A Novel Image Trimming Algorithm for IJP Fabrication in Line Width and Layer Thickness Compromise

Abstract

To brew ink-jet printing (IJP) technology instead of traditional processes like spinning, screen printing, photolithography, and laser printing, used for semiconductor and display field, what is the obstacle before make mass production? The tunable resolution for image compensation and thickness control is the highest priority due to they dominate the device performance and need carefully control. For examples, the metal circuit will be in tunable resolution up to ± 3 um for high level IC carrier board, to correct the image deterioration caused during prior layering process. However, the innate characteristics of IJP transfer the raster image data format restrict its development due to the resolution is non-tunable in such fine resolution, or it need overlap drop-to-drop in ultra accuracy, to complete the narrow line width requirement. But this strategy conflicts with the layer thickness while highly drop-to-drop overlay, it will increase the layer thickness and spreading the line width synchronously, make it is hard to control the line and layer quality expected. This paper proposed a novel image trimming method to transfer original image to trimmed image based on the spreading factor between the liquid-solid interface and the assumption of linear superposition for drop-to-drop overlapping, as well as versatile filtering function built as look-up table in auxiliary to modulate layer thickness. In details, the trimming method included the procedure of pattern identification and locating, image separation, seamless image merge, image boundary compensation, image trimming on spreading factor, and image reconstruction, and the filtering method included the local characteristic of boundary inspection with defined correcting function and varied filtering pattern applied to inner field of boundary. The test pattern found the resolution can be step tuning of ± 5 um at 100um line width requirement for 10 pl IJP dispensing, and got satisfactory thickness as expectation.