Intel E6700 - Core 2 Duo Dual-Core Processor Guide

Document Number: 318734-017
Intel®Core™2 Duo Processor
E8000∆and E7000∆Series, Intel®
Pentium®Dual-Core Processor
E6000∆and E5000∆Series, and
Intel®Celeron®Processor E3000∆
Series
Thermal and Mechanical Design Guidelines
November 2010

2 Thermal and Mechanical Design Guidelines
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Copyright © 2008–2010 Intel Corporation

Thermal and Mechanical Design Guidelines 3
Contents
1Introduction...................................................................................................... 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
2Processor 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
3Thermal 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
4Thermal 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 Thermal and Mechanical Design Guidelines
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
5Balanced 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
5.3Material 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
6ATX 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
7Intel®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

Thermal and Mechanical Design Guidelines 5
7.3 Intel®QST Configuration and Tuning........................................................68
7.4 Fan Hub Thermistor and Intel®QST .........................................................68
Appendix A LGA775 Socket Heatsink Loading........................................................................69
A.1 LGA775 Socket Heatsink Considerations ...................................................69
A.2 Metric for Heatsink Preload for ATX/uATX Designs Non-Compliant with Intel®
Reference Design...................................................................................69
A.3 Heatsink Preload Requirement Limitations.................................................69
A.3.1 Motherboard Deflection Metric Definition......................................70
A.3.2 Board Deflection Limits..............................................................71
A.3.3 Board Deflection Metric Implementation Example .........................72
A.3.4 Additional Considerations...........................................................73
A.3.4.1 Motherboard Stiffening Considerations .........................74
A.4 Heatsink Selection Guidelines..................................................................74
Appendix B Heatsink Clip Load Metrology .............................................................................75
B.1 Overview ..............................................................................................75
B.2 Test Preparation ....................................................................................75
B.2.1 Heatsink Preparation.................................................................75
B.2.2 Typical Test Equipment .............................................................78
B.3 Test Procedure Examples........................................................................78
B.3.1 Time-Zero, Room Temperature Preload Measurement ...................79
B.3.2 Preload Degradation under Bake Conditions.................................79
Appendix C Thermal Interface Management..........................................................................81
C.1 Bond Line Management ..........................................................................81
C.2 Interface Material Area ...........................................................................81
C.3 Interface Material Performance................................................................81
Appendix D Case Temperature Reference Metrology...............................................................83
D.1 Objective and Scope...............................................................................83
D.2 Supporting Test Equipment.....................................................................83
D.3 Thermal Calibration and Controls.............................................................85
D.4 IHS Groove...........................................................................................85
D.5 Thermocouple Attach Procedure...............................................................89
D.5.1 Thermocouple Conditioning and Preparation.................................89
D.5.2Thermocouple Attachment to the IHS..........................................90
D.5.3 Solder Process .........................................................................95
D.5.4 Cleaning and Completion of Thermocouple Installation..................98
D.6 Thermocouple Wire Management...........................................................102
Appendix E Balanced Technology Extended (BTX) System Thermal Considerations ..................103
Appendix F Fan Performance for Reference Design ..............................................................107
Appendix G Mechanical Drawings.......................................................................................109
Appendix H Intel® Enabled Reference Solution Information ...................................................125

