Coil component

Abstract

A coil component according to one aspect of the present invention comprises a body portion that includes a magnetic body, and a coil portion that is built into the body portion and has a coil conductor portion including a spiral portion provided in a spiral shape by being wound a plurality of turns around a winding axis following a first direction, wherein the outermost turn among the plurality of turns of the coil conductor portion has a section that is lower than the height of the turn on the inner-peripheral side thereof. The height of the plurality of turns in the coil conductor portion may gradually increase from the turn on the outer-peripheral side toward the turn on the inner-peripheral side. The coil conductor portion may have at least three turns, and the height of the turn at a central section excluding the innermost periphery and the outermost periphery, among the plurality of turns, may be the greatest.

Description

Coil parts

[0001] The present invention relates to a coil component in which a spiral-shaped coil conductor is embedded in a main body.

[0002] As a coil component having a spiral-shaped coil conductor embedded in a main body containing a magnetic material, Patent Document 1 discloses an inductor in which the flow of magnetic flux is optimized to reduce magnetic resistance. In this inductor, the maximum thickness of each of the multiple coil patterns gradually increases toward the outer side of the main body, and the line width of the bottom surface of the coil pattern is larger than the line width of the top surface.

[0003] Patent Document 2 discloses a chip electronic component that improves Q characteristics. This chip electronic component includes a magnetic body including an insulating substrate and a coil conductor pattern formed on at least one surface of the insulating substrate, and external electrodes formed on both ends of the magnetic body so as to be connected to the ends of the coil conductor pattern, and is configured such that, in a cross section in the longitudinal direction of the magnetic body, the thickness of the innermost coil conductor pattern among the coil conductor patterns is thinner than the thicknesses of the remaining coil conductor patterns.

[0004] Patent Document 3 discloses a thin-film inductor that improves both the Rdc and Ls characteristics. This thin-film inductor has a configuration in which the height of a plurality of coil patterns increases toward the outer surface of the body.

[0005] JP 2019-145768 A JP 2015-220452 A JP 2019-068048 A

[0006] When attempting to reduce the height of a coil component, the thickness of the main body that surrounds the coil conductor becomes thinner, resulting in a decrease in the strength of the main body. Because the main body is made of a material that contains a magnetic substance, it has lower toughness than the coil conductor. If the main body strength is insufficient, chipping is likely to occur on the surface of the main body when the main body material is cut with a dicing blade.

[0007] An object of the present invention is to provide a coil component that can improve the strength of the main body.

[0008] One aspect of the present invention is a coil component comprising: a main body portion containing a magnetic material; and a coil portion built into the main body portion and having a coil conductor portion including a spiral portion formed in a spiral shape by multiple turns around a winding axis along a first direction, wherein the outermost turn of the multiple turns of the coil conductor portion has a portion that is lower in height than the turns on the inner side.

[0009] According to this configuration, the strength of the molded body is improved by ensuring a sufficient distance between the outer edge of the molded body constituting the main body and the turns of the coil conductor. In particular, when the magnetic material contained in the main body is magnetic powder and the main body contains the magnetic powder and a binder that holds the magnetic powder, the strength of the molded body constituting the main body can be increased without increasing the binder content. Therefore, it is possible to increase the magnetic powder content (filling rate) in the main body, improving the magnetic properties of the main body and the characteristics of the coil component.

[0010] In the coil component, the coil conductor may include a first coil conductor having a first spiral portion having a spiral shape around a winding axis along a first direction, and a second coil conductor including a second spiral portion aligned with the first spiral portion along the first direction and having a spiral shape around the winding axis along the first direction, wherein the first coil conductor and the second coil conductor are electrically connected to each other through a via portion extending in the direction along the winding axis, thereby improving the strength of the molded body in the thickness direction of the entire main body.

[0011] In the coil component, the height of the multiple turns of the coil conductor along the winding axis may be gradually increased from the outermost turn toward the innermost turn, thereby making the filling of the molded body in the main body more uniform and improving the strength of the molded body.

