MULTIFUNCTIONAL VALVE COMPONENTS FABRICATED BY COMBINATION OF LIGA PROCESSES AND HIGH-PRECISION MECHANICAL-ENGINEERING

The advantage of thermoplastic molding as a convenient method for fabr icating large quantities of microstructures is restricted by the possi bilities and the necessary efforts for structuring the required moldin g tools. In order to increase the complexity of mold inserts without s ignificantly increasing the fabrication expenditure a new process comb ining LIGA techniques and precision mechanics had been suggested by Re search Center Karlsruhe. Recent work on the optimization of this proce ss made it possible to manufacture multi-leveled mold inserts with whi ch 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 embos sing in PMMA as well as in polymers with high thermal resistance and t he application in a microvalve system.