BGA sockets-a dendritic solution

Today's high density technology requires a large number of I/O pins in CPU packages. The direct soldering of these devices can lead to solder joint reliability concerns. The sockets can provide a cost-effective solution in such applications when it comes to equipment upgrades and reducing the rework cost of CPU replacements. The sockets allow the mother boards to be assembled off shore and imported with low tariffs. The CPUs can then be inserted on the planar according to the demands of US market. This paper compares the current BGA socket technology and describes a low profile BGA/LGA socket based on dendrite technology developed by IBM Microelectronics Division.