Laminated electronic component

A laminated electronic component having a coil formed in a laminated body of pluralities of laminated magnetic material layers and conductor patterns by electrically connecting the conductor patterns adjacent to each other via the magnetic material layers. The magnetic material layers contain a metal magnetic material. The coil has a first end portion close to a bottom surface of the laminated body and a second end portion distant from the bottom surface of the laminated body. The first end portion is electrically connected to a first external terminal disposed on the bottom surface of the laminated body. The second end portion is electrically connected to a second external terminal disposed on the bottom surface of the laminated body via a conductor extending in a lamination direction of the laminated body. An insulator part is disposed between the conductor and the coil.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2016-187244, filed on Sep. 26, 2016, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a laminated electronic component having a coil formed in a laminated body.

BACKGROUND

As shown inFIGS. 5 and 6, conventional laminated electronic components include a component having a coil formed in a laminated body by laminating magnetic material layers51A to51F and conductor patterns52A to52E and by spirally connecting the conductor patterns52A to52E between the magnetic material layers with lead-out ends of the coil led out to longitudinal-direction side surfaces of the laminated body so that the coil is connected between external terminals55,56formed on the longitudinal-direction side surfaces of the laminated body and four surfaces adjacent to these side surfaces.

In recent years, because of miniaturization and higher functionality of mobile devices on which this kind of electronic components is mounted, the number of electronic circuits required for these devices has increased and an area of a mounting board has become smaller. Accordingly, electronic components used for these devices are required to be reduced in size and thickness. Additionally, lower voltages are increasingly used in these devices, so that inductors used in these devices are required to be further improved in DC superposition characteristics. Furthermore, minimization of land patterns for mounting and minimization of distance between adjacent electronic components are performed on mounting boards of these devices so as to mount the electronic components at higher density, and inductors to be mounted on the mounting boards of these devices must be mounted at high density.

One method of improving DC superimposition characteristics of an inductor is to use a material with a high maximum magnetic flux density for a magnetic material constituting an element body of the inductor. Although the conventional laminated electronic components typically have a laminated body made of ferrite, the maximum magnetic flux density of ferrite is as low as about 0.4 T. Therefore, the conventional laminated electronic components have a problem that magnetic saturation easily occurs when a large current is applied. To solve such a problem, the material of the laminated body is switched from ferrite to a metal magnetic material having a high saturation magnetic flux density so as to improve the DC superimposition characteristics (see, e.g., Japanese Laid-Open Patent Publication No. 2013-45985).

However, a metal magnetic material has a lower volume resistivity of material and a lower withstand voltage as compared to ferrite. Therefore, to ensure the insulation and the withstand voltage of the inductor in the conventional laminated electronic components, it is necessary to ensure a sufficient distance between external terminals and to ensure a sufficient distance between positions causing a potential difference, so that it is difficult to achieve sufficient miniaturization. To solve such a problem, the volume resistivity and the withstand voltage are improved by covering a surface of a laminated body having a coil formed therein with ceramics etc. having a high withstand voltage (see, e.g., Japanese Patent No. 5190331).

The conventional laminated electronic components have external terminals formed on the longitudinal-direction side surfaces of the laminated body and four surfaces adjacent to these side surfaces and therefore have a problem that a solder bridge is formed between the external terminals of adjacent electronic components due to a solder fillet at the time of mounting and soldering on a mounting board, a positional displacement of a mounting position at the time of mounting on the mounting board, etc., causing a short circuit. Therefore, it is difficult to mount the electronic components on a mounting board on which the components are mounted at a high density as described above. To solve such a problem, a laminated electronic component having external terminals formed on the longitudinal-direction side surfaces of the laminated body and four surfaces adjacent to these side surfaces is covered with an insulator film except a bottom surface (see, e.g., Japanese Laid-Open Patent Publication No. 2012-256758).

