Intel E6700 Mechanical Design Guidelines - Page 27

Thermal Metrology

Thermal and Mechanical Design Guidelines

27

Assume the TDP, as listed in the datasheet, is 100 W and the maximum case

temperature from the thermal profile for 100 W is 67 °C. Assume as well that the

system airflow has been designed such that the local ambient temperature is 38 °C.

Then, the following could be calculated using equation 1 from above:

Ψ

CA

= (T

C,

−

T

A

) / TDP = (67 – 38) / 100 = 0.29 °C/W

To determine the required heatsink performance, a heatsink solution provider would

need to determine

Ψ

CS

performance for the selected TIM and mechanical load

configuration. If the heatsink solution were designed to work with a TIM material

performing at

Ψ

CS

≤

0.10 °C/W, solving for equation 2 from above, the performance of

the heatsink would be:

Ψ

SA

=

Ψ

CA

−

Ψ

CS

= 0.29

−

0.10 = 0.19 °C/W

3.2

Processor Thermal Solution Performance

Assessment

Thermal performance of a heatsink should be assessed using a thermal test vehicle

(TTV) provided by Intel. The TTV is a stable heat source that the user can make

accurate power measurement, whereas processors can introduce additional factors

that can impact test results. In particular, the power level from actual processors

varies significantly, even when running the maximum power application provided by

Intel, due to variances in the manufacturing process. The TTV provides consistent

power and power density for thermal solution characterization and results can be

easily translated to real processor performance. Accurate measurement of the power

dissipated by an actual processor is beyond the scope of this document.

Once the thermal solution is designed and validated with the TTV, it is strongly

recommended to verify functionality of the thermal solution on real processors and on

fully integrated systems. The Intel maximum power application enables steady power

dissipation on a processor to assist in this testing. This maximum power application is

provided by Intel.

3.3

Local Ambient Temperature Measurement

Guidelines

The local ambient temperature T

A

is the temperature of the ambient air surrounding

the processor. For a passive heatsink, T

A

is defined as the heatsink approach air

temperature; for an actively cooled heatsink, it is the temperature of inlet air to the

active cooling fan.

It is worthwhile to determine the local ambient temperature in the chassis around the

processor to understand the effect it may have on the case temperature.

T

A

is best measured by averaging temperature measurements at multiple locations in

the heatsink inlet airflow. This method helps reduce error and eliminate minor spatial

variations in temperature. The following guidelines are meant to enable accurate

determination of the localized air temperature around the processor during system

thermal testing.

Section	Page
1 Introduction	9
1.1 Document Goals and Scope	9
1.1.1 Importance of Thermal Management	9
1.1.2 Document Goals	9
1.1.3 Document Scope	10
1.2 References	11
1.3 Definition of Terms	11
2 Processor Thermal/Mechanical Information	13
2.1 Mechanical Requirements	13
2.1.1 Processor Package	13
2.1.2 Heatsink Attach	15
2.1.2.1 General Guidelines	15
2.1.2.2 Heatsink Clip Load Requirement	15
2.1.2.3 Additional Guidelines	16
2.2 Thermal Requirements	16
2.2.1 Processor Case Temperature	16
2.2.2 Thermal Profile	17
2.2.3 Thermal Solution Design Requirements	17
2.2.4 TCONTROL	18
2.3 Heatsink Design Considerations	19
2.3.1 Heatsink Size	20
2.3.2 Heatsink Mass	20
2.3.3 Package IHS Flatness	21
2.3.4 Thermal Interface Material	21
2.4 System Thermal Solution Considerations	22
2.4.1 Chassis Thermal Design Capabilities	22
2.4.2 Improving Chassis Thermal Performance	22
2.4.3 Summary	23
2.5 System Integration Considerations	23
3 Thermal Metrology	25
3.1 Characterizing Cooling Performance Requirements	25
3.1.1 Example	26
3.2 Processor Thermal Solution Performance Assessment	27
3.3 Local Ambient Temperature Measurement Guidelines	27
3.4 Processor Case Temperature Measurement Guidelines	30
4 Thermal Management Logic and Thermal Monitor Feature	31
4.1 Processor Power Dissipation	31
4.2 Thermal Monitor Implementation	31
4.2.1 PROCHOT# Signal	32
4.2.2 Thermal Control Circuit	32
4.2.2.1 Thermal Monitor	32
4.2.3 Thermal Monitor 2	33
4.2.4 Operation and Configuration	34
4.2.5 On-Demand Mode	35
4.2.6 System Considerations	35
4.2.7 Operating System and Application Software Considerations	36
4.2.8 THERMTRIP# Signal	36
4.2.9 Cooling System Failure Warning	36
4.2.10 Digital Thermal Sensor	37
4.2.11 Platform Environmental Control Interface (PECI)	38
5 Balanced Technology Extended (BTX) Thermal/Mechanical Design Information	39
5.1 Overview of the BTX Reference Design	39
5.1.1 Target Heatsink Performance	39
5.1.2 Acoustics	40
5.1.3 Effective Fan Curve	41
5.1.4 Voltage Regulator Thermal Management	42
5.1.5 Altitude	43
5.1.6 Reference Heatsink Thermal Validation	43
5.2 Environmental Reliability Testing	43
5.2.1 Structural Reliability Testing	43
5.2.1.1 Random Vibration Test Procedure	43
5.2.1.2 Shock Test Procedure	44
5.2.2 Power Cycling	45
5.2.3 Recommended BIOS/CPU/Memory Test Procedures	46
5.3 Material and Recycling Requirements	46
5.4 Safety Requirements	47
5.5 Geometric Envelope for Intel® Reference BTX Thermal Module Assembly	47
5.6 Preload and TMA Stiffness	48
5.6.1 Structural Design Strategy	48
5.6.2 TMA Preload verse Stiffness	48
6 ATX Thermal/Mechanical Design Information	51
6.1 ATX Reference Design Requirements	51
6.2 Validation Results for Reference Design	53
6.2.1 Heatsink Performance	53
6.2.2 Acoustics	54
6.2.3 Altitude	54
6.2.4 Heatsink Thermal Validation	55
6.3 Environmental Reliability Testing	55
6.3.1 Structural Reliability Testing	55
6.3.1.1 Random Vibration Test Procedure	55
6.3.1.2 Shock Test Procedure	56
6.3.2 Power Cycling	57
6.3.3 Recommended BIOS/CPU/Memory Test Procedures	58
6.4 Material and Recycling Requirements	58
6.5 Safety Requirements	59
6.6 Geometric Envelope for Intel® Reference ATX Thermal Mechanical Design	59
6.7 Reference Attach Mechanism	60
6.7.1 Structural Design Strategy	60
6.7.2 Mechanical Interface to the Reference Attach Mechanism	61
7 Intel® Quiet System Technology (Intel® QST)	63
7.1 Intel® QST Algorithm	63
7.1.1 Output Weighting Matrix	64
7.1.2 Proportional-Integral-Derivative (PID)	64
7.2 Board and System Implementation of Intel® QST	66
7.3 Intel® QST Configuration and Tuning	68

Intel E6700 Mechanical Design Guidelines - Page 27

Processor Thermal Solution Performance, Assessment, Local Ambient Temperature Measurement,

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