Multilayer ceramic capacitor including dielectric layers having improved reliability

A multilayer ceramic capacitor comprising:

• a ceramic body including dielectric layers and first internal electrodes and second internal electrodes disposed to face each other with one of the dielectric layers interposed therebetween;
• and
• first and second external electrodes disposed on external surfaces of the ceramic body and electrically connected to the first and second internal electrodes, respectively,
• wherein the dielectric layers include a dielectric composition including:
• a base material powder,
• a first accessory component containing an oxide or a carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu or Zn, the first accessory component having a content of 0.05 to 2.0 mol % based on 100 mol % of the base material powder,
• a second accessory component containing an oxide or a carbonate containing Mg, the second accessory component having a content of 0.0 to 2.0 mol % based on 100 mol % of the base material powder,
• a third accessory component containing an oxide or a carbonate containing at least one of Y, Dy, Ho, Er, Gd, Ce, Nd, Pm, Eu, Tb, Tm, Yb, Lu or Sm, the third accessory component having a content of 0.0 to 4.0 mol % based on 100 mol % of the base material powder,
• a fourth accessory component containing an oxide or a carbonate containing Ba, the fourth accessory component having a content of 0.0 to 4.15 mol % based on 100 mol % of the base material powder,
• a fifth accessory component containing an oxide or a carbonate containing at least one of Ca or Zr, the fifth accessory component having a content of 0.0 to 20.0 mol % based on 100 mol % of the base material powder, and
• a sixth accessory component containing an oxide containing at least one of Si or Al, or a glass compound containing Si, the sixth accessory component having a content of 0.0 to 4.0 mol % based on 100 mol % of the base material powder,
• the dielectric layer includes dielectric grains, a grain boundary is present between at least two dielectric grains of the dielectric grains,
• a Si/Ti mole ratio in the grain boundary satisfies 15% to 40%, and
• the grain boundary has a thickness of 0.2 nm to 5 nm.