Patent ID: 9165850
Filing Date: 2015-10-20
Classification: H01L

Abstract:
1. A method of making a flip chip package, comprising: forming a plurality of first polyimide (PI) pads, each having a first pad height on an edge region of a passivation layer of an integrated circuit (IC) chip; forming a plurality of second PI pads, each having a second pad height, a second PI pad from a first portion of said plurality of second PI pads being stacked on each first PI pad of the plurality of first PI pads in said edge region to form a stacked pad, and a second PI pad from a second portion of said plurality of second PI pads being formed on a mid-radial region of said passivation layer; forming a redistribution layer (RDL) that includes a plurality of conductive traces, each conductive trace extending from a lower surface contact proximate to an inner wiring level through an opening in said passivation layer to an upper surface contact disposed on one of: a top surface of each stacked pad in said edge region, a top surface of each second PI pad of the plurality of second PI pads in said mid-radial region, a top surface area of said passivation layer in a central region, a height of each upper surface contact above said passivation layer increasing radially from said central region to said mid-radial region and further increasing radially from said mid-radial region to said edge region; forming a plurality of electrical connectors, each electrical connector being of a same height and being disposed over each upper surface contact of each conductive trace; flipping said IC chip, to which said RDL and said electrical connectors are connected, to form a flipped IC chip; and heating solder joins, disposed on said electrical connectors, to join flip chip attaches, disposed on an opposing chip carrier, to said flipped IC chip and form said flip chip package.