Micromecanizado mediante láseres de femtosegundos de cerámicas LTCC. Fabricación de microcalentadores para un sensor de monóxido de carbono

Abstract

In present work, the processability of LTCC (Low Temperature Co-fired Ceramics) by means of femtosecond laser ablation is shown. This kind of material, with a clear technological interest in the development of microsensors, possesses a high mechanical fragility in the sintered state and, consequently, contact methods for micromaching (micromilling, microgrinding, etc.) lead to fracture or the appearance of microcracks. The paper has been structured in two different parts. Firstly, a detailed study of the process has been performed, obtaining the fundamental parameters, as ablation threshold and incubation factor and a parametrization of width and height of microchannels as a function of fluence and feedrate. Afterwards, these results have allowed the fabrication of simple structures as boxes, passing-through holes and 2 1/2 D structures. Finally, the technological interest of the material and the process is shown. This way, microheaters in LTCC have been fabricated as initial stage of a carbon monoxide chemoresistive sensor. The system allows the heating of a 1mm × 1mm area up to 490°C with almost no heat dissipation to the surrounding area.