Coil component and method of manufacturing the same

Abstract

The present invention relates to a coil component and a method for manufacturing the same. The present invention provides a coil component and a method for manufacturing the same that can alleviate stress generated between a coil wiring and a magnetic layer and stabilize the position of the coil. The coil component includes a substrate and a coil disposed in the substrate, the substrate having a plurality of magnetic layers stacked in a first direction, the coil having a plurality of coil wirings stacked in the first direction, the substrate also having a crack generating layer that overlaps at least a portion of the coil wiring when viewed from the first direction, and a crack existing inside the crack generating layer.

Description

Technical Field

[0001] The present invention relates to a coil component and a method for manufacturing the same. Background Art

[0002] As a conventional coil component, there is a coil component described in Japanese Patent Publication No. 11-219821 (Patent Document 1). The coil component comprises a laminate and a coil disposed in the laminate, wherein the laminate has a plurality of laminated magnetic layers, and the coil has a plurality of laminated conductor layers. Furthermore, a gap is provided between the magnetic layer and the conductor layer, so that the magnetic layer and the conductor layer do not contact each other, thereby relieving the stress generated between the magnetic layer and the conductor layer.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 11-219821

[0004] However, in the above-mentioned conventional coil component, since the gap is provided over the entire circumference of the conductor layer, the conductor layer and the magnetic layer are not in direct contact, and there is a possibility that the position of the conductor layer, that is, the position of the coil, may be unstable. Summary of the invention

[0005] To this end, the present disclosure provides a coil component and a method for manufacturing the same, which can relax stress generated between a coil wiring and a magnetic layer and can stabilize the position of a coil.

[0006] In order to solve the above-mentioned problems, the coil component of the present invention comprises:

[0007] matrix, and

[0008] The coil is arranged in the base body.

[0009] The substrate has a plurality of magnetic layers stacked in a first direction,

[0010] The coil has a plurality of coil wirings stacked in a first direction,

[0011] The base body further includes a crack inducing layer overlapping at least a portion of the coil wiring when viewed from the first direction,

[0012] Cracks exist inside the crack generating layer.

[0013] According to the coil component of the present invention, cracks exist inside the crack generating layer, so stress generated between the coil wiring and the magnetic layer can be relieved. In addition, the coil wiring is stacked on the magnetic layer or the crack generating layer, so the position of the coil wiring, that is, the position of the coil is stable.

[0014] In one embodiment of the coil component, the crack generating layer exists between the magnetic layer and the coil wiring adjacent to each other in the first direction.

[0015] According to the above embodiment, strong stress is generated in the boundary portion between the magnetic layer and the coil wiring adjacent to each other in the first direction. However, by providing the crack inducing layer in the boundary portion, the stress can be effectively relaxed.

[0016] In one embodiment of the coil component, the crack inducing layer exists between two coil wirings adjacent to each other in the first direction.

[0017] According to the above embodiment, stress generated between two coil wirings adjacent to each other in the first direction can be effectively alleviated.

[0018] In one embodiment of the coil component, the crack generating layer exists between two magnetic layers adjacent to each other in the first direction.

[0019] According to the above embodiment, the crack inducing layer can be provided more easily than in the case where the crack inducing layer is provided directly on the coil wiring.

[0020] In one embodiment of the coil component, the crack generating layer is further present between the magnetic layer and the coil wiring adjacent to each other in a direction perpendicular to the first direction.

[0021] According to the above embodiment, stress in the direction orthogonal to the first direction can be alleviated.

[0022] In addition, in one embodiment of the coil component,

[0023] The coil wiring extends along a plane orthogonal to the first direction,

[0024] The coil wiring has two side surfaces on both sides of a direction perpendicular to the first direction in a cross section perpendicular to the extending direction of the coil wiring.

[0025] The crack-generating layer exists between the magnetic layer and the side surface of the coil wiring.

[0026] According to the above embodiment, it is possible to alleviate stress generated between the magnetic layer and the side surfaces of the coil wiring.

[0027] In one embodiment of the coil component, the crack inducing layer has an average thickness of 10 μm or less.

[0028] Here, the average thickness of the crack inducing layer refers to the average thickness of the crack inducing layer in a cross section perpendicular to the extending direction of the coil wiring.

[0029] According to the above embodiment, the crack initiation layer is thin, and therefore, when the crack initiation layer does not have magnetism, good characteristics (high inductance value or high impedance value) can be obtained as a coil component.

