Ceramic composition and wire-wound coil component

Abstract

The present invention provides a ceramic composition capable of suppressing chipping during barrel polishing, cracks during heat press bonding, plating extension, and high specific resistance. The ceramic composition of the present invention contains Fe, Cu, Zn, Ni, Mn, Nb, and V, and when Fe, Cu, Zn, and Ni are converted into Fe2O3, CuO, ZnO, and NiO, respectively, and the total amount of Fe2O3, CuO, ZnO, and NiO is set to 100 mol%, Fe converted into Fe2O3 is contained in an amount of 46.70 mol% to 49.70 mol%, Cu converted into CuO is contained in an amount of 4.00 mol% to 7.50 mol%, Zn converted into ZnO is contained in an amount of 7.00 mol% to 33.50 mol%, and the remaining portion is Ni, Mn converted into Mn2O3 is contained in an amount of 300 ppm to 10,000 ppm, Nb converted into Nb2O5 is contained in an amount of 2 ppm to 30 ppm, and V converted into V2O5 is contained in an amount of 10 ppm to 60 ppm, with respect to 100 parts by weight of the total amount of Fe2O3, CuO, ZnO, and NiO.

Description

Technical Field

[0001] This invention relates to ceramic compositions and wound coil components. Background Technology

[0002] Patent Document 1 discloses a winding-type coil device using a drum-shaped iron core having a core portion and a flange portion. According to the coil device described in Patent Document 1, the first mounting protrusion of the flange portion formed at one end of the core portion and the second mounting protrusion of the flange portion formed at the other end of the core portion are arranged in a positionally offset manner, thus exhibiting excellent thermal shock resistance.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-125397 Summary of the Invention

[0006] Patent document 1 describes that drum-shaped iron cores can be manufactured, for example, by forming and sintering ferrite materials such as Ni-Zn ferrite or Mn-Zn ferrite.

[0007] However, there are concerns that cores made of ferrite materials may crack during tumble polishing or that the wires may crack during hot-pressing of the terminal electrodes. Furthermore, when the terminal electrodes on the bottom surface of the core are formed by plating, there is a concern about a defect called "plating elongation," which occurs when the plating deviates from its target position.

[0008] The present invention was made to solve the above-mentioned problems, and its object is to provide a ceramic composition that can suppress breakage during tumble polishing, cracking during hot pressing, and plating extension, and has a high resistivity. Furthermore, the object of the present invention is to provide a wound coil component having the above-mentioned ceramic composition as a ceramic core.

[0009] The ceramic composition of the present invention is a ceramic composition containing Fe, Cu, Zn, Ni, Mn, Nb and V. When Fe, Cu, Zn and Ni are converted to Fe2O3, CuO, ZnO and NiO respectively, and the total amount of Fe2O3, CuO, ZnO and NiO is set to 100 mol%, Fe is 46.70 mol% to 49.70 mol% when converted to Fe2O3, Cu is 4.00 mol% to 7.50 mol% when converted to CuO, Zn is 7.00 mol% to 33.50 mol% when converted to ZnO, and the remainder is Ni. Relative to the total amount of Fe2O3, CuO, ZnO and NiO (100 parts by weight), Mn is 300 ppm to 10000 ppm when converted to Mn2O3, Nb is 2 ppm to 30 ppm when converted to Nb2O5, and V is 10 ppm to 60 ppm when converted to V2O5.

[0010] The wound coil component of the present invention includes a ceramic core, terminal electrodes, and conductive wires; the ceramic core includes: a core portion extending in the length direction and a pair of flange portions disposed at two opposing ends of the core portion in the length direction, each flange portion having an inner end face facing the core portion in the length direction, an outer end face opposite to the inner end face in the length direction, a pair of opposing side faces in the width direction, and a top surface and a bottom surface opposing each other in the height direction; the terminal electrodes are disposed at least on the bottom surface of the flange portions of the ceramic core; the conductive wires are wound around the core portion of the ceramic core, and their ends are electrically connected to the terminal electrodes; the ceramic core is composed of the ceramic composition of the present invention.

