Intel QX9770 Design Guidelines - Page 15

Processor Thermal/Mechanical Information

Thermal and Mechanical Design Guidelines

15

2.1.2

Heatsink Attach

2.1.2.1

General Guidelines

There are no features on the LGA775 socket to directly attach a heatsink: a

mechanism must be designed to attach the heatsink directly to the motherboard.

In

addition to holding the heatsink in place on top of the IHS, this mechanism plays a

significant role in the robustness of the system in which it is implemented, in

particular:

•

Ensuring thermal performance of the thermal interface material (TIM) applied

between the IHS and the heatsink.

TIMs based on phase change materials are

very sensitive to applied pressure: the higher the pressure, the better the initial

performance.

TIMs, such as thermal greases, are not as sensitive to applied

pressure.

Designs should consider a possible decrease in applied pressure over

time due to potential structural relaxation in retention components.

•

Ensuring system electrical, thermal, and structural integrity under shock and

vibration events.

The mechanical requirements of the heatsink attach mechanism

depend on the mass of the heatsink and the level of shock and vibration that the

system must support.

The overall structural design of the motherboard and the

system have to be considered when designing the heatsink attach mechanism.

Their design should provide a means for protecting LGA775 socket solder joints.

The Intel ALCT reference design attach mechanism described in Section.

5.6

Note:

Package pull-out during mechanical shock and vibration is constrained by the LGA775

socket load plate (refer to the

LGA775 Socket Mechanical Design Guide

for further

information).

2.1.2.2

The Pump Assembly Clip Load Requirement

The attach mechanism for the pump assembly developed to support the processor

should create a static preload on the package between

18 lbf

and

70 lbf

throughout

the life of the product for designs compliant with the Intel reference design

assumptions:

•

72 mm x 72 mm mounting hole span (refer to Figure 66)

The minimum load is required to protect against fatigue failure of socket solder joint in

temperature cycling.

It is important to take into account potential load degradation from creep over time

when designing the pump assembly clip to the required minimum load. This means

the initial preload at beginning of life of the product may be significantly higher than

the minimum preload that must be met throughout the life of the product. For

additional guidelines on mechanical design, in particular on designs departing from the

reference design assumptions, refer to

Appendix A.

For clip load metrology guidelines, refer to

Appendix B.

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 The Pump Assembly 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 TCONTROL	18
2.3 Heatsink Design Considerations	19
2.3.1 Heatsink Size	20
2.3.2 Package IHS Flatness	20
2.3.3 Thermal Interface Material	21
2.4 System Thermal Solution Considerations	21
2.4.1 Chassis Thermal Design Capabilities	21
2.4.2 Improving Chassis Thermal Performance	21
2.4.3 Summary	22
2.5 System Integration Considerations	22
3 Thermal Metrology	23
3.1 Characterizing Cooling Performance Requirements	23
3.1.1 Example	25
3.2 Processor Thermal Solution Performance Assessment	26
3.3 Local Ambient Temperature Measurement Guidelines	26
3.4 Processor Case Temperature Measurement Guidelines	29
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
4.2.3 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 Intel Thermal/Mechanical Reference Design Information	39
5.1 Validation Results for the ATX Reference Design	39
5.1.1 Heatsink Performance	40
5.1.2 Acoustics	40
5.1.3 Altitude	41
5.1.4 Reference Heatsink Thermal Validation	41
5.1.5 Fan Motor Performance	42
5.1.6 Pump Motor Performance	43
5.2 Environmental Reliability Testing	44
5.2.1 Structural Reliability Testing	44
5.2.1.1 Random Vibration Test Procedure	44
5.2.1.2 Shock Test Procedure	45
5.2.2 Power Cycling	46
5.2.3 Reliability Testing	46
5.2.3.1 Tubing Material Selection	48
5.2.3.2 Reservoir Sizing	48
5.2.3.3 Reliability Test Results	50
5.2.4 Recommended BIOS/CPU/Memory Test Procedures	51
5.3 Material and Recycling Requirements	52
5.4 Safety Requirements	52
5.5 Geometric Envelope for Intel Reference ATX Thermal Mechanical Design	52
5.6 Reference Attach Mechanism	54
5.7 Socket and Voltage Regulation Cooling Strategy	55
6 Intel® Quiet System Technology (Intel® QST)	57
6.1 Intel® Quiet System Technology Algorithm	57
6.1.1 Output Weighting Matrix	58
6.1.2 Proportional-Integral-Derivative (PID)	58
6.2 Board and System Implementation of Intel® Quiet System Technology	60
6.3 Intel® QST Configuration & Tuning	62

Intel QX9770 Design Guidelines - Page 15

Heatsink Attach, 2.1.2.1 General Guidelines, 2.1.2.2 The Pump Assembly Clip Load Requirement

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