[0012] In the coil component, the width of the multiple turns in the coil conductor in a direction perpendicular to the winding axis may be gradually increased from the outermost turn toward the innermost turn, thereby allowing the thickness of the plating to be adjusted depending on the width of the turns when the coil conductor is formed by plating.

[0013] In the coil component, the coil conductor may have at least three turns, and the height of the central turn of the multiple turns, excluding the innermost and outermost turns, may be set to be the highest. By reducing the height of the innermost turn of the spiral coil conductor, concentration of magnetic flux in that portion is avoided, and DC bias characteristics are improved.

[0014] According to the present invention, it is possible to provide a coil component that can improve the strength of the main body portion.

[0015] FIG. 1 is a plan view illustrating a coil component according to the present embodiment; FIG. 2 is a cross-sectional view illustrating a coil component according to the present embodiment; FIG. 3 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 4 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 5 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 6 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 7 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 8 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 9 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 10 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 11 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment; FIG. 12 is an explanatory view of an example of a manufacturing method for the coil component according to the present embodiment;

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same components will be denoted by the same reference numerals, and the description of components that have already been described will be omitted as appropriate.

[0017] (Overall configuration of coil component) Fig. 1 is a plan view illustrating a coil component according to this embodiment. Fig. 2 is a cross-sectional view illustrating a coil component according to this embodiment. Fig. 2 shows a cross-sectional view taken along line A-A' in Fig. 1. For ease of explanation, Fig. 1 shows a main body 10, external electrodes 21 and 22, and an exterior coating 50 (described later) with two-dot chain lines, and Fig. 2 shows the exterior coating 50 with a two-dot chain line.

[0018] The coil component 1 according to this embodiment includes a main body 10, a pair of external electrodes 21, 22 formed on the main body 10, and a coil portion 30 built into the main body 10. The main body 10 is formed in a substantially rectangular parallelepiped shape and has a mounting surface 11, a surface opposite the mounting surface 11 (first surface 12), and four side surfaces (first side surface 13a, second side surface 13b, third side surface 13c, and fourth side surface 13d). In this embodiment, the direction perpendicular to the first surface 12 is defined as the Z1-Z2 direction, one of the directions perpendicular to the Z1-Z2 direction is defined as the X1-X2 direction, and the direction perpendicular to the Z1-Z2 direction and the X1-X2 direction is defined as the Y1-Y2 direction. The first side surface 13a and the second side surface 13b of the main body 10 face opposite each other in the X1-X2 direction. The third side surface 13c and the fourth side surface 13d of the main body 10 face opposite to each other in the Y1-Y2 direction. The pair of external electrodes 21 and 22 are formed on the pair of side surfaces (the first side surface 13a and the second side surface 13b) of the main body 10.

[0019] (Main body portion) The main body portion 10 includes a binder and magnetic powder (magnetic material) held in the binder. As described above, the main body portion 10 is configured in the shape of a substantially rectangular parallelepiped, with a mounting surface 11, a first surface 12, and four side surfaces (first side surface 13a to fourth side surface 13d). The mounting surface 11, the first surface 12, and the four side surfaces (first side surface 13a to fourth side surface 13d) that form the main body portion 10 are referred to as the surface of the main body portion 10. The main body portion 10 has a built-in coil portion 30.

[0020] The material system of the magnetic powder is not limited. Specific examples of crystalline materials include Fe—Si—Cr alloys, Fe—Ni alloys, Fe—Co alloys, Fe—V alloys, Fe—Al alloys, Fe—Si alloys, Fe—Si—Al alloys, pure iron, and ferrite. Carbonyl iron powder is preferred as pure iron powder. Specific examples of amorphous materials include Fe—Si—B alloys, Fe—P—C alloys, and Co—Fe—Si—B alloys. Specific examples of composite materials include Fe—Zr alloys, Fe—Zr—B alloys, Fe—Si—B—Nb—Cu alloys, and Fe—Si—B—P—Cu alloys. When the magnetic powder is a metal powder containing Fe, the synergistic effect of improving magnetic properties is particularly large.

