By means of experiments it could determined that micro-machining processes as grinding, drilling and milling are a good addition to the established production technologies in micro technology. To machine hard and brittle materials grinding with diamond tools is well suitable, but the kinematics of the grinding process, as well as the process strategy has a significant influence on the machined surface quality and the chipping of the edges. The study of micro-machining processes showed, that micro cutting processes are not just a miniaturisation of the conventional cutting technology. The reduced tool stiffness of micro drills caused by the changes of geometry requires an adjustment of the complete drilling processes. Sharp cutting edges are an essential requirement for the fabrication of very small structures. So, using single edged micro milling cutters made of diamond significant smaller structures could be made compared to using conventional milling cutters made of tungsten carbide. Furthermore, acoustic emission sensors proved to be suitable for detecting the tool position after a change of the tool with a high accuracy.

As a suitable mass and cost efficiency fabrication method, micro injection molding is doing a very good performance in micro plastic parts production. The mold design is an important part affecting micro parts properties. In this study, a micro injection mold with multi cavities of micro tensile bar is used. These micro cavities are fabricated by a micro milling process in different cross section shapes (semicircle R = 0.5 mm, equilateral triangle D = 0.3 mm, and trapezoid D = 0.336 mm t = 0.2 mm bottom angle = 95°). With an Arburg Ò 320C injection molding machine, micro tensile test sample are prepared in different processing parameters so that a correlation between the cross section shapes with micro weld line strength in different conditions could be investigated by tensile test. Final results show that when the cross section shape is different, their corresponding weld line strength is also different. Equilateral triangle cross section is leading to strongest weld line, and then followed by trapezoid, semi-circle is the last. By analysis of these tensile test results, the quantitative factor a is defined as the ratio of perimeter to area of cross section shape, and higher a value is corresponding stronger weld line. After weld line strength comparison in different processing conditions, the results show that higher injection pressure induced to lower weld line strength whatever the cross section shape is. By higher mold and melt temperature, equilateral triangle cross section gives improved weld line strength. But mold and melt temperature affect weld line strength negative for other cross section shapes.

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An increasing trend towards miniaturization of mechanical components necessitates the further development of micro-machining techniques in order to produce components within given tolerances. For the dressing of multilayered, metallically bonded, fine-grained grinding wheels that are used for micro-grinding the technique of electro contact discharge dressing was developed. In the following, the determined interrelations between the variables dressing voltage, limitation of dressing current, infeed and feed of electrode, and the volume flow rate in conditioning as well as the quality factor in conditioning are presented and illustrated. Thanks to the development of new geometries of CVD-diamond micro-grinding-pencils, a reduction of edge disruptions as well as a reduction of tool diameters to a minimum of 250 lm for the machining of brittle materials could be achieved. For the micro-drilling of ductile materials the maximal drilling depth could be increased by means of an adjusted process control. The smallest examined drill diameter was 50 lm. The utilizability of the developed processes and tools was proven in the production of aerostatic micro-bearings in the scope of the collaborative research center (SFB) 516.

Microgrinding wheels are suitable for the microstructuring of hard and brittle materials but usually they can only manufacture structures with rectangular geometries because of their limited profile geometries. The use of microgrinding wheels with a special profile is uncommon. This is due to the fact that microgrinding wheels with a profile are difficult to manufacture; furthermore, the renewing process after the profile has worn is difficult to accomplish. A new and successful approach is to true the microgrinding wheels by miniaturized diamond profile rollers. The technology of trueing grinding wheels by diamond profile rollers is highly favored and well established in macroscopic grinding technology. Easy kinematics, high quality, and short processing times make this technology very efficient. Moreover, this technology allows for a periodical renewing of the profile inside the grinding machine. Confirmed by those technological advantages, the authors developed diamond tools in order to realize a truing process for microgrinding wheels.