Inductor and method for manufacturing the same

Abstract

To provide an inductor in which alignment of a coil having a high aspect ratio is improved, by eliminating the manufacturing process limit, and to provide a manufacturing method thereof.SOLUTION: An inductor includes a body having a support member, a coil, and a sealing material, and an external electrode placed on the external surface of the body. The coil in the body is constituted so that multiple coil patterns continue, the coil pattern includes first and second coil layers, and the sealing material is placed to extend toward the support member between the first coil layer. A manufacturing method of inductor for manufacturing the above-mentioned inductor applies a step of arranging to coat one surface of the support member entirely, when forming the first coil layer placed below the second coil layer, and removing a part of the first coil layer after forming the second coil layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an inductor and a method for manufacturing the same, and more particularly to a thin-film power inductor and a method for manufacturing the same, which are advantageous for the required characteristics of small size and high capacitance.

Background Art

[0002] With the development of IT technology, the miniaturization and thinning of devices have been accelerating, and accordingly, the market demand for small and thin elements has been increasing.

[0003] In order to cope with such a technological trend, in Patent Document 1 below, efforts have been made to provide an inductor having a coil that is uniform and has a high aspect ratio by providing a power inductor including a substrate having via holes and coils disposed on both surfaces of the substrate and electrically connected through the via holes of the substrate. However, due to the limitations of the manufacturing process, there is still a limit in forming a coil that is uniform and has a high aspect ratio.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One of the various problems to be solved by the present invention is to provide an inductor and a method for manufacturing the same, which eliminate the above limitations and improve the alignment of a coil having a high aspect ratio.

Means for Solving the Problems

[0006] An inductor according to an example of the present invention includes a main body including a support member, a coil supported by the support member, and a sealing material that seals the support member and the coil, and an external electrode disposed on an outer surface of the main body. The coil includes a plurality of coil patterns, and each coil pattern includes a first coil layer and a second coil layer disposed on the first coil layer. The sealing material includes magnetic powder and is filled in a space between adjacent coil patterns, and the sealing material is disposed so as to extend in a direction toward the support member between the first coil layers.

[0007] A method for manufacturing an inductor according to another example of the present invention includes the steps of preparing a support member including via holes, forming a conductive metal layer on at least one surface of the support member and in the via holes, peeling the conductive metal layer on the one surface of the support member, forming a first metal layer on the one surface of the support member, disposing an insulating material on the first metal layer, patterning the insulating material so as to have a plurality of partition patterns, forming a second metal layer in a space between the partition patterns, simultaneously removing at least a part of the insulating material and the first metal layer disposed thereunder, coating an insulating layer so as to entirely surround exposed surfaces of the second metal layer and the first metal layer disposed thereunder, filling a sealing material so as to seal the first and second metal layers, and forming an external electrode on an outside of the sealing material.

Advantages of the Invention

[0008] As one of various effects of the present invention, when constructing a coil having a high aspect ratio, by improving the alignment of the coils, it is possible to increase the production of inductors with increased capacitance and reduced size.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3a

Figure 3b

Figure 3c

Figure 3d

Figure 4a

Figure 4b

Figure 4c

Figure 4d

Figure 4e

Figure 4f

Figure 4g

Figure 4h

Figure 4i

Embodiments for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Also, the embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field. Therefore, for clearer explanation, elements such as the shape and size in the drawings may be enlarged or reduced (or emphasized or simplified).

[0011] Note that, for the purpose of clearly explaining the present invention, parts not related to the explanation are omitted in the drawings, the thickness is enlarged to clearly show various layers and regions, and components having the same function within the scope of the same concept are described using the same reference numerals.

[0012] Furthermore, throughout the specification, stating that a certain component "includes" does not mean excluding other components, but rather means that other components can be further included, unless otherwise stated to the contrary.

[0013] Hereinafter, an inductor according to an example of the present invention and a method for manufacturing the same will be described, but the present invention is not necessarily limited thereto.

[0014] Inductor FIG. 1 is a schematic perspective view of an inductor according to an example of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line I-I' of FIG. 1.

[0015] Referring to FIGS. 1 and 2, an inductor 100 according to an example of the present invention includes a main body 1 and first and second external electrodes 21 and 22 disposed on the outer surface of the main body.