On the other hand, as shown inFIGS. 7 and 8, magnetic material layers71A to71E are provided with conductor patterns72A to72E and conductors73,74penetrating the magnetic material layers, and a coil is formed in a laminated body by laminating the magnetic material layers71A to71F and the conductor patterns72A to72E and by spirally connecting the conductor patterns72A to72E between the magnetic material layers in the laminated body provided with the conductors73,74such that both ends of the coil are led out by the conductors73,74to a bottom surface of the laminated body and connected to external terminals75,76formed on the bottom surface of the laminated body (see, e.g., Japanese Examined Patent Application Publication No. 62-29886).

SUMMARY

The present disclosure provides a laminated electronic component having a coil formed in a laminated body of pluralities of alternately laminated magnetic material layers and conductor patterns by electrically connecting the conductor patterns adjacent to each other via the magnetic material layers. The magnetic material layers contain a metal magnetic material. The coil has a first end portion close to a bottom surface of the laminated body and a second end portion distant from the bottom surface of the laminated body. The first end portion is electrically connected to a first external terminal disposed on the bottom surface of the laminated body. The second end portion is electrically connected to a second external terminal disposed on the bottom surface of the laminated body via a conductor extending in a lamination direction of the laminated body. An insulator part is disposed between the conductor and the coil.

DETAILED DESCRIPTION

However, in the laminated electronic component described in Japanese Laid-Open Patent Publication No. 2012-256758, since the thickness of the insulator film is added to the element dimension, the shape of the laminated body must be made smaller by the thickness of the insulator film, and the component has a problem that the desired inductance and DC superimposition characteristics are difficult to ensure. In the laminated electronic component described in Japanese Examined Patent Application Publication No. 62-29886, a sufficient distance must be ensured between the coil and the conductors so as to ensure insulation and withstand voltage in the laminated body, and the component has a problem that the desired inductance and DC superimposition characteristics are difficult to ensure. Furthermore, since such a conventional laminated electronic component has the conductors disposed in the laminated body such that both ends of the coil are connected to the external electrodes, it is difficult to ensure a sufficient magnetic flux passing area in the laminated body as compared to the conventional laminated electronic component shown inFIGS. 6 and 7, and the component has a problem that a desired inductance is not acquired or, even if the desired inductance is acquired, it is difficult to ensure the DC superimposition characteristics without increasing the resistance value of the coil.

It is an object of the present disclosure to solve these problems and to provide a laminated electronic component using a metal magnetic material, having excellent DC superimposition characteristics and higher insulation and withstand voltage characteristics, and suitable for high-density mounting.

The present disclosure provides a laminated electronic component having a coil formed in a laminated body by laminating magnetic material layers and conductor patterns and by connecting the conductor patterns between the magnetic material layers, wherein the magnetic material layers are made of a metal magnetic material, wherein the coil has two lead-out ends respectively led out to a bottom surface of the laminated body and connected to a pair of external terminals formed on the bottom surface of the laminated body, and wherein an insulator part is formed between the coil and a conductor connecting the lead-out end of the coil distant from the bottom surface of the laminated body to the external terminal.

In other words, the present disclosure provides a laminated electronic component which includes a coil, a laminated body and an insulator part. The coil is formed in the laminated body of pluralities of alternately laminated magnetic material layers and conductor patterns by electrically connecting the conductor patterns adjacent to each other via the magnetic material layers. The magnetic material layers contain a metal magnetic material. The coil has a first end portion close to a bottom surface of the laminated body and a second end portion distant from the bottom surface of the laminated body. The first end portion is electrically connected to a first external terminal disposed on the bottom surface of the laminated body. The second end portion is electrically connected to a second external terminal disposed on the bottom surface of the laminated body via a conductor extending in a lamination direction of the laminated body. The insulator part is disposed between the conductor and the coil.

The present disclosure also provides a laminated electronic component having a coil formed in a laminated body by laminating magnetic material layers and conductor patterns and by connecting the conductor patterns between the magnetic material layers. The magnetic material layers are made of a metal magnetic material. The coil has two lead-out ends respectively led out to a bottom surface of the laminated body and connected to a pair of external terminals formed on the bottom surface of the laminated body. An insulator part is formed between the coil and the external terminals.

