A 3D-CAM system for quick prototyping and microfabrication using excimer laser micromachining

Abstract

A 3D CAM tool for rapid prototyping and small-scale production of MEMS devices based on excimer laser ablation process has been developed. The system's algorithms use the 3D geometry of a microstructure, defined in a CAD model, and parameters that influence the process (etch rate, wall angle, stitching errors, etc.) to automatically generate a precise NC part program for the excimer laser machine.The performance of the system has been verified by NC part program generation for several 3D microstructures and subsequent machining trials. Stitching errors of 23.4±2.2 lm wide and 3.4±1.5 lm height were observed when overlap size between adjacent volumes were zero, when ablating 100·100 lm features in PC at fluence of 0.9 J/cm 2 using a workpiece dragging technique.When the size of the overlap was optimised by software based on optimal process parameters determined by Taguchi design of experiment method (DOE) and incorporated in the mask design the maximum stitching errors are reduced to 13.4±2.2 lm wide and 1.4±0.9 lm in height under the same conditions. Employing the hexagonal shaped mask with incorporated size of the image overlap, horizontal-stitching errors with width of 2.4±0.2 lm wide and 1.4±0.2 lm high were observed.The software simplifies part program creation and is useful for excimer laser operators who currently use a tedious trial and error process to generate microstructure parts.

Fabrication of Moulds and Dies Using Precision Laser Micromachining and Micromilling Technologies

“…When the focal point is above the material surface, the laser beam at the working distance has a significantly wider diameter and energy distribution, which is more suitable for depth controlled material removal operations and finishing processes such as laser polishing, surface treatment/modification and laser brazing [9]. In order to efficiently utilize advantages of such flexibility of the laser beam, process monitoring [10], intelligent process planning [11] and optimization of process parameters [12] are required.…”

Control of the quality of laser surface texturing

“…In the field of the high aspect ratio of micro engineering of surfaces, the laser exhibits a growing interest (Mutapcic et al 2005;Smolka et al 2004;Yongjun Lai et al 2006). A specific application is the laser surface texturing.…”