The project Micro-Stereolithography of the research network FORMIKROSYS II sets in here and wants to improve the lithography procedure in such a way in the next three years, that highly precise models can be produced reliably. To reach accuracy in the range of 0.01 mm, a new technique for layer-production and a better mapping for the laserbeam have to be developed. The MSL-machines will find a ready market in several branches of modern industry like medicines and electronics (miniature-jacks, housings for mobile telephones, etc).

At FORWISS Passau the software for data-editing and machine-control is developed.

The stereolithography process is based on the layerwise hardening of a photo-sensitive polymer with UV-laserradiation. The following process-chain has to be traversed:

1. Preparation of threedimensional CAD-data on the CAD-workstation
   • Placement of the CAD-objects in the workspace (s. Fig. right)
   • Slicing of the data
   • Generation of supporting structures
   
2. Data transfer to the controling-computer of the MicroSL-machine
3. Calculation of vectors representing the contours and hatches of the slices (s. Fig. below)
4. Recoating of a thin resin-layer
5. Selective exposure of the surface with the laser-scanner
6. Subsiding of the building platform
7. Repetition of the steps 4-6 until the the parts have been completed
8. Post-processing (finishing) of the stereolithography-model (posthardening, support removing)

• Markus Frohnmaier
• Alexander Welisch

• Alphaform Enabling Technologies and Services AG, Feldkirchen b. München
• Epoxonic GmbH, Landsham/Pliening b. München
• F&S Stereolithographietechnik, Paderborn
• PRIMACON Maschinenbau GmbH, Peissenberg b. München
• Siemens AG, München
• Technische Universität München, Lehrstuhl für Feingerätebau