[0016] First, the first and second external electrodes 21 and 22 will be described. The first and second external electrodes contain a metal with excellent electrical conductivity, and for example, can include nickel (Ni), copper (Cu), tin (Sn), silver (Ag), etc. alone or alloys thereof. The method of forming the first and second external electrodes and their specific shapes are not limited. For example, they can be configured in the shape of the letter C by the dipping method.

[0017] Next, the main body 1 forms the appearance of the inductor and includes an upper surface and a lower surface that face each other in the thickness (T) direction, a first surface and a second surface that face each other in the length (L) direction, and a third surface and a fourth surface that face each other in the width (W) direction. It can be substantially a hexahedron, but is not limited thereto. Here, the length extending in the thickness direction is referred to as "thickness" or "height".

[0018] The main body 1 includes a support member 11, a coil 12 supported by the support member, and a sealing material 13 that seals the support member and the coil.

[0019] First, the sealing material 13 contains magnetic particles. The magnetic particles may be, for example, one or more selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), aluminum (Al), and nickel (Ni), or may be ferrite. Also, the sealing material can be composed of a magnetic particle-resin composite in which magnetic particles are filled in a resin.

[0020] Next, the support member 11 will be described. The support member is for making the coil thinner and easier to form. The support member can be an insulating base material made of an insulating resin. At this time, as the insulating resin, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as polyimide, or a resin impregnated with a reinforcing material such as glass fiber or inorganic filler, for example, prepreg, ABF (Ajinomoto Build-up Film), FR-4, BT (Bismaleimide Triazine) resin, PID (Photo Imageable Dielectric) resin, etc. can be used. When the support member contains glass fiber, it can have better rigidity.

[0021] A through hole H can be formed in the central portion of the support member, and the through hole can be filled with a material having magnetic properties to form a core portion.

[0022] Also, the support member can include a through via 11a penetrating from the upper surface to the lower surface of the support member. The through via 11a can be formed by processing a via hole in the support member and then filling the via hole with a conductive material.

[0023] On the other hand, a coil 12 is supported on the upper surface and the lower surface of the support member, and the coil includes a plurality of coil patterns 121. The coil pattern 121 includes a first coil layer 121a and a second coil layer 121b disposed on the first coil layer.

[0024] The above-described first coil layer 121a is a layer that functions as a seed layer with respect to the second coil layer. Usually, a seed layer has a structure in which the entire outer surface is covered by a plating layer disposed thereon. However, in the first coil layer of the coil pattern of the inductor of the present invention, only the upper surface thereof is entirely covered by the second coil layer disposed thereon, and at least a part of the side surface thereof is not covered by the second coil layer disposed thereon, but is covered by a sealing material 13 having magnetic properties. Needless to say, an insulating layer may be further coated on the coil pattern for insulation between the magnetic particles in the sealing material and the coil pattern. Since the upper surface of the first coil layer is configured to contact the lower surface of the second coil layer and the side surface of the first coil layer is not covered by the second coil layer, the width of the upper surface of the first coil layer is substantially the same as the width of the lower surface of the second coil layer.

[0025] Also, referring to FIG. 2, the average distance between adjacent first coil layers is substantially the same as the average distance between adjacent second coil layers. This means that the aspect ratio of the coil pattern composed of the first and second coil layers can be sufficiently increased. Usually, the average distance between seed layers arranged to contact the support member is larger than the average distance between plating layers disposed thereon. In this case, however, it is very difficult to maintain the distance between the plating layers at a uniform and constant level or higher. Therefore, there is a limit to growing the plating layer in the thickness direction, and the aspect ratio cannot be sufficiently increased.

[0026] Different from the prior art, since the average distance between the first coil layers is substantially the same as the average distance between the second coil layers, the aspect ratio of the coil pattern can be increased uniformly and stably. Specifically, the aspect ratio of the above-described coil can be 2 or more and 20 or less. When the aspect ratio is less than 2, the effect of improving the electrical characteristics of the coil is not significant. When the aspect ratio is greater than 20, there may be engineering difficulties such as collapse of the coil pattern or warping of the support member during the formation process of the coil pattern.

