacturing• TalentAcquisition

• TrainthenextgenerationofengineersinAMandPE6

PEResearchThroughCorporate/AcademicPartnerships

• PrintedElectronicsResearchCollaborative(PERC)• PERChasraisedover$6.7Mincorporateandfederalfunds• Prepositionteamsforfederalfundingopportunities• 13companieshavejoinedPERC…morecoming

Changing the form factor and reducing cost for radar systems

Bringing the Supply Chain Together to Speed Innovation and Adoption7

• Raytheon-UMassLowellResearchInstitute(RURI)• Newco-locationmodelforuniversity-industrycollaboration• Raytheonemployeeshaveoffices,workwithUMLfaculty,students• ProjectssupportedfrominternalR&Dfunds• Significantpartnershipsinfederalfunding

DevelopingthePrintedElectronicsSupplyChainSystems

PhasedArrayAntennas

FrequencySelectiveSurfaces

SubsystemsAM-Based

PrintedCircuitBoards

PrintedTransistors

AntennasComponents MetamaterialBasedDevices

ThinICswithPrinted

Interconnects

ThermallyConductive

Inks

PrintableMaterials

ElectricallyConductive

InksDielectrics

CNTs&graphene

FlexiblelowlossSubstrates

Ferroelectricmaterials

ProcessingEquipment

Functionalinkprinters-2D

3Dstructuralprinters

Functionalinkprintersfor3D

objects

Optical&thermalsintering

Pick&Placediemountingonflexsubstrates

Modeling&DesignforAM

EMagDesign&simulation

Softwarefor2Dto3D

circuitlayout

ModelingToolIntegration;

Structural,EMag,thermal…

Materialsmodeling&engineering

FlexiblePhasedArrayRadar

PERC/RURI has been visited by over 90 companies and organizations 8

RapidPrototypingUsingPrintedElectronicsDesignandSimulation

MaterialDevelopment BST

2D/3DPrinting&Processes

RF/MicrowaveCharacterization

RURI/PERChascapabilitiesforallpartsofthedevelopment

cycle

Design iterations for additive processes measured in days not months 9

ExtensivePrintedElectronicsCapabilities• PrintingLab

• Optomec AerosolJet• nScrypt Micropen Dispenser

• 4-headandsinglehead• Sonoplot Picoliter Dispenser• Three3Dprinters• PhotonicCuring• KeyenceDigitalMicroscope• 4-pointprobe,profilometer

• ModelingLab• ANSYSMultiphysicsbundle

• MicrowaveTestLab• HPNetworkAnalyzers(20GHzand50GHz)• ThreeWaferProbers• Rhodes&SchwartzSpectrumAnalyzer,VNA

• AntennaCharacterizationLab• Anechoicchamber

• PackagingandSubsystemIntegration• RoboticArmforprintingon3Dobjects

8000sq.ft.- AccessControlsinplacebyfloor,labandofficeforITARProjects 10

4th Floor SaabEmergingTechnologies Building

ResearchProjects§ 2D & 3D Antenna Arrays§ Additive Packaging

– Wirebond replacement– Printed PCBs and via replacement

§ Integrated Printed Connectors§ Tunable Frequency Selective Surfaces§ Polymer-Based Composite Substrates§ Printed Varactors§ Ferroelectric Ink Development§ Printed Phase Shifters§ Hybrid Chip Integration§ Printed CNT Transistors§ Printing on 3D Objects PrintedX-BandVivaldiAntennaArray

PrintedChip Interconnects

PrintedMetasurfaceAntenna

FrequencySelectiveSurface 11

SampleResearchProjects

• Chip/componentintegrationathighfrequencies• Printedinterconnects,wirebond replacements

• Multi-physicsModeling• Integratingelectromagnetic,thermal, structuralmodels

• MaterialCharacterizationatHighFrequencies• Dielectrics,conductivematerials

• NewPrintableMaterialsandtunablemicrowavedevices• Ferroelectricink,printedvaractors,phaseshifters,phasedarrays

• Printed,IntegratedConnectors• Printedconnectorsintegratedwithprintedmodules/PCBs.