[0030] Furthermore, in one embodiment of the coil component, the crack generating layer includes glass having low toughness.

[0031] Here, low toughness means that "low toughness means that the viscosity of the material is low" and "it is easy to break by overcoming external forces. In other words, the crack progresses quickly, the ultimate strength is low, and the plasticity and ductility are low."

[0032] According to the above embodiment, cracks can be reliably generated in the crack-generating layer.

[0033] In one embodiment of the coil component, the crack induction layer has a magnetic permeability greater than 1.

[0034] According to the above-described embodiment, good characteristics (high inductance value or high impedance value) can be obtained as a coil component.

[0035] Furthermore, in one embodiment of the coil component, the magnetic permeability of the crack induction layer is equal to or less than the magnetic permeability of the magnetic layer.

[0036] According to the above-described embodiment, desired characteristics can be obtained as a coil component.

[0037] In one embodiment of the method for manufacturing a coil component, the method includes:

[0038] A preparation step of preparing an unfired magnetic layer, an unfired crack generating layer, and an unfired coil wiring;

[0039] a laminating step of laminating the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring in a first direction so that the unfired crack generating layer overlaps at least a portion of the unfired coil wiring when viewed from the first direction;

[0040] a firing step of firing the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring to obtain a substrate having the magnetic layer and the crack generating layer overlapping at least a portion of the coil wiring when viewed from a first direction, and to obtain a coil provided inside the substrate and having the coil wiring; and

[0041] The crack generating step generates cracks inside the crack generating layer.

[0042] Here, the unfired magnetic layer is composed of, for example, a magnetic sheet or a magnetic paste. The unfired coil wiring is composed of, for example, a conductive paste. The unfired crack-generating layer is composed of, for example, a conductive paste containing glass.

[0043] According to the above embodiment, cracks are generated inside the crack generating layer, so that stress generated between the coil wiring and the magnetic layer can be relieved. In addition, since the coil wiring is stacked on the magnetic layer or the crack generating layer, the position of the coil wiring, that is, the position of the coil is stable.

[0044] In one embodiment of the method for manufacturing a coil component, the crack generating step is a step of subjecting the base body to a thermal shock treatment with a temperature difference of 120° C. or more one or more times.

[0045] According to the above embodiment, cracks can be reliably generated inside the crack generating layer.

[0046] In one embodiment of the method for manufacturing a coil component, the thermal shock treatment is a treatment of immersing the base body in liquid nitrogen one or more times.

[0047] According to the above embodiment, cracks can be generated inside the crack-generating layer by a simple method of immersion.

[0048] In one embodiment of the method for manufacturing a coil component, the method includes:

[0049] A preparation step of preparing an unfired magnetic layer, an unfired crack generating layer, and an unfired coil wiring;

[0050] a laminating step of laminating the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring in a first direction so that the unfired crack generating layer overlaps with at least a portion of the unfired coil wiring when viewed from the first direction; and

[0051] a firing step of firing the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring to obtain a substrate having the magnetic layer and the crack generating layer overlapping at least a portion of the coil wiring when viewed from a first direction, and obtaining a coil provided inside the substrate and having the coil wiring,

[0052] The firing step further includes a step of performing a thermal shock treatment at a firing temperature of 300° C. by opening the layer to the atmosphere to generate cracks inside the crack generating layer.

[0053] Here, the unfired magnetic layer is composed of, for example, a magnetic sheet or a magnetic paste. The unfired coil wiring is composed of, for example, a conductive paste. The unfired crack-generating layer is composed of, for example, a conductive paste containing glass.

[0054] According to the above embodiment, cracks are generated inside the crack generating layer, so that stress generated between the coil wiring and the magnetic layer can be relieved. In addition, since the coil wiring is stacked on the magnetic layer or the crack generating layer, the position of the coil wiring, that is, the position of the coil is stable.

[0055] According to the coil component and the method for manufacturing the same of the present invention, stress between the coil wiring and the magnetic layer can be relaxed and the position of the coil can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1It is a perspective view showing a first embodiment of the coil component according to the present invention.

[0057] Figure 2 yes Figure 1 X-X section view.

[0058] Figure 3 This is an exploded top view of the coil component.

[0059] Figure 4 yes Figure 2 An enlarged cross-sectional view of section A.