[0021] The binder contained in the main body 10 binds together particles of magnetic powder and the like contained in the main body 10. This binder is preferably an insulating material in order to impart insulation resistance to the main body 10.

[0022] The material constituting the binder may be an organic material, an inorganic material, or a mixture of an organic material and an inorganic material. The organic material may be a resin material. Examples of the resin material include acrylic resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, and polyester resin. Examples of the inorganic material include glass-based materials such as water glass.

[0023] When the main body portion 10 includes a binder and magnetic powder, the content of the magnetic powder in the main body portion 10 (filling rate, unit: volume %) is not limited. From the viewpoint of enhancing the magnetic properties of the main body portion 10, the higher the filling rate, the more preferable. However, increasing this filling rate relatively reduces the binder content in the main body portion 10, resulting in a decrease in the strength of the main body portion 10. As described below, the coil component 1 according to this embodiment increases the strength of the main body portion 10, particularly the strength of the portion of the main body portion 10 located around the outer periphery of the coil portion 30, making it easy to increase the filling rate of the magnetic powder. As a non-limiting example, the filling rate of the magnetic powder in the main body portion 10 of the coil component 1 according to this embodiment may preferably be 70 volume % or more, and more preferably 80 volume % or more.

[0024] (Coil Portion) The coil portion 30 has a coil conductor portion 31 including a spiral portion 311 formed in a spiral shape by multiple turns (e.g., a first turn T1, a second turn T2, and a third turn T3) around a winding axis O along a first direction (Z1-Z2 direction). The spiral shape, number of turns (number of turns), size, number of stages, etc. of the spiral portion 311 of the coil conductor portion 31 are appropriately selected depending on the specifications of the coil component 1. Furthermore, the conductor (conductive material) constituting the coil conductor portion 31 is not limited as long as it has appropriate conductivity. Specific examples of the conductor constituting the coil conductor portion 31 include metals such as copper, copper alloys, aluminum, and aluminum alloys, and the coil conductor portion 31 can be manufactured using a film formation technique such as plating.

[0025] In the coil component 1 according to this embodiment, the coil conductor portion 31 has a first coil conductor portion 31A formed on one surface side (the Z1 side in the Z1-Z2 direction) of the insulating substrate 90, and a second coil conductor portion 31B formed on the other surface side (the Z2 side in the Z1-Z2 direction) of the insulating substrate 90. Specifically, the coil conductor portion 31 has the first coil conductor portion 31A having a first spiral portion 311A ​​having a spiral shape around the winding axis O, and the second coil conductor portion 31B including a second spiral portion 311B that is aligned with the first spiral portion 311A ​​along the Z1-Z2 direction and has a spiral shape around the winding axis O.

[0026] In the first spiral portion 311A, when viewed from the Z1 side in the Z1-Z2 direction, the conductor is arranged in a spiral shape that moves clockwise away from the winding axis O from one end, which is the inner end, to the other end, which is the outer end.

[0027] When viewed from the Z1 side in the Z1-Z2 direction, second spiral portion 311B has a spiral shape that moves away from winding axis O from one end, which is the inner circumferential end, to the other end, which is the outer circumferential end. In second spiral portion 311B, the conductor is arranged in a spiral shape that moves away from winding axis O in the opposite direction to first spiral portion 311A ​​(counterclockwise in FIG. 1).

[0028] The first coil conductor portion 31A and the second coil conductor portion 31B are electrically connected to each other via a via portion VP that is provided in a through hole of the insulating substrate 90 and extends in a direction along the winding axis O. That is, the coil conductor portion 31 has the first coil conductor portion 31A, the second coil conductor portion 31B, and the via portion VP.

[0029] The coil conductor portion 31 includes a lead portion 312 at each end. In this embodiment, a first lead portion 312A is provided at the end of the first spiral portion 311A, and a second lead portion 312B is provided at the end of the second spiral portion 311B. The first lead portion 312A is exposed from the first side surface 13a of the main body portion 10, and the second lead portion 312B is exposed from the second side surface 13b of the main body portion 10. The exposed portion of the first lead portion 312A is in conductive contact with the external electrode 21, and the exposed portion of the second lead portion 312B is in conductive contact with the external electrode 22.