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MaterialCharacterization:DielectricConstantvs.Frequency

Films:Free-spacecharacterization3Dprintedapparatusdesignedforholdingpolymerfilms.LensesprintedforfocusingmicrowaveexcitationforS-parametermeasurements

DielectricinkcharacterizationPrintedconcentriccapacitorsdevelopedtoextractdielectricproperties.Easysamplepreparationandsuitableforlowviscositymaterials.

Developednewcharacterizationtechniquesformeasuringthedielectricconstantandlosstangentofnovelcompositepolymersubstratesandinksoverawiderangeoffrequencies.

Solids:WaveguideMethod:DielectricblocksinsertedPLAblocksandsampleinsidetheflange(c)Waveguidemeasurementsetup

5 10 15 20 25 30Frequency (GHz)

0

1

2

3

4

Co

mp

lex P

erm

itti

vit

y '"/ '

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• TunabilityisimportantinmanyRF/Microwavesystems– e.g.tunablefrequencyselectivesurfaces(FSS)andphaseshiftersforphasedarrayapplications

• Aprintablevariablecapacitor(varactor)fabricatedatlowtemperaturesisneeded• Ferroelectricmaterialsarehightemperatureceramicmaterials• Aprintableferroelectricinkhasbeendeveloped-processedat<200oC

Results§ DielectricconstantcanbevariedwithBSTparticle

size,compositionandloading

§ Highdielectricconstantscanbeachieved(55)

§ Lowlosstangent(~0.0005)measured

§ 10%tunabilityofdielectricconstantupto10GHz-3 -2 -1 0 1 2 3

0

5

10

15

20

25

30Cylindrical varactor

Tuning Field Strength (V/µm)

τ C (%

)

0.5 GHz1 GHz2.5 GHz5 GHz

Tunability

2 4 6 8 10 12 14 16 18 2025

30

35

40

45

50

55

60

Frequency (GHz)

BS

T/C

OC

Die

lect

ric

Co

nst

ant,

εr

Cylindrical Varactors

S3-80% HBS100S4-80% HBS200S5-80% HBS800

BariumStrontiumTitanate(BST)nanoparticlesinPolymerBa0.5Sr0.5TiO3 particles(<100nm)Topas®cyclicolefincopolymer(COC5013)polymer

NewMaterialDevelopment:FerroelectricInk

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Application:TunableFrequencySelectiveSurface(FSS)

RigidPCB-basedFSSwithsurfacemountedvaractor diodesbetweenelements.Thisapproachislaborintensiveandnotscalabletolargeareas

Afrequency-selectivesurface (FSS)isanelectromagneticfilter. It’sfrequencyofoperationisdeterminedbythevalueofcouplingcapacitancebetweenelements.Thefrequencyresponsecanbemadetunable byusingvaractors (variablecapacitors)betweencircuitelements.

Surface mount varactor

Flexible,tunableFSSprintedonKapton withprintedvaractorsbetweenelements

Printed varactor15

7 8 9 10 11 12 13-25

-20

-15

-10

-5

0

Frequency (GHz)

|S1

1| (d

B)

Measured:εr=1Measured:εr=6Simulated:εr=1Simulated:εr=6

PrintedPhasedArrayAntennas• Modelledarraybeamsteering• Printantennasandphaseshiftersonflexiblesubstrate• Phaseshiftersenabledthroughuseofferroelectricink• AdjustphaseshiftbyapplyingDCbiasacrossprintedphaseshifter• Microstrip LeftHandTransmissionLine(LHTL)withRadialStub(virtualgrounds)

PrintedPhaseShifter

Modelled array beam steering Array design including Phase Shifters Printed Phased Array on Kapton

NovelFerroelectricInkEnablesanAll-PrintedPhasedArray 16

Additive Packaging: Printed Chip Interconnects• Additively write conductive interconnects between transmission

lines and microchips to replace ribbon and wire bonds.• Issues with inductance of wire & ribbon bonds.• Uncontrolled impedance.• Problems fitting large bonding tool in small areas to form bonds in microwave devices.

