Intel Pentium 4 Processor with 512-KB L2 Cache on 0.13 Micron Process Thermal Design Guidelines

Intel Thermal Mechanical Reference Design Information

48 Intel

Pentium

4 Processor Thermal Design Guide

4.2 Geometrical Envelope for Intel Reference Thermal

Mechanical Design

Figure 21, Figure 22, and Figure 23 show the overall keep-out and keep-in dimensions for the

reference thermal/mechanical enabling design. These dimensions are identical to the ones used for

the Intel Reference Solution for the Pentium 4 processor in the 478-pin package.

Figure 21 and Figure 22 show the motherboard keep-outs and height restrictions under the

enabling component region. Figure 23 shows the overall volumetric keep-in for the enabling

component assembly. This volumetric space encapsulates the processor, the socket, and the entire

thermal/mechanical enabling solution (for example, for the reference design this includes: fan

heatsink assembly, retention mechanism, and attach clips).

Note: Pin A1 and Ball A1, as referred to in Figure 21, do not physically exist on the 478-pin package

and the 478-pin socket respectively. However, they may be used as a reference for design

purposes. Motherboard designers should focus exclusively on Ball A1 callouts to determine

position of the hole respective to the socket when working of the board layout. By design, the

processor is then centered within the hole pattern when the socket is in the closed position. Pin A1

is associated specifically with the package, and its position on the drawing Figure 21 corresponds

to the package within the socket in close position.