Defect Free Lamination of Low Temperature Co-Fired Ceramic Multi-Chip-Modules

In Low Temperature Co-Fired Ceramic (LTCC) technology, lamination of green ceramic tapes is one of the most pivotal steps. Lamination process, if not properly optimized, can affect the final strength as well as integrity of three-dimensional (3-D) structures and printed patterns in LTCC. In this work, we have conducted lamination experiments using Ferro A6M-E LTCC tapes and addressed several challenges. Optimization of lamination process parameters was done with the help of Design of Experiments (DOE) to arrive at a lamination density of 1.80 gms/cm
³
, sintered density of 2.5 gms/cm
³
and post fired flexural strength of 177 MPa. The effect of lamination pressure on density and shrinkage is studied. Prevention of cavity distortion is proposed through precise design and use of silicone-based inserts. Occurrence of conductor pattern cracks accruing from the use of silicone inserts is eliminated through the use of Poly-Eutherene sheets. Inspection, post micro-sectioning of laminated tapes and 3-D X-ray microscopy were used for characterization at various experimental stages.