An inductor includes a magnetic body including a magnetic substance; a substrate disposed within the magnetic body; and an internal electrode disposed on at least one of an upper surface and a lower surface of the substrate. The substrate is disposed on an inclined with respect to at least one surface of the magnetic body.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Korean Patent Application No. 10-2015-0060289, filed on Apr. 29, 2015 with the Korean Intellectual Property Office, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present inventive concept relates to an inductor.

BACKGROUND

An inductor, together with a resistor and a capacitor, is a key passive element constituting an electronic circuit. Inductors are used in components to cancel noise or to form an LC resonance circuit. Inductors may be classified as winding type inductors, laminated type inductors, thin film type inductors, and the like, according to the structure thereof.

A winding type inductor may be formed by winding a coil around a ferrite core. A winding type inductor may have stray capacitance generated between coil portions, and accordingly, when the number of turns of a coil is increased to obtain high capacity inductance, degradation of high frequency characteristics may occur.

A laminated type inductor may be formed by laminating a plurality of ceramic sheets. In a laminated type inductor, coil-like metal patterns are formed on respective ceramic sheets, and the coil-like metal patterns may be sequentially connected to one another by a plurality of conductive vias provided in the ceramic sheets. Laminated type inductors are appropriate for mass-production, and have excellent high frequency characteristics compared to winding type inductors.

However, in a laminated type inductor, metal patterns are formed of a material having a low saturation magnetization value. When a laminated type inductor is manufactured to have a small size, the number of laminations of the metal patterns is limited, and this may lead to a degradation in DC superposition characteristics, thereby resulting in a failure to obtain a sufficient current.

A thin film type inductor may use a material having a high saturation magnetization value, and even when a thin film type inductor is manufactured to have a small size, an internal circuit pattern thereof may be easily formed in comparison to a laminated type inductor. Thus, research has been actively undertaken into thin film type inductors.

When a thin film type inductor is manufactured on a large scale, a line width or thickness of a coil may be increased, thereby eliminating degradation in product characteristics due to an increase in series resistance.

However, when a thin film type inductor is manufactured to have a small size, an increase in the line width or thickness of a coil is limited. Thus, delamination, cracks, and the like may occur between internal electrodes formed within the inductor and a substrate, and between magnetic substances of an inductor body during a chip-cutting process.

SUMMARY

An aspect of the present inventive concept provides an inductor having high capacity characteristics and allowing for reliability improvements in a manufacturing process by preventing defects due to delamination, cracks, and the like.

According to an aspect of the present inventive concept, an inductor includes: a magnetic body including a magnetic substance; a substrate disposed within the magnetic body; and an internal electrode disposed on at least one of an upper surface and a lower surface of the substrate, the substrate being disposed on an inclined with respect to at least one surface of the magnetic body.

In addition, a minimum distance of the distances from the upper and lower surfaces of the magnetic body to the portion thereof to which the substrate is exposed may be 60 μm or more.

In addition, when the internal electrode is disposed on the upper surface or the lower surface of the substrate to be exposed to one end surface of the magnetic body, a distance from the upper surface of the magnetic body to a portion of the end surface to which the internal electrode is exposed may be 100 μm or more, and a distance from the lower surface of the magnetic body to a portion of the end surface to which the internal electrode is exposed may be 150 μm or more.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present inventive concept will be described as follows with reference to the attached drawings.

Spatially relative terms, such as “above,” “upper,” “below,” and “lower” and the like, may be used herein for ease of description to describe one element's relationship to another element(s) as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “upper,” or “above” other elements would then be oriented “lower,” or “below” the other elements or features. Thus, the term “above” can encompass both the above and below orientations depending on a particular direction of the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

Hereinafter, embodiments of the present inventive concept will be described with reference to schematic views illustrating embodiments of the present inventive concept. In the drawings, for example, due to manufacturing techniques and/or tolerances, modifications of the shape shown may be estimated. Thus, embodiments of the present inventive concept should not be construed as being limited to the particular shapes of regions shown herein, for example, to include a change in shape results in manufacturing. The following embodiments may also be constituted by one or a combination thereof.

The contents of the present inventive concept described below may have a variety of configurations and propose only a configuration herein, but are not limited thereto.