In other words, the present disclosure also provides a laminated electronic component which includes a coil, a laminated body and an insulator part. The coil is formed in the laminated body of pluralities of alternately laminated magnetic material layers and conductor patterns by electrically connecting the conductor patterns adjacent to each other via the magnetic material layers. The magnetic material layers contain a metal magnetic material. The coil has a first end portion close to a bottom surface of the laminated body and a second end portion distant from the bottom surface of the laminated body. The first end portion is electrically connected to a first external terminal disposed on the bottom surface of the laminated body. The second end portion is electrically connected to a second external terminal disposed on the bottom surface of the laminated body. The insulator part is disposed between the conductor pattern having the first end portion and at least one of the first external terminal and the second external terminal.

The laminated electronic component of the present disclosure has a coil formed in a laminated body by laminating magnetic material layers and conductor patterns and by connecting the conductor patterns between the magnetic material layers. The magnetic material layers are made of a metal magnetic material. The coil has two lead-out ends respectively led out to a bottom surface of the laminated body and connected to a pair of external terminals formed on the bottom surface of the laminated body. An insulator part is formed between the coil and a conductor connecting the lead-out end of the coil distant from the bottom surface of the laminated body to the external terminal. Therefore, the laminated electronic component has excellent DC superimposition characteristics and high insulation and withstand voltage characteristics and can be mounted at high density on a mounting board.

The laminated electronic component of the present disclosure has a coil formed in a laminated body by laminating magnetic material layers and conductor patterns and by connecting the conductor patterns between the magnetic material layers. The magnetic material layers are made of a metal magnetic material. The coil has two lead-out ends respectively led out to a bottom surface of the laminated body and connected to a pair of external terminals formed on the bottom surface of the laminated body. An insulator part is formed between the coil and the external terminals. Therefore, the laminated electronic component has excellent DC superimposition characteristics and high insulation and withstand voltage characteristics and can be mounted at high density on a mounting board.

A laminated electronic component of the present disclosure has a coil formed in a laminated body by laminating magnetic material layers made of a metal magnetic material and conductor patterns and by connecting the conductor patterns between the magnetic material layers. The laminated body has a bottom surface orthogonal to a lamination direction and having an external terminal disposed thereon and a side surface adjacent to the bottom surface and parallel to the lamination direction. In the coil, both lead-out ends are led out via respective conductors to the bottom surface of the laminated body and respectively electrically connected to a pair of external terminals formed on the bottom surface of the laminated body. An insulator part is formed between the coil and the conductor electrically connecting the lead-out end (second end portion) of the coil distant from the bottom surface of the laminated body to the external terminal, or between the coil and the external terminal.

Therefore, the laminated electronic component of the present disclosure has no external terminal on the side surface of the laminated body, so that no solder fillet is formed on the side surface at the time of soldering to a mounting board.

In the laminated electronic component of the present disclosure, the electric distance between positions causing a potential difference and the magnetic flux passing area in the laminated body can be made larger than those of the conventional laminated electronic component shown inFIGS. 7 and 8.

Furthermore, since the laminated electronic component of the present disclosure has no external terminal formed on the side surface, the volume of the laminated body can be made larger than that of the conventional laminated electronic component shown inFIGS. 5 and 6by the volume of the external terminal and the insulator film on the side surface, which reduces the magnetic flux density per unit volume, so that the characteristics can be improved.

Embodiments

Embodiments of the laminated electronic component of the present disclosure will now be described with reference toFIGS. 1 to 4.

FIG. 1is an exploded perspective view of a first embodiment of the laminated electronic component of the present disclosure.

InFIG. 1, reference numerals10,11A to11G, and12A to12E denote a laminated body, magnetic material layers, and conductor patterns, respectively. The laminated body10has a bottom surface orthogonal to a lamination direction and having an external terminal disposed thereon, and four side surfaces adjacent to the bottom surface and parallel to the lamination direction. The four side surfaces are two longitudinal-direction side surfaces perpendicular to the longitudinal direction of the rectangular magnetic material layers and two lateral-direction side surfaces parallel to the longitudinal direction of the magnetic material layers.

