Intel 5400 Series manual Chassis Thermal Design Considerations

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Thermal/Mechanical Reference Design

Assume the datasheet TDP is 85 W and the case temperature specification is 68 °C. Assume as well that the system airflow has been designed such that the local processor ambient temperature is 45°C. Then the following could be calculated using equation (2-3) from above:

Equation 2-5.ΨCA= (TCASE – TLA) / TDP = (68 – 45) / 85 = 0.27 °C/W

To determine the required heatsink performance, a heatsink solution provider would need to determine ΨCS performance for the selected TIM and mechanical load configuration. If the heatsink solution was designed to work with a TIM material performing at ΨCS ≤ 0.05 °C/W, solving for equation (2-4) from above, the performance of the heatsink would be:

Equation 2-6.ΨSA= ΨCA − ΨCS = 0.27 − 0.05 = 0.22 °C/W

If the local processor ambient temperature is assumed to be 40°C, the same calculation can be carried out to determine the new case-to-ambient thermal resistance:

Equation 2-7.ΨCA= (TCASE – TLA) / TDP = (68 – 40) / 85 = 0.33 °C/W

It is evident from the above calculations that, a reduction in the local processor ambient temperature has a significant positive effect on the case-to-ambient thermal resistance requirement.

2.4.3Chassis Thermal Design Considerations

2.4.3.1Chassis Thermal Design Capabilities and Improvements

One of the critical parameters in thermal design is the local ambient temperature assumption of the processor. Keeping the external chassis temperature fixed, internal chassis temperature rise is the only component that can affect the processor local ambient temperature. Every degree gained at the local ambient temperature directly translates into a degree relief in the processor case temperature.

Given the thermal targets for the processor, it is extremely important to optimize the

chassis design to minimize the air temperature rise upstream to the processor (Trise), hence minimizing the processor local ambient temperature.

The heat generated by components within the chassis must be removed to provide an adequate operating environment for both the processor and other system components. Moving air through the chassis brings in air from the external ambient environment and transports the heat generated by the processor and other system components out of the system. The number, size and relative position of fans, vents and other heat generating components determine the chassis thermal performance, and the resulting ambient temperature around the processor. The size and type (passive or active) of the thermal solution and the amount of system airflow can be traded off against each other to meet specific system design constraints. Additional constraints are board layout, spacing, component placement, and structural considerations that limit the thermal solution size.

In addition to passive heatsinks, fan heatsinks and system fans, other solutions exist for cooling integrated circuit devices. For example, ducted blowers, heat pipes and liquid cooling are all capable of dissipating additional heat. Due to their varying attributes, each of these solutions may be appropriate for a particular system implementation.

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Quad-Core Intel® Xeon® Processor 5400 Series TMDG

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Contents Quad-Core Intel Xeon Processor 5400 Series Thermal/Mechanical Design GuidelinesQuad-Core Intel Xeon Processor 5400 Series Tmdg Contents Figures Preload Test Configuration Tables Reference Revision Description Date Number Initial release of the documentQuad-Core Intel Xeon Processor 5400 Series Tmdg Objective ScopeReferences Definition of Terms Terms and Descriptions Sheet 1Term Description Terms and Descriptions Sheet 2 TDPIntroduction Mechanical Requirements Processor Mechanical ParametersProcessor 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 Processor Thermal Parameters and Features Thermal Control Circuit and TDPDigital Thermal Sensor Platform Environmental Control Interface Peci Multiple Core Special ConsiderationsMultiple Digital Thermal Sensor Operation Thermal Monitor for Multiple Core Products PROCHOT#, THERMTRIP#, and FORCEPR#Heatpipe Orientation for Multiple Core Processors Processor Input Processor OutputProcessor Core Geometric Center Dimensions Feature DimensionThermal Profile Equation 2-1.y = ax + bTcontrol Definition Equation 2-2.TCONTROL= -TOFFSETTcontrol and Thermal Profile Interaction Thermal Profile B Performance Targets Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design Parameter Maximum Unit 2U+ CEK, Thermal Profile a1U CEK, Thermal Profile B Fan Fail Guidelines Sea-Level1U Alternative Heatsink Characterizing Cooling Solution Performance Requirements Fan Speed ControlProcessor Thermal Characterization Parameter Relationships Fan Speed Control, Tcontrol and DTS RelationshipEquation 2-3.ΨCA= Tcase TLA / TDP Condition FSC SchemeExample Equation 2-4.ΨCA= ΨCS + ΨSAChassis Thermal Design Considerations Chassis Thermal Design Capabilities and ImprovementsEquation 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/WHeatsink Solutions Thermal/Mechanical Reference Design ConsiderationsHeatsink Design Considerations Thermal Interface Material SummaryAssembly Drawing Geometric EnvelopeStructural Considerations of CEK Thermal Solution Performance Characteristics 17 U+ CEK Heatsink Thermal PerformanceThermal Profile Adherence Equation 2-8.y = 0.187*X +=0.187* X +40 Equation 2-9.y = 0.246*X +1UCEKReference Solution Equation 2-10.y = 0.246*X +Components Overview Heatsink with Captive Screws and Standoffs22. Isometric View of the 2U+ CEK Heatsink CEK Heatsink Thermal Mechanical Characteristics Recommended Thermal Grease Dispense WeightThermal Interface Material TIM Processor Minimum Maximum UnitsCEK Spring 24. CEK Spring Isometric ViewThermal/Mechanical Reference Design Fan Power Supply Fan Specifications Boxed 4-wire PWM/DTS Heatsink SolutionDescription Min Typ Max Unit Steady Startup Boxed Processor Contents Systems Considerations Associated with the Active CEKThermal/Mechanical Reference Design Component Overview Figure A-1. Isometric View of the 1U Alternative HeatsinkThermal Solution Performance Characterics Thermal Profile AdherenceEquation A-1. y = 0.331*x + = Processor power value W 1U Alternative Heatsink Thermal/Mechanical Design Table B-1. Mechanical Drawing List Drawing DescriptionFigure 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 Overview Test PreparationHeatsink Preparation Alternate Heatsink Sample Preparation Figure C-3. Preload Test Configuration Test Procedure Examples Time-Zero, Room Temperature Preload MeasurementTypical Test Equipment Table C-1. Typical Test EquipmentPreload Degradation under Bake Conditions Heatsink Clip Load Methodology Safety Requirements Safety Requirements Environmental Reliability Testing Structural Reliability TestingIntel Verification Criteria for the Reference Designs Reference Heatsink Thermal Verification2.2 Recommended Test Sequence Post-Test Pass CriteriaTable E-1 Use Conditions Environment Recommended BIOS/Processor/Memory Test Procedures Material and Recycling RequirementsQuality and Reliability Requirements Intel Enabled Suppliers Supplier InformationAdditional Suppliers For 1U2U 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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