Laser Induced Thermal Imaging (LITI) allows for high-resolution patterning of a variety of materials that often cannot be patterned efficiently by other conventional techniques such as photolithography. Application of LITI towards patterning vacuum-coated OLED materials is particularly attractive because of high LITI patterning resolution and accuracy and good compatibility of vacuum-coated OLED materials. However, LITI may induce thermal transfer defects within OLED materials. We are developing methods to address these potential thermal defects while maintaining patterning quality, device operation efficiency, voltage, and lifetime. Recent results regarding optimization of LITI for patterning vacuum-coated OLEDs will be discussed.
Laser Induced Thermal Imaging (LITI) is a high resolution, digital patterning technique developed at 3M for use in a number of applications including the patterning of LCD color filters and OLED emitters. The LITI process is suited for the manufacture of flat panel displays, where both high resolution and absolute placement accuracy are required. In this paper, we present the capabilities of LITI, the basic design of a LITI laser imager, the construction of a LITI donor sheet, and the process by which OLED emitters may be patterned. An OLED device fabricated with the LITI process is described.