Thin Glass Handling Solutions for Microelectronics Packaging
Citation
Shorey, Aric, Shelby Nelson, David Levy, and Paul Ballentine. "Thin Glass Handling Solutions for Microelectronics Packaging." International Symposium on Microelectronics, 2020, pp. 1-7.
Keywords
- Glass Substrates
- Through-Glass Vias (TGV)
- Temporary Bonding Technology
- Wafer-Level Packaging
- RF Applications
- High-Volume Manufacturing
- Heterogeneous Integration
- Via Fill
- Chemical Mechanical Polishing (CMP)
- Reliability
- Electronically Steerable Antenna (ESA)
Brief
This article describes a new temporary bonding technology that enables high-volume manufacturing of thin glass solutions for applications such as RF and heterogeneous packaging.
Summary
This article from the 2020 International Symposium on Microelectronics, authored by Shorey et al., focuses on a novel solution for handling thin glass substrates in microelectronics packaging. Here are the key takeaways:
- Thin glass is advantageous: The authors emphasize the benefits of thin glass substrates (<100 µm thick) for various applications, particularly in radio frequency (RF) systems and heterogeneous packaging. These advantages include low RF loss, adjustable thermal expansion properties, excellent surface flatness, and compatibility with panel fabrication for cost-effectiveness.
- Handling is the challenge: The primary hurdle to widespread adoption of thin glass has been the difficulty in handling these fragile substrates using conventional semiconductor processing equipment.
- Temporary bonding solution: The article presents a method using a thin inorganic adhesive to temporarily bond the thin glass wafer to a stronger handle wafer (typically silicon). This approach allows the glass to be processed with existing semiconductor fabrication equipment without modification.
- Process compatibility: The temporary bond remains stable at high temperatures (over 400°C) and is compatible with crucial back-end processes like via fill, chemical mechanical polishing (CMP), redistribution layer (RDL) fabrication, and dicing. The bond can be easily removed mechanically after processing.
- Examples and benefits: The authors demonstrate the effectiveness of their solution through examples such as the fabrication of a multi-layer, glass-based electronically steerable antenna and the successful plating and patterning of nickel/gold structures on thin glass. They highlight the solution's suitability for high-volume manufacturing, enabling hermetic solutions and complex 2.5D and 3D integrations.
The article concludes by reinforcing that this temporary bonding technology effectively addresses the manufacturing challenges associated with thin glass substrates, paving the way for broader adoption in next-generation electronics.