Multilayer ceramic capacitor

摘要

A multilayer ceramic capacitor includes a multilayer unit, thickness-direction first and second outer layer sections, and width-direction first and second outer layer sections. A dimension of the thickness-direction second outer layer section is greater than a dimension of the thickness-direction first outer layer section. The thickness-direction second outer layer section includes an inner portion and an outer portion. A composition ratio of Si to Ti in a ceramic dielectric layer included in the outer portion is higher than that in the inner portion. A Si content ratio is higher in a boundary portion between the outer portion and the inner portion. A thickness dimension of the multilayer unit is greater than a width dimension thereof, and width dimensions of the width-direction first and second outer layer sections are greater than a thickness dimension of the thickness-direction first outer layer section.

主权项

1. A multilayer ceramic capacitor comprising:
a body including conductive layers and ceramic dielectric layers alternately stacked on each other in a thickness direction; and a plurality of outer electrodes disposed on portions of the body; wherein the body includes first and second principal surfaces opposing each other in the thickness direction, first and second end surfaces opposing each other in a length direction, and first and second side surfaces opposing each other in a width direction; the plurality of outer electrodes includes a first outer electrode covering at least the first end surface and a second outer electrode covering at least the second end surface; some of the conductive layers include a first effective portion and a first extension portion extending from the first effective portion toward the first end surface and connecting to the first outer electrode, and others of the conductive layers include a second effective portion and a second extension portion extending from the second effective portion toward the second end surface and connecting to the second outer electrode; the body includes a multilayer unit including an effective portion defined by the first and second effective portions and portions of the ceramic dielectric layers stacked therebetween; the body is sectioned in the thickness direction into a thickness-direction first outer layer section that includes one of the ceramic dielectric layers defining the first principal surface, a thickness-direction second outer layer section that includes one of the ceramic dielectric layers defining the second principal surface, and a thickness-direction inner layer section that includes the multilayer unit and that is disposed between the thickness-direction first and second outer layer sections; the body is sectioned in a width direction into a width-direction first outer layer section that includes a portion between the first side surface and the multilayer unit, a width-direction second outer layer section that includes a portion between the second side surface and the multilayer unit, and a width-direction inner layer section that includes the multilayer unit and that is disposed between the width-direction first and second outer layer sections; a dimension of the thickness-direction second outer layer section in the thickness direction is greater than a dimension of the thickness-direction first outer layer section in the thickness direction; the ceramic dielectric layers included in the thickness-direction inner layer section and the thickness-direction first and second outer layer sections contains barium titanate and Si; the thickness-direction second outer layer section includes an outer portion which includes the second principal surface and an inner portion disposed between the thickness-direction inner layer section and the outer portion; a composition ratio of Si to Ti in one of the ceramic dielectric layers included in the outer portion is higher than a composition ratio of Si to Ti in one of the ceramic dielectric layers included in the inner portion; a boundary portion between the outer portion and the inner portion has a larger Si content than the outer portion; and both of a minimum dimension of the width-direction first outer layer section and a dimension of the width-direction second outer layer section in the width direction are greater than the dimension of the thickness-direction first outer layer section in the thickness direction.