Crack suppression and residual stress in BaTiO3 based Ni-MLCCs of Y5V specification through post-process

Abstract

The effects of an additional processing using pressure and heat treatment, that is, a "post -process", on crack suppression and residual stress are investigated in BaTiO3-based multilayer ceramic capacitors (MLCCs) with Y5V characteristics. At the planes (margins) parallel to the electrode, the crack length is dramatically reduced after the post-process in the direction parallel to the electrode, without a change in the direction perpendicular to the electrode. At the plane perpendicular to the electrode, the crack length is modestly reduced in both parallel and perpendicular directions. The post-process is effective in reducing the difference in crack length between directions at each plane. The residual tensile stresses induced at the planes of the MLCCs before the post-process are converted to the compressive stresses and the residual compressive stresses are enhanced through the post-process. The MLCCs after the post-process show the residual compressive stress of approximately 300 MPa throughout entire planes. (c) 2007 Elsevier B.V. All rights reserved.