Intel Pentium 4 Processor in the 423-pin Package Thermal Solution Functional Specification

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Intel® Pentium® 4 Processor Thermal Solution Functional Specification
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4.2. Maximum Heat Sink Mass
Heat sink mass (including fan, fan attach, and thermal interface) may not exceed 450g.
4.3. Center of Gravity
The center of gravity of the Pentium 4 processor thermal solution should be over the center of
gravity of the package. The height of the center of gravity must be 0.5in, maximum, from the
bottom of the heat sink base.
4.4. Base Plate Requirements
The flatness of the base shall be maintained at 0.002in/in in the localized area (Zone B) as
shown in Figure 3. The base plate contains no keying features and thus can be rotated 180
degrees. A heat sink supported by the Intel reference design Retention Mechanism (RM) must
incorporate two clip attach areas with a minimum width of 0.200in (Zone A), as shown in
Figure 3. The heat sink clip requirements are presented in Section 4.8.
4.5. Recommended Fan Requirements for the Pentium® 4 Processor Solution
The fan design is an integral part of an active thermal solution and will vary widely depending
on the design of the heat sink. Therefore, only general requirements relating to the fan are
prescribed.
Life requirement 40,000 hours (minimum) MTBF at 45°C.
The Pentium 4 processor thermal solution should be capable of meeting the thermal target
specs presented in the Pentium® 4 processor in 423-pin Datasheet at 90% of the rated fan
RPM at 12 Vdc.
The fan acoustic target is 32dB (measured at 1 meter at nominal RPM).
Fan cable connectors shall be 3-pin (power, ground, and signal -- open collector tachometer
output signal requirement: 2 pulses per revolution) connectors capable of terminating to a
vertical-mount printed circuit board (PCB) header (such as 640456-3 (AMP*), or equivalent).
4.6. Fan Attach Requirements
The fan attach must incorporate features to attach the fan directly to the heat sink base. It
should not utilize the fins as an attachment anchor. Additionally, the fan attach should
incorporate a shroud with side features to help prevent side-to-side motion of the fan attach.
4.7. Thermal Interface Material
Intel has determined through thermal characterization that it may be challenging to meet the
thermal performance targets with the use of phase change thermal interface materials. The use
of thermal grease in conjunction with high performance heat sink technologies (e.g. copper