Coil components

Abstract

To provide a coil component that allows for easy detection of defective products. [Solution] In the coil component 1, if a defect such as misalignment occurs during the individualization process, a portion of the coil conductor 5 may be exposed from any of the end faces 2a, 2b and side faces 2e, 2f of the base body 2. In the pillar portion 8, the side faces 8g to 8j are made of discolored portions 12 having a different color from the main body portion 11, thereby increasing the color difference between the main body portion 11 and the discolored portions 12. Therefore, even if the base body 2 is translucent, the exposure of the pillar portion 8 from the cut surface can be easily detected, and as a result, defective products caused by misalignment can be easily detected.

Description

Technical Field

[0001] The present invention relates to a coil component.

Background Art

[0002] Patent Document 1 discloses a coil component including a body having a laminated structure composed of a plurality of insulating layers and a coil conductor provided in the body. In this document, the coil conductor has a coil axis parallel to the stacking direction of the body.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A body having a laminated structure like the coil component according to the above-described prior art is cut and fragmented in the manufacturing process so that a plane parallel to the stacking direction appears. However, if the coil conductor is exposed from the cut surface of the body during cutting, it becomes a defective product.

[0005] The inventors have found that even if the coil conductor is exposed from the cut surface of the body, it is difficult to detect defective products because the exposed area is small for a coil conductor having a coil axis parallel to the stacking direction of the body. For a coil conductor having a coil axis orthogonal to the stacking direction of the body, the exposed area increases, and as a result, it is possible to easily detect defective products.

[0006] The inventors have further studied the detection of defective products of a coil conductor having a coil axis orthogonal to the stacking direction of the body and have newly found a technique that can further easily detect defective products.

[0007] One aspect of the present invention aims to provide a coil component that allows for easy detection of defective products. [Means for solving the problem]

[0008] A coil component according to one aspect of the present invention comprises a base body composed of a plurality of stacked insulating layers, and a coil conductor provided within the base body and having a coil axis perpendicular to the stacking direction of the base body, wherein the coil conductor has an orientation surface facing the surface side of the base body parallel to the stacking direction, and has a main body portion and a discolored portion having a different color from the main body portion and constituting at least the orientation surface.

[0009] In the above-described coil component, assuming that the surface of the base body parallel to the stacking direction is a cut surface created by fragmentation, the orientation surface of the coil conductor facing that surface is composed of a discolored portion having a different color from the main body, resulting in a large color difference between the main body and the discolored portion of the coil conductor. Therefore, regardless of whether the base body is colorless or colored, if the coil conductor is exposed from the cut surface of the base body, the exposure can be easily detected, making it easy to detect defective products. [Effects of the Invention]

[0010] According to various aspects of the present invention, a coil component is provided that allows for easy detection of defective products. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of a coil component according to one embodiment. [Figure 2] Figure 1 is a perspective view showing the coil conductor. [Figure 3] Figure 1 is an exploded perspective view showing the configuration of each layer of the coil component. [Figure 4] This figure shows the configuration of the wiring section of the first layer shown in Figure 3. [Figure 5] Figure 4 is a cross-sectional view of the VV line in the second wiring section. [Figure 6]This figure shows the configuration of the wiring section of the second layer shown in Figure 3. [Figure 7] This figure shows the configuration of the wiring section of the third layer shown in Figure 3. [Figure 8] This figure shows the configuration of the wiring section of the fourth layer shown in Figure 3. [Figure 9] This figure shows the configuration of the wiring section of the fifth layer shown in Figure 3. [Figure 10] Figure 1 is a flowchart showing the procedure for manufacturing the coil component. [Figure 11] Figure 1 is a side view of the coil component. [Figure 12] Figure 11 shows a cross-section of the coil component along line XII-XII. [Figure 13] This is a diagram showing the structure of the pillar section. [Figure 14] This diagram shows the appearance of the end face of the base material where cutting misalignment occurred. [Modes for carrying out the invention]