[0011] According to the present invention, a ceramic composition can be provided that can suppress breakage during tumble polishing, cracking during hot pressing, and plating extension, and has a high resistivity. Furthermore, according to the present invention, a wound coil component comprising the above-described ceramic composition as a ceramic core can be provided. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating an example of the surface of the ceramic composition of the present invention.

[0013] Figure 2 This is a schematic diagram illustrating an example of a polished surface of the ceramic composition of the present invention.

[0014] Figure 3 A front view schematically illustrating an example of a wound coil component of the present invention.

[0015] Figure 4 schematic representation of composition Figure 3 A perspective view of an example of a ceramic core for a wound coil component.

[0016] Symbol Explanation

[0017] 1. Ceramic composition

[0018] 2. Grains

[0019] 3. Grain boundary layer

[0020] 10. Wire-wound coil components

[0021] 20 Ceramic Core

[0022] 30 core sections

[0023] 31, 32 Main surfaces of the core

[0024] 33, 34 Sides of the core

[0025] 40 Flange portion

[0026] 41. Inner end face of the flange portion

[0027] 42. Outer end face of the flange portion

[0028] 43, 44 Side surfaces of the flange

[0029] 45 Top surface of the flange

[0030] 46 Bottom surface of the flange

[0031] 50 terminal electrodes

[0032] 55 wire

[0033] L (length direction)

[0034] T in the height direction

[0035] W width direction Detailed Implementation

[0036] The ceramic composition and the wound coil component of the present invention will be described below.

[0037] However, the present invention is not limited to the following configurations, and appropriate modifications and uses are permitted without altering the spirit of the invention. It should be noted that combinations of two or more preferred configurations of the present invention described below also fall under the scope of the present invention.

[0038] [Ceramic Composition]

[0039] The ceramic composition of the present invention contains Fe, Cu, Zn, Ni, Mn, Nb, and V. The ceramic composition of the present invention, for example, contains ferrite as a main component, preferably spinel-type ferrite as a main component.

[0040] In this specification, ceramic composition refers to a sintered body, preferably a core-shaped sintered body. Therefore, in the ceramic composition of the present invention, the aforementioned atoms are mixed at the atomic level. That is, the ceramic composition of the present invention is synonymous with ferrite sintered body.

[0041] In the ceramic composition of the present invention, when Fe, Cu, Zn and Ni are converted to Fe2O3, CuO, ZnO and NiO respectively, and the total amount of Fe2O3, CuO, ZnO and NiO is set to 100 mol%, the Fe2O3 composition contains 46.70 mol% to 49.70 mol% Fe, the CuO composition contains 4.00 mol% to 7.50 mol% Cu, the ZnO composition contains 7.00 mol% to 33.50 mol% Zn, and the remainder contains Ni.

[0042] In the ceramic composition of the present invention, 100 parts by weight of Fe2O3, CuO, ZnO and NiO, when converted to Mn2O3, contain 300ppm to 10000ppm of Mn, when converted to Nb2O5, contain 2ppm to 30ppm of Nb, and when converted to V2O5, contain 10ppm to 60ppm of V.

[0043] In the ceramic composition of the present invention, by ensuring that the contents of Fe, Cu, Zn, Ni, Mn, Nb, and V are within the aforementioned ranges, it is possible to suppress breakage during tumble polishing, cracking during hot pressing, and plating extension, and to improve resistivity. For example, the ceramic composition described in the examples below can be obtained, wherein the core breakage rate during tumble polishing is less than 0.15%, the crack occurrence rate during hot pressing is less than 0.20%, the plating extension is less than 70 μm, and the resistivity (logρ) is 1.0 × 10⁻⁶. 8 Ωm or above.

