Developing a Co-Sintered Copper-Ceramic Feedstock for Thermal Applications Using Fused Filament Fabrication

Conference Abstract: The demand for advanced materials in additive manufacturing has driven a need from traditional basic metals and ceramics towards more advanced high-performance materials and material combinations. A key challenge in device manufacturing stems from thermal flux, and thermal expansion mismatches. To overcome this, we propose that alumina ceramics and copper packaging are advantageous to better provide both thermal flux, and reduce thermal mismatch increasing device lifetime. Here, we report on the development and optimization of processing and sintering conditions for a feedstock for both a low temperature co-fired alumina ceramic (LTCC) and copper.
Here, we present our work on using LTCC and copper with fused filament fabrication (FFF) for a co-sintering process. We studied how inorganic additives influenced the sintering temperature of the LTCC allowing it be sintered at a copper compatible temperature. We studied the influence on polymer composition, and material loading for feedstock extrusion, 3D patterning, and solvent debinding. Furthermore, we studied the influence on the 3D patterning with mechanical properties, and the influence of an inert vacuum vs air atmosphere on the final part.
To characterize our results, we used thermogravimetric analysis, 3-D scanning, scanning electron microscopy, cross-section analysis, x-ray diffraction, and tensile testing. Through process optimization in printing, debinding, and sintering, we achieved densities of >95% of theoretical LTCC and sintering temperatures of 1000-1100°C without post-processing. The results of this research contribute to diversifying material selection for FFF and open new possibilities for utilizing LTCC and copper based 3D-printed components in technologically advanced application areas.