Manufacturing method of laminated coil component

Abstract

To provide a method for manufacturing a laminated coil component that can prevent the occurrence of malfunctions in coil conductors in a manufacturing process.SOLUTION: A method for manufacturing a laminated coil component 1 includes the steps of: forming a conductor by a photolithography method by using photosensitive conductive paste; forming an insulating film coating the conductor by the photolithography method by using a photosensitive insulating paste; forming a resin layer holding the conductor coated with the insulating film with positive photoresist; after forming a plurality of conductors and insulating films, irradiating the resin layer with ultra violet rays and developing the resin layer to remove the resin layer; and after removing the resin layer, filling the conductors coated with the insulating films with magnetic material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a laminated coil component. [Background technology]

[0002] A known conventional method for manufacturing a laminated coil component is, for example, the method described in Patent Document 1. The method for manufacturing a laminated coil component described in Patent Document 1 is a method for manufacturing a coil component including an element body containing a filler and a resin material, a coil portion composed of a coil conductor embedded in the element body, and a pair of external electrodes electrically connected to the coil conductor, wherein the coil conductor is covered with a glass film, and includes the steps of: using a photolithography method to form a conductor paste layer on a substrate from a photosensitive metal paste containing a metal that constitutes the coil conductor; using a photolithography method to form a glass paste layer so as to cover the conductor paste layer from a photosensitive glass paste containing glass that constitutes the glass film; forming a retaining layer on an area on the substrate where the conductor paste layer and the glass paste layer are not present from a photosensitive paste that is removable after firing; and firing the substrate on which the conductor paste layer, glass paste layer, and retaining layer are formed, thereby forming the coil portion on the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-186525 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional manufacturing methods for laminated coil components, a substrate having a conductor paste layer, a glass paste layer, and a retaining layer formed thereon is fired to form a glass film that covers the coil conductor and the coil, and the retaining layer is removed. However, in conventional manufacturing methods, when the retaining layer is removed by firing, there is a risk that the coil conductor held by the retaining layer may shift or lose its balance due to the effects of binder removal from the photosensitive paste that forms the retaining layer. If a defect occurs in the coil conductor, there is a risk that the reliability of the laminated coil component may decrease and the yield may decrease.

[0005] An object of one aspect of the present invention is to provide a method for manufacturing a laminated coil component that can suppress the occurrence of defects in coil conductors during the manufacturing process. [Means for solving the problem]

[0006] A method for manufacturing a laminated coil component according to one aspect of the present invention is a method for manufacturing a laminated coil component including an element body and a coil disposed within the element body and configured to include a plurality of conductors, and includes the steps of: forming the conductors by photolithography using a photosensitive conductive paste; forming an insulating film that covers the conductors by photolithography using a photosensitive insulating paste; forming a resin layer that holds the conductors covered by the insulating film, using a positive photoresist; after forming the plurality of conductors and the insulating film, irradiating the resin layer with ultraviolet light and developing it to remove the resin layer; and after removing the resin layer, filling the conductors covered by the insulating film with a magnetic material.

[0007] In a method for manufacturing a laminated coil component according to one aspect of the present invention, a resin layer is formed using a positive photoresist, and the resin layer is removed by irradiating it with ultraviolet light and developing it. In this manner, the method for manufacturing a laminated coil component can remove the resin layer without firing. Therefore, the method for manufacturing a laminated coil component can prevent defects from occurring in the coil conductor during the manufacturing process due to binder removal during firing, etc. As a result, the method for manufacturing a laminated coil component can avoid a decrease in the reliability of the laminated coil component and a decrease in yield.

[0008] In one embodiment, the photosensitive insulating paste is a photosensitive glass paste, and a glass film may be formed as the insulating film, which can adequately electrically insulate adjacent coil conductors from each other.

[0009] In one embodiment, the method may include a step of subjecting the conductor and insulating film to a heat treatment after removing the resin layer. In this method, the conductor and insulating film are sintered by the heat treatment before the magnetic material is filled, which further reduces the occurrence of defects in the conductor.