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0013] Referring to FIG. 1, the coil component according to the present embodiment will be described. As shown in FIGS. 1 and 2, a coil component 1 according to an embodiment includes a base body 2, a pair of bottom electrodes 3 and 4, and a coil conductor 5. The coil conductor 5 is provided in the base body 2 and, as will be described later, includes a plurality of second wiring portions 6, a plurality of pairs of pillar portions 8, and a plurality of first wiring portions 7. Specifically, the coil conductor 5 includes five second wiring portions 6, five pairs of pillar portions 8, and four first wiring portions 7. The coil conductor 5 has a coil axis along the second direction D2 to be described later and circulates around the coil axis. The coil conductor 5 according to the present embodiment circulates around the coil axis approximately 4.5 turns. The number of turns of the coil conductor 5 can be appropriately increased or decreased. Accordingly, the number of pairs of pillar portions 8, the number of first wiring portions 7, and the number of second wiring portions 6 can also be increased or decreased.

[0014] The base body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape in which the corners and ridge lines are chamfered, and a rectangular parallelepiped shape in which the corners and ridge lines are rounded. The base body 2 has, as outer surfaces, a pair of end faces 2a and 2b, a pair of main faces 2c and 2d, and a pair of side faces 2e and 2f. The end faces 2a and 2b face each other. The main faces 2c and 2d face each other. The side faces 2e and 2f face each other. Hereinafter, the opposing direction of the end faces 2a and 2b is defined as the first direction D1, the opposing direction of the side faces 2e and 2f is defined as the second direction D2, and the opposing direction of the main faces 2c and 2d is defined as the third direction D3. The first direction D1, the third direction D3, and the second direction D2 are substantially orthogonal to each other.

[0015] The end faces 2a and 2b extend in the third direction D3 so as to connect the main faces 2c and 2d. The end faces 2a and 2b also extend in the second direction D2 so as to connect the side faces 2e and 2f. The main faces 2c and 2d extend in the first direction D1 so as to connect the end faces 2a and 2b. The main faces 2c and 2d also extend in the second direction D2 so as to connect the side faces 2e and 2f. The side faces 2e and 2f extend in the first direction D1 so as to connect the end faces 2a and 2b. The side faces 2e and 2f also extend in the third direction D3 so as to connect the main faces 2c and 2d.

[0016] The main surface 2d is the mounting surface of the base body 2. For example, when mounting the coil component 1 on other electronic devices (such as a circuit substrate or a multilayer electronic component) not shown in the figure, it is the surface facing the other electronic devices. The end surfaces 2a and 2b are surfaces continuous from the mounting surface (i.e., the main surface 2d).

[0017] The length of the base body 2 in the first direction D1 is longer than the length of the base body 2 in the third direction D3 and the length of the base body 2 in the second direction D2. The length of the base body 2 in the third direction D3 is shorter than the length of the base body 2 in the second direction D2. That is, in the present embodiment, the end surfaces 2a, 2b, the main surfaces 2c, 2d, and the side surfaces 2e, 2f exhibit a rectangular shape. The length of the base body 2 in the third direction D3 may be equal to the length of the base body 2 in the second direction D2, or may be longer than the length of the base body 2 in the second direction D2.

[0018] In addition, in the present embodiment, "equivalent" may include values with slight differences or manufacturing errors within a preset range in addition to being equal. For example, if a plurality of values are included within the range of ±5% of the average value of the plurality of values, the plurality of values are defined as equivalent.

[0019] As shown in FIG. 3, the base body 2 has a structure in which a plurality of base body layers (insulating layers) are laminated in the third direction D3. In the present embodiment, the base body 2 is composed of nine base body layers 21 to 29. That is, the lamination direction of the base body 2 coincides with the third direction D3. Wiring portions 6, 7, 8a to 8f constituting the coil conductor 5 are embedded in the base body layers 22 to 28. The base body 2 can be manufactured by sequentially laminating the base body layers 22 to 29 on the base body layer 21 as described in the manufacturing method described later. In the actual base body 2, the plurality of base body layers 21 to 29 may be integrated to such an extent that the boundaries between the layers are not visible, or may be integrated so that the boundaries between the layers are visible.

