Laminated coil components

Abstract

This invention provides a multilayer coil component that reduces current concentration around the connection portion of a conductor pattern and offers high reliability. The multilayer coil component comprises: a multilayer body formed by stacking insulating layers; a coil disposed within the multilayer body; and an external electrode disposed on the surface of the multilayer body and electrically connected to the coil. The multilayer coil component is characterized in that the coil includes at least two coil conductor groups, each coil conductor group comprising at least two coil conductors connected in parallel via two connecting conductors, and the at least two coil conductor groups are connected in series via connecting conductors, which connect the coil conductors between the two connecting conductors of each coil conductor group to each other.

Description

Technical Field

[0001] The present disclosure relates to a laminated coil component. Background Art

[0002] With the recent trend of high current, coil components are required to have low DC resistance. In order to reduce DC resistance, the cross-sectional area of ​​the conductor constituting the coil is usually increased. However, in stacked coil components, if the coil conductor becomes thicker, structural defects such as cracks may occur.

[0003] In response to the above-mentioned problem, Patent Document 1 discloses: "A laminated electronic component, which is laminated with an insulating layer and a conductor pattern, and the conductor pattern is connected between the insulating layers to form a coil in the laminate, the laminated electronic component is characterized in that the coil has a pair of conductor patterns, the pair of conductor patterns is composed of two conductor patterns overlapped and arranged with an insulating layer sandwiched therebetween, a first connecting portion, the two ends of the two conductor patterns are connected by the first connecting portion to connect the two conductor patterns in parallel, a second connecting portion, a plurality of groups of the pair of conductor patterns are connected in series by the second connecting portion, and the first connecting portion and the second connecting portion are arranged in a staggered position in the longer line direction of the coil pattern" (refer to Claim 1 of Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2015-18852

[0005] like Figure 8 As shown, the laminated electronic component disclosed in Patent Document 1 has a current concentration around the conductor pattern 103 of the first connection portion 101 and the second connection portion 102 (in the figure, the dotted line area), which may cause a temperature rise and cause a malfunction. Summary of the invention

[0006] An object of the present invention is to provide a laminated coil component that reduces current concentration around a connection portion of a conductor pattern and has high reliability.

[0007] The present disclosure includes the following aspects.

[0008] A laminated coil component comprising:

[0009] A laminated body formed by laminating insulating layers;

[0010] a coil disposed in the laminate; and

[0011] an external electrode disposed on a surface of the stack and electrically connected to the coil,

[0012] The laminated coil component is characterized in that:

[0013] The coil includes at least two coil conductor groups, and the coil conductor groups include at least two coil conductors connected in parallel via two connecting conductors.

[0014] The at least two coil conductor groups are connected in series via a connecting conductor.

[0015] The connection conductor connects the coil conductors between the two connection conductors of each coil conductor group.

[0016] In the laminated coil component described in [1] above, the cross-sectional area of ​​the connecting conductor is 2.0 times or more the cross-sectional area of ​​one coil conductor connected to the connecting conductor.

[0017] In the laminated coil component described in [1] or [2] above, a gap is formed between the coil conductor and the insulating layer.

[0018] According to the present disclosure, it is possible to provide a coil component that reduces current concentration around a connection portion of a conductor pattern and has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a perspective view schematically showing a laminated coil component 1 according to the present disclosure.

[0020] Figure 2 yes Figure 1 An exploded perspective view of the laminated coil component 1 is shown.

[0021] Figure 3 yes Figure 1 The laminated coil component 1 shown is a cross-sectional view taken along the line xx, and is a diagram for explaining the flow of current.

[0022] Figure 4 4 (a) to 4 (h) are plan views showing layer structures of laminated coil components of other forms.

[0023] Figure 5 It's overlapping. Figure 4 (a)~ Figure 4 Figure (d).

[0024] Figure 6 yes Figure 5 yy cross-sectional view of the stacked body shown.

[0025] Figure 7 is the current from Figure 6 The cross-sectional views 17c, d are diagrams for explaining the flow to 17e, f.

[0026] Figure 8 FIG. 1 is a diagram schematically showing a connection state of a conventional laminated coil component.