[0060] Figure 5A This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0061] Figure 5B This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0062] Figure 5C This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0063] Figure 5D This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0064] Figure 5E This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0065] Fig. 5F This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0066] Figure 6 It is a cross-sectional view showing a second embodiment of the coil component according to the present invention.

[0067] Figure 7 This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0068] Figure 8 It is a cross-sectional view showing a third embodiment of the coil component according to the present invention.

[0069] Fig. 9 This is a cross-sectional view for explaining an example of a method for manufacturing a coil component.

[0070] Explanation of symbols:

[0071] 1, 1A, 1B…coil component; 10…substrate; 11…magnetic layer; 20, 20A, 20B…coil; 21, 21a, 21b…coil wiring; 25…connecting portion; 31…first external electrode; 32…second external electrode; 40…crack generating layer; 40a…crack; 111~114…first to fourth unfired magnetic layers; 211…unfired coil wiring; 400…unfired crack generating layer. DETAILED DESCRIPTION

[0072] Hereinafter, a coil component and a method for manufacturing the same according to one embodiment of the present disclosure will be described in detail with reference to the illustrated embodiments. In addition, the drawings include partial schematic diagrams and may not reflect actual dimensions or ratios.

[0073] (First Embodiment)

[0074] Figure 1 It is a perspective view showing a first embodiment of the coil component. Figure 2 yes Figure 1 The XX cross-sectional view is an LT cross-sectional view passing through the center of the coil component in the W direction. Figure 3 It is an exploded top view of the coil component, showing a view along the T direction from the lower figure to the upper figure. In addition, the L direction is the length direction of the coil component 1, the W direction is the width direction of the coil component 1, and the T direction is the height direction of the coil component 1. The T direction is an embodiment of the "first direction" described in the claims. Hereinafter, the forward direction of the T direction is also referred to as the upper side, and the reverse direction of the T direction is also referred to as the lower side.

[0075] like Figure 1 , Figure 2 , Figure 3 As shown, the coil component 1 includes a substrate 10 , a coil 20 provided inside the substrate 10 , a first external electrode 31 and a second external electrode 32 provided on the surface of the substrate 10 and electrically connected to the coil 20 .

[0076] The coil component 1 is electrically connected to wiring of a circuit board (not shown) via first and second external electrodes 31 and 32. The coil component 1 is used as a noise removal filter and is suitable for electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, and automotive electronics.

[0077] The substrate 10 is formed in a substantially rectangular parallelepiped shape. The surface of the substrate 10 has a first end face 15, a second end face 16 located on the opposite side of the first end face 15, and four side faces 17 located between the first end face 15 and the second end face 16. The first end face 15 and the second end face 16 are opposite to each other in the L direction.

[0078] The substrate 10 includes a plurality of magnetic layers 11. The plurality of magnetic layers 11 are alternately stacked in the T direction. The magnetic layers 11 are made of a magnetic material such as a Ni-Cu-Zn ferrite material. The thickness of the magnetic layer 11 is, for example, 5 μm or more and 30 μm or less. In addition, the substrate 10 may also partially include a non-magnetic layer.

[0079] The first external electrode 31 covers the entire surface of the first end surface 15 of the substrate 10 and the end of the side surface 17 of the substrate 10 on the first end surface 15 side. The second external electrode 32 covers the entire surface of the second end surface 16 of the substrate 10 and the end of the side surface 17 of the substrate 10 on the second end surface 16 side. The first external electrode 31 is electrically connected to the first end of the coil 20, and the second external electrode 32 is electrically connected to the second end of the coil 20. In addition, the first external electrode 31 may be an L-shaped formed over the first end surface 15 and one side surface 17, and the second external electrode 32 may be an L-shaped formed over the second end surface 16 and one side surface 17.

[0080] The coil 20 is wound in a spiral shape in the T direction. The coil 20 is made of a conductive material such as Ag or Cu. The coil 20 includes a plurality of coil wirings 21 and a plurality of lead conductor layers 61 and 62 .

[0081] The double first lead conductor layer 61, the plurality of coil wires 21, and the double second lead conductor layer 62 are sequentially stacked in the T direction and sequentially electrically connected via the connection portion 25. The connection portion 25 is provided to penetrate the magnetic layer 11 in the stacking direction.

