Laser direct writing lithography for rapid fabrication on non-planar surfaces Available to Purchase

A modified laser direct writing lithography system with dynamic focusing is presented. This improved system can realize rapid fabrication on non-planar surfaces with large curvature and it offers new possibilities for fabricating micro-patterns on curved surfaces in an easy and fast way. A dynamic focusing lens group which is driven by a linear voice coil motor is introduced and it can rapidly control the laser spot to focus on the curved surface when processing in real-time. The focus range is almost 10 mm and it can be larger when working with the z-stage. The mathematic expression of dynamic focusing is deduced and the corresponding experiment results agree with the numerical analysis, which shows the practicability of the system. The effects of slopes with different tilted angles on exposure linewidth are studied. Finally, a concentric-circle grating is fabricated on a convex substrate with a diameter of 30 mm and a radius of curvature of 19.918 mm. The grating has homogeneous linewidth of 10 µm and line space of 20 µm, and the total processing time is within 40s. This technique can greatly improve the efficiency and has great potentials, such as rapid fabrication of diffractive optical elements (DOEs) or microelectromechanical systems (MEMS) on arbitrary 3D curved surfaces.