[0020] Each of the elemental layers 21-29 is mainly composed of an insulating material, and in this embodiment, it is composed of a translucent resin material. Therefore, the elemental 2 composed of the elemental layers 21-29 is translucent. The resin material includes, for example, at least one selected from liquid crystal polymer, polyimide resin, crystalline polystyrene, epoxy resin, acrylic resin, bismaleide resin, and fluororesin. The resin material may or may not contain a filler. The filler is, for example, an inorganic filler. An example of an inorganic filler is silica. Each of the wiring sections 6, 7, 8a-8f is mainly composed of a conductive material, and in this embodiment, as will be described later, it is mainly composed of Cu.

[0021] The base layer 21 is composed solely of the insulating material described above. The base layer 21 is located at the bottom of the base 2 and constitutes the main surface 2c.

[0022] As shown in Figures 3 and 4, the base layer 22 has a plurality of second wiring sections 6 (lower wiring sections) embedded in it, and the base layer 22 according to this embodiment contains five second wiring sections 6. The plurality of second wiring sections 6 all extend parallel to the first direction D1 and have the same length with respect to the first direction D1. The plurality of second wiring sections 6 are arranged at equal intervals with respect to the second direction D2. The plurality of second wiring sections 6 are spaced apart from the end faces 2a, 2b and sides 2e, 2f of the base 2. One end 6a of each second wiring section 6 in the direction of extension is located near the end face 2a, and the other end 6b is located near the end face 2b. The plurality of second wiring sections 6 are located on the main surface 2c side of the base 2 because the base layer 22 is laminated directly on the base layer 21 which constitutes the main surface 2c. The base layer 22 will also be referred to as the first base layer in the following description.

[0023] Each second wiring section 6 has a substantially rectangular cross-section in a cross-section perpendicular to its extending direction (i.e., the first direction D1), as shown in Figure 5. Each second wiring section 6 is also composed of a main body 9 and a colored layer 10 in a cross-section perpendicular to its extending direction. The main body 9 has a substantially rectangular cross-section and is made of a metallic material. Specifically, the main body 9 is made of Cu, and more specifically, it is made of Cu plating. The colored layer 10 is interposed at the interface between the main body 9 and the base layer 21. The colored layer 10 has a thin, layered cross-section and is made of a metallic material. In this embodiment, the colored layer 10 is made of Cr and has a different color from the main body 9 which is made of Cu. The colored layer 10 can be made of a material that has a higher adhesion force to the base layer 21 than the constituent material of the main body 9. In this case, the presence of the colored layer 10 at the interface between the main body 9 and the base layer 21 enhances the adhesion of the second wiring portion 6 to the base layer 21 compared to the case where the colored layer 10 is not present. When the main body 9 is formed by electroplating, the colored layer 10 can be used as a seed layer. In that case, if necessary, a coating layer covering the surface of the colored layer 10 may be formed by Cu sputtering. Each of the multiple second wiring portions 6 has an opposing surface 6c facing the main surface 2c of the base body 2, and the colored layer 10 is provided on each opposing surface 6c.

[0024] As shown in Figures 3 and 6, the base layers 23 to 26 each have embedded wiring sections 8a to 8d (pillar conductors) that constitute the pillar section 8 extending along the third direction D3. The wiring sections 8a to 8d are located in the same positions in all base layers 23 to 26 and overlap each other in the third direction D3. In the following description, base layers 23 to 26 will also be referred to as the second base layer.

[0025] Each wiring section 8a to 8d is composed of multiple pairs that form a pair with respect to the first direction D1, and in this embodiment, there are five pairs. Specifically, each wiring section 8a to 8d is arranged in two rows along the second direction D2 and is spaced equally apart with respect to the second direction D2. In the following description, the row of wiring sections 8a to 8d arranged in two rows on the end face 2a side will be referred to as the first row 8A, and the row on the end face 2b side will be referred to as the second row 8B. The wiring sections 8a to 8d of the first row 8A are positioned to correspond to one end 6a of the second wiring section 6, and the wiring sections 8a to 8d of the second row 8B are positioned to correspond to the other end 6b of the second wiring section 6. In this embodiment, each wiring section 8a to 8d has a roughly rectangular shape (for example, roughly square shape) when viewed from the third direction D3.