[0082] Specifically, the four layers of coil wiring 21 are connected in sequence in the T direction to form a spiral along the T direction. The coil wiring 21 extends along a plane perpendicular to the T direction. The coil wiring 21 is formed into a shape that is wound less than one turn. The first lead conductor layer 61 is exposed from the first end surface 15 of the substrate 10 and connected to the first external electrode 31, and the second lead conductor layer 62 is exposed from the second end surface 16 of the substrate 10 and connected to the second external electrode 32.

[0083] The coil wiring 21 is composed of a single-layer coil conductor layer. The thickness of the coil conductor layer is, for example, greater than 10 μm and less than 40 μm. The coil conductor layer is formed, for example, by printing a conductor paste and drying it. In addition, the coil wiring 21 may also be composed of multiple layers of coil conductor layers. In this case, the multiple layers of coil conductor layers are stacked in the T direction, and the adjacent coil conductor layers in the T direction are in surface contact with each other.

[0084] Figure 4 yes Figure 2 That is, Figure 4 denoted a cross section perpendicular to the extension direction of the coil wiring 21. Figure 4As shown, the base body 10 further includes a crack inducing layer 40 which overlaps at least a part of the coil wiring 21 when viewed from the T direction. Cracks 40a exist inside the crack inducing layer 40.

[0085] The crack generation layer 40 is a layer that is more likely to generate cracks 40a than the magnetic layer 11. Specifically, the crack generation layer 40 is a layer with low toughness and is a layer that is likely to cause brittle fracture. For example, the crack generation layer 40 is lower in strength than the magnetic layer 11. The crack generation layer 40 is made of glass, for example. Preferably, the crack generation layer 40 has magnetism.

[0086] The crack 40a inside the crack generating layer 40 is contained inside the crack generating layer 40 and does not continuously extend into the inside of the magnetic layer 11. The crack 40a is smaller than a conventional void portion and is a so-called crack.

[0087] Thus, cracks 40a exist inside the crack generating layer 40, and thus the stress generated between the coil wiring 21 and the magnetic layer 11 can be relieved by the cracks 40a. In addition, since the coil wiring 21 is stacked on the magnetic layer 11 or the crack generating layer 40, the coil wiring 21 is not surrounded by a gap as in the past, and the position of the coil wiring 21, that is, the position of the coil 20, is stable.

[0088] In addition, the crack 40a has almost no thickness compared to the conventional gap, so that good characteristics (high inductance value or high impedance value) as the coil component 1 can be obtained. In addition, the crack 40a is contained in the crack generating layer 40, so the crack 40a does not reach the outside of the substrate 10, and the aging resistance is excellent. In addition, the crack 40a is provided in the crack generating layer 40, so the position where the crack 40a is generated and the size of the crack 40a can be controlled, and the shape of the crack 40a is also stable, and as a result, the difference in the characteristics of the coil component 1 can be reduced.

[0089] Furthermore, the stress can be further relaxed if the crack generating layer 40 overlaps the entire coil wiring 21 when viewed from the T direction. However, the crack generating layer 40 only needs to overlap at least a portion of the coil wiring 21 when viewed from the T direction.

[0090] In the coil component 1 of the present disclosure, cracks different from the above cracks 40 a may be provided in the magnetic layer 11 for purposes other than stress relaxation of the present application. In other words, the cracks 40 a provided for stress relaxation exist inside the crack generating layer 40 .

[0091] The crack generating layer 40 is preferably present between the magnetic layer 11 and the coil wiring 21 adjacent in the T direction. Thus, strong stress is generated at the boundary between the magnetic layer 11 and the coil wiring 21 adjacent in the T direction, but the stress can be effectively relaxed by providing the crack generating layer 40 at the boundary.

[0092] It is preferable to provide a plurality of crack initiation layers 40, and the plurality of crack initiation layers 40 are provided so as to be in contact with all the coil wirings 21. It is preferable that cracks 40a exist inside all the crack initiation layers 40. Thereby, stress can be further relaxed.

[0093] Furthermore, at least one crack generating layer 40 may be provided in contact with at least one coil wiring 21 among all the coil wirings 21. Furthermore, it is sufficient that the crack 40a is generated inside at least one crack generating layer 40 among all the crack generating layers 40. That is, there may be a crack generating layer 40 without the crack 40a among the plurality of crack generating layers 40.

[0094] It is preferable that the crack generating layer 40 also exists between the magnetic layer 11 and the coil wiring 21 which are adjacent to each other in the direction perpendicular to the T direction. Thereby, the stress in the direction perpendicular to the T direction can be relaxed.

