Morris - Manufacture of Really Reflective Information Surfaces

‘Morris’ is a 3 year program to develop large area (~1m diagonal and up), reflective colour display surfaces, made by printed/plastic electronic processes, for use in applications such as command/control rooms, electronic whiteboards, posters and signage, and architectural/ interior design (electronic wallpaper). The partners are Hewlett-Packard, Timsons Ltd, and PETEC (CPI Ltd). The final output will be the specification of a pilot line and material set, projected costs and yields, and demonstration devices, components, processes and equipment; to be sufficient to secure investment in pilot and then full manufacturing.
Morris is based on a novel, industry leading approach to reflective colour, particularly applicable to large area plastic displays; innovative highly transparent and highly conducting structured electrodes, and advances in organic semiconductors/TFT fabrication processes. These will be developed and integrated, focusing on performance, yield and cost. The partners and subcontractors cover key areas of the developing UK Plastic Electronics supply chain.
The colour reflective display is enabled by the use of novel optical reflectors sandwiched between coloured electro-optic modulation arrays. A significant part of the project is to develop new, cost effective means of fabricating these optical enhancement layers, and develop improved EO modes to form the displayed image. The optical performance approaches that of print, a SNAP print quality is obtainable. Work on new colourant synthesis in the UK has been contracted, and this work will have benefits for many display applications. Colour reflective displays are particularly suited for outdoor use, so the requirements and demonstration of lightfastness is important.
To enable a reflective display, the optical losses must be minimized. To enable active matrix addressing of the pixels to give complex imaging at high speed, the array must have a small optical footprint, and the semiconductor material be of sufficient performance to give a small device. Previously, optical apertures of ~90% have been demonstrated, but this is not high enough, under the Morris project arrays of >95% aperture are being fabricated using novel electrodeposited materials and techniques.
A range of organic semiconductor materials are being evaluated from suppliers within and external to the project, from the UK, Europe and the US. This gives the project the opportunity to select the most appropriate materials set for each application targeted. Under the project, class leading device performance has been demonstrated in useful devices.
The third strand of work under Morris is to develop a scalable approach to plastic substrate handling. Historically, plastic substrates have either been handled as sheet materials, laminated to rigid carriers and put through existing wafer and panel equipment, or have been processed in a full scale roll to roll fashion. The former does not scale easily to larger area, and has cost drawbacks, the later has yet to demonstrate high areal yield for complex functional devices. A clean spool cassette system, similar to the approach taken in wafer fab FOUPs, is being developed, where a 20-30m length of film at up to 650mm width can be handled without the front surface ever coming in contact with the equipment or the rest of the film material. As the cassettes are self contained, processing equipment can be designed in a modular fashion, without the need for materials feed rate matching. Sensitive coatings and lithography can be carried out without mechanical damage or contamination. Spool cassette equipment will be prototyped and the performance of the cassette handling verified during the Morris programme, this will then form the basis of a common means of handling, transporting and processing film in the plastic electronics industry, scalable from R&D to pilot and initial volume manufacturing.
The Morris programme will also investigate the development of new applications and exploitation routes for plastic, reflective colour displays and other plastic electronics systems, with the aim to put the UK at the forefront of development of underlying science, implementation technology and process equipment development. Plastic reflective colour displays are inherently low power, have low materials usage, and are processed at low temperatures, leading to reduced environmental footprints in manufacture, use and end of life.