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 7
1 Introduction
In this document, when a reference is made to the processor and/or the Intel
®
Pentium
®
4
processor in the 478-pin package, it is intended that this includes the Intel
®
Pentium
®
4 processor
in the 478-pin package and the Intel
®
Pentium
®
4 processor with 512 KB L2 cache on .13 micron
process, unless it is otherwise specified. When a reference is intended to refer to a specific
processor, the specific processors will be listed separately.
This design guide supports the following processors:
• Intel
®
Pentium
®
4 processor in the 478-pin package
• Intel
®
Pentium
®
4 processor with 512KB L2 cache on .13 micron process
The objective of thermal management is to ensure that the temperatures of all components in a
system are maintained within functional temperature range. Within this temperature range, a
component, and in particular its electrical circuits, 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 on the component power dissipation, size and
material (effective thermal conductivity) of the integrated heat spreader, and the presence of a
thermal cooling solution.
All of these parameters are aggravated by the continued push of technology to increase processor
performance levels (higher operating speeds, GHz) and packaging density (more transistors). As
operating frequencies increase and packaging size decreases, the power density increases while the
thermal cooling solution space and airflow typically become more constrained or remain 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.
The thermal power of the Intel Pentium 4 processor in the 478-pin package and the Intel Pentium 4
processor with 512KB L2 cache on .13 micron process generations is higher, as well as more
dense, than previous Intel architecture processors. Depending on the type of system and the chassis
characteristics, new system 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.
Chapter 2 of this document discusses thermal solution design guidelines for the Intel Pentium 4
processor in the 478-pin package, in the context of personal computer application. This chapter
also includes thermal metrology recommendations to validate a processor cooling solution. It
addresses also the benefits of the processor integrated thermal management logic on thermal
design. Chapter 3 details the critical to function dimensions of the Intel reference cooling solution
for the processor.