Papers by Keyword: Laser Micromachining

Abstract: Laser cutting is one of the key fabrication technologies applied to coronary stent manufacture. This paper reviews the recent progress in laser-based stent manufacturing, including different type of lasers used, laser interaction with different stent materials, process characteristics and quality/productivity issues.

Abstract: The result of direct ablation of silicon by an 800 nm Ti:Sa femtosecond laser pulses are presented. Obtained slice of silicon with submicron roughness with tilt focused femtosecond laser pulses. Yaw cut more due to mechanical vibrations of the entire installation on a pneumatic table, but not the physics of the ongoing process. During processing, possibly thinning the silicon sample from the opposite edge (sharpening) to submicron values ​​(tens of nanometers).

Abstract: The result of direct ablation of silicon by an 800 nm Ti:Sa femtosecond laser pulses are presented. The minimum size of the crater on the silica surface ~ 250 nm was obtained, and in the central region of this crater can be identified about 170 nm in depth. In the ablation mode by single pulses received ordered structure with a length of ~ 230 nm and width of ~ 1.8 um and a period of ~ 1 um. Increasing the number of pulses without changing the focus position leads to complex and heterogeneous structure of modifications of silicon.

Abstract: Recently, interest in the study of processes occurring in the optical breakdown on the surface of solid targets associated with the increasing number of practical applications of the laser spark, such as laser induced breakdown spectroscopy and micro-and nanomaterials processing. One of the most important tasks - to reduce the diameter of the focal spot, because the size of the modifications directly related to it. However, it is not the only problem faced by the transition to sub-micron range modifications.

Abstract: This paper presents the results of experimental research on the impact assessment texture on scuffing resistance. The results showed that the texturing increases the resistance to scuffing. Above it has been shown that texture having a smaller surface energy and having a larger volume are more resistant to scuffing.

Abstract: A femtosecond laser machine consisting of femtosecond fiber laser, trepanning head, linear motor stages system and Siemens 840D system has been integrated for industry application. The femtosecond laser source is all fiber system which contains a fiber mode-lock laser at 1053 nm with a repetition rate of 3.9 MHz, a double-cladding gain fiber amplifiers and a PCF amplifier. An acoustical modulator has employed to tune repetition rate from 3.9 MHz to 100 KHz. An in-line fiber chirped grating is used to stretch the pulse duration to 700 ps. After the PCF amplifier pulse is compressed to sub-ps with 50% efficiency based two grating compressor. The system outputs an average power of 15 W at 100 KHz and 800 fs. Using four wedges trepanning head, cylinder hole is drilled in 1mm thickness SiC ceramics in 30 s.

Abstract: A novel suspended ceramic hot-plate and wire-free bonding interconnection was investigated. The device was made on the popular alumina ceramic flakes with a platinum heater prepared by lift-off process. The structure of suspended beam was machined by laser micromachining technique. This contribution presents first results for single-layer’s ceramic hot-plates that include design, manufacturing and tests of such devices. The results show that the ceramic hot-plate has lower power consumption (280 mW at 400 °C) than classical ceramic gas sensors. Moreover, it has less expensive manufacturing and bonding process than Si manufacturing technology. Low power consumption and good performance at high working temperature (600 °C or more) makes it possibly to be used in some specific applications for gas sensors.

Abstract: Laser micromachining has been widely used for decades to fabricate the micro- and submicro-component structures. However, thermal and physical damages are crucial issues associated with the process. Underwater laser ablation has been developed as a damage-free micro-ablation technique. In this paper, a comparison of the conventional dry and underwater laser micromachining of silicon is presented. It shows that the heat affected zone (HAZ) can be reduced significantly in the underwater laser process, though the material removal rate is reduced due to the energy loss by the water layer. The effects of pulse frequency, traverse speed and laser energy on the obtained kerf width, HAZ and cut surface quality are also analyzed and discussed.

Abstract: Laser micromachining has been widely used for micro-component fabrication of various materials, such as silicon substrates where silicon wafer is ablated accurately and precisely through marking, scribing, drilling or dicing. Thermal damages can occur on the substrates when improper process parameters and methods are used. This paper presents a review on the micromachining of silicon substrates using conventional and novel lasers as well as water-assisted laser micromachining technologies. The basic concepts and approaches of the technologies are discussed along with the challenges to damage-free laser micromachining at commercially acceptable cutting rates.

Abstract: The micromachining technique for the fabrication of Fe-36%Ni (Invar®) microgrooves using a novel laser-induced wet etching system with an optical fiber as the light waveguide and machining tool is investigated. Microgrooves fabricated at the optimal process conditions with the proposed etching system have good surface morphology and dimensional accuracy. It is shown that the variation of etch profiles such as etch width and depth depends significantly upon the process parameters. Fiber damage, which is attributed to macrobubbles, can be dramatically reduced by adjusting the distance between the workpiece surface and the fiber terminal. The effects of process parameters such as laser power, scan speed, and threshold distance on etch width, depth, and crosssectional profiles are reported and the optimal process conditions to fabricate Invar® microgrooves with excellent shape and size are provided. Also, the applicability of the Invar® microgrooves for the manufacturing of shadow mask for an organic light emitting diode (OLED) is demonstrated.