[0027] Description of Reference Numerals

[0028] 1… stacked coil component; 2… main body; 4, 5… external electrodes; 6a~6j… insulating layer; 7a~7h… coil conductor; 8a~8f… connecting conductor; 9a~9f… via hole; 11a~11c… connecting conductor; 12a~12c… via hole; 16a~16h… insulating layer; 17a~17h… coil conductor; 18a~18f… connecting conductor; 21a~21c… connecting conductor. DETAILED DESCRIPTION

[0029] Hereinafter, a laminated coil component 1 according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, the shapes and arrangements of the laminated coil component and each component of the present embodiment are not limited to the examples shown in the drawings.

[0030] The perspective view of the laminated coil component 1 of this embodiment is as follows Figure 1 As shown, the exploded perspective view of the main body of the laminated coil component 1 is as shown in Figure 2 In addition, the xx cross-sectional view of the laminated coil component 1 and the current flowing in the laminated coil component 1 are shown by Figure 3 However, the shapes and arrangements of the laminated coil components and components of the following embodiments are not limited to the examples shown in the drawings.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown in FIG. 1 , the laminated coil component 1 of the present embodiment is a laminated coil component having a substantially rectangular parallelepiped shape. Figure 1 The surface perpendicular to the L axis is called the "end surface", the surface perpendicular to the W axis is called the "side surface", and the surface perpendicular to the T axis is called the "upper and lower surfaces". The laminated coil component 1 generally includes a body 2 and external electrodes 4 and 5 provided on both end surfaces of the body 2. The body 2 includes a laminated body formed by stacking insulating layers and a coil provided in the laminated body. Figure 2As shown, the stacked body is composed of stacked insulating layers 6a to 6j (hereinafter, also collectively referred to as "insulating layer 6"). The coil is composed of coil conductors 7a to 7h (hereinafter, also collectively referred to as "coil conductor 7") connected by connecting conductors 8a to 8f (hereinafter, also collectively referred to as "connecting conductors 8") and connecting conductors 11a to 11c (hereinafter, also collectively referred to as "connecting conductors 11"). For the coil conductors, the coil conductors adjacent in the stacking direction form a group, and a coil conductor group is formed by connecting with two connecting conductors. That is, the coil conductors 7a and 7b are electrically connected in parallel to the external electrode 5 through the connecting conductor 8a to form the first coil conductor group. The coil conductors 7c and 7d are electrically connected in parallel through the connecting conductors 8b and 8c to form the second coil conductor group. The coil conductors 7e and 7f are electrically connected in parallel through the connecting conductors 8d and 8e to form the third coil conductor group. The coil conductors 7g and 7h are electrically connected in parallel via the connecting conductor 8f and the external electrode 4, forming the fourth coil conductor group. The first coil conductor group and the second coil conductor group are electrically connected in series via the connecting conductor 11a. The connecting conductor 11a connects the coil conductor 7b and the coil conductor 7c between the connecting conductor 8a of the first coil conductor group and the external electrode 5 and between the connecting conductors 8b and 8c of the second coil conductor group. The second coil conductor group and the third coil conductor group are electrically connected in series via the connecting conductor 11b. The connecting conductor 11b connects the coil conductor 7d and the coil conductor 7e between the connecting conductors 8b and 8c of the second coil conductor group and between the connecting conductors 8d and 8e of the third coil conductor group. The third coil conductor group and the fourth coil conductor group are electrically connected in series via the connecting conductor 11c. The connecting conductor 11c connects the coil conductor 7f and the coil conductor 7g between the connecting conductors 8d and 8e of the third coil conductor group and between the connecting conductor 8f of the fourth coil conductor group and the external electrode 4. As shown in FIG. Figure 3 As shown, by connecting the coil conductors as described above, current flows in parallel in the coil conductor group, and the DC resistance of the entire coil can be reduced, and heat generation can be suppressed.

[0032] In the laminated coil component 1 of the present embodiment, the main body 2 is composed of a laminate of insulating layers 6 and a coil embedded in the laminate.

[0033] In the laminated coil component of the present disclosure, the laminate is formed by laminating a plurality of insulating layers. In addition, in the laminated coil component of the present disclosure, the number of laminated insulating layers is not particularly limited.