6 Thermal and Mechanical Design Guidelines
Figures
Figure 2-1. Package IHS Load Areas ...................................................................13
Figure 2-2. Processor Case Temperature Measurement Location.............................17
Figure 2-3. Example Thermal Profile....................................................................18
Figure 3-1. Processor Thermal Characterization Parameter Relationships.................26
Figure 3-2. Locations for Measuring Local Ambient Temperature, Active ATX Heatsink29
Figure 3-3. Locations for Measuring Local Ambient Temperature, Passive Heatsink ...29
Figure 4-1. Thermal Monitor Control....................................................................33
Figure 4-2. Thermal Monitor 2 Frequency and Voltage Ordering..............................34
Figure 4-3. TCONTROL for Digital Thermal Sensor.....................................................37
Figure 5-1. Effective TMA Fan Curves with Reference Extrusion ..............................42
Figure 5-2. Random Vibration PSD......................................................................44
Figure 5-3. Shock Acceleration Curve..................................................................44
Figure 5-4. Intel®Type II TMA 65W Reference Design...........................................47
Figure 5-5. Upward Board Deflection During Shock ...............................................48
Figure 5-6. Minimum Required Processor Preload to Thermal Module Assembly
Stiffness....................................................................................................49
Figure 5-7. Thermal Module Attach Pointes and Duct-to-SRM Interface Features.......50
Figure 6-1. E18764-001 Reference Design – Exploded View...................................52
Figure 6-2. Bottom View of Copper Core Applied by TC-1996 Grease.......................52
Figure 6-3. Random Vibration PSD......................................................................56
Figure 6-4. Shock Acceleration Curve..................................................................56
Figure 6-5. Upward Board Deflection during Shock................................................60
Figure 6-6. Reference Clip/Heatsink Assembly......................................................61
Figure 6-7. Critical Parameters for Interfacing to Reference Clip.............................62
Figure 6-8. Critical Core Dimension.....................................................................62
Figure 7-1. Intel®QST Overview ........................................................................64
Figure 7-2. PID Controller Fundamentals .............................................................65
Figure 7-3. Intel®QST Platform Requirements .....................................................66
Figure 7-4. Example Acoustic Fan Speed Control Implementation...........................67
Figure 7-5. Digital Thermal Sensor and Thermistor ...............................................68
Figure 7-6. Board Deflection Definition................................................................71
Figure 7-7. Example—Defining Heatsink Preload Meeting Board Deflection Limit.......73
Figure 7-8. Load Cell Installation in Machined Heatsink Base Pocket – Bottom View ..76
Figure 7-9. Load Cell Installation in Machined Heatsink Base Pocket – Side View ......77
Figure 7-10. Preload Test Configuration...............................................................77
Figure 7-11. Omega Thermocouple.....................................................................84
Figure 7-12. 775-LAND LGA Package Reference Groove Drawing at 6 o’clock Exit.....86
Figure 7-13. 775-LAND LGA Package Reference Groove Drawing at 3 o’clock Exit (Old
Drawing)...................................................................................................87
Figure 7-14. IHS Groove at 6 o’clock Exit on the 775-LAND LGA Package ................88
Figure 7-15. IHS Groove at 6 o’clock Exit Orientation Relative to the LGA775 Socket 88
Figure 7-16. Inspection of Insulation on Thermocouple..........................................89
Figure 7-17. Bending the Tip of the Thermocouple................................................90
Figure 7-18. Securing Thermocouple Wires with Kapton* Tape Prior to Attach..........90
Figure 7-19. Thermocouple Bead Placement.........................................................91
Figure 7-20. Position Bead on the Groove Step.....................................................92
Figure 7-21. Detailed Thermocouple Bead Placement ............................................92
Figure 7-22. Third Tape Installation ....................................................................93
Figure 7-23. Measuring Resistance between Thermocouple and IHS........................93
Figure 7-24. Applying Flux to the Thermocouple Bead...........................................94
Figure 7-25. Cutting Solder................................................................................94
Figure 7-26. Positioning Solder on IHS ................................................................95