[0044] The ceramic composition of the present invention may further contain Co. In this case, the ceramic composition of the present invention preferably contains 500 ppm to 6000 ppm Co, relative to 100 parts by weight of the combined amount of Fe2O3, CuO, ZnO and NiO, converted to CoO. If the ceramic composition of the present invention contains Co within the above range, the plating extension can be further suppressed.

[0045] The content of each element can be determined by analyzing the composition of the ceramic composition using inductively coupled plasma optical emission / mass spectrometry (ICP-AES / MS).

[0046] The ceramic composition of the present invention may further contain other elements. Additionally, the ceramic composition of the present invention may further contain unavoidable impurities.

[0047] In the ceramic composition of the present invention, the average grain diameter in the sintered state is preferably 2.2 μm to 9.0 μm. If the average grain diameter is within the above range, breakage during tumble polishing can be further suppressed.

[0048] Figure 1 This is a schematic diagram illustrating an example of the surface of the ceramic composition of the present invention.

[0049] Figure 1 The ceramic composition 1 shown comprises multiple grains 2 and grain boundary layers 3 between the grains 2. In the grain boundary layer 3, Cu is precipitated in large quantities, and the coating can be considered to extend along the grain boundary layer 3.

[0050] Figure 2 This is a schematic diagram illustrating an example of a polished surface of the ceramic composition of the present invention.

[0051] As illustrated in the examples described later, the average grain diameter of the ceramic composition can be used as a measure of the average grain diameter of the ceramic composition. Figure 2 The average grain diameter was calculated from the polished surface of the ceramic composition 1 as shown.

[0052] It should be noted that the grain diameter of the ceramic composition can be adjusted by factors such as calcination temperature and composition. For example, increasing the calcination temperature can increase the grain diameter. Additionally, increasing the Cu content in the ceramic composition can also increase the grain diameter.

[0053] The ceramic composition of the present invention is preferably manufactured as follows.

[0054] First, Fe2O3, CuO, ZnO, NiO, Mn2O3, Nb2O5, V2O5, and CoO (if desired) are weighed to achieve the specified composition after calcination. This mixture is then placed in a ball mill along with pure water and PSZ (partially stabilized zirconia) balls and wet-mixed and pulverized for a specified time (e.g., 4 to 8 hours). After evaporation and drying, it is pre-calcined at a specified temperature (e.g., 700°C to 800°C) for a specified time (e.g., 2 to 5 hours) to produce a pre-calcined product (pre-calcined powder).

[0055] The obtained pre-calcined material (pre-calcined powder) was placed in a ball mill along with pure water, polyvinyl alcohol as a binder, dispersant, plasticizer, and PSZ balls for wet mixing and pulverization. The pulverized mixture was then dried and granulated in a spray dryer to produce granular powder.

[0056] Prepare a mold, press the prepared granular powder into shape, and form a molded body.

[0057] Next, the molded body is calcined in a calcining furnace at a specified temperature (e.g., 1000°C to 1200°C) for a specified time (e.g., 2 hours to 5 hours). Through the above process, a ceramic composition is obtained.

[0058] The ceramic composition of the present invention can be used, for example, in the ceramic core of a wound coil component. It should be noted that the use of the ceramic composition of the present invention is not particularly limited; for example, it can be used in the unit cell of a multilayer inductor, etc.

[0059] [Wire-wound coil component]

[0060] The wound coil component of the present invention comprises the ceramic composition of the present invention as a ceramic core.

[0061] Figure 3 A front view schematically illustrating an example of a wound coil component of the present invention. Figure 4 schematic representation of composition Figure 3 A perspective view of an example of a ceramic core for a wound coil component.

[0062] Figure 3 and Figure 4 For illustrative purposes only, the dimensions, aspect ratio, and scale may sometimes differ from the actual product.

[0063] In the following description, terms indicating the relationship between elements (such as "perpendicular", "parallel", "orthogonal") and terms indicating the shape of elements do not only indicate the situation in a strict sense, but also include substantially equivalent ranges, such as including differences of several percent.

