You may be familiar with organic substrates, but as of recently, glass core substrates have been gaining traction in the world of semiconductor manufacturing. Glass core substrates are emerging as a possible solution for achieving the interconnect density needed to power applications like artificial intelligence (AI) and high-performance computing (HPC).
Put another way, as the industry becomes pressured to fit more and more computing power in less space than ever to power AI, HPC, and other advanced applications, glass core substrates may be able to help.
But before we get too deep into this topic, I wanted to take a minute to explain what substrates are. The substrate provides the foundation for connecting various electronic components to the package. In the case of glass core substrates, the glass makes the core, upon which other re-distribution layers (RDL) are built.
Organic material is another type of substrate you may be familiar with. In this article, we’ll mainly focus on glass core in comparison to organic substrates. Organic substrates have dominated the industry for a while, but their limitations are prompting the industry to consider glass core instead.
So, to learn more about the world of glass core substrates and what it’ll take for the industry to get on board with implementing them, I spoke with Vik Chaudhry, VP and head of strategic marketing at Yield Engineering Systems (YES). Chaudhry explained the benefits of glass core substrates, sharing that they offer more planarity, higher speeds, and more power handling capabilities over organic substrates – all of which are critical for meeting the demands of advanced technologies.
“The industry is realizing there are limits to the current approach of putting multiple dies together on the organic substrates,” said Chaudhry. “There are limits to the thermal capabilities, and there are limits to the signal integrity with these substrates, so that’s driving the need to find alternate solutions.”
However, despite the promise that glass may offer to the semiconductor industry, there’s still a long way to go to make it viable for widespread use. Chaudhry shared that one of the biggest hurdles with glass core is handling it, because it’s more prone to breakage than organic substrates. In addition, convincing the industry that it’s capable of replacing organic substrates is another roadblock. Even though organic substrates have their own drawbacks, Chaudhry highlighted its long history of use in the semiconductor industry may be hard to overcome initially.
“We need to convince ourselves that [glass] is a viable replacement, especially when it’s going into some of the very high reliability applications like data centers,” he said. “So currently, there’s a lot of work being done to make sure that it’s manufacturable.”
Chaudhry also mentioned that it’s not just the glass core substrates companies need to think about; through glass vias (TGVs), or the vertical connections that pass through the substrate and the interposers, are important too. An interposer typically is a thin piece of silicon material that facilitates communication between different components in a package and substrate.
However, TGVs are important because they enable a higher density of interconnects, which brings the industry closer to achieving the high speed connectivity required by AI and HPC. But to create these TGVs, the glass core substrate itself needs to be thin. This thinness, Chaudhry said, makes the glass even harder to handle. When it comes to glass interposers, Chaudhry highlighted that the technology is still being developed, but YES is helping to lead the way.
“We provide solutions that make very reliable substrates and interposers for this exciting area,” he said. “Some of the work we’ve done in handling different types of glasses with different chemistries, makes us a leader in this space where we can manufacture advanced packaging products with good reliability and quality.”
The moral of the story? Although glass core has a long way to go to become as widespread as organic and silicon substrates, it’s worth keeping our eyes on as the industry demands more from its packaging technology.
Learn more about YES and its leadership in glass core substrates, interposers, and TGVs.