[0010] In one embodiment, the method may include a step of filling the conductor with a magnetic material and then performing a heat treatment. In this method, the resin layer is removed, the conductor is filled with a magnetic material, and then the heat treatment is performed, so that the conductor is held by the magnetic material. Therefore, displacement of the conductor can be further suppressed. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to prevent defects from occurring in the coil conductor during the manufacturing process. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a laminated coil component according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing a cross-sectional configuration of the laminated coil component shown in FIG. [Figure 3]3(a), 3(b), 3(c), 3(d), 3(e), and 3(f) are diagrams illustrating the manufacturing process of the laminated coil component. [Figure 4] 4(a), 4(b), 4(c), 4(d), 4(e), and 4(f) are diagrams illustrating the manufacturing process of the laminated coil component. [Figure 5] 5(a), 5(b), 5(c), 5(d), 5(e), and 5(f) are diagrams illustrating the manufacturing process of the laminated coil component. [Figure 6] FIG. 6 is a perspective view of the laminated coil component according to the second embodiment. [Figure 7] FIG. 7 is a diagram showing a cross-sectional configuration of the laminated coil component shown in FIG. [Figure 8] 8(a), 8(b), 8(c), 8(d), 8(e), and 8(f) are diagrams illustrating the manufacturing process of the laminated coil component. [Figure 9] 9(a), 9(b), 9(c), 9(d), 9(e), and 9(f) are diagrams illustrating the manufacturing process of the laminated coil component. [Figure 10] 10(a), 10(b), 10(c), 10(d), 10(e), and 10(f) are diagrams illustrating the manufacturing process of the laminated coil component. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted.

[0014] [First embodiment] A laminated coil component according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view of the laminated coil component according to the first embodiment. Fig. 2 is a view showing a cross-sectional configuration of the laminated coil component shown in Fig. 1. As shown in Figs. 1 and 2, the laminated coil component 1 includes an element body 2, a first terminal electrode 3, a second terminal electrode 4, a coil 5, and a covering portion 6.

[0015] The element body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 has, as its outer surfaces, end faces 2a and 2b, main faces 2c and 2d, and 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 facing direction of the main faces 2c and 2d is referred to as a first direction D1, the facing direction of the end faces 2a and 2b is referred to as a second direction D2, and the facing direction of the side faces 2e and 2f is referred to as a third direction D3. The first direction D1, the second direction D2, and the third direction D3 are approximately perpendicular to each other.

[0016] The end faces 2a, 2b extend in the first direction D1 to connect the principal faces 2c, 2d. The end faces 2a, 2b also extend in the third direction D3 to connect the side faces 2e, 2f. The principal faces 2c, 2d extend in the second direction D2 to connect the end faces 2a, 2b. The principal faces 2c, 2d also extend in the third direction D3 to connect the side faces 2e, 2f. The side faces 2e, 2f extend in the first direction D1 to connect the principal faces 2c, 2d. The side faces 2e, 2f also extend in the second direction D2 to connect the end faces 2a, 2b.

[0017] The main surface 2d is a mounting surface that faces another electronic device (not shown) when the laminated coil component 1 is mounted on the other electronic device (for example, a circuit board or a laminated electronic component). The end surfaces 2a and 2b are surfaces that are continuous with the mounting surface (i.e., the main surface 2d).

[0018] In this embodiment, the length of the element body 2 in the second direction D2 is longer than the length of the element body 2 in the third direction D3 and the length of the element body 2 in the first direction D1. The length of the element body 2 in the third direction D3 and the length of the element body 2 in the first direction D1 are, for example, equal to each other. That is, in this embodiment, the end faces 2a and 2b are square-shaped, and the main faces 2c and 2d and the side faces 2e and 2f are rectangular-shaped. The length of the element body 2 in the second direction D2 may be equal to or shorter than the length of the element body 2 in the third direction D3 and the length of the element body 2 in the first direction D1. The length of the element body 2 in the third direction D3 and the length of the element body 2 in the first direction D1 may be different from each other.

[0019] In this embodiment, "equivalent" does not only mean equal, but also may mean values that include slight differences or manufacturing errors within a preset range. For example, if multiple values are within a range of ±5% of the average value of the multiple values, the multiple values are defined as equivalent.

[0020] A first recess 7 and a second recess 8 are provided on the outer surface of the element body 2. Specifically, the first recess 7 is provided on the end face 2a and is recessed toward the end face 2b. The second recess 8 is provided on the end face 2b and is recessed toward the end face 2a.

[0021] The element body 2 is made of, for example, a magnetic material (such as a Ni-Cu-Zn ferrite material, a Ni-Cu-Zn-Mg ferrite material, or a Ni-Cu ferrite material.) The magnetic material making up the element body 2 may include an Fe alloy.

