Characteristics of 3D microstructures fabricated using a modified LIFT process

A direct writing Laser Induced Forward Transfer (LIFT) process has been applied to various aspects of micromachining processes such as circuit interconnects, microelectronics, and mask repairs. LIFT processing with a polymer coating layer is a promising technique used to deposit micro-size feature and electric circuits. As a laser direct writing technique, the LIFT technique has been applied to micropatterning. However, the geometric accuracy and electrical conductivity of micropatterns fabricated by LIFT are limited. In this study, these difficulties are resolved by depositing 3D conductive microelectrodes on microchannel sidewalls by LIFT, during which process a metal thin film (Cr, Cu) is coated with a polymer (AZ 1512) according to the channel geometry profile. LIFT is carried out under ambient atmospheric conditions. The proposed LIFT technology contributes to the deposition of microelectrodes with geometric accuracy by printing electric circuits with improved electrical conductivity. The surface morphology of the transferred micro-patterns is observed by SEM and an optical surface profiler (Zygo).