[0064] Figure 3 The wound coil component 10 shown includes a ceramic core 20, terminal electrodes 50, and wires (coils) 55. The ceramic core 20 is made of the ceramic composition of the present invention.

[0065] like Figure 3 and Figure 4 As shown, the ceramic core 20 includes a core portion 30 extending in the length direction L, and a pair of flange portions 40 disposed at opposite ends of the core portion 30 in the length direction L. The core portion 30 and the flange portions 40 are integrally formed.

[0066] In this instruction manual, such as Figure 3 and Figure 4 As shown, the direction in which the pair of flanges 40 are arranged side by side is defined as the length direction L, and the direction orthogonal to the length direction L is defined as... Figure 3 and Figure 4 The vertical direction is defined as the height direction (thickness direction) T, and the direction that is orthogonal to both the length direction L and the height direction T is defined as the width direction W.

[0067] The core portion 30 is formed, for example, as a cuboid extending in the length direction L. The central axis of the core portion 30 extends parallel to the length direction L. The core portion 30 has: a pair of main surfaces 31 and 32 facing each other in the height direction T, and a pair of side surfaces 33 and 34 facing each other in the width direction W.

[0068] In this specification, the term "cubic parallelogram" also includes cuboids with chamfered corners and edges, and cuboids with rounded corners and edges. Furthermore, some or all of the main face and side faces may be formed with concave or convex shapes.

[0069] A pair of flange portions 40 are provided at both ends of the core portion 30 in the length direction L. Each flange portion 40 is formed into a thin cuboid shape in the length direction L. Each flange portion 40 is formed to protrude toward the periphery of the core portion 30 toward the height direction T and the width direction W. Specifically, when viewed from the length direction L, the planar shape of each flange portion 40 is formed to protrude relative to the core portion 30 in the height direction T and the width direction W.

[0070] Each flange portion 40 has: an inner end face 41 facing the core portion 30 in the length direction L, an outer end face 42 opposite to the inner end face 41 in the length direction L, a pair of side faces 43 and 44 facing each other in the width direction W, and a top surface 45 and a bottom surface 46 facing each other in the height direction T. The inner end face 41 of one flange portion 40 is arranged opposite to the inner end face 41 of another flange portion 40.

[0071] The inner end face 41 of each flange portion 40 is formed, for example, so that all its surfaces extend perpendicularly to the direction in which the core portion 30 extends (here, the length direction L). That is, all its surfaces of the inner end face 41 of each flange portion 40 are formed to extend parallel to the height direction T. However, the inner end face 41 of each flange portion 40 may also be formed as an inclined surface.

[0072] like Figure 3 As shown, terminal electrodes 50 are provided at least on the bottom surface 46 of each flange portion 40. For example, when the wound coil component 10 is mounted on the circuit board, the terminal electrodes 50 can be electrically connected to the electrodes of the circuit board. The terminal electrodes 50 are made, for example, of Ni-based alloys such as nickel (Ni)-chromium (Cr) and Ni-copper (Cu), silver (Ag), Cu, tin (Sn), etc.

[0073] The conductor 55 is wound around the core portion 30. The conductor 55 has, for example, a core wire mainly composed of a conductive material such as Cu, which is coated with an insulating material such as polyurethane or polyester. The two ends of the conductor 55 are electrically connected to the terminal electrodes 50, respectively.

[0074] Although Figure 3Not shown, but multiple terminal electrodes 50 may be provided on the bottom surface 46 of each flange portion 40. In addition, multiple wires 55 may be wound on the core portion 30.

[0075] The wound coil component of the present invention can be manufactured, for example, as follows.

[0076] As described in the [Ceramic Composition] section above, granular powder is pressed and molded to form a molded body. Next, the molded body is calcined in a calcining furnace at a specified temperature (e.g., 1000°C to 1200°C) for a specified time (e.g., 2 hours to 5 hours). The resulting sintered body is then fed into a barrel and polished using a polishing material. This tumbler polishing removes burrs from the sintered body, giving the outer surface of the sintered body (especially the corners and edges) a rounded, curved shape. Through the above processes, a product is obtained... Figure 4 The ceramic core shown.

