Leveraging Glass Properties for Advanced Packaging
Citation
A. B. Shorey, Y. J. Lu, and G. A. Smith, "Leveraging Glass Properties for Advanced Packaging," 2015 IEEE 65th Electronic Components and Technology Conference (ECTC), 2015, pp. 370–375.
Keywords
- Glass
- Through Glass Via (TGV)
- Interposer
- Packaging
- Coefficient of Thermal Expansion (CTE)
- RF Applications
- Cost-Effective
- Panel Fabrication
- Reliability
- Form Factor
- Metallization
- Fusion Forming
- Willow™ Glass
Brief
This article outlines the advantages of glass as a material for advanced semiconductor packaging, especially its low electrical loss, customizable CTE, and cost-effectiveness in large-scale production. The article focuses on glass's material properties, specifically its low electrical loss at high frequencies, and the ability to adjust its coefficient of thermal expansion (CTE). These properties make glass suitable for various applications, including RF communications and 3D-IC stacking. The article also discusses the cost-effectiveness of glass, attributed to its forming processes that allow for large format and ultra-thin substrates. It concludes by highlighting the successful demonstration of forming through and blind vias in glass, along with reliable copper filling, suggesting glass as a promising material for future packaging.
Summary
The article "Leveraging Glass Properties for Advanced Packaging," published in 2015 by A.B. Shorey, Y.J. Lu, and G.A. Smith from Corning, Incorporated, explores the advantages of using glass in advanced semiconductor packaging.
The authors highlight glass's superior material properties, including:
- Low electrical loss at high frequencies, making it ideal for RF applications.
- High stiffness and adjustable coefficient of thermal expansion (CTE), enabling better warp management in 3D-IC stacks and carrier applications.
- Cost-effectiveness due to its suitability for large-format manufacturing in thin and flexible forms.
The article provides examples of how these properties translate to improved performance:
- Glass interposers with optimized CTE can minimize warp in 3D-IC stacks, leading to increased reliability.
- Glass carriers with CTE matched to silicon are beneficial for thinning silicon interposers and offer advantages like visual bond inspection and laser de-bonding.
- Glass substrates outperform silicon substrates in high-frequency RF applications due to lower signal loss.
Furthermore, the article discusses advancements in glass manufacturing and processing:
- Corning's fusion forming process allows for the production of large, thin, and flexible glass substrates, reducing manufacturing costs.
- Panel processing of glass substrates exceeding 500 mm in size has been achieved, leading to improved flatness and enabling finer lines and spacing for redistribution layers.
- Handling solutions like Corning's Advanced Lift-off Technology (ALoT) address the challenges of processing ultra-thin glass.
- The article presents findings demonstrating the feasibility of metalizing through-glass vias (TGVs) in 100 µm thick glass using ALoT.
The authors conclude that glass is a promising material for next-generation packaging applications due to its:
- Superior electrical performance
- Adjustable CTE
- Cost-effectiveness
- Suitability for high-volume manufacturing