[0034] The insulating layer 6 is preferably made of a magnetic body, and more preferably made of sintered ferrite. The sintered ferrite contains at least Fe, Ni, and Zn as main components. The sintered ferrite may further contain Cu.

[0035] In one embodiment, the sintered ferrite contains at least Fe, Ni, Zn, and Cu as main components.

[0036] In the above-mentioned sintered ferrite, the Fe content, calculated as Fe2O3, is preferably 40.0 mol% to 49.5 mol% (based on the total of main components, the same applies hereinafter), and more preferably 45.0 mol% to 49.5 mol%.

[0037] In the sintered ferrite, the Zn content is preferably 5.0 mol% to 35.0 mol% (based on the total of main components, the same applies hereinafter), and more preferably 10.0 mol% to 30.0 mol% in terms of ZnO.

[0038] In the sintered ferrite, the Cu content is preferably 4.0 mol% to 12.0 mol% (based on the total of main components, the same applies hereinafter), and more preferably 7.0 mol% to 10.0 mol% in terms of CuO.

[0039] In the above-mentioned sintered ferrite, the Ni content is not particularly limited, and may be the remainder of the above-mentioned other main components, namely, Fe, Zn, and Cu.

[0040] In one embodiment, for the above-mentioned sintered ferrite, Fe is converted into Fe2O3 and is greater than 40.0 mol% and less than 49.5 mol%, Zn is converted into ZnO and is greater than 5.0 mol% and less than 35.0 mol%, Cu is converted into CuO and is greater than 6.0 mol% and less than 12.0 mol%, and Ni is converted into NiO and is greater than 8.0 mol% and less than 40.0 mol%.

[0041] In the present disclosure, the above-mentioned sintered ferrite may also include additives. As additives of sintered ferrite, for example, Mn, Co, Sn, Bi, Si, etc. can be cited, but are not limited to this. The content (addition amount) of Mn, Co, Sn, Bi and Si is converted into Mn3O4, Co3O4, SnO2, Bi2O3 and SiO2, respectively, relative to a total of 100 parts by weight of the main components (Fe (converted into Fe2O3), Zn (converted into ZnO), Cu (converted into CuO) and Ni (converted into NiO)), preferably more than 0.1 parts by weight and less than 1 part by weight. In addition, the above-mentioned sintered ferrite may also include impurities that are inevitable in manufacturing.

[0042] The sintered ferrite may also contain, for example, Mn, Co, Sn, Bi, Si, etc. as additives. As additives of the sintered ferrite, for example, Mn, Co, Sn, Bi, Si, etc. may be cited, but are not limited thereto. The content (addition amount) of Mn, Co, Sn, Bi and Si is preferably more than 0.1 parts by weight and less than 1 part by weight, respectively, relative to a total of 100 parts by weight of the main components (Fe (converted into Fe2O3), Zn (converted into ZnO), Cu (converted into CuO) and Ni (converted into NiO)). In addition, the sintered ferrite may also include impurities that are inevitable in manufacturing.

[0043] The coil of the laminated coil component of the present disclosure includes at least two coil conductor groups, and the coil conductor group includes at least two coil conductors connected in parallel via two connecting conductors. The coil is formed by connecting the at least two coil conductor groups in series via a connecting conductor.

[0044] like Figure 2 As shown, the laminated coil component 1 of this embodiment includes four coil conductor groups. The coil conductors 7a and 7b are electrically connected in parallel to the external electrode 5 through the connecting conductor 8a, forming the first coil conductor group. Here, in addition to being electrically connected to the ends of the coil conductors 7a and 7b and functioning as an external electrode, the external electrode 5 also functions as a connecting conductor connecting the coil conductor 7a and the coil conductor 7b. The coil conductors 7c and 7d are electrically connected in parallel to the connecting conductors 8b and 8c to form the second coil conductor group. The coil conductors 7e and 7f are electrically connected in parallel to the connecting conductors 8d and 8e to form the third coil conductor group. The coil conductors 7g and 7h are electrically connected in parallel to the external electrode 4 through the connecting conductor 8f to form the fourth coil conductor group. Here, in addition to being electrically connected to the ends of the coil conductors 7g and 7h and functioning as an external electrode, the external electrode 4 also functions as a connecting conductor connecting the coil conductor 7g and the coil conductor 7h.