[0077] Next, terminal electrodes are formed on at least the bottom surface of the flange portion of the ceramic core. For example, a conductive paste containing Ag and glass frit is coated onto the bottom surface of the flange portion, and a base metal layer is formed by baking at a specified temperature (e.g., 800°C to 820°C). Then, a Ni plating film and a Sn plating film are sequentially formed on the base metal layer by electrolytic plating, thereby forming a plating layer. Alternatively, a metal terminal can be mounted on the bottom surface of the flange portion to serve as a terminal electrode.

[0078] Next, after winding the wire around the core of the ceramic core, the end of the wire is joined to the terminal electrode using known methods such as thermoforming. Through these processes, a product can be manufactured. Figure 3 A wound coil component as shown.

[0079] The wound coil component of the present invention is not limited to the embodiments described above, and various applications and modifications can be applied within the scope of the present invention. Other shapes may include, for example, a top plate extending in the longitudinal direction L and connecting the flange portions. Furthermore, the periphery of the conductor may be coated with resin. The shape of the core is not limited to a drum-shaped core, but may also be a ring-shaped core.

[0080] In the wound coil component of the present invention, the shape and size of the core portion of the ceramic core, the shape and size of the flange portion of the ceramic core, the thickness (wire diameter), number of turns, cross-sectional shape of the wire, and the number of wires are not particularly limited and can be appropriately changed according to the desired characteristics and installation location. Furthermore, the position and number of terminal electrodes can be appropriately set according to the number of wires and their intended use.

[0081] The following information is disclosed in this specification.

[0082] <1>

[0083] A ceramic composition comprising Fe, Cu, Zn, Ni, Mn, Nb and V;

[0084] When Fe, Cu, Zn, and Ni are converted to Fe2O3, CuO, ZnO, and NiO respectively, and the total amount of Fe2O3, CuO, ZnO, and NiO is set to 100 mol%, the Fe2O3 composition contains 46.70 mol% to 49.70 mol% Fe, the CuO composition contains 4.00 mol% to 7.50 mol% Cu, and the ZnO composition contains 7.00 mol% to 33.50 mol% Zn, with Ni as the remainder.

[0085] Relative to 100 parts by weight of the total amount of Fe2O3, CuO, ZnO and NiO, when converted to Mn2O3, it contains 300ppm to 10000ppm of Mn; when converted to Nb2O5, it contains 2ppm to 30ppm of Nb; and when converted to V2O5, it contains 10ppm to 60ppm of V.

[0086] <2>

[0087] According to the ceramic composition described in <1>, the average grain diameter in the sintered state is 2.2 μm to 9.0 μm.

[0088] <3>

[0089] According to the ceramic composition described in <1> or <2>, the composition contains 500 ppm to 6000 ppm Co relative to 100 parts by weight of Fe2O3, CuO, ZnO and NiO, which is converted to CoO.

[0090] <4>

[0091] A wound coil component includes a ceramic core, terminal electrodes, and wires; the ceramic core includes a core portion extending in the length direction and a pair of flange portions disposed at opposite ends of the core portion in the length direction, each flange portion having an inner end face facing the core portion in the length direction, an outer end face opposite to the inner end face in the length direction, a pair of side faces opposite in the width direction, and a top surface and a bottom surface opposite in the height direction;

[0092] The aforementioned terminal electrodes are disposed on at least the aforementioned bottom surface of the aforementioned flange portion of the aforementioned ceramic core;

[0093] The aforementioned wire is wound around the aforementioned core portion of the aforementioned ceramic core, and its end is electrically connected to the aforementioned terminal electrode;

[0094] The ceramic core described above is composed of the ceramic composition described in any one of <1> to <3>.

[0095] Example

[0096] The following examples illustrate ceramic compositions that further disclose the present invention. It should be noted that the present invention is not limited to these examples.

