A flexible thin film transistor (TFT) backplane was successfully developed with Polyimide (PI) substrate and a novel de-bonding technology. The PI is colorless and transparent which can sustain a process temperature of 200 o C. With this progress, flexible organic light emitting diode (OLED) and electrophoretic display (EPD) can readily be integrated with flexible TFT backplane to fabricate flexible AMOLED and flexible AMEPD. IntroductionSince AMOLED possesses several attractive properties such as self-emissive, high video rate, wide color gamut, low power consumption, and simplicity in structure [1], it is considered most promising for flexible displays. To accomplish flexible AMOLEDs, it is required to integrate compatible processes of flexible substrate, TFT backplane, and OLED. However, development of flexible substrate and compatible de-bonding technology are presently among the most challenging tasks for the fabrication of flexible AM display. The requirements of flexible substrate include surface performance, thermal stability, reliability, and proper adhesion properties for transfer from rigid objects. Several types of substrates, including ultra-thin glass, plastic, and stainless steel have been considered as possible substrates [1-4]. Currently, the flexible substrates are mainly prepared first by either laminating or coating them on glass carriers, followed by fabricating TFT devices on the said substrates. The structure of laminating type substrate consists of metal or plastic foils (examples: PC, PET, PEN, PES, PI, etc.), adhesive glues and glass. The coating type substrate includes polymeric solutions (e.g. PI), de-bonding layers and glass. Since the drawbacks with laminating type substrate technology such as thermal expansion of adhesive glues have been widely published, we therefore decide to select the coating type substrate for our technology. However, de-bonding of flexible TFT devices is not without issues either with coating type substrate. Recently, two de-bonding methods, including EPLaR process [5-6] by Phillips and de-bonding layer (DBL) by ITRI, were developed to for the coating type substrate technology. Such advances of flexible substrate technologies will promote further growth of flexible AM displays and related applications. MethodsThe PI material is custom synthesized in ITRI, and a subject of another invited paper in this conference. The PI solution was coated after depositing DBL on glass as a flexible substrate later for AM display. The area covered by PI is intentionally made larger than that of DBL's. The glass substrate was thereafter subjected to the TFT backplane fabrication process on ITRI's Gen. 2 (370×470 mm 2 ) glass line. Top gate a-Si:H and μc-Si TFTs were fabricated by 6-mask processes and the process temperature was at 200 o C. The OLEDs were deposited and encapsulated by conventional OLED fabrication procedures. ResultsA novel flexible substrate technology compatible with the existing TFT infrastructures and processes was developed by ITRI. This technology, schema...

A 3.5-inch, 60×120 pixels, reflective-type carbon nanotube emitter field-emission display has been fabricated by thick-film process. A seven-segment numerical indicator showing digit image was also demonstrated using opposed diode structure as comparison. The technical development, including design and fabrication of the nanotube emitters, phosphor, and vacuum package process was described.

A 10-inch, 240×320 pixels, triode structure color carbon nanotube field emission display (CNT-FED) was fabricated after screen printing, photolithography and vacuum sealing process. The new normal on driving method was applied in triode CNT-FED, and the resolution was improved better than normal off FED.

Magnesium fluoride thin films were prepared by electron-beam evaporation and ion-assisted deposition (IAD). The effects of ion assistance and substrate temperature during deposition on the optical properties and microstructure were studied. The grain size, the crystallinity and the surface roughness of MgF 2 films deposited without ion assistance all decreased with substrate temperature. MgF 2 films deposited with IAD exhibited small grains, rough surfaces, fluorine deficiencies and large optical losses in the 200 -500 nm wavelength range when bombarded with argon ions.

In this paper, we proposed a novel photo sensing pixel circuit for a large-area flexible e-reader utilizing an active matrix electrophoretic display (AMEPD). The photo sensing pixel consists of only 2 amorphous Si:H (a-Si:H) transistors to achieve light sensing, pixel switching and signal amplification functions without extra driving signals. The pixel output signal is up to 2V under illuminations of a common LED laser pointer. No degradation of the pixel output performance is observed after bending of more than 5000 times under 2cm curvature radius.