FIG. 1is a perspective view of an inductor100according to an embodiment of the present inventive concept.FIG. 2is a cross-sectional view of the inductor100illustrated inFIG. 1, taken along line A-A′.

As shown inFIGS. 1 and 2, a thickness direction of a magnetic body10is referred to as “T”, a length direction thereof is referred to as “L”, and a width direction thereof is referred to as “W”. Surfaces facing an upper surface and a lower surface of a substrate30disposed inside a magnetic body10are defined as an upper surface and a lower surface of the magnetic body10, respectively. Surfaces through which the substrate30is exposed outwardly from the magnetic body10are defined as first and second end surfaces of the magnetic body10, and surfaces adjacent to the first and second end surfaces in the length or width direction are defined as third and fourth side surfaces. In this case, the upper surface and the lower surface of the magnetic body10are adjacent to the first and second end surfaces in the thickness direction.

Referring toFIGS. 1 and 2, the inductor100according to an exemplary embodiment of the present inventive concept may include the magnetic body10including a magnetic substance, the substrate30disposed within the magnetic body10, and internal electrodes41and42disposed on at least one of the upper surface and the lower surface of the substrate30, the substrate30being disposed on an incline with respect to at least one surface of the magnetic body10.

In general, an inductor-manufacturing process may be subjected to a process of cutting a magnetic body (hereinafter referred to as a “bulk magnetic body”) for manufacturing a plurality of inductors into individual inductor units. In this case, defects such as cracks, delamination, and the like may occur in the magnetic body mainly from cut surfaces of the magnetic body, due to differences in physical properties among the internal electrodes, the substrate, and the magnetic substance.

In particular, when distances from the upper surface and the lower surface of the magnetic body to the internal electrodes and the substrate are insufficiently secured in order to miniaturize the inductor, the possibility of incurring defects among the internal electrodes, the substrate, and the magnetic body due to stress resulting from the cutting process applied to the magnetic body may be increased.

When distances from the upper surface and the lower surface of the magnetic body to the internal electrodes and the substrate are increased in order to prevent defects such as cracks, delamination, and the like, miniaturization of the inductor may not be feasible. When an area occupied by the internal electrodes is reduced, the capacity of the inductor may be decreased.

In the inductor100according to an exemplary embodiment of the present inventive concept, the substrate30on which the internal electrodes41and42are disposed may be disposed on an incline, and thus a size of the magnetic body10may be maintained, and distances between the internal electrodes41and42and the upper surface and the lower surface of the magnetic body10may be increased, thereby preventing the occurrence of cracks, delamination, and the like during a cutting process.

In addition, a length of the substrate30disposed within the magnetic body10may be increased, and thus the area occupied by the internal electrodes41and42may be increased, thereby increasing the capacity of the inductor100.

Referring toFIGS. 1 and 2, the substrate30disposed within the magnetic body10may be exposed to at least one external surface of the magnetic body10. On the surface of the magnetic body10to which the substrate30is exposed, a distance from the upper surface of the magnetic body10to a portion thereof to which the substrate30is exposed may be different from a distance from the lower surface of the magnetic body10to the portion thereof to which the substrate30is exposed.

In this case, it may be advantageous to dispose the substrate away from the upper surface and the lower surface of the magnetic body in order to prevent cracks from occurring in the vicinity of the substrate positioned on a cut surface of the magnetic body due to stress caused when the bulk magnetic body is cut into respective units. In an exemplary embodiment of the present inventive concept, a minimum distance of the distances from the upper and lower surfaces of the magnetic body10to the portion thereof to which the substrate30is exposed may be set to 60 μm or more.

In particular, in the case of the inductor100in which a thickness thereof, that is, a distance from the upper surface to the lower surface of the magnetic body10, is 0.8 mm or less, a minimum distance of the distances from the upper and lower surfaces of the magnetic body10to the portion thereof to which the substrate30is exposed may preferably be set to 60 μm or more, in order to prevent defects during a cutting process.

In addition, when the substrate30is exposed to the first end surface and the second end surface of the magnetic body10, a distance from the lower surface of the magnetic body10to a portion of the first end surface to which the substrate30is exposed may be different from a distance from the lower surface of the magnetic body10to a portion of the second end surface to which the substrate30is exposed. In this case, a minimum distance of the distances from the upper and lower surfaces of the magnetic body10to the portions thereof to which the substrate30is exposed may be set to 60 μm or more.