[0027] On the one hand, the first coil layer and the second coil layer may be made of the same material as each other, but it is more preferable that they are made of different materials from each other. As materials applicable to the first and second coil layers, one or more of copper (Cu), titanium (Ti), nickel (Ni), tin (Sn), molybdenum (Mo), and aluminum (Al) can be included. In particular, it is preferable that the first coil layer contains titanium (Ti) or nickel (Ni), and the second coil layer disposed thereon contains copper (Cu). This is an applicable embodiment in consideration of all of electrical conductivity, economy, and ease of process. Therefore, the first coil layer and the through via in contact with at least a part of the first coil layer can be made of different materials from each other. Similarly, the first coil layer can contain titanium (Ti) or nickel (Ni), and the through via can contain copper (Cu). In this case, an interface exists between the first coil layer and the through via, and they are arranged discontinuously with respect to each other. For reference, in the structure of a normal inductor, a through via and a seed layer connected to the through via are formed simultaneously, and it is impossible to distinguish between the components, and they are continuously configured with respect to each other. However, in the inductor of the present invention, since the through via and the first coil layer thereon are formed by different processes, it is possible to distinguish between the components, and they are configured discontinuously with respect to each other.

[0028] The surface of the coil pattern composed of the first and second coil layers is coated with an insulating layer 14, and the insulating layer 14 is configured according to the shape of the outer surface of the coil pattern disposed thereunder. The fact that the insulating layer is configured according to the shape of the outer surface of the coil pattern means that the insulating layer is configured to be uniform and thin. The insulating layer 14 can be used without limitation as long as it is a material capable of forming a uniform polymer insulating film. For example, it can include poly(p-xylylene), epoxy resin, polyimide resin, phenoxy resin, polysulfone resin, and polycarbonate resin, or a resin of a perylene-based compound. In particular, when a perylene-based compound is included, it is preferable because a uniform and stable insulating layer can be realized by utilizing a chemical vapor deposition method.

[0029] Next, an embodiment of a manufacturing method for manufacturing the above-described inductor will be described, and the structure of the inductor and the technical effects derivable from the structure will be described in more detail.

[0030] Manufacturing Method of Inductor Before describing the manufacturing method of the inductor of the present invention, a conventional manufacturing method for manufacturing a normal thin-film inductor will be described with reference to FIGS. 3a to 3d.

[0031] First, FIG. 3a shows preparing a support member 5 in which via holes 51 are formed and forming a copper seed layer 61 on at least a part of the upper surface of the support member. In this case, it can be seen that the copper seed layer 61 is configured to continuously extend to the inside of the via holes of the support member.

[0032] FIG. 3b shows further forming a copper plating layer 62 on the copper seed layer 61. In order to increase the aspect ratio, the copper plating layer is generally formed by anisotropic plating, but there is a problem that the cross-sectional shape of the copper plating layer is not uniform and is formed to have a generally mushroom-like shape as a whole.

[0033] Next, referring to FIG. 3c, after forming the insulating layer 7 so as to insulate the surface of the coil 6 composed of the copper seed layer and the copper plating layer, the coil and the support member are encapsulated with the encapsulant 8 having magnetic properties.

[0034] FIG. 3d shows that after performing a finishing process on the support member and the coil encapsulated with the encapsulant, external electrodes 91 and 92 are formed.

[0035] Thus, when forming a thin-film inductor by a normal technique, since the coil does not grow uniformly, there is a limit to the increase in the aspect ratio of the coil.

[0036] The manufacturing method of an inductor according to another example of the present invention to be described next proposes a manufacturing method capable of solving the above problems, and enables the aspect ratio of the coil to be significantly increased to a level of 2 or more and 20 or less. Further, in the step of forming the coil plating layer, which particularly plays a decisive role in improving the aspect ratio of the coil, problems that may occur due to the misalignment between the position of the coil seed layer disposed under the coil plating layer and the position where the coil plating layer is formed can be prevented in advance. The explanation of the above alignment will be described in detail with reference to FIG. 4e described later.

[0037] FIGS. 4a to 4i are diagrams for explaining a manufacturing method of an inductor according to another example of the present invention. At this time, for the sake of convenience of explanation, the same reference numerals are used for the components corresponding to the components in FIGS. 3a to 3d.

[0038] Referring to FIG. 4a, after preparing the support member 5 in which the via hole 51 is formed, a copper seed layer for forming the through via 52 formed by filling the via hole is formed. The copper seed layer means a conductive metal layer formed on the upper surface of the support member and in the via hole. In this case, it goes without saying that the material of the conductive metal layer is not limited to copper only.

