Pillar connections for semiconductor chips and method of manufacture

摘要

A flip chip interconnect system comprises an elongated pillar comprising two elongated portions, a first portion including solder with or without lead and a second portion including copper or gold or other material having a higher reflow temperature than the first portion. The second portion is to be connected to the semiconductor chip and has a length preferably of more than 55 microns to reduce the effect of alpha particles from the solder from affecting electronic devices on the chip. The total length of the pillar is preferably in the range of 80 to 120 microns.