Isothermes Heißprägen von beschichteten Glaswafern
ABSTRACT Hot-embossing is an economical manufacturing process for the structuring of glass. For structures with dimensions in the millimetre and micrometre range and high aspect ratios it is necessary to work under isothermal process conditions. In order to prevent the sticking of the glass to the tool, the glass substrates were coated with thin metal, carbon and oxide layers. The layers were examined with respect to their behaviour change and suitability for the embossing process. All layers showed a clear reduction of the adhesive forces and a shift of the sticking temperature to higher temperature ranges. Some layers led even to the abolition of any sticking in the entire viscosity range relevant for the hot-embossing of glass. The examined layers behave ductile with small strains, however, under larger elongations tend to cracking. Fluidic demonstration structures were realized and hot-embossed successfully in float glass. The lateral design geometries of the channels and chambers lay between 10 µm and 2 mm with embossing depths up to 2 mm. The largest aspect ratio of embossing depth to structural width amounted to 3. The attainable accuracies and surface qualities correspond thereby to that of the used mould insert. The results of the research show the extraordinary potential of the new coating strategy for the hot-embossing of glass.
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ABSTRACT: This paper reports the highest etch depth of annealed Pyrex glass achieved by wet etching in highly concentrated HF solution, using a low stress chromium–gold with assistance of photoresist as masking layer. The strategies to achieve that are: increasing the etch rate of glass and simultaneously increasing the resistance of Cr/Au mask in the etchant. By annealing the Pyrex glass and using a highly concentrated HF acid, a high etch rate can be obtained. Furthermore, a method to achieve a good resistance of the Cr/Au masking layer in the etching solution is to control the residual stress and to increase the thickness of Au deposition up to 1μm. In addition, the presence of a hard baked photoresist can improve the etching performance. As a result, a 500-μm thick Pyrex glass wafer was etched through.Microsystem Technologies 01/2006; 12(10):935-939. DOI:10.1007/s00542-006-0116-0 · 0.95 Impact Factor
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ABSTRACT: We present a novel approach for the realization of complex three-dimensional microstructures in brittle materials, like glass. Our technology is based on a beam of eroding powder particles, etching a masked rotating substrate. By using an oblique powder beam and mask under-etching effects, we fabricate monolithic millimeter-high microstructures with an aspect ratio of 5 to 10. This intrinsically very simple microfabrication method also allows to realize in a unique way free-standing monolithic glass microstructures, suspended over many millimeters.Journal of Microelectromechanical Systems 11/2002; 11(5-11):521 - 527. DOI:10.1109/JMEMS.2002.803418 · 1.92 Impact Factor
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ABSTRACT: We present a novel process technology, which enables precision micro machining of glass wafers. With this Glass Flow Process GFP which is based on viscous deformation at temperatures above the glass transition temperature T<sub>g</sub>, any surface topography available on a silicon substrate can be moulded into Borosilicate glasses, especially into bondable glasses like Borofloat or Pyrex. Beside the replication of silicon structures this technique allows the fabrication of optical micro lens arrays with high aspect ratios and minimum spacing. Introducing this GFP technology to MEMS processing enables the deep structuring of glass substrates and opens a wide range of new applications. Optical quality micro lenses with saggital heights above 100 μm are demonstrated. In this paper an insight description of the GFP technology is given and the functionality of this new technology is presented by optical measurements of micro lens demonstrators.TRANSDUCERS, Solid-State Sensors, Actuators and Microsystems, 12th International Conference on, 2003; 07/2003