Universal solder joints for 3D packaging

摘要

Electronic devices including solder bumps embedded in a pre-applied coating of underfill material and/or solder resist are fabricated, thereby improving chip-package interaction reliability. Underfill can be directly applied to a wafer, enabling increased filler loadings. Passages formed in the underfill and/or solder resist coating expose electrically conductive pads or metal pillars. Such passages can be filled with molten solder to form the solder bumps.

主权项

1. A method comprising:
obtaining a structure including a wafer and a plurality of metal contact structures including metal pillars mounted to the wafer, each of the metal pillars having a top surface; depositing a coating comprising underfill material containing filler material on the wafer, thereby encapsulating the metal pillars; curing the coating on the wafer; forming a plurality of passages through the coating such that a plurality of portions of the top surface of each metal pillar are exposed, respectively, by a plurality of the passages, and filling each of the passages with molten solder, the molten solder forming solder structures contacting the exposed portions of the top surfaces of each metal pillar.