Intel Pentium 4 Processor in the 478-Pin Package Thermal Design Guidelines

Intel
®
Pentium
®
4 Processor in the 478-Pin Package Thermal Design Guidelines
R
Design Guide 9
1.1 References
Material and concepts available in the following documents may be beneficial when reading this
document.
Document Order Number
Intel
®
Pentium
®
4 Processor in the 478-pin Package Datasheet 249887
Intel
®
Pentium
®
4 Processor with 512KB L2 Cache on.13 Micron
Process Datasheet
298643
Intel
®
Pentium
®
4 Processor in the 478-pin Package and Intel
®
850
Chipset Platform Design Guide
249888
Intel
®
Pentium
®
4 Processor in the 478-pin Package and Intel
®
845
Chipset Platform Design Guide
298354
Intel
®
Pentium
®
4 Processor 478-Pin Socket (mPGA478B) Design
Guidelines
249890
Mechanical Enabling for the Intel
®
Pentium
®
4 Processor in the 478-Pin
Package
290728
IA-32 Intel Architecture Software Developer’s Manual: Volume III
System Programming Guide
245472
To obtain these documents visit the Intel web site at http://developer.intel.com/.
1.2 Definition of Terms
Term Description
T
A
The 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 (see Figure 3).
T
E
The measured ambient temperature outside of the system.
T
C
The measured case temperature of the Intel Pentium 4 processor in the 478-pin
package, as defined in Figure 1 and as specified in the processor datasheet.
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 spreading of the heat from the processor case to the heatsink.
θ
CA
The thermal resistance between the processor case and the ambient air. This is
defined and controlled by the system thermal solution. θ
CA
includes both θ
CS
and θ
SA
.
θ
CS
The case to sink thermal resistance, mainly due to the thermal interface material.
θ
SA
The thermal resistance between the heatsink base and the ambient air. This is
defined and controlled by the system thermal solution.
478-Pin Socket The surface mount Zero Insertion Force (ZIF) socket designed to accept the Intel
Pentium 4 processor in the 478-pin 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.