Determining the optimal process conditions of micro roller embossing for large-area patterning of green ceramic substrates

Large-area (150 mm x 150 mm) patterning of green ceramic substrates was demonstrated by using micro roller embossing; micro patterns such as inductors and channels with a smallest line width of 50 mu m were formed on the green ceramic substrates. This paper focuses on process challenges and optimizations of micro roller embossing for improving the quality of large-area patterning. By increasing the embossing temperature, both the embossed depth and uniformity within a pattern unit as well as all over the substrate panel were enhanced. The defects induced during embossing were minimized by increasing the substrate thickness from four tapes to six tapes. The dimensions and locations of the embossed patterns, for instance, the channel length and unit size were characterized and compared with the designed values. The dimensions of embossed green substrates were scaled up by 0.4-0.5% in the x- and 0.6-0.8% in the y-directions against the mold. The dimensions of sintered substrate shrank by 0.6-0.7% in the x- and 0.1-0.3% in the y-direction against the green substrate. These scaling factors could be used as a guideline for actual device design and fabrication.