Processor Performance, Packaging and Reliability Utilizing a Phase Change Metallic

Alloy Thermal Interface SystemC. Macris, C. Leyerle, T. Sanderson, R. EbelC. Macris, C. Leyerle, T. Sanderson, R. Ebel

Enerdyne Solutions Enerdyne Solutions www.enerdynesolutions.comwww.enerdynesolutions.com

Presented at the 2005 IMAPS Advanced Technology Workshop on Thermal Management Dinah’s Garden Hotel, Palo Alto CA USA

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OutlineOutlineTestingTestingPerformance DataPerformance DataPackaging & ReliabilityPackaging & ReliabilityNext StepsNext StepsSummarySummary

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TestingTestingOverviewOverview

TIM1 interface testedTIM1 interface testedThermal Test Vehicles (TTVs)Thermal Test Vehicles (TTVs)ΘΘjcjc calculated calculated Comparative dataComparative data

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TestingTestingThermal Test Vehicles (TTVs)Thermal Test Vehicles (TTVs)

1.4 cm1.4 cm22 die areadie area80 Watts80 WattsUniform heat flux Uniform heat flux (57 W/cm(57 W/cm22))FCPGA packageFCPGA packageNiNi--plated Cu lidplated Cu lid

October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 55

TestingTestingValue of TTV TestingValue of TTV Testing

Actual chip and lid surface finish, Actual chip and lid surface finish, flatness and compositionflatness and compositionSimulate processor hot spotsSimulate processor hot spotsTest lid attach process qualitiesTest lid attach process qualitiesAssemblies can be environmentally Assemblies can be environmentally stressed without disturbing interfacestressed without disturbing interface

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8080

0.070.07--0.080.08(8(8--9 mil 9 mil

BLTBLT))

156156

IndiumIndium

SolderSolder

IndiumIndiumSolderSolder

> 20> 203.03.06.06.0Conductivity (W/mK)Conductivity (W/mK)

< 0.04< 0.04(80(80°°C, 40 C, 40 psipsi))

0.06250.0625(70(70°°C, 50 C, 50 psipsi))

~ 0.07~ 0.07(1 mil BLT(1 mil BLT ))

ImpedanceImpedance((°°CC--cmcm22/W)/W)

~65~6543 / 6543 / 65N/AN/APhase Change Phase Change Temperature (Temperature (°°C)C)

IndiumIndium--basedbased

PCMA PCMA within within

polymerpolymer

AlAl--filled filled polymerpolymerCompositionComposition

PCMAPCMAPSHPSHGreaseGreaseTIM TypeTIM Type

EnerdyneEnerdyneIndigo1Indigo1

ChomericsChomericsT557T557

ShinShin--EtsuEtsuX23X23--7783D7783D

Extrapolated from BLT vs. impedance graphExtrapolated from BLT vs. impedance graph

TestingTestingTIMsTIMs

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TestingTestingPlatformPlatform

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TestingTestingTTV AssemblyTTV Assembly

10 lbs force10 lbs forceNo lid sealNo lid sealMinimum Minimum BondlineBondline Thickness (BLT)Thickness (BLT)Gold metallization on Indium TTVGold metallization on Indium TTV

TIM1TIM1

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TestingTestingMethodologyMethodology

CalibrationCalibrationBias of dieBias of diePower, diode resistance & case Power, diode resistance & case temperature measuredtemperature measured3 measurements / sample3 measurements / sampleΘΘjcjc calculatedcalculated

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Performance DataPerformance Data

0.249 0.250

0.267

0.189

0.15

0.20

0.25

0.30

0.35

X23 T557 Indium Indigo1

ΘΘjcjc

((00C/W)C/W)

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Packaging & ReliabilityPackaging & ReliabilityHistoric TIM QualitiesHistoric TIM Qualities

Needs AuNeeds Au--plate for plate for wettabilitywettabilityReflow neededReflow neededStress cracking, delaminationStress cracking, delaminationVoidingVoiding

High (metal) bulk conductivityHigh (metal) bulk conductivityEasy handlingEasy handlingNo pumpNo pump--outoutNo migrationNo migration

Indium solderIndium solder

Reflow neededReflow neededPumpPump--outoutMigrationMigrationVoidingVoidingOxidationOxidation

High (metal) bulk conductivityHigh (metal) bulk conductivityEasy handlingEasy handlingReworkableReworkable

