Dielectric ceramic composition and multilayer ceramic electronic component having the same

A multilayer ceramic electronic component comprising:

• a ceramic body including a dielectric layer and an internal electrode;
• and
• an external electrode disposed on an external surface of the ceramic body and electrically connected to the internal electrode,
• wherein a microstructure of the dielectric layer includes a first grain having a Ca content of less than 3.5 at % and a second grain having a Ca content of 3.5 to 13.5 at %,
• wherein an area ratio of the second grain to an area of a sum of the first and second grains is 70% to 95%,
• wherein the dielectric layer comprises a dielectric ceramic composition comprising a base material main component of barium titanate and a subcomponent,
• wherein the base material main component includes a first base material main component represented by (Ba1−xCax)TiO3 (x≤0.035) and a second base material main component represented by (Ba1−yCay)TiO3 (0.035≤y≤0.135), and
• wherein a molar ratio of the first base material main component to the second base material main component is (−z):z, in which 0.9≤z≤0.95.

A dielectric ceramic composition comprising:

• a base material main component of barium titanate and a subcomponent,
• wherein a microstructure of the dielectric ceramic composition after sintering includes a first grain having a Ca content of less than 3.5 at % and a second grain having a Ca content of 3.5 to 13.5 at %,
• wherein an area ratio of the second grain to an area of a sum of the first and second grains is 70% to 95%,
• wherein the base material main component excludes CaZrO3 and comprises a first base material main component represented by (Ba1−xCax)TiO3 (x≤0.035) and a second base material main component represented by (Ba1−yCay)TiO3 (0.035≤y≤0.135), and
• wherein a molar ratio of the first base material main component to the second base material main component is (1−z):z, in which 0.7≤z≤0.95.

A multilayer ceramic electronic component comprising:

• a ceramic body including a dielectric layer and an internal electrode;
• and
• an external electrode disposed on an external surface of the ceramic body and electrically connected to the internal electrode,
• wherein a microstructure of the dielectric layer includes a first grain having a Ca content of less than 3.5 at % and a second grain having a Ca content of 3.5 to 13.5 at %,
• wherein an area ratio of the second grain to an area of a sum of the first and second grains is 70% to 95%,
• wherein the dielectric layer comprises a dielectric ceramic composition comprising a base material main component of barium titanate and a subcomponent,
• wherein the base material main component excludes CaZrO3 and includes a first base material main component represented by (Ba1−xCax)TiO3 (x≤0.035) and a second base material main component represented by (Ba1−yCay)TiO3 (0.035≤y≤0.135), and
• wherein a molar ratio of the first base material main component to the second base material main component is (1−z):z, in which 0.7≤z≤0.95.