Thermal and Mechanical Design Guidelines 7
Figure 7-27. Solder Station Setup.......................................................................96
Figure 7-28. View Through Lens at Solder Station.................................................97
Figure 7-29. Moving Solder back onto Thermocouple Bead.....................................97
Figure 7-30. Removing Excess Solder..................................................................98
Figure 7-31. Thermocouple placed into groove .....................................................99
Figure 7-32. Removing Excess Solder..................................................................99
Figure 7-33. Filling Groove with Adhesive ..........................................................100
Figure 7-34. Application of Accelerant ...............................................................100
Figure 7-35. Removing Excess Adhesive from IHS ..............................................101
Figure 7-36. Finished Thermocouple Installation.................................................101
Figure 7-37. Thermocouple Wire Management....................................................102
Figure 7-38. System Airflow Illustration with System Monitor Point Area Identified .104
Figure 7-39. Thermal sensor Location Illustration ...............................................105
Figure 7-40. ATX/µATX Motherboard Keep-out Footprint Definition and Height
Restrictions for Enabling Components - Sheet 1 ...........................................110
Figure 7-41. ATX/µATX Motherboard Keep-out Footprint Definition and Height
Restrictions for Enabling Components - Sheet 2 ...........................................111
Figure 7-42. ATX/µATX Motherboard Keep-out Footprint Definition and Height
Restrictions for Enabling Components - Sheet 3 ...........................................112
Figure 7-43. BTX Thermal Module Keep Out Volumetric – Sheet 1.........................113
Figure 7-44. BTX Thermal Module Keep Out Volumetric – Sheet 2.........................114
Figure 7-45. BTX Thermal Module Keep Out Volumetric – Sheet 3.........................115
Figure 7-46. BTX Thermal Module Keep Out Volumetric – Sheet 4.........................116
Figure 7-47. BTX Thermal Module Keep Out Volumetric – Sheet 5.........................117
Figure 7-48. ATX Reference Clip – Sheet 1.........................................................118
Figure 7-49. ATX Reference Clip - Sheet 2 .........................................................119
Figure 7-50. Reference Fastener - Sheet 1.........................................................120
Figure 7-51. Reference Fastener - Sheet 2.........................................................121
Figure 7-52. Reference Fastener - Sheet 3.........................................................122
Figure 7-53. Reference Fastener - Sheet 4.........................................................123
Figure 7-54. Intel®E18764-001 Reference Solution Assembly..............................124
Tables
Table 2–1. Heatsink Inlet Temperature of Intel®Reference Thermal Solutions..........22
Table 2–2. Heatsink Inlet Temperature of Intel®Boxed Processor Thermal Solutions.22
Table 5–1. Balanced Technology Extended (BTX) Type II Reference TMA Performance39
Table 5–2. Acoustic Targets ...............................................................................40
Table 5–3. VR Airflow Requirements....................................................................42
Table 5–4. Processor Preload Limits....................................................................49
Table 6–1. E18764-001 Reference Heatsink Performance ......................................53
Table 6–2. Acoustic Results for ATX Reference Heatsink (E18764-001)....................54
Table 7–1. Board Deflection Configuration Definitions............................................70
Table 7–2. Typical Test Equipment......................................................................78
Table 7–3. Fan Electrical Performance Requirements...........................................107
Table 7–4. Intel®Representative Contact for Licensing Information of BTX Reference
Design ....................................................................................................125
Table 7–5. E18764-001 Reference Thermal Solution Providers .............................125
Table 7–6. BTX Reference Thermal Solution Providers.........................................126

8 Thermal and Mechanical Design Guidelines
Revision History
Revision
Number Description Revision
001 •Initial release. January 2008
002 •Added Intel®Core™2 Duo processor E8300 and E7200 April 2008
003 •Added Intel®Core™2 Duo processor E8600 and E7300 August 2008
004 •Added Intel®Pentium dual-core processor E5200 August 2008
005 •Added Intel®Core™2 Duo processor E7400 October 2008
006 •Added Intel®Pentium dual-core processor E5300 December 2008
007 •Added Intel®Pentium dual-core processor E5400
•Added Intel®Core™2 Duo processor E7500 January 2009
008 •Added Intel®Pentium dual-core processor E6300 May 2009
009 •Added Intel®Core™2 Duo processor E7600 June 2009
010 •Added Intel®Pentium dual-core processor E6500 August 2009
011 •Intel®Celeron®processor E3x00 series August 2009
012 •Added Intel®Pentium dual-core processor E6600
•Intel®Celeron®processor E3400 January 2010
013 •Added Intel®Pentium dual-core processor E5500 April 2010
014 •Added Intel®Pentium dual-core processor E6700 June 2010
015 •Added Intel®Pentium dual-core processor E5700 August 2010
016
•Added Intel®Pentium dual-core processor E6800
•Added Intel®Celeron®processor E3500
•Changed the processor numbering from Intel Celeron processor E3x00
series to Intel Celeron processor E3000 series.
August 2010
017 •Added Intel®Pentium dual-core processor E5800 November 2010
§