[0039] Referring to FIG. 4b, except for the vias in the copper seed layer formed in FIG. 4a, the conductive metal layer disposed on the upper surface of the support member is peeled off. Next, a first metal layer 61 is formed at the position where the conductive metal layer has been peeled off. The method of forming the first metal layer is not limited, and any method capable of forming a uniform and thin metal layer may be used. For example, sputtering, electroless copper plating, Chemical Vapor Deposition (CVD), etc. can be used. The thickness of the first plating layer can be appropriately configured by those skilled in the art according to design changes. For example, it can be 50 nm or more and 1 μm or less, but is not particularly limited. The material of the first metal layer is not particularly limited as long as it is a material having electrical conductivity. Considering the step of removing a part of the first metal layer described later, in order to minimize the remaining first metal layer, it is preferably mainly composed of titanium (Ti) or nickel (Ni).

[0040] Next, FIG. 4c shows disposing an insulating material R on the first metal layer. At this time, the insulating material contains an epoxy-based compound. For example, as a permanent type photosensitive insulating substance, it can contain a photosensitive substance mainly composed of a bisphenol-based epoxy resin. Needless to say, the insulating material can have a structure in which a plurality of insulating sheets are laminated.

[0041] FIG. 4d shows the step of patterning the insulating material so that it has a plurality of partition patterns. The patterning method is not limited, such as printing method, photolithography method, etc. For example, a desired partition pattern can be formed by performing selective exposure and development on the insulating material. At this time, the aspect ratio of the partition pattern can be configured to be very high at a level of approximately 100. This means that the thickness is significantly higher compared to the width of the partition pattern, enabling the miniaturization of the fine wire width of the coil described later.

[0042] Figure 4e shows the step of forming the second plating layer 62 between the partition patterns formed in Figure 4d. At this time, since the first plating layer serves as a seed layer for the second plating layer, the alignment between the first plating layer and the second plating layer becomes an important issue. In the case of the method for manufacturing an inductor according to the present invention, since the first plating layer is continuously disposed on the upper surface of the support member, there are not many restrictions on the opening of the partition pattern and the formation position of the second plating layer. As a result, it becomes easy to increase the fine line width between the coil patterns 6 composed of the first and second plating layers. In Figure 4e, when the upper surface of the second plating layer is located higher than the upper surface of the partition pattern in contact with its side surface, a polishing process may be required to prevent a short circuit between adjacent second plating layers. As the polishing process, mechanical polishing or chemical polishing can be applied, and those skilled in the art can appropriately change the design according to the design requirements. On the other hand, when the upper surface of the second plating layer is located lower than the upper surface of the partition pattern in contact with its side surface and is underplated, the polishing process can be omitted.

[0043] Figure 4f shows simultaneously removing the insulating material and the first plating layer disposed under the insulating material. At this time, among the first plating layers, the first plating layer disposed under the second plating layer is not removed. As a method for removing the insulating material and the first plating layer, for example, Laser Trimming can be used, but it is not limited thereto.

[0044] Next, Figure 4g shows cleaning the residue remaining after removing the insulating material in Figure 4f and the first plating layer disposed under the insulating material. The coil pattern composed of the second plating layer and the first plating layer disposed under it has a shape corresponding to the opening of the partition pattern of the insulating material. Therefore, the cross-sections of the first and second plating layers constitute substantially the same cross-section without being changed along the thickness direction. Thereby, the aspect ratio of the coil pattern is greatly improved, and the overall size of the inductor is also reduced.

[0045] FIG. 4h shows the step of coating the outer surface of the coil pattern 6 composed of the first and second plating layers with the polymer resin 7. For example, CVD or sputtering can be applied, but it is not specifically limited. The polymer resin is, for example, a perylene resin, which serves to prevent short circuits between adjacent coil patterns.

[0046] FIG. 4i shows that, as a finishing process, the coil and the support member are sealed with a sealing material 8 having magnetic properties, and after performing a dicing process on the support member and the coil sealed with the sealing material, external electrodes 91 and 92 are formed.

[0047] Except for the above description, the description overlapping with the features of the inductor according to an example of the present invention described above is omitted here.

