Use of Polyalkylene Carbonate Binders for Improved Performance in Multilayer Ceramic Capacitors

摘要

Past work by Polotai and co-workers produced convincing evidence that a Ni-Ba-Ti alloylayer forms at the electrode/dielectric interface of multilayer ceramic capacitors (MLCC’s) made with Nielectrodes and a barium titanate based dielectric. It has been shown that this alloy layer can lead todiscontinuous electrodes, resulting in reduced capacitance and lower reliability. The most likely explanationis that the alloy layer results from residual carbon remaining after the binders used to make the tape andpaste are decomposed. Polypropylene carbonate binder is known for its extremely clean burnout propertiesso a multilayer structure was prepared from QPAC? polypropylene carbonate binder in both the dielectrictape and nickel electrode paste. This was compared against a multilayer structure prepared using PVBbinder for the dielectric tape and a nickel paste based on ethyl cellulose. Examination of the fired parts byTEM clearly showed the elimination of the interfacial layer when using the polypropylene carbonate bindersystem. Good electrode continuity was also obtained.