Introduction
Thermal and Mechanical Design Guidelines 9
1Introduction
1.1 Document Goals and Scope
1.1.1 Importance of Thermal Management
The objective of thermal management is to ensure that the temperatures of all
components in a system are maintained within their functional temperature range.
Within this temperature range, a component is expected to meet its specified
performance. Operation outside the functional temperature range can degrade system
performance, cause logic errors or cause component and/or system damage.
Temperatures exceeding the maximum operating limit of a component may result in
irreversible changes in the operating characteristics of this component.
In a system environment, the processor temperature is a function of both system and
component thermal characteristics. The system level thermal constraints consist of the
local ambient air temperature and airflow over the processor as well as the physical
constraints at and above the processor. The processor temperature depends in
particular on the component power dissipation, the processor package thermal
characteristics, and the processor thermal solution.
All of these parameters are affected by the continued push of technology to increase
processor performance levels and packaging density (more transistors). As operating
frequencies increase and packaging size decreases, the power density increases while
the thermal solution space and airflow typically become more constrained or remains
the same within the system. The result is an increased importance on system design
to ensure that thermal design requirements are met for each component, including the
processor, in the system.
1.1.2 Document Goals
Depending on the type of system and the chassis characteristics, new system and
component designs may be required to provide adequate cooling for the processor.
The goal of this document is to provide an understanding of these thermal
characteristics and discuss guidelines for meeting the thermal requirements imposed
on single processor systems using the Intel®Core™2 Duo processor E8000, E7000
series, Intel®Pentium®dual-core processor E6000, E5000 series, and Intel®Celeron®
processor E3000 series.
The concepts given in this document are applicable to any system form factor. Specific
examples used will be the Intel enabled reference solution for ATX/uATX systems. See
the applicable BTX form factor reference documents to design a thermal solution for
that form factor.

Introduction
10 Thermal and Mechanical Design Guidelines
1.1.3 Document Scope
This design guide supports the following processors:
•Intel®Core™2 Duo processor E8000 series with 6 MB cache applies to Intel®
Core™2 Duo processors E8600, E8500, E8400, E8300, E8200, and E8190
•Intel®Core™2 Duo processor E7000 series with 3 MB cache applies to Intel®
Core™2 Duo processors E7600, E7500, E7400, E7300, and E7200
•Intel®Pentium®dual-core processor E5000 series with 2 MB cache applies to
Intel®Pentium®dual-core processors E5800, E5700, E5500, E5400, E5300, and
E5200
•Intel®Pentium®dual-core processor E6000 series with 2 MB cache applies to
Intel®Pentium®dual-core processor E6800, E6700, E6600, E6500, and E6300
•Intel®Celeron®processor E3000 series with 1 MB cache applies to the Intel®
Celeron®processor E3500, E3400, E3300, and E3200
In this document when a reference is made to “the processor” it is intended that this
includes all the processors supported by this document. If needed for clarity, the
specific processor will be listed.
In this document, when a reference is made to the “the reference design” it is
intended that this means ATX reference designs (E18764-001) supported by this
document. If needed for clarify, the specific reference design will be listed.
In this document, when a reference is made to “the datasheet”, the reader should
refer to the Intel®Core™2 Duo Processor E8000 and E7000 Series Datasheet, Intel®
Pentium®Dual-Core Processor E6000 and E5000 Series Datasheet, and Intel®
Celeron®Processor E3000 Series Datasheet. If needed for clarity the specific
processor datasheet will be referenced.
Chapter 2 of this document discusses package thermal mechanical requirements to
design a thermal solution for the processor in the context of personal computer
applications.
Chapter 3 discusses the thermal solution considerations and metrology
recommendations to validate a processor thermal solution.
Chapter 4 addresses the benefits of the processor’s integrated thermal management
logic for thermal design.
Chapter 5 gives information on the Intel reference thermal solution for the processor
in BTX platform.
Chapter 6 gives information on the Intel reference thermal solution for the processor
in ATX platform.
Chapter 7 discusses the implementation of acoustic fan speed control.
The physical dimensions and thermal specifications of the processor that are used in
this document are for illustration only. Refer to the datasheet for the product
dimensions, thermal power dissipation and maximum case temperature. In case of
conflict, the data in the datasheet supersedes any data in this document.

