Microscopic Analysis Of MLCC Cast Tape

With the change of the market structure of electronic product, MLCC（multilayer ceramic chip capacitor dielectric） have become increasingly demanding. At present, the development direction of MLCC is mainly small size, large capacity, high voltage and thin dielectric layer. The performance of MLCC cast film is the key to its development. In this paper,based on the SEM, SAM and XRD microcosmic analysis method, the MLCC cast film was analyzed, mainly involving with powders of BaTiO₃ crystal phase structure, sintering behavior and MLCC cast film, the specific contents are as follows:1) Microstructure and sintering properties of BaTiO₃ powders were analyzed by SEM and XRD respectively. First, BaTiO₃ powder specimens were prepared by oxalate co precipitation, Then the phase of BaTiO₃ powder prepared under different water temperature and different calcination temperatures were analyzed by XRD. The results show that the water bath temperature does not have an effect on the crystal structure, while the calcination temperature has a significant effect on the crystal structure. In the end, the SEM is used to analyze the crystal grain of pure BaTiO₃ sintered ceramics. The analysis results are as follows, the pre sintering temperature affects the grain size, and the sintering temperature has an effect on its compactness. An increase of the sintering temperature will lead to the grain size have the obvious difference.2) The position and morphology of the defects of MLCC products were established by SAM（ultrasonic scanning microscope）. The defect is in the horizontal direction of the interface between the ceramic membrane and the ceramic membrane, or the single layer ceramic film, which is characterized as the hole and the impurity. Different casting process has an effect on performance of MLCC solvent cast films, differences of casting process will lead to problems such as dispersion uniformity of film, holes, agglomeration. Due to the permeability of MLCC solvent cast films, the laminated process, temperature isostatic pressing and glue the follow-up process will influence of compactness of MLCC.3) The water-based tape casting experiment on 6 different groups, 6 groups of the viscosity of the slurry was measured by viscometer, the rheological properties of slurry were observed. After casting, to observe the relationship between the film thickness and the crack,and the relationship between the film thickness and Z axis shrinkage, Finally, the micro morphology of the film was analyzed by SEM. Draw the conclusion as follows, both of the 6 groups have shear thinning properties, with the increase of rotational speed, the viscosity of the slurry is gradually reduced, when the speed exceeds the speed of 40 rpm, with the increase of speed, the slope of the viscosity decreased to the same. Drying shrinkage rate changes with the film thickness,with the increase of the thickness of the film, its shrinkage gradually becomes larger and tends to be stable. The viscosity of the slurry with PVA is very large, liquidity is not good, but after adding acrylic emulsion, the fluidity of the slurry becomes better.Through the above work, recognize the importance of micro analysis with MLCC film, using the microscopic analysis method can better control its quality.