[0026] As shown in Figures 3 and 7, the base layer 27 has a plurality of first wiring sections 7 embedded in it, and in this embodiment, the base layer 27 includes four first wiring sections 7. The base layer 27 will also be referred to as the third base layer in the following description. Each first wiring section 7 has a pair of ends 7a and 7b and an inclined section 7c interposed between the pair of ends 7a and 7b. The pair of ends 7a and 7b and the inclined section 7c are configured to be continuous, with the pair of ends 7a and 7b located on both sides of the inclined section 7c with respect to the first direction D1. The pair of ends 7a and 7b consist of a first end 7a located closer to the end face 2a of the base 2 and a second end 7b located closer to the end face 2b of the base 2. The pair of ends 7a and 7b are offset from each other with respect to the second direction D2 when viewed from the third direction D3. In this embodiment, when viewed from the third direction D3, the first end 7a is located closer to the side surface 2f than the second end 7b. The inclined portion 7c extends in a direction inclined by a predetermined angle with respect to the first direction D1, connecting a pair of ends 7a and 7b that are offset from each other with respect to the second direction D2. The inclination angle with respect to the first direction D1 is the same for all first wiring sections 7. That is, the inclined portions 7c of the first wiring sections 7 are parallel to each other. In this embodiment, the four first wiring sections 7 are composed of first wiring sections 7A, 7B, 7C, and 7D, which are arranged in order from the side closest to the side 2f.

[0027] The first end 7a of the first wiring section 7 overlaps with one of the first row 8A and one of the multiple second wiring sections 6 of the wiring sections 8a to 8d, when viewed from the third direction D3. The second end 7b of the first wiring section 7 overlaps with one of the second row 8B and one of the multiple second wiring sections 6 of the wiring sections 8a to 8d, when viewed from the third direction D3. In this embodiment, the second end 7b of the first wiring section 7A overlaps with the first wiring section 8a to 8d of the second row 8B counting from the side 2f, and also with the end 6b of the first second wiring section 6 counting from the side 2f, while the first end 7a overlaps with the second wiring section 8a to 8d of the first row 8A counting from the side 2f, and also with the end 6a of the second second wiring section 6 counting from the side 2f. The second end 7b of the first wiring section 7B overlaps with the second wiring section 8a to 8d of the second row 8B, counting from the side 2f, and also overlaps with the end 6b of the second second wiring section 6, counting from the side 2f. The first end 7a overlaps with the third wiring section 8a to 8d of the first row 8A, counting from the side 2f, and also overlaps with the end 6a of the third second wiring section 6, counting from the side 2f. The second end 7b of the first wiring section 7C overlaps with the third wiring section 8a to 8d of the second row 8B, counting from the side 2f, and also with the end 6b of the third second wiring section 6, counting from the side 2f. The first end 7a overlaps with the fourth wiring section 8a to 8d of the first row 8A, counting from the side 2f, and also with the end 6a of the fourth second wiring section 6, counting from the side 2f. The second end 7b of the first wiring section 7C overlaps with the fourth wiring section 8a to 8d of the second row 8B, counting from the side 2f, and also with the end 6b of the fourth second wiring section 6, counting from the side 2f, while the first end 7a overlaps with the fifth wiring section 8a to 8d of the first row 8A, counting from the side 2f, and also with the end 6a of the fifth second wiring section 6, counting from the side 2f.

[0028] Furthermore, a pair of wiring sections 8e (first lead-out wiring sections) are embedded in the base layer 27. One of the pair of wiring sections 8e is positioned to overlap with one of the wiring sections 8a to 8d of the first row 8A, and the other of the pair of wiring sections 8e is positioned to overlap with one of the wiring sections 8a to 8d of the second row 8B. In this embodiment, one of the pair of wiring sections 8e overlaps with the first wiring section 8a to 8d of the first row 8A, counting from the side 2f, and also overlaps with the end 6a of the first second wiring section 6, counting from the side 2f, thus forming the end 5a of the coil conductor 5. The other of the pair of wiring sections 8e overlaps with the fifth wiring section 8a to 8d of the second row 8B, counting from the side 2f, and also overlaps with the end 6b of the fifth second wiring section 6, counting from the side 2f, thus forming the end 5b of the coil conductor 5.

