Monolithic ceramic electronic component and method for manufacturing monolithic ceramic electronic component
A monolithic ceramic component includes a coil-including region formed by stacking ceramic green sheets for defining inner layers having a porosity of about 30% to about 80%, and outer layer regions formed by stacking ceramic green sheets for defining outer layers have a porosity of about 10% or less. Outer electrodes are provided on the right end surface and the left end surface of a sintered ceramic laminate. That is, the outer electrodes are provided on the main surfaces of outermost ceramic sheets for outer layers.
1. A monolithic ceramic electronic component comprising:
a ceramic laminate including a plurality of ceramic layers and a plurality of inner electrodes; and
outer electrodes, each of the outer electrodes being provided on a corresponding main surface of an outermost ceramic layer of the ceramic laminate, the plurality of ceramic layers having pores, a porosity of at least the outermost ceramic layers of the ceramic laminate being lower than that of the other ceramic layers.
2. The monolithic ceramic electronic component according to claim 1 , wherein the outermost ceramic layers of the ceramic laminate have a porosity of about 10 percent by volume or less.
3. The monolithic ceramic electronic component according to claim 1 , wherein a stacking direction of the plurality of ceramic layers in the ceramic laminate is substantially parallel to a mounting surface of the monolithic ceramic electronic component.
4. The monolithic ceramic electronic component according to claim 1 , wherein the ceramic layers are made from a Ni—Zn—Cu based ferrite material having an average particle size of about 2 μm.
5. The monolithic ceramic electronic component according to claim 1 , wherein the outermost ceramic layers of the ceramic laminate include a pore-forming agent.
6. The monolithic ceramic electronic component according to claim 5 , wherein the pore forming agent is made of cross-linked polystyrene having an average particle size of about 8 μm.
7. The monolithic ceramic electronic component according to claim 1 , wherein the ceramic laminate includes a coil-including region including a plurality of pores having an average diameter of about 5 μm to about 20 μm.
8. The monolithic ceramic electronic component according to claim 7 , wherein the coil-including region has a porosity of about 30% to about 80%.
9. The monolithic ceramic electronic component according to claim 1 , wherein the ceramic laminate is covered by an epoxy-based resin having a dielectric constant of about 3.4 except at locations of the outer electrodes.
10. The monolithic ceramic electronic component according to claim 1 , wherein the monolithic ceramic electronic component is one of an impedance component, an LC filter, a capacitor, a monolithic transformer, and a monolithic inductor.
11. The monolithic ceramic electronic component according to claim 1 , wherein the plurality of ceramic layers are made from at least one of a magnetic ceramic material, a dielectric ceramic material, a semiconductive ceramic material, and a piezoelectric ceramic material.
12. A method for manufacturing a monolithic ceramic electronic component, comprising the steps of:
preparing first ceramic sheets for defining outer layers, each of the first ceramic sheets including a ceramic material and a binder;
preparing second ceramic sheets for defining inner layers, each of the second ceramic sheets including a ceramic material, a binder, and a pore-forming agent;
forming inner electrodes, each of the inner electrodes being formed on a surface of a corresponding one of the second ceramic sheets;
forming a ceramic laminate by stacking the first ceramic sheets and the second ceramic sheets; and
forming outer electrodes, each of the outer electrodes being formed on a corresponding outer surface of the outermost ceramic sheet of the ceramic laminate.
13. The method according to claim 12 , wherein the step of preparing the first ceramic sheets includes preparing a Ni—Zn—Cu based ferrite material having an average particle size of about 2 μm, mixing the ferrite material, a solvent, the binder and a dispersant to a slurry, and using a doctor blade to form the slurry into the first ceramic sheets.
14. The method according to claim 12 , wherein the step of preparing the second ceramic sheets includes preparing a Ni—Zn—Cu based ferrite material having an average particle size of about 2 μm, mixing the ferrite material, the pore-forming agent, a solvent, the binder and a dispersant to a slurry, and using a doctor blade to form the slurry into the second ceramic sheets.
15. The method according to claim 12 , wherein the pore-forming agent is a spherical pore-forming agent made of cross-linked polystyrene having an average particle size of about 8 μm.
16. The method according to claim 12 , wherein the first ceramic sheets defining the outer layers have a porosity of about 10 percent by volume or less.
17. The method according to claim 12 , wherein a stacking direction of the plurality of ceramic layers in the ceramic laminate is substantially parallel to a mounting surface of the monolithic ceramic electronic component.
18. The method according to claim 12 , wherein the ceramic laminate includes a coil-including region including a plurality of pores having an average diameter of about 5 μm to about 20 μm.
19. The method according to claim 18 , wherein the coil-including region has a porosity of about 30% to about 80%.
20. The method according to claim 12 , further comprising the step of covering the ceramic laminate by an epoxy-based resin having a dielectric constant of about 3.4 except at locations of the outer electrodes.
21. The method according to claim 12 , wherein the monolithic ceramic electronic component is one of an impedance component, an LC filter, a capacitor, a monolithic transformer, and a monolithic inductor.
22. The method according to claim 12 , wherein the first and second ceramic layers are made from at least one of a magnetic ceramic material, a dielectric ceramic material, a semiconductive ceramic material, and a piezoelectric ceramic material.