Laser-induced thermochemical wet etching of titanium foil for fabrication of microstructures

Abstract

Laser-induced thermochemical wet etching of titanium in phosphoric acid was conducted for various conditions to examine the feasibility of this method to fabricate three dimensional micro structures. Drilling, milling, and cutting of titanium foil were carried out while examining the influence of process parameters on etch width, etch depth, etch rate, and edge straightness. Laser power density, scanning speed of the workpiece, and the concentration of etchant were chosen as the major process parameters since they directly determine temperature distribution on the sample surface and the reaction rate. A finer groove was obtained by reducing the laser power and for a typical groove width of 20 micrometer was reached for single path scanning. Etch width increased almost linearly with laser power showing little dependence on scanning speed. Etch depth, however, showed wide variation with both laser power and scanning speed. Fabrication of micro cantilever beam, hole, and rectangular structure were demonstrated.Laser-induced thermochemical wet etching of titanium in phosphoric acid was conducted for various conditions to examine the feasibility of this method to fabricate three dimensional micro structures. Drilling, milling, and cutting of titanium foil were carried out while examining the influence of process parameters on etch width, etch depth, etch rate, and edge straightness. Laser power density, scanning speed of the workpiece, and the concentration of etchant were chosen as the major process parameters since they directly determine temperature distribution on the sample surface and the reaction rate. A finer groove was obtained by reducing the laser power and for a typical groove width of 20 micrometer was reached for single path scanning. Etch width increased almost linearly with laser power showing little dependence on scanning speed. Etch depth, however, showed wide variation with both laser power and scanning speed. Fabrication of micro cantilever beam, hole, and rectangular structure were demonstrated.