[0095] Specifically, the coil wiring 21 has two surfaces 21a and 21b on both sides of the T direction in the cross section orthogonal to the extension direction of the coil wiring 21, and two side surfaces 21c and 21d on both sides of the direction orthogonal to the T direction (width direction). That is, the coil wiring 21 has an upper surface 21a on the upper side of the T direction, a lower surface 21b on the lower side of the T direction, an inner side surface 21c on the inner magnetic circuit side of the coil 20 in the width direction (the central axis side of the coil 20), and an outer side surface 21d on the outer magnetic circuit side of the coil 20 in the width direction (the side gap side of the substrate 10). The upper surface 21a is shorter than the lower surface 21b, and the cross-sectional shape of the coil wiring 21 is a trapezoid. In the cross section of the coil wiring 21, the thickness t of the coil wiring 21 in the T direction is smaller than the maximum width w of the coil wiring 21 in the L direction.

[0096] Furthermore, the crack generating layer 40 exists between the magnetic layer 11 and the upper surface 21a of the coil wiring 21, and also exists between the magnetic layer 11 and the inner side surface 21c and the outer side surface 21d of the coil wiring 21. Thus, the stress generated between the magnetic layer 11 and the upper surface 21a of the coil wiring 21 can be relieved, and the stress generated between the magnetic layer 11 and the inner side surface 21c and the outer side surface 21d of the coil wiring 21 can also be relieved.

[0097] In addition, the cross-sectional shape of the coil wiring 21 may not be a rectangle, but may be a polygon other than a quadrilateral, or may be an oblong or elliptical shape. Even in this case, the crack generating layer 40 exists between the magnetic layer 11 and the coil wiring 21 adjacent to each other in the T direction, and also exists between the magnetic layer 11 and the coil wiring 21 adjacent to each other in the direction orthogonal to the T direction.

[0098] In addition, the crack generating layer 40 may be provided in a manner of contacting the lower surface 21b, the inner side surface 21c, and the outer side surface 21d, or may be provided in a manner of contacting only the upper surface 21a or the lower surface 21b. That is, the crack generating layer 40 contacts the upper surface 21a or the lower surface 21b. Therefore, the crack generating layer 40 has a larger area than the inner side surface 21c and the outer side surface 21d, and is prone to generate stress. Since it contacts the upper surface 21a or the lower surface 21b, it can effectively relieve the stress.

[0099] The crack generating layer 40 preferably has an average thickness of 10 μm or less. Thus, the crack generating layer 40 is thin, and therefore, when the crack generating layer 40 has no magnetism, good characteristics (high inductance or high impedance) can be obtained as the coil component 1 .

[0100] Here, the average thickness of the crack generating layer 40 refers to the average thickness of the crack generating layer 40 in the cross section perpendicular to the extension direction of the coil wiring 21. For example, in the LT cross section passing through the center of the coil component 1 in the W direction and perpendicular to the extension direction of the coil wiring 21, the thickness of the crack generating layer 40 at multiple locations is measured and the average value is calculated.

[0101] It is preferred that the crack generating layer 40 contains glass with low toughness. Thus, cracks can be reliably generated in the crack generating layer 40. Here, low toughness means that "low toughness means that the viscosity of the material is low" and "it is easy to overcome external forces and break. That is, the crack progresses quickly, the ultimate strength is low, and the plasticity and ductility are low."

[0102] The magnetic permeability of the crack generating layer 40 is preferably greater than 1. Thus, good characteristics (high inductance or high impedance) can be obtained as the coil component 1. The magnetic permeability of the crack generating layer 40 is preferably less than or equal to the magnetic permeability of the magnetic layer. Thus, the desired characteristics can be obtained as the coil component 1.

[0103] Next, use Figure 5A to Figure 5F A method for manufacturing the coil component 1 will be described. Figure 5A to Figure 5F The LT cross section perpendicular to the extending direction of the coil wiring 21 is shown.

[0104] First, an unfired magnetic layer, an unfired crack-generating layer, and an unfired coil wiring are prepared. This is referred to as a preparation step. The unfired magnetic layer is made of magnetic slurry. The unfired coil wiring is made of conductive slurry. The unfired crack-generating layer is made of conductive slurry containing glass. In addition, the unfired crack-generating layer may be made of glass without containing conductive slurry, but by containing conductive slurry, it can be formed uniformly and thinly.