[0030] (External Electrodes) The external electrodes 21, 22 are formed on a pair of side surfaces of the main body 10, the first side surface 13a and the second side surface 13b. The external electrode 21 is formed so as to cover at least the first side surface 13a, and the external electrode 22 is formed so as to cover at least the second side surface 13b. Each of the external electrodes 21, 22 may overlap a portion of the mounting surface 11 or a portion of the first surface 12. The external electrodes 21, 22 are electrically isolated from each other. The material and configuration of the external electrodes 21, 22 are not limited as long as they have appropriate conductivity. One non-limiting example of the external electrodes 21, 22 is a layer having a Cu-plated / Ni-plated / Sn-plated structure from the side closest to the surface of the main body 10.

[0031] (External Coating) An external coating 50 is provided as an insulating layer on the surface of the main body 10 on which conductive members such as the external electrodes 21 and 22 are not formed. The external coating 50 may include a layer made of resin with an average thickness of 0.10 μm to 15.0 μm. This makes it easy to maintain the magnetic properties of the coil component 1, improve the insulation of the surface of the coil component 1 to increase the reliability of the coil component 1, and improve the appearance of the coil component 1. The coil component 1 does not necessarily have to include the external coating 50. The external coating 50 can be formed at any position on the surface of the main body 10 depending on the purpose.

[0032] (Height of Coil Conductor Portion) In the coil component 1 having the above-described configuration, the outermost turn of the multiple turns of the coil conductor portion 31 has a portion that is lower in height than the innermost turns. Here, in this embodiment, the spiral portion 311 of the coil conductor portion 31 is provided in a spiral shape with three turns (first turn T1, second turn T2, and third turn T3) when viewed in the Z1-Z2 direction. The innermost turn is the first turn T1, the second innermost turn is the second turn T2, and the outermost turn is the third turn T3.

[0033] When the coil conductor portion 31 includes a first coil conductor portion 31A arranged on one side (Z1 side in the Z1-Z2 direction) of the insulating substrate 90 and a second coil conductor portion 31B arranged on the other side (Z2 side in the Z1-Z2 direction), the first turn T1, second turn T2 and third turn T3 of the first coil conductor portion 31A and the first turn T1, second turn T2 and third turn T3 of the second coil conductor portion 31B are arranged in positions that overlap each other when viewed in the Z1-Z2 direction.

[0034] In the coil component 1, the heights of the multiple turns in the coil conductor portion 31 (the length in the Z1-Z2 direction based on the surface of the insulating substrate 90 on which the coil conductor portion 31 is formed) are set so as to gradually increase from the outermost turn toward the innermost turn. In the example shown in Fig. 2, the heights increase in the order of the third turn T3, the second turn T2, and the first turn T1. In other words, the height of the first turn T1 on the innermost side is the highest, and the height of the third turn T3 on the outermost side is the lowest.

[0035] This ensures a sufficient distance in the Z1-Z2 direction from the outer edge (mounting surface 11 and first surface 12) of the molded body constituting the main body 10 to the third turn T3 of the coil conductor 31, improving the strength of the molded body of the main body 10. Furthermore, by gradually increasing the distance from the outer circumferential turn to the inner circumferential turn of the coil conductor 31, the filling rate of the magnetic powder contained in the main body 10 constituted by the molded body becomes more uniform, and the strength of the molded body of the main body 10 is further improved.

[0036] (Method for Manufacturing Coil Component) Next, an example of a method for manufacturing the coil component 1 according to this embodiment will be described. Note that in the following manufacturing method, an example will be described in which a plurality of coil components 1 are manufactured at once.

