Multilayer ceramic electronic component including external electrodes with multilayer structure

A multilayer ceramic electronic component comprising:

• a multilayer body including a plurality of stacked ceramic layers and a plurality of internal electrode layers, and including a first major surface and a second major surface opposite to each other in a height direction, a first side surface and a second side surface opposite to each other in a width direction orthogonal or substantially orthogonal to the height direction, and a third side surface and a fourth side surface opposite to each other in a length direction orthogonal or substantially orthogonal to the height direction and the width direction;
• and
• a plurality of external electrodes on the side surfaces of the multilayer body;
• wherein
• the plurality of internal electrode layers include a plurality of first internal electrode layers and a plurality of second internal electrode layers, with the first and second internal electrode layers alternately stacked with the ceramic layer interposed therebetween;
• the first internal electrode layer includes a first lead electrode portion extending to one of the first, second, third and fourth side surfaces, and a second lead electrode portion extending to one side surface other than the side surface to which the first lead electrode portion extends;
• the second internal electrode layer include a third lead electrode portion extending to one of the first, second, third and fourth side surfaces, and a fourth lead electrode portion extending to one side surface other than the side surface to which the third lead electrode portion extends;
• the plurality of external electrodes include a first external electrode connected to the first lead electrode portion, a second external electrode connected to the second lead electrode portion, a third external electrode connected to the third lead electrode portion, and a fourth external electrode connected to the fourth lead electrode portion;
• the first, second, third and fourth external electrodes include an underlying electrode layer, a lower plating layer on the underlying electrode layer at the third side surface and the fourth side surface, and an upper plating layer on the lower plating layer;
• the underlying electrode layer includes a thin film electrode including at least one selected from Ni, Cr, Cu, and Ti;
• at least a portion of the lower plating layer is connected to corresponding ones of the plurality of internal electrode layers;
• the lower plating layer is a Cu plating layer;
• the lower plating layer includes a lower layer region located closer to the multilayer body and an upper layer region located between the lower layer region and the upper plating layer;
• and
• the Cu plating layer in the lower layer region has a metal grain diameter smaller than that of the Cu plating layer located in the upper layer region.