The laminated body10is formed by laminating the magnetic material layers11A to11G and the conductor patterns12A to12E. The magnetic material layers11A to11G are made of a metal magnetic material such as metal magnetic powder of Fe, Si, Fe—Si—Cr, Fe—Si—Al, Fe—Ni—Al, Fe—Cr—Al, amorphous, etc. The conductor patterns12A to12E are made of a conductor paste that is a metal material such as silver, silver-based material, gold, gold-based material, copper, copper-based material, etc. made into a paste form.

The magnetic material layer11A is formed into a rectangular sheet shape and has a first through hole formed at a position corresponding to, out of two lead-out ends of a coil pattern described later, a first end portion close to a bottom surface of the laminated body and a second through-hole formed at a position corresponding to a second end portion distant from the bottom surface of the laminated body. Furthermore, a third through-hole is formed between a portion close to the second through-hole corresponding to the conductor pattern12A described later and the second through-hole. Conductors13,14A having the same thickness as the magnetic material layer11A are formed in the through-holes (the first through-hole and the second through-hole) of the magnetic material layer11A at the positions corresponding to the lead-out ends of the coil pattern. The conductors13,14A are formed by printing using the same material as the material forming the conductor pattern. Additionally, an insulator part17A is formed in the third through-hole formed between the second through-hole and the portion close to the second through-hole corresponding to the conductor pattern12A. The insulator part17A is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11A.

The magnetic material layer11B is formed into a rectangular sheet shape and has a first through-hole formed at a position corresponding to the first end portion and the conductor13, a second through-hole formed at a position corresponding to the second end portion of the coil pattern, and a third through-hole formed between the second through-hole and a portion of the conductor pattern12A described later close to the second through-hole. A conductor14B having the same thickness as the magnetic material layer11B is formed in the second through-hole of the magnetic material layer11B. The conductor14B is formed by printing using the same material as the material forming the conductor pattern12A described later. A conductor is also formed in the first through-hole of the magnetic material layer11B in the same way (not shown). The conductor pattern12A is formed on an upper surface of the magnetic material layer11B (the surface on the side opposite to the bottom surface of the laminated body10). This conductor pattern12A is formed for less than one turn and has the first end portion connected to the conductor13via the conductor in the through-hole formed in the magnetic material layer11B. In the third through-hole, an insulator part17B is formed having a thickness that is the sum of the thickness of the magnetic material layer11B and the thickness of the conductor pattern12A. The insulator part17B is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11B.

The magnetic material layer11C is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern, a third through-hole formed between the second through-hole and a portion close to the second through-hole corresponding to the conductor pattern12A described later, and a first through-hole formed at a position corresponding to the other end of the conductor pattern12A different from the first end portion. A conductor14C having the same thickness as the magnetic material layer11C is formed in the second through-hole of the magnetic material layer11C. The conductor14C is formed by printing using the same material as the conductor pattern12B described later. A conductor is also formed in the first through-hole of the magnetic material layer11C in the same way (not shown). The conductor pattern12B is formed on the upper surface of the magnetic material layer11C. This conductor pattern12B is formed for less than one turn and has one end connected to the other end of the conductor pattern12A via the conductor in the first through-hole formed in the magnetic material layer11C. In the third through-hole, an insulator part17C is formed having a thickness that is the sum of the thickness of the magnetic material layer11C and the thickness of the conductor pattern12B. The insulator part17C is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11C.

The magnetic material layer11D is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern, a third through-hole formed between the second through-hole and a portion of the conductor pattern12C described later close to the second through-hole, and a first through-hole formed at a position corresponding to the other end of the conductor pattern12B. A conductor14D having the same thickness as the magnetic material layer11D is formed in the second through-hole of the magnetic material layer11D. The conductor14D is formed by printing using the same material as the conductor pattern12C described later. A conductor is also formed in the first through-hole of the magnetic material layer11D in the same way (not shown). The conductor pattern12C is formed on the upper surface of the magnetic material layer11D. This conductor pattern12C is formed for less than one turn and has one end connected to the other end of the conductor pattern12B via the conductor in the first through-hole formed in the magnetic material layer11D. In the third through-hole, an insulator part17D is formed having a thickness that is the sum of the thickness of the magnetic material layer11D and the thickness of the conductor pattern12C. The insulator part17D is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11D.

