MULTILAYER CAPACITOR, MOUNTING STRUCTURE THEREOF, AND METHOD OF MANUFACTURING SAME

1 . A multilayer capacitor comprising:

a capacitor element body having first and second side faces, each having a substantially rectangular form, opposing each other, third and fourth side faces extending in a longer side direction of the first and second side faces so as to connect the first and second side faces to each other and opposing each other, and substantially square first and second end faces extending in a shorter side direction of the first and second side faces so as to connect the first and second side faces to each other and opposing each other, the capacitor element body being constituted by a plurality of dielectric layers laminated in the opposing direction of the first and second side faces;

a first inner electrode disposed within the capacitor element body, the first inner electrode having a first lead electrode part extending to the third and fourth side faces and a first main electrode part separated by a distance Wg from the third and fourth side faces;

a second inner electrode disposed within the capacitor element body, the second inner electrode having a second lead electrode part extending to the third and fourth side faces and a second main electrode part opposing the first main electrode part in the opposing direction of the first and second side faces and separated by the distance Wg from the third and fourth side faces;

a first terminal electrode disposed on the first end face side of the first, second, third, and fourth side faces each with an electrode width W 1 as a width in the opposing direction of the first and second end faces and connected to the first lead electrode part; and

a second terminal electrode disposed on the second end face side of the first, second, third, and fourth side faces each with an electrode width W 2 as a width in the opposing direction of the first and second end faces while being separated from the first terminal electrode by a distance G shorter than each of the electrode widths W 1 and W 2 and connected to the second lead electrode part;

wherein the first and second inner electrodes are alternately laminated with a dielectric layer of the plurality of dielectric layers in between in the opposing direction of the first and second side faces, while the first or second inner electrode at the outermost layer on each of the first and second side face sides and the first or second side face adjacent to the inner electrode have a distance Cv therebetween shorter than the distance Wg between the first or second main electrode part and the third or fourth side face.

2 . A multilayer capacitor according to claim 1 , wherein the distances Wg and Cv are set such that a ratio of a first inductance value calculated according to the distance Wg as an equivalent series inductance value obtained when the third or fourth side face of the multilayer capacitor is used as a mounting surface to a second inductance value calculated according to the distance Cv as an equivalent series inductance value obtained when the first or second side face of the multilayer capacitor is used as a mounting surface falls within the range of 0.8 to 1.2.

3 . A multilayer capacitor according to claim 1 , wherein each side of the first and second end faces has a length of 0.3 to 0.5 mm, the distance Cv is 10 to 40 μm, and the distance Wg is 40 to 70 μm.

4 . A multilayer capacitor according to claim 3 , wherein the distance Cv is 20 to 30 μm, and the distance Wg is 50 to 70 μm.

5 . A mounting structure for mounting the multilayer capacitor according to claim 1 to a circuit board,

the circuit board comprising through-hole electrodes formed in the circuit board so as to be separated from each other by a distance shorter than that between the first and second lead electrode parts in the opposing direction of the first and second end faces, and mounting electrodes formed on the circuit board so as to be connected to the respective through-hole electrodes and extend outward from the through-hole electrodes;

the mounting structure connecting the first and second terminal electrodes of the multilayer capacitor to the respective mounting electrodes by using one of the first, second, third, and fourth side faces as a mounting surface.

6 . A method of manufacturing a multilayer capacitor comprising a capacitor element body having first and second side faces, each having a substantially rectangular form, opposing each other, third and fourth side faces extending in a longer side direction of the first and second side faces so as to connect the first and second side faces to each other and opposing each other, and substantially square first and second end faces extending in a shorter side direction of the first and second side faces so as to connect the first and second side faces to each other and opposing each other; first and second inner electrodes disposed within the capacitor element body; and first and second terminal electrodes disposed on a surface of the capacitor element body;

the method comprising the steps of:

forming the first and second inner electrodes on respective dielectric layers;

laminating the first and second inner electrodes alternately with a dielectric layer in between, so as to yield a capacitor element body having the first and second inner electrodes arranged therewithin; and

forming the first and second terminal electrodes on the capacitor element body;

wherein the step of forming the first and second inner electrodes forms the first and second inner electrodes such that the first inner electrode has a first lead electrode part extending to the third and fourth side faces and a first main electrode part separated by a distance Wg from the third and fourth side faces and the second inner electrode has a second lead electrode part extending to the third and fourth side faces and a second main electrode part separated by the distance Wg from the third and fourth side faces;

wherein the step of forming the first and second terminal electrodes forms the first terminal electrode disposed on the first end face side of the first, second, third, and fourth side faces each with an electrode width W 1 as a width in the opposing direction of the first and second end faces and connected to the first lead electrode part, and the second terminal electrode disposed on the second end face side of the first, second, third, and fourth side faces each with an electrode width W 2 as a width in the opposing direction of the first and second end faces while being separated from the first terminal electrode by a distance G shorter than each of the electrode widths W 1 , W 2 and connected to the second lead electrode part; and

wherein the steps of forming the first and second inner electrodes and yielding the capacitor element body manufacture the multilayer capacitor by laminating the first and second inner electrodes alternately with the dielectric layer in between such that the first or second inner electrode at the outermost layer on each of the first and second side face sides and the first or second side face adjacent to the inner electrode have a distance Cv therebetween shorter than the distance Wg between the first or second main electrode part and the third or fourth side face, and setting the distances Wg and Cv such that a ratio of a first inductance value calculated according to the distance Wg as an equivalent series inductance value obtained when the third or fourth side face of the multilayer capacitor is used as a mounting surface to a second inductance value calculated according to the distance Cv as an equivalent series inductance value obtained when the first or second side face of the multilayer capacitor is used as a mounting surface falls within the range of 0.8 to 1.2.