Referring toFIGS. 1 and 2, the internal electrode41or42formed within the magnetic body10may be disposed on the upper surface or the lower surface of the substrate30to be exposed to one end surface of the magnetic body10. When the internal electrode41or42is disposed on the upper surface of the substrate30to be exposed to one end surface of the magnetic body10, a distance from the upper surface of the magnetic body10to a portion of the end surface to which the internal electrode41or42is exposed may preferably be set to 100 μm or more. When the internal electrode41or42is disposed on the lower surface of the substrate30to be exposed to one end surface of the magnetic body10, a distance from the lower surface of the magnetic body10to a portion of the end surface to which the internal electrode41or42is exposed may preferably be set to 150 μm or more.

Cutting stress occurring when a bulk magnetic body is cut into individual inductor units due to differences in physical properties among the internal electrodes, the substrate, and the magnetic substance filling the magnetic body10may more significantly act on spaces between the internal electrodes and the magnetic body, rather than on spaces between the substrate30and the magnetic substance. Therefore, distances from the upper and lower surfaces of the magnetic body10to the internal electrodes41and42may preferably be greater than distances from the upper and lower surfaces of the magnetic body10to the substrate30.

As described above, a distance from the upper surface of the magnetic body10to a portion of the end surface to which the internal electrode41is exposed may preferably be set to 100 μm or more, and a distance from the lower surface of the magnetic body10to a portion of the end surface to which the internal electrode42is exposed may preferably be set to 150 μm or more. In particular, in the case of the inductor100in which a thickness thereof, that is, a distance from the upper surface to the lower surface of the magnetic body10, is 0.8 mm or less, a distance from the upper surface of the magnetic body10to a portion of the end surface to which the internal electrode41is exposed may preferably be set to 100 μm or more, and a distance from the lower surface of the magnetic body10to a portion of the end surface to which the internal electrode42is exposed may preferably be set to 150 μm or more, in order to prevent defects during a cutting process.

In addition, the substrate30may be exposed to the first end surface and the second end surface of the magnetic body10, and the internal electrodes41and42may include a first internal electrode41exposed to the first end surface of the magnetic body10and a second internal electrode42exposed to the second end surface of the magnetic body10. When each of the first and second internal electrodes41and42is disposed on the upper surface or the lower surface of the substrate30to be exposed, distances between the first and second internal electrodes41and42and the upper and lower surfaces of the magnetic body10may be set as below.

When the first internal electrode41is disposed on the upper surface of the substrate30to be exposed to the first end surface of the magnetic body10, a distance from the upper surface of the magnetic body10to a portion of the end surface to which the first internal electrode41is exposed may be set to 100 μm or more. When the first internal electrode41is disposed on the lower surface of the substrate30to be exposed to the first end surface of the magnetic body10, a distance from the lower surface of the magnetic body10to a portion of the end surface to which the first internal electrode41is exposed may be set to 150 μm or more. When the second internal electrode42is disposed on the upper surface of the substrate30to be exposed to the second end surface of the magnetic body10, a distance from the upper surface of the magnetic body10to a portion of the end surface to which the second internal electrode42is exposed may be set to 100 μm or more. When the second internal electrode42is disposed on the lower surface of the substrate30to be exposed to the second end surface of the magnetic body10, a distance from the lower surface of the magnetic body10to a portion of the end surface to which the second internal electrode42is exposed may be set to 150 μm or more.

That is, the internal electrode41or42is exposed outwardly from the magnetic body110while being disposed on the upper surface or the lower surface of the substrate30. When the internal electrode41is disposed on the upper surface of the substrate30to be exposed outwardly from the magnetic body110, the internal electrode41may be spaced apart from the upper surface of the magnetic body110by 100 μm or more. When the internal electrode42is disposed on the lower surface of the substrate30to be exposed outwardly from the magnetic body110, the internal electrode42may be spaced apart from the lower surface of the magnetic body110by 150 μm or more.

Hereinafter, on the basis ofFIG. 2, the inductor100according to the exemplary embodiment of the present inventive concept will be described in detail.

