Terminal electrod composition for multilayer ceramic capacitor

Abstract

The present invention relates to terminal electrode compositions for multilayer ceramic capacitors. More specifically, it relates to terminal electrode compositions for multilayer ceramic capacitors, which compositions are made of a conductive-based powder and a glass frit and can be fired at a low temperature in a nitrogen atmosphere.

Description

technical field [0001] This invention relates to terminal electrode thick film compositions for multilayer ceramic capacitors. In particular, the present invention relates to a terminal electrode composition for a multilayer ceramic capacitor (MLC), which comprises a conductive powder and a frit binder and can be sintered at a low temperature in a nitrogen atmosphere. technical background [0002] A conductive thick film paste composition comprising a matrix metal such as copper or nickel dispersed in an organic binder, an inorganic binder is widely used as a material for a terminal electrode of a multilayer ceramic capacitor. These conductive pastes are sintered in a neutral or reducing atmosphere to prevent oxidation of the metals they contain and the internal electrodes and thereby obtain a suitable terminal connection state. The inorganic binder used is mainly glass frit. The fluidity (softening performance) of the glass frit is the main factor affecting the sintering ...

AI Technical Summary

Problems solved by technology

[0003] However, conventional conductive compositions comprising lead silicate glass commonly used in the art, after drying to remove the organic binder, are sintered at temperatures below 800°C for a time sufficient to sinter the inorganic material to produce an adherent to the multilayer ceramic capacitor forming a conductive pattern on the position of the terminal electrode, there will be some problems

[0004] Insufficient fluidity of the glass in the electrode is not conducive to adhesion to the capacitor assembly, and even if the adhesion to the capacitor is good, the sintering of the terminal electrode is not sufficient to form a dense structure

Therefore, in the subsequent plating step, the plating solution penetrates through the terminal electrodes, causing the glass components to be corroded by the acid in the solution, seriously reducing the final strength

[0005] Select a glass frit with good fluidity or low softening point, and sinter the electrode at a temperature lower than 800°C to increase the density of the formed electrode, resulting in the glass starting before the conductor in the internal electrode and the conductor in the terminal electrode are alloyed. Flow, thus forming a thin dielectric layer between the internal electrode and the terminal electrode, which reduces the stability and reliability of its electrical properties

In addition, the composition contains a glassy inorganic binder with a lower glass softening point, which also increases the coefficient of thermal expansion, which will lead to cracks in the capacitor assembly or electrode due to the difference in coefficient of thermal expansion between the electrode and capacitor assembly , compromising electrical properties, adhesion and reliability