[0037] 3A to 10 are explanatory views of an example of a manufacturing method for a coil component according to this embodiment. First, as shown in the XY plan view of FIG. 3A and the XZ cross-sectional view of FIG. 3B (the cross-section taken along line B-B' in FIG. 3A), multiple coil conductors 31 (first coil conductor 31A, second coil conductor 31B) are formed. Specifically, the first coil conductor 31A is formed on one surface of an insulating sheet substrate 91 (specifically, the surface on the Z1 side in the Z1-Z2 direction), and the second coil conductor 31B is formed on the other surface of the sheet substrate 91 (specifically, the surface on the Z2 side in the Z1-Z2 direction). The first coil conductor 31A and the second coil conductor 31B can be formed by a plating process. In this embodiment, via portions VP and first and second lead portions 312A and 312B are also formed simultaneously in this process.

[0038] Here, the sheet substrate 91 is not particularly limited as long as it has the mechanical properties necessary to function as a support when forming the coil conductor portion 31 and the like, and the suitability (removal properties) for the process described below. Examples of materials constituting the sheet substrate 91 include organic materials, inorganic materials, and composite materials thereof. Specific examples of organic materials include thermoplastic resins such as polyimide resin and polyethylene resin, thermosetting resins such as epoxy resin and phenolic resin, and cellulose. Specific examples of inorganic materials include oxide-based materials such as glass and alumina, metal-based materials such as aluminum and magnesium, and inorganic salt-based materials such as calcium carbonate. Specific examples of composite materials include a structure in which an inorganic material is dispersed in an organic material matrix. Among these materials, polyimide resin and epoxy resin are preferred. In particular, polyimide resin is most preferred in combination with a plating process. A seed layer made of a conductive material is provided on the surface of the sheet substrate 91.

[0039] The coil conductor portion 31 (the first coil conductor portion 31A and the second coil conductor portion 31B) includes a portion made of a plating layer formed by a plating process, and the lead portion 312 (the first lead portion 312A and the second lead portion 312B) is also formed by this plating process.

[0040] In one example of the plating process, a photosensitive resist is first applied to the surface of the sheet substrate 91, which is made of a seed layer, and an opening pattern is formed from the hardened photosensitive resist by photolithography and etching. The seed layer is exposed at the bottom of the opening pattern. Next, a plating layer of Cu (copper) or the like is grown on the seed layer exposed at the bottom of the opening pattern by electrolytic plating, in which an electric current is passed through the seed layer.

[0041] After forming a first plating layer of a predetermined thickness having a shape corresponding to the opening pattern, the photosensitive resist is removed and the seed layer is etched away, removing the portions of the seed layer where the first plating layer is not formed.

[0042] Next, a current is passed through the first plating layer to grow a second plating layer on the first plating layer, thereby forming the coil conductor portion 31 with a predetermined thickness. However, the plating process is not limited to this.

[0043] In such a plating process, the thickness of the plating layer varies depending on plating conditions such as the width of the turn, the distance to adjacent patterns (adjacent turns or power supply lines), the width of adjacent patterns, the distance between patterns, and the supply and agitation of the plating solution.

[0044] In this embodiment, the thickness of the coil conductor 31 grown by plating is controlled by setting these various plating conditions. When multiple plating processes are performed to grow the plating layer, the plating thickness for each turn may be adjusted by adjusting the growth thickness of any of the plating layers or by adjusting the growth thickness of all of the plating layers. This allows the outermost turn of the multiple turns of the coil conductor 31 to have a portion that is lower in height than the turns on the inner periphery. For example, the plating growth is controlled so that the height of the multiple turns of the coil conductor 31 gradually increases from the outermost turn toward the innermost turn.

[0045] After the coil conductor portion 31 and the like are formed by the plating process, at least a portion of the sheet base material 91 is removed. Specifically, the sheet base material 91 is removed so as to include a region of the sheet base material 91 that is surrounded by the inner edge of the coil conductor portion 31 when viewed in the first direction (Z1-Z2 direction).

[0046] The specific removal process for the sheet substrate 91 is set appropriately depending on the constituent material of the sheet substrate 91. Removal processes are broadly classified into dry processes such as plasma etching and wet processes such as wet etching. A portion of the sheet substrate 91 may be removed by the removal process, with the remaining portion remaining unremoved. For example, the sheet substrate 91 may be made of a composite material of an organic material and an inorganic material, and only the organic material may be removed by the removal process.