[0045] In the laminated coil component of the present disclosure, the coil conductors included in the coil conductor group are arranged adjacent to each other in a lamination direction. In the coil conductor group, the number of the coil conductors is two or more and five or less, preferably two.

[0046] In the laminated coil component of the present disclosure, it is preferable that the coil conductors included in each coil conductor group have the same shape and are provided at the same position when viewed in plan from the lamination direction.

[0047] In the stacked coil component 1 of the present embodiment, the 1st to 4th coil conductor groups respectively include coil conductors 7a, 7b, coil conductors 7c, 7d, coil conductors 7e, 7f and coil conductors 7g, 7h. When viewed from above in the stacking direction, the coil conductors included in each coil conductor group are arranged in the same shape and at the same position.

[0048] The thickness of the coil conductor is preferably 30 μm or more and 80 μm or less, and more preferably 40 μm or more and 70 μm or less. By making the thickness of the coil conductor 30 μm or more, the DC resistance can be reduced. By making the thickness of the coil conductor 80 μm or less, the coil component can be easily reduced in height and miniaturization.

[0049] In the laminated coil component of the present disclosure, the connection conductor connects the coil conductors adjacent to each other in the lamination direction in parallel. Therefore, two connection conductors are provided between two coil conductors adjacent to each other in the lamination direction.

[0050] The connecting conductor is not particularly limited as long as it can connect the coil conductors adjacent to each other in the stacking direction in parallel. Such a connecting conductor is usually arranged inside the stack, but an external electrode can also be used as a connecting conductor. When arranged inside the stack, the connecting conductor is preferably a via hole conductor arranged in a via hole penetrating the insulating layer.

[0051] The cross-sectional area of ​​the connecting conductor is preferably greater than or equal to the cross-sectional area of ​​the coil conductor to which the connecting conductor is connected, and more preferably greater than or equal to 1.5 times. By making the cross-sectional area of ​​the connecting conductor larger than the cross-sectional area of ​​the coil conductor, it is possible to avoid heat concentration in the connecting conductor. Here, the "cross-sectional area" of the connecting conductor is the cross-sectional area of ​​the smallest cross-sectional area perpendicular to the stacking direction.

[0052] In the laminated coil component 1 of the present embodiment, the connecting conductors 8a to 8f are via hole conductors provided in the via holes 9a to 9f (hereinafter, also collectively referred to as "via holes 9") provided in the insulating layer. In addition, the external electrodes 4 and 5 also function as connecting conductors. In more detail, the connecting conductor 8a is provided in the via hole 9a, and connects the coil conductors 7a and 7b in parallel with the external electrode 4. The connecting conductors 8b and 8c are provided in the via holes 9b and 9c, respectively, and connect the coil conductors 7c and 7d in parallel. The connecting conductors 8d and 8e are provided in the via holes 9d and 9e, respectively, and connect the coil conductors 7e and 7f in parallel. The connecting conductor 8f is provided in the via hole 9f, and connects the coil conductors 7g and 7h in parallel with the external electrode 5.

[0053] In the stacked coil component disclosed in the present invention, the connecting conductor connects the coil conductor groups adjacent in the stacking direction in series. Such a connecting conductor connects the two connecting conductors of each coil conductor group connected in series. That is, the connecting conductor connects the coil conductor between the two connecting conductors of one coil conductor group with the coil conductor between the two connecting conductors of another coil conductor group. In other words, the connecting conductor is connected to a portion that maintains the parallel structure of each coil conductor group. Preferably, the connecting conductor is a via conductor provided in a via hole penetrating the insulating layer.

