Development of an electrophoretic image display

The purpose of this work is to develop an X-Y addressed electrophoretic image display (DPID). At a recent DARPA/PL/ISI meeting it was agreed to increase the size of the display from 350 x 600 to 360 x 640 elements. Glass substrates with the required In2O3 thickness have been obtained commercially; it is now no longer necessary to deposit additional material. Better difinition of the row electrodes has been obtained by using this glass and using ion-beam milling rather than liquid etching. Techniques to identify and repair shorts in the row electrodes have been developed. The number of defects has been reduced by better filtration and proper outgassing of the photoresist. Aluminum spits were eliminated by using electron-beam evaporation rather than evaporation from a tungsten coil. Sputter deposition of ITO has been replaced by the more reproducible evaporation technique. To obtain better electrical contact between the display and the fan-out board, the homogeneous conductive elastomer was replaced with a laminated one. A device free of shorts or opens in the row electrodes and free of shorts between the column electrodes is now being tested.