Patent ID: 12205745

DETAILED DESCRIPTION

The terms used in the description of the present disclosure are used to describe a specific embodiment, and are not intended to limit the present disclosure. A singular term includes a plural form unless otherwise indicated. The terms “include,” “comprise,” “is configured to,” etc. of the description of the present disclosure are used to indicate the presence of features, numbers, steps, operations, elements, parts, or combination thereof, and do not exclude the possibilities of combination or addition of one or more additional features, numbers, steps, operations, elements, parts, or combination thereof. Also, the terms “disposed on,” “positioned on,” and the like, may indicate that an element is positioned on or beneath an object, and does not necessarily mean that the element is positioned above the object with reference to a gravity direction.

The term “coupled to,” “combined to,” and the like, may not only indicate that elements are directly and physically in contact with each other, but also include the configuration in which another element is interposed between the elements such that the elements are also in contact with the other component.

Sizes and thicknesses of elements illustrated in the drawings are indicated as examples for ease of description, and the present disclosure are not limited thereto.

In the drawings, an L direction is a first direction or a length (longitudinal) direction, a W direction is a second direction or a width direction, a T direction is a third direction or a thickness direction.

Hereinafter, a coil component according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. Referring to the accompanying drawings, the same or corresponding components may be denoted by the same reference numerals, and overlapped descriptions will be omitted.

In electronic devices, various types of electronic components may be used, and various types of coil components may be used between the electronic components to remove noise, or for other purposes.

In other words, in electronic devices, a coil component may be used as a power inductor, a high frequency (HF) inductor, a general bead, a high frequency (GHz) bead, a common mode filter, and the like.

FIG.1is a schematic view illustrating a coil component according to an exemplary embodiment of the present disclosure.FIG.2is a cross-sectional view taken along line I-I′ ofFIG.1.FIG.3is a cross-sectional view taken along line II-II′ ofFIG.1.FIG.4is an enlarged view of portion A ofFIG.1.FIG.5is a view illustrating a modification of portion A ofFIG.1.

Referring toFIGS.1to5, a coil component1000according to exemplary embodiments of the present disclosure may include a body100, an insulating substrate200, a coil portion300, and external electrodes400and500, and may further include an insulating film600.

According to an exemplary embodiment of the present disclosure, the body100may form an exterior of the coil component1000, and the insulating substrate200and the coil portion300may be embedded therein.

The body100may be formed to have a hexahedral shape overall.

Referring toFIGS.1to3, the body100may include a first surface101and a second surface102facing each other in a longitudinal direction L, a third surface103and a fourth surface104facing each other in a width direction W, and a fifth surface105and a sixth surface106facing each other in a thickness direction T. Each of the first to fourth surfaces101,102,103, and104of the body100may correspond to wall surfaces of the body100connecting the fifth surface105and the sixth surface106of the body100. Hereinafter, both end surfaces of the body100may refer to the first surface101and the second surface102of the body100, both side surfaces of the body100may refer to the third surface103and the fourth surface104of the body100, one surface of the body100may refer to the sixth surface106of the body100, and the other surface of the body100may refer to the fifth surface105of the body100. Further, hereinafter, an upper surface and a lower surface of the body100may refer to the fifth surface105and the sixth surface106of the body100, respectively, based on the directions ofFIGS.1to3.

The body100of the coil component1000according to an exemplary embodiment of the present disclosure may be formed such that the external electrodes400and500to be described later have a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.65 mm, but is not limited thereto. Alternatively, the body100of the coil component1000according to an exemplary embodiment of the present disclosure may be formed such that the external electrodes400and500to be described later have a length of 2.0 mm, a width of 1.6 mm, and a thickness of 0.55 mm. Still alternatively, the body100of the coil component1000according to an exemplary embodiment of the present disclosure may be formed such that the external electrodes400and500to be described later have a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.55 mm. Still alternatively, the body100of the coil component1000according to an exemplary embodiment of the present disclosure may be formed such that the external electrodes400and500to be described later have a length of 1.2 mm, a width of 1.0 mm, and a thickness of 0.55 mm. Since the above-described sizes of the coil component1000are merely illustrative, cases in which a size of the body100of the coil component1000are smaller than the above-mentioned dimensions may be not excluded from the scope of the present disclosure.