[0054] In the laminated coil component 1 of the present embodiment, the connecting conductor 11a connects the coil conductor 7b and the coil conductor 7c between the connecting conductor 8a of the first coil conductor group and the external electrode 5 and between the connecting conductors 8b and 8c of the second coil conductor group, thereby electrically connecting the first coil conductor group and the second coil conductor group in series. The connecting conductor 11b connects the coil conductor 7d and the coil conductor 7e between the connecting conductors 8b and 8c of the second coil conductor group and between the connecting conductors 8d and 8e of the third coil conductor group, thereby electrically connecting the second coil conductor group and the third coil conductor group in series. The connecting conductor 11c connects the coil conductor 7f and the coil conductor 7g between the connecting conductors 8d and 8e of the third coil conductor group and between the connecting conductor 8f of the fourth coil conductor group and the external electrode 4, thereby electrically connecting the third coil conductor group and the fourth coil conductor group in series. By connecting the coil conductor groups using the connecting conductors in this way, the currents of the coil conductor groups can flow in parallel. In the laminated coil component 1 of the present embodiment, the connection conductors 11 a to 11 c are via-hole conductors provided in via holes 12 a to 12 c (hereinafter also collectively referred to as “via holes 12 ”) provided in the insulating layer.

[0055] The above-mentioned connecting conductor is preferably arranged to be biased toward one connecting conductor, so as to connect a plurality of coil conductor groups to form a coil shape. For example, when the coil conductor is divided into 10 equal parts between two connecting conductors (including the part connected to the connecting conductor), the above-mentioned connecting conductor is preferably connected to the area from the end to the third part, more preferably connected to the area to the second part, and further preferably connected to the area at the very end. In addition, when two connecting conductors are connected to one coil conductor group, one connecting conductor is connected to one end side of the coil conductor, and the other connecting conductor is connected to the other end side of the coil conductor. By arranging the connecting conductor in the area close to the end, the characteristics of the coil can be obtained more effectively.

[0056] The cross-sectional area of ​​the connecting conductor is preferably at least twice the cross-sectional area of ​​the coil conductor to which the connecting conductor is connected, and more preferably at least three times. By making the cross-sectional area of ​​the connecting conductor at least twice the cross-sectional area of ​​the coil conductor, it is possible to avoid heat concentration in the connecting conductor. Here, the "cross-sectional area" of the connecting conductor is the cross-sectional area of ​​the smallest cross-sectional area perpendicular to the stacking direction.

[0057] In the stacked coil component disclosed in the present invention, the above-mentioned connecting conductor connects the coil conductors between the two connecting conductors of each coil conductor group to each other. That is, when looking down from the stacking direction at two coil conductor groups adjacent to each other in the stacking direction and the connecting conductor connecting them, with respect to the positional relationship of the connecting conductor and the connecting conductor along the winding direction of the coil, in the upper coil conductor group, there are one connecting conductor, a connecting conductor, and another connecting conductor in sequence, and in the lower coil conductor group, there are one connecting conductor, a connecting conductor, and another connecting conductor in sequence. Furthermore, the connecting conductor exists between the above-mentioned another connecting conductor of the upper coil conductor group and the above-mentioned one connecting conductor of the lower coil conductor group. For example, in the present embodiment, as Figure 2 As shown, regarding the third coil conductor group including coil conductors 7e and 7f and the second coil conductor including coil conductors 7c and 7d, when viewed from the stacking direction, there are one connecting conductor 8e, a connecting conductor 11b, and another connecting conductor 8d of the third coil conductor group in the upper part, and there are one connecting conductor 8c, a connecting conductor 11b, and another connecting conductor 8b of the second coil conductor group in the lower part. Furthermore, the connecting conductor 11b is located between the above-mentioned another connecting conductor 8d of the third coil conductor group and the above-mentioned one connecting conductor 8c of the second coil conductor group.

[0058] In the stacked coil component disclosed in the present invention, when viewed from above in the stacking direction, the above-mentioned connecting conductor or connecting conductor, i.e., the via-hole conductor, is arranged at a position different from the via-hole conductor in the insulating layer adjacent in the stacking direction. In other words, when viewed from above in the stacking direction, the connecting conductor as the above-mentioned via-hole conductor is misaligned with the connecting conductor or connecting conductor in the insulating layer adjacent in the stacking direction. That is, when viewed from above in the stacking direction, the area where the above-mentioned via-hole conductor exists is completely not included in the area where the via-hole conductor in the insulating layer adjacent in the stacking direction exists, or does not include the area at all. By misaligning the via-hole conductors in the insulating layers adjacent to each other in the stacking direction when viewed from above in the stacking direction, the generation of stress, the generation of cracks, etc. caused by the difference between the shrinkage rate of the via-hole conductor and the shrinkage rate of the insulating layer during firing can be suppressed.

