5 key UPMU workshop takeaways: UPW system design principles

UPM University rounded off 2023 with an interactive workshop on the design principles that underpin ultrapure water (UPW) systems for semiconductor fabs. Participants worked on case studies to design two different UPW systems, supported by the guiding hand of experts Slava Libman, CEO of FTD Solutions, and Chuck Dale, semiconductor UPW technology leader at Veolia Water Technologies & Solutions

System design begins by analyzing the boundaries within which a UPW system must work - here are five key considerations around UPW system design that participants analyzed during the workshop.

1. Product type

One key consideration for UPW system design is the desired outputs of the facility that the system will be supplying. Participants worked on two case studies during this workshop – one group proposed a process flow diagram for a leading IC manufacturing company, while the other group considered the production of UPW for boiler feedwater in a smaller, low risk system when making their process flow diagram. Advanced UPW systems will have to reckon with the challenge of particle precursors, which current ultrafiltration technology is not equipped to deal with.

2. Incoming water quality

Understanding incoming water quality is critical for UPW system design, as it gives insight into the types of contaminants in the water. Instructors provided key assumptions of water source and treatment level for each case study – for one, water supply came from well water, while the other case study assumed surface water as its source, and therefore salinity level and treatment train varied between the two types of water. The resulting process flow diagrams produced by the two groups differed according to these distinct characteristics.

3. Operational considerations

When considering UPW system design, participants had to account for various features of the facility in their case study. In addition to product type, the size of facility fed by a UPW system influences the volume of water required, the size of the UPW tank and the flow rate. Operational requirements are also a relevant consideration – for one of the case studies, continuous operation was assumed (24/7) while for the other it was assumed that the facility would run based around 8-hour shifts, five days a week.

4. Environmental considerations

Increasingly, environmental considerations such as lowering chemical and energy consumption are driving decisions between different polishing systems. For example, electrodeionization could be the preferred option as opposed to ion exchange due to the latter’s use of resins. For one of the case studies, which looked at an advanced semiconductor production process, participants’ decisions were informed by the additional consideration of a low environmental footprint. 

5. Water recovery

Water flow rate impacts the requirements for water recovery from processes such as reverse osmosis. If the flow rate is higher, then more recovery is needed to retain the same quantity of water, whereas a system with a slower flow rate may not need high recovery reverse osmosis. Participants weighed up the necessity of water recovery against factors such as flow rate, volume of water and potential ESG goals.

When approaching process design, workshop participants considered several different objectives simultaneously and worked to understand the context before addressing the actual process. As Chuck Dale aptly put it, "before a train leaves the station it's very important to understand where a train needs to call, what sort of rails it's on, and its final destination."

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Register your interest in UPMU by contacting Guillaume Crompton-Roberts at g.cromptonroberts@globalwaterintel.com.