[0029] As shown in Figures 3 and 8, a pair of wiring sections 8f (second lead-out wiring sections) are embedded in the base layer 28. The pair of wiring sections 8f are located in positions that overlap with the pair of wiring sections 8e of the base layer 27. Of the pair of wiring sections 8f, the wiring sections 8f on the end face 2a side and the side 2f side constitute the end 5a of the coil conductor 5, and the wiring sections 8f on the end face 2b side and the side 2e side constitute the end 5b of the coil conductor 5. The base layer 28 will also be referred to as the fourth base layer in the following description.

[0030] As shown in Figures 3 and 9, the base layer 29 is provided with a pair of bottom electrodes 3 and 4 (terminal electrodes). From the viewpoint of the manufacturing procedure, the base layer 29 is located at the top of the base body 2 and constitutes the main surface 2d. In other words, the pair of bottom electrodes 3 and 4 are provided on the main surface 2d of the base body 2. The base layer 29 will also be referred to as the fifth base layer in the following description. Both the pair of bottom electrodes 3 and 4 are rectangular in shape when viewed from the third direction D3. The pair of bottom electrodes 3 and 4 may have the same shape and dimensions. In this embodiment, the pair of bottom electrodes 3 and 4 are aligned in the first direction D1, and the bottom electrode 3 located on the end face 2a side of the base body 2 overlaps with the wiring portion 8f on the end face 2a side and the side 2f side of the pair of wiring portions 8f of the base layer 28, while the bottom electrode 4 located on the end face 2b side of the base body 2 overlaps with the wiring portion 8f on the end face 2b side and the side 2e side of the pair of wiring portions 8f of the base layer 28. The pair of bottom electrodes 3 and 4 are embedded inside the base body 2 (more specifically inside the base body layer 29) and are exposed from the main surface 2d. The pair of bottom electrodes 3 and 4 may be partially or entirely provided on the main surface 2d of the base body 2.

[0031] Coil component 1 can be manufactured by the manufacturing method shown in the flowchart of Figure 10.

[0032] When fabricating coil component 1, multiple insulating sheets (green sheets) corresponding to each of the base layers 21 to 29 are prepared. Each green sheet has dimensions larger than the dimensions of the base 2 so that multiple coil components can be formed at once.

[0033] Then, as the first step S1, a green sheet that will become the first base layer 22 is laminated onto a green sheet that will become the base layer 21. Specifically, a plurality of second wiring sections 6 are formed on the base layer 21, and then the second wiring sections 6 are embedded with the resin material that constitutes the first base layer 22. More specifically, predetermined resist partitions are provided on the base layer 21, and the main body 9 is formed by electroplating using a colored layer 10 as a seed layer between the partitions, and then the resist partitions are removed to obtain the second wiring sections 6.

[0034] Next, in the second step S2, the green sheets that will become the second base layer 23 to 26 are sequentially stacked on the green sheet that will become the first base layer 22. If the second base layer 23 to 26 consists of multiple layers, as in this embodiment, the second step S2 is repeated multiple times. That is, if the number of layers in the second base layer is N, the second step S2 is repeated N times. If the second base layer is a single layer, the second step S2 is performed only once and does not need to be repeated.

[0035] Next, in the third step S3, a green sheet that will become the third elemental layer 27 is stacked on top of the green sheets that will become the second elemental layers 23-26 (specifically, on the uppermost second elemental layer 26). Furthermore, in the fourth step S4, a green sheet that will become the fourth elemental layer 28 is stacked on top of the green sheet that will become the third elemental layer 27. Then, in the fifth step S5, a green sheet that will become the fifth elemental layer 29 is stacked on top of the green sheet that will become the fourth elemental layer 28. The bottom electrodes 3 and 4 may be provided on the green sheet that will become the fifth elemental layer 29 before stacking it, or they may be provided on the green sheet that will become the fifth elemental layer 29 after stacking it.

