Thin Glass Interposers with High-Density Interconnects

• DOI: 10.4071/001c.129006
• Publication Date: 2025-01-30T21:37:29Z
• Authors: Shelby F. Nelson

Glass has excellent electrical and mechanical properties for advanced electronic packaging, and even photonics applications. With a large bulk resistance, low moisture sensitivity, and dimensional stability, glass wafers have properties that allow them to be inserted in many of the processes typically used for silicon, and also allow advantaged performance in some applications, especially those involving high frequency. Thin glass is required to keep latency low and form-factor contained. In this presentation, we will describe the capability to produce void-free, hermetic, copper-filled vias, ranging in aspect ratio from 2:1 to 8:1. We also describe progress in multilayer metallization of thin glass interposers. Five redistribution layers (3 on one side, and 2 on the other) are explored in order to accommodate a relatively high density of interconnects. Daisy-chain structures demonstrate continuity as a function of RDL trace line and space. We report bow measurements on thin glass, exploring the effects of film stress of multiple RDL layers both in a configuration supported by a temporary handle, and free-standing.