Papers by Keyword: Micro Machining

Abstract: A newly designed arc-form shaped tool was used to carry out precise micro electrochemical etching (MECE) to remove Indium-tin-oxide (In2O3SnO2) thin-film nanostructures from the optical PET diaphragm surfaces for digital-paper surface. For this precise removal process, a higher current with a faster feed rate of the optical PET diaphragm effectively achieved rapid material removal. A pulsed direct current can improve dregs discharge and is advantageous when associated with fast PET feed rates, but this raises the total current required. A higher temperature or flow velocity of the electrolyte corresponds to a higher removal rate of the In2O3SnO2 nanostructures. A high rotational speed of the arc-form shaped tool corresponds to a higher removal rate of In2O3SnO2. A large cathode, along with a small gap-width between the cathode and the PET diaphragm, increases In2O3SnO2 removal rates. A thin cathode, or a short arc length of the arc-form anode, reduces the time taken for In2O3SnO2 removal.

Abstract: Moore’s law by scaling conventional CMOS involves huge lots of technology evolution in both aspects of electronics material and micromachining. One of the most promising modern innovations is the 3D IC and the key material to the 3D IC is the low-K (dielectric) materials. Since the new generation low-K material is rather porous and fragile in structure strength, conventional singulation methods including the dicing saw and nano-second laser can not be applied. New machine modality has to be used to avoid the cracking and excessive debris contamination. In this paper we demonstrate the application of pico-second laser on the grooving machining of low-K wafer. The results show that the removal of low-K material is up to the production standard: smooth groove bottom with minimal debris. However, as the groove line involves metal pads the laser power is partially consumed by the ablation of the metallic material the depth is not controlled ideally. With proper adjustment of the machine parameter such as laser power, focal depth and pulse energy the problem can be resolved.

Abstract: We present the fabrication of submicron polyimide film sandwiched by Al film. The preparation in two-step method and spin-coating parameters of submicron polyimide film are described. To achieve self-supported structure, thick nickel mesh (ca. 200 μm) was introduced by micro-electroforming. Using negative tone photoresist SU-8 2150, the nickel grid width was demonstrated in good agreement with its original design value with optical microscopy.

Abstract: Abrasive air jet micro-machining is a new promising technology for processing brittle material. An experimental study of micro-channeling on quartz crystals using an abrasive air jet is presented. The effect of the processing parameters on the produced channel profile such as the channel width, depth and kerf taper angle is analyzed, along with the effect on the roughness of channel bottom surfaces. Plausible trends of the major process performance measures with respect to the process parameters have been revealed. These trends are useful in guiding the selection of process parameters in practice.

Abstract: This paper discusses burr in microdrilling that affect forms and functions of parts. The effects of microdrilling parameters on burr length and width are identified. The experiment was conducted using Mikrotools DT110 machine with one millimetre diameter of HSS on copper workpiece. Burr heights in terms of burr length and burr width were measured by using scanning electron microscope. The data was analyzed using Taguchi method to find the optimum micro-drilling process parameter for minimizing the burr height. The relationship among spindle speed, feed rate and burr has been developed. It is found that feed rate is the most influential factors on the burr height. The desirability of getting the minimum burr height is 72% and the optimum parameters are 30000 rpm spindle speed and 0.2 mm/min feed rate.

Abstract: Owing to drilling capacity can reach micron grade, laser punching technology has been widely used in high-tech field. In this article, ultraviolet laser has been adopted to punch on polystyrene material, the ablation principle and heat transfer between ultraviolet laser and material are analyzed. Through the finite element simulation, microporous temperature field distribution can be obtained. At last, by experiments that use single factor method to get laser parameters on the effect of surface morphology and microporous depth/diameter ratio, the optimal laser parameters that satisfy requirements which are less slag and tapered micropore can be acquired.

Abstract: Since micro products have become smaller, the requirements concerning precision and accuracy for producing machine tools to manufacture such small parts increased. Consequently, each component of a machine tool needs to conform to these requirements. A flexure-based feed unit, a clamping system and mechanical couplings are briefly presented. These components can quickly be reconfigured, which allows for a new modular micro machine tool system. Each component incorporates individual precision and accuracy leading to an overall error budget for a machine tool system. This is methodically addressed in the contribution.

Abstract: Micro plastic structures, typified by photoresists for semiconductor devices or various MEMS devices, photosensitive resins of microstereolithography, and so on, play one of the most important roles in the microdevices manufacturing. In order to process finer plastic structures with higher reliability for more complexly-modulated microdevices in the next generation micromanufacturing field, a nano removal processing method, which can be applied to a corrective machining process with the removal resolution less than 10nm in both lateral and vertical direction, is strongly required. In this study, we propose a novel nano removal processing method for micro plastic structures with photocatalyzed oxidation. Here, we apply photocatalysts micro particles as a specially designed material removal tool tip. Since a light energy is not directly used for processing the material, a material removal resolution does not depend on the diffraction limit. Further, using photocatalysts is free from micro tool wear problem. As the first report, in order to verify the fundamental feasibility of the proposed method, we performed basic experiments using TiO₂ micro particles with the diameter of 500nm for cured photosensitive resin surface. An AFM observation of the processed surface showed that a vertical removal resolution of 8nm was achieved.

Abstract: This paper describes micro electrochemical machining (ECM) using the electrostatic induction feeding method. In ECM, electrolytic dissolution can be localized in the area where the gap width is narrow by using pulse durations shorter than several tens of nano-seconds. With the electrostatic induction feeding method which has been developed for micro electrical discharge machining, the current pulse of such short durations can be obtained more easily compared with the conventional pulse generators. In this study, the influences of the pulse voltage of power supply and feeding capacitance on the machining current were investigated theoretically. It was found that the current pulse duration is nearly equal to the rise time and fall time regardless of the pulse-on time of the pulse voltage. Hence, ultra-short pulses can be obtained without a need to use an expensive pulse generator. Micro-hole drilling carried out in a sodium nitrate aqueous solution with current pulse duration of 30ns showed that significantly small side gap of 2μm could be obtained.

Abstract: Micro-variable Radiator with its small volume, light weight and less power consumption quite meets the requirement of Micro/Nano satellite thermal control. Prototypes fabricated by bulk silicon technology have poor thermal performance owing to their confines of material and process. In this paper, a novel micro-radiator based on laser micro processing technology and polymer material was proposed, its operational principle was introduced and the relationship between structural and thermal performance was analyzed theoretically. A prototype was fabricated by UV laser micro-processing, dip-coating and magnetron sputtering technologies. Test results show that the actuation voltage is 97V and variation of radiation power is about 0.1W.