Multi-functional Valve components fabricated by combination of LIGA processes and high precision mechanical engineering

The advantage of thermoplastic molding as a convenient method for fabricating large quantities of microstructures is restricted by the possibilities and the necessary efforts for structuring the required molding tools. In order to increase the complexity of mold inserts without significantly increasing the fabrication expenditure a new process combining LIGA techniques and precision mechanics had been suggested by Research Center Karlsruhe. Recent work on the optimization of this process made it possible to manufacture multi-leveled mold inserts with which different three-dimensional microcomponents have successfully been molded. The two-and three-level structures feature among other details integrated alignment aids which worked very well during the assembly of the valve system the components were designed for. This paper deals with the process optimization, the manufacturing of the mold inserts, the fabrication of the three-dimensional microstructures by hot embossing in PMMA as well as in polymers with high thermal resistance and the application in a microvalve system.