[0059] In the laminated coil component 1 of the present embodiment, when viewed from the stacking direction, the above-mentioned connecting conductor or connecting conductor, that is, the via-hole conductor, does not have a portion overlapping with the via-hole conductor in the insulating layer adjacent to the stacking direction. In this way, when viewed from the stacking direction, the via-hole conductors are arranged so that the via-hole conductors in the insulating layers adjacent to the stacking direction do not have overlapping portions, thereby further suppressing the generation of stress, the generation of cracks, etc.

[0060] In another embodiment, the link conductor or the connection conductor, that is, the via-hole conductor is provided so as to partially overlap with a via-hole conductor located in an insulating middle layer adjacent to the stacking direction when viewed in plan from the stacking direction.

[0061] pass Figure 4 (a)~ Figure 4 of (h), Figure 5 and Figure 6 The above-mentioned other forms of via hole arrangement will be described. Figure 4 (a)~ Figure 4 (h) respectively represent the insulating layers 16a to 16h and the coil conductors 17a to 17h, the connecting conductors 18a to 18f and the connecting conductors 21a to 21c provided thereon. These layers are stacked in order as follows: Figure 4 (a) is the lowest layer, Figure 4 (h) is the uppermost layer. Figure 5 It means that the above Figure 4 (a)~ Figure 4 FIG. 1 is a diagram showing the arrangement of the coil conductors 17a to 17d, the connecting conductors 18a and 18b, and the connection conductor 21a in the case of (d). Figure 6 yes Figure 5 A cross-sectional view of the stacked body taken along line yy. Figure 7 : is a diagram showing the flow of current in such a structure. In this embodiment, coil conductors 17a and 17b are connected in parallel via a connecting conductor 18a and an external electrode (not shown) to form a first coil conductor group. Coil conductors 17c and 17d are connected in parallel via connecting conductors 18b and 18c to form a second coil conductor group. Coil conductors 17e and 17f are connected in parallel via connecting conductors 18d and 18e to form a third coil conductor group. Coil conductors 17g and 17h are connected in parallel via a connecting conductor 18f and an external electrode (not shown) to form a fourth coil conductor group. The first coil conductor group and the second coil conductor group are connected in series via a connecting conductor 21a. The second coil conductor group and the third coil conductor group are connected in series via a connecting conductor 21b. The third coil conductor group and the fourth coil conductor group are connected in series via a connecting conductor 21c. As shown in FIG. Figure 5 and Figure 6As shown, in this embodiment, the connection conductor 18a, the connection conductor 21a and the connection conductor 18b are arranged in this order and partially overlapped. With such an arrangement, the current is not concentrated, the temperature rise can be suppressed, and the reliability of the coil can be improved.

[0062] The via hole conductors (connecting conductors and connecting conductors) overlap preferably by 2% to 90% of their length along the winding direction of the coil conductor, more preferably by 10% to 70%, and even more preferably by 20% to 60%.

[0063] The coil conductor, the connecting conductor and the connecting conductor are conductive layers including conductive materials. Preferably, the coil conductor, the connecting conductor and the connecting conductor are substantially composed of conductive materials. Such conductive materials are not particularly limited, but examples thereof include Au, Ag, Cu, Pd, Ni, etc. The conductive material is preferably Ag or Cu, and more preferably Ag. The conductive material may be only one kind or may be two or more kinds.

[0064] In the laminated coil component of the present disclosure, the external electrode is provided on the surface of the laminated body and is electrically connected to the coil.

[0065] The external electrode may be a single layer or a multi-layer. In one embodiment, the external electrode may be a multi-layer, preferably two or more layers and four or less layers, for example, three layers.

[0066] In the laminated coil component 1 of this embodiment, the external electrodes 4 and 5 are provided to cover both end surfaces of the body 2. The external electrodes are made of a conductive material, preferably one or more metal materials selected from Au, Ag, Pd, Ni, Sn and Cu.

[0067] In one embodiment, the external electrode is a multilayer including a layer containing Ag or Pd, a layer containing Ni or a layer containing Sn. In a preferred embodiment, the external electrode is composed of a layer containing Ag or Pd, a layer containing Ni and a layer containing Sn. Preferably, the above-mentioned layers are sequentially provided from the coil conductor side with a layer containing Ag or Pd, preferably a layer containing Ag, a layer containing Ni, and a layer containing Sn. Preferably, the layer containing Ag or Pd is a layer obtained by firing Ag paste or Pd paste, and the layer containing Ni and the layer containing Sn may be a plated layer.

