Comparison of solvent and sacrificial volume-material-based lamination processes of low-temperature co-fired ceramics tapes

Abstract

The lamination process determines the quality of low temperature co-fired ceramics (LTCC) based spatial structures. This paper compares two methods of the microchannel fabrication process in zero-shrinkage LTCC substrates. The first one is based on a two-step lamination process and uses various sacrificial volume materials (SVM). The second one is based on the cold chemical lamination (CCL) process. On the one hand, the SVM gives the possibility of decreasing the deformation of the three-dimensional (3D) structures during the lamination process. The channel volume is filled with a special fugitive material. It protects the spatial structure from deformation during lamination, and evaporates completely during the co-firing process. The bonding quality and strength depend strongly on the fugitive phase type. On the other hand, the CCL is a solvent-based method. It is another alternative for bonding of green ceramic tapes. A special liquid agent is screen printed on the green tape, which melts the tape surface. Then the tapes are stacked and compressed at room temperature by a printing roll. The influence of each method on the microchannel geometry is analyzed in this paper. The resulting structures' bonding quality and mechanical properties are examined by a scanning electron microscope (SEM).