The body100may include a magnetic powder particle (P) and an insulating resin (R). Specifically, the body100may be formed by stacking at least one magnetic composite sheet including the insulating resin (R) and the magnetic powder particle (P) dispersed in the insulating resin (R), and then curing the magnetic composite sheet. The body100may have a structure other than the structure in which the magnetic powder particle (P) may be dispersed in the insulating resin (R). For example, the body100may be made of a magnetic material such as ferrite.

The magnetic powder particle (P) may be, for example, a ferrite powder particle or a metal magnetic powder particle.

Examples of the ferrite powder particle may include at least one or more of spinel type ferrites such as Mg—Zn-based ferrite, Mn—Zn-based ferrite, Mn—Mg-based ferrite, Cu—Zn-based ferrite, Mg—Mn—Sr-based ferrite, Ni—Zn-based ferrite, and the like, hexagonal ferrites such as Ba—Zn-based ferrite, Ba—Mg-based ferrite, Ba—Ni-based ferrite, Ba—Co-based ferrite, Ba—Ni—Co-based ferrite, and the like, garnet type ferrites such as Y-based ferrite, and the like, and Li-based ferrites.

The metal magnetic powder particle may include one or more selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), cobalt (Co), molybdenum (Mo), aluminum (Al), niobium (Nb), copper (Cu), and nickel (Ni). For example, the metal magnetic powder particle may be at least one or more of a pure iron powder, a Fe—Si-based alloy powder, a Fe—Si—Al-based alloy powder, a Fe—Ni-based alloy powder, a Fe—Ni—Mo-based alloy powder, a Fe—Ni—Mo—Cu-based alloy powder, a Fe—Co-based alloy powder, a Fe—Ni—Co-based alloy powder, a Fe—Cr-based alloy powder, a Fe—Cr—Si-based alloy powder, a Fe—Si—Cu—Nb-based alloy powder, a Fe—Ni—Cr-based alloy powder, and a Fe—Cr—Al-based alloy powder.

The metallic magnetic powder particle may be amorphous or crystalline. For example, the metal magnetic powder particle may be a Fe—Si—B—Cr-based amorphous alloy powder, but is not limited thereto.

The ferrite powder and the metal magnetic powder particle may have an average diameter of about 0.1 μm to 30 μm, respectively, but are not limited thereto.

The body100may include two or more types of magnetic powder particles (P) dispersed in an insulating resin (R). In this case, the term “different types of magnetic powder particle (P)” means that the magnetic powder particles (P) dispersed in the insulating resin (R) are distinguished from each other by diameter, composition, crystallinity, and a shape. For example, the body100may include two or more magnetic powder particles (P) of different diameters.

The insulating resin (R) may include an epoxy, a polyimide, a liquid crystal polymer, or the like, in a single form or in combined forms, but is not limited thereto.

The body100may include a core110passing through the coil portion300to be described later. The core110may be formed by filling at least a portion of the magnetic composite sheet with through-holes formed in the insulating substrate200in operations of stacking and curing the magnetic composite sheet, but is not limited thereto.

The insulating substrate200may be embedded in the body100. The insulating substrate200may support the coil portion300to be described later.

The insulating substrate200may include an insulating material, for example, a thermosetting insulating resin such as an epoxy resin, a thermoplastic insulating resin such as polyimide, or a photosensitive insulating resin, or the insulating substrate200may include an insulating material in which a reinforcing material such as a glass fiber or an inorganic filler is impregnated with an insulating resin. For example, the insulating substrate200may include an insulating material such as prepreg, Ajinomoto Build-up Film (ABF), FR-4, a bismaleimide triazine (BT) film, a photoimageable dielectric (PID) film, and the like, but are not limited thereto.

As the inorganic filler, at least one or more selected from a group consisting of silica (SiO2), alumina (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc, mud, a mica powder, aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), magnesium carbonate (MgCO3), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO3), barium titanate (BaTiO3), and calcium zirconate (CaZrO3) may be used.

When the insulating substrate200includes an insulating material including a reinforcing material, the insulating substrate200may provide better rigidity. When the insulating substrate200is formed of an insulating material not containing glass fibers, the insulating substrate200may be advantageous for reducing a thickness of the overall coil portion300. When the insulating substrate200includes an insulating material containing a photosensitive insulating resin, the number of processes for forming the coil portion300may be reduced. Therefore, it may be advantageous in reducing production costs, and a fine via may be formed.