[0097] [Example 1]

[0098] Fe₂O₃, CuO, ZnO, NiO, Mn₂O₃, Nb₂O₅, and V₂O₅ were weighed to obtain the composition shown in Table 1. This mixture was then placed in a ball mill along with pure water and PSZ balls and wet-mixed and pulverized for 4 hours. After evaporation and drying, it was pre-calcined at 800°C for 2 hours to produce the pre-calcined material.

[0099] The pre-calcined material was mixed and pulverized together with pure water, polyvinyl alcohol as a binder, dispersant, plasticizer, and PSZ balls in a ball mill. The resulting slurry was then dried and granulated in a spray dryer to produce granular powder.

[0100] The prepared granular powder is pressed into a mold, and the dimensions of the molded product are as follows:

[0101] • An H-shaped iron core sample with a length L dimension of 3.9 mm, a width W dimension of 2.8 mm, and a height T dimension of 2.2 mm, or...

[0102] • A molded body of a ring-shaped sample with an outer diameter of 20 mm, an inner diameter of 12 mm, and a thickness of 1.5 mm.

[0103] The molded body was calcined at 1100℃ for 2 hours. Based on the above procedures, samples 1 to 25 were prepared.

[0104] For each sample, the composition of the sintered body was analyzed using ICP-AES / MS to determine the content of each element. The results are shown in Table 1. Table 1 shows the content converted to oxides of each element.

[0105] For the annular specimens 1–25, the surface resistivity was measured using a high-resistivity meter (Agilent Technologies, Inc., 4339A). The specific resistivity (logρ) was calculated from the surface resistivity and specimen size. For each specimen, the average value was calculated for n = 5 specimens. The results are shown in Table 1. A specific resistivity of 1.0 × 10⁻⁶ was used. 8 Conditions above Ωm are judged as ○ (good), and those less than 1.0 × 10 8 The condition of Ωm is judged as × (defective).

[0106] For samples 1–25, 20,000 core samples of each type were tumble-polished at 80 rpm for 60 minutes. 8,000 samples were selected, and a substrate appearance inspection device (Tokyo Weld Co., Ltd., TWA-4101) was used to confirm whether the core samples had fractured after tumble polishing, thus calculating the core fracture rate. Core fracture rates below 0.15% during tumble polishing were classified as ○ (good), and those exceeding 0.15% were classified as × (bad). The results are shown in Table 1.

[0107] Terminal electrodes were formed on the bottom surface of the iron core samples 1 to 25. Specifically, after forming a base metal layer by coating Ag paste onto the bottom surface of the iron core sample and baking it, a plating layer including a Cu layer, a Ni layer, and a Sn layer was formed by plating. The plating conditions were set such that the thicknesses of the Cu layer / Ni layer / Sn layer were 5 μm / 4 μm / 15 μm, respectively. The dimension extending from the target position of the plating layer was measured as the plating extension. For each sample, the average value was calculated with n = 10 samples. Cases with a plating extension of less than 70 μm were judged as ○ (good), and cases with an extension of more than 70 μm were judged as × (bad). The results are shown in Table 1.

[0108] For core samples 1 to 25, the wires and terminal electrodes were joined by thermoforming. Specifically, a heating chip heated to 450°C was used, and pressure was applied at 0.8 N. A substrate appearance inspection device (Tokyo Weld Co., Ltd., TWA-4101) was used to check for cracks in the thermoformed core samples, and the crack incidence rate was calculated. For each sample, an average value was calculated for n = 8000 samples. A crack incidence rate of less than 0.20% during thermoforming was classified as ○ (good), and a rate exceeding 0.20% was classified as × (bad). The results are shown in Table 1.

[0109]

[0110] In Table 1, the samples marked with * are comparative examples that are outside the scope of this invention.

