Mechanical Enabling for the Intel Pentium 4 Processor in the 478-Pin Package

16
Design Effectiveness
Solder Joint Considerations - 1
 Solder ball damage
 Caused by MB flexure under mechanical shock loads
 Heatsink inertial load reacted through MB bending
CPU heatsinkCPU heatsink
Severe board flexure
under socket and MCH
Heatsink inertial load
reacted through MB
bending
Solder joint
subjected to
tensile and
shear strains
Board curvature
sets up critical
solder ball strains