Processor Thermal/Mechanical Information
R
Thermal/Mechanical Design Guide
23
2.3.4
Thermal Interface Material
Thermal interface material application between the processor IHS and the heatsink base is
generally required to improve thermal conduction from the IHS to the heatsink. Many thermal
interface materials can be pre-applied to the heatsink base prior to shipment from the heatsink
supplier and allow direct heatsink attach, without the need for a separate thermal interface
material dispense or attach process in the final assembly factory.
All thermal interface materials should be sized and positioned on the heatsink base in a way that
ensures the entire processor IHS area is covered. It is important to compensate for heatsink-to-
processor attach positional alignment when selecting the proper thermal interface material size.
When pre-applied material is used, it is recommended to have a protective application tape over
it. This tape must be removed prior to heatsink installation.
2.4
System Thermal Solution Considerations
2.4.1
Chassis Thermal Design Capabilities
The ATX Intel reference thermal solution assumes that the chassis delivers a maximum T
A
of
38 °C at the inlet of the processor fan heatsink (refer to Section 5.1.1).
2.4.2
Improving Chassis Thermal Performance
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 and vents 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,
acoustic requirements and structural considerations that limit the thermal solution size. For more
information, refer to the
Performance ATX Desktop System Thermal Design Suggestions
or
Performance microATX Desktop System Thermal Design Suggestions
documents available on the
http://www.formfactors.org/
web site.
In addition to passive heatsinks, fan heatsinks and system fans are other solutions that 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.
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.
Summary of Contents for 640 - Pentium 4 640 3.2GHz 800MHz 2MB Socket 775 CPU
Page 14: ...Introduction R 14 Thermal Mechanical Design Guide ...
Page 38: ...Thermal Management Logic and Thermal Monitor Feature R 38 Thermal Mechanical Design Guide ...
Page 52: ...Intel Thermal Mechanical Reference Design Information R 52 Thermal Mechanical Design Guide ...
Page 60: ...Acoustic Fan Speed Control R 60 Thermal Mechanical Design Guide ...
Page 72: ...Heatsink Clip Load Metrology R 72 Thermal Mechanical Design Guide ...
Page 99: ...Mechanical Drawings R Thermal Mechanical Design Guide 99 Figure 50 Reference Fastener Sheet 1 ...
Page 103: ...Mechanical Drawings R Thermal Mechanical Design Guide 103 Figure 54 Clip Heatsink Assembly ...
