A simple PCB placed in between a BGA device and a motherboard to prevent combining
two different solder alloys.
Applications
Long-life cycle and High-Rel markets:
Telcom
Server
Network
Industrial
Avionics
Military
Although many ISI customers are exempt from lead-free and RoHS regulations, some semiconductor suppliers are transitioning their packages to lead free and standard eutectic 63/37 BGAs will no longer be available.
In many cases, PCB assemblies have multiple BGAs from multiple suppliers that are phasing in lead-free packages at different times.
In some cases OEMs maintain several years of inventory of leaded BGA ASICs that were purchased as last-time buys.
Advantages
ISI Interposers offer a practical solution to manufacturing PCB assemblies with both lead-free and leaded BGAs
Alliviates compatibility/reliability issues
A low cost transitionary solution to use-up existing inventories of ASICs
Option 1: ISI supplies interposer with lead-free BGA soldered to top side of interposer
using lead-free solder paste, and leaded 63/37 balls on bottom side. Customer attaches interposer to motherboard with 63/37 solder paste.
Option 2: ISI supplies interposer with 63/37 BGA soldered to top side of interposer
using 63/37 solder paste, and lead-free balls on bottom side. Customer attaches interposer to motherboard with lead-free solder paste.