[0047] After removing a portion of the sheet substrate 91 , an insulating portion (not shown) is formed so as to contact the exposed surface of the coil conductor portion 31 .

[0048] Next, a material containing magnetic powder is supplied to cover at least both sides in the first direction (Z1-Z2 direction) of the coil conductor portion 31 and the lead-out portion 312, and is molded into a plate material. An example of this molding process is a molding process in which the coil portion 30 is surrounded by a material containing magnetic material. Specific examples of molding processes include placing the product formed in the previous process in a mold and forming it by compression molding a material containing magnetic material, or transfer molding a material containing magnetic powder or a component that is the raw material for that material.

[0049] The compression molding process is shown in the schematic cross-sectional views of Figures 4 and 5. First, as shown in Figure 4, a material containing a magnetic material is placed in the cavity C of the lower mold ML. At that time, the product A1 formed in the previous process shown in Figure 3 is set in the cavity C so that it is embedded in the material containing the magnetic material. Next, the upper mold MU is brought close to the lower mold ML, and the material containing the magnetic material with the product A1 embedded in it is compressed between the lower mold ML and the upper mold MU within the cavity C of the lower mold ML.

[0050] After filling the cavity C with the material containing the magnetic material and compressing it, the filling material is solidified or hardened and then demolded (see FIG. 5). FIG. 6 shows an XY plan view of product B1 made of the plate material obtained after demolding. In product B1, the entire periphery of product A1 is covered with main body material 100 (solidified or hardened material containing the magnetic material).

[0051] Next, the product B1 made of a plate material is cut so that the first direction (Z1-Z2 direction) is parallel to the cutting surface. Specifically, the product B1 is divided at predetermined positions as shown in the XY plan view of FIG. 7 and the XZ cross-sectional view of FIG. 8 (cross-section taken along line CC' in FIG. 7). In this step, predetermined regions (hatched regions DL in FIG. 7) around the coil conductor portions 31 in the product B1 are diced. Dicing forms a plurality of products C1 (see FIG. 8) each having a coil portion 30 and a main body portion 10 formed by dividing the main body material 100 covering the coil portion 30.

[0052] Next, as shown in the XZ cross-sectional view of Fig. 9, an exterior coating 50 is applied to a portion of the surface of the product C1. The surface to which the exterior coating 50 is applied is a surface of the outer surface of the product C1 on which an electrode will not be formed in a later step.

[0053] Next, as shown in the XZ cross-sectional view of Figure 10, external electrodes 21, 22 are formed on the surface of the product C1 that is not coated with the exterior coating 50. The method for forming the external electrodes 21, 22 is not limited, and examples include a plating process and a printing process using a conductive paste. In this way, the coil component 1 according to this embodiment is manufactured.

[0054] 7, when the product B1 is divided by dicing, chipping may occur on the surface of the cut main body 10. The magnetic material used as the material for the main body 10 has low toughness after solidification (hardening), and chipping may occur on the surface due to contact with the dicing blade during dicing.

[0055] Chipping is likely to occur on the side surfaces (first side surface 13a, second side surface 13b, third side surface 13c, and fourth side surface 13d shown in FIG. 1 ) and corners of the main body portion 10. Generally, increasing the amount of binder (amount of resin) contained in the material of the main body portion 10 can increase the toughness of the main body portion 10, but this reduces the amount of magnetic material, resulting in a deterioration of magnetic properties. Furthermore, by increasing the thickness of the main body portion 10, the main body portion 10 can be made sufficiently strong, thereby suppressing the occurrence of chipping due to excessive mechanical stress during dicing. However, increasing the thickness of the main body portion 10 makes it difficult to reduce the height of the coil component 1.

[0056] The relationship between the distance A shown in Fig. 10 and the occurrence of chipping will be described below. Here, the distance A is the length from the top surface (the surface on the Z1 side in the Z1-Z2 direction) of the third turn T3, which is the outermost periphery of the coil conductor portion 31, to the first surface 12 of the main body portion 10. In other words, the longer the distance A, the greater the amount of the main body portion 10 that covers the upper part of the third turn T3, which is the outermost periphery.

