Here is the abstract you requested from the IMAPS_2011 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Packaging Technology of Multi Deflection Arrays for Multi-Shaped Beam Lithography|
|Keywords: multi shaped beam lithography, MEMS assembly, laser-based soldering|
|Multi-Shaped Electron Beam Lithography is considered to be a promising approach for mask and direct writing. Providing multiple apertures and individually controlled electrodes allow for massive parallelization of exposure shots, thus significantly decreasing write time and leading to high throughput processing. A novel 64 beamlets design of a silicon-based micro-structured MEMS Multi Deflection Arrays (MDA) and necessary alignment and fixation procedures are presented. High operating temperatures and application under vacuum conditions in the electron beam column are prohibitive to the use of organic polymers due to possible outgassing and with respect to long term stability. A laser-based joining technology, Solderjet Bumping is used to provide mechanical fixation and electrical interconnection by means of adhesive free, metal-based solder joints. Solderjet Bumping provides a flux-free and contact free soldering process with minimized input of thermal energy allowing for the joining of fragile and sensitive materials. Solder sphere diameters of down to 80 µm allow for a significant decrease in solder joint size and pitch, thus enabling for complex circuitry. The hybrid integration of MDA devices in ceramic system carriers made of LTCC (Low Temperature Cofired Ceramics) or alumina featuring miniaturized solder joints made of eutectic Gold-Tin solder alloy are demonstrated. Electron beam deflection in two perpendicular directions requires the highly accurate placement of two crossed MDA devices, which is carried out by three DOF alignment procedures and solder joining. This precision adjustment of two carriers is accomplished by fiducial mark detecting using image processing. Results on alignment accuracy in the sub-micron range and thermo-mechanical behaviour of such assemblies are reported. Aperture overlay accuracy is investigated using electron beam equipment.|
Fraunhofer Institute for Applied Optics and Precision Engineering
Jena, Thuringia 07745,