The magnetic material layer11E is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern, a third through-hole formed between the second through-hole and a portion close to the second through-hole corresponding to the conductor pattern12C, and a first through-hole formed at a position corresponding to the other end of the conductor pattern12C. A conductor14E having the same thickness as the magnetic material layer11E is formed in the second through-hole of the magnetic material layer11E. The conductor14E is formed by printing using the same material as the conductor pattern12D described later. A conductor is also formed in the first through-hole of the magnetic material layer11E in the same way (not shown). The conductor pattern12D is formed on the upper surface of the magnetic material layer11E. This conductor pattern12D is formed for less than one turn and has one end connected to the other end of the conductor pattern12C via the conductor in the through-hole formed in the magnetic material layer11E. In the third through-hole, an insulator part17E is formed having a thickness that is the sum of the thickness of the magnetic material layer11E and the thickness of the conductor pattern12D. The insulator part17E is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11E.

The magnetic material layer11F is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern, a third through-hole formed between the second through-hole and a portion close to the second through-hole at a position corresponding to the conductor pattern12C, and a first through-hole formed at a position corresponding to the other end of the conductor pattern12D. Respective conductors having the same thickness as the magnetic material layer11F are formed in the first through-hole and the second through-hole of the magnetic material layer11F. The conductors are formed by printing using the same material as the conductor pattern12E described later. An insulator part17F having the same thickness as the magnetic material layer11E is formed in the third through-hole. The insulator part17F is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer11F. The conductor pattern12E is formed on the upper surface of the magnetic material layer11F. This conductor pattern12E is formed for less than one turn and has one end connected to the other end of the conductor pattern12D via the conductor in the first through-hole formed in the magnetic material layer11F and the other end connected to the conductor14E via the conductor in the second through-hole formed in the magnetic material layer11F.

The magnetic material layer11G for protecting the conductor pattern is formed on the magnetic material layer11F having the conductor pattern12E formed thereon.

By spirally connecting the conductor patterns12A to12E between the magnetic material layers in this way, the coil pattern is formed in the laminated body. In this laminated body10, the respective conductors connected to the first end portion and the second end portion of the coil pattern have surfaces partially exposed on the bottom surface. In this case, the conductor connected to the second end portion of the coil pattern extends in the lamination direction of the magnetic material layers between the bottom surface of the laminated body10and the second end portion. This laminated body10has a pair of external terminals15,16formed on the bottom surface as shown inFIG. 2, and both of the lead-out ends of the coil pattern are respectively connected via the conductors so that a coil is connected between the paired external terminals15,16.

In this laminated body10, between the conductor connected to the second end portion and the coil pattern, an insulator part is formed that extends in the lamination direction of the magnetic material layers from a surface of the second end portion of the coil pattern on the bottom surface side of the laminated body to the bottom surface of the laminated body. As a result, better insulation and withstand voltage characteristics can be achieved.

The laminated electronic component formed in this way has an inductance of 1 μH, a DC resistance value (Rdc) of 205 mΩ, and a rated current (Isat) of 1.64 A as the current value at −30% inductance relative to the inductance without a load when DC superimposition characteristics of an inductor are measured. Since the conventional laminated electronic component shown inFIGS. 3 and 4has the values of 1.03 μH, 212 mΩ, and 1.58 A, respectively, and the conventional laminated electronic component shown inFIGS. 5 and 6has the values of 1.03 μH, 205 mΩ, and 1.60 A, respectively, the laminated electronic component of the present disclosure has excellent DC superimposition characteristics and high insulation and withstand voltage characteristics as compared to the conventional laminated electronic components.

The inductance and the DC superimposition characteristics were measured by using LCR Meter 4285A, and the DC resistance value was measured by using Milliohm Meter 4338B.

FIG. 3is an exploded perspective view of a second embodiment of the laminated electronic component of the present disclosure. In the second embodiment, an insulator part is partially disposed on the bottom surface side of the laminated electronic component. As a result, better DC superimposition characteristics and better insulation and withstand voltage characteristics can be achieved.

