Low-Loss, High-Linearity RF Interposers Enabled by Through Glass Vias
Citation
Shah, U., Liljeholm, J., Campion, J., Ebefors, T., & Oberhammer, J. (2018). Low Loss High Linearity RF Interposers Enabled by Through-Glass Vias. IEEE Microwave and Wireless Components Letters, 28(11), 960–962. https://doi.org/10.1109/LMWC.2018.2869285
Keywords
- Through Glass Via (TGV)
- Micromachining
- Heterogeneous Integration
- ow Loss
- High Linearity
Brief
This letter reports a new, low-cost process for fabricating through-glass vias (TGVs) for three-dimensional wafer-level packaging, which achieves low insertion loss and excellent linearity performance.
Summary
This article presents a new type of interposer for use in 3D integrated circuits that utilizes through-glass vias (TGVs) instead of the more common through-silicon vias (TSVs), enabled by a new fabrication process. TGVs offer superior performance in RF applications due to the electrical properties of glass. The new process creates TGVs with an inverted via configuration and a tapered sidewall profile to enable void-free conformal metal coverage, which reduces cost and processing time compared to fully filled TGVs. Simulations showed that conformally plated and fully filled TGVs of the same diameter have similar insertion loss, and the relationship between insertion loss and via diameter and height were examined.
Measurements of a fabricated TGV showed an insertion loss of 0.014 dB at 10 GHz with a DC resistance of 28 mΩ. This performance matches or exceeds other reported TGV technologies and outperforms all reported TSV technologies. Additionally, the linearity of the TGV was assessed by measuring the second and third harmonic levels of a signal passing through the via. The second harmonic level was unchanged compared to a through line without a TGV, while the third harmonic level was 2 dB higher, which the sources consider to be excellent performance.
Origin: https://kth.diva-portal.org/smash/get/diva2:1261803/FULLTEXT01