According to an exemplary embodiment of the present disclosure, the insulating substrate200may include an insulating resin210and a glass cloth220impregnated with the insulating resin210. As a non-limiting example, the insulating substrate200may include a copper clad laminate (CCL). The glass cloth220may be a plurality of glass fibers are woven.

The glass cloth may be formed as a plurality of layers. When the glass cloth is formed as a plurality of layers, the rigidity of the insulating substrate200may be improved. Also, even when the insulating substrate200is damaged in an operation of removing first conductive layers311aand312ato be described later, a shape of the insulating substrate200may be maintained and the defect rate may be reduced.

A thickness (T1) of the insulating substrate200may be greater than 20 μm but less than 40 μm, and more preferably 25 μm or more and 35 μm or less. When the thickness (T1) of the insulating substrate200is 20 μm or less, it may be difficult to secure the rigidity of the insulating substrate200, to support the coil portion300to be described later in the manufacturing process. When the thickness (T1) of the insulating substrate200is 40 μm or more, it may be disadvantageous to make the coil portions thinner, and it may be disadvantageous in realizing high capacity inductance, since a volume occupied by the insulating substrate200in the body100of the same volume increases.

The coil portion300may include coil patterns311and312, having a planar spiral shape, arranged on the insulating substrate200, and may be embedded in the body100, to manifest the characteristics of the coil component. For example, when the coil component1000according to an exemplary embodiment of the present disclosure is used as a power inductor, the coil portion300may function to stabilize the power supply of an electronic device by storing an electric field as a magnetic field and maintaining an output voltage.

The coil portion300may include the coil patterns311and312, and a via320. Specifically, based on the directions ofFIGS.1,2, and3, a first coil pattern311may be disposed on a lower surface of the insulating substrate200facing the sixth surface106of the body100, and a second coil pattern312may be disposed on an upper surface of the insulating substrate200. The via320may pass through the insulating substrate200, and may be in contact with and connected to the first coil pattern311and the second coil pattern312, respectively. In this configuration, the coil portion300may function as a single coil which forms one or more turns about the core110overall.

Each of the first coil pattern311and the second coil pattern312may be in a planar spiral shape having at least one turn formed about the core110. For example, based on the direction ofFIG.2, the first coil pattern311may form at least one turn about the core110on the lower surface of the insulating substrate200.

End portions of the first and second coil patterns311and312may be connected to the first and second external electrodes400and500, respectively, which will be described later. For example, the end portion of the first coil pattern311may be connected to the first external electrode400, and the end portion of the second coil pattern312may be connected to the second external electrode500.

For example, the end portion of the first coil pattern311may be exposed from the first surface101of the body100, and the end portion of the second coil pattern312may be exposed from the second surface102of the body100, to be in contact with and connected to the first and second external electrodes400and500disposed on the first and second surfaces101and102of the body100, respectively.

Each of the first and second coil patterns311and312may include first conductive layers311aand312aformed to contact the insulating substrate200, and second conductive layers311band312bdisposed on the first conductive layers311aand312a. Based on the directions ofFIGS.4and5, the first coil pattern311may include a first conductive layer311aformed to contact the lower surface of the insulating substrate200, and a second conductive layer311bdisposed on the first conductive layer311a. Based on the directions ofFIGS.4and5, the second coil pattern312may include a first conductive layer312aformed to contact the upper surface of the insulating substrate200, and a second conductive layer312bdisposed on the first conductive layer312a.

The first conductive layers311aand312amay be seed layers for forming the second conductive layers311band312bby an electrolytic plating process. The first conductive layers311aand312a, the seed layers of the second conductive layers311band312b, may be formed to be thinner than the second conductive layers311band312b. The first conductive layers311aand312amay be formed by a thin film process such as sputtering or an electroless plating process. When the first conductive layers311aand312aare formed by a thin film process such as sputtering, at least a portion of materials constituting the first conductive layers311aand312amay be passed through the insulating substrate200. It can be confirmed that a concentration of a metal material constituting the first conductive layers311aand312ain the insulating substrate200varies in the thickness direction T of the body100.

A thickness (T2) of the first conductive layers311aand312amay be 1.5 μm or more and 3 μm or less. When the thickness of the first conductive layers311aand312ais less than 1.5 μm, it may be difficult to realize the first conductive layers311aand312a. When the thickness of the first conductive layers311aand312ais greater than 3 μm, in removing the first conductive layers311aand312a, except for regions in which the second conductive layers311band312bare formed by a plating process, it may be advantageous that the first conductive layers311aand312aremain, or are etched away together with the second conductive layers311band312b, when being excessively etched.