InFIG. 2, the substrate30may be exposed to the first end surface and the second end surface of the magnetic body10, and a distance A from the lower surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed may be shorter than a distance E from the lower surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed.

In addition, a distance B from the upper surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed may be greater than a distance D from the upper surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed.

The internal electrodes41and42may include the first internal electrode41disposed on the upper surface of the substrate30to be exposed to the second end surface of the magnetic body10and the second internal electrode42disposed on the lower surface of the substrate to be exposed to the first end surface of the magnetic body10.

In this case, the distance A from the lower surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed, and the distance D from the upper surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed, may be respectively set to 60 μm or more.

In addition, a distance C from the upper surface of the magnetic body10to a portion of the second end surface thereof to which the first internal electrode41is exposed may be set to 100 μm or more, and a distance F from the lower surface of the magnetic body10to a portion of the first end surface thereof to which the second internal electrode42is exposed may be respectively set to 150 μm or more.

Through such a configuration, defects during a cutting process may be prevented, and high capacity may be formed as described above.

FIG. 3is a perspective view of an inductor200according to another embodiment of the present inventive concept, andFIG. 4is a cross-sectional view of the inductor200illustrated inFIG. 3, taken along line B-B′.

Referring toFIGS. 3 and 4, the magnetic body10may further include an upper cover layer11and a lower cover layer12disposed, respectively, above and below the substrate30and the internal electrodes41and42. The upper cover layer11and the lower cover layer12may serve to prevent degradation in electrical characteristics of the first and second internal electrodes41and42.

InFIGS. 3 and 4, the substrate30may be exposed to the first and second end surfaces of the magnetic body10, and a distance L from the lower surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed may be shorter than a distance P from the lower surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed.

In addition, a distance M from the upper surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed may be greater than a distance O from the upper surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed.

The internal electrodes41and42may include the first internal electrode41disposed on the upper surface of the substrate30to be exposed to the first end surface of the magnetic body10and the second internal electrode42disposed on the lower surface of the substrate30to be exposed to the second end surface of the magnetic body10.

In this case, the distance L from the lower surface of the magnetic body10to a portion of the first end surface thereof to which the substrate30is exposed and the distance O from the upper surface of the magnetic body10to a portion of the second end surface thereof to which the substrate30is exposed may be respectively set to 60 μm or more.

In addition, a distance N from the upper surface of the magnetic body10to a portion of the first end surface thereof to which the first internal electrode41is exposed may be set to 100 μm or more, and a distance Q from the lower surface of the magnetic body10to a portion of the second end surface thereof to which the second internal electrode42is exposed may be set to 150 μm or more.

FIG. 5is a perspective view of an inductor300according to another embodiment of the present inventive concept.

Referring toFIG. 5, an inductor300according to an exemplary embodiment of the present inventive concept may further include first and second external electrodes81and82disposed on the first and second end surfaces of the magnetic body10to be connected to the first and second internal electrodes41and42, respectively.

Hereinafter, respective components configuring the inductor100according to the exemplary embodiment of the present inventive concept will be described.

A material of the magnetic body10is not limited, as long as the material may form the exterior of the inductor100and exhibit magnetic properties. For example, the magnetic body10may be formed by providing a ferrite material or magnetic metal powder.

The ferrite material maybe a ferrite material commonly known in the art such as an Mn—Zn based ferrite, an Ni—Zn based ferrite, an Ni—Zn—Cu based ferrite, an Mn—Mg based ferrite, a Ba based ferrite, an Li based ferrite, or the like.

The magnetic metal powder may contain at least one selected from the group consisting of Fe, Si, Cr, Al, and Ni. For example, the magnetic metal powder may contain Fe—Si—B—Cr based amorphous metal particles, but is not limited thereto.

The magnetic metal powder may have a particle diameter of 0.1 μm to 30 μm and may be included in a form in which magnetic metal powder particles are dispersed in a thermoplastic resin such as an epoxy resin, polyimide, or the like.

The internal electrodes41and42disposed within the magnetic body10may be formed as spiral shaped coils.

The first internal electrode41having a coil shape may be formed on a first surface of the substrate30disposed within the magnetic body10, and the second internal electrode42having a coil shape may be formed on a second surface opposing the first surface of the substrate30. The first and second internal electrodes41and42may be electrically connected to each other through vias (not shown) formed in the substrate30.