[0057] In both the comparative example and the example, the width of the lead-out portion 312 shown in FIG. 7 is 50 μm, and the width of the dicing blade is 300 μm. The spacing A in the comparative example is 40.6 μm, 45.7 μm, 66.9 μm, 63.8 μm, and 38.9 μm. The spacing A in the example is 81.8 μm, 73.6 μm, 101.3 μm, 103.7 μm, and 98.4 μm. The occurrence and size of chipping in each sample were investigated, and the results are shown in Table 1. The chipping size is the length of the chipping in the Y1-Y2 direction.

[0058]

[0059] As shown in Table 1, chipping exceeding 100 μm occurred in all samples in the comparative example, while chipping exceeding 70 μm did not occur in any samples in the examples.

[0060] FIG. 11 shows the relationship between the spacing A and chipping size. The horizontal axis of FIG. 11 represents the spacing A shown in Table 1, and the vertical axis represents the chipping size shown in Table 1. As shown in FIG. 11, the relationship between the spacing A and the chipping size clearly distinguishes between group G1 of the example and group G2 of the comparative example. This indicates that setting the spacing A to 70 μm or greater significantly reduces the chipping size. If the chipping size is large, the lead-out portion 312 may be exposed from the surface of the main body portion 10, or the unevenness caused by the chipping may deteriorate the adhesion of the external electrodes 21 and 22 formed thereon. In the example, the size is small enough to prevent such chipping problems. Based on the above results, by reducing the height of the third turn T3, which is the outermost periphery, and increasing the amount of the main body portion 10 covering the third turn T3, it is possible to increase the strength of the main body portion 10 and suppress chipping without increasing the maximum height of the coil conductor portion 31. Therefore, chipping is suppressed without increasing the height of the main body portion 10 of the coil component 1.

[0061] (Another embodiment: part 1) Fig. 12 is a cross-sectional view illustrating a coil component according to another embodiment (part 1). In the coil component 1B shown in Fig. 12, the coil conductor portion 31 has at least three turns. In the example shown in Fig. 12, the coil conductor portion 31 has three turns (a first turn T1 at the innermost periphery, a second turn T2 second from the innermost side, and a third turn T3 at the outermost periphery). In this coil conductor portion 31, the height of the turn (second turn T2) in the central portion of the multiple turns, excluding the innermost periphery (first turn T1) and the outermost periphery (third turn T3), is set to be the highest.

[0062] 13 is a diagram showing an example of a resist opening pattern on a seed layer used in a plating process. When forming the coil conductor portion 31 of the coil component 1B shown in FIG. 12, for example, as shown in FIG. 13, the opening pattern P used in the plating process may be a dummy opening pattern P-D provided inside the opening pattern P-T1 that forms the innermost first turn T1. By providing the dummy opening pattern P-D, a plating layer is grown more in the dummy opening pattern P-D during the plating process, thereby relatively suppressing the growth of the plating layer on the innermost first turn T1.

[0063] Furthermore, since the opening pattern P-T3 forming the outermost third turn T3 is close to the opening pattern P-E forming the lead-out portion 312 and surrounding patterns (such as the power supply pattern), the growth of the plating layer on the outermost opening pattern P-T3 is suppressed.

[0064] On the other hand, the opening pattern PT2 forming the second turn T2 in the center is less susceptible to such influence, and the plating layer grows relatively more than the first turn T1 and the third turn T3.

[0065] In this way, in coil component 1B, the height of the third turn T3, which is the outermost turn, is low, so that the interval A shown in Fig. 10 can be set sufficiently long, thereby suppressing chipping. Furthermore, by reducing the height of the first turn T1, which is the innermost turn, it is possible to avoid concentration of magnetic flux at the first turn T1, and to obtain good DC superposition characteristics.