A magnetic material layer31A is formed into a rectangular sheet shape and has respective through-holes formed at positions corresponding to two lead-out ends of a coil pattern described later. In particular, a first through-hole is formed at a position corresponding to, out of the two lead-out ends, a first end portion close to a bottom surface of a laminated body, and a second through-hole is formed at a position corresponding to a second end portion distant from the bottom surface of the laminated body. Furthermore, a third through-hole is formed between the second through-hole and a portion close to the second through-hole corresponding to a conductor pattern32A described later. Conductors33,34A having the same thickness as the magnetic material layer31A are formed in the through-holes (the first through-hole and the second through-hole) of the magnetic material layer31A at the positions corresponding to the lead-out ends of the coil pattern. The conductors33,34A are formed by printing using the same material as the material forming the conductor pattern. Additionally, an insulator part37A is formed in the third through-hole. The insulator part37A is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer31A.

A magnetic material layer31B is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a third through-hole formed between the second through-hole and a portion of the conductor pattern32A described later close to the second through-hole. A conductor34B having the same thickness as the magnetic material layer31B is formed in the second through-hole of the magnetic material layer31B. The conductor34B is formed by printing using the same material as the material forming the conductor pattern32A. A conductor is also formed in a first through-hole of the magnetic material layer31B in the same way (not shown). The conductor pattern32A is formed on the upper surface of the magnetic material layer31B. This conductor pattern32A is formed for less than one turn and has one end connected to the conductor33via the conductor in the first through-hole formed in the magnetic material layer31B. In the third through-hole, an insulator part37B is formed having a thickness that is the sum of the thickness of the magnetic material layer31B and the thickness of the conductor pattern32A. The insulator part37B is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer31B.

A magnetic material layer31C is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern32A. A conductor34C having the same thickness as the magnetic material layer31C is formed in the second through-hole of the magnetic material layer31C. The conductor34C is formed by printing using the same material as the material forming a conductor pattern32B described later. A conductor is also formed in the first through-hole of the magnetic material layer31C in the same way (not shown). The conductor pattern32B is formed on the upper surface of the magnetic material layer31C. This conductor pattern32B is formed for less than one turn and has one end connected to the other end of the conductor pattern32A via the conductor in the first through-hole formed in the magnetic material layer31C.

A magnetic material layer31D is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern32B. A conductor34D having the same thickness as the magnetic material layer31D is formed in the second through-hole of the magnetic material layer31D. The conductor34D is formed by printing using the same material as the material forming a conductor pattern32C described later. A conductor is also formed in the first through-hole of the magnetic material layer31D in the same way (not shown). The conductor pattern32C is formed on the upper surface of the magnetic material layer31D. This conductor pattern32C is formed for less than one turn and has one end connected to the other end of the conductor pattern32B via the conductor in the through-hole formed in the magnetic material layer31D.

A magnetic material layer31E is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern32C. A conductor34E having the same thickness as the magnetic material layer31E is formed in the second through-hole of the magnetic material layer31E. The conductor34E is formed by printing using the same material as the material forming a conductor pattern32D described later. A conductor is also formed in the first through-hole of the magnetic material layer31E in the same way (not shown). The conductor pattern32D is formed on the upper surface of the magnetic material layer31E. This conductor pattern32D is formed for less than one turn and has one end connected to the other end of the conductor pattern32C via the conductor in the through-hole formed in the magnetic material layer31E.

A magnetic material layer31F is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern32D. Respective conductors having the same thickness as the magnetic material layer31F are formed in the first through-hole and the second through-hole of the magnetic material layer31F. The conductors are formed by printing using the same material as a conductor pattern32E described later. The conductor pattern32E is formed on the upper surface of the magnetic material layer31F. This conductor pattern32E is formed for less than one turn and has one end connected to the other end of the conductor pattern32D via the conductor in the first through-hole formed in the magnetic material layer31F and the other end connected to the conductor34E via the conductor in the second through-hole formed in the magnetic material layer31F.

A magnetic material layer31G for protecting the conductor pattern is formed on the magnetic material layer31F having the conductor pattern32E formed thereon.

