Hydrogen migration in BaTiO3-based dielectrics under high humidity and electric field bias

This study investigates the possibility of hydrogen migration in BaTiO3-based dielectrics to improve the electrical reliability of multi-layer ceramic capacitors under conditions of high temperature, humidity, and electric field bias. It was observed that the deuterium in the dielectric drifted and migrated with the electric field, suggesting that deuterium exists as D+. The activation energy was found to be 0.34 eV, which is lower than that observed in previous studies. This finding offers a better understanding of the mechanism behind the migration of deuterium in a dielectric, which is highly relevant to future research in dielectrics and electronic components.

Mixed Solvents in Multi-Layer Ceramic Capacitors (MLCC) Elec-Tronic Paste and Their Effects on the Properties of Organic Vehicle

The copper end paste used in multilayer ceramic capacitors sintered in nitrogen atmosphere will lead to carbon residue of organic vehicle, which will lead to the reduction of electrode conduc-tivity and high scrap rate. With an attempt to leave no residue in the sintering, the compatibility of solvents and thickeners should be improved because it has an important influence on the hi-erarchical volatilization and carbon residue of organic vehicles. In this work, the volatility of different solvents was compared and several solvents were mixed in a definite proportion to prepare an organic vehicle with polyacrylate resins. The hierarchical volatility and solubility parameters of mixed solvents were adjusted effectively by changing proportions of different components, the thermogravimetric curves of resins and organic vehicles were measured by thermogravimetric analyzer, the effect of solubility parameter on the dissolvability of resins in the solvent and the residual of organic vehicles were studied. Results showed that the hierar-chical volatilization of solvents can be obtained by mixing different solvents; the intrinsic vis-cosity of the organic vehicle is higher and the thermal decomposition residue of polyacrylate resins is lower when the solubility parameters of mixed solvents and polyacrylate resins are closer. The low residual sintering of organic vehicles can be achieved by using the mixed solvent with hierarchical volatility and approximate solubility parameters as resins.

Investigation of an embedded closed-loop stimulation current control principle based on the use of nonlinear ceramic capacitors

Over the years, a constant progress in the development of implantable medical devices (IMD’s) can be observed. On one hand, the advanced implantable electronics enable the implementation of numerous smart functionalities, on the other hand, the variety of electronic components including sensors and a bulky battery severely restrict their degree of miniaturization and reliability. To overcome this limitation, our approach is to realize smart functionalities in leadless and battery-free IMD’s emerging from frugal innovation by exploiting the intrinsic nonlinear properties of the components to be used anyway. The aim of this work is to deepen the understanding of the dynamic behavior of circuit topologies of nonlinear ferroelectric ceramic capacitors and to investigate their potential use for an embedded closed-loop control of the stimulation current. We characterized a selection of 40 commercial ceramic capacitors by measurement and simulation. The degree of nonlinearity resulting from a circuit topology consisting of one, two series and two parallel connected nonlinear capacitors was modeled and evaluated in Mathcad. We present a model with parameterized nonlinear capacitors to simulate the dynamic behavior of an inductively coupled implantable system. The stabilization and amplitude of the stimulation current is controlled by two features. These features are in turn controlled by the circuit topology and the degree of nonlinearity of the capacitors. We found that a high degree of nonlinearity allows the stimulation current to be stabilized within a reasonable range, but it makes the system more prone to instability. However, our model needs to include the dynamic behavior of ferroelectric materials used as dielectric in ceramic capacitors to extend the current investigations and to deepen the understanding of the physics behind the nonlinear properties of ferroelectric capacitors.