[0036] Finally, in the fourth step S4, multiple green sheets corresponding to each of the base layers 21-29 are cut into individual pieces along the stacking direction (i.e., the third direction D3) to the dimensions of the base 2. At this time, the end faces 2a, 2b and side faces 2e, 2f of the base 2, which are parallel to the stacking direction, appear as the cut surfaces.

[0037] Next, the pillar portion 8 according to this embodiment will be described with reference to Figures 1, 2, and 11-13.

[0038] In this embodiment, the pillar portion 8 is formed by stacking the wiring portions 8a to 8d of each of the base layers 23 to 26. The pillar portion 8 is composed of multiple pairs that form a pair with respect to the first direction D1, and in this embodiment, it is composed of five pairs. The five pairs of pillar portions 8 are aligned in two rows, the first row 8A and the second row 8B, along the second direction D2, similar to the wiring portions 8a to 8d.

[0039] Each of the pillar sections 8 is connected to both ends 6a and 6b of the second wiring section 6, as shown in Figure 11. Specifically, end 6a of the second wiring section 6 is connected to one end of the pillar section 8 (the end on the main surface 2c side), and end 6b of the second wiring section 6 is also connected to one end of the pillar section 8. Each of the pillar sections 8 extends from both ends 6a and 6b of the second wiring section 6 toward the main surface 2d of the base body 2. In other words, one second wiring section 6 spans two pillar sections 8.

[0040] In this embodiment, the first pillar portion 8 of the first row 8A, counting from the side 2f, has one end connected to the end 6a of the first second wiring portion 6, counting from the side 2f, and the other end connected to the bottom electrode 3 provided on the main surface 2d via wiring portions 8e and 8f that constitute the end 5a of the coil conductor 5. The second to fifth pillar portions 8 of the first row 8A, counting from the side 2f, have one end connected to the ends 6a of the second to fifth second wiring portions 6, counting from the side 2f, and the other end connected to the first end 7a of the first to fourth first wiring portions 7, counting from the side 2f.

[0041] In this embodiment, the first to fourth pillar sections 8 of the second row 8B, counting from the side 2f, have one end connected to the end 6b of the first to fourth second wiring sections 6, counting from the side 2f, and the other end connected to the second end 7b of the first to fourth first wiring sections 7, counting from the side 2f. The fifth pillar section 8 of the second row 8B, counting from the side 2f, has one end connected to the end 6b of the fifth second wiring section 6, counting from the side 2f, and the other end connected to the bottom electrode 4 provided on the main surface 2d via wiring sections 8e and 8f that constitute the end 5b of the coil conductor 5.

[0042] Each pillar section 8, like each wiring section 8a to 8d, has a substantially rectangular cross-sectional shape with respect to a cross-section perpendicular to its extending direction (i.e., the third direction D3). In this embodiment, it has a substantially square cross-sectional shape. Specifically, each pillar section 8 has four sides 8g to 8j corresponding to the end faces 2a, 2b and sides 2e, 2f of the base body 2. In the pillar section 8 shown in Figures 12 and 13, side 8g is a surface parallel to the end face 2a of the base body 2 and faces the end face 2a side of the base body 2. Similarly, side 8h is a surface parallel to the end face 2b of the base body 2 and faces the end face 2b side of the base body 2. Side 8i is a surface parallel to the side 2f of the base body 2 and faces the side 2f side of the base body 2. Similarly, side 8j is a surface parallel to the side 2e of the base body 2 and faces the side 2e side of the base body 2.

[0043] Each pillar portion 8, as shown in Figure 13, is composed of a main body portion 11 and a discolored portion 12. The main body portion 11 is made of a conductive material, specifically pure Cu, and more specifically, Cu plating. The discolored portion 12 is a thin film covering the main body portion 11 and constitutes all four sides 8g to 8j of the pillar portion 8. The discolored portion 12 is made of an oxide of the conductive material that constitutes the main body portion 11, specifically copper oxide (cuprite, cupric oxide, verdigris). The discolored portion 12 can be formed by oxidizing the surface of the main body portion 11, for example, by exposing the wiring portions 8a to 8d that constitute the pillar portion 8 to the atmosphere after plating. The discolored portion 12 has a different color from the main body portion 11. That is, the main body portion 11, made of pure Cu, has a glossy reddish-brown (or reddish metallic luster), while the discolored portion 12, made of copper oxide, has a dark brown, blackish-brown, or verdigris color. The color of the discolored part 12 may be a single color or a mixture of multiple colors (for example, in a mottled pattern), as long as it is different from the color of the main body part 11.

