Free magazine about direct-write lithography and its applications in research and industry.
Maskless Aligners for industry, part 2
An opto-mechanical masterpiece
Interview with Steffen Diez
Dec 11, 2020
You can read the first part of the interview "The first real alternative to Mask Aligners" here.
Did this interest motivate the development of the industrial MLA?
Steffen Diez: We planned to develop an industrial version of a maskless aligner back when we began working on the MLA concept. Due to limited R&D resources, we prioritized the work on the MLA150. This turned out to be a good choice because we could fully develop the core technology and learn from our industrial MLA150 users what the tool really needed to improve in order to fulfil their requirements. The MLA150 is optimized for R&D: The software is designed for handling small lots and for easy tracking of project status, not for high-volume production. The exposure time is excellent for research applications, but it is not fast enough for commercial production. There was no automation, either.
MLA300 is a completely new machine, so we could meet all the needs of our industrial customers, which extended far beyond just higher throughput:
- A massively increased throughput as compared to the MLA150;
- The MLA300 can be fully automated, including substrate handling and loading, and interfacing to manufacturing execution systems (MES);
- It is a fully integrated and modular machine with a minimal, yet flexible footprint. This concept simplifies service and allows a fast "plug and play" installation;
- The software interface and usability concept were developed with the help and feedback from a customer, this time from industry.
SEM image of a structure written using MLA technology. Images courtesy of CMi (EPFL Center of MicroNanoTechnology)
Our R&D team really pushed the limits of direct-write lithography. We are very proud of the MLA300. It is the most advanced tool we have ever built. It is unique in many ways, and it is also the only production-ready solution for industrial micro-fabrication currently available in the market.
What were the key design challenges?
After some calculations, we realized that we couldn't achieve the required speed with only one optical engine. So we embarked on one of our most demanding R&D projects ever: The development of a fully integrated optic module. Our optical designers and construction engineers created an opto-mechanical masterpiece. The MLA300 system is designed for the integration of up to four optic modules. It is even possible to integrate modules with different wavelengths or different resolutions. That means you can customize the MLA300 according to the specific application requirements in terms of resolution, write-speed and substrate handling.
SEM images of different structures patterned using MLA technology. Images courtesy of CMi (EPFL Center of MicroNanoTechnology)
What kind of applications can benefit from MLA300?
At the moment, we focus on applications where maskless lithography has a significant advantage, for example, warped substrates. Such deformations commonly occur in applications which use a stack of materials with different thermal expansion. The warpage can measure up to 300 µm. Our system is able to compensate warpage with the real-time autofocus system. Other niche applications demand a flexible adaption of the pattern, a requirement which is efficiently met by the MLA300 system. We aim to ultimately place the system in high-volume applications such as wafer-level packaging, MEMS fabrication or LED production. One of our customers has already begun using MLA300 in a pre-production environment. We are now integrating the tool into their production line to make it their standard exposure machine. Since the official launch of the MLA300 in November 2019, we have already received multiple orders for the system. The fast order intake confirms that the flexibility and superior exposure quality on challenging substrates is a large unmet need for industrial production customers.
Read more about MLA300 specifications or download the fact sheet here.
We look forward to discuss our products and services with you.