MECCANISMO・LAB Achieves Wafer Bonding at 120℃ and Atmospheric Pressure, Develops 6-inch Fully Automatic Bonding Machine Based on NIMS's Technology

MECCANISMO・LAB Inc. (Headquarters: Tsukuba City, Ibaraki Prefecture; Representative Director: Tomonori Kato) has developed a fully automatic wafer bonding machine compatible with 6-inch wafers, based on the low-temperature and atmospheric-pressure bonding technology (patent registered) developed and held by the National Institute for Materials Science (NIMS). The company has confirmed the success of bonding with the actual machine.

This machine integrates a series of automated processes, from UV irradiation and ultra-thin bridge formation in an N2 environment containing vapor, to bonding in a low-temperature and atmospheric-pressure environment. A significant feature is that it achieves wafer bonding, which traditionally required high temperature and high vacuum, in a low-temperature and atmospheric-pressure environment.

*Patent No. 7018223, Registration Date: 2022.2.2

Wafer bonding machine in low-temperature and atmospheric-pressure environment (Image)

**Background of Development: Challenges in Conventional Methods and Expectations for Low-Temperature, Atmospheric-Pressure Bonding**
With the increasing sophistication and integration of semiconductor devices, the importance of bonding technology for wafers and dissimilar materials is growing year by year. However, conventional bonding processes often require high-temperature treatment and vacuum environments, leading to challenges such as thermal effects on materials, increased equipment complexity, and higher costs. This technology, which realizes bonding at low temperature and atmospheric pressure, is a new approach to these challenges and has the potential to be an effective method, especially for bonding heat-sensitive materials and dissimilar materials.

**Development Results: Confirmation of Bonding Success with 6-inch Fully Automatic Machine**
The newly developed machine is compatible with 6-inch wafers and fully automates a series of processes from wafer transfer, surface activation treatment, to bonding. In actual machine verification, successful wafer bonding at 120℃ and atmospheric pressure has been confirmed. This initiative transforms the low-temperature, atmospheric-pressure bonding process, which is being established at the research stage, into a reproducible form as an actual apparatus, marking an important step towards practical application. It has entered the verification stage for practical use, beyond research purposes.

**Key Point of Equipment Development: Integrated Design of Process and Equipment**
In low-temperature and atmospheric-pressure bonding, process conditions such as humidity, vapor density, UV irradiation conditions, and temperature significantly affect bonding quality. This machine is configured to stably control these conditions, thereby establishing a foundation for optimization according to materials and applications. Bonding quality largely depends on the combination of materials, surface state, treatment conditions, and the precision of equipment control. In this development, emphasis was placed on establishing an integrated process and equipment.

**Future Outlook: Towards Collaborative Verification for Application in Semiconductor Post-Processing and Heterogeneous Material Bonding**
This technology is not intended to replace existing bonding processes but aims to become one of the future options as a new bonding method achieved at low temperature and atmospheric pressure. New process possibilities are especially expected in wafer bonding for semiconductor post-processing and applications involving dissimilar materials. Furthermore, we are considering applications to power devices, optical devices, MEMS, sensors, and flexible materials such as film materials.

Going forward, based on NIMS's technical expertise, we will proceed with optimizing bonding conditions for each application and verifying practical applications through collaboration with semiconductor manufacturers, equipment manufacturers, material manufacturers, and research institutions. Compared to conventional equipment, it also has the potential to simplify equipment configuration and improve operability. The intellectual property rights related to the bonding process of this technology are held by NIMS, and our company, as the developer and implementer of the equipment, will contribute to the social implementation of this technology.

**Stakeholder Comments**

**[Akitsugu Shigeto, Team Leader, Smart Interface Team, Nanoarchitectonics Materials Research Center, NIMS]**
"The successful demonstration of wafer-scale bonding at full atmospheric pressure and fully automatically marks an important step towards the practical application of this technology. Moving forward, we anticipate new applications such as integration with wafer cleaning processes and the creation of functional interfaces beyond simple bonding. Furthermore, as a low-temperature and atmospheric-pressure process, we believe this technology is significant from the perspective of reducing environmental impact."

**[Tomonori Kato, Representative Director, MECCANISMO・LAB Inc.]**
"We have focused on developing the research-stage bonding process into a reproducible form as an apparatus. We believe that the characteristics of low-temperature and atmospheric pressure do not replace existing bonding technologies but have the potential to expand new application areas as one of the future options."

**Company Information**

Company Name: MECCANISMO・LAB Inc.
Headquarters: Tsukuba Research Support Center, 2-1-6 Sengen, Tsukuba City, Ibaraki Prefecture
Representative Director: Tomonori Kato
Business Activities: MECCANISMO・LAB Inc. is a company that supports mechanical design and automation equipment development, primarily in the research and semiconductor fields. We aim to solve challenges that are difficult to address with commercially available equipment.