Flip chip interface including a mixed array of heat bumps and signal bumps

摘要

A flip chip interface is described between a semiconductor chip and a substrate having interconnection circuits. Flip chip bumps are provided at the active face of the chip; each bump is preferably a flexible copper pillar fabricated on a pad, and terminating at the substrate in a well filled with conductive material. The conductive material may be a conductive powder during testing and rework, converting to a melted solder in the final assembly. A mixed array of pillars is provided: signal pillars for signals and power, and more closely spaced heat pillars for conducting heat away from the chip. The signal pillars may be provided in row and column arrays on a background of heat pillars, and the layout of pillars may be adjusted to match local heat patterns in the chip.