SK hynix is reportedly likely to adopt Singapore’s ASMPT equipment for its cutting-edge fifth-generation high bandwidth memory (HBM3E) technology. Due to the nature of HBM, where DRAM chips are stacked to create the memory module, yield stability becomes more challenging as the number of layers increases. ASMPT’s equipment has received high praise from SK hynix for its ability to address these stability issues effectively.
According to industry sources on Feb. 26, SK hynix has ordered TC bonder equipment from ASMPT and is testing it on various HBM products, including the 16-layer HBM3E. The TC bonder, a crucial tool in the HBM manufacturing process, is used to stack chips vertically. SK hynix’s method involves repeatedly lifting the chip dies slightly with the TC bonder, followed by a mass reflow (MR) process to bond the chips, and then an underfill process for insulation. This process is referred to by SK hynix as MR-MUF (Molded Underfill).
Earlier in January at CES 2025 in Las Vegas, SK Hynix reportedly showcased its 16-layer HBM3E product manufactured using ASMPT equipment. The 16-layer HBM3E is considered a transitional product between the 12-layer HBM3E and the next-generation HBM4. With major tech companies like Meta and Google developing custom AI chips and requesting tailored HBM4 products, the 16-layer HBM3E could serve as a key alternative before HBM4 reaches commercialization.
An industry insider said, “Since HBM4 will be developed in a more customized manner, some customers may opt for the more versatile HBM3E. Additionally, with the emergence of lower-cost AI models like DeepSeek, demand for the more affordable HBM3E lineup may persist longer than expected.”
SK Hynix, the world’s top HBM supplier, has long relied on South Korea’s Hanmi Semiconductor for its TC bonder equipment. However, the company has been diversifying its equipment suppliers, with ASMPT emerging as a key candidate alongside Hanwha Semitech, which is actively developing TC bonder technology. Some industry observers believe SK Hynix has already deployed around 30 ASMPT machines at its production lines since last year.
As the number of HBM layers increases, bonding equipment becomes even more critical. For example, in the 12-layer HBM3E process, the thinner chip dies require slight heat application during bonding to prevent warpage before undergoing mass reflow. SK Hynix refers to this technique as heated Mass Reflow (hMR).
A source familiar with SK Hynix commented, “In simulations of the HBM3E 16-layer process, ASMPT equipment has outperformed Hanmi Semiconductor’s machines as the layer count increases,” adding, “The use of ASMPT’s equipment for the 16-layer HBM3E showcased at CES 2025 appears to be related to these findings.”