[0105] Next, the unfired magnetic layer, the unfired crack inducing layer, and the unfired coil wiring are stacked in the T direction so that the unfired crack inducing layer overlaps at least a portion of the unfired coil wiring when viewed from the T direction. This is referred to as a stacking step.

[0106] Specifically, if Figure 5A As shown, the green coil wiring 211 is stacked on the first green magnetic layer 111. The lower surface 211b of the green coil wiring 211 is in contact with the first green magnetic layer 111.

[0107] like Figure 5B As shown, the unfired crack inducing layer 400 is provided on the upper surface 211 a , the inner side surface 211 c , and the outer side surface 211 d of the unfired coil wiring 211 .

[0108] like Figure 5C As shown, a second unfired magnetic layer 112 is stacked on the first unfired magnetic layer 111 in such a manner that a portion of the unfired crack generating layer 400 that is opposite to the upper surface 211a of the unfired coil wiring 211 is exposed and a portion of the unfired crack generating layer 400 that is opposite to the inner side surface 211c and the outer side surface 211d of the unfired coil wiring 211 is covered.

[0109] like Figure 5D As shown, the third unfired magnetic layer 113 is stacked on the second unfired magnetic layer 112 so as to cover the portion of the unfired crack generating layer 400 facing the upper surface 211a of the unfired coil wiring 211. The stacking step is repeated a plurality of times to form a stacked body.

[0110] Next, the unfired magnetic layers 111 to 113, the unfired crack generation layer 400, and the unfired coil wiring 211 are fired, that is, the laminate is fired. Figure 5E As shown, the base 10 having the magnetic layer 11 and the crack generating layer 40 is obtained, and the coil 20 provided inside the base 10 and having the coil wiring 21 is obtained. The crack generating layer 40 overlaps at least a part of the coil wiring 21 when viewed from the T direction. This is called a firing step.

[0111] In the firing step, the unfired magnetic layers 111 to 113 are fired to form the magnetic layer 11. In addition, the conductive paste of a portion of the unfired crack generation layer 400 is fired together with the unfired coil wiring 211 to form the coil wiring 21. In addition, the glass of a portion of the unfired crack generation layer 400 is fired to form the crack generation layer 40.

[0112] Then, if Fig. 5F As shown in FIG. 1 , cracks 40a are generated inside the crack generating layer 40. This is referred to as a crack generating step. Figure 2 The coil component 1 is shown.

[0113] Thus, cracks 40a are generated inside crack generating layer 40, so that stress generated between coil wiring 21 and magnetic layer 11 can be relieved. In addition, since coil wiring 21 is stacked on magnetic layer 11 or crack generating layer 40, the position of coil wiring 21, that is, the position of coil 20 is stabilized.

[0114] The crack generating step is preferably a step of performing a thermal shock treatment with a temperature difference of 120° C. or more on the substrate 10. Thus, the cracks 40a can be reliably generated inside the crack generating layer 40. The thermal shock treatment is preferably a treatment of immersing the substrate 10 in liquid nitrogen one or more times. Thus, the cracks 40a can be generated inside the crack generating layer 40 by a simple method such as immersion.

[0115] Furthermore, the crack generating step may not be provided, and the crack 40a may be generated inside the crack generating layer 40 in the firing step. Specifically, the firing step further includes a step of performing a thermal shock treatment opened to the atmosphere (opening the furnace) at a firing temperature of 300° C. to generate the crack 40a inside the crack generating layer 40. Thus, compared with the case where the crack generating step is provided, additional equipment and steps for forming the crack 40a can be omitted.

[0116] (Second Embodiment)

[0117] Figure 6 1 is a cross-sectional view showing a second embodiment of the coil component of the present invention. The second embodiment is different from the first embodiment in the shape of the coil wiring. The different structure is described below. The other structures are the same as those of the first embodiment, so their description is omitted.

[0118] like Figure 6 As shown, in the coil component 1A of the second embodiment, the shape of the coil wiring 21A of the coil 20A is formed into an elliptical shape in a cross section perpendicular to the extending direction of the coil wiring 21A. The coil wiring 21A has an arc-shaped upper surface 21a and an arc-shaped lower surface 21b.

