Micro‐Laser Processing

Abstract

INTRODUCTIONThe use of laser technology in the processing of materials for micro-products has been reported over the last decade. Laser-based material processing on a microscale has been used in thermal processing, shock peening, surface treatment, cleaning of surfaces, welding, melting and polishing, scribing, as well as micromachining of basic geometric features on a variety of materials [1][2][3][4][5][6][7][8][9][10][11][12].Lasers are usually categorized as two groups: continuous wave (cw) and pulsed lasers. Conventional cw and pulsed laser irradiation and ablation is used in many fields, such as material processing, machining, etching, deposition, sintering, micro-fluidics, medical, and many other applications [13][14][15][16][17][18][19].The use of lasers in micro-manufacturing is closely connected to the characteristics of the laser. The main laser parameters to be chosen and controlled are wavelength, λ (nm); average power (W) or energy (J); intensity (W/m 2 ) or fluence, ( ) (J/m 2 ); pulse duration, τ (s); pulse repetition rates (Hz); and peak power (pulse energy/pulse duration) [9,11,16,20,21].Pulsed lasers achieve much higher intensities than cw lasers and are the preferred solution for the fabrication of micro-sized structures. Long-pulsed (nanosecond, ns), short-pulsed (picoseconds, ps), and ultrashort-pulsed (femtosecond, fs) lasers that are commonly used for repairing, trimming, marking, scribing, texturing, welding, ablation, cutting, and drilling include among others (i) Excimer lasers with ultraviolet (UV) wavelengths, (ii) Ti:sapphire lasers Micro-Manufacturing: Design and Manufacturing of Micro-Products, First Edition. Edited by Muammer Koç and TugrulÖzel.

Technology maturity assessment of micro and nano manufacturing processes and process chains

“…With regard to PS laser ablation, it is rated as a borderline case (41%) between a ‘Repeatable’ process, ML 2, and a ‘Defined’ process, ML 3, in spite of the fact that it is currently commercially exploited and significant R&D efforts have been put in its development. 48 Nevertheless, it is generally accepted that for this process, various open issues remain with respect to the following: the modelling and simulation of laser–material interactions, 48,49 the empirical character of the process optimization, the predictability of the process performance and the necessity for further optimization of material removal strategies. 50 Therefore, within this context, the PS laser’s overall ML appears to be a realistic judgement of its current state of development.…”

Effects of Laser Fluence and Pulse Overlap on Machining of Microchannels in Alumina Ceramics Using an Nd:YAG Laser

“…In contrast non-conventional machining methods like micro-electric-discharge machining (Micro-EDM), micro-ultrasonic machining (Micro-USM), and micro-laser-beam machining (Micro-LBM) are able to produce extremely fine accuracy and better surface integrity with little or no tool wear. Specifically, Micro-LBM is an excellent choice for machining ceramic parts as it provides better process control, improved dimensional accuracy, and easier set-up in comparison to other methods [6].…”