interposer

thumb|BGA with an interposer between the Die (integrated circuit)|integrated circuit die to [[ball grid array]] thumb|Pentium II: example of an interposer in dark yellow, Die (integrated circuit)|integrated circuit die to [[ball grid array chip carrier]]

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