[0119] The coil wiring 21A is sandwiched between the two layers of magnetic layers 11. Specifically, the lower surface 21b of the coil wiring 21A is in contact with the lower magnetic layer 11. The crack generating layer 40 is present between the upper surface 21a of the coil wiring 21A and the upper magnetic layer 11. That is, the crack generating layer 40 is in contact with the upper surface 21a of the coil wiring 21A.

[0120] Furthermore, the crack generation layer 40 exists between the magnetic layer 11 and the coil wiring 21A adjacent to each other in the T direction. The crack generation layer 40 also exists between the magnetic layer 11 and the coil wiring 21A adjacent to each other in the L direction orthogonal to the T direction.

[0121] Next, a method for manufacturing the coil component 1A will be described.

[0122] like Figure 7 As shown, the first unfired magnetic layer 111, the unfired coil wiring 211, the unfired crack generating layer 400, and the second unfired magnetic layer 112 are stacked in order along the T direction. At this time, the lower surface 211b of the unfired coil wiring 211 is in contact with the first unfired magnetic layer 111, and the upper surface 211a of the unfired coil wiring 211 is in contact with the unfired crack generating layer 400. Different from the first embodiment described above, the unfired magnetic layer is composed of a magnetic sheet.

[0123] After that, through the firing step and the cracking step of the first embodiment, as Figure 6 As shown, cracks 40a are generated inside the crack generating layer 40 to manufacture the coil component 1A.

[0124] The coil component 1A according to the second embodiment has the same effects as those of the coil component 1 according to the first embodiment described above.

[0125] (Third Embodiment)

[0126] Figure 8 1 is a cross-sectional view showing a third embodiment of the coil component of the present invention. The third embodiment is different from the first embodiment in the shape of the coil wiring and the position of the crack generating layer. The different structures are described below. The other structures are the same as those of the first embodiment, so their description is omitted.

[0127] like Figure 8 As shown, in the coil component 1B of the third embodiment, the shape of the coil wiring 21B of the coil 20B is formed into an ellipse in a cross section perpendicular to the extending direction of the coil wiring 21B. The coil wiring 21B has an arc-shaped upper surface 21a and an arc-shaped lower surface 21b.

[0128] The coil wiring 21B is sandwiched between the two magnetic layers 11. Specifically, the lower surface 21b of the coil wiring 21B is in contact with the lower magnetic layer 11. The upper surface 21a of the coil wiring 21B is in contact with the upper magnetic layer 11.

[0129] The crack generating layer 40 exists between two coil wirings 21B adjacent to each other in the T direction. Thus, the stress generated between the two coil wirings 21B adjacent to each other in the T direction can be effectively alleviated.

[0130] Specifically, the crack generating layer 40 exists between two magnetic layers 11 adjacent to each other in the T direction. That is, the crack generating layer 40 is not in contact with the coil wiring 21B. Thus, the crack generating layer 40 can be easily provided compared to the case where the crack generating layer 40 is provided directly on the coil wiring 21B.

[0131] In the cross section perpendicular to the extension direction of the coil wiring 21B, the width of the crack generating layer 40 is the same as the width of the coil wiring 21B in terms of the width in the L direction perpendicular to the T direction. In addition, the width of the crack generating layer 40 may be larger than the width of the coil wiring 21B, in which case the stress can be further relieved by the cracks 40a inside the crack generating layer 40. On the other hand, the width of the crack generating layer 40 may be smaller than the width of the coil wiring 21B, in which case the crack generating layer 40 does not extend to the outer magnetic circuit or the inner magnetic circuit of the base 10, and the crack generating layer 40 does not hinder the magnetic flux of the coil 20B.

[0132] Next, a method for manufacturing the coil component 1B will be described.

[0133] like Fig. 9 As shown, the first unfired magnetic layer 111, the first unfired coil wiring 211, the second unfired magnetic layer 112, the unfired crack generation layer 400, the third unfired magnetic layer 113, the second unfired coil wiring 211, and the fourth unfired magnetic layer 114 are stacked in order along the T direction. At this time, the lower surface 211b of the first unfired coil wiring 211 is in contact with the first unfired magnetic layer 111, and the upper surface 211a of the first unfired coil wiring 211 is in contact with the second unfired magnetic layer 112. In addition, the lower surface 211b of the second unfired coil wiring 211 is in contact with the third unfired magnetic layer 113, and the upper surface 211a of the second unfired coil wiring 211 is in contact with the fourth unfired magnetic layer 114. In addition, the unfired crack generation layer 400 exists in a portion between the second unfired magnetic layer 112 and the third unfired magnetic layer 113. Different from the above-mentioned first embodiment, the unfired magnetic layer is composed of a magnetic sheet.