[0068] The laminated coil component disclosed in the present invention preferably has a length of 0.4 mm to 3.2 mm, a width of 0.2 mm to 2.5 mm, and a height of 0.2 mm to 2.0 mm, and more preferably has a length of 0.6 mm to 2.0 mm, a width of 0.3 mm to 1.3 mm, and a height of 0.3 mm to 1.0 mm.

[0069] In a preferred embodiment, the laminated coil component of the present disclosure has a gap formed between the coil conductor and the insulating layer. For example, in the laminated coil component 1 of the present embodiment, a gap is provided at the boundary between the coil conductors 7a to 7h and the insulating layers 6b to 6i. By providing a gap between the coil conductor and the insulating layer, the generation of stress between the coil conductor and the laminate can be suppressed.

[0070] The laminated coil component 1 of the present embodiment described above is manufactured, for example, as follows. In the present embodiment, a mode in which the insulating layer 6 is formed of a ferrite material and a gap portion exists between the coil conductor 7 and the insulating layer 6 is described.

[0071] (1) Preparation of ferrite paste

[0072] First, a ferrite material is prepared. The ferrite material contains Fe, Zn and Ni as main components, and further contains Cu as desired. Generally, the main components of the ferrite material are substantially composed of oxides of Fe, Zn, Ni and Cu (ideally, Fe2O3, ZnO, NiO and CuO).

[0073] As ferrite materials, Fe2O3, ZnO, CuO, NiO and additional components as required are weighed to a specified composition, mixed and crushed. The crushed ferrite material is dried and pre-fired at 700-800°C to obtain a pre-fired powder. A specified amount of solvent (ketone solvent, etc.), resin (polyvinyl acetal, etc.) and plasticizer (alkyd plasticizer, etc.) are added to the pre-fired powder, and after kneading using a planetary mixer, etc., it is further dispersed by a three-roll mill, etc., so that a ferrite paste can be made. In addition, an organic binder such as polyvinyl butyral, an organic solvent such as ethanol, toluene, etc., is put into a ball mill together with PSZ balls, and mixed and crushed with the pre-fired powder prepared as described above. The obtained mixture can be formed into a sheet of a specified thickness, size, and shape using a scraper method, etc. to make a ferrite sheet.

[0074] In addition, it can be considered that the Fe content (converted into Fe2O3), Mn content (converted into Mn2O3), Cu content (converted into CuO), Zn content (converted into ZnO) and Ni content (converted into NiO) of the sintered ferrite are essentially no different from the Fe content (converted into Fe2O3), Mn content (converted into Mn2O3), Cu content (converted into CuO), Zn content (converted into ZnO) and Ni content (converted into NiO) of the ferrite material before firing.

[0075] (2) Preparation of conductive paste for coil conductor

[0076] First, a conductive material is prepared. As the conductive material, for example, Au, Ag, Cu, Pd, Ni, etc. can be cited, preferably Ag or Cu, more preferably Ag. A predetermined amount of powder of the conductive material is weighed, and kneaded with a predetermined amount of solvent (eugenol, etc.), resin (ethyl cellulose, etc.) and dispersant using a planetary mixer, etc., and then dispersed using a three-roll mill, etc., so that a conductive paste for a coil conductor can be prepared.

[0077] (3) Preparation of resin paste

[0078] A resin paste for forming the cavity is prepared. Such a resin paste can be prepared by adding a resin (acrylic resin, etc.) that disappears during firing to a solvent (isophorone, etc.).

[0079] (4) Manufacturing of laminated coil components

[0080] (4-1) Preparation of the main body

[0081] First, prepare the ferrite layer (with Figure 2 A specified number of ferrite sheets corresponding to the insulating layer 6a).

[0082] Next, prepare other ferrite sheets (with Figure 2 The resin paste is printed at the location where the gap is formed to form a resin paste layer.

