SK hynix reportedly making High Bandwidth Storage (HBS): stacked chips for next-gen smartphones

SK hynix is reportedly developing High Bandwidth Storage (HBS), which infuses mobile DRAM and NAND into a single package, with the next-gen memory made for boosting AI performance in mobile devices like smartphones and tablets.

In a new report from ETnews picked up by Korean analyst @Jukanlosreve, SK hynix is working on HBS by stacking low-power wide I/O (LPWIO) DRAM together with NAND. There's up to 16 layers of DRAM and NAND that can be stacked and interconnected through "Vertical Wire Fan-Out (VFO)" technology, improving data processing speed.

SK hynix has previously commercialized LPWIO DRAM, and is now looking to use HBS by adding NAND to create a multi-memory stacked structure. The way that SK hynix will achieve this feat with HBS is the VFO advanced packaging, which SK hynix created in a world-first in 2023, vertically connecting each individual memory cell.

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This is different to conventional curved wire bonding, as VFO connects the wires in a straight line, which reduces required wiring length, and minimizes signal transmission loss and delay. Not only that, but the vertical interconnect structure allows greater I/O connections compared to traditional planar connections, increasing data processing performance.

An SK hynix official explains: "VFO is an innovative next-generation packaging solution. By combining traditional wire bonding with advanced Fan-Out Wafer-Level Packaging (FOWLP) technology, we can minimize manufacturing costs without using TSV".

This means we'll have HBS using stacked DRAM and NAND, packaged with an application processor (AP) and used inside of next-generation mobile devices like smartphones and tablets. AI performance through mobile devices is a big part of the future, where SK hynix can attempt to lead the on-device AI memory market with HBS, using its VFO advanced packaging technology.

HBS isn't as intricate as HBM (High Bandwidth Memory) for the AI GPU market, as HBS doesn't require more advanced through-silicon via (TSV) packaging, where SK hynix will enjoy higher yields and lower manufacturing costs for its HBS chips.