Laser machining of silicon nitride based composite cantilever structures

Cantilever structures from silicon nitride based composite ceramic materials were produced using laser cutting. A picosecond laser was used to cut two-dimensional meso sized cantilever structures up to 450 μm thickness in conductive and insulating ceramics. A practical experimental based approach was used, where various parameters of the laser cutting process were altered to produce a cut surface with a damage zone of 5–10 μm. The quality of the cut ceramics was investigated by optical and scanning electron microscopy. The results are presented along with the properties of the laser cut surface, including the damage zone, formation of cracks and the reaction products.

► MEMS cantilevers of Si3N4 ceramics up to 450 μm thickness have been successfully laser machined.
► The damage by laser cutting on the ceramic surface was examined by optical and SEM.
► Laser parameters were varied until the damage was less than 5–10 μm.
► This is similar or less than inherent flaws from ceramic processing technology.