Zeitschriftenaufsätze und Buchbeiträge

Stainless steel films were reactively magnetron sputtered in argon/methane gas flow onto oxidized silicon wafers using austenitic stainless-steel targets. The deposited films of about 200 nm thickness were characterized by conversion electron Mössbauer spectroscopy, magnetooptical Kerr-effect, X-ray diffraction, scanning electron microscopy, Rutherford backscattering spectrometry, atomic force microscopy, corrosion resistance tests, and Raman spectroscopy. These complementary methods were used for a detailed examination of the carburization effects in the sputtered stainless-steel films. The formation of an amorphous and soft ferromagnetic phase in a wide range of the processing parameters was found. Further, the influence of the substrate temperature and of post vacuum-annealing were examined to achieve a comprehensive understanding of the carburization process and phase formation.

Embossing of LTCC green tapes allows the defined patterning of conductor paths and fluidic channels with excellent edge moulding. However, basic process settings have not systematically been investigated up to now. We present a comprehensive overview, regarding basic process variables and new manufacturing approaches. Because the moulding quality depends on the visco-elastic properties of the tape, rheological measurements were carried out. The influence of the basic process parameters, that is, temperature, pressure, time and friction were investigated systematically under the use of design of experiments. The influence of these parameters on the forming of micro patterns down to 10 ?m was investigated, as also where the stress of the tape caused by the plastic deformation, the accuracy of edge moulding and the demoulding behaviour of embossed tape. Optimum parameters were derived. From Analysis of Variances it is clear that the friction exerts the most important influence on the moulding of fine patterns. Position tolerances of embossed patterns were determined and relaxation effects studied in order to ensure stable process conditions. It was possible to improve the leakage characteristics of valve seats by making use of embossed patterns like smoothed metallization and 3-dimensional sealing ring. The leakage characteristic of valve seats could be improved by the factor of four.