By spirally connecting the conductor patterns32A to32E between the magnetic material layers in this way, the coil pattern is formed in the laminated body. In this laminated body30, the respective conductors connected to the first end portion and the second end portion of the coil pattern have surfaces partially exposed on the bottom surface. In this case, the conductor connected to the second end portion of the coil pattern extends in the lamination direction of the magnetic material layers between the bottom surface of the laminated body30and the second end portion. This laminated body30has a pair of the external terminals15,16formed on the bottom surface as shown inFIG. 2, and the two lead-out ends (the first end portion and the second end portion) of the coil pattern are respectively connected via the conductors so that a coil is connected between the paired external terminals15,16.

In this laminated body30, between the conductor connected to the second end portion and the coil pattern, an insulator part is formed that extends in the lamination direction of the magnetic material layers from the bottom surface of the laminated body30to the first layer of the coil pattern, i.e., from a surface of the conductor pattern32A having the first end portion of the coil pattern on the side opposite to the bottom surface side of the laminated body to the bottom surface of the laminated body.

FIG. 4is an exploded perspective view of a third embodiment of the laminated electronic component of the present disclosure. In the third embodiment, an insulator part is disposed between a coil and an external terminal. As a result, better DC superimposition characteristics and better insulation and withstand voltage characteristics can be achieved.

A magnetic material layer41A is formed into a rectangular sheet shape and has respective through-holes formed at positions corresponding to two lead-out ends of a coil pattern described later. In particular, a first through-hole is formed at a position corresponding to, out of the two lead-out ends, a first end portion close to a bottom surface of a laminated body, and a second through-hole is formed at a position corresponding to a second end portion distant from the bottom surface of the laminated body. A conductor43and a conductor44A both having the same thickness as the magnetic material layer41A are formed in the first through-hole and the second through-hole, respectively. The conductors43,44A are formed by printing using the same material as the material forming the conductor pattern. Additionally, this magnetic material layer41A has a third through-hole formed at least at a position where a conductor pattern42A described later and an external terminal described later face each other. An insulator part47is formed in the third through-hole. The insulator part47is made of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and is particularly made of a material higher in volume resistivity and withstand voltage than the material constituting the magnetic material layer41A.

A magnetic material layer41B is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the conductor43. A conductor44B having the same thickness as the magnetic material layer41B is formed in the second through-hole of the magnetic material layer41B. The conductor44B is formed by printing using the same material as the material forming the conductor pattern42A described later. A conductor is also formed in the first through-hole of the magnetic material layer41B in the same way (not shown). The conductor pattern42A is formed on the upper surface of the magnetic material layer41B. This conductor pattern42A is formed for less than one turn and has one end connected to the conductor43via the conductor in the first through-hole formed in the magnetic material layer41B.

A magnetic material layer41C is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern42A. A conductor44C having the same thickness as the magnetic material layer41C is formed in the second through-hole of the magnetic material layer41C. The conductor44C is formed by printing using the same material as the material forming a conductor pattern42B described later. A conductor is also formed in the first through-hole of the magnetic material layer41C in the same way (not shown). The conductor pattern42B is formed on the upper surface of the magnetic material layer41C. This conductor pattern42B is formed for less than one turn and has one end connected to the other end of the conductor pattern42A via the conductor in the first through-hole formed in the magnetic material layer41C.

A magnetic material layer41D is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern42B. A conductor44D having the same thickness as the magnetic material layer41D is formed in the second through-hole of the magnetic material layer41D. The conductor44D is formed by printing using the same material as the material forming a conductor pattern42C described later. A conductor is also formed in the first through-hole of the magnetic material layer41D in the same way (not shown). The conductor pattern42C is formed on the upper surface of the magnetic material layer41D. This conductor pattern42C is formed for less than one turn and has one end connected to the other end of the conductor pattern42B via the conductor in the first through-hole formed in the magnetic material layer41D.

A magnetic material layer41E is formed into a rectangular sheet shape and has a through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern42C. A conductor44E having the same thickness as the magnetic material layer41E is formed in the second through-hole of the magnetic material layer41E. The conductor44E is formed by printing using the same material as the material forming a conductor pattern42D described later. A conductor is also formed in the first through-hole of the magnetic material layer41E in the same way (not shown). The conductor pattern42D is formed on the upper surface of the magnetic material layer41E. This conductor pattern42D is formed for less than one turn and has one end connected to the other end of the conductor pattern42C via the conductor in the first through-hole formed in the magnetic material layer41E.

