SK Hynix, renowned for its memory semiconductor solutions, is pushing the boundaries of high bandwidth memory (HBM) technology with the development of its HBM4 16-layer products. Kang-wook Lee, Vice President in charge of PKG development at SK Hynix, has announced that the company is working on advanced MR-MUF (Massive Reflow Mold Underfill) and Hybrid Bonding technologies for its next-generation memory products.

While Hybrid Bonding offers advantages in performance, capacity, and heat dissipation due to its direct copper-to-copper connection, eliminating the traditional bumps used in semiconductor stacking, it faces challenges in technology maturity and mass production readiness. SK Hynix is rapidly advancing both technologies to address the market's demand for larger memory capacities.

MR-MUF, an in-house developed packaging technology by SK Hynix, was first applied to the third generation of HBM (HBM2E). It boasts the benefits of low-temperature bonding and batch thermal processing, offering superior production efficiency and reliability compared to other processes. The technology also features high thermal conductivity Gap-Fill materials and high-density metal bumps, providing over 30% better thermal performance than other methods.

Currently, SK Hynix utilizes MR-MUF technology in its 8-layer HBM3 and HBM3E products, with Advanced MR-MUF technology employed in 12-layer products. The company plans to adopt Advanced MR-MUF for mass production of 12-layer HBM4 products in the second half of next year. For the 16-layer products, SK Hynix is preparing both Advanced MR-MUF and Hybrid Bonding options, aiming to choose the method that best fits customer needs.

The 8-layer and 12-layer HBM3E products from SK Hynix can handle data rates of over 1.18TB per second, supporting a maximum capacity of 36GB. The upcoming HBM4 generation will offer 12-layer and 16-layer variants with a maximum capacity of 48GB and data processing speeds exceeding 1.65TB per second. Starting with HBM4, the integration of logic processes on the base die is expected to enhance performance and energy efficiency.

With the enhancement of HBM performance, the demand for HBM in the AI market is anticipated to rise. According to data from CFM Flash Memory Market, the HBM Bit supply is expected to reach 11 billion Gb this year, accounting for 4.8% of the DRAM Bit share, with a market size of $15 billion, roughly 20% of the DRAM market.

Vice President Lee also mentioned that SK Hynix is preparing to develop HBM4 and subsequent generations, evaluating various solutions including 2.5D and 3D System in Package (SiP) to tackle technical challenges in bandwidth, capacity, and energy efficiency. Furthermore, starting from HBM4E, the products are expected to offer greater customization, and SK Hynix is strengthening collaboration with global partners to build an ecosystem that effectively meets diverse customer needs.