Fabrication of Microstructures of Extreme Structural Heights by Reaction Injection Molding
-
P. Hagmann
Abstract
For the fabrication of microstructures with minimum lateral dimensions in the micrometer range and structural heights of up to several hundred micrometers a new microfabrication technique has been developed by the Karlsruhe Nuclear Research Center. The so-called LIGA method is based on a combination of deep-etch X-ray-lithography, electroforming and plastic molding. High-quality micromold inserts can be prepared by deep-etch X-ray lithography and electroforming allowing an arbitrary choice of cross section of the microstructures. By optimization of the process parameters of the reaction injection molding process using casting resins on a methyl methacrylate base it has been shown that a yield of 100% can be achieved. For molding microstructures without any flaws, the mold material has to be degassed, the cavity of the mold must be evacuated and the shrinkage due to polymerization has to be compensated by applying a holding pressure. With an internal mold release agent which is a special salt of an organic acid, cycle times of about 12 min have been achieved in the micromolding process step which are very much shorter than the exposure and development times in the direct lithographic production of microstructures. Such plastic structures can represent the final product or, if microstructures are to be made of metal, they are used as templates in a subsequent electroforming process. Depending on the geometrical configuration of the microstructures, either a metallic gate plate or an electrically conducting plastic layer are used as the electrode for electroforming.
© 1989, Carl Hanser Verlag, Munich
Articles in the same Issue
- Contents
- Contents
- Original Contributions
- Prediction of Birefringence for Optical Memory Disk
- Transient Compressible Flow in Injection Molding Runner**
- Advances in Rheological Analysis of Injection Molding
- Optical and Mechanical Measurements to Characterize Injection Molded Polypropylene Plates
- Experimental Investigation of Rotational Molding and the Characterization of Rotationally Molded Polyethylene-Parts
- Blow Molding of Thermotropic Liquid Crystalline Polymers
- Position of Neutral Surface during Hollow Disk Compression Molding of Long Fibre-Reinforced Thermoplastics**
- Reactive Ion Etching of Polymer Films
- Fabrication of Microstructures of Extreme Structural Heights by Reaction Injection Molding
- Rheological Properties of Glass Fiber Filled Nylon 6 Composite System
Articles in the same Issue
- Contents
- Contents
- Original Contributions
- Prediction of Birefringence for Optical Memory Disk
- Transient Compressible Flow in Injection Molding Runner**
- Advances in Rheological Analysis of Injection Molding
- Optical and Mechanical Measurements to Characterize Injection Molded Polypropylene Plates
- Experimental Investigation of Rotational Molding and the Characterization of Rotationally Molded Polyethylene-Parts
- Blow Molding of Thermotropic Liquid Crystalline Polymers
- Position of Neutral Surface during Hollow Disk Compression Molding of Long Fibre-Reinforced Thermoplastics**
- Reactive Ion Etching of Polymer Films
- Fabrication of Microstructures of Extreme Structural Heights by Reaction Injection Molding
- Rheological Properties of Glass Fiber Filled Nylon 6 Composite System
