Interposer

BGA with an interposer between the integrated circuit die to ball grid array
Pentium II: example of an interposer, integrated circuit die to ball grid array chip carrier

An interposer is an electrical interface routing between one socket or connection to another. The purpose of an interposer is to spread a connection to a wider pitch or to reroute a connection to a different connection.[1]

Interposer comes from the Latin, interpōnere, meaning 'to put up between.' [2]

A common example of an interposer is an integrated circuit die to BGA, such as in the Pentium II. This is done through various substrates, both rigid and flexible, most commonly FR4 for rigid, and polyimide for flexible.[1]

Another example of an interposer would be the adapter used to allow a SATA drive to work in a SAS environment. An interposer would allow a SATA drive to plug into a SAS backplane, providing pseudo path redundancy.[3]
In recent years, silicon interposer technologies have been adopted for for FPGA and memory applications, and are in development for memory and logic integration. Interposer implementations consist of different technologies (e.g. front-to-back contacts (TSVs), interconnects, pads) for which independent solutions were developed. Interposer interconnects can be manufactured with different schemes, e.g. with planarized or non-planarized materials. The resulting surface topology limits the maximum number of interconnect layers.[4]

See also

References

  1. 1.0 1.1 Package Substrates/Interposers
  2. interposes - definition of interposes by the Free Online Dictionary, Thesaurus and Encyclopedia
  3. Willis Whittington (2007). "Desktop, Nearline & Enterprise Disk Drives" (PDF). Storage Networking Industry Association (SNIA). p. 17. Retrieved 2014-09-22.
  4. Heinig, Andy. "Technology Options and Their Influence on Routing for Interposer-based Memory Processor Integration". 3D InCites Knowledge Portal. 3D InCites. Retrieved April 14, 2014.