The first and second internal electrodes41and42may be formed by an electroplating method.

The internal electrodes and vias (not shown) may contain a metal having excellent electrical conductivity, such as silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt), or alloys thereof.

The internal electrodes41and42may be coated with an insulating layer50. The insulating layer50may be formed by an exposure or development process such as screen printing or photoresist (PR), or a spray coating process, commonly known in the art.

The insulating layer50may contain one or more materials selected from the group of epoxy, polyimide, and a liquid crystalline polymer (LCP), but is not limited thereto. The internal electrodes41and42may be coated with the insulating layer50and may not be in direct contact with a magnetic material forming the magnetic body10.

The substrate30may be formed as, for example, a polypropylene glycol (PPG) substrate, a ferrite substrate, a metallic soft-magnetic material, or the like. A through hole may be formed to penetrate through a central portion of the substrate30and may be filled with a magnetic material to form a core part55. In accordance with the formation of the core part55filled with a magnetic material, inductance Ls may be improved.

One end portion of the first internal electrode41formed on one surface of the substrate30may be exposed to one end surface of the magnetic body10in the length direction (L), and one end portion of the second internal electrode42formed on the other surface of the substrate30may be exposed to the other end surface of the magnetic body10in the length direction (L).

The internal electrodes41and42exposed to the both end surfaces of the magnetic body10in the length direction (L) may be connected to the first and second external electrodes81and82to be electrically connected thereto.

The first and second external electrodes81and82may contain a metal having excellent electrical conductivity, such as nickel (Ni), copper (Cu), tin (Sn), silver (Ag), or the like, alone or in combination.

EXAMPLES

Tables 1 and 2 show comparative results obtained by observing process defects in inductors (Inventive Examples) according to an exemplary embodiment of the present inventive concept and in inductors (Comparative Examples) not in compliance with the exemplary embodiment of the present inventive concept, and measuring capacity degrees of the inductors. Table 1 was obtained by observing the occurrence of process defects depending on a distance from an upper surface of a magnetic body to a substrate and a distance from the upper surface of the magnetic body to an internal electrode. Table 2 was obtained by observing the occurrence of process defects depending on a distance from a lower surface of the magnetic body to the substrate and a distance from the lower surface of the magnetic body to an internal electrode.

In Tables 1 and 2, inductors each including a magnetic body having a thickness of 0.6 mm were used in the Inventive Examples and the Comparative Examples. In the examples of Table 1, a distance from the lower surface of the magnetic body to the internal electrode exposed to one end surface of the magnetic body was set to 150 μm or more. In the examples of Table 2, a distance from the upper surface of the magnetic body to the internal electrode exposed to one end surface of the magnetic body was set to 100 μm or more.

In Tables 1 and 2, the Inventive Examples were manufactured in such a manner that the substrate thereof was inclined, and distances from the upper and lower surfaces of the magnetic body to the substrate exposed to end surfaces of the magnetic body were set to 60 μm or more.

In Table 1, Comparative Example 1 was manufactured by not inclining the substrate, while Comparative Examples 2 to 9 were manufactured by inclining the substrate. In Table 2, Comparative Example 10 was manufactured by not inclining the substrate, while Comparative Examples 11 to 18 were manufactured by inclining the substrate.

The occurrence of process defects was confirmed by cutting the inductors according to the inventive and comparative examples to observe the occurrence of cracks, delamination, edge tearing, and the like, through scanning electron microscope (SEM) measurement.

As shown in Table 1, process defects did not occur when the substrate was inclined, the distance from the upper surface of the magnetic body to the substrate was 60 μm or more, and the distance from the upper surface of the magnetic body to the internal electrode was 100 μm or more.

As shown in Table 2, process defects did not occur when the substrate was inclined, the distance from the lower surface of the magnetic body to the substrate was 60 μm or more, and the distance from the lower surface of the magnetic body to the internal electrode was 150 μm or more.

As set forth above, according to embodiments of the present inventive concept, an inductor having high capacity characteristics and allowing for reliability improvements in a manufacturing process by preventing defects due to delamination, cracks, and the like, may be provided.