PhasePhase--Change Change Metal Alloy Metal Alloy (PCMA)(PCMA)

Cure neededCure neededReflow neededReflow neededDelaminationDelaminationNonNon--reworkablereworkable

Good bulk conductivityGood bulk conductivityConforms to surface Conforms to surface

irregularitiesirregularities

PolymerPolymer--solder solder Hybrid (PSH)Hybrid (PSH)

PumpPump--outoutPhase separationPhase separationMigrationMigration

High bulk conductivityHigh bulk conductivityConforms to surface Conforms to surface

irregularitiesirregularitiesNo cureNo cureReworkableReworkable

Thermal Thermal GreaseGrease

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October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1212

Packaging & ReliabilityPackaging & ReliabilityOverviewOverview

CorrosionCorrosionMigrationMigrationDiffusionDiffusion

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Packaging & ReliabilityPackaging & ReliabilityCorrosionCorrosion MitigationMitigation

VentVent--free continuous lid sealfree continuous lid sealSealant with low vapor Sealant with low vapor transmission ratetransmission rateCompatible with PCMA burnCompatible with PCMA burn--in in during lid attachduring lid attach

PCMA TIM1PCMA TIM1

LID SEALLID SEAL

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Packaging & ReliabilityPackaging & ReliabilityCorrosionCorrosion MitigationMitigation

Lid seal facilitates Lid seal facilitates controlled environ. controlled environ. within lid cavitywithin lid cavityVapor Phase Vapor Phase Corrosion Inhibitor Corrosion Inhibitor (VPCI)(VPCI)VPCI ions on VPCI ions on PCMA surface PCMA surface interrupt corrosion interrupt corrosion cellcell

VPCISource

Metal

CathodeAnode++---- ---------- ++ ++ ++ ++ ++ ++

------ ++++

++DissolvedVPCI ions

Molecules of VPCIin gaseous phase

October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1515

Packaging & ReliabilityPackaging & ReliabilityCorrosionCorrosion MitigationMitigation

Temperature cyclingTemperature cycling——Service Condition Service Condition ““BB””--5555°°C to +125C to +125°°CC

IndigoIndigo

1800 temp cycles1800 temp cycles

PCMA without mitigantsPCMA without mitigants

50 temp cycles50 temp cycles

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Packaging & ReliabilityPackaging & ReliabilityMigration ControlMigration Control

Deployment of perimeter Deployment of perimeter barrierbarrierSecondary containment Secondary containment by lid sealby lid sealPassed shock test Passed shock test (Service Condition (Service Condition ““EE””))Passed vibration test Passed vibration test (Service Condition (Service Condition ““44””))

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Packaging & ReliabilityPackaging & ReliabilityDiffusionDiffusion

<1 nm<1 nm7.23 x 107.23 x 10--6060BismuthBismuth<1 nm<1 nm3.30 x 103.30 x 10--5252IndiumIndium< 1 < 1 µµmm1.50 x 101.50 x 10--1818GoldGold~ 10 ~ 10 µµmm1.22 x 101.22 x 10--1515CopperCopper<1 nm<1 nm4.06 x 104.06 x 10--4747AluminumAluminum

Penetration Penetration Depth after 10 Depth after 10

YearsYears

DD100100°°CC (cm(cm22/sec)/sec)MaterialMaterial

Insufficient energy at typical operating Insufficient energy at typical operating temperatures for measurable diffusiontemperatures for measurable diffusionSignificantly more diffusion of Significantly more diffusion of AuSnAuSnfrom eutectic die bondingfrom eutectic die bonding

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Next StepsNext Steps

Complete TTV environ. testsComplete TTV environ. testsReduce voids to <2%Reduce voids to <2%Further customer qualificationFurther customer qualificationTIM2 developmentTIM2 development

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PCMA Thermal Interface PCMA Thermal Interface SummarySummary

2525--30% reduction of 30% reduction of ΘΘjcjcNo chip metallization required No chip metallization required Corrosion mitigation demonstratedCorrosion mitigation demonstratedMigration controlledMigration controlledNegligible diffusion in Silicon Negligible diffusion in Silicon

October 25, 2005 © 2005 Enerdyne Solutions 20

Thank you.Chris G. Macris

Enerdyne SolutionsP.O. Box 2660

North Bend, WA. 98045-2660

425-888-1880 x302chris@enerdynesolutions.com