Flip chip interconnect method and design for GaAs MMIC applications

摘要

A monolithic microwave integrated circuit (MMIC) flip chip interconnect is formed by coating an active side of the chip with a dielectric coating, such as benzocyclobutene (BCB), that inhibits deposition of metal plating materials. A portion of the dielectric coating is removed to expose bond pads on the active side of the chip, stud bumps are bonded to the bond pads, and the active side is then plated with first and second consecutive metal plating materials, such as nickel and gold, respectively, that do not adhere to the dielectric coating. The chip is then oriented such that the plated stud bumps on the active side of the chip face bond pads on a substrate, and the stud bumps on the chip are bonded to the bond pads on the substrate.