Manufacture of 3D structures by cold low pressure lamination of ceramic green tapes

Abstract

3D multilayer devices were generated by Laminated Object Manufacturing (LOM), a well-known rapid-prototyping technology. Divergent from this method, commercial ceramic green tapes were used which were laminated by Cold Low Pressure Lamination (CLPL). In contrast to thermo-compression, which works at pressures and elevated temperatures, CLPL allows to join particularly fine, complex structures with cavities or undercuts, because no mass flow occurs. This technique is based on gluing the adjacent tapes by means of an adhesive film at room temperature under a low pressure. After binder burnout and sintering the ceramic laminate has a homogenous and dense microstructure free of interfaces. This modified LOM technique is particularly suitable for the production of Micro Electro Mechanical Systems (MEMS). In the given paper commercial Low Temperature Co-fired Ceramic (LTCC) green tapes were used, which were structured by means of a high-frequency milling plotter and laminated by using CLPL. Various 3D devices of different shape with inlying cavities were manufactured. The quality of the fired and unfired structures of the devices were characterised by different methods and show a high quality surface of the multilayer structures. Process aspects of the CLPL technique are discussed. The results demonstrate the advantages of this method for the fabrication of MEMS.