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
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 22
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
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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
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1414
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
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1616
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””))
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1717
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
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1818
Next StepsNext Steps
Complete TTV environ. testsComplete TTV environ. testsReduce voids to <2%Reduce voids to <2%Further customer qualificationFurther customer qualificationTIM2 developmentTIM2 development
October 25, 2005October 25, 2005 ©© 2005 Enerdyne Solutions2005 Enerdyne Solutions Page Page 1919
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 [email protected]