[0022] The first terminal electrode 3 is arranged on the end face 2a side of the element body 2. The second terminal electrode 4 is arranged on the end face 2b side of the element body 2. The first terminal electrode 3 and the second terminal electrode 4 are spaced apart from each other in the second direction D2. The first terminal electrode 3 is arranged in the first recess 7. The second terminal electrode 4 is arranged in the second recess 8. The first terminal electrode 3 is arranged across the end face 2a and the main face 2d. The second terminal electrode 4 is arranged across the end face 2b and the main face 2d. In this embodiment, the surface of the first terminal electrode 3 is approximately flush with each of the end face 2a and the main face 2d. The surface of the second terminal electrode 4 is approximately flush with each of the end face 2b and the main face 2d. The first terminal electrode 3 and the second terminal electrode 4 are made of a conductive material (for example, Ag and / or Pd).

[0023] The first terminal electrode 3 has an L-shape when viewed from the third direction D3. The first terminal electrode 3 has a plurality of electrode portions 3a, 3b. The electrode portions 3a and 3b are connected at the ridge portion of the element body 2 and are electrically connected to each other. In this embodiment, the electrode portions 3a and 3b are integrally formed. The electrode portion 3a extends along the first direction D1. The electrode portion 3a has a rectangular shape when viewed from the second direction D2. The electrode portion 3b extends along the second direction D2. The electrode portion 3b has a rectangular shape when viewed from the first direction D1. Each of the electrode portions 3a and 3b extends along the third direction D3.

[0024] The first terminal electrode 3 is formed by stacking a plurality of first electrode layers 20, 21, 22, 23, 24, 25, 26 (see FIG. 5(e)) in a first direction D1. That is, the stacking direction of the first electrode layers 20 to 26 is the first direction D1. In the actual first terminal electrode 3, the plurality of first electrode layers 20 to 26 are integrated to the extent that the boundaries between the layers are not visible.

[0025] The second terminal electrode 4 has an L-shape when viewed from the third direction D3. The second terminal electrode 4 has a plurality of electrode portions 4a, 4b. The electrode portions 4a and 4b are connected at the ridge portion of the element body 2 and are electrically connected to each other. In this embodiment, the electrode portions 4a and 4b are integrally formed. The electrode portion 4a extends along the first direction D1. The electrode portion 4a has a rectangular shape when viewed from the second direction D2. The electrode portion 4b extends along the second direction D2. The electrode portion 4b has a rectangular shape when viewed from the first direction D1. Each of the electrode portions 4a and 4b extends along the third direction D3.

[0026] The second terminal electrode 4 is formed by stacking a plurality of second electrode layers 30, 31, 32, 33, 34, 35, and 36 (see FIG. 5(e)) in a first direction D1. That is, the stacking direction of the second electrode layers 30 to 36 is the first direction D1. In the actual second terminal electrode 4, the plurality of second electrode layers 30 to 36 are integrated to the extent that the boundaries between the layers are not visible.

[0027] A plating layer (not shown) containing, for example, Ni, Sn, Au, etc. may be provided on the first terminal electrode 3 and the second terminal electrode 4 by electrolytic plating or electroless plating. The plating layer may have, for example, a Ni plating film containing Ni and covering the first terminal electrode 3 and the second terminal electrode 4, and an Au plating film containing Au and covering the Ni plating film.

[0028] The coil 5 is disposed within the element body 2. One end of the coil 5 is connected to the first terminal electrode 3 via a connecting conductor 48. The other end of the coil 5 is connected to the second terminal electrode 4 via a connecting conductor 49. The coil 5 is configured to include a plurality of coil conductors 40, 41, 42, 43, 44, 45, and 46 (see FIG. 5(e)). The plurality of coil conductors 40 to 46 are connected to one another to form the coil 5. The coil axis of the coil 5 is provided along the first direction D1. The coil conductors 40 to 46 are arranged so that at least a portion of them overlap one another when viewed from the first direction D1. The coil conductors 40 to 46 are arranged spaced apart from the end faces 2a and 2b, the main faces 2c and 2d, and the side faces 2e and 2f. The coil 5 is made of a conductive material (for example, Ag and / or Pd).

[0029] The covering portion 6 covers the coil 5. The covering portion 6 is configured to include glass films (insulating films) 60, 61, 62, 63, 64, 65, and 66 (see FIG. 5(e)). The covering portion 6 is made of glass.