[0134] After that, through the firing step and the cracking step of the first embodiment, as Figure 8As shown, cracks 40a are generated inside the crack generating layer 40 to manufacture the coil component 1B.

[0135] The coil component 1B according to the third embodiment has the same effects as those of the coil component 1 according to the first embodiment described above.

[0136] In addition, the present invention is not limited to the above-mentioned embodiments, and design changes can be made within the scope of the present invention. For example, various combinations of the characteristic points of the first to third embodiments can be made. The number of coil wirings and the number of crack generation layers can be increased or decreased.

Claims

1. A coil component, wherein: have: matrix, and A coil is disposed in the base body. The substrate has a plurality of magnetic layers stacked in a first direction, The coil has a plurality of coil wirings stacked in the first direction, The base further includes a crack inducing layer overlapping at least a portion of the coil wiring when viewed from the first direction, There are cracks inside the crack generating layer. The crack generating layer includes low-toughness glass having lower toughness than that of the magnetic layer, The crack-inducing layer is made of glass.

2. The coil component according to claim 1, wherein The crack generating layer exists between the magnetic layer and the coil wiring which are adjacent to each other in the first direction.

3. The coil component according to claim 1, wherein The crack generating layer exists between two of the coil wirings adjacent to each other in the first direction.

4. The coil component according to claim 3, wherein: The crack generating layer exists between two of the magnetic layers adjacent to each other in the first direction.

5. The coil component according to any one of claims 1 to 4, wherein: The crack generating layer also exists between the magnetic layer and the coil wiring which are adjacent to each other in a direction orthogonal to the first direction.

6. The coil component according to claim 5, wherein The coil wiring extends along a plane orthogonal to the first direction, The coil wiring has two side surfaces on both sides of a direction perpendicular to the first direction in a cross section perpendicular to the extending direction of the coil wiring. The crack generating layer exists between the magnetic layer and the side surface of the coil wiring.

7. The coil component according to any one of claims 1 to 4, wherein: The crack-inducing layer has an average thickness of 10 μm or less.

8. The coil component according to any one of claims 1 to 4, wherein: The magnetic permeability of the crack inducing layer is greater than 1.

9. The coil component according to claim 8, wherein The magnetic permeability of the crack generating layer is less than or equal to the magnetic permeability of the magnetic layer.

10. A method for manufacturing a coil component, wherein: have: A preparation step of preparing an unfired magnetic layer, an unfired crack generating layer, and an unfired coil wiring; a lamination step of laminating the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring in a first direction so that the unfired crack generating layer overlaps at least a portion of the unfired coil wiring when viewed from the first direction; A firing step of firing the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring to obtain a substrate having the magnetic layer and the crack generating layer overlapping at least a portion of the coil wiring when viewed from the first direction, and to obtain a coil disposed inside the substrate and having the coil wiring; as well as a crack generating step of generating cracks in the crack generating layer; The crack generating layer includes low-toughness glass having lower toughness than that of the magnetic layer, The crack-inducing layer is made of glass.

11. The method for manufacturing a coil component according to claim 10, wherein: The crack generating step is a step of subjecting the substrate to a thermal shock treatment with a temperature difference of 120° C. or more at least once.

12. The method for manufacturing a coil component according to claim 11, wherein: The thermal shock treatment is a treatment in which the substrate is immersed in liquid nitrogen one or more times.

13. A method for manufacturing a coil component, wherein: have: A preparation step of preparing an unfired magnetic layer, an unfired crack generating layer, and an unfired coil wiring; a lamination step of laminating the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring in a first direction so that the unfired crack generating layer overlaps at least a portion of the unfired coil wiring when viewed from the first direction; as well as a firing step of firing the unfired magnetic layer, the unfired crack generating layer, and the unfired coil wiring to obtain a substrate having the magnetic layer and the crack generating layer overlapping at least a portion of the coil wiring when viewed from the first direction, and a coil provided inside the substrate and having the coil wiring, The firing step further includes a step of performing a thermal shock treatment open to the atmosphere at a firing temperature of 300° C. to generate cracks inside the crack generating layer. The crack generating layer includes low-toughness glass having lower toughness than that of the magnetic layer, The crack-inducing layer is made of glass.

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