Product Code: PIC2008_M1003

Laser-assisted Hot Embossing of Microstructures
Authors:
Jens Holtkamp, Fraunhofer Institute for Laser Technology; Aachen Germany
Arnold Gillner, Fraunhofer Institute for Laser Technology; Aachen Germany
Presented at PICALO 2008

Conventional technologies for the manufacturing of micro-structured components with geometries below 100µm are injection moulding and hot embossing. Both technologies are mainly limited to polymer materials and require long cycle times since the whole forming tool has to be heated. These drawbacks can be eliminated by a newly developed laser assisted hot embossing technology, where high energy density laser radiation is used for a selective and fast heating of the tool and workpiece respectively. Using a controlled irradiation of the tool surface by high power diode lasers, tool temperatures of more than 500°C can be achieved within seconds. At this temperature even glass and metals can be structured with the new embossing technology. In comparison to other heating technologies like induction heating, materials with low thermal and electrical conductivity like ceramics can also be used for tooling. Transparent tool inserts made of sapphire enable the direct access of the radiation into the tool onto the die. Experiments were conducted with glass, polymers and metals. In the last case the radiation is directly absorbed within the workpiece. The forming die thereby penetrates into the heated metallic work piece, creating micro structures from 200nm to several 10µm at cycle times below 1minute.