[0030] Next, an example of a method for manufacturing the laminated coil component 1 will be described with reference to Fig. 3, Fig. 4, and Fig. 5. Fig. 3(a) to Fig. 3(f), Fig. 4(a) to Fig. 4(f), and Fig. 5(a) to Fig. 5(f) show plan views and / or cross-sectional views in the manufacturing process. In this embodiment, the laminated coil component 1 is manufactured using a photolithography method. The "photolithography method" in this embodiment is not limited to a specific type of mask, as long as it is a method for processing a layer containing a photosensitive material into a desired pattern by exposing and developing the layer.

[0031] As shown in FIG. 3( a), a first electrode layer 20, a second electrode layer 30, a coil conductor 40, and a connecting conductor 48 are formed on a magnetic substrate 10. The first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48 are formed using photolithography. Specifically, a photosensitive silver paste (photosensitive conductive paste) is applied to the magnetic substrate 10. Next, the photosensitive silver paste is exposed to ultraviolet light through a mask (e.g., a Cr mask) having the patterns of the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48, and then developed with a developer to form the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48. The first electrode layer 20 and the coil conductor 40 are electrically connected by the connecting conductor 48. Subsequently, the first electrode layers 21 to 26, the second electrode layers 31 to 36, the coil conductors 41 to 46, and the connecting conductor 49 are formed using a method similar to the photolithography method described above.

[0032] Next, as shown in FIG. 3( b), a retaining layer (resin layer) 50 is formed. The retaining layer 50 retains the coil conductor 40. The retaining layer 50 is a positive photoresist. The retaining layer 50 is formed using a photolithography method. Specifically, a resin paste forming a positive photoresist is applied to the magnetic material substrate 10, the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48. Next, the resin paste is exposed to ultraviolet light through a mask having patterns of the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48, and then developed with a developer to form the retaining layer 50. The mask has a pattern wider than the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48 so that gaps are formed between the retaining layer 50 and the first electrode layer 20, the second electrode layer 30, the coil conductor 40, and the connecting conductor 48. Thereafter, the retention layers 51 to 56 are formed by a method similar to the above-mentioned photolithography method.

[0033] Next, as shown in FIG. 3( c), a glass film (insulating layer) 60 is formed. The glass film 60 is formed using photolithography. Specifically, a photosensitive glass paste is applied to the first electrode layer 20, the second electrode layer 30, the coil conductor 40, the connection conductor 48, and the retainer layer 50. This fills the gaps between the first electrode layer 20, the second electrode layer 30, the coil conductor 40, the connection conductor 48, and the retainer layer 50 with the photosensitive glass paste. Next, the photosensitive glass paste is exposed to ultraviolet light through a mask that exposes portions of the first electrode layer 20, the second electrode layer 30, and the coil conductor 40, and is developed with a developer to form the glass film 60. The glass film 60 exposes portions of the first electrode layer 20, the second electrode layer 30, and the coil conductor 40. The glass film 60 covers the coil conductor 40. Specifically, the glass film 60 covers the side and top surfaces of the coil conductor 40, leaving a portion of the top surface exposed. Thereafter, glass films 61 to 66 are formed by the same method as the above-mentioned photolithography method.

[0034] Next, as shown in FIG. 3(d), a first electrode layer 21, a second electrode layer 31, and a coil conductor 41 are formed. The first electrode layer 21 is formed on the first electrode layer 20. The first electrode layer 21 is electrically connected to the first electrode layer 20. The second electrode layer 31 is formed on the second electrode layer 30. The second electrode layer 31 is electrically connected to the second electrode layer 32. The coil conductor 41 is formed on a portion of the coil conductor 40. The coil conductor 41 is electrically connected to the coil conductor 40. Next, as shown in FIG. 3(e), a retaining layer 51 is formed. The retaining layer 51 is formed on the retaining layer 50. Next, as shown in FIG. 3(f), a glass film 61 is formed. The glass film 61 exposes the first electrode layer 21, the second electrode layer 31, and a portion of the coil conductor 41.

[0035] Next, as shown in FIG. 4( a), a first electrode layer 22, a second electrode layer 32, and a coil conductor 42 are formed. The first electrode layer 22 is formed on the first electrode layer 21. The first electrode layer 22 is electrically connected to the first electrode layer 21. The second electrode layer 32 is formed on the second electrode layer 31. The second electrode layer 32 is electrically connected to the second electrode layer 31. The coil conductor 42 is formed on a portion of the coil conductor 41. The coil conductor 42 is electrically connected to the coil conductor 41. Next, as shown in FIG. 4( b), a support layer 52 is formed. The support layer 52 is formed on the support layer 51. Next, as shown in FIG. 4( c), a glass film 62 is formed. The glass film 62 exposes the first electrode layer 22, the second electrode layer 32, and a portion of the coil conductor 42.

