When developing innovative hi-tech electronic products, companies often need temporary, on demand manufacturing facilities. Moorfield Associates explains how its solution – a portable cleanroom tent – helped hi-tech company Nano ePrint meet its project timescales.
Printed electronics has been talked about for many years and is now promising to be the next big wave of the electronics industry. The ability to “print” functionality, which today would require a large silicon fab, is seen as enabling a huge range of new products and applications, driven by the extremely low cost of printing compared with traditional silicon wafer processes, and by the greater range of physical form factors enabled by robust, transparent thin-film semiconductors on flexible plastic or paper substrates. Nano ePrint (www.nanoeprint.com) fabricates electronic devices in a single layer of thin-film semiconductor, deposited on a flexible substrate via a single-step patterning approach. The patterning is performed using nano-embossing, analogous to the earliest forms of printing (wood block, letterpress, etc) but on a much finer scale. This printing process is compatible with roll-to-roll, and has been in use commercially for around 20 years for the production of optical microstructures (such as the security holograms that are embedded in modern banknotes and passports).
As a spin-out company, Nano ePrint has worked closely with the University of Manchester and UMIP, the University’s commercialisation company, since its inception. Following the most recent investment round in November 2008, Nano ePrint established its own facility outside the University of Manchester within the Manchester Incubator Building, managed by the University of Manchester Incubator Company (UMIC). Much of the equipment and tools can be translated directly from security printing – although, as with other printed electronics technologies, this demands higher requirements for cleanliness and environ-mental control than conventional printing.
Seeking a rapid start-up and fit-out of this facility, Nano ePrint required a low-cost and easy-to-install cleanroom solution. This requirement led the company to Moorfield Associates, which manufactures a portable cleanroom called “Clean-Tent”.
Nano ePrint’s vice-president of product management, Richard Price, recalls this process: “We looked at a range of options, including standard cleanroom construction. However, we needed to ensure a rapid set-up and minimise disruption in the transfer from the University. Standard cleanrooms were not only very expensive but would also have taken many months to install. The simplicity and flexibility of the Clean-Tent was ideal for a company at our stage and we were up and running within a matter of weeks. “We’ve already expanded from a few people in the University laboratories to 12 people working on various aspects of our product development. We expect substantial further growth this year and this will need larger facilities. “With the Clean-Tent we’ll be able to simply deflate, pack up and reinstall within a few days. This will dramatically simplify any disruption and minimise downtime, which will be good news for our investors and customers.”
The simplicity of the Clean-Tent product is its strength. The tent is a single skin fabric with two compartments: one for the gowning room, the other for the cleanroom proper. The tent is manufactured in two parts – the ground sheet, over which a vinyl antistatic floor can be laid, and the top tent, which attaches to the ground sheet via a continuous zip.
There is a bulkhead between the two compartments. Zips allow entry into the gowning room and through the bulkhead into the cleanroom. These are arranged such that the path through the gowning room is diagonally across it, allowing for the placement of a stepover bench en route. The set up is therefore standard protocol with black, grey and white allocated areas – all familiar territory to cleanroom users. What makes the Clean-Tent unique is its structural form. The HEPA bank is sited on a framework and attached to the gable end of the tent on the cleanroom side, thus giving horizontal laminar flow through the cleanroom. The air flow also provides the stability to the structure as the positive pressure actually inflates the cleantent. The entry/exit zips also act as exhaust ducts and control the cascade differential pressure between the two compartments and ambient. A fan speed controller maintains HEPA face velocity. The product is capable of accreditation at ISO5 (Class 100) levels, but Moorfield cautiously specifies the Clean-Tent at ISO6 (Class 1000). Moorfield’s managing director, Jon Whitehead, explains: “Many of our customers are new to cleanroom technology and unfamiliar with related procedures such as wipe down routines. We therefore classified the Clean-Tent at a lower level than it can actually achieve to accommodate them. If we are required to perform installation of the Clean-Tent we always attain ISO5 particulate standard before we leave site.” Nano ePrint sees itself as a device company and builds on the core expertise and know-how of the founding University team, led by nanoelectronics expert Professor Aimin Song. Nano ePrint intends to sell printed electronic circuits, with a particular focus on programmable logic that can be easily configured for multiple applications.
The company expects to roll-out its first commercial printed logic product in early 2010. Price believes Moorfield’s Clean-Tent is a good fit with printed electronics. “The beauty of printed electronics is that it compatible with a fab-in-a-box approach,” he says. “The Moorfield Clean-Tent can help lots of entrants to get started in printed electronics without needing to invest in large, expensive cleanroom facilities used in conventional silicon electronics. We’ll certainly be recommending this to our customers and partners.” CT
CONTACT
Moorfield Associates Moorfield House Plumley Moor Road Plumley Knutsford Cheshire, WA16 9RS UK • T +44 1565 722609 • F +44 1565 722758 • sales@cleantent.co.uk • www.cleantent.co.uk