Structuration of micro-fluidic devices based on low temperature co-fired ceramic (LTCC) technology

Smart packaging concept has been the driving force for the search of advanced technologies to produce multi-functional micro-scale devices for long years. In this sense, LTCC technology has been recently addressed as the suitable choice for a wide range of applications. In addition to its attractive characteristics for high-frequency applications those have been profited for a long time, it receives a growing attention for sensor applications in the recent years as well. This is due to the easy machinability of the LTCC tapes, which permits realization of complex structures such as membranes, channels, making it a suitable environment for micro-fluidic devices. These devices require utilization of supporting layers in order to prevent defects, often observed in forms of sagging, warpage or curling. The methods for elimination of these defects vary from passive precautions taken during lamination and firing to more elaborate methods such as use of sacrificial layers. The basic idea in the latter method is the preparation of a support, which can then be removed, leaving behind the desired structure. Among a number of alternatives, this paper focuses on and proposes the carbon-black sacrificial paste as an effective and simple method to fabricate membranes. Additionally determination of the open porosity elimination temperature in LTCC and effect of processing parameters on the fabricated structures, will be discussed. The methods of analysis will be TGA (thermo gravimetric analysis), dilatometer and SEM (scanning electron microscopy) analysis.