Intel 5400 Series manual Thermal/Mechanical Reference Design Considerations, Heatsink Solutions

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Thermal/Mechanical Reference Design

To develop a reliable, cost-effective thermal solution, thermal characterization and simulation should be carried out at the entire system level, accounting for the thermal requirements of each component. In addition, acoustic noise constraints may limit the size, number, placement, and types of fans that can be used in a particular design.

2.5Thermal/Mechanical Reference Design Considerations

2.5.1Heatsink Solutions

2.5.1.1Heatsink Design Considerations

To remove the heat from the processor, three basic parameters should be considered:

•The area of the surface on which the heat transfer takes place - Without any enhancements, this is the surface of the processor package IHS. One method used to improve thermal performance is by attaching a heatsink to the IHS. A heatsink can increase the effective heat transfer surface area by conducting heat out of the IHS and into the surrounding air through fins attached to the heatsink base.

•The conduction path from the heat source to the heatsink fins - Providing a direct conduction path from the heat source to the heatsink fins and selecting materials with higher thermal conductivity typically improves heatsink performance. The length, thickness, and conductivity of the conduction path from the heat source to the fins directly impact the thermal performance of the heatsink. In particular, the quality of the contact between the package IHS and the heatsink base has a higher impact on the overall thermal solution performance as processor cooling requirements become strict. Thermal interface material (TIM) is used to fill in the gap between the IHS and the bottom surface of the heatsink, and thereby improves the overall performance of the thermal stackup (IHS-TIM-Heatsink). With extremely poor heatsink interface flatness or roughness, TIM may not adequately fill the gap. The TIM thermal performance depends on its thermal conductivity as well as the pressure load applied to it. Refer to Section 2.5.2 for further information on the TIM between the IHS and the heatsink base.

•The heat transfer conditions on the surface on which heat transfer takes place - Convective heat transfer occurs between the airflow and the surface exposed to the flow. It is characterized by the local ambient temperature of the air,

TLA, and the local air velocity over the surface. The higher the air velocity over the surface, the resulting cooling is more efficient. The nature of the airflow can also enhance heat transfer via convection. Turbulent flow can provide improvement over laminar flow. In the case of a heatsink, the surface exposed to the flow includes the fin faces and the heatsink base.

An active heatsink typically incorporates a fan that helps manage the airflow through the heatsink.

Passive heatsink solutions require in-depth knowledge of the airflow in the chassis. Typically, passive heatsinks see slower air speed. Therefore, these heatsinks are typically larger (and heavier) than active heatsinks due to the increase in fin surface required to meet a required performance. As the heatsink fin density (the number of fins in a given cross-section) increases, the resistance to the airflow increases: it is more likely that the air will travel around the heatsink instead of through it, unless air bypass is carefully managed. Using air-ducting techniques to manage bypass area is an effective method for maximizing airflow through the heatsink fins.