Referring toFIG.4, the second conductive layers311band312bmay expose at least a portion of the side surfaces of the first conductive layers311aand312a. According to an exemplary embodiment of the present disclosure, a seed layer for forming the first conductive layers311aand312amay be formed on both side surfaces of the insulating substrate200, a plating resist for forming the second conductive layers311band312bmay be formed on the seed layer, the second conductive layers311band312bmay be formed by the electrolytic plating process, the plating resist may be removed, and the seed layer on which the second conductive layers311band312bare not formed may be selectively removed. Therefore, at least a portion of the side surfaces of the first conductive layers311aand312aformed by selectively removing the seed layer may be exposed without being covered by the second conductive layers311band312b. The seed layer may be formed by performing an electroless plating process or a sputtering process on the insulating substrate200. Alternatively, the seed layer may be a copper foil of a copper clad laminate (CCL). The plating resist may be formed by applying a material for forming the plating resist to the seed layer and then performing a photolithography process thereon. After performing the photolithography process, an opening may be formed in a region in which the second conductive layers311band312bare to be formed. The selective removal of the seed layer may be performed by a laser process or an etching process. In the case in which the seed layer is selectively removed by etching, the first conductive layers311aand312amay be formed in such a manner that the cross-sectional area thereof increases as the side surfaces thereof proceed in a downward direction.

Referring toFIG.5, the second conductive layers311band312bmay cover the first conductive layers311aand312a. In a different manner toFIG.4, the first conductive layers311aand312apatterned in a plane spiral shape may be respectively disposed on both side surfaces of the insulating substrate200, and the second conductive layers311band312bmay be disposed on the first conductive layers311aand312aby an electrolytic plating process. When the second conductive layers311band312bare formed by an anisotropic plating process, a plating resist may not be used, but is not limited thereto. When the second conductive layers311band312bare formed by an isotropic plating process, a plating resist for forming the second conductive layer may be used. An opening for exposing the first conductive layers311aand312amay be formed in the plating resist for forming the second conductive layer. A diameter of the opening may be larger than a line width of the first conductive layers311aand312a. Therefore, the second conductive layers311band312bfilling the opening may cover the first conductive layers311aand312a.

The via320may include at least one conductive layer. For example, when the via320is formed by an electrolytic plating process, the via320may include a seed layer formed on an inner wall of a via hole passing through the insulating substrate200, and an electrolytic plating layer filling the via hole formed with the seed layer. The seed layer of the via320may be formed integrally with the first conductive layers311aand312ain the same process as the first conductive layers311aand312a, and may form a boundary between the seed layer and each of the first conductive layers311aand312ain a process different from the first conductive layers311aand312a. According to an exemplary embodiment of the present disclosure, the seed layer of the via and the first conductive layers311aand312amay be formed in different processes to form a boundary therebetween.

When the line widths of the coil patterns311and312are excessively wide, a volume of the magnetic body in the body100may be reduced to adversely affect inductance. In a non-limiting example, an aspect ratio (AR) of the coil patterns311and312may be between 3:1 and 9:1.

Each of the coil patterns311and312and the via320may be formed of a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), chromium (Cr), or alloys thereof, but are not limited thereto. As a non-limiting example, when the first conductive layers311aand312aare formed in a sputtering process, and the second conductive layers311band312bare formed by an electrolytic plating process, the first conductive layers311aand312amay include at least one of molybdenum (Mo), chromium (Cr), and titanium (Ti), and the second conductive layers311band312bmay include copper (Cu). As another non-limiting example, when the first conductive layers311aand312aare formed by an electroless plating process, and the second conductive layers311band312bare formed by an electrolytic plating process, the first conductive layers311aand312a, and the second conductive layers311band312bmay include copper (Cu). In this case, a density of the copper (Cu) in the first conductive layers311aand312amay be lower than a density of the copper (Cu) in the second conductive layers311band312b.

The thickness (T1) of the insulating substrate200and the thickness (T2) of the first conductive layers311aand312asatisfy 10≤T1/T2≤20. This will be described later.