[0036] Next, as shown in FIG. 4(d), a first electrode layer 23, a second electrode layer 33, and a coil conductor 43 are formed. The first electrode layer 23 is formed on the first electrode layer 22. The first electrode layer 23 is electrically connected to the first electrode layer 22. The second electrode layer 33 is formed on the second electrode layer 32. The second electrode layer 33 is electrically connected to the second electrode layer 32. The coil conductor 43 is formed on a portion of the coil conductor 42. The coil conductor 43 is electrically connected to the coil conductor 42. Next, as shown in FIG. 4(e), a retaining layer 53 is formed. The retaining layer 53 is formed on the retaining layer 52. Next, as shown in FIG. 4(f), a glass film 63 is formed. The glass film 63 exposes the first electrode layer 23, the second electrode layer 33, and a portion of the coil conductor 43.

[0037] Next, as shown in FIG. 5(a), a first electrode layer 24 and a first electrode layer 25 are formed. The first electrode layer 24 is formed on the first electrode layer 23. The first electrode layer 25 is formed on the first electrode layer 24. Furthermore, a second electrode layer 34 and a second electrode layer 35 are formed. The second electrode layer 34 is formed on the second electrode layer 33. The second electrode layer 35 is formed on the second electrode layer 34.

[0038] Furthermore, the coil conductor 44 and the coil conductor 45 are formed. The coil conductor 44 is formed on a part of the coil conductor 43. The coil conductor 45 is formed on a part of the coil conductor 44.

[0039] Furthermore, retaining layers 54 and 55 are formed. Retaining layer 54 is formed on retaining layer 53. Retaining layer 55 is formed on retaining layer 54. Furthermore, glass films 64 and 65 are formed. Glass film 64 is formed on glass film 63. Glass film 65 is formed on glass film 64.

[0040] 5(b), the first electrode layer 26, the second electrode layer 36, the coil conductor 46, and the connecting conductor 49 are formed. The first electrode layer 26 is formed on the first electrode layer 25. The second electrode layer 36 is formed on the second electrode layer 35. The coil conductor 46 is formed on a portion of the coil conductor 45. The second electrode layer 36 and the coil conductor 46 are electrically connected by the connecting conductor 49.

[0041] Next, as shown in Fig. 5(c), a retaining layer 56 is formed. The retaining layer 56 is formed on the retaining layer 55. Next, as shown in Fig. 5(d), a glass film 66 is formed. The glass film 66 covers the first electrode layer 26, the second electrode layer 36, the coil conductor 46, and the connecting conductor 49.

[0042] 5(e), the retention layers 50-56 are exposed to ultraviolet light and developed with a developer to remove the retention layers 50-56. Subsequently, the coil conductors 40-46 coated with the first electrode layers 20-26, second electrode layers 30-36, and glass films 60-66 are subjected to a heat treatment. Specifically, the heat treatment is performed at a temperature of 650°C to 950°C, for example.

[0043] Next, as shown in FIG. 5(f), the coil conductors 40-46 coated with the glass films 60-66 are filled with a magnetic material 70. Subsequently, the magnetic material 70 is heat-treated to sinter the magnetic material, thereby forming the element body 2. In this manner, the laminated coil component 1 is obtained. If necessary, after the heat treatment, the first terminal electrode 3 and the second terminal electrode 4 may be subjected to electrolytic plating or electroless plating to provide a plating layer.

[0044] As described above, in the method for manufacturing the laminated coil component 1 according to this embodiment, the retaining layers 50-56 are formed using a positive photoresist, and the retaining layers 50-56 are exposed to ultraviolet light and developed with a developer to remove the retaining layers 50-56. In this way, in the method for manufacturing the laminated coil component 1, the retaining layers 50-56 can be removed without firing. Therefore, in the method for manufacturing the laminated coil component 1, defects in the coil conductors 40-46 caused by binder removal during firing or the like can be suppressed during the manufacturing process. As a result, in the method for manufacturing the laminated coil component 1, a decrease in the reliability of the laminated coil component 1 and a decrease in yield can be avoided.

[0045] Furthermore, in the manufacturing method of the laminated coil component 1, the coil conductors 40 to 46 are covered with the glass films 60 to 66, thereby ensuring the insulation of the coil conductors 40 to 46. This allows the thickness of the glass films 60 to 66 to be reduced, thereby shortening the distance between the coil conductors 40 to 46. In other words, the inter-conductor layers of the coil conductors 40 to 46 can be made thinner. As a result, the laminated coil component 1 can be made smaller and its characteristics can be improved.