Introduction
Thermal and Mechanical Design Guidelines 11
1.2 References
Material and concepts available in the following documents may be beneficial when
reading this document.
Material and concepts available in the following documents may be beneficial when
reading this document.
Document Location
Intel®Core™2 Duo Processor E8000 and E7000 Series
Datasheet www.intel.com/design/processor/d
atashts/318732.htm
Intel®Pentium®Dual-Core Processor E6000 and E5000
Series Datasheet http://download.intel.com/design/
processor/datashts/320467.pdf
Intel®Celeron®Processor E3000 Series Datasheet http://download.intel.com/design/
processor/datashts/322567.pdf
LGA775 Socket Mechanical Design Guide http://developer.intel.com/design/
Pentium4/guides/302666.htm
uATX SFF Design Guidance http://www.formfactors.org/
Fan Specification for 4-wire PWM Controlled Fans http://www.formfactors.org/
ATX Thermal Design Suggestions http://www.formfactors.org/
microATX Thermal Design Suggestions http://www.formfactors.org/
Balanced Technology Extended (BTX) System Design
Guide http://www.formfactors.org/
Thermally Advantaged Chassis Design Guide http://www.intel.com/go/chassis/
1.3 Definition of Terms
Term Description
TAThe measured ambient temperature locally surrounding the processor. The
ambient temperature should be measured just upstream of a passive heatsink
or at the fan inlet for an active heatsink.
TCThe case temperature of the processor, measured at the geometric center of
the topside of the IHS.
TEThe ambient air temperature external to a system chassis. This temperature
is usually measured at the chassis air inlets.
TSHeatsink temperature measured on the underside of the heatsink base, at a
location corresponding to TC.
TC-MAX The maximum case temperature as specified in a component specification.
ΨCA
Case-to-ambient thermal characterization parameter (psi). A measure of
thermal solution performance using total package power. This is defined as:
(TC– TA) / Total Package Power.
Note: Heat source must be specified for Ψmeasurements.

Introduction
12 Thermal and Mechanical Design Guidelines
Term Description
ΨCS
Case-to-sink thermal characterization parameter. A measure of thermal
interface material performance using total package power. This is defined as:
(TC– TS) / Total Package Power.
Note: Heat source must be specified for Ψmeasurements.
ΨSa
Sink-to-ambient thermal characterization parameter. A measure of heatsink
thermal performance using total package power. This is defined as: (TS– TA) /
Total Package Power.
Note: Heat source must be specified for Ψmeasurements.
TIM Thermal Interface Material: The thermally conductive compound between the
heatsink and the processor case. This material fills the air gaps and voids, and
enhances the transfer of the heat from the processor case to the heatsink.
PMAX The maximum power dissipated by a semiconductor component.
TDP Thermal Design Power: a power dissipation target based on worst-case
applications. Thermal solutions should be designed to dissipate the thermal
design power.
IHS Integrated Heat Spreader: a thermally conductive lid integrated into a
processor package to improve heat transfer to a thermal solution through
heat spreading.
LGA775
Socket The surface mount socket designed to accept the processors in the 775–Land
LGA package.
ACPI Advanced Configuration and Power Interface.
Bypass Bypass is the area between a passive heatsink and any object that can act to
form a duct. For this example, it can be expressed as a dimension away from
the outside dimension of the fins to the nearest surface.
Thermal
Monitor A feature on the processor that attempts to keep the processor die
temperature within factory specifications.
TCC Thermal Control Circuit: Thermal Monitor uses the TCC to reduce die
temperature by lowering the effective processor frequency when the die
temperature has exceeded its operating limits.
DTS Digital Thermal Sensor: Processor die sensor temperature defined as an offset
from the onset of PROCHOT#.
FSC Fan Speed Control: Thermal solution that includes a variable fan speed which
is driven by a PWM signal and uses the on-die thermal diode as a reference to
change the duty cycle of the PWM signal.
TCONTROL TCONTROL is the specification limit for use with the on-die thermal diode.
PWM Pulse width modulation is a method of controlling a variable speed fan. The
enabled 4-wire fans use the PWM duty cycle % from the fan speed controller
to modulate the fan speed.
Health
Monitor
Component
Any standalone or integrated component that is capable of reading the
processor temperature and providing the PWM signal to the 4-pin fan header.
BTX Balanced Technology Extended.
TMA Thermal Module Assembly. The heatsink, fan and duct assembly for the BTX
thermal solution

Processor Thermal/Mechanical Information
Thermal and Mechanical Design Guidelines 13
2Processor Thermal/Mechanical
Information
2.1 Mechanical Requirements
2.1.1 Processor Package
The processors covered in the document are packaged in a 775-Land LGA package
that interfaces with the motherboard using a LGA775 socket. Refer to the datasheet
for detailed mechanical specifications.
The processor connects to the motherboard through a land grid array (LGA) surface
mount socket. The socket contains 775 contacts arrayed about a cavity in the center
of the socket with solder balls for surface mounting to the motherboard. The socket is
named LGA775 socket. A description of the socket can be found in the LGA775 Socket
Mechanical Design Guide.
The package includes an integrated heat spreader (IHS) that is shown in Figure 2-1
for illustration only. Refer to the processor datasheet for further information. In case
of conflict, the package dimensions in the processor datasheet supersedes dimensions
provided in this document.
Figure 2-1. Package IHS Load Areas

