New cooperation model? TSMC outsourced part of the CoWoS process to OSAT

According to industry sources, TSMC has outsourced some of the processes of its CoWoS packaging business to OSAT, such as Sun and Moon, Silicon products and Anqu, especially in small batch customization products.

CoWoS (Chip On Wafer On Substrate) is a 2.5D packaging technology, which first connects the chip to the silicon wafer through the packaging process of Chip on Wafer (CoW), and then connects the CoW chip to the substrate (On Substrate, referred to as oS).

According to the Electronic Times, for some high-performance chips that require small batch production, TSMC only handles the CoW process at the wafer level, while a similar cooperation model for outsourcing the oS process to OSATs, is expected to continue in future 3D IC packages.

The basis of this model is that TSMC has highly automated wafer-level packaging technology, while there are relatively more parts of the oS process that cannot be automated and require more manpower, and OSAT has more experience in handling oS processes, which leads TSMC to outsource this part of the process.

In fact, in the past 2-3 years, TSMC has successively outsourced part of the oS process of packaging business to the above-mentioned enterprises, including silicon intermediate layer integrated or fan-out wafer-level packaging (FOWLP), and various HPC chips that need to be produced in small quantities using CoWoS or InFO_oS packaging processes.

Sources said that for TSMC, apart from advanced technology, the most profitable business is wafer-level SiP technology, such as CoW and WoW, followed by fan-out and intermediary layer integration, and oS has the lowest profit. Due to the significant increase in the demand for heterogeneous chip integration, TSMC is expected to adopt a more flexible model to cooperate with OSATs.

The person stressed that even if TSMC's latest SoIC technology is widely used in the future, the cooperation between foundry and OSATs will continue, because SoIC, like CoWoS, will eventually produce "wafer-shaped" chips that can integrate heterogeneous or homogeneous chips.

According to the source, TSMC also uses InFO_PoP technology without a substrate to encapsulate iPhone APs manufactured by advanced process nodes, and strong integrated manufacturing services help to secure a large number of orders from Apple.