[0111] According to Table 1, among samples 2–4, 7, 8, 11, 12, 15, 16, 19, 20, 23, and 24 containing Fe, Cu, Zn, Ni, Mn, Nb, and V within the specified range, the following results were obtained: core breakage rate during tumble polishing below 0.15%, crack incidence rate during hot pressing below 0.20%, plating elongation below 70 μm, and resistivity (logρ) of 1.0 × 10⁻⁶. 8 Ceramic compositions with an Ωm or higher.

[0112] [Example 2]

[0113] Samples 26–29, which had the same composition as sample 3 in Table 1 but with grain diameters varying by calcination temperature, were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0114] The average grain diameter in the sintered state is calculated based on the grain diameter obtained by the method shown below.

[0115] For the H-shaped iron core samples 3 and 26–29, polishing and surface planarization were performed using an automatic polishing device (Struers Tegramin-25), followed by observation of the polished surfaces using a scanning electron microscope (SEM). Based on the SEM images of the polished surfaces, the grain diameter was calculated using the image analysis software WinROOF. For each sample, the average grain diameter was taken as the average of the grain diameters with n = 50 or higher. The results are shown in Table 2.

[0116] Table 2

[0117]

[0118] According to Table 2, in samples 3, 27 and 28 with an average grain diameter of 2.2 μm to 9.0 μm in the sintered state, the core breakage rate during tumble polishing can be suppressed to below 0.10%.

[0119] [Example 3]

[0120] Samples 30-33, with the same composition as sample 3 in Table 1 but with different Co content, were evaluated in the same manner as in Example 1. The method for determining the Co content was the same as in Example 1. The results are shown in Table 3.

[0121] Table 3

[0122]

[0123] According to Table 3, in samples 3, 31, and 32, which contain 500 ppm to 6000 ppm Co (converted to CoO), the plating elongation can be suppressed to below 60 μm. This is believed to be because the amount of Cu extruded to the grain boundaries is reduced by Co, resulting in increased resistivity, thus suppressing plating elongation.

[0124] It should be noted that although not shown in Table 1 of Example 1 and Table 2 of Example 2, samples 1, 2 and 4 to 29 contain the same amount of Co as sample 3.

Claims

1. A ceramic composition comprising a ferrite as a main component, containing Fe, Cu, Zn, Ni, Mn, Nb, and V, further containing Co; wherein, when Fe, Cu, Zn, and Ni are converted into Fe2O3, CuO, ZnO, and NiO, respectively, and the total amount of Fe2O3, CuO, ZnO, and NiO is set to 100 mol%, Fe converted into Fe2O3 is contained in an amount of 46.70 mol% to 49.70 mol%, Cu converted into CuO is contained in an amount of 4.00 mol% to 7.50 mol%, Zn converted into ZnO is contained in an amount of 7.00 mol% to 33.50 mol%, and the remainder is Ni; and, further, relative to 100 parts by weight of the total amount of Fe2O3, CuO, ZnO, and NiO, Mn converted into Mn2O3 is contained in an amount of 300 ppm to 10,000 ppm, Nb converted into Nb2O5 is contained in an amount of 2 ppm to 30 ppm, and V converted into V2O5 is contained in an amount of 10 ppm to 60 ppm, Co converted into CoO is contained in an amount of 500 ppm to 6,000 ppm. The average grain diameter in a sintered state is 2.2 μm to 9.0 μm.

3. A wire-wound coil component comprising a ceramic core, a terminal electrode, and a wire; the ceramic core comprising a winding core portion extending in a length direction and a pair of flange portions provided to both end portions opposite in the length direction of the winding core portion, each of the flange portions having an inner side end surface toward the winding core portion side in the length direction, an outer side end surface opposite the inner side end surface in the length direction, a pair of side surfaces opposite in a width direction, and a top surface and a bottom surface opposite in a height direction; the terminal electrode being provided to at least the bottom surface of the flange portion of the ceramic core; the wire being wound around the winding core portion of the ceramic core with an end portion electrically connected to the terminal electrode; and the ceramic core being composed of the ceramic composition according to claim 1 or 2. ​ 2. The ceramic composition of claim 1, wherein, ​ ​ ​ ​ ​

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