Quad-Core Intel® Xeon® Processor 5400 Series TMDG

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Contents Thermal/Mechanical Design Guidelines Quad-Core Intel Xeon Processor 5400 SeriesQuad-Core Intel Xeon Processor 5400 Series Tmdg Contents Figures Preload Test Configuration Tables Initial release of the document Reference Revision Description Date NumberQuad-Core Intel Xeon Processor 5400 Series Tmdg Scope ObjectiveReferences Terms and Descriptions Sheet 1 Definition of TermsTerm Description TDP Terms and Descriptions Sheet 2Introduction Processor Mechanical Parameters Mechanical RequirementsProcessor Mechanical Parameters Table Parameter Minimum Maximum UnitQuad-Core Intel Xeon Processor 5400 Series Package Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design Quad-Core Intel Xeon Processor 5400 Series Considerations Thermal Control Circuit and TDP Processor Thermal Parameters and FeaturesDigital Thermal Sensor Multiple Core Special Considerations Platform Environmental Control Interface PeciMultiple Digital Thermal Sensor Operation PROCHOT#, THERMTRIP#, and FORCEPR# Thermal Monitor for Multiple Core ProductsHeatpipe Orientation for Multiple Core Processors Processor Input Processor OutputFeature Dimension Processor Core Geometric Center DimensionsEquation 2-1.y = ax + b Thermal ProfileEquation 2-2.TCONTROL= -TOFFSET Tcontrol DefinitionTcontrol and Thermal Profile Interaction Thermal Profile B Performance Targets Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design 2U+ CEK, Thermal Profile a Parameter Maximum Unit1U CEK, Thermal Profile B Sea-Level Fan Fail Guidelines1U Alternative Heatsink Fan Speed Control Characterizing Cooling Solution Performance RequirementsFan Speed Control, Tcontrol and DTS Relationship Processor Thermal Characterization Parameter RelationshipsEquation 2-3.ΨCA= Tcase TLA / TDP Condition FSC SchemeEquation 2-4.ΨCA= ΨCS + ΨSA ExampleChassis Thermal Design Capabilities and Improvements Chassis Thermal Design ConsiderationsEquation 2-5.ΨCA= Tcase TLA / TDP = 68 45 / 85 = 0.27 C/W Equation 2-6.ΨSA= ΨCA − ΨCS = 0.27 − 0.05 = 0.22 C/WThermal/Mechanical Reference Design Considerations Heatsink SolutionsHeatsink Design Considerations Summary Thermal Interface MaterialGeometric Envelope Assembly DrawingStructural Considerations of CEK 17 U+ CEK Heatsink Thermal Performance Thermal Solution Performance CharacteristicsEquation 2-8.y = 0.187*X + Thermal Profile AdherenceEquation 2-9.y = 0.246*X + =0.187* X +40Equation 2-10.y = 0.246*X + 1UCEKReference SolutionHeatsink with Captive Screws and Standoffs Components Overview22. Isometric View of the 2U+ CEK Heatsink Recommended Thermal Grease Dispense Weight CEK Heatsink Thermal Mechanical CharacteristicsThermal Interface Material TIM Processor Minimum Maximum Units24. CEK Spring Isometric View CEK SpringThermal/Mechanical Reference Design Fan Specifications Boxed 4-wire PWM/DTS Heatsink Solution Fan Power SupplyDescription Min Typ Max Unit Steady Startup Systems Considerations Associated with the Active CEK Boxed Processor ContentsThermal/Mechanical Reference Design Figure A-1. Isometric View of the 1U Alternative Heatsink Component OverviewThermal Profile Adherence Thermal Solution Performance CharactericsEquation A-1. y = 0.331*x + = Processor power value W 1U Alternative Heatsink Thermal/Mechanical Design Drawing Description Table B-1. Mechanical Drawing ListFigure B-1 2U CEK Heatsink Sheet 1 Figure B-2 2U CEK Heatsink Sheet 2 Figure B-3 U CEK Heatsink Sheet 3 Figure B-4 2U CEK Heatsink Sheet 4 Figure B-5. CEK Spring Sheet 1 Figure B-6. CEK Spring Sheet 2 Figure B-7. CEK Spring Sheet 3 Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Figure B-14 U CEK Heatsink Sheet 1 Figure B-15 U CEK Heatsink Sheet 2 Figure B-16 U CEK Heatsink Sheet 3 Figure B-17 U CEK Heatsink Sheet 4 Figure B-18. Active CEK Thermal Solution Volumetric Sheet 1 Figure B-19. Active CEK Thermal Solution Volumetric Sheet 2 Figure B-20. Active CEK Thermal Solution Volumetric Sheet 3 Figure B-21 U Alternative Heatsink 1 Figure B-22 U Alternative Heatsink 2 Figure B-23 U Alternative Heatsink 3 Figure B-24 U Alternative Heatsink 4 Mechanical Drawings Test Preparation OverviewHeatsink Preparation Alternate Heatsink Sample Preparation Figure C-3. Preload Test Configuration Time-Zero, Room Temperature Preload Measurement Test Procedure ExamplesTypical Test Equipment Table C-1. Typical Test EquipmentPreload Degradation under Bake Conditions Heatsink Clip Load Methodology Safety Requirements Safety Requirements Structural Reliability Testing Environmental Reliability TestingIntel Verification Criteria for the Reference Designs Reference Heatsink Thermal VerificationPost-Test Pass Criteria 2.2 Recommended Test SequenceTable E-1 Use Conditions Environment Material and Recycling Requirements Recommended BIOS/Processor/Memory Test ProceduresQuality and Reliability Requirements Supplier Information Intel Enabled SuppliersFor 1U Additional Suppliers2U Heatsink Alternative CEK Copper Fin Alternative CEK Copper Fin Enabled Suppliers Information 100 Quad-Core Intel Xeon Processor 5400 Series Tmdg
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