Evaluation of residual stress in BaTiO3-based Ni-MLCCs with X7R characteristics

The residual stress in BaTiO3-based multilayer ceramic capacitors (MLCCs) with X7R characteristics was estimated at three different margins using a micro-indentation technique. The hardness at the margins of the MLCCs was in the range 8-13.1 GPa, depending on the direction at each margin, and the hardness decreased with increasing distance from the electrode. At the l and w margins parallel to the electrode, the residual stresses were indicative of compressive stresses of - 45 +/- 8 MPa and - 2.7 +/- 18 MPa in the direction parallel to the electrode, and tensile stresses of 177 +/- 71 MPa and 281 +/- 177 MPa in the direction perpendicular to the electrode, respectively. Moreover, the other t margin perpendicular to the electrode showed the reverse tendency in the residual stresses, with tensile and compressive stresses of 118 +/- 113 MPa and - 54 +/- 11 MPa in the directions parallel and perpendicular to the electrode, respectively. The residual stresses created on the MLCCs depended on the margin with the lamination and on the direction to the electrode. (C) 2004 Kluwer Academic Publishers.