A magnetic material layer41F is formed into a rectangular sheet shape and has a second through-hole formed at a position corresponding to the second end portion of the coil pattern and a first through-hole formed at a position corresponding to the other end of the conductor pattern42D. Conductors having the same thickness as the magnetic material layer41F are formed in the first through-hole and the second through-hole of the magnetic material layer41F. The conductors are formed by printing using the same material as the material forming a conductor pattern42E described later. The conductor pattern42E is formed on the upper surface of the magnetic material layer41F. This conductor pattern42E is formed for less than one turn and has one end connected to the other end of the conductor pattern42D via the conductor in the first through-hole formed in the magnetic material layer41F and the other end connected to the conductor44E via the conductor in the second through-hole formed in the magnetic material layer41F.

A magnetic material layer41G for protecting the conductor pattern is formed on the magnetic material layer41F having the conductor pattern42E formed thereon.

By spirally connecting the conductor patterns42A to42E between the magnetic material layers in this way, the coil pattern is formed in the laminated body. In this laminated body40, the respective conductors connected to the first end portion and the second end portion of the coil pattern have surfaces partially exposed on the bottom surface. In this case, the conductor connected to the second end portion of the coil pattern extends in the lamination direction of the magnetic material layers between the bottom surface of the laminated body40and the second end portion. This laminated body40has a pair of the external terminals15,16formed on the bottom surface as shown inFIG. 2, and the two lead-out ends (the first end portion and the second end portion) of the coil pattern are respectively connected via the conductors so that a coil is connected between the paired external terminals15,16. In this laminated body40, an insulator part is formed between the coil pattern and the external terminal.

Although the embodiments of the laminated electronic component of the present disclosure have been described, the present disclosure is not limited to the embodiments. For example, in the embodiments, the external terminals are formed on the bottom surface of the laminated body such that the terminals are visible from the side surfaces; however, the external terminals may be formed on the bottom surface of the laminated body away from the sides adjacent to the side surfaces such that the terminals are invisible from the side surfaces. In the embodiments, the bottom surface of the laminated body may be provided with an insulator layer formed of an insulating material, for example, a dielectric material such as glass and glass ceramics, a magnetic material such as ferrite, or a nonmagnetic material, and the external terminals may be formed on the insulator layer. In this case, the insulator layer may be made of a material higher in volume resistivity and withstand voltage than the material constituting the laminated body.

In the first embodiment, the insulator part is in contact with the laminated-body bottom surface side of the lead-out end of the coil pattern distant from the bottom surface of the laminated body and extends to the bottom surface of the laminated body in the description; however, the insulator part may be disposed between the coil pattern and the conductor connecting the lead-out end of the coil pattern distant from the bottom surface of the laminated body to the external terminal and therefore can be changed in position, shape, size, etc. depending on a portion having a large potential difference by being formed on the side of the lead-out end of the coil pattern distant from the bottom surface of the laminated body in contact with the lead-out end of the coil pattern distant from the bottom surface of the laminated body or by being formed partially between the lead-out end of the coil pattern distant from the bottom surface of the laminated body and the bottom surface of the laminated body.

In the second embodiment, the insulator part is formed between the coil pattern and the conductor connecting the lead-out end of the coil pattern distant from the bottom surface of the laminated body to the external terminal, from the bottom surface of the laminated body to the first layer of the coil pattern in the description; however, the insulator part may be formed in a portion of the coil pattern on the bottom surface side of the laminated body and may be formed from the bottom surface of the laminated body to an arbitrary height such as a second layer and a third layer of the coil pattern.

In the third embodiment, the insulator part is formed on the other end portion side of the conductor pattern into the same shape as the conductor pattern; however, the insulator part can be changed in position, shape, size, etc. depending on a portion having a large potential difference.

It is to be understood that although the present disclosure has been described with regard to preferred embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope and spirit of the disclosure, and such other embodiments and variants are intended to be covered by the following claims.