[0066] (Another embodiment: part 2) Fig. 14 is a cross-sectional view illustrating a coil component according to another embodiment (part 2). In a coil component 1C shown in Fig. 14, the width of the turns of the coil conductor portion 31 gradually increases from the outer periphery toward the inner periphery. In the example shown in Fig. 14, the coil conductor portion 31 has three turns (the first turn T1 at the innermost periphery, the second turn T2 from the innermost periphery, and the third turn T3 at the outermost periphery). In this coil conductor portion 31, the width of the third turn T3 at the outermost periphery is the narrowest, and the width gradually increases from the second turn T2 toward the first turn T1.

[0067] 15 is a diagram showing an example of a resist opening pattern on a seed layer used in a plating process. The width of the opening pattern P shown in FIG. 15 gradually increases from the outer periphery toward the inner periphery, similar to the width of the turns of the coil conductor portion 31 of the coil component 1C shown in FIG. 14. In the plating process, the wider the opening pattern P, the more the plating layer grows, and the thicker the turns of the coil conductor portion 31 become. Therefore, the thickness of the plating can be adjusted by changing the width of the turns of the opening pattern P.

[0068] Thus, according to this embodiment, by making the outermost turn of the multiple turns of the coil conductor portion 31 have a portion that is lower in height than the turns on the inner periphery, the strength of the main body portion 10 can be improved to the extent that chipping during dicing can be suppressed.

[0069] The above-described embodiments and examples have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0070] For example, in the above description, an example was shown in which the coil conductor portion 31 includes the first coil conductor portion 31A and the second coil conductor portion 31B, but a configuration including only either the first coil conductor portion 31A or the second coil conductor portion 31B is also possible. Furthermore, the coil portion 30 may be configured without including the insulating substrate 90. For example, the sheet base material 91 that becomes the insulating substrate 90 may be removed during the manufacturing process so that the insulating substrate 90 does not remain in the manufactured coil components 1, 1B, and 1C. Furthermore, while the coil conductor portion 31 is made of one type of conductive material, the present invention is not limited to this and may be made of multiple materials.

[0071] DESCRIPTION OF SYMBOLS 1, 1B, 1C... Coil component 10... Main body portion 11... Mounting surface 12... First surface 13a... First side surface 13b... Second side surface 13c... Third side surface 13d... Fourth side surface 21, 22... External electrodes 30... Coil portion 31... Coil conductor portion 31A... First coil conductor portion 31B... Second coil conductor portion 311... Spiral portion 311A... First spiral portion 311B... Second spiral portion 312... Lead portion 312A... First lead portion 312B... Second lead portion 50... Exterior coating 90... Insulating substrate 91... Sheet base material 100... Main body material A1... Product B1... Product C... Cavity C1... Product DL... Region G1, G2... Group MU... Upper mold ML...Lower die O...Reel shaft P...Opening pattern PD...Dummy opening pattern PE, P-T1, P-T2, P-T3...Opening patterns T1...First turn T2...Second turn T3...Third turn VP...Via portion A...Spacing

Claims

1. A coil component comprising: a main body portion containing a magnetic material; and a coil portion having a coil conductor portion incorporated in the main body portion and including a spiral portion provided in a spiral shape by a plurality of turns around a winding axis along a first direction, wherein an outermost turn among the plurality of turns of the coil conductor portion has a portion lower than a height of an inner peripheral turn.

2. The coil component according to claim 1, wherein the coil conductor portion includes: a first coil conductor portion having a first spiral portion having a spiral shape around a winding axis along the first direction; and a second coil conductor portion including a second spiral portion arranged along the first spiral portion and having a spiral shape around a winding axis along the first direction, and the first coil conductor portion and the second coil conductor portion are electrically connected to each other via a via portion extending in a direction along the winding axis.

3. The coil component according to claim 1, wherein a height of the plurality of turns of the coil conductor portion in a direction along the winding axis gradually increases from an outer peripheral turn toward an inner peripheral turn.

4. The coil component according to claim 1, wherein a width of the plurality of turns of the coil conductor portion in a direction perpendicular to the winding axis gradually widens from an outer peripheral turn toward an inner peripheral turn.

5. The coil component according to claim 1, wherein the coil conductor portion has at least three turns, and a height of turns in a central portion excluding the innermost and outermost turns among the plurality of turns is provided to be the highest.