High Precision and Productivity Bridge-die-last Bonding Process and Its Reliability for Pillar- Suspended Bridge (PSB) Architecture

We proposed the Pillar-Suspension Bridge (PSB), a minimum-element chiplet integration architecture, as the most straightforward realization of the MetaIC concept. In this paper, we examine a productive mass reflow process for connecting chiplets and bridges via 40 μm pitch MicroPillar and find that CTE (coefficient of thermal expansion) of the glass carrier is an important factor in achieving fine pitch die-to-die connections in this structure. In addition, reliability tests were conducted on prototype PSB modules fabricated using this bonding process, and excellent reliability was confirmed as an initial result.