The development of Ink Jet Printed displays (Printed Electronics 2004)

Light Emitting Polymers were discovered in Cambridge more than 10 years ago. These materials are of commercial interest to Flat Panel Display makers because they are soluble in common organic solvents and can be ink jet printed. Ink jet printing (IJP) offers a low cost, flexible and scaleable process for the fabrication of LEP-containing devices. Such devices are often referred to as PLEDs (Polymer Light Emitting Diodes). PLEDs have low drive voltages, exhibit low voltage drift on driving, are thin and lightweight, and benefit from fast switching speeds and wide viewing angles. Material lifetimes, especially for blue, and the absence of suitable ink jet printing equipment have hampered commercialisation of full colour displays. This is no longer the case. This presentation will describe the simplicity of PLED devices and summarise current material lifetimes. The key requirements of IJP will be presented together with progress made at CDT on demonstrating drop volume control, drop placement accuracy, printing at high speeds and achieving good film uniformity. Examples of IJP PLED displays will be shown. Integrated production systems and larger format printers are being built. Next generation printers incorporating multiple print heads and high speed drop inspection systems are already under development.

 

Dr Scott Brown joined CDT in May 2002. Previously he worked for Dow Corning Corporation. He is familiar with the challenges of a manufacturing environment, having spent two years at Dow Corning's manufacturing site in Carrollton, Kentucky. More recently he was based in Midland, Michigan and held the position of Global Research and Development Director for Dow Corning's Electronics Business, managing teams in Europe and Japan, as well as the US. At CDT, Scott holds the position of Vice President of Research and Technology and has responsibility to recommend and lead company wide initiatives that ensure that CDT retains leadership as a unique IP and technology provider. He is also responsible for CDT's Technology Development Centre, a 14" manufacturing pilot plant, which was built to develop and demonstrate PLED display fabrication processes. Scott has a BSc and PhD in Chemistry from the University of Exeter and an MBA from Oxford Brookes University.

Cambridge Display Technology (CDT) is the leading company in the field of polymer light emitting diodes (PLEDs) used in the global display and lighting markets.

 

CDT owns much of the basic intellectual property around PLED materials, devices and processes, and is now focussing its effort on supporting the supply chain in building the capability to supply PLED devices.

 

To date, manufacturing licences have been granted to Delta Optoelectronics, DuPont Displays, MicroEmissive Displays, OSRAM, Philips, and Seiko-Epson.

 

Founded in 1992, the company is headquartered in Cambourne, U.K. and has a PLED manufacturing development centre in Godmanchester, U.K.