AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP61
Jet-printed Organic Electronics: Display Backplanes without Vacuum Processing

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: J.H. Daniel, Palo Alto Research Center
Authors: J.H. Daniel, Palo Alto Research Center
A.C. Arias, Palo Alto Research Center
B. Krusor, Palo Alto Research Center
R.A. Street, Palo Alto Research Center
Correspondent: Click to Email
Most electronic circuit fabrication relies on vacuum tools for the deposition or removal of materials. In large-area electronics, particularly for active-matrix display backplanes, these vacuum tools represent a considerably increased engineering challenge due the growing substrate size and the requirements on uniformity. Moreover, the capital cost is substantial. With the development of new materials, solution-based processes are being studied which will potentially enable extremely low-cost large-area electronics on flexible substrates. We are investigating low-temperature (<150degC) all-additive processes for the fabrication of flexible active matrix thin-film transistor (TFT) backplanes. The metal conductors for gate/data lines and pixel pads are defined by jet-printing of silver nano-particle solutions. The active regions of the TFTs consist of jet-printed polymeric semiconductor (PQT-12). Various polymeric gate dielectrics were investigated, including the epoxy SU-8. SU-8 strongly cross-links at temperatures below 150 degC making it chemically inert to subsequent processing steps and the surface energy of SU-8 is compatible with the printing solution to form narrow continuous lines. We were able to coat SU-8 layers with a thickness around 200-300nm with low pin-hole density. Pixel circuits were printed on rigid and flexible substrates. The transistor performance was measured and the pixel response was determined using a picoprobe. When combined with our reflective electrophoretic display media these all-printed backplanes are promising for electronic paper or signage applications.