Simulating the laser micromachining of a 3D flexible structure

Abstract

My work is to improve the generation of 3-D flexible structures by laser micromachining. The purpose is to extract the material by an ablation of matter in order to achieve ''V'' shape for multi-bend structure. This multibend part will be the key for 3-D structures. For that, a frequency multiplied Nd:YAG laser provided with a marking trigger and equipped with a galvanometric head was used. For optimizing the laser irradiation time and power a thermal modeling of the laser matter interaction for a continuous laser impact case is presented. The paper models numerically the localized three-dimensional temperature distribution in a polyimide caused by a moving Gaussian laser beam by Finite element method (FEM) analysis. The beam's penetration depth, which can be described with an absorption coefficient, depends on the ambient temperature. The model examines the penetration depth and the influences of the laser motion on the transient temperature distribution. As the maximum temperature is mesh dependent we decided to choose 10 lm initial mesh with 1.01 mesh grow, so the laser beam diameter occurs 20 lm. The overall heat flux and temperature distribution on a macroscopic level are both accurate.

Constant velocity control of a miniature pantograph with image based trajectory generation

“…As obvious from the structure of equations (15) and (12), the mapping between joint and task space is nonlinear and cannot be directly recast in a linear system. Hence, for the implementation purposes, a nonlinear solver based on NewtonRaphson iteration is used to numerically calculate the forward and inverse kinematics both for configuration and motion level.…”

Scalable Thermal Masking Technique for Postprocessing of Flexible Electronics

“…Both of these settings are specific to the laser cutter used in our laboratory and will vary based on the laser cutter model and even the condition of the same model. Gaussian beam profile of a laser beam in previous work [12,13] is defined as…”

“…where d min is the position where the intensity drops to 1/e 2 and f is the focal distance, D is the beam diameter, M 2 is the beam quality parameter, and λ is the wavelength of the Gaussian beam. The relation between absorption coefficient and temperature is given by Berenyi [13] as…”

“…Both of these settings are specific to the laser cutter used in our laboratory and will vary based on the laser cutter model and even the condition of the same model. Gaussian beam profile of a laser beam in previous work [ 12,13 ] is defined as where is the peak fluence of the laser beam, α is the absorption coefficient, and σ is the width which comes from the following equation where is the position where the intensity drops to 1/ e 2 and f is the focal distance, D is the beam diameter, is the beam quality parameter, and λ is the wavelength of the Gaussian beam. The relation between absorption coefficient and temperature is given by Berenyi [ 13 ] as …”