[0046] In the laminated coil component 1 according to this embodiment, the photosensitive insulating paste is a photosensitive glass paste, and forms glass films 60 to 66 as insulating films. This method can appropriately electrically insulate the adjacent coil conductors 40 to 46 from each other.

[0047] In the laminated coil component 1 according to this embodiment, after removing the support layers 50-56, the coil conductors 40-46 and the glass films 60-66 are subjected to a heat treatment. Then, the magnetic material 70 is filled. In this method, the coil conductors 40-46 and the glass films 60-66 are sintered by heat treatment, and then the magnetic material 70 is filled, which further prevents defects from occurring in the coil conductors 40-46.

[0048] [Second embodiment] Next, a laminated coil component according to a second embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a perspective view of the laminated coil component according to the second embodiment. Fig. 7 is a view showing a cross-sectional configuration of the laminated coil component shown in Fig. 6. As shown in Fig. 6 and Fig. 7, the laminated coil component 1A includes an element body 2, a first terminal electrode 3A, a second terminal electrode 4A, a coil 5A, and a covering portion 6A.

[0049] The first terminal electrode 3A is disposed on the end surface 2a of the element body 2, and the second terminal electrode 4A is disposed on the end surface 2b of the element body 2. That is, the first terminal electrode 3A and the second terminal electrode 4A are spaced apart from each other in the second direction D2. The first terminal electrode 3A and the second terminal electrode 4A have a substantially rectangular shape in a plan view, and the corners of the first terminal electrode 3A and the second terminal electrode 4A are rounded. The first terminal electrode 3A and the second terminal electrode 4A contain a conductive material. The conductive material is, for example, Ag or Pd. The first terminal electrode 3A and the second terminal electrode 4A are configured as a sintered body of a conductive paste. The conductive paste contains a conductive metal powder and a glass frit. The conductive metal powder is, for example, Ag powder and / or Pd powder.

[0050] The first terminal electrode 3A includes five electrode portions: an electrode portion 3Aa located on the end face 2a, an electrode portion 3Ab located on the main face 2d, an electrode portion 3Ac located on the main face 2c, an electrode portion 3Ad located on the side face 2e, and an electrode portion 3Ae located on the side face 2f. The electrode portion 3Aa covers the entire end face 2a. The electrode portion 3Ab covers a portion of the main face 2d. The electrode portion 3Ac covers a portion of the main face 2c. The electrode portion 3Ad covers a portion of the side face 2e. The electrode portion 3Ae covers a portion of the side face 2f. The five electrode portions 3Aa, 3Ab, 3Ac, 3Ad, and 3Ae are integrally formed.

[0051] The second terminal electrode 4A includes five electrode portions: an electrode portion 4Aa located on the end face 2b, an electrode portion 4Ab located on the main face 2d, an electrode portion 4Ac located on the main face 2c, an electrode portion 4Ad located on the side face 2e, and an electrode portion 4Ae located on the side face 2f. The electrode portion 4Aa covers the entire end face 2b. The electrode portion 4Ab covers a portion of the main face 2d. The electrode portion 4Ac covers a portion of the main face 2c. The electrode portion 4Ad covers a portion of the side face 2e. The electrode portion 4Ae covers a portion of the side face 2f. The five electrode portions 4Aa, 4Ab, 4Ac, 4Ad, and 4Ae are integrally formed.

[0052] The coil 5A is disposed within the element body 2. One end of the coil 5A is connected to the first terminal electrode 3A via a connecting conductor 88. The other end of the coil 5A is connected to the second terminal electrode 4A via a connecting conductor 89. The coil 5A includes a plurality of coil conductors 80, 81, 82, 83, 84, 85, and 86 (see FIG. 10(e)). The plurality of coil conductors 80 to 86 are connected to one another to form the coil 5A. The coil axis of the coil 5A is provided along the first direction D1. The coil conductors 80 to 86 are arranged so that at least a portion of each of them overlaps with one another when viewed from the first direction D1. The coil conductors 80 to 86 are arranged spaced apart from the end faces 2a and 2b, the main faces 2c and 2d, and the side faces 2e and 2f. The coil 5A is made of a conductive material (for example, Ag and / or Pd).

[0053] The covering portion 6A covers the coil 5A. The covering portion 6A is configured to include glass films 100, 101, 102, 103, 104, 105, and 106 (see FIG. 10(e)). The covering portion 6A is made of glass.

