Micro structuring of inorganic glass by hot embossing of coated glass wafers
Hot embossing is an economical manufacturing process for structuring of glass. However, this process is limited by sticking of glass melts on the moulding tools. In order to prevent this problem, the glass substrate was coated with thin metal, carbon and oxide layers. In the current work, the behaviour and suitability of the coatings for the embossing process were investigated. As a result, it was found that all coatings showed a clear decrease of adhesive forces and an increase of sticking temperature out of the range relevant for hot embossing. The examined coatings behave ductile, however, under larger elongations they tend to crack. Examples of fluidic structures with lateral geometries in millimetre and micrometre range were realized. The coatings could be successfully applied in moulding experiments without reduction of quality of embossed structures by sticking of the glass melts. The largest aspect ratio of embossing depth to structural width amounted to 3.