[0048] When using the above inductor and the method for manufacturing the inductor, the aspect ratio of the coil can be significantly increased, and the miniaturization of the chip size can be realized by achieving a fine line width between the coil patterns. In particular, by significantly reducing the sensitivity of the alignment between the opening of the insulating material having the partition pattern required to form a uniform coil pattern and the seed layer required to fill the coil pattern between the openings, the problem of alignment deviation can be completely eliminated. Thereby, the manufacturing yield of the inductor can be increased, and it can also be expected to secure cost competitiveness due to the increase in the manufacturing yield.

[0049] As described above in detail for the embodiments of the present invention, it is obvious to those skilled in the art that the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope not departing from the technical idea of the present invention described in the claims.

[0050] On the one hand, the expressions "one example" or "another example" used in the present invention do not mean the same embodiment, but are provided to emphasize and explain different unique features respectively. However, the above-presented one example does not exclude being combined with the features of another example. For example, even if a matter described in a specific one example is not described in another example, it can be understood as an explanation related to another example as long as there is no explanation contrary to or conflicting with that matter in another example.

[0051] In addition, the terms used in the present invention are only for the purpose of explaining one example and are not intended to limit the present invention. At this time, the singular expression includes the plural unless the context clearly indicates a different meaning.

Explanation of Reference Numerals

[0052] 100 Inductor 1 Body 11 Support Member 12 Coil 13 Sealing Material 21, 22 First and Second External Electrodes

Claims

1. a main body, a support member disposed inside the main body, and a coil supported by the support member; an external electrode disposed on a side surface of the support member on an external surface of the body, the coil includes a plurality of coil patterns, each of the plurality of coil patterns including a first coil layer and a second coil layer disposed on the first coil layer; The body has a composite body in which magnetic particles are filled in a resin, the surfaces of the coil patterns are coated with an insulating layer containing perylene; The insulating layers are not formed on the support member between adjacent insulating layers. Inductor.

2. a main body, a support member disposed inside the main body, and a coil supported by the support member; an external electrode disposed on a side surface of the support member on an external surface of the body, the coil includes a plurality of coil patterns, each of the plurality of coil patterns including a first coil layer and a second coil layer disposed on the first coil layer; The body has a composite body in which magnetic particles are filled in a resin, the surfaces of the coil patterns are coated with an insulating layer containing perylene; When the main body is viewed in a thickness direction of the main body, the outermost coil pattern and the insulating layer coated on a surface of the outermost coil pattern are in contact with the external electrode. Inductor.

3. a main body, a support member disposed inside the main body, and a coil supported by the support member; an external electrode disposed on a side surface of the support member on an external surface of the body, the coil includes a plurality of coil patterns, each of the plurality of coil patterns includes a first coil layer and a second coil layer disposed on the first coil layer and spaced apart from the support member; one of the first coil layers is disposed on one surface of the support member, and one of the second coil layers is disposed on the one of the first coil layers and spaced apart from the support member; another first coil layer is disposed on the other surface of the support member, and another second coil layer is disposed on the other first coil layer and spaced apart from the support member; The body has a composite body in which magnetic particles are filled in a resin, the surfaces of the coil patterns are coated with an insulating layer containing perylene; the main body includes a sealing material that is the composite that seals the support member and the coil; Another side surface of the support member different from the side surface is in contact with the sealing material. Inductor.

4. The inductor according to claim 1 , wherein the insulating layer is configured according to a shape of an outer surface of a coil pattern disposed thereunder.

5. The inductor according to claim 1 , wherein the body is filled in a space between adjacent insulating layers.

6. The inductor of claim 1 , wherein a width of an upper surface of the first coil layer is the same as a width of a lower surface of the second coil layer.

7. The inductor of claim 1 , wherein the aspect ratio of the coil is between 2 and 20.

8. The inductor of claim 1 , wherein an average distance between adjacent first coil layers is the same as an average distance between adjacent second coil layers.

9. The inductor of claim 1 , wherein the first coil layer and the second coil layer are made of different materials.

10. the first coil layer includes one or more of titanium (Ti), nickel (Ni), and molybdenum (Mo); the second coil layer comprises copper (Cu); The inductor of claim 9.

11. An inductor as described in any one of claims 1 to 10, wherein the support member includes a via hole, the via hole is filled with an electrically conductive material to form a through via, and the through via is arranged discontinuously with the lower surface of the first coil layer arranged above the through via.

12. The inductor of claim 11 , wherein the through via material is different from the material of the first coil layer.

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