[0054] Next, an example of a method for manufacturing the laminated coil component 1A will be described with reference to Figures 8, 9, and 10. Figures 8(a) to 8(f), 9(a) to 9(f), and 10(a) to 10(f) show plan views and / or cross-sectional views of the manufacturing process.

[0055] As shown in FIG. 8(a), a coil conductor 80 and a connecting conductor 88 are formed on a magnetic material substrate 11. The coil conductor 80 and the connecting conductor 88 are formed using a photolithography method. Specifically, a photosensitive silver paste (photosensitive conductive paste) is applied to the magnetic material substrate 11. Next, the photosensitive silver paste is exposed to ultraviolet light through a mask (for example, a Cr mask) having the patterns of the coil conductor 80 and the connecting conductor 88, and then developed with a developer, thereby forming the coil conductor 80 and the connecting conductor 88. The connecting conductor 48 electrically connects the coil conductor 80 and the first terminal electrode 3. Thereafter, the coil conductors 81 to 86 and the connecting conductor 89 are formed using a method similar to the photolithography method described above.

[0056] Next, as shown in FIG. 8(b), a retention layer 90 is formed. The retention layer 90 retains the coil conductor 80. The retention layer 90 is a positive photoresist. The retention layer 90 is formed using a photolithography method. Specifically, a resin paste that forms a positive photoresist is applied to the magnetic material substrate 11, the coil conductor 80, and the connection conductor 88. Next, the resin paste is exposed to ultraviolet light through a mask having the patterns of the coil conductor 80 and the connection conductor 88, and then developed with a developer to form the retention layer 90. The mask has a pattern that is wider than the coil conductor 80 and the connection conductor 88 so that gaps are formed between the coil conductor 80 and the connection conductor 88 and the retention layer 90. Thereafter, retention layers 91 to 96 are formed using a method similar to the photolithography method described above.

[0057] Next, as shown in FIG. 8(c), a glass film 100 is formed. The glass film 100 is formed using photolithography. Specifically, a photosensitive glass paste is applied onto the coil conductor 80, the connecting conductor 88, and the retaining layer 90. As a result, the photosensitive glass paste fills the gaps between the coil conductor 80, the connecting conductor 88, and the retaining layer 90. Next, the photosensitive glass paste is exposed to ultraviolet light through a mask that exposes a portion of the coil conductor 80, and is developed with a developer to form the glass film 100. The glass film 100 exposes a portion of the coil conductor 80. The glass film 100 covers the coil conductor 80. Specifically, the glass film 100 covers the side and top surfaces of the coil conductor 80, leaving a portion of the top surface exposed. Thereafter, the glass films 101 to 106 are formed using a method similar to the photolithography method described above.

[0058] Next, as shown in FIG. 8(d), a coil conductor 81 is formed. The coil conductor 81 is formed on a portion of the coil conductor 80. The coil conductor 81 is electrically connected to the coil conductor 80. Next, as shown in FIG. 8(e), a support layer 91 is formed. The support layer 91 is formed on the support layer 90. Next, as shown in FIG. 8(f), a glass film 101 is formed. The glass film 101 exposes a portion of the coil conductor 81.

[0059] Next, as shown in FIG. 9(a), a coil conductor 82 is formed. The coil conductor 82 is formed on a portion of the coil conductor 81. The coil conductor 82 is electrically connected to the coil conductor 81. Next, as shown in FIG. 9(b), a support layer 92 is formed. The support layer 92 is formed on the support layer 91. Next, as shown in FIG. 9(c), a glass film 102 is formed. The glass film 102 exposes a portion of the coil conductor 82.

[0060] Next, as shown in FIG. 9(d), a coil conductor 83 is formed. The coil conductor 83 is formed on a portion of the coil conductor 82. The coil conductor 83 is electrically connected to the coil conductor 82. Next, as shown in FIG. 8(e), a support layer 93 is formed. The support layer 93 is formed on the support layer 92. Next, as shown in FIG. 8(f), a glass film 103 is formed. The glass film 103 exposes a portion of the coil conductor 83.

[0061] Next, as shown in FIG. 10(a), coil conductor 84 and coil conductor 85 are formed. Coil conductor 84 is formed on a portion of coil conductor 83. Coil conductor 85 is formed on a portion of coil conductor 84. Furthermore, retaining layer 94 and retaining layer 95 are formed. Retaining layer 94 is formed on retaining layer 93. Retaining layer 95 is formed on retaining layer 94. Furthermore, glass film 104 and glass film 105 are formed. Glass film 104 is formed on glass film 103. Glass film 105 is formed on glass film 104.