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14 Thermal and Mechanical Design Guidelines
The primary function of the IHS is to transfer the non-uniform heat distribution from
the die to the top of the IHS, out of which the heat flux is more uniform and spread
over a larger surface area (not the entire IHS area). This allows more efficient heat
transfer out of the package to an attached cooling device. The top surface of the IHS
is designed to be the interface for contacting a heatsink.
The IHS also features a step that interfaces with the LGA775 socket load plate, as
described in LGA775 Socket Mechanical Design Guide. The load from the load plate is
distributed across two sides of the package onto a step on each side of the IHS. It is
then distributed by the package across all of the contacts. When correctly actuated,
the top surface of the IHS is above the load plate allowing proper installation of a
heatsink on the top surface of the IHS. After actuation of the socket load plate, the
seating plane of the package is flush with the seating plane of the socket. Package
movement during socket actuation is along the Z direction (perpendicular to
substrate) only. Refer to the LGA775 Socket Mechanical Design Guide for further
information about the LGA775 socket.
The processor package has mechanical load limits that are specified in the processor
datasheet. The specified maximum static and dynamic load limits should not be
exceeded during their respective stress conditions. These include heatsink installation,
removal, mechanical stress testing, and standard shipping conditions.
•When a compressive static load is necessary to ensure thermal performance of the
thermal interface material between the heatsink base and the IHS, it should not
exceed the corresponding specification given in the processor datasheet.
•When a compressive static load is necessary to ensure mechanical performance, it
should remain in the minimum/maximum range specified in the processor
datasheet
•The heatsink mass can also generate additional dynamic compressive load to the
package during a mechanical shock event. Amplification factors due to the impact
force during shock must be taken into account in dynamic load calculations. The
total combination of dynamic and static compressive load should not exceed the
processor datasheet compressive dynamic load specification during a vertical
shock. For example, with a 0.550 kg [1.2 lb] heatsink, an acceleration of 50G
during an 11 ms trapezoidal shock with an amplification factor of 2 results in
approximately a 539 N [117 lbf] dynamic load on the processor package. If a
178 N [40 lbf] static load is also applied on the heatsink for thermal performance
of the thermal interface material the processor package could see up to a 717 N
[156 lbf]. The calculation for the thermal solution of interest should be compared
to the processor datasheet specification.
No portion of the substrate should be used as a load- bearing surface.
Finally, the processor datasheet provides package handling guidelines in terms of
maximum recommended shear, tensile and torque loads for the processor IHS relative
to a fixed substrate. These recommendations should be followed in particular for
heatsink removal operations.

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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.
One of the strategies for mechanical protection of the socket is to use a preload
and high stiffness clip. This strategy is implemented by the reference design and
described in Section 6.7.
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 Heatsink Clip Load Requirement
The attach mechanism for the heatsink 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 reference design assumptions:
•72 mm x 72 mm mounting hole span for ATX (refer to Figure 7-40)
•TMA preload versus stiffness for BTX within the limits shown on Figure 5-6
•And no board stiffening device (backing plate, chassis attach, and so forth).
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 clip and fastener to the required minimum load. This means that,
depending on clip stiffness, 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.

