Abstract: Additional “auxiliary” bumps are used to stabilize alignment and reduce slippage of dense arrays of interconnect bumps on opposing die during a bonding process. One example of auxiliary bumps are interdigitated bumps. Interdigitated bumps are more self-aligning and laterally stable because bumps do not meet head-to-head. Rather, the head of a bump on one die falls into the space between bumps on the other die. Another example of auxiliary bumps are nail bumps. In nail bumps, one bump is harder (the nail) and “drives” into the opposing softer bump during bonding. This constrains the lateral movement of the two bumps relative to each other and reduces lateral slippage. In some embodiments, the auxiliary bumps and interconnect bumps are formed in the same process, and also bonded in the same process.

Abstract: Semiconductor package interposers having high-density and high-aspect ratio encapsulated interconnects, and semiconductor package assemblies incorporating such interposers, are described. In an example, a semiconductor package interposer includes several conductive interconnects encapsulated in a polymer substrate and having height dimensions greater than a cross-sectional dimension. The semiconductor package interposer may support a first semiconductor package above a second semiconductor package and may electrically connect die pins of the first semiconductor package to die pins of the second semiconductor package.