• This requires a multiphysics approach:• Dielectric ink used to print the interconnects on top of must be able to function electrically, thermally and

structurally to maintain the integrity of the components surrounding the material

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IntegratedDesignToolsforPrintedInterconnects

ElectromagneticModels(HFSS)•Frequencysweepsof deviceperformance•Optimizechoiceofmaterials•ImportantresultsincludeSparametersandvisualizationofEandHfields

SteadyStateThermal•ResultsfromHFSSareappliedtoconducttemperatureanalysis•Thermalconductivityandothermaterialpropertiesofmaterialsareusedtogenerate‘heatmap’ofdevice,showingtemperatureandheatfluximages

StaticStructural•Stresscausedbythermalexpansion•Thermalexpansioncoefficient,Young’smodulusandothermaterialpropertiesusedtoshowwherethemoststressisappliedtodevice under heated conditions

Designtoolsshouldenableintegrationofelectromagnetic,thermalandstructuralmodels

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MeasuredRibbonBondsvsPrintedInterconnectsThefrequencyresponseofmodelledandmeasuredribbonbondscomparedwithprintedinterconnects.RibbonbondInterconnectsbetweenacoplanarwaveguide(CPW)onaluminaandGaAsmicrochip.

• Verygoodcorrelationofmicrowavemeasurementsbetweenprintedandribbonbondinterconnects

• Simulatedresultsingoodagreementwithmeasuredresults.

PrintedInterconnectsshowpromisingperformanceuptoX-Band

Additive PCBs and Connectors• ConnectorsandsmallPCBscanbeprintedinahybridsystem(thermoplasticsandconductivetraces).Connectorsemployprintedmechanicalfeaturestoalignconductivetraces.

• PCBscanbeprintedwithintegratedconnectors

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3DAdditiveRFSystems:LowCostX-BandAntennaArrays

VivaldiAntennaArray

LNAelectronics

• Focusonlowcostapproachesforbroadbandantennas• VivaldiantennadesignatX-Band• ThermoplasticsprintingtocreatephysicalscaffoldingforVivaldiantennaarray• Developingchipattachandprintedinterconnectonthermoplastics

Printedconductivetraceon3D-printedsurface

Surfacesnotflatenoughforfineconductivetraces

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FinalThoughts• PrintedElectronicsformicrowaveapplicationsisinthe“WildWest”phase

• Incoherentsupplychain• Lackofstandards,materials,models,SW• Developmentofprintedsubsystemsinthemicrowavedomainintroduces

additionalchallengesineveryphase(design,materials,printing&characterization)

• WillneedtodevelopthesupplychainforPEtechnologysimilartoICmanufacturersinthe60’s&70’s

• Partnershipsbetweencompanies,government(stateandfederal)anduniversitiescanacceleratethebuildoutoftheecosystemforprintedelectronics

RURIandPERCbringindustry,academiaandsupplychaintogethertoaccelerateinnovationandadoptionofprintedelectronicsformicrowaveapplications.

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PEFormFactorsandPrintingTechnology

Flex-HybridsystemsaddactivecomponentsAerosoljetprinters

2.5D

Flexible,conformablePlasticorpapersubstrates

Micropen Dispensers

2D

Multipletypesofprintingsystemsmayberequireddependingontheformfactor,printedfeaturessizes,andthematerialsrequiredtobuildthedevice/system Printelectronicsonexisting3Dstructures

MicropenwithsurfacemappingORRoboticarm

Printing3D

Print3DstructureswithelectronicsMultipleprinters(3D+aerosol)OR

Hybrid(multihead)system

Printingon3D

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