[0044] As described above, the end faces 2a, 2b and sides 2e, 2f of the base body 2 are cut surfaces formed during the individualization process of the coil component 1. If a defect such as misalignment occurs during individualization, it is possible that a portion of the coil conductor 5 may be exposed from one of the end faces 2a, 2b or sides 2e, 2f due to an incorrect cutting angle or position. Figure 14 shows a state in which misalignment has occurred at the end face 2a, and a portion of the pillar portion 8 is exposed from the cut surface when viewed from the end face 2a side. In the exposed pillar portion 8, the discolored portion 12 on the surface has been scraped off by the cutting, exposing the main body portion 11. Therefore, if the end face 2a is observed using a microscope or imaging device, for example, the exposure of the main body portion 11 can be detected, and thus the misalignment can be detected.

[0045] As in the embodiment described above, when the base body 2 is translucent, not only the exposed pillar portion 8 but also the non-exposed pillar portion 8 is visible from the end face 2a side, making it difficult to detect the exposure of the main body portion 11. In the pillar portion 8, the sides 8g to 8j are composed of discolored portions 12 having a different color from the main body portion 11, thereby increasing the color difference between the main body portion 11 and the discolored portions 12. Therefore, even when the base body 2 is translucent, the exposure of the pillar portion 8 from the cut surface can be easily and accurately detected, and as a result, defective products caused by cutting misalignment can be easily and accurately detected. In this specification, "translucent" is not limited to being completely transparent, but also includes, for example, light being transmitted to such an extent that the coil conductor 5 can be seen from the appearance of the base body 2.

[0046] In particular, in the coil component 1, since the coil conductor 5 has a coil axis perpendicular to the stacking direction of the base body 2, the coil conductor 5 contains more portions parallel to the stacking direction compared to a coil conductor with a coil axis parallel to the stacking direction of the base body 2. As a result, when cutting misalignment occurs, the exposed area of ​​the coil conductor 5 exposed from the cut surface tends to be larger. Therefore, the exposure of the pillar portion 8 from the cut surface can be easily and accurately detected, and defective products caused by cutting misalignment can be easily and accurately detected.

[0047] Furthermore, the discolored portion 12 does not necessarily have to constitute all four sides 8g to 8j of the pillar portion 8; it may be configured so that only the sides 8g to 8j that can be exposed during piece formation are composed of the discolored portion 12. For example, in each pillar portion 8 of the first row 8A shown in Figure 12, the side 8g (orientation surface) facing the end face 2a of the base body 2 may be exposed from the end face 2a during piece formation, but the side 8h facing the end face 2b of the base body 2 is not exposed during piece formation. Therefore, in each pillar portion 8 of the first row 8A, only the side 8g may be composed of the discolored portion 12. Similarly, in each pillar portion 8 of the second row 8B, the side 8h (orientation surface) facing the end face 2b of the base body 2 may be exposed from the end face 2b during piece formation, but the side 8g facing the end face 2a of the base body 2 is not exposed during piece formation. Therefore, in each pillar portion 8 of the second row 8B, only the side surface 8h may be composed of the discolored portion 12.

[0048] Furthermore, in the base body 2, not only the end faces 2a and 2b, but also the sides 2e and 2f are cut surfaces. Therefore, the first pillar portion 8 counting from the side 2f side of the multiple pillar portions 8 may have its side 8i (orientation surface) facing the side 2f side of the base body 2 exposed from the side 2f during piece separation. For this reason, the side 8i of this pillar portion 8 may be composed of the discoloration portion 12. Similarly, the fifth pillar portion 8 counting from the side 2f side of the multiple pillar portions 8 may have its side 8j (orientation surface) facing the side 2e side of the base body 2 exposed from the side 2e during piece separation. For this reason, the side 8j of this pillar portion 8 may be composed of the discoloration portion 12.