The external electrodes400and500may be disposed on surfaces of the body100, and may be connected to both end portions of the coil portion300, respectively. According to an exemplary embodiment of the present disclosure, both end portions of the coil portion300may be exposed from the first and second surfaces101and102of the body100, respectively. Therefore, the first external electrode400may be disposed on the first surface101and may be in contact with and connect to an end portion of the first coil pattern311exposed from the first surface101of the body100, and the second external electrode500may be disposed on the second surface102and may be in contact with and connect to an end portion of the second coil pattern312exposed from the second surface102of the body100.

The external electrodes400and500may have a single-layer structure or a multilayer structure. For example, the first external electrode400may include a first layer comprising copper, a second layer disposed on the first layer and comprising nickel (Ni), and a third layer disposed on the second layer and comprising tin (Sn). The first to third surfaces may be formed by an electrolytic plating process, but is not limited thereto. As another example, the first external electrode400may include a resin electrode including a conductive powder particle and a resin, and a plating layer formed by a plating process on the resin electrode.

The external electrodes400and500may be formed of a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof, but is not limited thereto.

The insulating film600may be formed on the insulating substrate200and the coil portion300. The insulating film600may be for insulating the coil portion300from the body100, and may include a known insulating material such as parylene, and the like. An insulating material included in the insulating film600may be any insulating material, and is not particularly limited thereto. The insulating film600may be formed using a vapor deposition process or the like, but not limited thereto, and may be formed using stacking an insulation film on both surfaces of the insulating substrate200. In the former case, the insulating film600may be formed in the form of a conformal film along the surfaces of the insulating substrate200and the coil portion300. In the latter case, the insulating film600may be formed to fill a space between neighboring turns of the coil patterns311and312. As described above, a plating resist may be formed on the insulating substrate200for forming the second conductive layers311band312b, and such a plating resist may be a permanent resist which may be not removed. In this case, the insulating film600may be a plating resist which may be a permanent resist. The insulating film600may be omitted, when the body100secures sufficient insulation resistance under operating conditions of the coil component1000according to an exemplary embodiment of the present disclosure.

In Table 1, in Experimental Examples 1 to 9 in which ratios of a thickness (T1) of an insulating substrate to a thickness (T2) of a first conductive layer were changed, it was evaluated whether the inductance was realized, the rigidity of the insulating substrate was secured, and whether the first conductive layer was capable of being implemented.

In Experimental Examples 1 to 9, coil portions were manufactured to have the same number of turns, the same line width, and the same thickness, and to make spaces between neighboring turns of the coil portions all equal. A body was manufactured such that a thickness of the coil component was 0.55 mm.

In Table 1 below, it was evaluated as passed that inductance capacity obtained from the simulation falls within ranges of 90% to 110% of the inductance capacity. In the case of the rigidity of the insulating substrate, the thickness of the insulating substrate was evaluated as the presence or absence of breakage (tearing) of the substrate due to flow of plating liquid in a plating bath. In the case of the first conductive layer, it was determined as passed or failed, based on the thickness at which phenomenon that a second conductive layer is not plated occurs. Further, since the lowest thickness of the first conductive layer capable of realizing the second conductive layer is 1.5 μm at the level of the current technique, it was evaluated as passed, based thereon.

TABLE 1InductanceRigidity ofPossibility ofT1T2Implemen-Insulatingimplementing First(μm)(μm)T1/T2tationSubstrateConductive Layer# 1401.526.7FailedPassedPassed# 240140FailedPassedFailed# 3400.580FailedPassedFailed# 430310PassedPassedPassed# 530215PassedPassedPassed# 6301.520PassedPassedPassed# 730130PassedPassedFailed# 8300.560PassedPassedFailed# 92036.7PassedFailedPassed

Referring to Table 1, each of Experimental Examples 4, 5, and 6 satisfying 10≤T1/T2≤20 passed evaluations for inductance implementation, rigidity of insulating substrate, and possibility of implementing the first conductive layer. However, each of Experimental Examples 1 to 3, and 7 to 9 failed to pass at least one evaluation for inductance implementation, rigidity of insulating substrate, and possibility of implementing the first conductive layer.

In the case of Experimental Example 9 in which the thickness (T1) of the insulating substrate was 20 μm, rigidity could not be secured in the manufacturing process. In the case of Experimental Examples 2, 3, 7, and 8 in which the thickness (T2) of the first conductive layer was less than 1.5 μm, it may be difficult to implement the first conductive layer.

According to the present disclosure, it is possible to implement high-capacity inductance and secure rigidity of a certain level of the insulating substrate while being low profile.

While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present disclosure as defined by the appended claims.