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 13
2.2 Thermal Specifications
2.2.1 Processor Case Temperature and Power Dissipation
Refer to the processor datasheet for processor thermal information.
Thermal information for the processor is given in terms of maximum case temperature
specification and thermal design power. These values may depend on the processor frequencies
and also include manufacturing variations. Designing to these values allows optimizing thermal
design for processor performance (refer to section 2.4).
Processor power is dissipated through the IHS. There is no additional component, i.e., BSRAMs,
which generates heat on this package.
The case temperature is defined as the temperature measured at the center of the top surface of the
IHS. For illustration, the measurement location for a 35 mm x 35 mm FC-PGA2 package is shown
in Figure 1. Techniques for measuring the case temperature are detailed in Section 2.3.3.
Figure 1. Processor IHS Temperature Measurement Location
Measure from edge of processor
Measure T
at this point.
C
Thermal interface material
should cover the entire surface
of the Integrated Heat Spreader
0.689”
17.5 mm
0.689”
17.5 mm
35 mm x 35 mm Package
2.2.2 Designing a Cooling Solution for the Intel
®
Pentium
®
4
Processor in the 478-Pin Package
2.2.2.1 Heatsink Solutions
2.2.2.1.1 Heatsink Design Considerations
Considering the power dissipation levels and typical local ambient temperature near the processor
around 45°C in a majority of chassis, the processor temperature cannot be maintained at or below
the specified guidelines without additional thermal enhancement to dissipate the heat generated by
the processor. For the Intel Pentium 4 processor in the 478-pin package, a typical aluminum