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16 Thermal and Mechanical Design Guidelines
2.1.2.3 Additional Guidelines
In addition to the general guidelines given above, the heatsink attach mechanism for
the processor should be designed to the following guidelines:
•Holds the heatsink in place under mechanical shock and vibration events and
applies force to the heatsink base to maintain desired pressure on the thermal
interface material. Note that the load applied by the heatsink attach mechanism
must comply with the package specifications described in the processor datasheet.
One of the key design parameters is the height of the top surface of the processor
IHS above the motherboard. The IHS height from the top of board is expected to
vary from 7.517 mm to 8.167 mm. This data is provided for information only, and
should be derived from:
The height of the socket seating plane above the motherboard after reflow, given
in the LGA775 Socket Mechanical Design Guide with its tolerances.
The height of the package, from the package seating plane to the top of the IHS,
and accounting for its nominal variation and tolerances that are given in the
corresponding processor datasheet.
•Engages easily, and if possible, without the use of special tools. In general, the
heatsink is assumed to be installed after the motherboard has been installed into
the chassis.
•Minimizes contact with the motherboard surface during installation and actuation
to avoid scratching the motherboard.
2.2 Thermal Requirements
Refer to the datasheet for the processor thermal specifications. The majority of
processor power is dissipated through the IHS. There are no additional components
(such as BSRAMs) that generate heat on this package. The amount of power that can
be dissipated as heat through the processor package substrate and into the socket is
usually minimal.
The thermal limits for the processor are the Thermal Profile and TCONTROL. The Thermal
Profile defines the maximum case temperature as a function of power being
dissipated. TCONTROL is a specification used in conjunction with the temperature
reported by the digital thermal sensor and a fan speed control method. Designing to
these specifications allows optimization of thermal designs for processor performance
and acoustic noise reduction.
2.2.1 Processor Case Temperature
For the processor, the case temperature is defined as the temperature measured at
the geometric center of the package on the surface of the IHS. For illustration,
Figure 2-2 shows the measurement location for a 37.5 mm x 37.5 mm [1.474 in x
1.474 in] 775-Land LGA processor package with a 28.7 mm x 28.7 mm [1.13 in x
1.13 in] IHS top surface. Techniques for measuring the case temperature are detailed
in Section 3.4.

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Thermal and Mechanical Design Guidelines 17
Figure 2-2. Processor Case Temperature Measurement Location
37.5 mm
Measure TCat thispoint
(geometric center of the package)
37.5 mm
37.5 mm
Measure TCat thispoint
(geometric center of the package)
37.5 mm
2.2.2 Thermal Profile
The Thermal Profile defines the maximum case temperature as a function of processor
power dissipation. Refer to the datasheet for the further information.
2.2.3 Thermal Solution Design Requirements
While the thermal profile provides flexibility for ATX /BTX thermal design based on its
intended target thermal environment, thermal solutions that are intended to function
in a multitude of systems and environments need to be designed for the worst-case
thermal environment. The majority of ATX /BTX platforms are targeted to function in
an environment that will have up to a 35 °C ambient temperature external to the
system.
For ATX platforms, an active air-cooled design, assumed be used in ATX Chassis, with
a fan installed at the top of the heatsink equivalent to the reference design (see
Chapter 6) should be designed to manage the processor TDP at an inlet temperature
of 35 °C + 5°C = 40 °C.
For BTX platforms, a front-to-back cooling design equivalent to Intel BTX TMA Type II
reference design (see the Chapter 5) should be designed to manage the processor
TDP at an inlet temperature of 35 °C + 0.5 °C = 35.5 °C.
The slope of the thermal profile was established assuming a generational improvement
in thermal solution performance of the Intel reference design. For an example of Intel
Core™2 Duo processor E8000 series with 6 MB in ATX platform, its improvement is
about 15% over the Intel reference design (E18764-001). This performance is
expressed as the slope on the thermal profile and can be thought of as the thermal
resistance of the heatsink attached to the processor, ΨCA (Refer to Section 3.1). The
intercept on the thermal profile assumes a maximum ambient operating condition that
is consistent with the available chassis solutions.

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18 Thermal and Mechanical Design Guidelines
The thermal profiles for the Intel Core™2 Duo processor E8000 series with 6 MB
cache, Intel Core™2 Duo processor E7000 series with 3 MB cache, and Intel Pentium
dual-core processor E6000 and E5000 series with 2 MB cache, and Intel Celeron
processor E3000 series with 1 MB cache are defined such that there is a single
thermal solution for all of the 775_VR_CONFIG_06 processors.
To determine compliance to the thermal profile, a measurement of the actual
processor power dissipation is required. The measured power is plotted on the
Thermal Profile to determine the maximum case temperature. Using the example in
Figure 2-3 for a processor dissipating 50 W the maximum case temperature is 58 °C.
See the datasheet for the thermal profile.
Figure 2-3. Example Thermal Profile
2.2.4 TCONTROL
TCONTROL defines the maximum operating temperature for the digital thermal sensor
when the thermal solution fan speed is being controlled by the digital thermal sensor.
The TCONTROL parameter defines a very specific processor operating region where fan
speed can be reduced. This allows the system integrator a method to reduce the
acoustic noise of the processor cooling solution, while maintaining compliance to the
processor thermal specification.
Note: The TCONTROL value for the processor is relative to the Thermal Control Circuit (TCC)
activation set point which will be seen as 0 using the digital thermal sensor. As a
result the TCONTROL value will always be a negative number. See Chapter 4 for the
discussion the thermal management logic and features and Chapter 7 on Intel Quiet
System Technology (Intel QST).
The value of TCONTROL is driven by a number of factors. One of the most significant of
these is the processor idle power. As a result a processor with a high (closer to 0)
TCONTROL will dissipate more power than a part with lower value (farther from 0, such
as larger negative number) of TCONTROL when running the same application.
40
50
60
70
010 20 30 40 50 60 70
Power (W)
Case Temperature (°C)
Thermal Profile
TDP

