Process Development for Realization of Embedded Structures in Multi-Layer Ceramics Platform using Carbon Fugitive Material

Fabrication of embedded structures in a multi-layer low co-fired ceramic (LTCC) substrate is essential in realizing multi-functional platform. One of the major fabrication challenges is to preserve the designed dimensions of the embedded structures and to minimise distortion due to high lamination pressure and viscous flow of glass component during sintering. Fabrication techniques by employing fugitive material such as carbon could minimise distortion. Carbon powder could be formulated as paste or tape for incorporation by filling or drop-in respectively into the LTCC process to secure the fragile structure during the lamination and later the sintering process. Carbon could be completely burnt off under oxidizing environment and without any residue. This paper presents the current progress in developing a fabricaton process of realizing embedded structures in multi-Layer LTCC platform using carbon material as a supporting medium for the structures. To ensure complete carbon burnout from the LTCC platform containing embedded structures, the carbon burnout kinetic are determined by, thermogravimetry. The dependency of activation energy (Eiquest) over the extent of conversion is solved by, non-linear isoconversional methods. The activation energy is found to be high at the starting of the reaction, and has a gradual decreasing trend from 143.3 kJ/mol to 106.5 kJ/mol over a conversion of 0.1 to 0.9. The analysis of activation energy is also used to predict the carbon bum-off kinetic at isothermal condition for the development of multi-step sintering for embedded structure fabrication.