[0049] Furthermore, similar to the pillar portion 8, the parts of the coil conductor 5 other than the pillar portion 8 may also be configured to include the main body portion 11 and the discoloration portion 12. In this embodiment, both the second wiring portion 6 and the first wiring portion 7 have sides corresponding to the end faces 2a, 2b and sides 2e, 2f of the base body 2, respectively. Therefore, the sides (orientation surfaces) of the second wiring portion 6 and the first wiring portion 7 facing the end faces 2a, 2b or sides 2e, 2f of the base body 2 may be made of the discoloration portion.

[0050] When the base body 2 is translucent as in the embodiment described above, the multiple second wiring portions 6 that constitute a part of the coil conductor 5 are visible when viewed from the main surface 2c side of the base body 2. More specifically, when viewed from the main surface 2c side of the base body 2, the opposing surfaces 6c of each of the multiple second wiring portions 6 are visible, and the colored layer 10 provided on the opposing surfaces 6c is visible.

[0051] As can be seen from the above description, this specification discloses the following: [Note 1] A base body composed of multiple stacked insulating layers, A coil conductor provided within the aforementioned body, having a coil axis perpendicular to the stacking direction of the aforementioned body, Equipped with, A coil component in which the coil conductor has an orientation surface facing the surface side of the base body parallel to the stacking direction, and has a main body portion and a discolored portion having a different color from the main body portion and constituting at least the orientation surface. [Note 2] The coil component described in Appendix 1, wherein the aforementioned body is translucent. [Note 3] The coil component described in Appendix 1 or 2, wherein the main body is made of Cu. [Note 4] The coil component according to any one of the appendices 1 to 3, wherein the discolored portion is composed of an oxide of the material constituting the main body. [Note 5] The aforementioned base body has a mounting surface perpendicular to the stacking direction, The coil component according to any one of the appendices 1 to 4, wherein the coil conductor includes a plurality of first wiring portions extending parallel to the mounting surface of the base body, a plurality of second wiring portions extending parallel to the mounting surface on a side further from the mounting surface than the first wiring portions, and a plurality of pairs of pillar portions extending toward the mounting surface along the stacking direction from both ends of each of the plurality of second wiring portions. [Note 6] The pillar portion has a rectangular cross-sectional shape, The coil component as described in Appendix 5, wherein the discolored portion constitutes an orientation surface in the pillar portion that faces the surface side of the base body parallel to the lamination direction. [Explanation of Symbols]

[0052] 1... Coil component, 2... Base body, 3, 4... Bottom electrodes, 5... Coil conductor, 6... Second wiring section, 7... First wiring section, 8... Pillar section, 8g~8j... Side view, 11... Main body section, 12... Discolored section, 21~29... Base layer, D1... First direction, D2... Second direction, D3... Third direction.

Claims

1. A base body composed of multiple stacked insulating layers, A coil conductor provided within the aforementioned body, having a coil axis perpendicular to the stacking direction of the aforementioned body, Equipped with, A coil component in which the coil conductor has an orientation surface facing the surface side of the base body parallel to the stacking direction, and has a main body portion and a discolored portion having a different color from the main body portion and constituting at least the orientation surface.

2. The coil component according to claim 1, wherein the base material is translucent.

3. The coil component according to claim 1 or 2, wherein the main body is made of Cu.

4. The coil component according to claim 1, wherein the discolored portion is composed of an oxide of the material constituting the main body portion.

5. The aforementioned base body has a mounting surface perpendicular to the stacking direction, The coil component according to claim 1, wherein the coil conductor includes a plurality of first wiring portions extending parallel to the mounting surface of the base body, a plurality of second wiring portions extending parallel to the mounting surface on a side further from the mounting surface than the first wiring portions, and a plurality of pairs of pillar portions extending toward the mounting surface along the stacking direction from both ends of each of the plurality of second wiring portions.

6. The pillar portion has a rectangular cross-sectional shape, The coil component according to claim 5, wherein the discolored portion constitutes an orientation surface in the pillar portion that faces the surface side of the base body parallel to the stacking direction.

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