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Thermal and Mechanical Design Guidelines 19
This is achieved in part by using the ΨCA versus RPM and RPM versus Acoustics (dBA)
performance curves from the Intel enabled thermal solution. A thermal solution
designed to meet the thermal profile would be expected to provide similar acoustic
performance of different parts with potentially different TCONTROL values.
The value for TCONTROL is calculated by the system BIOS based on values read from a
factory configured processor register. The result can be used to program a fan speed
control component. See the appropriate processor datasheet for further details on
reading the register and calculating TCONTROL.
See Chapter 7, Intel®Quiet System Technology (Intel®QST), for details on
implementing a design using TCONTROL and the Thermal Profile.
2.3 Heatsink 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 stricter. Thermal interface material
(TIM) is used to fill in the gap between the IHS and the bottom surface of the
heatsink, and thereby improve the overall performance of the stack-up (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 applied to it. Refer to Section 2.3.4 and
Appendix C for further information on TIM and on bond line management 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, TA, and the local air velocity over the surface. The higher the air velocity over
the surface, and the cooler the air, the more efficient is the resulting cooling. The
nature of the airflow can also enhance heat transfer using convection. Turbulent
flow can provide improvement over laminar flow. In the case of a heatsink, the
surface exposed to the flow includes in particular the fin faces and the heatsink
base.
Active heatsinks typically incorporate 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 lower air speed. These heatsinks are therefore
typically larger (and heavier) than active heatsinks due to the increase in fin surface

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20 Thermal and Mechanical Design Guidelines
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 travels around the heatsink instead of through it, unless air
bypass is carefully managed. Using air-ducting techniques to manage bypass area can
be an effective method for controlling airflow through the heatsink.
2.3.1 Heatsink Size
The size of the heatsink is dictated by height restrictions for installation in a system
and by the real estate available on the motherboard and other considerations for
component height and placement in the area potentially impacted by the processor
heatsink. The height of the heatsink must comply with the requirements and
recommendations published for the motherboard form factor of interest. Designing a
heatsink to the recommendations may preclude using it in system adhering strictly to
the form factor requirements, while still in compliance with the form factor
documentation.
For the ATX/microATX form factor, it is recommended to use:
•The ATX motherboard keep-out footprint definition and height restrictions for
enabling components, defined for the platforms designed with the LGA775 socket
in Appendix G of this design guide.
•The motherboard primary side height constraints defined in the ATX Specification
V2.1 and the microATX Motherboard Interface Specification V1.1 found at
http://www.formfactors.org/.
The resulting space available above the motherboard is generally not entirely available
for the heatsink. The target height of the heatsink must take into account airflow
considerations (for fan performance for example) as well as other design
considerations (air duct, and so forth).
For BTX form factor, it is recommended to use:
•The BTX motherboard keep-out footprint definitions and height restrictions for
enabling components for platforms designed with the LGA77 socket in Appendix G
of this design guide.
•An overview of other BTX system considerations for thermal solutions can be
obtained in the latest version of the Balanced Technology Extended (BTX) System
Design Guide found at http://www.formfactors.org/.
2.3.2 Heatsink Mass
With the need to push air cooling to better performance, heatsink solutions tend to
grow larger (increase in fin surface) resulting in increased mass. The insertion of
highly thermally conductive materials like copper to increase heatsink thermal
conduction performance results in even heavier solutions. As mentioned in
Section 2.1, the heatsink mass must take into consideration the package and socket
load limits, the heatsink attach mechanical capabilities, and the mechanical shock and
vibration profile targets. Beyond a certain heatsink mass, the cost of developing and
implementing a heatsink attach mechanism that can ensure the system integrity
under the mechanical shock and vibration profile targets may become prohibitive.