Intel Pentium 4 Processor In the 423-pin Package Thermal Design Guidelines

Pentium® 4 processor in the 423-pin package Thermal Design Guidelines
7
•
T
AMBIENT-EXTERNAL
- the measured ambient temperature at the OEM defined
external
system location.
•
T
AMBIENT-MAX
- the target worst-case local ambient temperature. This can be determined by placing the system in
maximum external temperature conditions and measuring the ambient temperature locally surrounding the
processor. Under these conditions, T
LA
= T
AMBIENT-MAX
.
•
T
CASE-MAX
- the maximum allowed case temperature of the Pentium 4 processor, as specified in the processor
datasheet.
•
T
CASE
- the measured case temperature of the Pentium® 4 processor.
•
TIM - Thermal Interface Material – The thermally conductive compound between the heat sink and the
processor case. This material fills the air gaps and voids, and enhances the spreading of the heat from the case to
the heat sink.
• θ
TIM
- The thermal resistance of the thermal interface material. Also referred to as “theta case to sink”.
• θ
SA
- The thermal resistance between the heat sink base and the ambient air. This is defined and controlled by
the system thermal solution. Also referred to as “ theta sink to ambient”.
• θ
CA
- The thermal resistance between the processor’s case and the ambient air. This is defined and controlled
by the system thermal solution. Also referred to as “theta case to ambient”, it includes both
θ
CS
and
θ
SA
.
•
P
MAX
- the maximum processor power, as specified in the processor’s datasheet.
•
423 Pin Socket - The through-hole mount Zero Insertion Force (ZIF) socket designed to accept the Pentium 4
processor.
•
ACPI - Advanced Configuration and Power Interface (See http://www.teleport.com/~acpi/)
•
Bypass - Bypass is the area between a heat sink 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 - The Pentium 4 processor implements new thermal management features consisting of: an
on-die thermal diode, external bus signal, thermal control circuit and processor registers to assist with
managing thermal control of the processor.
•
Thermal Control Circuit - The portion of Thermal Monitor, which modulates the clocks during an over-
temperature event.
•
Thermal Design Point (TDP) – Processor thermal solutions should be designed to meet the TDP as listed in the
Pentium 4 processor in the 423 pin Package Datasheet.
1.5 Revision History
Date of Release Revision No. Description
May 1999 0.5 Initial release of document
November 1999 0.6 Updated mechanical drawings. Updated thermal management discussion
January 2000 1.0 Updated mechanical drawings. Updated thermal metrology section
May 2000 1.1 Updated mechanical drawings. Added thermal test software discussion
November 2000 2.0 Final release.