[0083] Next, the conductive paste is printed on the portion where the coil conductor is to be formed to form a conductive paste layer (with Figure 2 corresponding to coil conductor 7a).

[0084] Next, in the area where the conductive paste layer is not formed, the ferrite paste is printed to the same height as the conductive paste layer.

[0085] Next, prepare other ferrite sheets (with Figure 2 A via hole (corresponding to the via hole 9a) is formed in the ferrite sheet, and a conductive paste is filled in the via hole (the conductive paste filled corresponds to the via hole 9a). Figure 2 corresponding to the connecting conductor 8a).

[0086] Next, the resin paste is printed at the location where the cavity is to be formed, thereby forming a resin paste layer.

[0087] Next, the conductive paste is printed on the portion where the coil conductor is to be formed, forming a conductive paste layer (with Figure 2 corresponding to coil conductor 7b).

[0088] Next, in the area where the conductive paste layer is not formed, the ferrite paste is printed to the same height as the conductive paste layer.

[0089] Next, prepare other ferrite sheets (with Figure 2 A via hole (corresponding to the via hole 12a) is formed in the ferrite sheet, and a conductive paste is filled in the via hole (the conductive paste filled corresponds to the via hole 12a). Figure 2 corresponding to the connecting conductor 11a).

[0090] Next, the resin paste is printed on the portion where the cavity is to be formed, thereby forming a resin paste layer.

[0091] Next, the conductive paste is printed on the portion where the coil conductor is to be formed to form a conductive paste layer (with Figure 2 corresponding to coil conductor 7c).

[0092] Repeat the above process and finally prepare the specified quantity (with Figure 2 The insulating layer 6j corresponds to a ferrite sheet, such as Figure 2 As shown, insulating layers 6a to 6j are stacked. The stacked body of the stacked sheets is pressed under heating and pressure conditions to obtain a stacked body block as an element assembly.

[0093] Next, the stacked body block is cut by a dicer or the like to be individualized into devices.

[0094] The obtained element is subjected to a barrel grinding process to grind the corners of the element and form a rounded corner. The barrel grinding process can be performed on the unfired laminated body or on the fired laminated body. In addition, the barrel grinding process can be either a dry process or a wet process. The barrel grinding process can be a method of rubbing the elements together or a method of barrel grinding them together with a medium.

[0095] After the barrel grinding process, the element is fired at a temperature of, for example, 880°C or higher and 920°C or lower to obtain the main body 2 of the laminated coil component 1. During the firing, the resin paste layer disappears, and a void portion is generated in the portion where the resin paste layer exists. The existence of such a void portion can reduce the generation of stress caused by the contraction of the fired ferrite paste layer and the conductive paste layer.

[0096] (4-2) Formation of External Electrodes

[0097] Next, an Ag paste containing Ag and glass for forming an external electrode is applied to the end surface of the body 2 and fired to form a base electrode. Next, a Ni film and a Sn film are sequentially formed on the base electrode by electroplating to form an external electrode. Figure 1 The laminated coil component 1 is as shown.

[0098] As mentioned above, although one embodiment of the present invention has been described, this embodiment can be modified in various ways.

[0099] For example, in the above, ferrite sheets corresponding to the respective insulating layers are prepared, coil patterns are printed on the sheets, and they are crimped to obtain the element. However, all the layers may be printed sequentially to obtain the element.

[0100] Industrial Applicability

[0101] The laminated coil component of the present disclosure can be used in a wide variety of applications such as an inductor.

Claims

1. A laminated coil component comprising: A laminated body formed by laminating insulating layers; a coil disposed in the laminate; and an external electrode disposed on a surface of the laminate and electrically connected to the coil, The laminated coil component is characterized in that: The coil includes at least two coil conductor groups, and the coil conductor group includes at least two coil conductors connected in parallel via two connecting conductors. The at least two coil conductor groups are connected in series via a connection conductor independent of the connection conductor. The connection conductor connects the coil conductors between two connection conductors of each coil conductor group.

2. The laminated coil component according to claim 1, wherein: The cross-sectional area of ​​the connection conductor is 2.0 times or more the cross-sectional area of ​​a coil conductor connected to the connection conductor.

3. The laminated coil component according to claim 1 or 2, characterized in that: A gap is formed between the coil conductor and the insulating layer.

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