Enhancing DLC micro-patterning punch for micro embossing of aluminum sheets

With the rising trend of miniaturization of multiple vital products in biomedical, semiconductor, and aerospace sectors, there is a need to fabricate high-quality micro-scale devices. The micro-embossing process has the potential to mass-produce these miniature products with high accuracy and low tolerance. In the quest to improve the micro-embossing process, 3D shaped diamond-like carbon (DLC) layer is used as a punching material due to its high mechanical properties and low frictional advantages. Furthermore, a 3D surface smoothing process is employed to reduce the roughness of the top and side walls of the 3D micro-patterns. Results show that the 3D smoothed micro-punch fabricates the designed micro-patterns onto a thin aluminum sheet with high dimensional accuracy and a low amount of defects compared to the non-smoothed micro-punch. This can be attributed to the capability of controlling the surface roughness, especially on the sidewalls of the micro-patterns, which helps in decreasing the frictional forces during the loading and unloading steps of the micro-embossing process. As a result, higher loading forces up to 20 kN of the room temperature micro-embossing process are possible with a greater filling ratio of almost 99%, which is similar to the hot micro-embossing technique.