[0062] 10(b), a coil conductor 86 and a connecting conductor 89 are formed. The coil conductor 86 is formed on a part of the coil conductor 85. The connecting conductor 89 electrically connects the coil conductor 86 and the second terminal electrode 4.

[0063] Next, as shown in Fig. 10(c), a support layer 96 is formed. The support layer 96 is formed on the support layer 95. Next, as shown in Fig. 10(d), a glass film 106 is formed. The glass film 106 covers the coil conductor 86.

[0064] 10(e), the protective layers 90-96 are exposed to ultraviolet light and developed with a developer to remove the protective layers 90-96. Subsequently, the coil conductors 80-86 coated with the glass films 100-106 are subjected to a heat treatment. Specifically, the heat treatment is performed at a temperature of 650°C to 950°C, for example.

[0065] Next, as shown in FIG. 10(f), the coil conductors 80-86 coated with the glass films 100-106 are filled with a magnetic material 110. Subsequently, the magnetic material 110 is heat-treated to sinter the magnetic material, thereby forming the element body 2. Next, the first terminal electrodes 3A and the second terminal electrodes 4A are formed. The first terminal electrodes 3A and the second terminal electrodes 4A are formed by applying a conductive paste and firing the conductive paste. In this manner, the laminated coil component 1A is obtained. If necessary, after the heat treatment, the first terminal electrodes 3A and the second terminal electrodes 4A may be subjected to electrolytic plating or electroless plating to provide a plating layer.

[0066] As described above, in the method for manufacturing the laminated coil component 1A according to this embodiment, the retaining layers 90-96 are formed using a positive photoresist, and the retaining layers 90-96 are exposed to ultraviolet light and developed with a developer to remove the retaining layers 90-96. In this way, in the method for manufacturing the laminated coil component 1A, the retaining layers 90-96 can be removed without firing. Therefore, in the method for manufacturing the laminated coil component 1A, defects in the coil conductors 80-86 caused by binder removal during firing or the like can be suppressed during the manufacturing process. As a result, in the method for manufacturing the laminated coil component 1A, a decrease in the reliability of the laminated coil component 1A and a decrease in yield can be avoided.

[0067] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0068] In the above embodiment, a photosensitive glass paste is used as the photosensitive insulating paste, but the photosensitive insulating paste may contain other materials.

[0069] In the above embodiment, the coil conductors 40-46, 80-86 and glass films 60-66, 100-106 are heat-treated after the retention layers 50-56, 90-96 are removed, and then filled with the magnetic material 70, 110. However, the retention layers 50-56, 90-96 may be removed, and then filled with the magnetic material 70, 110, and then heat-treated.

[0070] In the above embodiment, an example has been described in which heat treatment is performed after filling with the magnetic materials 70, 110. However, if the magnetic materials 70, 110 are metallic magnetic materials or the like, heat treatment may not be performed.

[0071] In the above embodiment, the coils 5, 5A have been described as having the coil conductors 40 to 46, 80 to 86. However, the number of coil conductors is not limited to the above values. [Explanation of symbols]

[0072] 1, 1A... multilayer coil component, 2... element body, 40 to 46, 80 to 86... coil conductor (conductor), 50 to 56, 90 to 96... retention layer (resin layer), 60 to 66, 100 to 106... glass film (insulating film), 70, 110... magnetic material.

Claims

1. The base body and a coil disposed within the element body and configured to include a plurality of conductors, forming the conductor by photolithography using a photosensitive conductive paste; forming an insulating film covering the conductor by photolithography using a photosensitive insulating paste; forming a resin layer using a positive photoresist to hold the conductor covered with the insulating film; a step of irradiating the resin layer with ultraviolet light and developing the resin layer after forming the plurality of conductors and the insulating film, and removing the resin layer; and then removing the resin layer, filling the conductor covered with the insulating film with a magnetic material.

2. 2. The method for manufacturing a laminated coil component according to claim 1, wherein the photosensitive insulating paste is a photosensitive glass paste, and a glass film is formed as the insulating film.

3. 3. The method for manufacturing a laminated coil component according to claim 1, further comprising the step of: after removing the resin layer, subjecting the conductor and the insulating film to a heat treatment.

4. 3. The method for manufacturing a laminated coil component according to claim 1, further comprising the step of carrying out a heat treatment after filling the magnetic material.

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