Intel Pentium 4 Processor 478-Pin Socket (mPGA478) Design Guidelines

Intel® Pentium® 4 Processor 478-Pin Socket (mPGA478)
R
8
3. Mechanical Requirements
3.1. Mechanical Supports:
The socket must carry a load of 45.36Kg, compressive, during the shock and vibration conditions outlined in
Section 5. The socket must pass the mechanical shock and vibration and the other use condition requirements
listed in Section 5 with the associated heatsink and applicable retention mechanism or simulation thereof in
place and with out board support. The socket can only be attached by the socket contacts to the motherboard.
No external methods (i.e. screw, extra solder, adhesive....) to attach the socket are acceptable
3.2. Materials
3.2.1. Socket Housing
Thermoplastic or equivalent, UL 94V-0 flame rating, temperature rating and design capable of withstanding
reflow solder process. The material must have a thermal coefficient of expansion in the XY plane capable of
passing reliability tests rated for an expected high operating temperature, mounted on FR4-type motherboard
material.
3.2.2. Color
The color of the socket can be optimized to provide the contrast needed for OEM’s pick and place vision
systems. The base and cover of the socket may be different colors as long as they meet the above
requirement.
3.2.3. Cutouts For Package Removal
Recessed cutouts are required in the side of the socket to provide better access to the package substrate, and
facilitate the manual removal of inserted package. (See attached socket drawing Section 8 – Appendix Z.2).
3.2.4. Socket Standoff Height
Socket stand off height, cover lead in and cover lead in depth must not interfere with package pin shoulder
height at worst case conditions. (See Figure 7-4– Appendix Z.1 for the package solder fillet dimensions.)